The Potential Roles of Cervical Plexus Abnormalities in Occipital Neuralgia: An Anatomic Variant Explored

Occipital neuralgia (ON) is a condition defined as a headache characterized by paroxysmal burning and stabbing pain located in the distribution of the greater occipital nerve (GON), lesser occipital nerve (LON), or third occipital nerves (TON). This condition can be severely impairing in symptomatic patients and is known to have numerous etiologies deriving from various origins such as trauma, anatomical abnormalities, tumors, infections, and degenerative changes. This study reports four cases of a previously undescribed anatomical variant in which the (spinal) accessory nerve (SAN) fuses with the LON before piercing the sternocleidomastoid (SCM). The fusion of these two nerves and their route through the SCM points to a potential location for nerve compression within the SCM and, in turn, another potential source of ON. This anatomical presentation has clinical significance as it provides clinicians with another possible cause of ON to consider when diagnosing patients who present with complaints of a headache. Additionally, this study explores the prevalence of piercing anatomy of the LON and GAN and discusses their clinical implications.

Decompression of the Greater Occipital Nerve for Occipital Neuralgia and Chronic Occipital Headache Caused by Entrapment of the Greater Occipital Nerve

Background Chronic entrapment of the greater occipital nerve (GON) can not only manifest in typical stabbing pain of occipital neuralgia (ON) but also lead to continuous ache and pressure-like pain in the occipital and temporal areas. However, the effect of GON decompression on these symptoms has yet to be established. We report the follow-up results of GON decompression in typical cases of ON and chronic occipital headache due to GON entrapment (COHGONE). Methods A 1-year follow-up study of GON decompression was conducted on 11 patients with typical ON and 39 COHGONE patients with GON entrapment. The degree of pain reduction was analyzed using the numerical rating scale-11 (NRS-11) score and percent pain relief before and 1 year after surgery. A success was defined by at least a 50% reduction in pain measured via NRS-11 during the 12-month follow-up. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Postoperative outcome was also evaluated using the Barrow Neurological Institute (BNI) pain intensity score. The difference in GON decompression between the patients with typical ON and those with COHGONE was studied. Results GON decompression was successful in 43 of 50 patients (86.0%) and percent pain relief was 72.99 ± 25.53. Subjective improvement based on a 10-point Likert scale was 7.9 ± 2.42 and the BNI grade was 2.06 ± 1.04. It was effective in both the ON and COHGONE groups, but the success rate was higher in the ON group (90.9%) than in the COHGONE group (84.6%), showing statistically significant differences in the results based on average NRS-11 score, percent pain relief, subjective improvement, and BNI grades (p < 0.05, independent t-test). Conclusion GON decompression is effective in chronic occipital headache and in ON symptoms induced by GON entrapment.

Greater occipital nerve blockade using ultrasound guidance for the headache of spontaneous intracranial hypotension - A case report -

BackgroundSpontaneous intracranial hypotension occurs due to cerebrospinal fluid leakage from the spinal column, and orthostatic headache is the most common clinical presentation. Recent studies showed that bilateral greater occipital nerve blockade demonstrated clinical efficacy in relieving post-dural puncture headache after caesarean section. CaseA 40-year-old male who presented severe orthostatic headache was consulted to our pain clinic from neurology department. He initially felt a dull nature pain over the whole occipital area which then spread over the frontal and parietal areas. His headache was combined with nausea and vomiting. An epidural blood patch was delayed until final cisternography, and bilateral greater occipital nerve blockade using ultrasound guidance was performed instead. After the blockade, the previously existing headache around the occipital and parietal areas disappeared completely, but mild headache persisted around the frontal area.ConclusionsGreater occipital nerve blockade could be a good therapeutic alternative to improve headache resulting from spontaneous intracranial hypotension.

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

Neurostimulation Treatment in Chronic Cluster Headache—a Narrative Review

Purpose of Review In this narrative review, the current literature on neurostimulation methods in the treatment of chronic cluster headache is evaluated. These neurostimulation methods include deep brain stimulation, vagus nerve stimulation, greater occipital nerve stimulation, sphenopalatine ganglion stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, supraorbital nerve stimulation, and cervical spinal cord stimulation. Recent Findings Altogether, only nVNS and SPG stimulation are supported by at least one positive sham-controlled clinical trial for preventive and acute attack (only SPG stimulation) treatment. Other clinical trials either did not control at all or controlled by differences in the stimulation technique itself but not by a sham-control. Case series report higher responder rates. Summary The evidence for these neurostimulation methods in the treatment of chronic cluster headache is poor and in part contradictive. However, except deep brain stimulation, tolerability and safety of these methods are good so that in refractory situations application might be justified in individual cases.

Great occipital nerve long-acting steroid injections in cluster headache therapy: an observational prospective study

Background Injections targeting the occipital nerve are used to reduce headache attacks and abort cluster bouts in cluster headache patients. There is no widely accepted agreement over the optimal technique of injection, type and doses of steroids and/or anesthetics to use, as well as injection regimens. The aim of this study was to verify the effectiveness and safety of greater occipital nerve long-acting steroid injections in the management of episodic and chronic cluster headache. Methods We conducted a prospective observational cohort study on episodic (ECH) and chronic cluster headache patients (CCH). ECH were included in the study at the beginning of a cluster period. Three injections with 60 mg methylprednisolone were performed on alternate days. We registered the frequency and intensity of attacks three days before and 3, 7 and 30 days after the treatment, the latency of cluster relapse, adverse events, scores evaluating anxiety (Zung scale), depression (Beck’s Depression Scale) and quality of life (Disability Assessment Schedule II, 12-Item Self-Administered Version). Primary outcome was the interruption of the cluster after the three injections. Responders conducted a follow-up period of 12 months. Results We enrolled 60 patients, 47 with ECH and 13 with CCH. We observed a complete response in 47.8% (22/46) of episodic and 33.3% (4/12) of chronic patients. Moreover, a partial response (reduction of at least 50% of attacks) was obtained in further 10.8% (5/46) of episodic and in 33.3% (4/12) of chronic patients at 1 month. Median pain-free period was of 3 months for CCH responders. Only mild adverse events were reported in 38.3% (23/58) cases. Conclusions We suggest three greater occipital nerve injections of 60 mg methylprednisolone on alternate days as useful therapy in episodic and chronic cluster headache. This leads to a long pain-free period in chronic forms. Adverse effects are mild and support its use as first choice. Trial registration The study was inserted in AIFA observational studies register.

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 .