Influence of greater occipital nerve block on pain severity in migraine patients: A systematic review and meta-analysis

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.

Morphological features of the greater occipital nerve and its possible importance for interventional procedures

Being one of the most prevalent neurological symptoms, headaches are burdensome and costly. Blocks and decompression surgeries of the greater occipital nerve (GON) have been frequently used for migraine, cervicogenic headache, and occipital neuralgia which are classified under headache by International Headache Society. Knowledge of complex anatomy of GON is crucial for its decompression surgery and block. This study was performed to elucidate anatomical features of this nerve in detail. Forty-one cadavers were dissected bilaterally. According to its morphological features, GON was classified into four main types that included 18 subtypes. Moreover, potential compression points of the nerve were defined. The number of branches of the GON up to semispinalis capitis muscle and the number of its branches that were sent to this muscle were recorded. The most common variant was that the GON pierced the aponeurosis of the trapezius muscle, curved around the lower edge of the obliquus capitis inferior muscle, and was loosely attached to the obliquus capitis inferior muscle (Type 2; 61 sides, 74.4%). In the subtypes, the most common form was Type 2-A (44 sides, 53.6%), in which the GON pierced the aponeurosis of each of the trapezius muscle and fibers of semispinalis muscle at one point and there was a single crossing of the GON and occipital artery. Six potential compression points of the GON were detected. The first point was where the nerve crossed the lower border of the obliquus capitis inferior muscle. The second and third points were at its piercing of the semispinalis capitis muscle and the muscle fibers/aponeurosis of the trapezius, respectively. Fourth, fifth, and sixth compression points of GON were located where the GON and occipital artery crossed each other for the first, second, and third times, respectively. On 69 sides, 1-4 branches of the GON up to the semispinalis capitis muscle were observed (median = 1), while 1-4 branches of GON were sent to the semispinalis capitis muscle on 67 sides (median = 1). The novel anatomical findings described in this study may play a significant role in increasing the success rate of invasive interventions related with the GON.

Relative Pain Reduction and Duration of Nerve Block Response Predict Outcomes in Headache Surgery: A Prospective Cohort Study

BACKGROUND

Experts agree that nerve block (NB) response is an important tool in headache surgery screening. However, the predictive value of NBs remains to be proven in a prospective fashion.

METHODS

Pre-NB and post-NB visual analogue pain scores (0 to 10) and duration of NB response were recorded prospectively. Surgical outcomes were recorded prospectively by calculating the Migraine Headache Index (MHI) preoperatively and postoperatively at 3 months, 12 months, and every year thereafter.

RESULTS

The study population included 115 patients. The chance of achieving MHI percentage improvement of 80% or higher was significantly higher in subjects who reported relative pain reduction of greater than 60% following NB versus less than or equal to 60% [63 of 92 (68.5%) versus 10 of 23 (43.5%); P = 0.03]. Patients were more likely to improve their MHI 50% or more with relative pain reduction of greater than 40% versus 40% or less [82 of 104 (78.8%) versus five of 11 (45.5%); P = 0.01]. In subjects with NB response of greater than 15 days, 10 of 13 patients (77.0%) experienced MHI improvement of 80% or greater. Notably, all of these patients (100%) reported MHI improvement of 50% or greater, with mean MHI improvement of 88%. Subjects with a NB response of 24 hours or more achieved significantly better outcomes than patients with a shorter response (72.7% ± 37.0% versus 46.1% ± 39.7%; P = 0.02). However, of 14 patients reporting NB response of less than 24 hours, four patients had MHI improvement of 80% or greater, and seven, of 50% or greater.

CONCLUSIONS

Relative pain reduction and duration of NB response are predictors of MHI improvement after headache surgery. NBs are a valuable tool to identify patients who will benefit from surgery.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Occipital Nerve Block Compared With Acetaminophen and Caffeine for Headache Treatment in Pregnancy: A Randomized Controlled Trial

OBJECTIVE

To evaluate the efficacy of occipital nerve block compared with standard care , defined as acetaminophen with caffeine, for treatment of acute headache in pregnancy.

METHODS

We conducted a single-center, unblinded, parallel, randomized controlled trial of pregnant patients with headache and pain score higher than 3 on the visual rating scale. Patients with secondary headache, preeclampsia, or allergy or contraindication to study medications were excluded. Participants were randomized to occipital nerve block or standard care (oral 650 mg acetaminophen and 200 mg caffeine). Crossover treatment was given at 2 hours and second-line treatment at 4 hours to those with worsening visual rating scale score or visual rating scale score higher than 3. The primary outcome was headache improvement to a visual rating scale score of 3 or lower within 2 hours of initial therapy. Secondary outcomes included serial visual rating scale scores, receipt of crossover or second-line therapy, patient satisfaction, and perinatal outcomes. Outcomes were assessed in an intention-to-treat analysis. We estimated that a sample of 62 would provide 80% power to detect a difference from 85% to 50% between groups.

RESULTS

From February 2020 to May 2022, 62 participants were randomized to occipital nerve block (n=31) or standard care (n=31). Groups were similar except payer status. The primary outcome, headache improvement to visual rating scale score of 3 or lower, was not significantly different between groups (64.5% vs 51.6%, P =.30). The occipital nerve block group experienced lower median [interquartile range] visual rating scale scores at 1 hour (2 [0-5] vs 6 [2-7], P =.014), and more patients in the occipital nerve block group had visual rating scale scores of 3 or lower at 1 hour. Among patients receiving crossover treatment at 2 hours, the standard care group had a significantly lower visual rating scale score 1 hour after crossover to occipital nerve block than the occipital nerve block group receiving crossover to standard care ( P =.028). There were no significant differences in second-line treatment, refractory headache, satisfaction, or complications. Patients receiving occipital nerve block delivered earlier (36.6 weeks vs 37.8 weeks), but preterm birth did not differ between groups.

CONCLUSION

Occipital nerve block is an effective and quick-acting treatment option for acute headache in pregnancy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT03951649.

Greater occipital nerve block in the treatment of headaches. Review of evidence

INTRODUCTION

Peripheral nerve blocks have been a common treatment for multiple headaches. By far, the greater occipital nerve block is the most used and with the stronger body of evidence in routine clinical practice.

METHODS

We searched Pubmed Meta-Analysis/Systematic Review, in the last 10 years. Of these results, meta-analyses, and in the absence of these systematic reviews, assessing Greater Occipital Nerve Block in headache has been selected for review.

RESULTS

We identified 95 studies in Pubmed, 13 that met the inclusion criteria.

CONCLUSION

Greater occipital block is an effective and safe technique, easy to perform and which has shown its usefulness in migraine, cluster headache, cervicogenic headache and Post-dural puncture headache. However, more studies are needed to clarify its long-term efficacy, its place in clinical treatment, the possible difference between different anaesthetics, the most convenient dosage and the role of concomitant use of corticosteroids.

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.

Regional Anesthesia in the Emergency Department: an Overview of Common Nerve Block Techniques and Recent Literature

Purpose of Review

This review seeks to discuss the use of RA in the ED including benefits of administration, types of RA by anatomic location, complications and management, teaching methods currently in practice, and future applications of RA in the ED.

Recent Findings

The early use of RA in pain management may reduce the transition of acute to chronic pain. Multiple plane blocks have emerged as feasible and efficacious for ED pain complaints and are now being safely utilized.

Summary

Adverse effects of opioids and their potential for abuse have necessitated the exploration of substitute therapies. Regional anesthesia (RA) is a safe and effective alternative to opioid treatment for pain in the emergency department (ED). RA can manage pain for a wide variety of injuries while avoiding the risks of opioid use and decreasing length of stay when compared to other forms of analgesia and anesthesia, without compromising patient satisfaction.

Nonsurgical Treatment of Neuralgia and Cervicogenic Headache: A Systematic Review and Meta-analysis

Background:

Extracranial compression of peripheral sensory nerves is one of many origins of chronic headaches. Identifying these patients can be difficult, and they are often diagnosed with neuralgia or cervicogenic headache. The recent literature provides the outcomes of surgical decompression in patients with these headaches. This study aimed to give an overview of the current literature on the nonsurgical treatment options and to evaluate the effectiveness of these treatments in patients with neuralgia and cervicogenic headache.

Methods:

Databases were searched to identify all published clinical studies investigating nonsurgical treatment outcomes in patients with neuralgia or cervicogenic headaches. Studies that reported numerical pain scores, nonnumerical pain scores, headache-free days, or the number of adverse events after nonsurgical treatment were included.

Results:

A total of 22 articles were included in qualitative analysis. The majority of studies included patients who received injection therapy. Treatment with oral analgesics achieved good results in only 2.5% of the patients. Better outcomes were reported in patients who received local anesthetics injection (79%) and corticosteroid injection (87%). Treatment with botulinum toxin injection yielded the highest percentage of good results (97%; 95% CI, 0.81–1.00). The duration of headache relief after injection therapy varied from 30 minutes to 5 months.

Conclusions:

The nonsurgical treatment of patients with neuralgia or cervicogenic headache is challenging. Injection therapy in patients with these types of headaches achieved good pain relief but only for a limited time. Surgical decompression may result in long-lasting pain relief and might be a more sustainable treatment option.

Greater occipital nerve block for chronic migraine patients: A meta-analysis

INTRODUCTION

Greater occipital nerve block (GONB) is a minimally invasive procedure frequently used in patients with chronic migraine (CM); however, the quality of the evidence supporting its use is still unknown. Therefore, we aimed to conduct a systematic review, meta-analysis and quality assessment of GONB local anaesthetics combined or not with corticosteroids to prevent CM.

METHODS

We searched Medline, Scopus and Web of Science up to October 2020. We included randomized control trials (RCT) and observational studies assessing GONB without language restrictions. Two researchers selected the studies, extracted the data and evaluated the risk of bias independently. The primary outcomes measured to assess efficacy were the change from baseline in the intensity and frequency of headache in the intervention group compared to placebo at a onetime point. We performed a meta-analysis with random effect models, and we evaluated random errors with trial sequential analysis (TSA). We assessed the risk of bias (ROB) with the ROB2 tool and the certainty of the evidence with GRADE.

RESULTS

We identified 2864 studies in the databases and included three RCTs for quantitative synthesis. Most ROB assessments were 'high risk' or 'some concerns'. GONB reduced the intensity of headaches at the end of the first month (MD: -1.35, 95% CI: -2.12 to -0.59) and the second month (MD: -2.10, CI 95%: -2.94 to -1.26) as well as the frequency of headaches (first month: MD: -4.45 days, 95% CI: -6.56 to -2.34 days; second month: MD: -5.49, 95% CI -8.94 to -2.03 days). Corticosteroids did not show a significant decrease in the frequency of headaches during the first month of treatment (MD: -1.1 days, 95% CI: -4.1 to 1.8, p = .45). Included trials reported similar adverse events between groups. The exploratory TSA showed inconclusive results. Overall, the quality of the evidence was very low because of the substantial risk of bias and imprecision.

CONCLUSION

The limited evidence available shows that GONB with local anaesthetics could reduce headache frequency and intensity compared to placebo, while adding corticosteroids did not show additional benefits. GONB was safe with a similar number of minor adverse events. However, our confidence in these estimates is very low since the evidence is based on a few trials, with a small sample size and a significant risk of bias. In addition, the exploratory TSA was inconclusive, so we need larger and specific trials.

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.

Efficacy and tolerability of combination treatment of topiramate and greater occipital nerve block versus topiramate monotherapy for the preventive treatment of chronic migraine: A randomized controlled trial

OBJECTIVE

To compare the efficacy and tolerability of combination treatment of topiramate and greater occipital nerve block to topiramate monotherapy in adult chronic migraine patients.

BACKGROUND

Options for the preventive treatment of chronic migraine are limited and costly. Combination treatments do not have an evidence base yet.

METHODS

This was a parallel group, 3 arms with 1:1:1 allocation ratio randomized controlled study in consecutive adult chronic migraine patients attending Headache Clinic in a tertiary care hospital. Patients received either topiramate monotherapy 100 mg/day (group A), or topiramate plus greater occipital nerve block with 40 mg lidocaine (2%) and 80mg (2 ml) methylprednisolone as the first injection followed by monthly injections of lidocaine for the next 2 months (group B) or topiramate plus greater occipital nerve block with 40 mg lidocaine (2%) injections monthly for 3 months (group C). The primary endpoint was the mean change in monthly migraine days at Month 3. Multiple secondary endpoints were assessed that included among others, achievement of ≥50% reduction in mean monthly headache days compared to baseline at Month 3 and assessment for any adverse events.

RESULTS

One hundred and twenty-five patients were randomized; 41 to group A, 44 to group B, and 40 to group C. Efficacy assessments were done for 121 patients. Patients receiving combination treatment of topiramate and greater occipital nerve block with steroids and lidocaine and greater occipital nerve block with only lidocaine compared to topiramate monotherapy showed greater reductions in monthly migraine days at Month 3 (-9.6 vs -7.3 days; p = 0.003) and (-10.1 vs -7.3 days; p < 0.001) respectively. Greater proportion of patients in both the combination treatment groups (added greater occipital nerve block with and without steroid) achieved ≥50% reduction in mean monthly headache days [71.4% vs 39%; OR (95% CI) 3.9(1.6-9.8); p = 0.004] and [62.4% vs 39%; OR (95% CI) 2.7(1.1-6.7); p = 0.034] respectively, compared to those receiving topiramate monotherapy. Adverse effects between the groups were comparable although patients receiving combination treatment with added greater occipital nerve block reported transient adverse effects like post-injection dizziness, local site swelling, and pain. No serious adverse event was reported.

CONCLUSION

Combination treatments of topiramate with monthly injections of greater occipital nerve block were more effective in reducing monthly migraine days in chronic migraine than topiramate monotherapy at Month 3. Combination treatments were well tolerated.

Efficacy of greater occipital nerve block for pain relief in patients with postdural puncture headache: A meta-analysis

BACKGROUND

This study aimed at assessing the therapeutic effectiveness of greater occipital nerve block (GONB) against postdural puncture headache (PDPH).

METHODS

Studies investigating analgesic effects of GONB against PDPH in adults were retrieved from the MEDLINE, EMBASE, Google scholar, and Cochrane central databases from their inception dates to May, 2021. Pain score at postprocedural 24 hours was the primary endpoint, while secondary endpoints were pain score at postprocedural 1 hour and 12 hours as well as the risk of intervention failure.

RESULTS

Of the 7 studies (randomized controlled trials [RCTs], n = 4; non-RCTs, n = 3) that recruited 275 patients, 2 investigated female patients undergoing cesarean section and the other 5 were conducted in both obstetric and nonobstetric settings. Pooled results showed a lower mean pain score at 24 hours (i.e., primary outcome) (mean difference [MD] = -2.66, 95%: CI: -3.98 to -1.33, P < .001; I2 = 97%, 6 studies), 1 hour (MD = -4.23, 95% confidence interval [CI]: -5.08 to -3.37, P < .00001; I2 = 86%, 5 studies), and 6 hours (MD = -2.78, 95% CI: -4.99 to -0.57, P = .01; I2 = 98%, 4 studies) in patients with GONB compared to those without. Trial sequential analysis supported the robustness of evidence at postprocedural 24 hours. The use of GONB also decreased the risk of intervention failure (relative ratio [RR] = 0.4, 95% CI: 0.19 to 0.82, P = .01; I2 = 96%, 6 studies, 277 patients).

CONCLUSION

Our results suggested a therapeutic effect of greater occipital nerve block against postdural puncture headache up to postprocedural 24 hours. Further large-scale studies are warranted to evaluate its therapeutic benefit beyond the acute stage.

Peripheral Nerve Stimulation for Chronic Pain: A Systematic Review of Effectiveness and Safety

Peripheral nerve stimulation (PNS) was the first application of neuromodulation. Widespread application of PNS was limited by technical concerns. Recent advances now allow the percutaneous placement of leads with ultrasound or fluoroscopic guidance, while the transcutaneous powering of these leads removes the need for leads to cross major joints. This systematic review was written to assess the current status of high-quality evidence supporting the use of PNS for pain conditions treated by interventional pain physicians. The available literature on PNS, limited to conditions treated by interventional pain physicians, was reviewed and the quality assessed. Literature from 1966 to June 2021 was reviewed. The outcome measures were pain relief and functional improvement. One hundred and two studies were identified. Five randomized controlled trials (RCT) and four observational studies, all case series, met the inclusion criteria. One RCT was of high quality and four were of moderate quality; all four case series were of moderate quality. Three of the RCTs and all four case series evaluated peripheral nerve neuropathic pain. Based upon these studies, there is level II evidence supporting the use of PNS to treat refractory peripheral nerve injury. One moderate-quality RCT evaluated tibial nerve stimulation for pelvic pain, providing level III evidence for this indication. One moderate-quality RCT evaluated surgically placed cylindrical leads for cluster headaches, providing level III evidence for this indication. The evidence suggests that approximately two-thirds of patients with peripheral neuropathic pain will have at least 50% sustained pain relief. Adverse events from PNS are generally minor. A major advantage of PNS over spinal cord stimulation is the absence of any risk of central cord injury. The study was limited by the paucity of literature for some indications. No studies dealt with joint-related osteoarthritic pain.

Effectiveness of Peripheral Nerve Blocks for the Treatment of Primary Headache Disorders: A Systematic Review and Meta-Analysis

STUDY OBJECTIVE

Primary headache disorders are prevalent and account for 2% of all emergency department visits. Current treatment options are effective; however, time to pain relief is suboptimal. Alternatives such as peripheral nerve blocks have shown promising results. The objective of this systematic review is to examine the effectiveness of peripheral nerve blocks for timely pain relief.

METHODS

We searched Ovid MEDLINE, EMBASE, Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials and included randomized controlled trials comparing peripheral nerve blocks to placebo or active therapy. The primary outcome was pain within 120 minutes. Secondary outcomes were pain after 120 minutes, adverse events, need for rescue medications, and relapse of headache. Two reviewers screened and extracted data independently; mean differences (MDs) were calculated, and results were pooled using a random-effects model.

RESULTS

Eleven studies met our eligibility criteria (n=860), of which 9 were included in the meta-analysis. Pain scores were significantly lower in patients treated with peripheral nerve blocks than with placebo at 15 minutes (MD: -1.17; 95% confidence interval: -1.82 to -0.51) and 30 minutes (MD: -0.99; 95% confidence interval: -1.66 to -0.32), and no serious adverse events were reported. Pain scores for peripheral nerve blocks versus active therapy and secondary outcomes were not pooled due to clinical heterogeneity.

CONCLUSION

Our review shows peripheral nerve blocks are effective as a rapid treatment option when compared to placebo; however, we were unable to assess effectiveness against standard treatment. Emergency physicians should consider peripheral nerve blocks as an adjunct therapy for patients with primary headache disorders.

Percutaneous Interventional Strategies for Migraine Prevention: A Systematic Review and Practice Guideline

OBJECTIVE

To systematically evaluate the efficacy and effectiveness of percutaneous interventional treatments for prevention of migraine through a qualitative and (when possible) quantitative analysis.

METHODS

An expert panel was asked to develop recommendations for the multidisciplinary preventive treatment of migraine, including interventional strategies. The committee conducted a systematic review and (when evidence was sufficient) a meta-analytic review using GRADE criteria and the modified Cochrane risk of bias analysis available in the Covidence data management program. Clinical questions addressed adults with migraine who should be offered prevention. Examined outcomes included headache days, acute medication use, and functional impairment. Acute management of migraine was outside the scope of this guideline.

RESULTS

The committee screened 1195 studies and assessed 352 by full text, yielding 16 randomized controlled trials that met inclusion criteria.

RECOMMENDATIONS/CONCLUSIONS

As informed by evidence related to the preselected outcomes, adverse event profile, cost, and values and preferences of patients, onabotulinumtoxinA received a strong recommendation for chronic migraine prevention and a weak recommendation against use for episodic migraine prevention. Greater occipital nerve blocks received a weak recommendation for chronic migraine prevention. For greater occipital nerve block, steroid received a weak recommendation against use vs local anesthetic alone. Occipital nerve with supraorbital nerve blocks, sphenopalatine ganglion blocks, cervical spine percutaneous interventions, and implantable stimulation all received weak recommendations for chronic migraine prevention. The committee found insufficient evidence to assess trigger point injections in migraine prevention and highly discouraged use of intrathecal medication.

Temperature-Mediated Nerve Blocks in the Treatment of Pain

PURPOSE OF REVIEW

Analgesic hot and cold temperatures have been used for both conservative and ablative therapies for millennia. There are well-known locoregional neurovascular changes associated with the application of heat or ice in the literature and in practice. The oscillation between heat and cold has recently been identified as a synergistic mechanism of action with early translational results in humans.

RECENT FINDINGS

Recent mechanistic work in the feline model has demonstrated that a reliable, reversible nerve block can be achieved within a temperature range that is non-destructive (15-45°C). The underlying mechanism is a newly described hysteresis in the responsiveness of peripheral nerves to alternating thermal stimuli resulting in nerve blockade. Recently presented feasibility data reports positive results in subjects with occipital pain and peripheral scar pain in terms of pain and associated symptom improvement. Temperature-mediated changes in pain and sensation have been observed for hot and cold applications at a variety of temperatures. Recent insights into the synergy between preheating followed by cooling resulting in peripheral nerve fiber block has potential in a variety of conditions in which peripheral nerve etiology is noted. Recent findings in chronic headache patients report decreased pain and symptom improvement. Further studies are ongoing to understand the indications for this novel therapy.

Comparison of greater occipital nerve and greater occipital nerve + supraorbital nerve block effect in chronic medication overuse headache

Background /aim

In this study, we aimed to compare the efficacy of greater occipital nerve (GON) block alone and GON combined with supraorbital nerve (SON) block in the treatment of medication overuse headache (MOH).

Material and methods

82 patients were divided into two groups: 41 patients were administered bilateral GON block while the other 41 patients GON + SON block. Nerve blocks were administered every 10 days for a total of 5 sessions. After each administration and 20 days after the last injection, information on pre and post treatment numerical rating scale (NRS) score, number of painful days, analgesic intake, duration of pain were collected.

Results

The decrease in headache evaluation parameters was similar in both groups after the block. The NRS scores in the GON and GON + SON groups before the treatment was (8.2 ± 0.7, 8.5 ± 0.7), the number of painful days in a month was (21.4 ± 6.9, 21.2 ± 4.6 days), the number of analgesics taken monthly was (45 ± 25.6, 47.5 ± 29.9), the duration of pain was (44.9 ± 24.6, 41.7 ± 22.8 h), respectively. On the 60th day of treatment, the NRS scores in the GON and GON + SON groups were found to be (6.8 ± 2.5, 4.8 ± 2.3), the number of painful days in a month was (4.2 ± 3.3, 2.2 ± 1.5), respectively. The number of monthly analgesic consumption was (4.4 ± 3.8, 0.9 ± 1.2), and the duration of pain was (28.4 ± 19.3, 19.4 ± 16.1 h).

Conclusion

This study showed significant reductions in headache parameters in both groups. However, NRS score, analgesic intake, number of painful days, and pain duration significantly better improved in the GON block added SON block group.

Role of Greater Occipital Nerve Block in Headache Disorders: A Narrative Review

Background

The proximity of sensory neurons in the upper cervical spinal cord to the trigeminal nucleus caudalis (TNC) neurons and the convergence of sensory input to TNC neurons from both cervical and trigeminal fibers underscore the rationale of using greater occipital nerve block (GON-block) for acute and preventive treatment in various headache disorders.

Objective

The aim of this study was to critically review the existing literature regarding the safety and efficacy of GON-block in various headache disorders.

Methods

We searched the eligible studies in English by searching in PubMed till December 31, 2020 for randomized controlled trials (RCTs), observational studies, open-label studies, case series, and case reports on the efficacy and the safety of GON-block for the treatment of headache disorders using the keywords "greater occipital nerve block", "headache" and "treatment". Studies using combination of GON-block and other peripheral nerve blocks (PNBs) and C2/C3 blocks were excluded.

Results

Seventy-two eligible studies were reviewed. Based on RCTs and open-label studies, good evidence of the efficacy of GON-block was found for migraine, cluster headache (CH), post-dural puncture headache (PDPH), cervicogenic headache (CGH), and occipital neuralgia (ON). The analgesic effect of GON-block outlasted its anesthetic effect by days to weeks. Evidence for acute and short-term (transitional) treatment was more robust than for long-term prevention. GON-block was found to be safe and the treatment-emergent adverse effects (TEAEs) were generally mild and transient.

Conclusion

GON-block is a useful modality of treatment in various headache disorders because of many attractive features such as its early effect in reducing the severity of pain, sustained effect following a single injection, easy technique, minimum invasiveness, minimum TEAE, no drug-to-drug interactions, and negligible cost.

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.

Feasibility study of greater occipital nerve blocks by focused ultrasound - an animal study

OBJECTIVE

Greater occipital nerve (GON) block may provide substantial relief for headache in the occipital location. This study tested the feasibility of focused ultrasound (FUS) to induce the conduction block of GONs in rats.

APPROACH

For in vitro experiments, the nerve was dissected and cut from C2 to the site near the ear of the rats and preserved in Ringer's solution. Pulsed FUS was used for the block, and sensory action potentials were recorded in the GON. For in vivo experiments, the GONs of the rats were surgically exposed for precise ultrasonic treatment. All data are expressed as the mean ± the standard deviation.

MAIN RESULTS

A single ultrasonic treatment temporarily suppressed the amplitude of action potentials of the in vitro nerves to 42 ± 14% of the baseline values, and the time to recovery was 55 min. The in vivo results showed that FUS acutely inhibited the amplitude of action potentials to 41 ± 8% of the baseline value in rat GONs, and the time to recovery was 67 min. Histological examination revealed no appreciable changes in the nerve morphology caused by FUS. Therefore, FUS reversibly blocked the conduction of the rat GON when the sonication parameters were appropriate.

SIGNIFICANCE

Noninvasive FUS may be a novel treatment paradigm for occipital headache by blocking the occipital nerve, and the procedure is repeatable if indicated.

Role of greater occipital nerve block for preventive treatment of chronic migraine: A critical review

Objective:

The aim of this study is to critically analyze the evidence of the efficacy and safety of greater occipital nerve (GON) block for the preventive treatment of chronic migraine (CM).

Background:

A rigorous scientific assessment of efficacy and safety of the GON block for preventive treatment in CM is not available. This critical review was undertaken for this purpose.

Methods:

References for this review were identified by searches of articles published in the English language in PubMed between 1969 and April 15, 2020 using “greater occipital nerve block,” “chronic migraine,” “migraine,” “headache,” and “treatment” as keywords.

Results:

Out of potential 532 articles, 9 open-label and 4 placebo-controlled trials that studied the role of GON block for prevention of CM were identified and reviewed. Open-label trials reported a reduction of headache severity and frequency in 35–68% of patients. The beneficial effect of a single block lasted up to 4 weeks. Randomized controlled trials (RCTs) used varied methodology and techniques of GON block and the outcomes were reported at different time points. A single RCT showed a beneficial effect of the GON block at 1 week. However, the GON block was found to be safe and well tolerated.

Conclusion:

Long-term efficacy of GON block in CM shall need further well-designed RCTs using standardized methodology. This study, in addition, reviewed the limitations and uncertainties regarding the technique and methods of use of GON block in CM.

A Randomized, Double-Dummy, Emergency Department-Based Study of Greater Occipital Nerve Block With Bupivacaine vs Intravenous Metoclopramide for Treatment of Migraine

BACKGROUND

Greater occipital nerve blocks (GONB) are used increasingly to treat acute migraine.

OBJECTIVE

We conducted a randomized controlled trial to determine whether GONB was as effective as intravenous metoclopramide for migraine.

METHODS

This was a double-dummy, double-blind, parallel-arm, non-inferiority study conducted in 2 emergency departments (EDs). Patients with migraine of moderate or severe intensity were randomized to receive bilateral GONB with each side administered 3 mL of bupivacaine 0.5% or metoclopramide 10 mg IV, the putative standard of care. The primary outcome was improvement in pain on a 0-10 scale between time 0 and 1 hour later. To reject the null hypothesis that metoclopramide would be more efficacious in relieving pain, we required that the lower limit of the 95% CI for the difference in pain improvement between those randomized to GONB vs those randomized to metoclopramide be >-1.3, a validated minimum clinically important difference. Secondary outcomes included sustained headache relief, defined as achieving and maintaining for 48 hours a headache level of mild or none without the use of additional analgesic medication, and the use of rescue medication in the ED.

RESULTS

Over a 2.5-year study period, 1358 patients were screened for participation and 99 were randomized, 51 to GONB and 48 to metoclopramide. All of these patients were included in the primary analysis. Patients who received the GONB reported mean improvement of 5.0 (95% CI: 4.1, 5.8) while those who received metoclopramide reported a larger mean improvement of 6.1 (95% CI: 5.2, 6.9). The 95% CI for the between group difference of -1.1 was -2.3, 0.1. Sustained headache relief was reported by 11/51 (22%) GONB and 18/47 (38%) metoclopramide patients (95% CI for rounded difference of 17%: -1, 35%). Of the 51 GONB patients, 17 (33%) required rescue medication in the ED vs 8/48 (17%) metoclopramide patients (95% CI for rounded difference of 17%: 0, 33%). An adverse event was reported by 16/51 (31%) GONB patients and 18/48 (38%) metoclopramide patients (95% CI for (rounded) difference of 6%: -13, 25%).

CONCLUSION

GONB with bupivacaine was not as efficacious as IV metoclopramide for the first-line treatment of migraine in the ED.

Predicting the outcome of the greater occipital nerve block - an observational study on migraine patients with and without musculoskeletal cervical impairment

BACKGROUND AND OBJECTIVE

The importance of neck pain and the trigeminocervical complex in migraine is of high pathophysiological interest since a block to the greater occipital nerve is more effective for some primary headaches than others. This observational study hypothesised that the response to manual palpation of the upper cervical spine predicts the efficacy of the greater occipital nerve-block.

METHODS

We divided patients, scheduled by a neurologist to receive a greater occipital nerve-block to reduce their migraine symptoms, into three groups: Patients with no pain response to manual palpation of the neck, patients with local pain, and those with referred pain to the head. Primary outcome was the percentage change in headache frequency. Additionally, items from the quantitative sensory testing protocol were included.

RESULTS

Eighty-seven chronic migraine patients were recruited consecutively from a specialised outpatient clinic and 71 were included for analyses and stratified into the three groups: No pain (n = 11), local pain (n = 28), and referred pain to the head (n = 32). Overall, patients experienced a reduction of 1.9 headache days per month (SD 3.4, p < 0,0001). The groups differed significantly in the percentage change of headache frequency (p = 0.041) with the "no pain" group showing the largest reduction. The pressure-pain-threshold over C2 and headache on the day of the intervention influenced the outcome significantly (R² 0,27, p = 0,00078). No serious adverse events occurred. Sixty-five percent of the patients had headaches during the examination. The groups did not differ regarding the distribution of patients with neck-pain in absence of migraine at baseline (p = 0.618).

CONCLUSION

Patients that were less sensitive to palpation in the cervical region and headache-free on the day of the intervention improved more after the greater occipital nerve-block.Registration: Registered a priori at the German Clinical Trials Register (DRKS00015995).

Prophylactic Electroacupuncture on the Upper Cervical Segments Decreases Neuronal Discharges of the Trigeminocervical Complex in Migraine-Affected Rats: An in vivo Extracellular Electrophysiological Experiment

Purpose

This rat experiment aims to demonstrate the efficacy of electrical acupuncture in preventing migraine attacks by stimulating the acupoint GB20.

Introduction

Migraine, which takes 2ed at level four causes of GBD’s disease hierarchy, becomes a public health issue. It is important for physicians to supplement their knowledge of its treatment and consider alternative methods of therapy, such as acupuncture. However, the neurobiological and pathophysiological mechanisms of this prophylactic effect were unclear. The trigeminocervical complex is thought to be an important relay station in migraine pathophysiology as the key nuclei of the trigeminovascular system and the brainstem descending pain modulation system.

Methods

There were six groups involved in this study: control, model, electroacupuncture, non-acupoint electroacupuncture, saline+electroacupuncture and saline+non-acupoint electroacupuncture. We injected saline or inflammatory soup into dura mater to induce control or migraine in the rats. The mechanical pain threshold and the single-cell extraneural neurophysiology of the C1 spinal dorsal horn neurons in the trigeminocervical complex were detected.

Results

Pre-electroacupuncture could significantly increase the mechanical pain threshold of the periorbital region receptive field of the trigeminal nerve and decrease the discharges of neurons in the trigeminocervical complex. Acupuncture also reversed the abnormal skin pain response of the periorbital region receptive field of the trigeminal nerve caused by low-intensity stimulation.

Discussion

We believe that our study makes a significant contribution to the literature because it is the first of its kind to use GB20 to provide relief from migraine attacks and mechanical cephalic cutaneous hypersensitivity by regulating the neuronal discharge from trigeminocervical complex.

Physical therapy and migraine: musculoskeletal and balance dysfunctions and their relevance for clinical practice

BACKGROUND

Migraine is a primary headache with high levels of associated disability that can be related to a variety of symptoms and comorbidities. The role of physical therapy in the management of migraine is largely unknown. Therefore, the aim of this review is to highlight and critically discuss the current literature and evidence for physical therapy interventions in individuals with migraines.

METHODS

A narrative review of the literature was performed.

RESULTS

Physical therapists assessing and treating patients with migraine should focus on two primary aspects: (1) musculoskeletal dysfunctions, and (2) vestibular symptoms/postural control impairment. Signs and symptoms of musculoskeletal and/or vestibular dysfunctions are prevalent among individuals with migraines and different disability levels can be observed depending on the presence of aura or increment of the migraine attacks.

CONCLUSION

A proper physical examination and interview of the patients will lead to a tailored treatment plan. The primary aim regarding musculoskeletal dysfunctions is to reduce pain and sensitization, and physical therapy interventions may include a combination of manual therapy, exercise therapy, and education. The aim regarding postural control impairment is to optimize function and reduce vestibular symptoms, and interventions should include balance exercises and vestibular rehabilitation. However, consistent evidence of benefits is still lacking due to the lack of and therefore need for tailored and pragmatic clinical trials with high methodological quality.

Evaluation of Occipital Nerve Blocks for Acute Pain Relief of Migraines

Migraines are a debilitating neurological disease affecting as many as 1 of 6 adults in the United States. Occipital nerve block, consisting of a local anesthetic and/or corticosteroid, has shown to be an effective treatment for the management of migraines. Occipital nerve block has been reported to reduce migraine pain scores, frequency, and duration. We aimed to evaluate the impact of occipital nerve block for acute pain relief in patients with migraines. This was a single-center retrospective observational study conducted at a 1162-bed academic medical center in Gainesville, Florida. Included patients were ≥18 years old, diagnosed with migraine with or without aura, and received at least 1 occipital nerve block. Excluded patients received nerve blocks not specific to the occipital region. The outcomes observed were migraine pain before and after administration within the same initial encounter of receiving an occipital nerve block using a numeric pain rating scale, injection direction, medications used, duration of effect and frequency of additional injections, and adverse reactions. A total of 190 patients met the inclusion criteria, with 63% rating their pain to be 6-8 of 10 prior to an occipital nerve block. After receiving an occipital nerve block, 27% of patients reported significant or immediate relief, and 42% experienced reduced pain scores of 0-2. The majority of injections were bilateral using lidocaine with dexamethasone. Only 3% of patients reported an adverse reaction. Occipital nerve block as adjunctive therapy has shown safety and efficacy in treating patients with migraines, measured by the reduction in pain.

Greater occipital and supraorbital nerve blockade for the preventive treatment of migraine: a single-blind, randomized, placebo-controlled study

OBJECTIVE

Nerve injections have been used for the acute and preventive treatment of migraine in recent decades. Most of these injections focused on greater occipital nerve (GON) blockade. However, few studies were placebo controlled, and only a few of them investigated GON and supraorbital nerve (SON) blockade together. This study aimed to evaluate the efficacy of GON and SON blockade with local anesthetics for the preventive treatment of migraine without aura.

METHODS

Eighty-seven patients diagnosed with migraine without aura were included in the study. Patients were divided randomly. One group was injected with 1% lidocaine, the other group was injected with 0.9% saline. GON and SON injections were done bilaterally. The injections were repeated weekly for 3 weeks. Patients were followed up for 2 months to assess clinical response.

RESULTS

Seventy-one patients completed the study. After 2 months, the number of headache days decreased significantly from 12.8 ± 10.9 to 5.3 ± 7.4, and VAS decreased from 8.3 ± 1.0 to 5.5 ± 1.9 in the blockade group. The number of headache days decreased from 12.4 ± 10.3 to 7.5 ± 7.2 and VAS decreased from 8.2 ± 1.1 to 7.4 ± 1.3 in the placebo group. Response was seen in 65.1% of the patients in the blockade group (65.4% for episodic migraine, 64.7% for chronic migraine) and 28.6% of the patients in the placebo group. The difference was significant.

CONCLUSIONS

The results suggest that GON and SON blockade with lidocaine was more effective than the placebo in the prophylactic treatment of both episodic and chronic migraine.

Current Approach to Undifferentiated Headache Management in the Emergency Department

PURPOSE OF REVIEW

To discuss pharmacological interventions in the emergency department (ED) setting for the management of acute primary headache.

RECENT FINDINGS

Acute headache treatment in the ED has seen an expansion in terms of possible pharmacological interventions in recent years. After a thorough evaluation ruling out dangerous causes of headache, providers should take the patient's history, comorbidities, and prior therapy into consideration. Antidopaminergics have an established role in the management of acute, severe, headache with manageable side-effect profiles. However, recent studies suggest anesthetic and anti-epileptic drugs may play roles in headache treatment in the ED. Current literature also suggest steroids as a promising tool for emergency department clinicians combating the readmission of patients with recurrent headaches. Emergency medicine providers must be cognizant of these traditional and emerging therapies in order to optimize the care of headache patients.

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.

Essential pharmacologic options for acute pain management in the emergency setting

Pain is the root cause for the overwhelming majority of emergency department (ED) visits worldwide. However, pain is often undertreated due to inappropriate analgesic dosing and ineffective utilization of available analgesics. It is essential for emergency providers to understand the analgesic armamentarium at their disposal and how it can be used safely and effectively to treat pain of every proportion within the emergency setting. A ‘balanced analgesia’ regimen may be used to treat pain while reducing the overall pharmacologic side effect profile of the combined analgesics. Channels-Enzymes-Receptors Targeted Analgesia (CERTA) is a multimodal analgesic strategy incorporating balanced analgesia by shifting from a system-based to a mechanistic-based approach to pain management that targets the physiologic pathways involved in pain signaling transmission. Targeting individual pain pathways allows for a variety of reduced-dose pharmacologic options – both opioid and non-opioid – to be used in a stepwise progression of analgesic strength as pain advances up the severity scale. By developing a familiarity with the various analgesic options at their disposal, emergency providers may formulate safe, effective, balanced analgesic combinations unique to each emergency pain presentation.

Nerve blocks in paediatric and adolescent headache disorders

PURPOSE OF REVIEW

Headaches in children and adolescents are common, causing debilitating symptoms in many. Treatment of headache disorders can be complex and standard lifestyle changes as well as oral medications may offer inadequate relief. The purpose of this article is to review the mechanism of action, efficacy and technique of peripheral nerve blocks (PNBs) and the role they play in treating paediatric headache disorders.

RECENT FINDINGS

Evidence for the use of PNBs in youth is limited. However, available studies show evidence of benefit in both primary and secondary headache disorders. Variability exists in the type of block, medication choice, volume infused and frequency of this treatment. There are no serious side effects associated with PNBs.

SUMMARY

PNBs are well tolerated and effective as adjunctive therapy for many disabling paediatric headache disorders. The technique can be easily learned by frontline and specialty practitioners. Prospective placebo-controlled studies are needed to determine how to best maximize PNBs for headache management (i.e. medication choice, timing and so on).

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.

[Dissection and observation of a large unnamed nerve in the posterior cervical triangle]

OBJECTIVE

To characterize the anatomical features of a large unnamed nerve in the posterior cervical triangle and clarify its relationship with the lesser occipital nerve.

METHODS

We dissected 31 adult formalin-fixed cadaver head and neck specimens (62 sides). The lateral cervical region, the anterior cervical region, the sternocleidomastoid region, and the occipital region were dissected to define the anatomical features of the unnamed nerve.

RESULTS

This unnamed nerve was identified in the posterior cervical triangle in 96.8% of the specimens. The main trunk of the nerve had a diameter of about 3 mm with a length of around 10 cm. The nerve arose from the anterior branch of the second cervical nerve (C2, C2-3), entered the posterior cervical triangle at 1-3 cm above the accessory nerve, and continued to ascend along or in parallel with the posterior border of the sternocleidomastoid muscle. It passed between the attachments of the sternocleidomastoid and the trapezius to the occiput and divided into 3-5 branches, which innervated the skin area between the lesser and greater occipital nerves.

CONCLUSIONS

We identified a large unnamed nerve in the posterior cervical triangle, for which we coined the name "long occipital nerve" based on its unique anatomical features. The discovery of this nerve can be important for local surgery and for diagnosis and treatment of related diseases.

Tracking patients with chronic occipital headache after occipital nerve decompression surgery: A case series

BACKGROUND

The therapeutic benefit of nerve decompression surgeries for chronic headache/migraine are controversial.

AIM

To provide clinical characteristics of headache type and treatment outcome of occipital nerve decompression surgery.

METHODS

A retrospective review of clinical records. Inclusion criteria were evidence of chronic occipital headache with and without migrainous features and tenderness of neck muscles, occipital allodynia, and inadequate response to prophylactic drugs.

RESULTS

Surgical decompression of the greater and lesser occipital nerves provided complete and extended (3-6 years) relief of new daily persistent headache in case 3 (46 year old female), and of chronic post-traumatic headache in cases 4 and 6 (35 and 30 year old females, respectively), partial relief of chronic headache/migraine in cases 1 and 2 (41 year old female and 36 year old male), and no relief of episodic (cases 3 and 4) or chronic migraine (case 5, 52 year old male), or chronic tension-type headache (case 7, 31 year old male).

CONCLUSIONS

As a case series, this study cannot test a hypothesis or determine cause and effect. However, the complete elimination of new daily persistent headache and post-traumatic headache, and the partial elimination of chronic headache/migraine in two patients - all refractory to other treatment approaches - supports and justifies the effort to continue to generate data that can help determine whether decompression nerve surgeries are beneficial in the treatment of certain types of chronic headache.

Treating status migrainosus in the emergency setting: what is the best strategy?

INTRODUCTION

Migraine is a disabling primary headache disorder with unknown exact pathomechanism. Status migrainosus (SM) is a complication of migraine (with or without aura), representing an attack that lasts for more than 72 h. There is a paucity of data published with regard to its pathomechanism and therapeutic options.

AREAS COVERED

The authors review the literature on SM from PubMed published between 1999 and January 2018. The authors specifically look at the therapeutic possibilities of SM in the emergency department in patients that have or have not already been treated with serotonergic agents. Additional discussion is given to the rare complications of migraine.

EXPERT OPINION

SM is a devastating condition; therefore, the primary goal is to prevent its development with proper acute and prophylactic migraine medication. If this treatment fails, the patient should be treated in the emergency setting. Due to the severity of the condition, parenteral pharmacotherapy is recommended. However, high-quality randomized trials are lacking. The currently available data suggest the use of intravenous fluids, corticosteroids, magnesium sulfate, anticonvulsive drugs, nonsteroidal anti-inflammatory drugs, antiemetics, and serotonergic agents for the treatment of SM. Still, there is a need for personalized and causal therapy for migraine sufferers.

Use of occipital nerve block in emergency department treatment of status migrainosus

Migraine headaches make up a significant proportion of emergency department visits. There are multiple pharmacologic treatment modalities for migraine abortive therapy; however, these treatments are rarely targeted to the precise area of pain and thus elicit multiple systemic effects. It has been well established in the anesthesia pain literature that occipital nerve blocks can provide not only immediate pain relief from occipital migraines, but can also result in a long-term resolution of occipital migraines. In this case report, we present how an occipital nerve block in the emergency department resulted in immediate and long-lasting resolution of a patient's occipital migraine.

Migraine

Migraine is a chronic paroxysmal neurological disorder characterised by multiphase attacks of head pain and a myriad of neurological symptoms. The underlying genetic and biological underpinnings and neural networks involved are coming sharply into focus. This progress in the fundamental understanding of migraine has led to novel, mechanism-based and disease-specific therapeutics. In this Seminar, the clinical features and neurobiology of migraine are reviewed, evidence to support available treatment options is provided, and emerging drug, device, and biological therapies are discussed.