Expert opinion: greater occipital nerve and other anesthetic injections for primary headache disorders

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.

The Public's Perception of Interventions for Migraine Headache Disorders: A Crowdsourcing Population-Based Study

Background

Migraine disorders are a leading cause of morbidity and decreased economic productivity in the United States among both men and women. As such, it is important to consider patient opinions, and have an accurate representation of the burden and sentiment toward currently available interventions among those suffering from migraines.

Objectives

The aim of the study was to assess patient options regarding adverse outcomes of the various treatment options available for migraine headaches.

Methods

A prospective cross-sectional study of volunteers recruited through an internet crowdsourcing service, Amazon Mechanical Turk©, was conducted. Surveys were administered to collect patient-reported opinions regarding adverse outcomes of both surgical and nonsurgical treatment options for migraine headaches.

Results

The prevalence of migraine headache across all study participants was 15.6% and varied slightly across participant demographics. Individuals ages 35–44 (2.73 migraines per month) experienced the fewest migraine and with the lowest severity. Those individuals ages 45+ experienced the most severe headaches (Visual Analog Scale = 44.23 mm). Additionally, the greatest migraine frequency and severity existed among those households with yearly income of $75,000–$100,000. The lowest injection therapy utility scores were obtained for adverse outcomes of hematoma (47.60 mm) and vertigo (54.40 mm).

Conclusions

Migraine headaches remains a significant problem among the US population, with an overall prevalence of 15.6% (approximately 50 million Americans). Additionally, physicians interesting in offering minimally invasive or surgical treatment for migraine headaches should focus on mitigating patient fears regarding clinical outcomes and cost of care.

Occipital Nerve Blocks in the Emergency Department for Initial Medication-Refractory Acute Occipital Migraines

Migraines are consistently among the top 20 primary coded diagnoses in emergency departments, constituting 4.5% of all chief complaints. In a significant subset of these, pain arises from the occipital region innervated by the greater (GON) and lesser occipital nerve. In this case series, we present three patients with occipital migraines who received GON blockade with 1% lidocaine. The blockade was performed only after first-line treatment with metoclopramide and possibly additional medications as ordered by triage physician, failed to adequately alleviate pain by 40 minutes after medication administration. Patients were contacted a minimum of seven days following treatment. All three patients experienced significant analgesia and relief of symptoms within 15 minutes of blockade and sustained relief through a seven-day follow-up period.

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.

Occipital osteomylelitis and epidural abscess after occipital nerve block: A case report

Occipital neuralgia is a paroxysmal jabbing pain in the distribution of the greater or lesser occipital nerves accompanied by diminished sensation in the affected area. Occipital nerve block is a common diagnostic and therapeutic tool used in the course of occipital neuralgia and is considered a safe treatment with few localized adverse events. Occipital nerve block is also indicated for cervicogenic and cluster headache and is often used as a rescue treatment for headaches not responding to conventional therapies. We describe a case of epidural abscess formation 16 days following occipital nerve block in a patient with no underlying medical conditions. This case report emphasizes the importance of strict aseptic technique to reduce infection rates in patients undergoing this procedure, despite the overall safety of occipital nerve block. Clinicians must remain aware of acute and late complications arising postprocedure for the safe practice of this technique.

Chronic Daily Headache: Mechanisms and Principles of Management

Primary headache is a common malady that is often under-recognized and frequently inadequately managed in spite of the fact that it affects up to 95 % of the population in a lifetime. Many forms of headache, including episodic tension and migraine headaches, if properly diagnosed, are reasonably amenable to treatment, but a smaller, though not insignificant, percent of the population suffer daily from a chronic, intractable form of headache that destroys one's productivity and quality of life. These patients are frequently seen in neurological practices at a point when treatment options are limited and largely ineffective. In the following review, we will discuss mechanisms drawn from recent studies that address the transition from acute to chronic pain that may apply to the transformation from episodic to chronic daily headaches which may offer opportunities for preempting headache transformation.

Bilateral greater occipital nerve block for treatment of post-dural puncture headache after caesarean operations

BACKGROUND

Post-dural puncture headache (PDPH) is an important complication of neuroaxial anesthesia and more frequently noted in pregnant women. The pain is described as severe, disturbing and its location is usually fronto-occipital. The conservative treatment of PDPH consists of bed rest, fluid theraphy, analgesics and caffeine. Epidural blood patch is gold standard theraphy but it is an invasive method. The greater occipital nerve (GON) is formed of sensory fibers that originate in the C2 and C3 segments of the spinal cord and it is the main sensory nerve of the occipital region. GON blockage has been used for the treatment of many kinds of headache. The aim of this retrospective study is to present the results of PDPH treated with GON block over 1 year period in our institute.

METHODS

16 patients who had been diagnosed to have PDPH, and performed GON block after caesarean operations were included in the study. GON blocks were performed as the first treatment directly after diagnose of the PDPH with levobupivacaine and dexamethasone.

RESULTS

The mean VAS score of the patients was 8.75 (±0.93) before the block; 3.87 (±1.78) 10min after the block; 1.18 (±2.04) 2h after the block and 2.13 (±1.64) 24h after the block. No adverse effects were observed.

CONCLUSIONS

Treatment of PDPH with GON block seems to be a minimal invasive, easy and effective method especially after caesarean operations. A GON block may be considered before the application of a blood patch.

Sonographic evaluation of the greater occipital nerve in unilateral occipital neuralgia

OBJECTIVES

Occipital neuralgia is a headache that may result from greater occipital nerve entrapment. Entrapped peripheral nerves typically have an increase in cross-sectional area. The purpose of this study was to measure the cross-sectional area and circumference of symptomatic and asymptomatic greater occipital nerves in patients with unilateral occipital neuralgia and to correlate the greater occipital nerve cross-sectional area with headache severity, sex, and body mass index.

METHODS

Both symptomatic and contralateral asymptomatic greater occipital nerve cross-sectional areas and circumferences were measured by a single examiner using sonography in 17 patients. The Wilcoxon signed rank test and Spearman rank order correlation coefficient were used to analyze the data.

RESULTS

Significant differences between the cross-sectional areas and circumferences of the symptomatic and asymptomatic greater occipital nerves were noted (P < .001). No difference existed in cross-sectional area (P = .40) or circumference (P = .10) measurements of the nerves between male and female patients. A significant correlation existed between the body mass index and symptomatic (r = 0.424; P = .045) and asymptomatic (r = 0.443; P = .037) cross-sectional areas. There was no correlation shown between the cross-sectional area of the symptomatic nerve and the severity of Headache Impact Test 6 scores (r = -0.342; P = .179).

CONCLUSIONS

We report sonographic evidence showing an increased cross-sectional area and circumference of the symptomatic greater occipital nerve in patients with unilateral occipital neuralgia.

Ultrasonic doppler flowmeter-guided occipital nerve block

BACKGROUND

Greater occipital nerve block is used in the treatment of headaches and neuralgia in the occipital area. We evaluated the efficacy of ultrasonic doppler flowmeter-guided occipital nerve block in patients experiencing headache in the occipital region in a randomized, prospective, placebo-controlled study.

METHODS

Twenty-six patients, aged 18 to 70, with headache in the occipital region, were included in the study. Patients received a greater occipital nerve block performed either under ultrasonic doppler flowmeter guidance using 1% lidocaine or the traditional method. Sensory examination findings in the occipital region were evaluated.

RESULTS

The complete block rate of greater occipital nerve blockade in the doppler group was significantly higher than in the control group respectively (76.9% vs. 30.8%, P < 0.05). Only one patient in the control group had a complication (minimal bleeding).

CONCLUSIONS

Ultrasonic doppler flowmeter-guided occipital nerve block may be a useful method for patients suffering headache in the occipital region.

The osmolyte trimethylamine N-oxide (TMAO) increases the proteolytic activity of botulinum neurotoxin light chains A, B, and E: implications for enhancing analytical assay sensitivity

Botulism, the disease caused by botulinum neurotoxins (BoNTs), secreted by the spore-forming, anaerobic bacteria Clostridium botulinum, has been associated with food poisoning for centuries. In addition, the potency of BoNTs coupled with the current political climate has produced a threat of intentional, malicious poisoning by these toxins. The ability to detect and measure BoNTs in complex matrixes is among the highest research priorities. However, the extreme potency of these toxins necessitates that assays be capable of detecting miniscule quantities of these proteins. Thus, signal-boosting strategies must be employed. A popular approach uses the proteolytic activity of the BoNT light chain (LC) to catalyze the cleavage of synthetic substrates; reaction products are then analyzed by the analytical platform of choice. However, BoNT LCs are poor catalysts. In this study, the authors used the osmolyte trimethylamine N-oxide (TMAO) to increase the proteolytic activities of BoNT LCs. Their data suggest that concentrated solutions of TMAO induce complete folding of the LCs, resulting in increased substrate affinity and enhanced enzyme turnover. The authors observed increases in catalysis for BoNT serotypes A, B, and E, and this increased proteolytic activity translated into substantial increases in analytical assay sensitivity for these medically relevant toxins.

Development of cell-based assays to measure botulinum neurotoxin serotype A activity using cleavage-sensitive antibodies

Botulinum neurotoxins (BoNTs) are zinc-metalloproteases that cleave components of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein complex, inhibiting acetylcholine release into neuromuscular junctions, resulting in flaccid paralysis and eventual death. The potential for the malicious misuse of these toxins as bioweapons has created an urgent need to develop effective therapeutic countermeasures. Robust cell-based assays will be essential for lead identification and the optimization of therapeutic candidates. In this study, the authors developed novel BoNT serotype A (BoNT/A) cleavage-sensitive (BACS) antibodies that only interact with full-length SNAP-25 (synaptosomal-associated protein of 25 kDa), the molecular target of the BoNT/A serotype. These antibodies exhibit high specificity for full-length SNAP-25, allowing the BoNT/A-mediated proteolysis of this protein to be measured in diverse assay formats, including several variations of enzyme-linked immunosorbent assay and multiple immunofluorescence methods. Assays built around the BACS antibodies displayed excellent sensitivity, had excellent reproducibility, and were amenable to multiwell formats. Importantly, these assays provided novel methods for evaluating BoNT/A activity in cellular models of intoxication and allowed for the high-throughput evaluation of experimental compounds.

Occipital nerve blocks: when and what to inject?

INTRODUCTION

Occipital nerve block (ONB) is a promising treatment for headaches. Its indications, selection criteria, and best techniques are not clear, however.

OBJECTIVE

To summarize in narrative format what is known about ONBs and what needs to be learned.

METHODS

MD Consult and Google Scholar were searched using the terms occipital, suboccipital, block, and injection to identify relevant articles that were reviewed. This process was repeated for all additional pertinent articles identified from these articles, and so on, until no additional articles were identified.

RESULTS

A total of 21 articles were identified.

CONCLUSIONS

Occipital nerve block is an effective treatment for cervicogenic headache, cluster headache, and occipital neuralgia. While a double blinded randomized placebo controlled clinical trial is lacking, multiple open label studies reported favorable results for migraine. Two other possible uses of ONB worthy of further study are use as a rescue treatment and as an adjunctive treatment for medication overuse headache. ONB may be effective for tension headache, but only under very specific circumstances. ONB is either ineffective or only effective under as yet unstudied circumstances for hemicrania continua and chronic paroxysmal hemicrania. Some practitioners use occipital nerve (ON) tenderness to palpation (TTP) or reproduction of headache pain with ON pressure (RHPONP) as selection criteria for identifying appropriate patients. While only a clinical trial can produce a definitive answer, current evidence suggests that these selection criteria are not necessary for cervicogenic headache or cluster headache. Occipital neuralgia by definition involves TTP of the ONs. Whether RHPONP or ON TTP predicts success in migraine is unclear, and may relate to whether steroids are used. A single blinded randomized controlled trial evaluating local anesthetic with steroids vs local anesthetic alone for transformed migraine reported slightly worse results with steroids, but there are several alternate explanations for this finding other than steroids being counterproductive. The technique of repetitive ONBs deserves further study.

The role of nerve blocks and botulinum toxin injections in the management of cluster headaches

Cluster headache (CH) is a primary headache syndrome that is classified with the trigeminal autonomic cephalalgias. CH treatment involves three steps: acute attack management, transitional therapy, and preventive therapy. Greater occipital nerve block has been shown to be an effective alternative bridge therapy to oral steroids in CH. Botulinum toxin type A has recently been studied as a new preventive treatment for patients with chronic CH, with limited success.