Effect of Ultrasound Guided Bilateral Greater Occipital Nerve Block on Serum Calcitonin Gene Related Peptide (CGRP) in Chronic Migraine

Background: The trigeminal ganglion plays a key role in primary headache pathophysiology. Calcitonin gene-related peptide (CGRP) and CGRP receptors are expressed in trigeminal neurons that form C-fibers and A-fibers, respectively. In migraine attacks, there is release of CGRP into the cranial venous outflow, in refractory headache to conventional pharmacologic management, minimally invasive techniques such as greater occipital nerve block (GONB) are feasible for pain relief, and help to decrease the frequency of the attacks, Studies on the ultrasound (US) guided GON injection technique have emphasized that this technique has a higher success rate and should allow for a more precise block of the nerve. Our study will be concerned by correlation of CGRP level as a biomarker for effectiveness and responders of us guided GON block in chronic migraine (CM). Methods: twenty patients diagnosed with chronic migraine were recruited in this study. All participants underwent ultrasound-guided bilat. GONB by 40 mg triamcinolone and 1 cc leidocaine using a portable ultrasound system with a 7 – 13 MHz multifrequency transducer, blood samples were collected from antecubital vein immediately before and three to five weeks after injection clinical response was evaluated using headache diaries Results: CGRP levels after ultrasound guided GONB (median, 40 pg/mL; range, 25-60) were significantly lower as compared with CGRP levels obtained before GONB (median, 145 pg/mL; range, 60-380; P =0.001). Pretreatment CGRP levels in non-responders (310 pg/mL) were significantly higher than those seen in responders being in poor responders less than 50% improvement (135 pg/ml) and good responders (140 pg/mL; P = 0.003). One month after treatment. A number of demographic factors, clinical features, and comorbidities were not different in responders as compared with those of nonresponders. Conclusion: These results suggests that interictal CGRP levels can be of help in predicting the response to GONB and suggest that the mechanism of action of GONB in CM is the reversal of sensitization as a result of the inhibition of CGRP release still more studies needed to highlight CGRP role with GONB

Preventive effect of greater occipital nerve block on patients with episodic migraine: A randomized double‐blind placebo‐controlled clinical trial

Objective Since the data regarding the efficacy of greater occipital in episodic migraines are rare, we aimed to examine the efficacy of greater occipital block in the prophylaxis of episodic migraines without aura and compare different injectable drug regimens. Methods In a randomized, double-blind placebo-controlled trial, adult patients suffering from episodic migraines without aura were randomized to one of the following: triamcinolone, lidocaine, triamcinolone plus lidocaine, and saline. Patients were assessed at baseline, one week, two weeks, and four weeks after the injection for severity and duration of headaches and side effects. Results Fifty-five patients completed the study. Repeated measures ANOVA indicated that the severity and duration decreased significantly after the greater occipital block (P < 0.001, P = 0.001 respectively) in all four groups. However, there was no difference between groups at any study time points (P > 0.05). In paired sample T-test, only groups 2 and 3 with lidocaine as a part of the injection showed a significant decrease in frequency compared to the baseline (P = 0.002, P = 0.019). Three patients reported side effects with a possible association with triamcinolone. Conclusion Greater occipital block with a local anesthetic significantly decreases the number of attacks in episodic migraine, whereas no injection was superior to the placebo in regards to the duration and severity of the headaches. Trial Registration Information: Iranian Registry of Clinical Trials (IRCT). Registration number: IRCT2017070334879N1. https://www.irct.ir/trial/26537 .

Greater occipital nerve block modulates nociceptive signals within the trigeminocervical complex

IntroductionThe pharmacological block of the greater occipital nerve has been proven effective in numerous headache and facial pain syndromes. This clinical effect supports the hypothesis of a strong functional interaction between the occipital and trigeminal nerves which has been proposed in neurophysiological in vivo experiments in rodents. Although it is likely that the interaction has to occur in the central nervous system, the exact site and the mechanisms of the interaction remain largely unknown.MethodsFocusing on these questions we investigated in a double-blind, placebo-controlled, randomised study the influence of an occipital nerve block with lidocaine 1% on neuronal activation in the trigeminocervical complex using high-resolution functional magnetic resonance on a 3T scanner. In order to investigate potential clinical effects on the trigeminal nerve, we further performed quantitative sensory testing and analysed a potential shift in thermal detection and pain thresholds.ResultsThe pharmacological block of the greater occipital nerve induced an occipital anaesthesia ipsilateral to the block. Functional imaging revealed that the occipital injection of lidocaine but not placebo significantly reduced nociceptive trigeminal activation.ConclusionsThese data suggest that the functional inhibition of the occipital nerve block on trigeminal nociceptive activity is likely to occur at the C2 level where the occipital nerve enters the trigeminocervical complex and converges on the same central nuclei before the signal crosses the midline at that level and is then transmitted to higher processing centres.

THE EFFICACY OF GREATER OCCIPITAL NERVE BLOCK IN PATIENTS WITH CHRONIC MIGRAINE

Background and Purpose: In chronic migraines(CM), the rate of benefiting from medical treatment is relatively low, and it is known that patients use analgesics extensively. Greater occipital nerve (GON) block, have been started to be used in chronic migraine patients who were refractory to treatment. In this study, we aimed to evaluate the headache attack frequency, analgesic use, VAS (Visual Analog Scale) and MIDAS (Migraine Disability Assessment Scale) scores in the 3-month follow-up of patients we had performed a GON block in our clinic for chronic migraine refractory to medical treatment. Methods: A total of 120 CM patients were included in the study. The number of analgesics used, the number of days with pain, and the VAS and MIDAS scores were recorded before the GON block and at one and three months of treatment. Results: There was a statistically significant (p<0.001*) reduction in the number of days with pain, analgesic use, and the VAS and MIDAS scores in the first and third months compared to the pre-treatment baseline values in patients who had undergone a GON block. No significant differences between the first and third months. Conclusions: After the GON block, we noted a significant reduction of headaches and improved quality of life in patients who had been experiencing severe headaches despite medical treatment. The GON block has an exceptionally high benefit rate, might be considered as a treatment option before migraines gain chronicity, patients are not exposed to an excessive medical burden and increased treatment costs. Keywords: Headache; Chronic migraine; Greater occipital nerve block.