A good preoperative response to transcutaneous electrical nerve stimulation predicts a better therapeutic effect of implanted occipital nerve stimulation in pharmacologically intractable headaches

Transcutaneous electrical nerve stimulation of the occipital nerves as treatment for chronic cluster headache

BACKGROUND

Chronic cluster headache (CCH) is an excruciatingly painful condition that can be difficult to treat sufficiently with the available medical treatment options. The greater occipital nerves (GON) are of major interest in treating CCH, and various invasive treatment modalities, such as stimulating or blocking the nerves, have been applied. Because the terminal segment of the GON has a superficial course, the nerve is also accessible for non-invasive transcutaneous stimulation. Transcutaneous electrical nerve stimulation (TENS) has been suggested as a treatment for different chronic headaches, but evidence of the efficacy in patients with CCH is scarce. Additionally, no consensus exists on the optimal placement of the transcutaneous stimulation electrodes or the treatment usage pattern.

METHODS

In this explorative open-label clinical study, 36 patients with CCH were treated with TENS of the GON for 8-12 consecutive weeks between August 2021 and October 2023 as a separate part of the study protocol for a trial on stimulation of the GON (Clinicaltrials.gov identifier: NCT05023460). After a baseline period, TENS was used primarily as a preventive treatment, stimulating for 30 min twice daily at a minimum. The primary outcome was a change in attack frequency and safety with TENS treatment. Secondary outcomes were change in attack duration and pain intensity on the numeric rating scale, abortive treatments, and the Patient Global Impression of Change (PGIC) with TENS treatment. The change in attack frequency, duration, pain intensity, and use of abortive treatment was analyzed by comparing the baseline data with 4-weekly data from TENS treatment. The study aimed to systematically investigate the effect of TENS of the GON as a preventive treatment for CCH.

RESULTS

Weekly attack frequency decreased from a median of 15.7 (95% confidence interval [CI] 11.2-22.1) at baseline to 11.0 (95% CI 7.4-16.4) with TENS. In all, 13 of the 36 (36%) patients had a minimum 30% reduction in attack frequency. In the group of 30% responders, the number of weekly attacks decreased from 15.8 (95% CI 9.8-24.5) at baseline to 5.8 (95% CI 3.3-10.5) attacks with TENS. Five patients became entirely or nearly attack-free. For the entire cohort, attack duration and pain intensity were also significantly reduced with TENS. The use of oxygen was reduced by 42%, and triptan injections decreased by 55%. Overall, 15 (42%) patients reported a clinically important improvement with TENS treatment, rated on the PGIC scale. The 100 Hz stimulation programs were preferred over 10 Hz. No serious adverse events were registered.

CONCLUSION

Transcutaneous electrical nerve stimulation of the GON significantly reduced the frequency, intensity, and duration of weekly headache attacks in patients with severe CCH. Not all patients benefitted from TENS, but the treatment responders had a substantial improvement in their cluster headache. TENS treatment was well-tolerated with little or no side effects and could be a relevant supplement to conventional preventive treatment. A standard TENS apparatus is low cost, making the treatment accessible to most patients. This paper includes a detailed, comprehensive description of our clinical application of the therapy.

Conservative Management of Occipital Neuralgia Supported by Physical Therapy: A Review of Available Research and Mechanistic Rationale to Guide Treatment

PURPOSE OF REVIEW

Conservative management is consistently recommended as a first line intervention for occipital neuralgia (ON); however, there is limited clinical research regarding conservative intervention for ON. This lack of research may lead to underutilization or unwarranted variability in conservative treatment. This article provides mechanism-based guidance for conservative management of ON as a component of a multimodal treatment approach, and discusses the role of the physical therapist in the care team. It also highlights opportunities for further research to refine conservative management of this condition.

RECENT FINDINGS

Published research on conservative interventions specific to ON is limited to very low-quality evidence for the use of TENS. The contemporary shift toward precision pain management emphasizing treatment based on a patient's constellation of clinical features-a phenotype-rather than solely a diagnosis provides more personalized and specifically targeted pain treatment. This paradigm can guide treatment in cases where diagnosis-specific research is lacking and can be used to inform conservative treatment in this case. Various conservative interventions have demonstrated efficacy in treating many of the symptoms and accepted etiologies of ON. Conservative interventions provided by a physical therapist including exercise, manual therapy, posture and biomechanical training, TENS, patient education, and desensitization have mechanistic justification to treat symptoms and causes of ON. Physical therapists have adequate time and skill to provide such progressive and iterative interventions and should be included in a multimodal treatment plan for ON. Further research is required to determine appropriate dosing, sequencing, and progression of conservative treatments.

A surgical decision aid for occipital neuralgia with literature review and single center case series

BACKGROUND

Occipital neuralgia (ON) is a debilitating headache disorder. Due to the rarity of this disorder and lack of high-level evidence, a clear framework for choosing the optimal surgical approach for medically refractory ON incorporating shared decision making with patients does not exist.

METHODS

A literature review of studies reporting pain outcomes of patients who underwent surgical treatment for ON was performed, as well as a retrospective chart review of patients who underwent surgery for ON within our institution.

RESULTS

Thirty-two articles met the inclusion criteria. A majority of the articles were retrospective case series (22/32). The mean number of patients across the studies was 34 (standard deviation (SD) 39). Among the 13 studies that reported change in pain score on 10-point scales, a study of 20 patients who had undergone C2 and/or C3 ganglionectomies reported the greatest reduction in pain intensity after surgery. The studies evaluating percutaneous ablative methods including radiofrequency ablation and cryoablation showed the smallest reduction in pain scores overall. At our institution from 2014 to 2023, 11 patients received surgical treatment for ON with a mean follow-up of 187 days (SD 426).

CONCLUSION

Based on these results, the first decision aid for selecting a surgical approach to medically refractory ON is presented. The algorithm prioritizes nerve sparing followed by non-nerve sparing techniques with the incorporation of patient preference. Shared decision making is critical in the treatment of ON given the lack of clear scientific evidence regarding the superiority of a particular surgical method.

The Untold Story of Occipital Nerve Stimulation in Patients With Cluster Headache: Surgical Technique in Relation to Clinical Efficacy

OBJECTIVES

Approximately one in every 1000 adults experiences cluster headache (CH). Although occipital nerve stimulation (ONS) appears encouraging in treatment for most patients with refractory CH, some patients do not reach adequate pain relief with ONS. A reason for failure of ONS might be anatomical variations and different surgical approaches. Therefore, an extensive literature analysis was performed, and cadaveric experimentation was combined with our clinical experience to provide a standardized proposal for ONS and obtain optimal management of patients with refractory CH.

MATERIALS AND METHODS

Data from 36 articles published between 1998 and 2023 were analyzed to retrieve information on the anatomical landmarks and surgical technique of ONS. For the cadaveric experimentation (N = 1), two electrodes were inserted from the region over the foramen magnum and projected toward the lower third of the mastoid process.

RESULTS

The existence of multiple approaches of ONS has been confirmed by the present analysis. Discrepancies have been found in the anatomical locations and corresponding landmarks of the greater and lesser occipital nerve. The surgical approaches differed in patient positioning, electrode placement, and imaging techniques, with an overall efficacy range of 35.7% to 90%.

CONCLUSIONS

Reports on the surgical approach of ONS remain contradictory, hence emphasizing the need for standardization. Only if all implanting physicians perform the ONS surgery using a standardized protocol, can future data be combined and outcomes compared and analyzed.

Treatment of cognitive and mood disorders secondary to traumatic brain injury by the association of bilateral occipital nerve stimulation and a combined protocol of multisite repetitive transcranial magnetic stimulation and cognitive training: A case report

Purpose

Cognitive impairment secondary to traumatic brain injury (TBI) is difficult to treat and usually results in severe disability.

Method

A 48-year-old man presented with chronic refractory headaches and persistent disabling cognitive impairment after TBI. He was first treated with occipital nerve stimulation (ONS) implanted bilaterally to relieve headaches (8 years after the head trauma). Two years later, he was treated with a 6-week protocol combining repetitive transcranial magnetic stimulation (rTMS) delivered to multiple cortical sites (prefrontal cortex, language areas, and areas involved in visuo-spatial functions) and computerized cognitive training (CogT) (targeting memory, language, and visuo-spatial functions) to improve cognitive performance.

Results

Executive and cognitive functions (attention, ability to perform calculations, and verbal fluency) improved in association with pain relief after ONS (33-42% improvement) and then improved even more after the rTMS-CogT protocol with an additional improvement of 36-40% on apathy, depression, and anxiety, leading to a significant reduction in caregiver burden. The functional improvement persisted and even increased at 6 months after the end of the rTMS-CogT procedure (10 years after the onset of TBI and 2 years after ONS implantation).

Conclusion

This is the first observation describing sustained improvement in post-TBI refractory headache, depression, and cognitive impairment by the association of bilaterally implanted ONS and a combined procedure of multisite rTMS and CogT to target various brain functions.

The HortONS study. Treatment of chronic cluster headache with transcutaneous electrical nerve stimulation and occipital nerve stimulation: study protocol for a prospective, investigator-initiated, double-blinded, randomized, placebo-controlled trial

BACKGROUND

Chronic cluster headache (CCH) is a debilitating primary headache disorder. Occipital nerve stimulation (ONS) has shown the potential to reduce attack frequency, but the occipital paresthesia evoked by conventional (tonic) stimulation challenges a blinded comparison of active stimulation and placebo. Burst ONS offers paresthesia-free stimulation, enabling a blinded, placebo-controlled study. Identification of a feasible preoperative test would help select the best candidates for implantation. This study aims to explore ONS as a preventive treatment for CCH, comparing burst stimulation to tonic stimulation and placebo, and possibly identifying a potential preoperative predictor.

METHODS

An investigator-initiated, double-blinded, randomized, placebo-controlled trial is conducted, including 40 patients with CCH. Eligible patients complete a trial with the following elements: I) four weeks of baseline observation, II) 12 weeks of transcutaneous electrical nerve stimulation (TENS) of the occipital nerves, III) implantation of a full ONS system followed by 2 week grace period, IV) 12 weeks of blinded trial with 1:1 randomization to either placebo (deactivated ONS system) or burst (paresthesia-free) stimulation, and V) 12 weeks of tonic stimulation. The primary outcomes are the reduction in headache attack frequency with TENS and ONS and treatment safety. Secondary outcomes are treatment efficacy of burst versus tonic ONS, the feasibility of TENS as a predictor for ONS outcome, reduction in headache pain intensity (numeric rating scale), reduction in background headache, the patient's impression of change (PGIC), health-related quality of life (EuroQoL-5D), self-reported sleep quality, and symptoms of anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Data on headache attack characteristics are registered weekly. Data on patient-reported outcomes are assessed after each trial phase.

DISCUSSION

The study design allows a comparison between burst ONS and placebo in refractory CCH and enables a comparison of the efficacy of burst and tonic ONS. It will provide information about the effect of burst ONS and explore whether the addition of this stimulation paradigm may improve stimulation protocols. TENS is evaluated as a feasible preoperative screening tool for ONS outcomes by comparing the effect of attack prevention of TENS and tonic ONS.

TRIAL REGISTRATION

The study is registered at Clinicaltrials.gov (trial registration number NCT05023460, registration date 07-27-2023).

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.

Occipital Neuralgia

PURPOSE OF REVIEW

Occipital neuralgia is a painful condition that affects the posterior aspect of the head and can be difficult to distinguish from other common forms of headaches. This article reviews the anatomy, pathophysiology, clinical presentation, differential diagnosis, diagnostic testing, and management approaches for occipital neuralgia.

RECENT FINDINGS

Non-pharmacological treatments aim to alleviate muscle tension and improve posture. Acupuncture shows some promise. The occipital nerve block is considered the first line in a minimally invasive intervention, but the duration of relief may be short term. An onabotulinum toxin A injection may improve the sharp but not the dull component of the pain of occipital neuralgia. Radiofrequency ablation and occipital nerve stimulation may provide effective long-term relief in refractory patients. Surgical decompression, neurotomies, and neurolysis are last-resort treatment options. Occipital neuralgia is a debilitating condition that can be difficult to treat. Studies with larger sample sizes and randomized control trials are needed to further determine the effectiveness and safety of different therapies.

Neuromodulation techniques for acute and preventive migraine treatment: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Several neuromodulation methods exists for migraine treatment. The aim of the present study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) focusing on migraine treatment using neurostimulation methods.

METHODS

We searched Medline and Embase up to July 1, 2020 for RCTs reporting acute or preventive treatment of migraine with either non-invasive or invasive neurostimulation methods. Two researchers independently assessed the eligibility of the retrieved studies and extracted data. Outcomes for the quantitative synthesis were 2 h pain free for acute treatment and headache days per month for preventive treatment. We performed subgroup analyses by treatment (stimulation method and site of application). Estimates were pooled using random-effects meta-analysis.

RESULTS

Thirty-eight articles were included in the qualitative analysis (7 acute, 31 preventive) and 34 in the quantitative evaluation (6 acute, 28 preventive). Remote electrical neuromodulation (REN) was effective for acute treatment. Data were insufficient to draw conclusions for any other techniques (single studies). Invasive occipital nerve stimulation (ONS) was effective for migraine prevention, with a large effect size but considerable heterogeneity, whereas supra-orbital transcutaneous electrical nerve stimulation (TENS), percutaneous electrical nerve stimulation (PENS), and high-frequency repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) were effective, with small to medium effect sizes. Vagus-nerve stimulation, left prefrontal cortex rTMS, and cathodal transcranial direct current stimulation (tDCS) over the M1 had no significant effect and heterogeneity was high.

CONCLUSION

Several neuromodulation methods are of potential interest for migraine management, but the quality of the evidence is very poor. Future large and well-conducted studies are needed and could improve on the present results.

Neuromodulation in headache and craniofacial neuralgia: guidelines from the Spanish Society of Neurology and the Spanish Society of Neurosurgery

INTRODUCTION

Numerous invasive and non-invasive neuromodulation devices have been developed and applied to patients with headache and neuralgia in recent years. However, no updated review addresses their safety and efficacy, and no healthcare institution has issued specific recommendations on their use for these 2 conditions.

METHODS

Neurologists from the Spanish Society of Neurology's (SEN) Headache Study Group and neurosurgeons specialising in functional neurosurgery, selected by the Spanish Society of Neurosurgery (SENEC), performed a comprehensive review of articles on the MEDLINE database addressing the use of the technique in patients with headache and neuralgia.

RESULTS

We present an updated review and establish the first set of consensus recommendations of the SEN and SENC on the use of neuromodulation to treat headache and neuralgia, analysing the current levels of evidence on its effectiveness for each specific condition.

CONCLUSIONS

Current evidence supports the indication of neuromodulation techniques for patients with refractory headache and neuralgia (especially migraine, cluster headache, and trigeminal neuralgia) selected by neurologists and headache specialists, after pharmacological treatment options are exhausted. Furthermore, we recommend that invasive neuromodulation be debated by multidisciplinary committees, and that the procedure be performed by teams of neurosurgeons specialising in functional neurosurgery, with acceptable rates of morbidity and mortality.

Neurostimulation methods in the treatment of chronic pain

The goal of this narrative review was to give an up-to-date overview of the peripheral and central neurostimulation methods that can be used to treat chronic pain. Special focus has been given to three pain conditions: neuropathic pain, nociplastic pain and primary headaches. Both non-invasive and invasive techniques are briefly presented together with their pain relief potentials. For non-invasive stimulation techniques, data concerning transcutaneous electrical nerve stimulation (TENS), transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), remote electrical neuromodulation (REN) and vagus nerve stimulation (VNS) are provided. Concerning invasive stimulation techniques, occipital nerve stimulation (ONS), vagus nerve stimulation (VNS), epidural motor cortex stimulation (EMCS), spinal cord stimulation (SCS) and deep brain stimulation (DBS) are presented. The action mode of all these techniques is only partly understood but can be very different from one technique to the other. Patients' selection is still a challenge. Recent consensus-based guidelines for clinical practice are presented when available. The development of closed-loop devices could be of interest in the future, although the clinical benefit over open loop is not proven yet.

Systematic review of the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion for the treatment of refractory chronic cluster headache

INTRODUCTION

This study aimed to assess the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion (SPG) in the treatment of refractory chronic cluster headache.

DEVELOPMENT

Various medical databases were used to perform a systematic review of the scientific literature. The search for articles continued until 31 October 2016, and included clinical trials, systematic reviews and/or meta-analyses, health technology assessment reports, and clinical practice guidelines that included measurements of efficiency/effectiveness or adverse effects associated with the treatment. The review excluded cohort studies, case-control studies, case series, literature reviews, letters to the editor, opinion pieces, editorials, and studies that had been duplicated or outdated by later publications from the same institution. Regarding effectiveness, we found that SPG stimulation had positive results for pain relief, attack frequency, medication use, and patients' quality of life. In the results regarding safety, we found a significant number of adverse events in the first 30 days following the intervention. Removal of the device was necessary in some patients. Little follow-up data, and no long-term data, is available.

CONCLUSIONS

These results are promising, despite the limited evidence available. We consider it essential for research to continue into the safety and efficacy of SPG stimulation for patients with refractory chronic cluster headache. In cases where this intervention may be indicated, treatment should be closely monitored.

Occipital Neuralgia and Cervicogenic Headache: Diagnosis and Management

PURPOSE OF REVIEW

Occipital neuralgia (ON) and cervicogenic headache (CGH) are secondary headache disorders with occipital pain as a key feature. Due to significant phenotypic overlap, differentiating ON and CGH from primary headache disorders such as migraine or tension-type headache, or other secondary headache disorders, can be clinically challenging. This article reviews the anatomy, clinical features, unique diagnostic considerations, and management approaches relating to ON and CGH.

RECENT FINDINGS

Conservative therapeutic approaches are considered first-line. Anesthetic nerve blocks may have a dual role in both supporting diagnosis and providing pain relief. Newer minimally invasive procedures, such as pulsed radiofrequency (PRF) and occipital nerve stimulation (ONS), represent an exciting therapeutic avenue for severe/refractory cases. Surgical interventions should be reserved for select patient populations who have failed all other conservative and minimally invasive options, to be weighed against potential risk. ON and CGH represent an ongoing diagnostic challenge. Further studies are required to consolidate efficacy regarding the comprehensive management of ON and CGH.

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.

Systematic review of the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion for the treatment of refractory chronic cluster headache

INTRODUCTION

This study aimed to assess the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion (SPG) in the treatment of refractory chronic cluster headache.

DEVELOPMENT

Various medical databases were used to perform a systematic review of the scientific literature. The search for articles continued until 31 October 2016, and included clinical trials, systematic reviews and/or meta-analyses, health technology assessment reports, and clinical practice guidelines that included measurements of efficiency/effectiveness or adverse effects associated with the treatment. The review excluded cohort studies, case-control studies, case series, literature reviews, letters to the editor, opinion pieces, editorials, and studies that had been duplicated or outdated by later publications from the same institution. Regarding effectiveness, we found that SPG stimulation had positive results for pain relief, attack frequency, medication use, and patients' quality of life. In the results regarding safety, we found a significant number of adverse events in the first 30 days following the intervention. Removal of the device was necessary in some patients. Little follow-up data, and no long-term data, is available.

CONCLUSIONS

These results are promising, despite the limited evidence available. We consider it essential for research to continue into the safety and efficacy of SPG stimulation for patients with refractory chronic cluster headache. In cases where this intervention may be indicated, treatment should be closely monitored.

Predictors of response to occipital nerve stimulation in refractory chronic headache

Background

Occipital nerve stimulation is a promising treatment for refractory chronic headache disorders, but is invasive and costly. Identifying predictors of response would be useful in selecting patients. We present the results of an open-label prospective cohort study of 100 patients (35 chronic migraine, 33 chronic cluster headache, 20 short-lasting unilateral neuralgiform headache attacks and 12 hemicrania continua) undergoing occipital nerve stimulation, using a multivariate binary regression analysis to identify predictors of response.

Results

Response rate of the cohort was 48%. Multivariate analysis showed short lasting unilateral neuralgiform headache attacks (OR 6.71; 95% CI 1.49–30.05; p = 0.013) and prior response to greater occipital nerve block (OR 4.22; 95% CI 1.35–13.21; p = 0.013) were associated with increased likelihood of response. Presence of occipital pain (OR 0.27; 95% CI 0.09–0.76; p = 0.014) and the presence of severe anxiety and/or depression (as measured on hospital anxiety and depression score) at time of implantation (OR 0.32; 95% CI 0.11–0.91; p = 0.032) were associated with reduced likelihood of response.

Conclusion

Possible clinical predictors of response to occipital nerve stimulation for refractory chronic headaches have been identified. Our data shows that those with short-lasting unilateral neuralgiform headache attacks respond better than those with chronic migraine, and that a prior response to greater occipital nerve block is associated with positive outcomes. This study suggests that the presence of occipital pain and severe mood disorder at time of implant are both associated with poor outcomes to occipital nerve stimulation.