Referred pain after painful stimulation of the greater occipital nerve in humans: evidence of convergence of cervical afferences on trigeminal nuclei

A new neuromodulation method in chronic migraine; non-ınvasive pulsed radiofrequency, a single-blinded, randomised, controlled trial

OBJECTIVE

Non-invasive pulsed radiofrequency (NipRF) therapy, a neuromodulation method for peripheral nerves, is a new treatment modality for pain. We aimed to show the changes in pain severity and frequency per month in chronic migraine with NipRF treatment.

METHODS

We treated patients diagnosed with chronic migraine according to the International Classification of Headache Disorders III beta diagnostic criteria. In half of the patients, we applied pulsed radiofrequency (pRF) treatment with transcutaneous electrodes to the greater occipital nerve (GON) trace. In the other half, we applied the GON block under ultrasound guidance. The Migraine Disability Assessment Scale (MIDAS) was administered to the participants, and those with scores > 2 were included in the study. Pain intensity and frequency were evaluated using the visual analog scale (VAS) and a headache diary completed before and 4 weeks after treatment.

RESULTS

When both groups were compared, the pre- and post-treatment VAS scores and headache frequencies were similar. Comparing the pre-treatment and post-treatment values within the groups, VAS scores and headache frequency decreased significantly after treatment in both groups (p < 0.001).

CONCLUSION

In this study, we observed that NipRF treatment is safe and effective for treating chronic migraine. Pain intensity and frequency decreased with NipRF treatment, similar to that in the GON block group.

CLINICAL TRIALS REGISTRATION NUMBER

NCT05499689, Date: 08/11/2022.

The effect of greater occipital nerve block on amplification of somatic symptoms and anxiety and depression levels in chronic migraine

OBJECTIVES

It is known that chronic migraine (CM) is often accompanied by anxiety, depression, and psychosomatic complaints. We designed this study with the assumption that greater occipital nerve (GON) block treatment could potentially improve not only pain symptoms but also psychosomatic complaints. This study aimed to evaluate the changes in the visual analog scale (VAS), somatosensory amplification scale (SSAS), beck depression ınventory (BDI), and beck anxiety ınventory (BAI) with GON block treatment in patients with CM.

METHODS

This study was conducted retrospectively on 164 patients with CM between December 2018 and January 2023. Patients underwent six sessions of GON block treatment at weeks 0, 1, 2, 3, 5, and 7. VAS, SSAS, BAI, and BDI scores; number of attacks per month (NAM); attack pain duration (APD); and monthly use of analgesics (UA) were compared before the start and at week 8 of GON block treatment.

RESULTS

The mean age of the subjects was 38 ± 9 years. Statistical analysis revealed that VAS, SSAS, BAI, and BDI scores; NAM; APD; and monthly UA were statistically significantly lower following GON block treatment than before GON block treatment (p < 0.001 each).

CONCLUSION

GON block treatment was effective for pain and somatic complaints (amplification of physical symptoms), anxiety, and depressive symptoms accompanying CM in patients with CM.

Comparison of Greater Occipital Nerve Blockade and Sphenopalatine Ganglion Blockade in Patients with Episodic Migraine

Objectives: Compare the effects of greater occipital nerve (GON) and sphenopalatine ganglion (SPG) blocks on headache intensity and duration, number of headache days, and disability in patients with episodic migraine. Methods: In this prospective single-blind randomized study, patients with episodic migraine were randomly divided into two groups: GON and SPG block groups. Patients received blocks once a week for 4 weeks, and once a month for 2 months. The number of headache days, the headache duration, numeric rating scale (NRS) scores, and number of acute medical treatments were assessed before the procedures and 1 month, 2 months, and 3 months after the procedures. Disability was evaluated using the migraine disability assessment (MIDAS) questionnaire at baseline and 3 months after treatment. This study protocol is registered at ClinicalTrials.gov (NCT06243874.). Results: 19 patients in the GON block group and 18 patients in the SPG block group were evaluated. Significant improvements in pain severity, headache duration, number of headache days, and the need for acute medical treatment were observed in the 1st, 2nd, and 3rd months compared to baseline in the two groups (p < 0.001). There were significant improvements in the MIDAS scores in the third month (p < 0.001). The GON block group showed a greater reduction in headache intensity, duration, number of headache days, and MIDAS scores compared to the SPG block group in the 3rd month (p < 0.001). Conclusions: GON block reduces headache duration, intensity, the number of headache days, and the need for acute medical treatment much more than SPG block in patients with episodic migraine.

Cervicogenic Headaches: A Literature Review and Proposed Multifaceted Approach to Diagnosis and Management

Cervicogenic headaches are a secondary headache disorder attributable to cervical spine dysfunction resulting in head pain with or without neck pain. Diagnosis of this condition has been complicated by varied clinical presentations, causations, and differing diagnostic criteria. In this article, we aim to clarify the approach to diagnosing cervicogenic headaches by providing an overview of cervicogenic headaches, clinical case examples, and a practical diagnostic algorithm based on the most current criteria. A standardized approach will aid in confirmation of the diagnosis of cervicogenic headaches and facilitate further research into this condition.

Neuralgia in the occipital region associated with ipsilateral trigeminal herpes zoster: Three case reports

BACKGROUND

Nerve fibers related to pain and temperature sensation in the trigeminal nerve territory converge with the upper cervical spinal nerves from the level of the lower medulla oblongata to the upper cervical cord. This structure is called the trigemino-cervical complex and may cause referred pain in the territory of the trigeminal or upper cervical spinal nerves.

CASE SERIES

Here, we report three cases of paroxysmal neuralgia in the occipital region with mild conjunctivitis or a few reddish spots in the ipsilateral trigeminal nerve territory. The patients exhibited gradual progression of these reddish spots evolving into vesicles over the course of several days, despite the absence of a rash in the occipital region. The patients were diagnosed with trigeminal herpes zoster and subsequently received antiherpetic therapy. Remarkably, the neuralgia in the occipital region showed gradual amelioration or complete resolution before the treatment, with no sequelae reported in the occipital region.

DISCUSSION

The trigemino-cervical complex has the potential to cause neuralgia in the occipital region, as referred pain, caused by trigeminal herpes zoster. These cases suggest that, even if conjunctivitis or reddish spots appear to be trivial in the trigeminal nerve territory, trigeminal herpes zoster should be considered when neuralgia occurs in the ipsilateral occipital region.

Evidence for chronic headaches induced by pathological changes of myodural bridge complex

Clinical studies have shown that there may be a certain relationship between pathological changes of the myodural bridge complex (MDBC) and chronic headaches of unknown cause. But there is still a lack of experimental evidence to explain the possible mechanism. This study aims to further confirm this relationship between MDBC and chronic headaches and explore its potential occurrence mechanism in rats. Bleomycin (BLM) or phosphate-buffered saline (PBS) was injected into the myodural bridge fibers of rats to establish the hyperplastic model of MDBC. After 4 weeks, the occurrence of headaches in rats was evaluated through behavioral scores. The immunohistochemistry staining method was applied to observe the expression levels of headache-related neurotransmitters in the brain. Masson trichrome staining results showed that the number of collagen fibers of MDBC was increased in the BLM group compared to those of the other two groups. It revealed hyperplastic changes of MDBC. The behavioral scores of the BLM group were significantly higher than those of the PBS group and the blank control group. Meanwhile, expression levels of CGRP and 5-HT in the headache-related nuclei of the brain were increased in the BLM group. The current study further confirms the view that there is a relationship between pathological changes of MDBC and chronic headaches of unknown cause. This study may provide anatomical and physiological explanations for the pathogenesis of some chronic headaches of unknown cause.

Cervicogenic headache - How to recognize and treat

Cervicogenic headache, described almost 100 years ago, only had its clinical awakening at the end of the century with the work of Professor Sjaastad. Its classic definition is the induction of trigeminal symptoms from cervical disorders, thanks to trigeminocervical convergence mechanisms. For this reason, it can manifest several features typical of migraine, leading to diagnostic errors. Classically, subjects complain of fixed unilateral headaches, with cervical onset and trigeminal irradiation, associated with reduced neck mobility and flexion strength. The headache is mild to moderate, described as pulsatile or compressive, accompanied by nausea, vomiting, photophobia, phonophobia, and may present autonomic symptoms and dizziness. The pain duration varies from one day to weeks, and its frequency is unpredictable. A history of whiplash injury is common. The differential diagnosis encompasses migraine and tension-type headache. Management includes physiotherapy rehabilitation, anesthetic blocks, and selectively surgical procedures. In this article, all these aspects were extensively covered.

Potential mechanisms for osteopathic manipulative treatment to alleviate migraine-like pain in female rats

Introduction

Migraines are the leading cause of disability in the United States, and the use of non-pharmaceutical treatments like osteopathic manipulative treatment (OMT) has shown promise. Despite its potential, the lack of mechanistic understanding has hindered widespread adoption. This study aims to investigate the efficacy of OMT in treating acute migraines and unravel its underlying mechanisms of action.

Methods

Female rats were subjected to a "two-hit" approach to induce migraine-like pain. This involved bilateral injections of Complete Freund's Adjuvant (CFA) into the trapezius muscle (1st hit) followed by exposure to Umbellulone, a human migraine trigger, on Day 6 post-CFA (2nd hit). Soft tissue and articulatory techniques were applied to the cervical region for acute abortive or repeated prophylactic treatment. Cutaneous allodynia and trigeminal system activation were assessed through behavioral tests and immunohistochemical staining.

Results

Following Umbellulone inhalation, CFA-primed rats exhibited periorbital and hind paw allodynia. Immediate application of OMT after Umbellulone inhalation as an abortive treatment partially alleviated cutaneous allodynia. With OMT applied thrice as a prophylactic measure, complete suppression of tactile hypersensitivity was observed. Prophylactic OMT also prevented the increase of c-fos signals in the trigeminal nucleus caudalis and the elevation of calcitonin gene-related peptide expression in trigeminal ganglia induced by CFA and Umbellulone exposure at 2 h post-inhalation.

Discussion

These findings provide mechanistic insights into OMT's migraine-relief potential and underscore its viability as a non-pharmacological avenue for managing migraines.

Immediate effects of superficial dry needling of the trigeminal nerve innervation field for participants with cervicogenic headache. A randomized controlled trial

BACKGROUND

Cervicogenic headache (CGH) is a common condition with a neuroanatomical basis involving the trigeminal nerve. Dry needling (DN) is a safe and effective treatment for CGH but most studies involve deep DN to cervical musculature.

OBJECTIVE

The aim of this study was to investigate immediate effects of superficial DN of the trigeminal nerve innervation field on numeric pain rating scale (NPRS), flexion-rotation test (FRT), cervical range of motion (AROM), and pain-pressure threshold (PPT) of right (R) and left (L) supraorbital (SO), and right (R) and left (L) greater occipital (GO) nerves in participants with CGH.

METHODS

A parallel controlled randomized design involving 30 participants with CGH received either superficial DN (N = 17) or sham DN (N = 13). Participants and outcome assessors were blind to group assignment. Wilcoxon signed rank analyzed within-group effects and Mann-Whitney U analyzed between-group.

RESULTS

Statistically significant between-group differences were observed for NPRS (P < .001) and AROM (P < .006) favoring DN and were clinically meaningful. Right and left Flexion rotation tests (FRT) outcomes were non-significant (P = .137) but clinically meaningful. No differences were observed for PPT over: R SO (P = .187); L SO (P = .052); R GO (P = .187); or L GO (P = .052). Between-group effect sizes across variables were moderate to large (0.53-1.4) but confidence intervals were wide.

CONCLUSION

Superficial DN targeting the innervation field of the trigeminal nerve improves clinical outcomes in patients with CGH. Only the immediate effects were analyzed and the sample size was small. Larger, longer-term assessments are needed comparing superficial DN of the trigeminal innervation field and other conservative interventions for CGH.

Neck pain and headache: Pathophysiology, treatments and future directions

INTRODUCTION

Neck pain is a prevalent neurologic and musculoskeletal complaint in the general population and is often associated with primary headache disorders such as migraine and tension-type headache (TTH). A considerable proportion, ranging from 73% to 90%, of people with migraine or TTH also experience neck pain, and there is a positive correlation between headache frequency and neck pain. Furthermore, neck pain has been identified as a risk factor for migraine and TTH. Although the exact underlying mechanisms linking neck pain to migraine and TTH remain uncertain, pain sensitivity appears to play an important role. People with migraine or TTH exhibit lower pressure pain thresholds and higher total tenderness scores compared with healthy controls.

PURPOSE

This position paper aims to provide an overview of the current evidence on the relationship between neck pain and comorbid migraine or TTH. It will encompass the clinical presentation, epidemiology, pathophysiology, and management of neck pain in the context of migraine and TTH.

IMPLICATIONS

The relationship between neck pain and comorbid migraine or TTH is incompletely understood. In the absence of robust evidence, the management of neck pain in people with migraine or TTH relies mostly on expert opinion. A multidisciplinary approach is usually preferred, involving pharmacologic and non-pharmacologic strategies. Further research is necessary to fully dissect the linkage between neck pain and comorbid migraine or TTH. This includes the development of validated assessment tools, evaluation of treatment effectiveness, and exploration of genetic, imaging, and biochemical markers that might aid in diagnosis and treatment.

Evaluation and management of temporomandibular disorders. Part 1: an orthopedic physical therapy update on examination and clinical reasoning

Temporomandibular (TM) disorders afflict many people globally and, despite the presence of existing peer-reviewed material that assists conservative orthopedic providers, recent advances in knowledge indicate that updated resources are required for students, clinicians, and educators. This two-part series builds off previously published material to present newer supplementary information that can be useful during the evaluation and management processes. Content in Part 1 of this series includes a discussion about the factors that have been shown to contribute to TM disorders, an updated perspective of relevant pain science, a discussion of self-report outcome measures, and various different topics related to the examination of patients with TM disorders. Part 2 addresses information related to the temporomandibular joint disc, joint hypermobility, oral splints, and clinical reasoning. In combination with other available publications, this two-part series provides clinicians an opportunity to improve their delivery of effective and efficient clinical services for people diagnosed with TM disorders.

Nerve blocks for occipital headaches: A systematic review and meta-analysis

Migraine surgeons have identified six "trigger sites" where cranial nerve compression may trigger a migraine. This study investigates the change in headache severity and frequency following nerve block of the occipital trigger site. This PRISMA-compliant systematic review of five databases searched from database inception through May 2020 is registered under the PROSPERO ID: CRD42020199369. Only randomized controlled trials utilizing injection treatments for headaches with pain or tenderness in the occipital scalp were included. Pain severity was scored from 0 to 10. Headache frequency was reported as days per week. Included were 12 RCTs treating 586 patients of mean ages ranging from 33.7 to 55.8 years. Meta-analyses of pain severity comparing nerve blocks to baseline showed statistically significant reductions of 2.88 points at 5 to 20 min, 3.74 points at 1 to 6 weeks, and 1.07 points at 12 to 24 weeks. Meta-analyses of pain severity of nerve blocks compared with treatment groups of neurolysis, pulsed radiofrequency, and botulinum toxin type A showed similar headache pain severity at 1 to 2 weeks, and inferior improvements compared with the treatment groups after 2 weeks. Meta-analyses of headache frequency showed statistically significant reductions at 1 to 6-week follow-ups as compared with baseline and at 1 to 6 weeks as compared with inactive control injections. The severity and frequency of occipital headaches are reduced following occipital nerve blocks. This improvement is used to predict the success of migraine surgery. Future research should investigate spinous process injections with longer follow-up.

Are Morphometric Alterations of the Deep Neck Muscles Related to Primary Headache Disorders? A Systematic Review

This systematic review aims to summarise the evidence from studies that examined morphometric alterations of the deep neck muscles using diagnostic imaging (ultrasound imaging, magnetic resonance imaging, and computed tomography) in patients diagnosed with primary headache disorders (PHD). No previous reviews have focused on documenting morphometric changes in this population. We searched five databases (up to 12 November 2022) to identify the studies. The risk of bias (RoB) was assessed using the Quality in Prognostic Studies (QUIPS) tool and the overall quality of the evidence was assessed using The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. A total of 1246 studies were screened and five were finally included; most were at high RoB, and the overall level of confidence in results was very low. Only two studies showed a significant association between morphometric alterations of the deep neck muscles and PHD (p < 0.001); nevertheless, their RoB was high. Contradictory and mixed results were obtained. The overall evidence did not show a clear association between morphometric alterations of the deep neck muscles in patients diagnosed with PHD. However, due to the limited number of studies and low confidence in the evidence, it is necessary to carry out more studies, with higher methodological quality to better answer our question.

Greater occipital nerve blockade for the preventive treatment of chronic migraine: A randomized double-blind placebo-controlled study

BACKGROUND

Greater occipital nerve blockade for the prevention of chronic migraine has a limited evidence base. A robust randomized double-blind, placebo-controlled trial is needed.

METHODS

This double-blind, placebo-controlled, parallel-group trial, following a baseline period of four weeks, randomly assigned patients of chronic migraine 1:1 to receive four-weekly bilateral greater occipital nerve blockade with either 2 ml of 2% (40 mg) lidocaine (active group) or 2 ml of 0.9% saline (placebo) injections for 12 weeks. The primary and key secondary efficacy endpoints were a change from the baseline in the mean number of headache and migraine days and the achievement of ≥50% reduction in headache days from baseline across the weeks 9-12 respectively. Safety evaluations included the documentation and reporting of serious and other adverse events.

RESULTS

Twenty-two patients each were randomly allocated to the active and placebo group. Baseline demography and clinical characteristics were similar between the two groups. Mean headache and migraine days at baseline (±SD) were 23.4 ± 4.4 and 15.6 ± 5.7 days in the active group and 22.6 ± 5.0 and 14.6 ± 4.6 days in the placebo group respectively. The active group compared to the placebo had a significantly greater least-squares mean reduction in the number of headache and migraine days (-4.2 days [95% CI: -7.5 to -0.8; p  =  0.018] and -4.7 days [95%CI: -7.7 to -1.7; p = 0.003] respectively). 40.9% of patients in the active group achieved ≥50% reduction in headache days as compared with 9.1% of patients receiving a placebo (p = 0.024). Overall, 64 mild and transient adverse events were reported by 16 patients in the active group and 15 in the placebo. No death or serious adverse events were reported.

CONCLUSION

Four-weekly greater occipital nerve blockade with 2% lidocaine for 12 weeks was superior to placebo in decreasing the average number of headache and migraine days in patients with chronic migraine with a good tolerability profile.Clinical trial.gov no. CTRI 2020/07/026709.

Pain sensitivity in relation to frequency of migraine and tension-type headache with or without coexistent neck pain: an exploratory secondary analysis of the population study

OBJECTIVES

We aimed to investigate whether coexistent self-reported neck pain influences cephalic and extracephalic pain sensitivity in individuals with migraine and tension-type headache (TTH) in relation to diagnosis and headache frequency.

METHODS

A population of 496 individuals completed a headache interview based on ICHD criteria, providing data collected by self-administered questionnaires, assessments of pericranial total tenderness score (TTS) and pressure pain thresholds (PPT). Stimulus-response (SR) functions for pressure vs. pain were recorded. Presence of neck pain in the past year was assessed by the self-administered questionnaire. We categorized participants by primary headache type. We also categorized participants into 3 groups by headache frequency: chronic (≥15) or episodic (<15 headache days/month) headache and controls. TTS, PPTs and the area under the SR curve were compared between subgroups using Generalized Linear Models with pairwise comparisons controlling for age and sex.

RESULTS

Individuals with chronic followed by episodic headache had higher TTS than controls (overall p≤0.001). The difference between chronic and episodic headache subgroups was significant in the group with neck pain (p≤0.001) but not in the group without neck pain. In individuals with neck pain, mean TTS was higher in coexistent headache (migraine and TTH), 23.2 ± 10.7, and pure TTH, 17.8 ± 10.3, compared to pure migraine, 15.9 ± 10.9 and no headache 11.0 ± 8.3 (overall p<0.001). Temporal and finger PPTs did not statistically differ among the chronic headache, the episodic headache and controls in individuals with and without neck pain. Temporalis and trapezius SR-functions showed that tenderness was increased in individuals with chronic headache to higher degree than in those with episodic headache, and more so in those with neck pain.

CONCLUSIONS

Coexistent neck pain is associated with greater pericranial tenderness in individuals with chronic headache and to a lesser degree in those with episodic headache. Sensitization may be a substrate or consequence of neck pain and primary headache, but a longitudinal study would be needed for further clarification.

Ipsilateral Limb Extension of Referred Trigeminal Facial Pain due to Greater Occipital Nerve Entrapment: A Case Report

We report a very rare case of referred pain associated with entrapment of the greater occipital nerve (GON) occurring not only in the ipsilateral hemiface but also in the ipsilateral limb. There is an extensive convergence of cutaneous, tooth pulp, visceral, neck, and muscle afferents onto nociceptive and nonnociceptive neurons in the trigeminal nucleus caudalis (medullary dorsal horn). In addition, nociceptive input from trigeminal, meningeal afferents projects into trigeminal nucleus caudalis and dorsal horn of C1 and C2. Together, they form a functional unit, the trigeminocervical complex (TCC). The nociceptive inflow from suboccipital and high cervical structures is mediated with small-diameter afferent fibers in the upper cervical roots terminating in the dorsal horn of the cervical cord extending from the C2 segment up to the medullary dorsal horn. The major afferent contribution is mediated by the spinal root C2 that is peripherally represented by the greater occipital nerve (GON). Convergence of afferent signals from the trigeminal nerve and the GON onto the TCC is regarded as an anatomical basis of pain referral in craniofacial pain and primary headache syndrome. Ipsilateral limb pain occurs long before the onset of the referred facial pain. The subsequent severe hemifacial pain suggested GON entrapment. The occipital nerve block provided temporary relief from facial and extremity pain. Imaging studies found a benign osteoma in the ipsilateral suboccipital bone, but no direct contact with GON was identified. During GON decompression, severe entrapment of the GON was observed by the tendinous aponeurotic edge of the trapezius muscle, but the osteoma had no contact with the nerve. Following GON decompression, the referred trigeminal and extremity pain completely disappeared. The pain referral from GON entrapment seems to be attributed to the sensitization and hypersensitivity of the trigeminocervical complex (TCC). The clinical manifestations of TCC hypersensitivity induced by chronic entrapment of GONs are diverse when considering the occurrence of extremity pain as well as facial pain.

Bening paraxysmal torticollis is a sensoriomotos trigeminocervical convergence merchanisms? Experimental evidence

Introduction Benign paroxysmal torticollis (BPT) is likely an age-sensitive, childhood periodic syndromes that are commonly precursors of migraine, with atypical postural behavior (torticollis) to start early and self-limited, which of unknown etiology. Objective To prove the existence of forms of sensorimotor convergence between the trigeminal nerve and upper cervical roots respectively. Methods Ninety-five rats Norvegicus were submitted to infraorbital nerve blockade using botulinum neurotoxin type A (BoNT/A) (n=48) controlled by isotonic saline solution animals (ISS) (n=47). After 84 days the animals were evaluated on their motor functions using open field test and postural behavior. Results Of the 48 animals in the BoNT/A group one animal showed the torticollis ipsilateral to BoNT/A injection. The macroscopic analysis showed fasciculations on clavotrapezius muscle. The biopsy with optical and electronic microscopy of this muscle showed changes suggestive of denervation secondary to BoNT/A. Conclusion We suggested the existence of a pathway sensoriomotor probably in the brainstem involves the trigeminal system and cervical motoneurons.  

Outcomes of transcutaneous nerve stimulation for migraine headaches: a systematic review and meta-analysis

BACKGROUND

Implanted and transcutaneous nerve stimulators have shown promise as novel non-pharmacologic treatment for episodic and chronic migraines. The purpose of this study was to summarize the reported efficacy of transcutaneous single nerve stimulators in management of migraine frequency and severity.

METHODS

A systematic review of five databases identified studies treating migraines with transcutaneous stimulation of a single nerve. Random effects model meta-analyses were conducted to establish the effect of preventive transcutaneous nerve stimulation on headache days per month and 0-10 numeric rating scale pain severity of headaches for both individuals with episodic and chronic migraines.

RESULTS

Fourteen studies, which treated 995 patients, met inclusion criteria, including 7 randomized controlled trials and 7 uncontrolled clinical trials. Transcutaneous nerve stimulators reduced headache frequency in episodic migraines (2.81 fewer headache days per month, 95% CI 2.18-3.43, I² = 21%) and chronic migraines (2.97 fewer headache days per month, 95% CI 1.66-4.28, I² = 0%). Transcutaneous nerve stimulators reduced headache severity in episodic headaches (2.23 fewer pain scale points, 95% CI 1.64-2.81, I² = 88%).

CONCLUSIONS

Preventive use of transcutaneous nerve stimulators provided clinically significant reductions in headache frequency in individuals with chronic or episodic migraines. Individuals with episodic migraines also experienced a reduction in headache pain severity following preventive transcutaneous nerve stimulation.

Prevalence of trigeminocervical convergence mechanisms in episodic and chronic migraine

BACKGROUND

Migraine pain location and trigeminocervical convergence have limited diagnostic value and have usually been assessed using non-standard verbal descriptors in a small number of centers.

OBJECTIVE

To use non-verbal descriptors of migraine pain location to determine the prevalence of trigeminocervical convergence mechanisms in patients with episodic and chronic migraine. In addition, we explored the factors associated with the presence of convergence.

METHODS

A multicenter study was carried out. The explicit pain location was explored by asking subjects to indicate, on an electronic form, three points on the anterolateral side and three points on the posterolateral side of the head and neck that represented the common locations of their migraine pain. We evaluated associations of the pain pattern with demographic and psychological features, comorbidities, lifestyle and other headache characteristics.

RESULTS

97 episodic and 113 chronic migraine patients were included. Convergence was present in 116 migraineurs (55%) who indicated dominance of pain in the posterior cervical region. This site was more often involved in the chronic migraine group (21 vs. 33%; p=0.034). The number of migrainous/altered sensitivity symptoms (OR=1.39; 95%CI 1.14-1.71) was associated with convergence independently of the chronification status. In this symptom group, there were statistical associations between convergence and vomiting (p=0.045), tactile allodynia (p<0.001), nuchal rigidity (p<0.001) and movement allodynia (p=0.031).

CONCLUSIONS

Trigeminocervical convergence is common in migraineurs and, in practice, it might be found frequently in chronic migraineurs. Some features commonly found in this group, such as altered sensitivity symptoms, are associated with this phenomenon.

Greater Occipital Nerve Block with Local Anesthetics and Corticosteroids in Treatment-Resistant Chronic Migraine

Objective: We investigated the efficacy and tolerability of greater occipital nerve block with lidocaine plus betamethasone in adults with chronic migraine in whom two or more previous preventive treatments were unsuccessful. Methods: Ten participants were enrolled in a 24-weeks, randomized, double-blind, placebo-controlled, crossover trial conducted at a single tertiary headache center in Copenhagen (Denmark). After a 4-week run-in period, participants underwent treatment with bilateral greater occipital nerve block with lidocaine plus betamethasone (GONb) or lidocaine plus saline (placebo) with a 4-week interval wash-out phase between the 8-week crossover periods. The primary aim was to compare the number of migraine days during crossover periods after GONb or placebo. This trial is registered at ClinicalTrials.gov (NCT02686983). Results: This study was stopped before achieving the a priori sample size, due to a slow enrollment. Ten participants were recruited, completed the study and were included in the analyses. At the baseline, the mean number of monthly migraine days was 22.9 (range, 14-30). No difference between GONb and placebo on the reduction of monthly migraine days was observed (p = 0.147; 95% CI between 0.6 and 3.7 days). Adverse events were recorded in two patients after GONb, compared with three patients after placebo. Conclusions: GONb is not beneficial in patients with difficult-to-treat chronic migraine.

Decompression of the Greater Occipital Nerve for Persistent Headache Attributed to Whiplash Accompanying Referred Facial Trigeminal Pain

OBJECTIVE

Persistent headache attributed to whiplash (PHAW) is defined as a headache that occurs for the first time in close temporal relation to whiplash lasting more than 3 months. We investigated the results of decompression of the greater occipital nerve (GON) in patients with PHAW who presented with referred trigeminal facial pain caused by sensitization of the trigeminocervical complex) along with occipital headache.

METHODS

A 1-year follow-up study of GON decompression was conducted in 7 patients with PHAW manifesting referred facial trigeminal pain. The degree of pain reduction was analyzed using the numeric rating scale (NRS-11) and percent pain relief before and 1 year after surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Clinical characteristics of headache and facial pain and surgical findings were studied.

RESULTS

GON decompression was effective in all 7 patients with PHAW manifesting referred trigeminal pain, with a percent pain relief of 83.06 ± 17.30. The pain had disappeared in 3 of 7 patients (42.9%) within 6 months and no further treatment was needed. Patients' assessment of subjective improvement based on a 10-point Likert scale was 7.23 ± 1.25. It was effective in both occipital and facial pain.

CONCLUSIONS

Although chronic GON entrapment itself is an individual constitutional issue, postwhiplash inflammatory changes seem to trigger chronic occipital headaches in GON distribution and unexplained referred trigeminal pain caused by sensitization of the trigeminocervical complex.

Intracranial nociception

Understanding intracranial nociceptive innervation is essential to understand the pathophysiology of headaches. Our knowledge about human intracranial nociception comes from sparse observations during neurosurgical procedures performed in awake patients, from human anatomical studies and from experimental studies in animals. In this article we review the anatomical and functional organization underlying nociceptive innervation. Intracranial nociception is mainly mediated by the trigeminal system, except in the posterior cranial fossa that is innervated by the first cervical roots. For decades, the dura mater, its vessels and major cerebral blood vessels were considered as the only intracranial pain-sensitive structures. Recent animal and human studies have suggested that smaller brain arteries and potentially pia mater might also be pain sensitive. Nociceptive neurons innervating intracranial blood vessels project via the ophthalmic division (V1) to the trigeminal ganglion and store several neurotransmitters including glutamate, substance P and calcitonin gene-related peptide (CGRP). The trigeminal ganglion, root and brainstem nuclei have a specific topographic and functional somatotopy. Progressive transition between the trigeminal spinal nucleus and the dorsal horn of the cervical spinal cord, and convergence of nociceptive inputs from the face, intracranial structures and the occipital area on the so-called "trigemino-cervical complex" may explain some headache features, relations between facial and occipital pain, and efficacy of occipital nerve stimulation in headache. The specific anatomic organization of the trigeminal system, from the primary-order neuron in the trigeminal ganglion, to the second-order neuron is the trigeminal nuclei, may explain a part of the various characteristics of headaches.

Experimental evidence of a functional relationship within the brainstem trigeminocervical complex in humans

ABSTRACT

The existence of a trigeminocervical complex (TCC) has been suggested based on animal data, but only indirect evidence exists in humans. We investigated the functional relationship between the trigeminal and the occipital region by stimulating one region and measuring electrical pain thresholds (EPTs) of the corresponding opposite region. This study consists of two single-blinded, randomized protocols. 40 healthy participants were recruited in the propaedeutic Protocol I. EPTs were measured on the V1 and the greater occipital nerve (GON) dermatome bilaterally as well as on the left forearm longitudinally before and after application of topical capsaicin. Protocol II was then online pre-registered and, additionally, the ipsilateral trigeminal dermatomes V2 and V3 were tested. GON stimulation increased the EPT ipsilateral at V1 after 20 minutes (p=0.006) compared to baseline, whereas trigeminal stimulation increased the EPT at the ipsilateral (p=0.023) as well as the contralateral GON (p=0.001) following capsaicin application. Protocol II confirmed these results and additionally showed that GON stimulation with capsaicin increased EPTs ipsilateral at all three trigeminal dermatomes and that trigeminal stimulation on V1 led to an ipsilateral increase of EPTs at GON, V2 and V3. Our data suggest a strong functional interplay between the trigeminal and occipital system in humans. The fact that stimulation of one of these dermatomes increases the electrical pain threshold of the respective other nerve could be explained by segmental inhibition on brainstem level.

Ultrasound-guided peripheral nerve interventions for common pain disorders

There are a number of common pain disorders that can be managed effectively by injections around or ablation of peripheral nerves. Ultrasound is a universally available imaging tool, is safe, cost-effective, and is excellent in imaging many peripheral nerves and guiding needles to the site of the nerves. This article aims to present an overview of indications and techniques of such procedures that can be effectively performed by a radiologist.

Occipital Neuralgia and Its Management: An Overview

Background

Greater and lesser occipital neuralgias are primary neuralgias that are relatively uncommon, where the pain is felt in the distribution of these nerves.

Objective

This review paper was intended to describe the features and management of occipital neuralgia in the context of a challenging case.

Material and Methods

We looked at succinct literature from the past 30 years. We compared the features of our challenging case given in the current literature. In addition, an overview of the current literature is provided.

Results

The case, although proved to be a diagnostic challenge, we were able to reach a conclusion and render the patient almost complete pain relief by conservative management modalities. It proved to be a rare presentation of occipital neuralgia with unusual pain distribution, and we are able to describe a literature-based explanation for this entity to be a diagnostic and management challenge.

Conclusion

Primary headaches, i'n general, are a group of headache disorders that require exquisite diagnostic skills. The clinical history is a key factor when making an accurate diagnosis, and to establish an appropriate management plan.

Effects of greater occipital nerve block with local anesthetic and triamcinolone for treatment of medication overuse headache: an open-label, parallel, randomized, controlled clinical trial

AIM

There is a paucity of evidence and consensus on exactly how to carry out the detoxification process. To examine the effect of a greater occipital nerve block (GONB) in the detoxification process, we conducted an open-label, parallel, randomized, controlled clinical trial.

MATERIALS AND METHODS

In order to conduct this study, 54 medication-overuse headache (MOH) patients were recruited and allocated randomly to group A (n = 27) or B (n = 27). In both groups, patients underwent detoxification processes without any acute migraine medication or analgesics. During the run-in period, all patients in both groups received the same education, managed by a neurologist and nutritionist. All patients were offered maximally 300 mL of promethazine syrup (5 mg/5 mL) to be taken 10 mg every 8 h during the first 10 days of the study. A 2-mL syringe containing 1 mL of lidocaine 2% and 1 mL of triamcinolone 40 mg/mL was prepared for each patient of group A for conducting GONB. Characteristics of headache attacks, including headache severity, frequency, and duration, were assessed at baseline and after 3 months of intervention.

RESULTS

Twenty-six patients in group A (96.3%) and twenty-three in group B (85.2%) completed detoxification, and were thus cured of MOH (P = 0.351). The present study revealed that GONB with local anesthetic and triamcinolone significantly improved the characteristics of headache, including frequency (- 13.66 in group A and - 7.55 in group B), duration (- 7.92 in group A and - 5.88 in group B), and severity (- 3.44 in group A vs. - 1.33 in group B) in group A compared to control (all P value < 0.05).

CONCLUSIONS

Although both detoxification programs were effective, detoxification with GONB resulted in better outcomes.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (registration number; IRCT20150906023922N2).

Headache from clinically confirmed hemicrania continua arising from the sternocleidomastoid muscle: a case report

Background

A patient with a history of cluster headaches, now in remission, presented with confirmed hemicrania continua that resolved with a local anaesthetic injection into the Sternocleidomastoid (SCM) muscle. To the best of our knowledge, this is the first reported case of a trigeminal autonomic cephalalgia arising from a soft tissue source in the neck.

Case presentation

A 66-year-old man with a history of cluster headaches presented with a six-month history of a new constant right-sided headache. The new headaches were associated with tearing and redness of the right eye and responded to indomethacin, thus meeting the International Classification of Headache Disorders (ICHD-3) diagnostic criteria for hemicrania continua. The history and physical examination suggested a cervical source of the headache arising from the ipsilateral SCM muscle. Injection of the muscle with 1% lidocaine resulted in the elimination of the pain for 1 month without indomethacin.

Conclusions

Due to the convergence of trigeminal, cervical and autonomic nerve fibres, various combinations of headache syndromes can result. This case report demonstrates how a meticulous examination is a crucial component of headache evaluation. Treatment directed to this muscle spared this patient further daily indomethacin and associated side effects.

Entrapment of the Greater Occipital Nerve with Chronic Migraine and Severe Facial Pain: A Case Report

Migraine is thought to be a primary neurovascular headache due to brain dysfunction and is known to involve peripheral and central sensitization. A female patient with chronic migraine symptoms for 30 years reported severe pain in the deep ear and face. This headache always showed the same pattern and temporal progression. The sudden onset of ache and throbbing pain in the right temporo-occipital area extended to the left temporo-occipital areas. She felt sick as if the head would burst, and nausea and vomiting occurred. During the last 3 years, the patient endured sharp pain in bilateral deep ears and severe pain in the face as if all the facial bones were broken, and tears flowed. Chronic disabling headache and facial pain improved with the decompression of the greater occipital nerve. This case suggests that peripheral sensitization may be related to the pathophysiology of migraine, especially in the migraine without aura.

Muscle endurance training of the neck triggers migraine attacks

BACKGROUND

Most migraine patients report neck pain as part of their migraine symptomatology, but it is unknown whether triggering neck pain would induce migraine attacks. Our aim was to assess the occurrence of headache and/or neck pain after an endurance test of the neck muscles among migraineurs and controls.

METHODS

Sixty-five patients with migraine and 32 headache-free participants underwent a manual examination of the cervical spine by an assessor blinded towards the diagnosis and were sub-classified according to the appearance or absence of neck pain. Subsequently, the endurance of the neck flexors and extensors was tested three times, in a random order. The maximum sustained duration was recorded and the test was terminated when the subject was unable to maintain the position or reported pain. On the day after the assessment, participants were asked to report the potential occurrence of headache or neck symptoms.

RESULTS

None of the controls reported headache after assessment, while migraine-like headache was reported by 42% of the patients with migraine (p < 0.001) after 15.8 h (SD: 10.0). Neck pain was more prevalent in migraineurs compared to controls (45% vs. 16%, p = 0.006). When considering the neck pain subtype, there were no differences among the three profiles regarding neck pain but participants with referred pain to the head reported a migraine attack more often (45%, p = 0.03).

CONCLUSION

Patients with migraine are more likely to report neck pain and migraine attacks following a neck muscle endurance test. Participants with neck pain referred to the head during manual examination had a greater prevalence of migraine attacks than those without or with only local pain.

J-A Barré’s historic article “On posterior cervical sympathetic syndrome”: A translation from French

Barré’s 1926 report “Sur un syndrome sympathique cervicale postérieure et sa cause fréquente: l’arthrite cervicale” is arguably the first description of what we now call cervicogenic headache. Barré’s contribution to the subject and significant insights, which have stood the test of time, are insufficiently recognised. This article is an English translation of Barré’s French original.

Referred Trigeminal Facial Pain from Occipital Neuralgia Occurring Much Earlier than Occipital Neuralgia

We report a very rare case in which a patient believed to have auriculotemporal neuralgia due to the repeated recurrence of paroxysmal stabbing pain in the preauricular temporal region for four years developed occipital neuralgia, which finally improved with decompression of the greater occipital nerve (GON). The pain of occipital neuralgia has been suggested to be referred to the frontoorbital (V1) region through trigeminocervical interneuronal connections in the trigeminal spinal nucleus. However, the reports of such cases are very rare. In occipital neuralgia, the pain referred to the ipsilateral facial trigeminal region reportedly also occurs in the V2 and V3 distributions in addition to that in the V1 region. In the existing cases of referred trigeminal pain from occipital neuralgia, continuous aching pain is usually induced, but in the present case, typical neuralgic pain was induced and diagnosed as idiopathic auriculotemporal neuralgia. In addition, recurrent trigeminal pain occurred for four years before the onset of occipital neuralgia. If the typical occipital neuralgia did not develop in four years, it would be impossible to infer an association with the GON. This case shows that the clinical manifestations of referred trigeminal pain caused by the sensitization of the trigeminocervical complex by chronic entrapment of the GON can be very diverse.

Alleviation of migraine symptoms by application of repetitive peripheral magnetic stimulation to myofascial trigger points of neck and shoulder muscles - A randomized trial

Migraine is a burdensome disease with an especially high prevalence in women between the age of 15 and 49 years. Non-pharmacological, non-invasive therapeutic methods to control symptoms are increasingly in demand to complement a multimodal intervention approach in migraine. Thirty-seven subjects (age: 25.0 ± 4.1 years; 36 females) diagnosed with high-frequency episodic migraine who presented at least one active myofascial trigger point (mTrP) in the trapezius muscles and at least one latent mTrP in the deltoid muscles bilaterally prospectively underwent six sessions of repetitive peripheral magnetic stimulation (rPMS) over two weeks. Patients were randomly assigned to receive rPMS applied to the mTrPs of the trapezius (n = 19) or deltoid muscles (n = 18). Whereas the trapezius muscle is supposed to be part of the trigemino-cervical complex (TCC) and, thus, involved in the pathophysiology of migraine, the deltoid muscle was not expected to interfere with the TCC and was therefore chosen as a control stimulation site. The headache calendar of the German Migraine and Headache Society (DMKG) as well as the Migraine Disability Assessment (MIDAS) questionnaire were used to evaluate stimulation-related effects. Frequency of headache days decreased significantly in both the trapezius and the deltoid group after six sessions of rPMS (trapezius group: p = 0.005; deltoid group: p = 0.003). The MIDAS score decreased significantly from 29 to 13 points (p = 0.0004) in the trapezius and from 31 to 15 points (p = 0.002) in the deltoid group. Thus, rPMS applied to mTrPs of neck and shoulder muscles offers a promising approach to alleviate headache frequency and symptom burden. Future clinical trials are needed to examine more profoundly these effects, preferably using a sham-controlled setting.

Ictal neck pain investigated in the interictal state – a search for the origin of pain

Background

Neck pain is reported in more than 50% of migraine patients during migraine attacks and may be an important source to migraine pain.

Objectives

To investigate phenotypical differences between migraine patients with and without ictal neck pain in the interictal phase. Additionally, to prospectively examine the association between pericranial muscle tenderness and the impending migraine attack.

Methods

Migraine patients (n = 100) and controls (n = 46) underwent a semi-structured interview and sensory testing interictally. Pericranial muscle tenderness was determined using total tenderness score and local tenderness score. The occurrence of migraine attacks was then prospectively recorded for the following seven days.

Results

Patients with ictal neck pain had increased tenderness of pericranial neck muscles compared to migraine patients without ( p = 0.023). Ictal neck pain was not associated with migraine localization, tension-type headache, or markers of central sensitization. Prospective data of 84 patients showed that tenderness of trigeminal sensory innervated muscles increased the migraine attack rate ( p = 0.035).

Conclusion

The distinction of migraine patients based on the occurrence of ictal neck pain could indicate migraine subtypes and possible involvement of peripheral tissue in the pathophysiology. Whether treatment responses differ among these groups would be fascinating. Additionally, we found that cephalic muscle tenderness is a risk factor for an impending migraine attack.

Repetitive Peripheral Magnetic Stimulation (rPMS) in Subjects With Migraine-Setup Presentation and Effects on Skeletal Musculature

Purpose: Repetitive peripheral magnetic stimulation (rPMS) has been successfully applied recently in migraineurs to alleviate migraine symptoms. Symptom relief has been achieved by stimulating myofascial trigger points (mTrPs) of the trapezius muscles, which are considered part of the trigemino-cervical complex (TCC). However, effects on musculature have not been assessed in detail, and the specificity of effects to muscles considered part of the TCC yet has to be elucidated. Against this background, this study presents the setup of rPMS in migraine and evaluates effects on skeletal musculature. Materials and Methods: Thirty-seven adults (mean age: 25.0 ± 4.1 years, 36 females) suffering from migraine and presenting mTrPs according to physical examination underwent rPMS either to mTrPs in the trapezius muscles (considered part of the TCC; n = 19) or deltoid muscles (considered not part of the TCC; n = 18) during six sessions over the course of 2 weeks. Standardized questionnaires were filled in to assess any adverse events and experience with rPMS as well as satisfaction and benefits from stimulation. Algometry was performed to evaluate changes in pressure pain thresholds (PPTs). Results: All stimulation sessions were successfully performed without adverse events, with 84.2% of subjects of the trapezius group and 94.4% of subjects of the deltoid group describing rPMS as comfortable (p = 0.736). Muscular pain or tension improved in 73.7% of subjects of the trapezius group and in 61.1% of subjects of the deltoid group (p = 0.077). PPTs of the trapezius muscles clearly increased from the first to the last stimulation sessions-regardless of the stimulated muscle (rPMS to the trapezius or deltoid muscles). However, depending on the examined muscles the increase of PPTs differed significantly (subjects with stimulation of trapezius muscles: p = 0.021; subjects with stimulation of deltoid muscles: p = 0.080). Conclusion: rPMS is a comfortable method in migraineurs that can improve local muscular pain or tension. Furthermore, it is able to increase directly and indirectly the PPTs of the trapezius muscles (considered part of the TCC) when applied over mTrPs, supporting the role of the TCC in migraineurs.

A Neuroscience Perspective of Physical Treatment of Headache and Neck Pain

The most prevalent primary headaches tension-type headache and migraine are frequently associated with neck pain. A wide variety of treatment options is available for people with headache and neck pain. Some of these interventions are recommended in guidelines on headache: self-management strategies, pharmacological and non-pharmacological interventions. Physical treatment is a frequently applied treatment for headache. Although this treatment for headache is predominantly targeted on the cervical spine, the neurophysiological background of this intervention remains unclear. Recent knowledge from neuroscience will enhance clinical reasoning in physical treatment of headache. Therefore, we summarize the neuro- anatomical and—physiological findings on headache and neck pain from experimental research in both animals and humans. Several neurophysiological models (referred pain, central sensitization) are proposed to understand the co-occurrence of headache and neck pain. This information can be of added value in understanding the use of physical treatment as a treatment option for patients with headache and neck pain.

Endogenous Neurostimulation and Physiotherapy in Cluster Headache: A Clinical Case

OBJECTIVE

The aim of this paper is to describe the progressive changes of chronic cluster headaches (CHs) in a patient who is being treated by a multimodal approach, using pharmacology, neurostimulation and physiotherapy.

SUBJECT

A male patient, 42 years of age was diagnosed with left-sided refractory chronic CH by a neurologist in November 2009. In June 2014, the patient underwent a surgical intervention in which a bilateral occipital nerve neurostimulator was implanted as a treatment for headache.

METHODS

Case report.

RESULTS

Primary findings included a decreased frequency of CH which lasted up to 2 months and sometimes even without pain. Besides this, there were decreased levels of anxiety, helplessness (PCS subscale) and a decreased impact of headache (HIT-6 scale). Bilateral pressure pain thresholds (PPTs) were improved along with an increase in strength and motor control of the neck muscles. These improvements were present at the conclusion of the treatment and maintained up to 4 months after the treatment.

CONCLUSIONS

A multimodal approach, including pharmacology, neurostimulation and physiotherapy may be beneficial for patients with chronic CHs. Further studies such as case series and clinical trials are needed to confirm these results.

Non-Trigeminal Nociceptive Innervation of the Posterior Dura: Implications to Occipital Headache

Current understanding of the origin of occipital headache falls short of distinguishing between cause and effect. Most preclinical studies involving trigeminovascular neurons sample neurons that are responsive to stimulation of dural areas in the anterior 2/3 of the cranium and the periorbital skin. Hypothesizing that occipital headache may involve activation of meningeal nociceptors that innervate the posterior ⅓ of the dura, we sought to map the origin and course of meningeal nociceptors that innervate the posterior dura overlying the cerebellum. Using AAV-GFP tracing and single-unit recording techniques in male rats, we found that neurons in C2-C3 DRGs innervate the dura of the posterior fossa; that nearly half originate in DRG neurons containing CGRP and TRPV1; that nerve bundles traverse suboccipital muscles before entering the cranium through bony canals and large foramens; that central neurons receiving nociceptive information from the posterior dura are located in C2-C4 spinal cord and that their cutaneous and muscle receptive fields are found around the ears, occipital skin and neck muscles; and that administration of inflammatory mediators to their dural receptive field, sensitize their responses to stimulation of the posterior dura, peri-occipital skin and neck muscles. These findings lend rationale for the common practice of attempting to alleviate migraine headaches by targeting the greater and lesser occipital nerves with anesthetics. The findings also raise the possibility that such procedures may be more beneficial for alleviating occipital than non-occipital headaches and that occipital migraines may be associated more closely with cerebellar abnormalities than in non-occipital migraines.SIGNIFICANCE STATEMENT Occipital headaches are common in both migraine and non-migraine headaches. Historically, two distinct scenarios have been proposed for such headaches; the first suggests that the headaches are caused by spasm or tension of scalp, shoulders, and neck muscles inserted in the occipital region, whereas the second suggests that these headaches are initiated by activation of meningeal nociceptors. The current study shows that the posterior dura overlying the cerebellum is innervated by cervicovascular neurons in C2 DRG whose axons reach the posterior dura through multiple intracranial and extracranial pathways, and sensitization of central cervicovascular neurons from the posterior dura can result in hyper-responsiveness to stimulation of neck muscles. The findings suggest that the origin of occipital and frontal migraine may differ.

Greater occipital nerve block in migraine prophylaxis: Narrative review

Objectives

The importance and popularity of peripheral nerve block procedures have increased in the treatment of migraine. Greater occipital nerve (GON) block is a commonly used peripheral nerve block method, and there are numerous researches on its use in migraine treatment.

Materials and methods

A search of PubMed for English-language randomized controlled trials (RCT) and open studies on greater occipital nerve block between 1995 and 2018 was performed using greater occipital nerve, headache, and migraine as keywords.

Results

In total, 242 potentially relevant PubMed studies were found. A sum of 228 of them which were non-English articles and reviews, case reports, letters and meta-analyses were excluded. The remaining articles were reviewed, and 14 clinical trials, seven of which were randomized-controlled on greater occipital nerve block in migraine patients, were identified and reviewed.

Conclusions

Although clinicians commonly use greater occipital nerve block in migraine patients, the procedure has yet to be standardized. The present study reviewed the techniques, drugs and dosages, the frequency of administration, side effects, and efficacy of greater occipital nerve block in migraine patients.

The greater occipital nerve and its spinal and brainstem afferent projections: A stereological and tract-tracing study in the rat

The neuromodulation of the greater occipital nerve (GON) has proved effective to treat chronic refractory neurovascular headaches, in particular migraine and cluster headache. Moreover, animal studies have shown convergence of cervical and trigeminal afferents on the same territories of the upper cervical and lower medullary dorsal horn (DH), the so-called trigeminocervical complex (TCC), and recent studies in rat models of migraine and craniofacial neuropathy have shown that GON block or stimulation alter nociceptive processing in TCC. The present study examines in detail the anatomy of GON and its central projections in the rat applying different tracers to the nerve and quantifying its ultrastructure, the ganglion neurons subserving GON, and their innervation territories in the spinal cord and brainstem. With considerable intersubject variability in size, GON contains on average 900 myelinated and 3,300 unmyelinated axons, more than 90% of which emerge from C₂ ganglion neurons. Unmyelinated afferents from GON innervates exclusively laminae I-II of the lateral DH, mostly extending along segments C_2-3 . Myelinated fibers distribute mainly in laminae I and III-V of the lateral DH between C₁ and C₆ and, with different terminal patterns, in medial parts of the DH at upper cervical segments, and ventrolateral rostral cuneate, paratrigeminal, and marginal part of the spinal caudal and interpolar nuclei. Sparse projections also appear in other locations nearby. These findings will help to better understand the bases of sensory convergence on spinomedullary systems, a critical pathophysiological factor for pain referral and spread in severe painful craniofacial disorders.

The effectiveness of greater occipital nerve blockade in treating acute migraine-related headaches in emergency departments

OBJECTIVE

This study aimed to evaluate the effectiveness of a greater occipital nerve (GON) blockade against a placebo and classical treatments (non-steroidal anti-inflammatory drugs + metoclopramide) among patients who were admitted to the emergency department (ED) with acute migraine headaches.

METHOD

This prospective-randomized controlled study was conducted on patients with acute migraine headaches. The patients were randomly assigned to 3 treatment groups: the GON blockade group (nerve blockade with bupivacaine), the placebo group (injection of normal saline into the GON area), and the intravenous (IV) treatment group (IV dexketoprofen and metoclopramide). Sixty acute migraine attack patients were assigned to 3 groups of 20 patients each. The pain severity was assessed at 5, 15, 30, and 45 minutes with a 10-point pain scale score (PSS).

RESULTS

The mean decreases in the 5-, 15-, 30-, and 45-minutes PSS scores were greater in the GON blockade group than in the dexketoprofen and placebo groups. When comparing the 30- and 45-minutes PSS changes, a statistically significant difference was found among the 3 groups (P = .03 and P = .03, respectively).

CONCLUSION

A GON blockade was as effective as an IV dexketoprofen + metoclopramide treatment and superior to a placebo in patients with acute migraine headaches. Despite being an invasive procedure, a GON blockade might be an effective option for acute migraine treatment in the ED due to its rapid, easy, and safe application.

Patients with Concomitant Chronic Neck Pain and Myofascial Pain in Masticatory Muscles Have More Widespread Pain and Distal Hyperalgesia than Patients with Only Chronic Neck Pain

Objective

Insufficient evidence exists to compare widespread pain (WP), pain sensibility, and psychological factors that occur in patients presenting with chronic neck pain (CNP) or a combination of temporomandibular disorder (TMD) and other complaints. The present study compared the pain sensibility and psychological factors of subjects with CNP with those with TMD + CNP.

Design

Cross-sectional study.

Setting

Local community.

Subjects

A nonprobabilistic convenience sample of 86 persons with CNP or TMD was recruited into three groups: CNP, TMD with myofascial pain in masticatory muscles with cocomitant CNP (TMD + CNP), and asymptomatic control groups consisted of 27, 29, and 30 participants, respectively.

Methods

Participants underwent a clinical examination to evaluate WP with computerized assessment based on the pain drawing, pressure pain thresholds (PPT), and psychological factors, which were evaluated using the pain catastrophizing scale (PCS) and the state-trait anxiety inventory (STAI).

Results

Statistically significant differences were observed between participants with CNP and TMD + CNP for WP (t = -2.80, P  < 0.01, d = -1.06). Post hoc analyses only revealed significant differences between TMD + CNP participants and asymptomatic controls for PPT at extratrigeminal areas. Pearson correlation analyses showed a moderate positive association between symptomatic groups within the WP and STAI ( P  < 0.05) and a moderate negative association between PCS and PPT ( P  < 0.05) at the right tibialis muscle.

Conclusion

TMD + CNP participants had more areas of pain and also showed widespread pain hyperalgesia. Both groups of participants had psychological factors positively associated with STAI and WP; further, PCS and the PPT at the extratrigeminal region were negatively associated with each other in both groups, except for the left tibialis in the TMD + CNP group.

Injection Therapy for Headache and Facial Pain

Peripheral nerve blocks are an increasingly viable treatment option for selected groups of headache patients, particularly those with intractable headache or facial pain. Greater occipital nerve block, the most widely used local anesthetic procedure in headache conditions, is particularly effective, safe, and easy to perform in the office. Adverse effects are few and infrequent. These procedures can result in rapid relief of pain and allodynia, and effects last for several weeks or months. Use of nerve block procedures and potentially onabotulinum toxin therapy should be expanded for patients with intractable headache disorders who may benefit, although more studies are needed for efficacy and clinical safety.

Greater occipital nerve block in the treatment of triptan-overuse headache: A randomized comparative study

OBJECTIVES

This study aims to investigate the efficiency of a single and repeated greater occipital nerve (GON) block using lidocaine in the treatment of triptan-overuse headache (TOH), whose importance has increased lately.

MATERIALS AND METHODS

In the study, 105 consecutive subjects diagnosed with TOH were evaluated. The subjects were randomized into three groups. In Group 1 (n=35), only triptan was abruptly withdrawn. In Group 2 (n=35), triptan was abruptly withdrawn and single GON block was performed. In Group 3 (n=35), triptan was abruptly withdrawn and three-stage GON block was performed. All patients were injected bilaterally with a total amount of 5 cc 1% lidocaine in each stage. During follow-up, the number of headache days per month, the severity of pain (VAS), the number of triptans used, and hsCRP and IL-6 levels were recorded three times; in the pretreatment period, in the second month post-treatment, and in the fourth month post-treatment. They were then compared.

RESULTS

There was a statistically significant difference in the post-treatment fourth month in comparison with the pretreatment period in Group 3 (P<.05). Compared to Group 1, the number of headache days, VAS, and decrease in triptan need in Group 3 was statistically significant compared to Group 2 (P<.05). Compared to pretreatment, in the fourth month post-treatment, both hsCRP and IL-6 levels were lower only in Group 3 (P<.05).

CONCLUSIONS

We are of the opinion that repeated GON block in addition to the discontinuation of medication has significant efficacy for TOH cases.