Long-Term Pain Reduction Does Not Imply Improved Functional Outcome in Patients Treated With Combined Supraorbital and Occipital Nerve Stimulation for Chronic Migraine

Breaking the cycle: unraveling the diagnostic, pathophysiological and treatment challenges of refractory migraine

Background

Refractory migraine is a poorly described complication of migraine in which migraine has chronified and become resistant to standard treatments. The true prevalence is unknown, but medication resistance is common in headache clinic patient populations. Given the lack of response to treatment, this patient population is extremely difficult to treat with limited guidance in the literature.

Objective

To review the diagnostic, pathophysiological, and management challenges in the refractory migraine population.

Discussion

There are no accepted, or even ICHD-3 appendix, diagnostic criteria for refractory migraine though several proposed criteria exist. Current proposed criteria often have low bars for refractoriness while also not meeting the needs of pediatrics, lower socioeconomic status, and developing nations. Pathophysiology is unknown but can be hypothesized as a persistent "on" state as a progression from chronic migraine with increasing central sensitization, but there may be heterogeneity in the underlying pathophysiology. No guidelines exist for treatment of refractory migraine; once all guideline-based treatments are tried, treatment consists of n-of-1 treatment trials paired with non-pharmacologic management.

Conclusion

Refractory migraine is poorly described diagnostically, its pathophysiology can only be guessed at by extension of chronic migraine, and treatment is more the art than science of medicine. Navigating care of this refractory population will require multidisciplinary care models and an emphasis on future research to answer these unknowns.

Update of Neuromodulation in Chronic Migraine

Purpose of Review

Neuromodulation devices have become an attractive alternative to traditional pharmacotherapy for migraine, especially for patients intolerant to medication or who prefer non-pharmacological options. In the past decades, many studies demonstrated the efficacy of neuromodulation devices in patients with episodic migraine (EM). However, the benefit of these devices on chronic migraine (CM), which is typically more debilitating and refractory than EM, remains not well studied.

Recent Findings

We reviewed the literature within the last five years on using FDA-cleared and investigational devices for CM. There were eight randomized controlled trials and 15 open-label observational studies on ten neuromodulation devices.

Summary

Neuromodulation is promising for use in CM, although efficacy varies among devices or individuals. Noninvasive devices are usually considered safe with minimal adverse events. However, stimulation protocol and methodology differ between studies. More well-designed studies adhering to the guideline may facilitate FDA clearance and better insurance coverage.

An unusual case of lead migration in occipital nerve stimulation: A case report and literature review

Background:

Lead migration is a complication associated with occipital nerve stimulation (ONS). We present a rare case in which fibrosis in the stress relief loop caused lead migration in the treatment of occipital neuralgia.

Case Description:

A 30-year-old woman with a 5-year history of refractory occipital neuralgia, who had been under ONS therapy for 2 months, presented with a sudden onset of typical occipital neuralgia pain associated with cervical muscles spasms and myoclonus. A skull radiography showed lead migration. The patient underwent surgery for lead repositioning. During surgery, we identified extensive fibrosis throughout the stress relief loop that produced several constriction points. The fibrosis in the stress relief loop increased tension on the lead during head-and-neck movement, causing progressive migration of the lead.

Conclusion:

Although lead migration is a common complication of ONS, its association with fibrosis in the stress relief loop has not, to the best of our knowledge, been reported before. Lead migration can directly affect treatment outcome and it is, therefore, important to fully understand the possible mechanisms that can cause it and how to promptly manage them.

Long-Term Experience with Occipital and Supraorbital Nerve Stimulation for the Various Headache Disorders-A Retrospective Institutional Case Series of 96 Patients

OBJECTIVE

We have provided long-term data on clinically meaningful pain alleviation for drug-refractory headache disorders using occipital (ONS) and supraorbital nerve stimulation (SONS).

METHODS

We performed a retrospective review of 96 patients with migraine, cervicogenic headache, cluster headache, neuropathic pain of the scalp, tension-type headache, and new daily persistent headache who had undergone ONS (61.5%), SONS (11.5%), or combined ONS plus SONS (27.1%) trial implantation and definitive implantation from 2007 to 2017. Changes in pain perception over time were monitored using the visual analog scale (VAS) for pain.

RESULTS

The cohort consisted of 60.4% women and 39.6% men, with a mean age of 46.9 ± 11.5 years and pain duration of 14 ± 14.1 years. Of the 96 patients, 65 (67.7%) were treatment responders to a trial (≥30% amelioration in the average or maximum VAS score for pain and/or number of headache days) that had lasted 22.5 ± 8.8 days. The reduction in their average VAS score for pain was to 37% ± 24.4% of baseline compared with 99.1% ± 24.1% of baseline for those without a response (P < 0.01). Of the 56 patients who had undergone implantation and had long-term follow-up data available for ≤10 years, 32 (57.1%) reported a ≥50% reduction in their average VAS score for pain. Four patients (6.5%) had requested hardware explantation. Stage II complications included 1 infection (1.6%) and 6 electrode dislocations (9.7%). The study limitations included the retrospective nature, lack of controls receiving placebo intervention, and randomization.

CONCLUSIONS

After careful patient selection according to a positive response to a trial of ONS and/or SONS, clinically meaningful long-term benefit was achieved in 57.1% of our patients with various chronic headache conditions.

Outcomes of Occipital Nerve Stimulation for Craniofacial Pain Syndromes

OBJECTIVES

Occipital nerve regional stimulation (ONS) is reported to improve pain in several studies. We examined long-term pain and functional outcomes of ONS in an open-label prospective study.

METHODS

Patients with medically refractory and disabling craniofacial pain were prospectively selected for ONS. Primary outcome was a change in mean daily pain intensity on the numeric pain rating scale (NPRS) at 6 months. Secondary outcomes included changes in NPRS, Headache Impact Test-6 (HIT-6), Migraine Disability Assessment (MIDAS), Pain Disability Index (PDI), Center for Epidemiologic Studies Depression Scale - Revised (CESD-R), and Short Form-36 version 2 (SF36) at last follow-up.

RESULTS

Thirteen patients (mean age 49.7 ± 8.4) diagnosed with occipital neuralgia (6), hemicrania continua (2), persistent idiopathic facial pain (2), post-traumatic facial pain (1), cluster headache (1), and chronic migraine (1) were enrolled. Mean NPRS improved by 2.1 ± 2.1 at 6 months and 2.1 ± 1.9 at last follow-up (23.5 ± 18.1 months). HIT-6 decreased by 8.7 ± 8.8, MIDAS decreased by 61.3 ± 71.6, and PDI decreased by 17.9 ± 18. SF36 physical functioning, bodily pain, and social functioning improved by 16.4 ± 19.6, 18.0 ± 31.6, and 26.1 ± 37.3, respectively. Moderate to severe headache days (defined as ≥50% of baseline mean NPRS) were reduced by 8.9 ± 10.2 days per month with ONS.

CONCLUSION

ONS reduced the long-term NPRS and moderate-severe monthly headache days by 30% and improved functional outcomes and quality of life. A prospective registry for ONS would be helpful in accumulating a larger cohort with longer follow-up in order to improve the use of ONS.

Occipital Nerve Stimulation in Chronic Migraine: The Relationship Between Perceived Sensory Quality, Perceived Sensory Location, and Clinical Efficacy-A Prospective, Observational, Non-Interventional Study

Introduction

Occipital nerve stimulation (ONS) is used to treat therapy-resistant chronic migraine. Clinical use has resulted in a wide intraindividual and interindividual variation of clinical efficacy. The aim of this study was to analyze a potential relationship between sociodemographic variables, headache parameters, perceived sensory quality, perceived sensory location, as well as clinical efficacy.

Methods

Thirty-two subjects (21.9% male, mean age 45.77 years) suffering from chronic migraine refractory to other treatment and therefore treated with ONS were included in this study. We used a computer-based imaging method for mapping the ONS-induced perceived sensory location, the perceived spatial sensory field size, as well as the perceived sensory quality in a long-term course over 21 months in weekly time intervals. Additionally, the effect of ONS on the migraine headache was documented weekly by the participants using a verbal rating scale. Over the observation period, a total of 808 individual weekly data sets were recorded and a potential relationship between ONS-induced perceptions and headache parameters could be analyzed.

Results

We found that 48.9% of stimulation intervals were reported as effective by patients. Women displayed a significantly higher responder rate than men. The reported effectiveness did not differ depending on age, the average number of migraine days per month, the MIDAS score, or the duration of the migraine disorder prior to ONS treatment. Implantation with trial period led to significantly lower responder rates than without the trial period. The most frequently perceived sensory quality of “tingling” was found significantly more frequently in non-responders than in responders. Responders displayed significantly lower pleasantness scores for their reported perceptions than non-responders. Sensations that were spatially perceived above the line connecting the external acoustic meati with the external occipital protuberance (MOP line) led to patients reporting a positive clinical effect significantly more frequently than sensations spatially perceived below the MOP line. Spatially small fields of sensory perception were correlated with a higher responder rate than those covering broader areas.

Conclusions

The ONS-induced sensory location, the size of the spatial sensory field, as well as the sensory quality are significantly correlated with the reported clinical effectiveness. The results suggest that besides surgical technique, the individual and continuous programming of the stimulation parameters is clinically relevant in increasing the therapeutic effectiveness.

Craniofacial Peripheral Nerve Stimulation: Analysis of a Single Institution Series

OBJECTIVE

Objective real-world experience with peripheral nerve stimulation (PNS) is limited. Furthermore, the lack of robust outcome metrics, long-term follow-up and data comparing responders and nonresponders limit the refinement of selection criteria to better identify patients likely to benefit from PNS.

MATERIALS AND METHODS

We retrospectively analyzed 22 patients with craniofacial pain treated with PNS, and responders were classified as having ≥50% postoperative improvement in the numeric rating scale (NRS). In a subset of patients (n = 11), detailed prospective outcomes metrics were obtained preoperatively and postoperatively, including NRS, Beck Depression Index (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ).

RESULTS

About 59.1% (13 of 22) of subjects were classified as responders at a mean follow-up of 37.5 ± 5.27 months. Diagnoses included migraine (n = 6), occipital neuralgia (n = 9), trigeminal neuropathic pain (TNP; n = 6), and central poststroke pain (n = 1). Within the TNP subgroup, responders were more likely to have undergone two or more trigeminal neuralgia procedures prior to PNS (p < 0.05). In the 11 patients with comprehensive preoperative and postoperative outcome data, we noted significant improvement in NRS (p = 0.0005), BDI (p = 0.04), PCS (p = 0.01), as well as components of PCS (helplessness and magnification, p = 0.02) and MPQ (affective, p = 0.02).

CONCLUSIONS

The present study adds to the PNS literature by providing long-term data and multiple outcome metrics in a subset of patients. We suggest that BDI, PCS, and MPQ may provide more insight into meaningful response over time. Evaluating functional and quality of life outcomes in patients with craniofacial pain may be more informative than assessing benefit solely based on pain intensity and responder rates.

Supraorbital Occipital Circumferential Stimulation for the Treatment of Refractory Chronic Primary Headache: A Case Series

BACKGROUND

Patients with refractory chronic primary headache disorders have extremely debilitating symptoms, severe comorbidities (e.g., anxiety, depression), and a significant reduction in quality of life. The headaches are extremely difficult to treat, as they are often refractory to pharmacologic and procedural interventions. Neuromodulation with stimulation of the occipital and supraorbital nerves has been proposed as a viable treatment for these refractory headaches. We retrospectively review the long-term (33.5 ± 20 months) results of supraorbital occipital nerve circumferential stimulation (SOCS) in patients with chronic primary headache disorders.

METHODS

We retrospectively review 25 patients who were evaluated for SOCS for chronic primary headache disorders from 2010 to 2017 at a single institution with a single neurosurgeon.

RESULTS

Of these 25 patients, 14 saw benefits to their trial stage of stimulation and underwent full implantation. A total 3 patients were excluded from further analysis because of having <2 months of follow-up or discordant data. Of the 11 patients analyzed, there was an overall response rate (≥50% pain reduction) of 82%. The average preoperative 10-point pain score dropped from 7.1 ± 1.6 to a postoperative score of 3.3 ± 2.1. However, there was a high rate of complications including infection, erosion, and loss of effect.

CONCLUSIONS

The results (82% response) suggest that SOCS may be an effective treatment and should be studied more extensively. Occipital nerve stimulation alone has shown 40% to 50% response rate in published studies. However, the relatively high complication rate highlights an obstacle for the approach for the treatment of refractory headache disorders and room for device optimization.

Neurostimulation for the treatment of chronic migraine and cluster headache

Small subsets of patients who fail to respond to pharmacological treatment may benefit from alternative treatment methods. In the last decade, neurostimulation is being explored as a potential treatment option for the patients with chronic, severely disabling refractory primary headaches. To alleviate pain, specific nerves and brain areas have been stimulated, and various methods have been explored: deep brain stimulation, occipital nerve stimulation, and sphenopalatine ganglion stimulation are among the more invasive ones, whereas transcranial magnetic stimulation and supraorbital nerve stimulation are noninvasive. Vagal nerve stimulation can be invasive or noninvasive, though this review included only data for noninvasive VNS. Most of these methods have been tested in small open-label patient series; recently, more data from randomized, controlled, and blinded studies are available. Although neurostimulation treatments have demonstrated good efficacy in many studies, it still has not been established as a standard treatment in refractory patients. This review analyzes the available evidence regarding efficacy and safety of different neurostimulation modalities for the treatment of chronic migraine and cluster headache.

External Trigeminal Nerve Stimulation for the Acute Treatment of Migraine: Open-Label Trial on Safety and Efficacy

OBJECTIVE

The aim of the current study is to assess the safety and efficacy of external trigeminal nerve stimulation (e-TNS) via a transcutaneous supraorbital stimulator as an acute treatment for migraine attacks.

MATERIALS AND METHODS

This was a prospective, open-labeled clinical trial conducted at the Columbia University Headache Center (NY, USA). Thirty patients who were experiencing an acute migraine attack with or without aura were treated with a one-hour session of e-TNS (CEFALY Technology) at the clinic. Pain intensity was scored using a visual analogue scale (VAS) before the treatment, after the one-hour treatment session, and at two hours after treatment initiation. Rescue migraine medication intake was recorded at 2 and 24 hours.

RESULTS

Thirty patients were included in the intention-to-treat analysis. Mean pain intensity was significantly reduced by 57.1% after the one-hour e-TNS treatment (-3.22 ± 2.40; p < 0.001) and by 52.8% at two hours (-2.98 ± 2.31; p < 0.001). No patients took rescue medication within the two-hour observation phase. Within the 24-hour follow-up, 34.6% of patients used a rescue medication. No adverse events or subjective complaints were reported.

CONCLUSIONS

The findings from this open-labeled study suggest that transcutaneous supraorbital neurostimulation may be a safe and effective acute treatment for migraine attacks, and merits further study with a double-blind, randomized, sham-controlled trial.

Current and novel insights into the neurophysiology of migraine and its implications for therapeutics

Migraine headache and its associated symptoms have plagued humans for two millennia. It is manifest throughout the world, and affects more than 1/6 of the global population. It is the most common brain disorder, and is characterized by moderate to severe unilateral headache that is accompanied by vomiting, nausea, photophobia, phonophobia, and other hypersensitive symptoms of the senses. While there is still a clear lack of understanding of its neurophysiology, it is beginning to be understood, and it seems to suggest migraine is a disorder of brain sensory processing, characterized by a generalized neuronal hyperexcitability. The complex symptomatology of migraine indicates that multiple neuronal systems are involved, including brainstem and diencephalic systems, which function abnormally, resulting in premonitory symptoms, ultimately evolving to affect the dural trigeminovascular system, and the pain phase of migraine. The migraineur also seems to be particularly sensitive to fluctuations in homeostasis, such as sleep, feeding and stress, reflecting the abnormality of functioning in these brainstem and diencephalic systems. Implications for therapeutic development have grown out of our understanding of migraine neurophysiology, leading to major drug classes, such as triptans, calcitonin gene-related peptide receptor antagonists, and 5-HT1F receptor agonists, as well as neuromodulatory approaches, with the promise of more to come. The present review will discuss the current understanding of the neurophysiology of migraine, particularly migraine headache, and novel insights into the complex neural networks responsible for associated neurological symptoms, and how interaction of these networks with migraine pain pathways has implications for the development of novel therapeutics.

Invasive and Non-invasive Electrical Pericranial Nerve Stimulation for the Treatment of Chronic Primary Headaches

Chronic primary headaches are widespread disorders which cause significant quality of life and socioprofessional impairment. Available pharmacological treatments have often a limited efficacy and/or can generate unbearable side effects. Electrical nerve stimulation is a well-known non-destructive method of pain modulation which has been recently applied to headache management. In this review, we summarise recent advances in invasive and non-invasive neurostimulation techniques targeting pericranial structures for the treatment of chronic primary headaches, chiefly migraine and cluster headache: occipital nerve, supraorbital nerve, vagus nerve, and sphenopalatine ganglion stimulations. Invasive neurostimulation therapies have offered a new hope to drug-refractory headache sufferers but are not riskless and should be proposed only to chronic patients who failed to respond to most existing preventives. Non-invasive neurostimulation devices are user-friendly, safe and well tolerated and are thus taking an increasing place in the multidisciplinary therapeutical armamentarium of primary headaches.

Long-term outcomes of occipital nerve stimulation for chronic migraine: a cohort of 53 patients

Background

Chronic migraine affects up to 2 % of the general population and has a substantial impact on sufferers. Occipital nerve stimulation has been investigated as a potentially effective treatment for refractory chronic migraine. Results from randomised controlled trials and open label studies have been inconclusive with little long-term data available.

Methods

The long-term efficacy, functional outcome and safety of occipital nerve stimulation was evaluated in an uncontrolled, open-label, prospective study of 53 intractable chronic migraine patients.

Results

Fifty-three patients were implanted in a single centre between 2007 and 2013. Patients had a mean age of 47.75 years (range 26–70), had suffered chronic migraine for around 12 years and had failed a mean of 9 (range 4–19) preventative treatments prior to implant. Eighteen patients had other chronic headache phenotypes in addition to chronic migraine. After a median follow-up of 42.00 months (range 6–97) monthly moderate-to-severe headache days (i.e. days on which pain was more than 4 on the verbal rating score and lasted at least 4 h) reduced by 8.51 days (p < 0.001) in the whole cohort, 5.80 days (p < 0.01) in those with chronic migraine alone and 12.16 days (p < 0.001) in those with multiple phenotypes including chronic migraine. Response rate of the whole group (defined as a >30 % reduction in monthly moderate-to-severe headache days) was observed in 45.3 % of the whole cohort, 34.3 % of those with chronic migraine alone and 66.7 % in those with multiple headache types. Mean subjective patient estimate of improvement was 31.7 %. Significant reductions were also seen in outcome measures such as pain intensity (1.34 points, p < 0.001), all monthly headache days (5.66 days, p < 0.001) and pain duration (4.54 h, p < 0.001). Responders showed substantial reductions in headache-related disability, affect scores and quality of life measures. Adverse event rates were favourable with no episodes of lead migration and only one minor infection reported.

Conclusions

Occipital nerve stimulation may be a safe and efficacious treatment for highly intractable chronic migraine patients even after relatively prolonged follow up of a median of over 3 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-016-0659-0) contains supplementary material, which is available to authorized users.