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Randomized Controlled Trial Comparing Landmark and Ultrasound-Guided Glossopharyngeal Nerve in Eagle Syndrome

Randomized Controlled Trial Comparing Landmark and Ultrasound-Guided Glossopharyngeal Nerve in... Abstract Introduction The glossopharyngeal nerve lies posterior to the internal carotid artery at the submandibular region. The primary objective of this study was to compare ultrasound-guided glossopharyngeal nerve block (UGPNB) and landmark glossopharyngeal nerve block (GPNB). Materials & Methods Inclusion criteria were patients with unilateral Eagle syndrome and ear pain. Group UGPNB (N = 25) received three UGPNBs at weekly intervals with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone. Group GPNB (N = 26) received landmark GPNB. Pain intensity was evaluated with the numerical rating scale (NRS) before every block, 30 minutes after every block, and at one, three, and five weeks after the third block. Quality of life, assessed using the Brief Pain Inventory (BPI), and satisfaction scores were noted. Results NRS scores before the second and third blocks and a week after were significantly lower in group UGPNB and comparable at weeks 3 and 5. NRS scores 30 minutes after every block were significantly decreased from the preblock values but were comparable between groups. In 68% of patients, a curvilinear probe delineated the internal carotid artery (ICA). Out-of-plane needle trajectory was required in 64% of patients. BPI and satisfaction scores were significantly better in the UGPNB group in the “block” weeks. Conclusions UGPNB with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone injected posterior to the ICA in the submandibular region provides better pain relief for at least a week compared with an extraoral landmark technique when three weekly consecutive blocks are given. In most patients, a curvilinear probe and out-of-plane needle trajectory are most suitable for ultrasound block. Ultrasound, Glossopharyngeal Nerve Block, Eagle Syndrome Introduction Glossopharyngeal neuralgia (GPN) is a rare medical condition with an incidence of 0.7/100,000 every year with idiopathic and secondary causes [1]. The most common secondary cause of GPN is an elongated styloid process >3 cm in length (normal = 2.5–3 cm) or calcification of the stylohyoid ligament. It is commonly diagnosed by a palpable styloid process in the tonsillar fossa and an enlarged styloid process on x-ray in Waters view [2]. This causes compression or irritation of the surrounding glossopharyngeal nerve, resulting in symptoms of GPN in the distribution of the glossopharyngeal nerve, which includes brief stabbing pain in throat, base of tongue, tonsillar fossa, or beneath the angle of the mandible on the affected side. Pain is abrupt in onset, and termination and is commonly provoked by swallowing, talking, or coughing. Pain may radiate to the ears, as proximally in the course of the nerve there are contributions by the auricular and pharyngeal branches of the vagus. This entity is called Eagle syndrome [1–5]. GPN is a challenging condition to manage, and its pain can be debilitating. Treatment options for Eagle syndrome are medical therapy with various drugs like nonsteroidal anti-inflammatory drugs, anticonvulsants, and tricyclic antidepressants. Medical management may be effective for many patients, but side effects are often difficult to tolerate. There is clear value to pursuing effective interventional therapies including percutaneous blocks like glossopharyngeal nerve block (GPNB) [1,3,4]. Frequently for effective pain management, medical therapy is combined with GPNB, which is usually given by an extraoral landmark technique where local anesthetic is deposited at the midpoint of the mastoid process and angle of the mandible [1,5–7]. Disadvantages of the extraoral technique for GPNB are possible injury to closely located vessels and nerves like the internal carotid artery (ICA), internal jugular vein (IJV), external jugular vein (EJV), vagus nerve, hypoglossal nerve, sympathetic chain, and facial nerve. Also, anatomical variation of the above and difficult landmark assessment in obese individuals may result in ineffective blocks and complications. Anatomically, the glossopharyngeal nerve exits the skull through the anteromedial aspect of the jugular foramen, anterior to the vagus and accessory nerve, and passes forward between the ICA and IJV. It lies posterior to the ICA deep in the styloid process and further in its course passes anterior to the ICA between the ICA and external carotid artery (ECA) (Figure 1) [6–9]. Thus, in the submandibular region, it lies posterior to the ICA. In recent years, ultrasound-guided nerve blocks for chronic pain have shown various advantages over landmark techniques; however, descriptions of ultrasound-guided glossopharyngeal nerve block (UGPNB) are scarce [8]. A case report in a patient with oral cancer described UGPNB by depositing phenol posterior to the ICA in the submandibular region, which is the anatomical location of the glossopharyngeal nerve, with good pain relief [9]. Figure 1 Open in new tabDownload slide Glossopharyngeal nerve posterior to the internal carotid artery in the submandibular region. Figure 1 Open in new tabDownload slide Glossopharyngeal nerve posterior to the internal carotid artery in the submandibular region. To the best of our knowledge, there are no randomized studies on UGPNB comparing it with the landmark technique. The hypothesis of the present study was that UGPNB performed by depositing local anesthetic posterior to the internal carotid artery in the submandibular region would result in superior pain control compared with the extraoral landmark technique. The primary objective of the present study was to compare the numerical rating scale (NRS) between patients given UGPNB and extraoral landmark GPNB at three weekly blocks and at follow-up one, three, and five weeks after the third block. A secondary objective was to compare quality of life by BPI scores, rescue medications, and satisfaction scores between the two groups in terms of the above timelines. As there is only one case report on UGPNB, the present study also determined that ultrasound probe (linear or curvilinear) best delineates the ICA and needle trajectory (in plane or out of plane) devoid of blood vessels to reach the posterior part of the ICA in the submandibular region to perform the block. Methods After institutional ethics committee approval and informed written consent, this prospective randomized, controlled, nonblinded study was conducted in the pain clinic of the Department of Anaesthesiology, Critical Care and Pain Medicine at All India Institute of Medical Sciences, New Delhi, between January 2015 and December 2018. Inclusion criteria were adult patients in the age group of 18–80 years with a diagnosis of unilateral Eagle syndrome and radiating ear pain. Exclusion criteria included patient refusal, known diabetes mellitus, ear and throat pathology, central nervous system pathology, local site infection, allergy to local anesthetics, sepsis, coagulopathy, behavioral abnormalities, and BMI >30. All patients diagnosed with Eagle syndrome in the Department of Otorhinology with a visual analog scale score >3 were referred to the pain clinic for further pain management [2]. Only patients with unilateral Eagle syndrome with ear pain on the affected side were recruited for the present study. All patients were given standard medical therapy of one oral tablet of pregabalin 75 mg once a day, oral tablet duloxetine 20 mg once a day, and one tablet of etoricoxib 120 mg once a day. With the above treatment, when the reported NRS was >5, patients were recruited and randomized to the study groups by a computer-generated random table. All recruited patients agreed to take part in the study. A total of 51 patients were recruited and divided into two groups; Group UGPNB (N = 25), where three UGPNBs at an interval of one week with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone were given, and Group GPNB (N = 26), where three landmark GPNBs at an interval of one week with similar drug as in Group UGPNB were given. Medical treatment was continued in all patients in both groups for the entire period of the study. All patients were given weekly GPNBs according to their assigned group for three consecutive weeks, and follow-up occurred at one week, three weeks, and five weeks after the third block. If a patient in either of the groups reported an NRS of >5 before the scheduled block or at follow-up, rescue medication with oral tramadol 50 mg once a day, up to a maximum of three times daily, was given. All blocks were given in the block area of the outpatient pain department (OPD) under strict aseptic precautions under standard monitoring of electrocardiogram (ECG), oxygen saturation (SPO2), and noninvasive blood pressure (NIBP). Intravenous access was obtained before the block was performed. For UGPNB, patients were laid supine with their neck turned to the opposite side (Figure 2). The ipsilateral neck of the patient was scanned using an ultrasonography machine (FUJIFI SonoSite Edge, Linear probe 13–6 MHz) from the base of the neck to look for the common carotid artery and IJV; position was confirmed by colored Doppler (Figure 2). The common carotid artery was traced upwards until bifurcation to the ICA and ECA was seen. The ICA after bifurcation lies posterior and deep to the ECA and was traced with the ultrasound probe upwards until the submandibular region between the mastoid process and the angle of the mandible was reached (Figure 3). If delineation of vessels was difficult with a low-frequency linear probe, a high-frequency curvilinear probe was used (FUJIFI SonoSite Edgelow frequency 2–5 MHz) and noted. The area posterior to the ICA and in the intended trajectory of the needle (in plane or out of plane) was scanned for presence of blood vessels by Doppler (Figure 3). The shortest distance to reach the posterior ICA devoid of blood vessels was selected as the final needle trajectory. In an out-of-plane needle trajectory, the needle was always passed from the Caudad side of the probe. In an in-plane needle trajectory, the needle was always passed from the posterior to anterior side. If vessels were found in both in-plane and out-of-plane trajectories to reach the posterior part of the ICA, the placement of the needle tip was protocolized to be placed at, in the following order: between the IJV and the ICA (as beyond the styloid process glossopharyngeal nerve lies between the IJV and the ICA); if not possible due to the presence of blood vessels in the needle trajectory, the needle was placed medial to the ICA; and if both were not possible due to the presence of vessels, the needle tip was directed above the ICA. A 26-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block without any prior local anesthesia (Figure 4). After the needle tip was placed at the desired location, aspiration for blood was done, and 0.1 mL of saline was injected to assess the spread. After this, 1.5 mL of 0.5% bupivacaine 7.5 mg with 20 mg of depomedrol (methylprednisolone injectable suspension) was injected, and the extension tubing was flushed with saline after the block. The spread of drug was confirmed in real time using ultrasound. The type of probe and needle trajectory were noted. Figure 2 Open in new tabDownload slide Head turned to the opposite side and initial scanning with linear probe, tracing the internal carotid artery from the base of the neck to the submandibular region. Figure 2 Open in new tabDownload slide Head turned to the opposite side and initial scanning with linear probe, tracing the internal carotid artery from the base of the neck to the submandibular region. Figure 3 Open in new tabDownload slide Twenty-six-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block. Figure 3 Open in new tabDownload slide Twenty-six-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block. Figure 4 Open in new tabDownload slide Final scan with curvilinear probe in the submandibular region delineating internal carotid artery (ICA), external carotid artery, and internal jugular vein. The needle trajectory in this patient is out of plane toward the lateral part of the ICA for ultrasound-guided glossopharyngeal nerve block. Figure 4 Open in new tabDownload slide Final scan with curvilinear probe in the submandibular region delineating internal carotid artery (ICA), external carotid artery, and internal jugular vein. The needle trajectory in this patient is out of plane toward the lateral part of the ICA for ultrasound-guided glossopharyngeal nerve block. An extraoral approach by landmark technique was performed as previously described, and a similar amount of drug was injected [5]. NRS was assessed at all time points by a third observer who was blinded to the technique used. All patients were observed for a period of 30 minutes in the recovery area before discharge. NRS was noted before every block, 30 minutes after every block, and at one, three, and five weeks after the third block. Quality of life by Brief Pain Inventory [10] and satisfaction scores (0 = not satisfied and 10 = very much satisfied) were also noted at the above time intervals. Complications like hoarseness, facial palsy, blood on aspiration, and sympathetic blockade were noted. SS was involved in the conduct, acquisition of data, and analysis. JP was involved in planning, conduct, conception, design, and the final draft. Statistical Analysis A previous study compared NRS scores in patients who received medical therapy and GPNB using a landmark technique [1]. There was reduction in NRS scores from a baseline of 5 ± 0.8 to 2 ± 0.8 at the end of two months in the GPNB group. The sample size for this study was calculated considering the change in NRS scores in Group UGPNB from a baseline of 5 ± 0.8 to 2 ± 0.8 at two months and assuming a change of one unit more in Group GPNB compared with Group UGPNB, that is, four units from baseline in two months. To achieve 90% power with a 5% level of significance, we required 25 samples in each group. Statistical analysis was carried out using Stata 12.0 (StataCorp, College Station, TX, USA). Data are presented as number (percentage), mean ± SD, or median (minimum–maximum), as appropriate. Baseline continuous variables and categorical variables were compared between the groups using the unpaired t test/Wilcoxon rank-sum test and chi-square test/Fisher exact test, respectively. The primary outcome variable, NRS, was assessed for normality using the Shapiro-Wilks test. NRS scores over a period of time were analyzed using the Wilcoxon rank-sum test once the date did not follow a normal distribution. Quality of pain, assessed using the Brief Pain Questionnaire, was analyzed between the groups using the chi-square test for trend. Vital parameters over a period of time between the groups were assessed using the generalized estimating equation (GEE). Complications of three blocks were compared between the groups using the Fisher exact test. P values <0.05 were considered statistically significant. Results Both groups were comparable in demographics, duration of illness, length of styloid process, site of GPN, and duration of illness (Table 1). Table 1 Demographics and baseline disease parameters Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 1 Demographics and baseline disease parameters Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab In intergroup analysis, baseline NRS was comparable between the groups (P = 0.548) (Table 2). NRS scores 30 minutes after every block were comparable between the groups (Table 3). However, a week after each block, NRS was significantly lower in Group UGPNB compared with Group GPNB (P = 0.011, P = 0.004, P = 0.034, respectively) (Table 2). NRS scores became comparable at three and five weeks after the third block (P = 0.136, P = 0.202, respectively) (Table 2). Table 2 NRS before first, second, and third blocks and at follow-up at weeks 6 and 8: Intergroup analysis NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. † NRS before block. ‡ NRS at follow-up. Open in new tab Table 2 NRS before first, second, and third blocks and at follow-up at weeks 6 and 8: Intergroup analysis NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. † NRS before block. ‡ NRS at follow-up. Open in new tab Table 3 NRS 30 minutes after block: Intergroup analysis NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 3 NRS 30 minutes after block: Intergroup analysis NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab In intragroup analysis, at each block, NRS scores 30 minutes postblock were significantly lower than preblock NRS scores in both groups (P < 0.001) (Table 4). In both groups, at each time frame NRS scores were lower than baseline NRS scores (P < 0.001); however, the average NRS score was >3 before the second and third blocks in Group GPNB (Table 5). Rescue medications were not required by any patients in either group. Table 4 NRS before and 30 minutes after the block: Intragroup analysis Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 4 NRS before and 30 minutes after the block: Intragroup analysis Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 5 Baseline NRS vs NRS at follow-up: Intragroup analysis Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 5 Baseline NRS vs NRS at follow-up: Intragroup analysis Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Comparison of quality of life by BPI revealed a significant reduction in average pain intensity from mild pain to no pain in Group UGPNB at the second, third, and fourth weeks after the third block compared with Group GPNB (P = 0.002, P = 0.002, P = 0.035, respectively). There was a significant reduction in right now pain intensity from moderate to mild pain in Group UGPNB compared with Group GPNB at week 3 (P = 0.007) and a significant reduction in pain relief in Group UGPNB at the second visit vs Group GPNB (P = 0.023) when compared with the first visit. Least pain and worst pain were comparable at eight weeks. There was a significant reduction from mild interference to no interference in general activity in Group UGPNB at the second and third visits compared with Group GPNB (P = 0.017, P = 0.004, respectively). Mood was significantly better, from mild interference to no interference in Group UGPNB compared with Group GPNB at the second and third weeks (P = 0.037, P = 0.023, respectively). All other parameters were comparable. Satisfaction scores at week 2 were significantly higher in Group UGPNB (P = 0.010) (Table 6). Table 6 Satisfaction scores at each visit Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 GPNB = landmark glossopharyngeal nerve block; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 6 Satisfaction scores at each visit Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 GPNB = landmark glossopharyngeal nerve block; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Probe and Needle Trajectory to Perform UGPNB In 68% of patients, a curvilinear probe was used to delineate the ICA (Table 7). Out-of-plane needle trajectory was required in 64% of patients to perform the block (Table 8). In 56% of patients the needle tip was placed posterior to the ICA, in 16% of patients the needle tip was placed superior to the ICA, in 20% of patients the needle tip was placed medial to the ICA, and in the remaining 8% of patients the needle tip was placed between the ICA and IJV (Table 9). Table 7 Type of ultrasound probe used Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 7 Type of ultrasound probe used Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 8 Needle trajectory in the UGPNB group Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 8 Needle trajectory in the UGPNB group Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 9 Needle tip position with respect to the internal carotid artery Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) ICA = internal carotid artery; IJV = internal jugular vein. Open in new tab Table 9 Needle tip position with respect to the internal carotid artery Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) ICA = internal carotid artery; IJV = internal jugular vein. Open in new tab In Group UGPNB, when a block was performed with the needle tip posterior to the ICA, hoarseness was seen in 28% of patients during the first block, 14.3% during the second block, and in 14.3% patients during the third block. None of the patients had facial palsy. When the needle tip was anterior to the ICA, hoarseness was seen in 40% of patients during the first block, 40% of patients during the second block, and 20% of patients during the third block. None of the patients had facial palsy. When the needle tip was between the ICA and IJV, hoarseness was seen in 100% of patients during the first, second, and third blocks. None of the patients had facial palsy. When the needle tip position was above the ICA, one of the patients had hoarseness, but 50% of patients had facial palsy (Table 10). Thus, hoarseness was seen maximally when the needle tip was between the ICA and IJV and facial palsy was seen maximally when the needle tip was placed superior to the ICA. Complications of hoarseness and facial palsy were comparable between the groups (P = 0.68). NRS >3 was not seen in any patients when the needle was placed posterior to the ICA and was seen maximally in patients when the needle was placed superior to the ICA (Table 10). Complications like hematoma, intraocular injection, arrhythmias, and syncope were not seen in any patient in either group. Table 10 Complications in the UGPNB group with different needle tip positions at each block Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 ICA = internal carotid artery; IJV = internal jugular vein; NRS = numerical rating scale; UGPNB =ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 10 Complications in the UGPNB group with different needle tip positions at each block Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 ICA = internal carotid artery; IJV = internal jugular vein; NRS = numerical rating scale; UGPNB =ultrasound-guided glossopharyngeal nerve block. Open in new tab Discussion Three consecutive weekly UGPNBs for Eagle syndrome, performed by deposition of 1.5 mL of ropivacaine and dexamethasone posterior to the ICA in the submandibular region, resulted in significant pain reduction for at least a week after each block compared with the extraoral landmark technique. For UGPNB, in more than half of the patients, a curved low-frequency ultrasound probe and out-of-plane needle trajectory were most suitable to avoid vessels in the needle trajectory. For management of glossopharyngeal neuralgia, combining GPNB with medical therapy is better than medical therapy alone [4]. However, UGPNB has not been extensively studied or evaluated in the treatment of GPN. A single case report by Bedder et al. in 1985 described UGPNB in a patient with carcinoma of the tongue who had severe pain in the distribution of the glossopharyngeal nerve. The author used the ICA as a landmark and performed UGPNB with a 7.5-MHz imaging transducer coupled with a 5-MHz doppler transducer kept below the mastoid process and tilted caudally to visualize the ICA. Block was performed with a short-bevel 22-G short needle via an in-plane technique with 2.5 mL of neurolytic agent, and 100% alcohol was injected posterior to the ICA with very good pain relief and no complications [9]. Recently Azman et al. described UGPNB in cadavers, where the nerve was traced distally at the level of the middle constrictor muscle superficial to the anteroposterior pharyngeal wall where the hyoid bone was identified. Though the authors couldn’t visualize GPN on ultrasound, UGPNB was proposed by depositing local anesthetic into the distal parapharyngeal space. The authors sensed that distal block would be safer, as it is away from vital structures like the carotid, vagus, spinal accessory, and hypoglossal [11]. As this block was performed after a proximal contribution of the auricular branch of the vagus nerve to the glossopharyngeal nerve, it probably would not be effective in the patients recruited in the present study who presented with GPN with auricular symptoms. Further studies in patients with GPN without auricular symptoms with the distal block as described by Azman et al. are suggested [11]. Maher et al. performed UGPNB in a patient with Eagle syndrome using a peristyloid approach. They scanned the neck using a linear probe and located the styloid process, mastoid process, and mandible and then injected local anesthetic around it, following which the patient had good pain relief [6]. However, the styloid process might not always be visible in all patients, as some cases of Eagle syndrome are secondary to calcification of the stylohyoid ligament, rather than ossification making identification of the styloid process difficult. Anatomically the glossopharyngeal nerve is a very small nerve and is not visible on ultrasound. Thus, in the present study, pulsations of the ICA were taken as a landmark for UGPNB, as pulsations are clearly visible on ultrasound and vessels can also be confirmed with doppler. Fluoroscopy techniques have recently been used for glossopharyngeal neuralgia; however, this requires a special area to perform the block and thus has its limitations [12]. Similarly, percutaneous radiofrequency thermocoagulation after confirmation of sensory stimulation of the glossopharyngeal nerve has been found to be effective for long-term pain relief; however, all these techniques require a prescanning with fluoroscopy, which again requires a specialized area to perform the block [13]. The advantage of the present ultrasound technique is that there is no requirement of a specialized area to perform the block and the proposed UGPNB can easily be performed in the OPD. The above procedures require a needle size of at least 22 G, which might be uncomfortable for the patient. Use of a 26-G needle in the proposed block does not require another needle prick for prior local anesthesia before the block and is well tolerated by the patients. Both techniques in the present study are essentially field blocks, as the nerve was neither visualized nor localized by other techniques. We feel that similar pain relief at 30 minutes postblock points to the field effect; however, a longer effect of UGPNB compared with the landmark technique points to closer deposition of drug to the nerve when the ICA is taken as a landmark on ultrasound. Further studies with prior confirmation of GPN by sensory stimulation and with a smaller volume of drug are recommended. Limitations of the present study were inability to comment on anatomic variation of the glossopharyngeal nerve due to nonvisibility of the glossopharyngeal nerve on ultrasound. However, favorable results point to close location of the glossopharyngeal nerve to the ICA and thus effectiveness of the present approach. This study was not powered to comment on the superiority of various needle to positions with respect to ICA. Further cadaver studies in this regard are proposed. Another limitation was that the patient and the operator were not blinded; however, NRS was recorded by a third observer who was blinded to the procedure. Self-remitting hoarseness occurred maximally when the needle tip was placed between the ICA and the IJV, and self-remitting facial palsy occurred maximally when the needle was superficial to the ICA, probably due to the superficial location of the facial nerve. Pain relief was maximal when the needle tip was posterior to the ICA, and the least pain relief was seen when the needle tip was between the ICA and IJV. However, the present study is underpowered to determine complications and pain relief with different needle positions. The use of a curvilinear probe delineated the vessels better in the present study; however, further studies with a low-frequency probe with a smaller footprint are recommended. There was significant improvement in mood, average pain, and general activity in Group UGPNB in the weeks that the block was given, probably because of better pain relief with the ultrasound technique. To conclude, UGPNB with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone injected posterior to the ICA in the submandibular region provides better pain relief for at least a week compared with an extraoral landmark technique when three weekly consecutive blocks are given. However, NRS is comparable at three and five weeks after the third block. Mood and general activity are better with UGPNB. In most patients, a curvilinear probe and out-of-plane needle trajectory are most suitable for the ultrasound block. Funding sources: No funding. Conflicts of interest: None. References 1 Singh PM , Kaur M, Trikha A. An uncommonly common: Glossopharyngeal neuralgia . Ann Indian Acad Neurol 2013 ; 16 ( 1 ): 1 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 2 Raina D , Gothi R, Rajan S. Eagle syndrome . Indian J Radiol Imaging 2009 ; 19 ( 2 ): 107 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 3 Moulin D , Boulanger A, Clark A, et al. . Pharmacological management of chronic neuropathic pain: Revised consensus statement from the Canadian Pain Society . Pain Res Manag 2014 ; 19 ( 6 ): 328 – 35 . Google Scholar Crossref Search ADS PubMed WorldCat 4 Dworkin RH , O’Connor AB, Backonja M, et al. . Pharmacologic management of neuropathic pain: Evidence-based recommendations . Pain 2007 ; 132 ( 3 ): 237 – 51 . Google Scholar Crossref Search ADS PubMed WorldCat 5 Singh PM , Dehran M, Mohan VK, Trikha A, Kaur M. Analgesic efficacy and safety of medical therapy alone vs combined medical therapy and extraoral glossopharyngeal nerve block in glossopharyngeal neuralgia . Pain Med 2013 ; 14 ( 1 ): 93 – 102 . Google Scholar Crossref Search ADS PubMed WorldCat 6 Maher T , Shankar H. Ultrasound-guided peristyloid steroid injection for Eagle syndrome . Pain Pract 2017 ; 17 ( 4 ): 554 – 7 . Google Scholar Crossref Search ADS PubMed WorldCat 7 Pintaric TS. Upper airway blocks for awake difficult airway management . Acta Clin Croat 2016 ; 55(Suppl 1 ): 85 – 9 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 8 Barrington MJ , Uda Y. Did ultrasound fulfill the promise of safety in regional anesthesia? Curr Opin Anaesthesiol 2018 ; 31 ( 5 ): 649 – 55 . Google Scholar Crossref Search ADS PubMed WorldCat 9 Bedder MD , Lindsay D. Glossopharyngeal nerve block using ultrasound guidance: A case report of a new technique . Reg Anesth 1989 ; 14 ( 6 ): 304 – 7 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 10 Cleeland CS , Ryan KM. Pain assessment: Global use of the Brief Pain Inventory . Ann Acad Med Singapore 1994 ; 23 ( 2 ): 129 – 38 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 11 Ažman J , Stopar Pintaric T, Cvetko E, Vlassakov K. Ultrasound-guided glossopharyngeal nerve block: A cadaver and a volunteer sonoanatomy study . Reg Anesth Pain Med 2017 ; 42 ( 2 ): 252 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 12 Telischak NA , Heit JJ, Campos LW, Choudhri OA, Do HM, Qian X. Fluoroscopic C-arm and CT-guided selective radiofrequency ablation for trigeminal and glossopharyngeal facial pain syndromes . Pain Med 2018 ; 19 ( 1 ): 130 – 41 . Google Scholar Crossref Search ADS PubMed WorldCat 13 Song L , He L, Pei Q, et al. . CT-guided percutaneous radiofrequency thermocoagulation for glossopharyngeal neuralgia: A retrospective clinical study of 117 cases . Clin Neurol Neurosurg 2019 ; 178 : 42 – 5 . Google Scholar Crossref Search ADS PubMed WorldCat © 2020 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Pain Medicine Oxford University Press

Randomized Controlled Trial Comparing Landmark and Ultrasound-Guided Glossopharyngeal Nerve in Eagle Syndrome

Pain Medicine , Volume 21 (6) – Jun 1, 2020

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Oxford University Press
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© 2020 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
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1526-2375
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1526-4637
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10.1093/pm/pnz370
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Abstract

Abstract Introduction The glossopharyngeal nerve lies posterior to the internal carotid artery at the submandibular region. The primary objective of this study was to compare ultrasound-guided glossopharyngeal nerve block (UGPNB) and landmark glossopharyngeal nerve block (GPNB). Materials & Methods Inclusion criteria were patients with unilateral Eagle syndrome and ear pain. Group UGPNB (N = 25) received three UGPNBs at weekly intervals with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone. Group GPNB (N = 26) received landmark GPNB. Pain intensity was evaluated with the numerical rating scale (NRS) before every block, 30 minutes after every block, and at one, three, and five weeks after the third block. Quality of life, assessed using the Brief Pain Inventory (BPI), and satisfaction scores were noted. Results NRS scores before the second and third blocks and a week after were significantly lower in group UGPNB and comparable at weeks 3 and 5. NRS scores 30 minutes after every block were significantly decreased from the preblock values but were comparable between groups. In 68% of patients, a curvilinear probe delineated the internal carotid artery (ICA). Out-of-plane needle trajectory was required in 64% of patients. BPI and satisfaction scores were significantly better in the UGPNB group in the “block” weeks. Conclusions UGPNB with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone injected posterior to the ICA in the submandibular region provides better pain relief for at least a week compared with an extraoral landmark technique when three weekly consecutive blocks are given. In most patients, a curvilinear probe and out-of-plane needle trajectory are most suitable for ultrasound block. Ultrasound, Glossopharyngeal Nerve Block, Eagle Syndrome Introduction Glossopharyngeal neuralgia (GPN) is a rare medical condition with an incidence of 0.7/100,000 every year with idiopathic and secondary causes [1]. The most common secondary cause of GPN is an elongated styloid process >3 cm in length (normal = 2.5–3 cm) or calcification of the stylohyoid ligament. It is commonly diagnosed by a palpable styloid process in the tonsillar fossa and an enlarged styloid process on x-ray in Waters view [2]. This causes compression or irritation of the surrounding glossopharyngeal nerve, resulting in symptoms of GPN in the distribution of the glossopharyngeal nerve, which includes brief stabbing pain in throat, base of tongue, tonsillar fossa, or beneath the angle of the mandible on the affected side. Pain is abrupt in onset, and termination and is commonly provoked by swallowing, talking, or coughing. Pain may radiate to the ears, as proximally in the course of the nerve there are contributions by the auricular and pharyngeal branches of the vagus. This entity is called Eagle syndrome [1–5]. GPN is a challenging condition to manage, and its pain can be debilitating. Treatment options for Eagle syndrome are medical therapy with various drugs like nonsteroidal anti-inflammatory drugs, anticonvulsants, and tricyclic antidepressants. Medical management may be effective for many patients, but side effects are often difficult to tolerate. There is clear value to pursuing effective interventional therapies including percutaneous blocks like glossopharyngeal nerve block (GPNB) [1,3,4]. Frequently for effective pain management, medical therapy is combined with GPNB, which is usually given by an extraoral landmark technique where local anesthetic is deposited at the midpoint of the mastoid process and angle of the mandible [1,5–7]. Disadvantages of the extraoral technique for GPNB are possible injury to closely located vessels and nerves like the internal carotid artery (ICA), internal jugular vein (IJV), external jugular vein (EJV), vagus nerve, hypoglossal nerve, sympathetic chain, and facial nerve. Also, anatomical variation of the above and difficult landmark assessment in obese individuals may result in ineffective blocks and complications. Anatomically, the glossopharyngeal nerve exits the skull through the anteromedial aspect of the jugular foramen, anterior to the vagus and accessory nerve, and passes forward between the ICA and IJV. It lies posterior to the ICA deep in the styloid process and further in its course passes anterior to the ICA between the ICA and external carotid artery (ECA) (Figure 1) [6–9]. Thus, in the submandibular region, it lies posterior to the ICA. In recent years, ultrasound-guided nerve blocks for chronic pain have shown various advantages over landmark techniques; however, descriptions of ultrasound-guided glossopharyngeal nerve block (UGPNB) are scarce [8]. A case report in a patient with oral cancer described UGPNB by depositing phenol posterior to the ICA in the submandibular region, which is the anatomical location of the glossopharyngeal nerve, with good pain relief [9]. Figure 1 Open in new tabDownload slide Glossopharyngeal nerve posterior to the internal carotid artery in the submandibular region. Figure 1 Open in new tabDownload slide Glossopharyngeal nerve posterior to the internal carotid artery in the submandibular region. To the best of our knowledge, there are no randomized studies on UGPNB comparing it with the landmark technique. The hypothesis of the present study was that UGPNB performed by depositing local anesthetic posterior to the internal carotid artery in the submandibular region would result in superior pain control compared with the extraoral landmark technique. The primary objective of the present study was to compare the numerical rating scale (NRS) between patients given UGPNB and extraoral landmark GPNB at three weekly blocks and at follow-up one, three, and five weeks after the third block. A secondary objective was to compare quality of life by BPI scores, rescue medications, and satisfaction scores between the two groups in terms of the above timelines. As there is only one case report on UGPNB, the present study also determined that ultrasound probe (linear or curvilinear) best delineates the ICA and needle trajectory (in plane or out of plane) devoid of blood vessels to reach the posterior part of the ICA in the submandibular region to perform the block. Methods After institutional ethics committee approval and informed written consent, this prospective randomized, controlled, nonblinded study was conducted in the pain clinic of the Department of Anaesthesiology, Critical Care and Pain Medicine at All India Institute of Medical Sciences, New Delhi, between January 2015 and December 2018. Inclusion criteria were adult patients in the age group of 18–80 years with a diagnosis of unilateral Eagle syndrome and radiating ear pain. Exclusion criteria included patient refusal, known diabetes mellitus, ear and throat pathology, central nervous system pathology, local site infection, allergy to local anesthetics, sepsis, coagulopathy, behavioral abnormalities, and BMI >30. All patients diagnosed with Eagle syndrome in the Department of Otorhinology with a visual analog scale score >3 were referred to the pain clinic for further pain management [2]. Only patients with unilateral Eagle syndrome with ear pain on the affected side were recruited for the present study. All patients were given standard medical therapy of one oral tablet of pregabalin 75 mg once a day, oral tablet duloxetine 20 mg once a day, and one tablet of etoricoxib 120 mg once a day. With the above treatment, when the reported NRS was >5, patients were recruited and randomized to the study groups by a computer-generated random table. All recruited patients agreed to take part in the study. A total of 51 patients were recruited and divided into two groups; Group UGPNB (N = 25), where three UGPNBs at an interval of one week with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone were given, and Group GPNB (N = 26), where three landmark GPNBs at an interval of one week with similar drug as in Group UGPNB were given. Medical treatment was continued in all patients in both groups for the entire period of the study. All patients were given weekly GPNBs according to their assigned group for three consecutive weeks, and follow-up occurred at one week, three weeks, and five weeks after the third block. If a patient in either of the groups reported an NRS of >5 before the scheduled block or at follow-up, rescue medication with oral tramadol 50 mg once a day, up to a maximum of three times daily, was given. All blocks were given in the block area of the outpatient pain department (OPD) under strict aseptic precautions under standard monitoring of electrocardiogram (ECG), oxygen saturation (SPO2), and noninvasive blood pressure (NIBP). Intravenous access was obtained before the block was performed. For UGPNB, patients were laid supine with their neck turned to the opposite side (Figure 2). The ipsilateral neck of the patient was scanned using an ultrasonography machine (FUJIFI SonoSite Edge, Linear probe 13–6 MHz) from the base of the neck to look for the common carotid artery and IJV; position was confirmed by colored Doppler (Figure 2). The common carotid artery was traced upwards until bifurcation to the ICA and ECA was seen. The ICA after bifurcation lies posterior and deep to the ECA and was traced with the ultrasound probe upwards until the submandibular region between the mastoid process and the angle of the mandible was reached (Figure 3). If delineation of vessels was difficult with a low-frequency linear probe, a high-frequency curvilinear probe was used (FUJIFI SonoSite Edgelow frequency 2–5 MHz) and noted. The area posterior to the ICA and in the intended trajectory of the needle (in plane or out of plane) was scanned for presence of blood vessels by Doppler (Figure 3). The shortest distance to reach the posterior ICA devoid of blood vessels was selected as the final needle trajectory. In an out-of-plane needle trajectory, the needle was always passed from the Caudad side of the probe. In an in-plane needle trajectory, the needle was always passed from the posterior to anterior side. If vessels were found in both in-plane and out-of-plane trajectories to reach the posterior part of the ICA, the placement of the needle tip was protocolized to be placed at, in the following order: between the IJV and the ICA (as beyond the styloid process glossopharyngeal nerve lies between the IJV and the ICA); if not possible due to the presence of blood vessels in the needle trajectory, the needle was placed medial to the ICA; and if both were not possible due to the presence of vessels, the needle tip was directed above the ICA. A 26-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block without any prior local anesthesia (Figure 4). After the needle tip was placed at the desired location, aspiration for blood was done, and 0.1 mL of saline was injected to assess the spread. After this, 1.5 mL of 0.5% bupivacaine 7.5 mg with 20 mg of depomedrol (methylprednisolone injectable suspension) was injected, and the extension tubing was flushed with saline after the block. The spread of drug was confirmed in real time using ultrasound. The type of probe and needle trajectory were noted. Figure 2 Open in new tabDownload slide Head turned to the opposite side and initial scanning with linear probe, tracing the internal carotid artery from the base of the neck to the submandibular region. Figure 2 Open in new tabDownload slide Head turned to the opposite side and initial scanning with linear probe, tracing the internal carotid artery from the base of the neck to the submandibular region. Figure 3 Open in new tabDownload slide Twenty-six-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block. Figure 3 Open in new tabDownload slide Twenty-six-gauge, 3.5-cm hypodermic needle with 10-cm extension flushed with saline was used to perform the block. Figure 4 Open in new tabDownload slide Final scan with curvilinear probe in the submandibular region delineating internal carotid artery (ICA), external carotid artery, and internal jugular vein. The needle trajectory in this patient is out of plane toward the lateral part of the ICA for ultrasound-guided glossopharyngeal nerve block. Figure 4 Open in new tabDownload slide Final scan with curvilinear probe in the submandibular region delineating internal carotid artery (ICA), external carotid artery, and internal jugular vein. The needle trajectory in this patient is out of plane toward the lateral part of the ICA for ultrasound-guided glossopharyngeal nerve block. An extraoral approach by landmark technique was performed as previously described, and a similar amount of drug was injected [5]. NRS was assessed at all time points by a third observer who was blinded to the technique used. All patients were observed for a period of 30 minutes in the recovery area before discharge. NRS was noted before every block, 30 minutes after every block, and at one, three, and five weeks after the third block. Quality of life by Brief Pain Inventory [10] and satisfaction scores (0 = not satisfied and 10 = very much satisfied) were also noted at the above time intervals. Complications like hoarseness, facial palsy, blood on aspiration, and sympathetic blockade were noted. SS was involved in the conduct, acquisition of data, and analysis. JP was involved in planning, conduct, conception, design, and the final draft. Statistical Analysis A previous study compared NRS scores in patients who received medical therapy and GPNB using a landmark technique [1]. There was reduction in NRS scores from a baseline of 5 ± 0.8 to 2 ± 0.8 at the end of two months in the GPNB group. The sample size for this study was calculated considering the change in NRS scores in Group UGPNB from a baseline of 5 ± 0.8 to 2 ± 0.8 at two months and assuming a change of one unit more in Group GPNB compared with Group UGPNB, that is, four units from baseline in two months. To achieve 90% power with a 5% level of significance, we required 25 samples in each group. Statistical analysis was carried out using Stata 12.0 (StataCorp, College Station, TX, USA). Data are presented as number (percentage), mean ± SD, or median (minimum–maximum), as appropriate. Baseline continuous variables and categorical variables were compared between the groups using the unpaired t test/Wilcoxon rank-sum test and chi-square test/Fisher exact test, respectively. The primary outcome variable, NRS, was assessed for normality using the Shapiro-Wilks test. NRS scores over a period of time were analyzed using the Wilcoxon rank-sum test once the date did not follow a normal distribution. Quality of pain, assessed using the Brief Pain Questionnaire, was analyzed between the groups using the chi-square test for trend. Vital parameters over a period of time between the groups were assessed using the generalized estimating equation (GEE). Complications of three blocks were compared between the groups using the Fisher exact test. P values <0.05 were considered statistically significant. Results Both groups were comparable in demographics, duration of illness, length of styloid process, site of GPN, and duration of illness (Table 1). Table 1 Demographics and baseline disease parameters Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 1 Demographics and baseline disease parameters Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 Demographic Data . Group UGPNB . Group GPNB . P Value* . Age, y 42.1 ± 11.2 40.8 ± 11.26 0.678 Males 10 8 0.564 Females 15 18 0.668 Duration of illness, y 1.8 (0.5–5) 2.0 (1–4) 0.288 Site of pain  Right side 18 16 0.555  Left side 7 10 Length of styloid process  Right side, cm 3.16 ± 0.563 3.11 ± 0.54 0.76  Left side, cm 3.35 ± 0.23 3.40 ± 0.28 0.98 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab In intergroup analysis, baseline NRS was comparable between the groups (P = 0.548) (Table 2). NRS scores 30 minutes after every block were comparable between the groups (Table 3). However, a week after each block, NRS was significantly lower in Group UGPNB compared with Group GPNB (P = 0.011, P = 0.004, P = 0.034, respectively) (Table 2). NRS scores became comparable at three and five weeks after the third block (P = 0.136, P = 0.202, respectively) (Table 2). Table 2 NRS before first, second, and third blocks and at follow-up at weeks 6 and 8: Intergroup analysis NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. † NRS before block. ‡ NRS at follow-up. Open in new tab Table 2 NRS before first, second, and third blocks and at follow-up at weeks 6 and 8: Intergroup analysis NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 NRS . Group UGPNB Median (Min–Max) . Group GPNB Median (Min–Max) . P Value* . Baseline NRS before 1st block 7 (5–8) 7 (5–8) 0.548 Before 2nd block† 3 (1–6) 4 (3–6) 0.011* Before 3rd block† 2 (0–4) 4 (1–6) 0.004* 1 wk after 3rd block‡ 2 (0–5) 3 (1–8) 0.034* 3 wk after 3rd block‡ 2 (0–6) 3 (0–8) 0.136 5 wk after 3rd block‡ 3 (0–6) 3 (0–8) 0.202 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. † NRS before block. ‡ NRS at follow-up. Open in new tab Table 3 NRS 30 minutes after block: Intergroup analysis NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 3 NRS 30 minutes after block: Intergroup analysis NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 NRS 30 Min After Block . Group UGPNB . Group GPNB . P Value* . 1st block 2 (0–4) 2 (0–4) 0.524 2nd block 1.5 (0–4) 1.5 (0–3) 0.296 3rd block 1 (0–3) 1.5 (0–4) 0.278 GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab In intragroup analysis, at each block, NRS scores 30 minutes postblock were significantly lower than preblock NRS scores in both groups (P < 0.001) (Table 4). In both groups, at each time frame NRS scores were lower than baseline NRS scores (P < 0.001); however, the average NRS score was >3 before the second and third blocks in Group GPNB (Table 5). Rescue medications were not required by any patients in either group. Table 4 NRS before and 30 minutes after the block: Intragroup analysis Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 4 NRS before and 30 minutes after the block: Intragroup analysis Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* Time of Assessment . Group UGPNB . Group GPNB . NRS Before Block . NRS After Block . P Value* . NRS Before Block . NRS After Block . P Value* . 1st block 7 (5–8) 2 (0–4) <0.001* 7 (5–8) 2 (0–4) <0.001* 2nd block 3 (1–6) 1.5 (0–4) <0.001* 4 (3–6) 1.5 (0–3) <0.001* 3rd block 2 (0–4) 1 (0–3) <0.001* 4 (1–6) 1.5 (0–4) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 5 Baseline NRS vs NRS at follow-up: Intragroup analysis Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 5 Baseline NRS vs NRS at follow-up: Intragroup analysis Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* Group UGPNB . Group GPNB . Baseline NRS . Follow-up . NRS Before Block . P Value* . Baseline NRS . Follow-up . NRS Before Block . P Value* . 7 (5–8) Before 2nd block 3 (1–6) <0.001* 7 (5–8) Before 2nd block 4 (3–6) <0.001* Before 3rd block 2 (0–4) <0.001* Before 3rd block 4 (1–6) <0.001* 1 wk after 3rd block 2 (0–5) <0.001* 1 wk after 3rd block 3 (1–8) <0.001* 3 wk after 3rd block 2 (0–6) <0.001* 3 wk after 3rd block 3 (0–8) <0.001* 5 wk after 3rd block 3 (0–6) <0.001* 5 wk after 3rd block 3 (0–8) <0.001* GPNB = landmark glossopharyngeal nerve block; NRS = numerical rating scale; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Comparison of quality of life by BPI revealed a significant reduction in average pain intensity from mild pain to no pain in Group UGPNB at the second, third, and fourth weeks after the third block compared with Group GPNB (P = 0.002, P = 0.002, P = 0.035, respectively). There was a significant reduction in right now pain intensity from moderate to mild pain in Group UGPNB compared with Group GPNB at week 3 (P = 0.007) and a significant reduction in pain relief in Group UGPNB at the second visit vs Group GPNB (P = 0.023) when compared with the first visit. Least pain and worst pain were comparable at eight weeks. There was a significant reduction from mild interference to no interference in general activity in Group UGPNB at the second and third visits compared with Group GPNB (P = 0.017, P = 0.004, respectively). Mood was significantly better, from mild interference to no interference in Group UGPNB compared with Group GPNB at the second and third weeks (P = 0.037, P = 0.023, respectively). All other parameters were comparable. Satisfaction scores at week 2 were significantly higher in Group UGPNB (P = 0.010) (Table 6). Table 6 Satisfaction scores at each visit Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 GPNB = landmark glossopharyngeal nerve block; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Table 6 Satisfaction scores at each visit Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 Satisfaction Score . Group UGPNB . Group GPNB . P Value* . 1st wk 1.12 ± 0.33 1.11 ± 0.32 0.976 2nd wk 7.37 ± 1.34 6.48 ± 1.00 0.010* 3rd wk 8.04 ± 1.60 7.2 ± 1.35 0.052 4th wk 8.29 ± 1.6 7.84 ± 1.54 0.336 6th wk 7.83 ± 2.09 7.84 ± 1.84 0.957 8th wk 7.66 ± 2.29 7.32 ± 2.26 0.616 GPNB = landmark glossopharyngeal nerve block; UGPNB = ultrasound-guided glossopharyngeal nerve block. * P < 0.05, statistically significant. Open in new tab Probe and Needle Trajectory to Perform UGPNB In 68% of patients, a curvilinear probe was used to delineate the ICA (Table 7). Out-of-plane needle trajectory was required in 64% of patients to perform the block (Table 8). In 56% of patients the needle tip was placed posterior to the ICA, in 16% of patients the needle tip was placed superior to the ICA, in 20% of patients the needle tip was placed medial to the ICA, and in the remaining 8% of patients the needle tip was placed between the ICA and IJV (Table 9). Table 7 Type of ultrasound probe used Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 7 Type of ultrasound probe used Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) Probe . Group UGPNB, No. (%) . Linear probe 8 (32) Curvilinear 17 (68) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 8 Needle trajectory in the UGPNB group Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 8 Needle trajectory in the UGPNB group Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) Technique Used . Total No. of Patients (N = 25) (%) . In plane 9 (36) Out of plane 16 (64) UGPNB = ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 9 Needle tip position with respect to the internal carotid artery Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) ICA = internal carotid artery; IJV = internal jugular vein. Open in new tab Table 9 Needle tip position with respect to the internal carotid artery Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) Probe position . No. of Patients (%) . Superior to ICA 4 (16) Between ICA and IJV 2 (8) Posterior to ICA 14 (56) Anterior to ICA 5 (20) ICA = internal carotid artery; IJV = internal jugular vein. Open in new tab In Group UGPNB, when a block was performed with the needle tip posterior to the ICA, hoarseness was seen in 28% of patients during the first block, 14.3% during the second block, and in 14.3% patients during the third block. None of the patients had facial palsy. When the needle tip was anterior to the ICA, hoarseness was seen in 40% of patients during the first block, 40% of patients during the second block, and 20% of patients during the third block. None of the patients had facial palsy. When the needle tip was between the ICA and IJV, hoarseness was seen in 100% of patients during the first, second, and third blocks. None of the patients had facial palsy. When the needle tip position was above the ICA, one of the patients had hoarseness, but 50% of patients had facial palsy (Table 10). Thus, hoarseness was seen maximally when the needle tip was between the ICA and IJV and facial palsy was seen maximally when the needle tip was placed superior to the ICA. Complications of hoarseness and facial palsy were comparable between the groups (P = 0.68). NRS >3 was not seen in any patients when the needle was placed posterior to the ICA and was seen maximally in patients when the needle was placed superior to the ICA (Table 10). Complications like hematoma, intraocular injection, arrhythmias, and syncope were not seen in any patient in either group. Table 10 Complications in the UGPNB group with different needle tip positions at each block Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 ICA = internal carotid artery; IJV = internal jugular vein; NRS = numerical rating scale; UGPNB =ultrasound-guided glossopharyngeal nerve block. Open in new tab Table 10 Complications in the UGPNB group with different needle tip positions at each block Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 Needle Position (No. of Patients) . Hoarseness, No. (%) . Facial Palsy, No. (%) . NRS > 3 . 1st Block . 2nd Block . 3rd Block . 1st Block . 2nd Block . 3rd Block . Posterior to ICA (14) 4 (28) 2 (14.3) 2 (14.3) Nil Nil Nil 0 Medial to ICA (5) 2 (40) 2 (40) 1 (20) Nil Nil Nil 1 B/w ICA and IJV (2) 2 (100) 2 (100) 2 (100) Nil Nil Nil 1 Superior to ICA (4) Nil Nil Nil 2 (50) Nil Nil 2 ICA = internal carotid artery; IJV = internal jugular vein; NRS = numerical rating scale; UGPNB =ultrasound-guided glossopharyngeal nerve block. Open in new tab Discussion Three consecutive weekly UGPNBs for Eagle syndrome, performed by deposition of 1.5 mL of ropivacaine and dexamethasone posterior to the ICA in the submandibular region, resulted in significant pain reduction for at least a week after each block compared with the extraoral landmark technique. For UGPNB, in more than half of the patients, a curved low-frequency ultrasound probe and out-of-plane needle trajectory were most suitable to avoid vessels in the needle trajectory. For management of glossopharyngeal neuralgia, combining GPNB with medical therapy is better than medical therapy alone [4]. However, UGPNB has not been extensively studied or evaluated in the treatment of GPN. A single case report by Bedder et al. in 1985 described UGPNB in a patient with carcinoma of the tongue who had severe pain in the distribution of the glossopharyngeal nerve. The author used the ICA as a landmark and performed UGPNB with a 7.5-MHz imaging transducer coupled with a 5-MHz doppler transducer kept below the mastoid process and tilted caudally to visualize the ICA. Block was performed with a short-bevel 22-G short needle via an in-plane technique with 2.5 mL of neurolytic agent, and 100% alcohol was injected posterior to the ICA with very good pain relief and no complications [9]. Recently Azman et al. described UGPNB in cadavers, where the nerve was traced distally at the level of the middle constrictor muscle superficial to the anteroposterior pharyngeal wall where the hyoid bone was identified. Though the authors couldn’t visualize GPN on ultrasound, UGPNB was proposed by depositing local anesthetic into the distal parapharyngeal space. The authors sensed that distal block would be safer, as it is away from vital structures like the carotid, vagus, spinal accessory, and hypoglossal [11]. As this block was performed after a proximal contribution of the auricular branch of the vagus nerve to the glossopharyngeal nerve, it probably would not be effective in the patients recruited in the present study who presented with GPN with auricular symptoms. Further studies in patients with GPN without auricular symptoms with the distal block as described by Azman et al. are suggested [11]. Maher et al. performed UGPNB in a patient with Eagle syndrome using a peristyloid approach. They scanned the neck using a linear probe and located the styloid process, mastoid process, and mandible and then injected local anesthetic around it, following which the patient had good pain relief [6]. However, the styloid process might not always be visible in all patients, as some cases of Eagle syndrome are secondary to calcification of the stylohyoid ligament, rather than ossification making identification of the styloid process difficult. Anatomically the glossopharyngeal nerve is a very small nerve and is not visible on ultrasound. Thus, in the present study, pulsations of the ICA were taken as a landmark for UGPNB, as pulsations are clearly visible on ultrasound and vessels can also be confirmed with doppler. Fluoroscopy techniques have recently been used for glossopharyngeal neuralgia; however, this requires a special area to perform the block and thus has its limitations [12]. Similarly, percutaneous radiofrequency thermocoagulation after confirmation of sensory stimulation of the glossopharyngeal nerve has been found to be effective for long-term pain relief; however, all these techniques require a prescanning with fluoroscopy, which again requires a specialized area to perform the block [13]. The advantage of the present ultrasound technique is that there is no requirement of a specialized area to perform the block and the proposed UGPNB can easily be performed in the OPD. The above procedures require a needle size of at least 22 G, which might be uncomfortable for the patient. Use of a 26-G needle in the proposed block does not require another needle prick for prior local anesthesia before the block and is well tolerated by the patients. Both techniques in the present study are essentially field blocks, as the nerve was neither visualized nor localized by other techniques. We feel that similar pain relief at 30 minutes postblock points to the field effect; however, a longer effect of UGPNB compared with the landmark technique points to closer deposition of drug to the nerve when the ICA is taken as a landmark on ultrasound. Further studies with prior confirmation of GPN by sensory stimulation and with a smaller volume of drug are recommended. Limitations of the present study were inability to comment on anatomic variation of the glossopharyngeal nerve due to nonvisibility of the glossopharyngeal nerve on ultrasound. However, favorable results point to close location of the glossopharyngeal nerve to the ICA and thus effectiveness of the present approach. This study was not powered to comment on the superiority of various needle to positions with respect to ICA. Further cadaver studies in this regard are proposed. Another limitation was that the patient and the operator were not blinded; however, NRS was recorded by a third observer who was blinded to the procedure. Self-remitting hoarseness occurred maximally when the needle tip was placed between the ICA and the IJV, and self-remitting facial palsy occurred maximally when the needle was superficial to the ICA, probably due to the superficial location of the facial nerve. Pain relief was maximal when the needle tip was posterior to the ICA, and the least pain relief was seen when the needle tip was between the ICA and IJV. However, the present study is underpowered to determine complications and pain relief with different needle positions. The use of a curvilinear probe delineated the vessels better in the present study; however, further studies with a low-frequency probe with a smaller footprint are recommended. There was significant improvement in mood, average pain, and general activity in Group UGPNB in the weeks that the block was given, probably because of better pain relief with the ultrasound technique. To conclude, UGPNB with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone injected posterior to the ICA in the submandibular region provides better pain relief for at least a week compared with an extraoral landmark technique when three weekly consecutive blocks are given. However, NRS is comparable at three and five weeks after the third block. Mood and general activity are better with UGPNB. In most patients, a curvilinear probe and out-of-plane needle trajectory are most suitable for the ultrasound block. Funding sources: No funding. Conflicts of interest: None. References 1 Singh PM , Kaur M, Trikha A. An uncommonly common: Glossopharyngeal neuralgia . Ann Indian Acad Neurol 2013 ; 16 ( 1 ): 1 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 2 Raina D , Gothi R, Rajan S. Eagle syndrome . Indian J Radiol Imaging 2009 ; 19 ( 2 ): 107 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 3 Moulin D , Boulanger A, Clark A, et al. . Pharmacological management of chronic neuropathic pain: Revised consensus statement from the Canadian Pain Society . Pain Res Manag 2014 ; 19 ( 6 ): 328 – 35 . Google Scholar Crossref Search ADS PubMed WorldCat 4 Dworkin RH , O’Connor AB, Backonja M, et al. . Pharmacologic management of neuropathic pain: Evidence-based recommendations . Pain 2007 ; 132 ( 3 ): 237 – 51 . Google Scholar Crossref Search ADS PubMed WorldCat 5 Singh PM , Dehran M, Mohan VK, Trikha A, Kaur M. Analgesic efficacy and safety of medical therapy alone vs combined medical therapy and extraoral glossopharyngeal nerve block in glossopharyngeal neuralgia . Pain Med 2013 ; 14 ( 1 ): 93 – 102 . Google Scholar Crossref Search ADS PubMed WorldCat 6 Maher T , Shankar H. Ultrasound-guided peristyloid steroid injection for Eagle syndrome . Pain Pract 2017 ; 17 ( 4 ): 554 – 7 . Google Scholar Crossref Search ADS PubMed WorldCat 7 Pintaric TS. Upper airway blocks for awake difficult airway management . Acta Clin Croat 2016 ; 55(Suppl 1 ): 85 – 9 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 8 Barrington MJ , Uda Y. Did ultrasound fulfill the promise of safety in regional anesthesia? Curr Opin Anaesthesiol 2018 ; 31 ( 5 ): 649 – 55 . Google Scholar Crossref Search ADS PubMed WorldCat 9 Bedder MD , Lindsay D. Glossopharyngeal nerve block using ultrasound guidance: A case report of a new technique . Reg Anesth 1989 ; 14 ( 6 ): 304 – 7 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 10 Cleeland CS , Ryan KM. Pain assessment: Global use of the Brief Pain Inventory . Ann Acad Med Singapore 1994 ; 23 ( 2 ): 129 – 38 . Google Scholar PubMed OpenURL Placeholder Text WorldCat 11 Ažman J , Stopar Pintaric T, Cvetko E, Vlassakov K. Ultrasound-guided glossopharyngeal nerve block: A cadaver and a volunteer sonoanatomy study . Reg Anesth Pain Med 2017 ; 42 ( 2 ): 252 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 12 Telischak NA , Heit JJ, Campos LW, Choudhri OA, Do HM, Qian X. Fluoroscopic C-arm and CT-guided selective radiofrequency ablation for trigeminal and glossopharyngeal facial pain syndromes . Pain Med 2018 ; 19 ( 1 ): 130 – 41 . Google Scholar Crossref Search ADS PubMed WorldCat 13 Song L , He L, Pei Q, et al. . CT-guided percutaneous radiofrequency thermocoagulation for glossopharyngeal neuralgia: A retrospective clinical study of 117 cases . Clin Neurol Neurosurg 2019 ; 178 : 42 – 5 . Google Scholar Crossref Search ADS PubMed WorldCat © 2020 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

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Pain MedicineOxford University Press

Published: Jun 1, 2020

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