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

Postural physiotherapy for cervicogenic headache after occipital nerve block: a retrospective study

Cervicogenic headache has a complex and poorly understood pathophysiology. Symptoms are typical and involve the C2 and C3 nerve roots. There are no specific recommendations for physical therapy, although occipital nerve block is a known pharmacological treatment. Some evidence suggests that hip rotation correction could aid in reducing cervical pain symptoms. The objective of this work is to evaluated the role of postural physiotherapy for hip rotation correction using the Maitland technique in patients with cervicogenic headache who underwent an occipital nerve block. In this retrospective, observational and uncontrolled study, patients were evaluated from January 2017 to February 2018. After diagnosis of cervicogenic headache they underwent anesthetic block, hip radiography with lower limb scanometry and cervical tomography, after which they were referred to physical therapy. The analog pain scale was used for evaluation at the time of diagnosis and after the proposed physiotherapy. Patients submitted to an occipital nerve block were divided into three groups: Group I (n = 15, physical therapy with Maitland technique) had an analog pain score of 1.6 after the physical therapy, Group II (n = 11, conventional physiotherapy) had an analog pain score of 3.7 after the physical therapy and Group III (n = 13, occipital nerve block only) had an analog pain score of 5.2 after the occipital nerve block. The results suggest that an occipital nerve block in combination with the Maitland technique is superior in patients with cervicogenic headache compared to nerve block only or blockade combined with non-specific physical therapy (p=0,013).

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.