Defining Refractory Migraine and Refractory Chronic Migraine: Proposed Criteria From the Refractory Headache Special Interest Section of the American Headache Society

Updated Canadian Headache Society Migraine Prevention Guideline with Systematic Review and Meta-analysis

OBJECTIVE

We have updated the migraine prevention guideline of the Canadian Headache Society from 2012, as there are new therapies available, and additionally, we have provided guidelines for the prevention of chronic migraine, which was not addressed in the previous iteration.

METHODS

We undertook a systematic review to identify new studies since the last guideline. For studies identified, we performed data extraction and subsequent meta-analyses where possible. We composed a summary of the evidence found and undertook a modified Delphi recommendation process. We provide recommendations for treatments identified and additionally expert guidance on the use of the treatments available in important clinical situations.

RESULTS

We identified 61 studies that were included in this evidence update and identified 16 therapies we focused on. The anti-calcitonin gene-related peptide (CGRP) agents were approved by Health Canada between 2018 and 2024 and provide additional options for episodic and chronic migraine prevention. We also summarize evidence for the use of propranolol, topiramate and onabotulinumtoxinA in addition to anti-CGRP agents as treatments for chronic migraine. We have downgraded topiramate to a weak recommendation for use and gabapentin to a weak recommendation against its use in episodic migraine. We have weakly recommended the use of memantine, levetiracetam, enalapril and melatonin in episodic migraine.

CONCLUSION

Based on the evidence synthesis, we provide updated recommendations for the prevention of episodic and chronic migraine utilizing treatments available in Canada. We additionally provided expert guidance on their use in clinical situations.

Characterizing Cannabis Use and Perceived Benefit in a Tertiary Headache Center Patient Sample

Background and Objectives

Research suggests a potential role for cannabinoids in the etiology and treatment of migraine. However, there is a paucity of research on usage patterns and perceived benefits of cannabis use in clinical headache patient populations.

Methods

Patients from a tertiary headache center completed a 1-time online survey regarding cannabis use patterns and perceived benefits of cannabis-based products in treating migraine symptoms, clinical features, and risk factors (e.g., depression, sleep disturbance). Descriptive analyses were performed.

Results

Data were collected from 1373 patients (response rate 25.4% [1,373/5,400]), with 55.7% reporting cannabis-based product use in the past 3 years and 32.5% indicating current use. The most frequently cited reasons for cannabis-based product use were treating headache (65.8%) and sleep concerns (50.8%). Inhaled products (i.e., smoked/vaped) and edibles were the most commonly reported delivery methods, with THC/CBD (∆9 tetrahydrocannabinol/cannabidiol) blends as the most-cited product composition. A majority of participants reported cannabis-related improvements in migraine headache characteristics (i.e., intensity: 78.1%; duration: 73.4%; frequency: 62.4%), nausea (56.3%), and risk factors (sleep disturbance: 81.2%; anxiety: 71.4%; depression: 57.0%). Over half (58.0%) of the respondents reported only using cannabis products when experiencing a headache, while 42.0% used cannabis most days/daily for prevention. Nearly half (48.9%) of the respondents reported that cannabis use contributed to a reduction in medication amount for headache treatment, and 14.5% reported an elimination of other medications. A minority (20.9%) of participants reported experiencing side effects when using cannabis products for headache, most commonly fatigue/lethargy. For those participants who reported no use of cannabis-based products in the previous 3 years, approximately half indicated not knowing what cannabis product to take or the appropriate dosage.

Discussion

This is the largest study to date to document cannabis product usage patterns and perceived benefits for migraine management in a clinical headache patient sample. A majority of patients surveyed reported using cannabis products for migraine management and cited perceived improvements in migraine characteristics, clinical features, and associated risk factors. The findings warrant experimental trials to confirm the perceived benefits of cannabis products for migraine prevention and treatment.

Pearls for Starting a Headache Surgery Practice in Academic and Private Practice

There has been a growing body of evidence indicative of the effectiveness of headache surgery in treating patients with refractory headache disorders. The American Society of Plastic Surgeons issued a Policy Statement in 2018 stating that peripheral nerve decompression surgery for the treatment of refractory chronic headache disorders in select patients is considered a standard of care treatment. This endorsement sparked the interest of numerous plastic surgeons into initiating their own headache surgery practices. However, establishing a headache surgery clinic introduces challenges and considerations. This report outlines the key pillars for launching a successful headache surgery practice in academic and private practice environments.

Peripheral Endocannabinoid Components and Lipid Plasma Levels in Patients with Resistant Migraine and Co-Morbid Personality and Psychological Disorders: A Cross-Sectional Study

Resistant migraine characterizes those patients who have failed at least three classes of migraine prophylaxis. These difficult-to-treat patients are likely to be characterized by a high prevalence of psychological disturbances. A dysfunction of the endocannabinoid system (ECS), including alteration in the levels of endocannabinoid congeners, may underlie several psychiatric disorders and the pathogenesis of migraines. Here we explored whether the peripheral gene expression of major components of the ECS and the plasma levels of endocannabinoids and related lipids are associated with psychological disorders in resistant migraine. Fifty-one patients (age = 46.0 ± 11.7) with resistant migraine received a comprehensive psychological evaluation according to the DSM-5 criteria. Among the patients, 61% had personality disorders (PD) and 61% had mood disorders (MD). Several associations were found between these psychological disorders and peripheral ECS alterations. Lower plasma levels of palmitoiletanolamide (PEA) were found in the PD group compared with the non-PD group. The MD group was characterized by lower mRNA levels of diacylglycerol lipase α (DAGLα) and CB2 (cannabinoid-2) receptor. The results suggest the existence of peripheral dysfunction in some components of the ECS and an alteration in plasma levels of PEA in patients with resistant migraine and mood or personality disorders.

Resistant and refractory migraine: clinical presentation, pathophysiology, and management

Migraine is a leading cause of disability worldwide. A minority of individuals with migraine develop resistant or refractory conditions characterised by ≥ 8 monthly days of debilitating headaches and inadequate response, intolerance, or contraindication to ≥3 or all preventive drug classes, respectively. Resistant and refractory migraine are emerging clinical definitions stemming from better knowledge of the pathophysiology of migraine and from the advent of migraine-specific preventive treatments. Resistant migraine mostly results from drug failures, while refractory migraine has complex and still unknown mechanisms that impair the efficacy of preventive treatments. Individuals with resistant migraine can be treated with migraine-specific preventive drugs. The management of refractory migraine is challenging and often unsuccessful, being based on combinations of different drugs and non-pharmacological treatment. Future research should aim to identify individuals at risk of developing treatment failures, prevent the condition, investigate the mechanisms of refractoriness to treatments, and find effective treatment strategies.

Ketamine in neuropsychiatric disorders: an update

The discovery of ketamine as a rapid-acting antidepressant led to a new era in the development of neuropsychiatric therapeutics, one characterized by an antidepressant response that occurred within hours or days rather than weeks or months. Considerable clinical research supports the use of-or further research with-subanesthetic-dose ketamine and its (S)-enantiomer esketamine in multiple neuropsychiatric disorders including depression, bipolar disorder, anxiety spectrum disorders, substance use disorders, and eating disorders, as well as for the management of chronic pain. In addition, ketamine often effectively targets symptom domains associated with multiple disorders, such as anxiety, anhedonia, and suicidal ideation. This manuscript: 1) reviews the literature on the pharmacology and hypothesized mechanisms of subanesthetic-dose ketamine in clinical research; 2) describes similarities and differences in the mechanism of action and antidepressant efficacy between racemic ketamine, its (S) and (R) enantiomers, and its hydroxynorketamine (HNK) metabolite; 3) discusses the day-to-day use of ketamine in the clinical setting; 4) provides an overview of ketamine use in other psychiatric disorders and depression-related comorbidities (e.g., suicidal ideation); and 5) provides insights into the mechanisms of ketamine and therapeutic response gleaned from the study of other novel therapeutics and neuroimaging modalities.

Combination of anti-CGRP/CGRP-R mAbs with onabotulinumtoxin A as a novel therapeutic approach for refractory chronic migraine: a retrospective study of real-world clinical evidence and a protocol for a double-blind, randomized clinical trial to establish the efficacy and safety

Chronic migraine is a disabling neurovascular disorder that ranks amongst the top causes of years lived with disability worldwide. The duration and the frequency of migraine affect cognitive and affective domains, inducing worsening of memory, executive functions, orientation and causing anxiety. Population-based studies report a worrying level of resistance to treatments. Therefore, this study aims: 1) to assess efficacy of monoclonal antibodies (mAbs) directed towards the calcitonin gene-related peptide (CGRP) or its receptor (CGRP-R) for chronic migraine resistant to current preventatives; 2) to design a clinical trial protocol to evaluate the efficacy and safety of combination therapy utilizing anti-CGRP/CGRP-R together with onabotulinumtoxin A in patients suffering from resistant chronic migraine; 3) to provide a molecular rationale for combination therapy. A controlled trial is warranted as pooled analysis of real-world data from our group highlighted that combined treatment provides ≥50% reduction vs. baseline (onabotulinumtoxin A) of monthly headache days (MHDs) in up to 58.8% of patients, but there has been only sparse application of this combined therapy to date. The mAbs chosen are: erenumab, because its combination effect with onabotulinumtoxin A improved symptoms in 65% of patients; eptinezumab, due to its faster action. The results highlight that early diagnosis of migraine improves therapeutic outcomes with mAbs alone, confirming their effectiveness and the need for an adequately powered clinical trial evaluating the safety and potential superior effectiveness of eptinezumab/erenumab and onabotulinumtoxin A together.

Study of severe migraine in general medicine

OBJECTIVE

To evaluate the criteria of severe migraine in a general population consulting a general practitioner (GP) and to evaluate assessment of migraine severity in the migraine patient as well as treating physicians' knowledge of their patient's migraine and its severity.

METHODS

We questioned voluntary headache patients who had an appointment with a GP about the severity of their migraine using recognized scores - HIT-6 and MIDAS - as well as with a specific questionnaire created for the study. We compared the criteria for severe migraine with the patient's description of their symptoms, their HIT-6 score, their MIDAS score, and the GP's opinion, analyzing collected data using means and standard deviations.

RESULTS

We found that 152 out of 942 headache patients questioned in the general medicine setting met the criteria of "strict migraine", corresponding to 10.3% prevalence. Seventy-one out of 100 patients (71%) with migraine who filled out in the questionnaire completely had what is characterized as "severe migraine". Forty-one (57%) of the 71 severe migraine patients presented the strict criteria. Additionally, 21 of the 29 (72%) patients with a non-severe diagnosis agreed that their headache was non-severe. When the HIT-6 score was stratified above 65, correspondence between the questionnaire-derived diagnosis and patient perception of severity was observed in 36 of the 58 (62%) with severe migraine. Finally, participating GPs were aware of their patient's migraine for 60% of patients with migraine. GPs correctly classified the severity of their patient's migraine for 55 (36%) patients.

CONCLUSION

GP education and training about migraine remain a public health issue. The diagnosis of severe migraine is necessary for proper patient management. Current criteria for severe migraine are not robust enough; we propose a modification of the criteria.

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.

Safety of Onabotulinumtoxin A in Chronic Migraine: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Some 14% of global prevalence, based on high-income country populations, suffers from migraine. Chronic migraine is very disabling, being characterized by at least 15 headache days per month of which at least 8 days present the features of migraine. Onabotulinumtoxin A, targeting the machinery for exocytosis of neurotransmitters and neuropeptides, has been approved for use in chronic migraine since 2010. This systematic review and meta-analysis appraises the safety of onabotulinumtoxin A treatment for chronic migraine and the occurrence of treatment-related adverse events (TRAEs) in randomized, clinical studies in comparison with placebo or other comparators and preventative treatments according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieved 888 total records. Nine studies are included and seven were eligible for meta-analysis. The present study demonstrates that toxin produces more TRAEs than placebo, but less than oral topiramate, supporting the safety of onabotulinumtoxin A, and highlights the heterogeneity of the studies present in the literature (I2 = 96%; p < 0.00001). This points to the need for further, adequately powered, randomized clinical trials assessing the safety of onabotulinumtoxin A in combination with the newest treatment options.

Regional Targeted Subcutaneous Injection of Botulinum Neurotoxin Type A in Refractory Chronic Migraine: A Randomized, Double-Blind, Placebo-Controlled Study

In this randomized, double-blind, placebo-controlled study, we evaluated the efficacy of an individualized technique of subcutaneous injection of botulinum toxin type A (BoNT-A) targeted (SjBoT) to the occipital or trigeminal skin area in non-responder patients with chronic migraine (CM). Patients who had not previously responded to at least two treatments of intramuscular injections of BoNT-A were randomly assigned (2:1) to receive two subcutaneous administrations of BoNT-A (up to 200 units) with the SjBoT injection paradigm or placebo. Following the skin area where the maximum pain began, treatment was given in the trigeminal or occipital region bilaterally. The primary endpoint changed in monthly headache days from baseline to the last 4 weeks. Among 139 randomized patients, 90 received BoNT-A and 49 received placebo, and 128 completed the double-blind phase. BoNT-A significantly reduced monthly headache days versus placebo (-13.2 versus -1.2; p < 0.0001) in the majority of patients who had cutaneous allodynia. Other secondary endpoints, including measures for disability (Migraine Disability Assessment questionnaire from baseline 21.96 to 7.59 after treatment, p = 0.028), also differed. Thus, in non-responder patients with CM, BoNT-A significantly reduced migraine days when administered according to the "follow the origin of maximum pain" approach using SjBoT injection paradigm.

Eptinezumab for adolescents with chronic refractory headache: A retrospective chart review

OBJECTIVE

To evaluate the safety and efficacy of eptinezumab for the treatment of chronic refractory headache in adolescents.

BACKGROUND

Chronic refractory headache can lead to school absences and impaired quality of life in adolescents, and currently there are no pharmacologic treatments with level A evidence for headache prevention for this population. While observational data suggest that monoclonal antibodies to calcitonin gene-related peptide or its receptor may be helpful for adolescents who have refractory primary headache disorders, evidence is lacking for the use of eptinezumab.

METHODS

This was a single-center, retrospective chart review. Demographic and headache phenotypic data were collected. Outcome measures included headache intensity and frequency pre- and post-infusion(s), and improvement in function or in associated symptoms. Adverse events were also collected.

RESULTS

Nine patients with chronic migraine and two with new daily persistent headache received a first dose of 100 mg of eptinezumab. All of them had daily headache and nine had continuous headache at baseline. After the first infusion of 100 mg, two patients were no longer having daily headache, one patient stopped having continuous headache, and four patients noted headache intensity reduction. Additionally, one patient described a reduction in nausea and vomiting, and another patient noted improvement in function. Six patients received a second eptinezumab infusion of 100 mg, three had a third one, and one patient had four infusions of 100 mg. After the second infusion, one patient noted reduction in headache frequency, one experienced lower headache intensity, and two described pain "improving." With the third and fourth infusions, patients continued to report improvement in headache intensity. Subsequent infusions of 300 mg resulted in further reductions in headache frequency and intensity for some patients. Eptinezumab was overall well tolerated.

CONCLUSION

While this was a small sample, findings suggest that eptinezumab may be a safe and effective treatment for chronic, refractory headache in adolescents.

Long-Term Follow-Up Safety and Effectiveness of CT-Guided Radiofrequency Thermocoagulation of Sphenopalatine Ganglion in Refractory Headache Treatment

OBJECTIVE

The purpose of this study was to evaluate the effectiveness and safety of computed tomography (CT)-guided radiofrequency thermocoagulation (RFTA) of the sphenopalatine ganglion (SPG) for patients with refractory headache.

METHODS

A total of 14 patients with refractory migraine and 10 patients with cluster headache (CH) who underwent CT-guided SPG RF between May 2019 and August 2021 at the Jiaxing First Hospital, located in Jiaxing City, Zhejiang Province, China, were included and analyzed in this retrospective cohort study. Pain score, sleep quality scores, and treatment effects were observed before operation as well as 1 day and 1, 3, 6, 12, and 24 months after surgery. Also, the incidence of facial numbness at different timepoints after operation was evaluated.

RESULTS

The frequency and duration of attacks decreased after treatment in patients with migraine, and the shortening of the cluster period and the prolongation of the remission period after treatment in patients with CH indicated that the treatment was effective. The numeric rating scale (NRS) ranged from 0 to 10, where 0 meant no pain and 10 meant the worst imaginable pain. The NRS of patients at 1 day and 1, 3, 6, 12, and 24 months after surgery was significantly lower than before operation (P < 0.05). The treatment of patients with migraine and CH was effective. The overall incidence of numbness in patients with migraine and the total incidence of numbness in patients with CH was recorded. The total incidence of numbness decreased gradually, but no significant difference was detected in the incidence of numbness between the two groups (P > 0.05). No serious adverse reactions, such as orthostatic hypertension, intracranial infection, and visual disturbance, occurred in the patients after operation.

CONCLUSION

CT-guided RFTA of the SPG significantly relieves headache symptoms in patients with refractory migraine and CH. It has the advantages of rapid onset, long duration, and a safe and reliable treatment process, making it worthy of clinical application.

Refractory Headaches

Medication overuse headache (MOH), new daily persistent headache (NDPH), and persistent refractory headache attributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection represent a significant burden in terms of disability and quality of life, and a challenge in terms of definition, pathophysiology, and treatment. Regarding MOH, prevention without withdrawal is not inferior to prevention with withdrawal. Preventive medications like topiramate, onabotulinumtoxinA, and calcitonin gene-related peptide (CGRP) monoclonal antibodies improve chronic migraine with MOH regardless of withdrawal. The differential diagnosis of NDPH is broad and should be carefully examined. There are no guidelines for the treatment of NDPH, but options include a short course of steroids, nerve blocks, topiramate, nortriptyline, gabapentin, CGRP monoclonal antibodies, and onabotulinumtoxinA. The persistence of headache 3 months after SARS-CoV2 infection is a predictor of poor prognosis.

Early Onset Diffusion Abnormalities in Refractory Headache Disorders

Objective

This study sought to determine if individuals with medically refractory migraine headache have volume or diffusion abnormalities on neuroimaging compared to neurotypical individuals.

Background

Neuroimaging biomarkers in headache medicine continue to be limited. Early prediction of medically refractory headache and migraine disorders could result in earlier administration of high efficacy therapeutics.

Methods

A single-center, retrospective, case control study was performed. All patients were evaluated clinically between 2014 and 2018. Individuals with medically refractory migraine headache (defined by ICDH-3 criteria) without any other chronic medical diseases were enrolled. Patients had to have failed more than two therapeutics and aura was not exclusionary. The initial MRI study for each patient was reviewed. Multiple brain regions were analyzed for volume and apparent diffusion coefficient values. These were compared to 81 neurotypical control patients.

Results

A total of 79 patients with medically refractory migraine headache were included and compared to 74 neurotypical controls without headache disorders. Time between clinical diagnosis and neuroimaging was a median of 24 months (IQR: 12.0–37.0). Comparison of individuals with medically refractory migraine headache to controls revealed statistically significant differences in median apparent diffusion coefficient (ADC) in multiple brain subregions (p < 0.001). Post-hoc pair-wise analysis comparing individuals with medically refractory migraine headache to control patients revealed significantly decreased median ADC values for the thalamus, caudate, putamen, pallidum, amygdala, brainstem, and cerebral white matter. No volumetric differences were observed between groups.

Conclusions

In individuals with medically refractory MH, ADC changes are measurable in multiple brain structures at an early age, prior to the failure of multiple pharmacologic interventions and the diagnosis of medically refractory MH. This data supports the hypothesis that structural connectivity issues may predispose some patients toward more medically refractory pain disorders such as MH.

Advances in pharmacotherapy for the prophylactic treatment of resistant and refractory migraine

INTRODUCTION

Refractory migraine is associated with low quality of life and great socioeconomic burden. Despite high need for effective, tolerable preventive therapies, there has been little research on potential therapeutic options. Monoclonal antibodies (mAbs) against Calcitonin Gene-Related Peptide (CGRP) are the first preventive therapeutic approach for migraine based on the underlying pathophysiology.

AREAS COVERED

Following a brief introduction into the term 'refractory migraine,' the authors reviewavailable treatment options, focusing on current phase III trials of substances acting on the CGRP pathway.

EXPERT OPINION

No uniform definition for refractory migraine is available. The vast majority of proposals recommend treatment failure of 2-4 drug classes as a key diagnostic criterion. Phase III studies on CGRP-(receptor) mAbs demonstrated excellent efficacy and tolerability in patients with chronic and episodic migraine including subjects with multiple unsuccessful conventional therapy attempts. However, more comparator trials showing superiority of mAbs versus oral preventatives, such as the HER-MEs study are needed. In summary, with the CGRP antibodies, a group of drugs has entered the market which will most likely not only significantly improve the quality of life of many individual migraine patients but could also reduce indirect health-care costs associated with migraine by reducing recurrent medical consultations.

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Treatment of resistant chronic migraine with anti-CGRP monoclonal antibodies: a systematic review

BACKGROUND

Resistant chronic migraine is a highly disabling condition which is very difficult to treat. The majority of the treatments for migraine prophylaxis are nonspecific and present weak safety profiles, leading to low adherence and discontinuation. Currently, monoclonal antibodies (mAb) targeting the trigeminal sensory neuropeptide, calcitonin gene-related peptide (CGRP), are available for migraine prophylaxis being the first drugs developed specifically to target migraine pathogenesis. The main objective of the current work is to carry out a systematic review of randomised controlled trials that specifically analyse the effectivity and safety of anti-CGRP mAb, comparatively to placebo, in patients with resistant chronic migraine and possibly fill the literature gap or be a source of information to health professionals. Additionally the current knowledge on migraine, particularly resistant chronic migraine, was revisited and summarised.

METHODS

Literature search was carried out on MEDLINE, Scopus, Science Direct and ClinicalTrials.gov database, from inception to December 2021. Articles were selected according to prespecified criteria of inclusion and exclusion. Efficacy and safety outcomes included were: change from baseline in monthly migraine days (MMD); ≥50% reduction of MMD values from baseline; change from baseline in monthly acute migraine-specific medication days (MAMD); Migraine-specific Quality of Life Questionnaire (MSQ); and registered adverse events. Additionally, we used the Cochrane risk of bias tool (RoB 2) to assess the risk of bias of the included studies.

RESULTS

Four studies were included in this systematic review, involving 2811 resistant chronic migraine patients, 667 in a study using erenumab, 838 in a study using fremanezumab and 1306 in two studies using galcanezumab. When compared to placebo, all investigated anti-CGRP mAb and respective doses demonstrate effectiveness in decreasing MMD, reducing acute medication use and improving the MSQ scores, including, sometimes, reversion of chronic to episodic migraine (efficacy outcomes). Regarding the safety outcomes, the number and type of adverse events did not differ between anti-CGRP mAb-treated and placebo groups.

CONCLUSIONS

Anti-CGRP or anti-CGRP receptor monoclonal antibodies are a promising preventive migraine therapy which can be particularly useful for resistant chronic migraine patients.

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Efficacy and Safety of Repetitive Intravenous Sodium Valproate in Pediatric Patients With Refractory Chronic Headache Disorders: A Retrospective Review

BACKGROUND

Chronic headache disorders can cause substantial disability and be treatment refractory. Often, these patients are excluded from clinical trials with leaving little evidence to guide treatment. In adults, divalproex sodium is an effective preventive migraine treatment.

METHODS

All pediatric patients admitted for first-time sodium valproate infusions to treat refractory, chronic migraine (CM), new daily persistent headache, or persistent headache attributed to head trauma from January 2017 to October 2020 were identified for review. Each patient underwent a standardized, 4-day protocol. A new preventive was started one week after discharge. Data on headache frequency, severity, and acute medication use were collected through preadmission and postadmission clinic notes. Safety and tolerability were evaluated. Results were evaluated using descriptive statistics and compared with paired t-tests.

RESULTS

Forty-five patients were identified for review. Patients with CM had a median of 7 previous preventive trials, and 85% had previously received alternative intravenous treatment for headache. Baseline headache pain significant decreased from 6.9/10 to 5.4/10 by 7-week postadmission follow up, (95% confidence interval = -0.7 to -2.4), P < 0.001. Use of medications for acute headache treatment decreased significantly from 2.1 days/week to 1.5 days/week, (95% confidence interval = -0.3 to -1), P < 0.001. Baseline headache frequency did not significantly change. At postadmission follow-up, 26 of 39 (67%) patients saw improvements in headache frequency, headache intensity, and/or acute pain medication usage. There were no serious adverse events.

CONCLUSIONS

Repetitive sodium valproate infusions were well tolerated and significantly reduced baseline headache intensity and acute medication usage in pediatric patients with refractory, chronic headache disorders.

Beyond the Raskin Protocol: Ketamine, Lidocaine, and Other Therapies for Refractory Chronic Migraine

PURPOSE OF REVIEW

The purpose of this review is to discuss the available evidence and therapeutic considerations for intravenous drug therapy for refractory chronic migraine.

RECENT FINDINGS

In carefully monitored settings, the inpatient administration of intravenous lidocaine and ketamine can be successful in treating refractory chronic migraine. Many patients with refractory chronic migraine have experienced treatment failure with the Raskin protocol. The use of aggressive inpatient infusion therapy consisting of intravenous lidocaine or ketamine, along with other adjunctive medications, has become increasingly common for these patients when all other treatments have failed. There is a clear need for prospective studies in this population comprised of patients who have largely been excluded from other studies.

Treatment of chronic migraine and neck pain with cognitive-behavioral therapy. Case report

The article presents a case of a patient with chronic migraine, neck pain, drug-induced headache and generalized anxiety disorder. We analyzed the relationship between migraines and neck pain. The article discusses the interdisciplinary treatment of chronic migraine, which included educational conversation, detoxification therapy, rational relief of migraine attacks, preventive pharmacotherapy and cognitive-behavioral therapy. The latter allowed to change the patient's perception of the disease, reduce anxiety and catastrophization of pain, cope with fears, stop taking benzodiazepines, reduce the intake of pain relievers, and increase daily activity and productivity at work. Clinical efficacy (reduction in the frequency of headaches per month by 50% or more) was achieved after 3 months of treatment. Long-term (12 months) follow-up of the patient showed long-term clinical effect of the interdisciplinary treatment.

Refractory migraine profile in CGRP-monoclonal antibodies scenario

Objective

Refractory migraine (Ref‐M) represents a conundrum that headache experts have to face with. We aim to investigate whether a peculiar profile may characterize patients with Ref‐M according to 2020 European Headache Federation criteria. Furthermore, to substantiate a dysfunctional dopaminergic pathway involvement in these patients, we explored the effectiveness of olanzapine.

Materials & Methods

Eighty‐four patients (fitting previous Ref‐M criteria of the 2014) were treated with erenumab for six months. Differences between clinical and demographic features of responder (Ref‐M according to 2014 criteria) and not‐responder (Ref‐M according to 2020 criteria) patients to CGRP‐mAbs were investigated and their predictive values assessed. In fifteen patients with Ref‐M not responders to CGRP‐mAbs, olanzapine was administered (5 mg/die) for 3 months and frequency and pain intensity of migraine attacks were estimated.

Results

Patients with Ref‐M not responsive to CGRP‐mAbs (29/84) when compared with Ref‐M responsive to CGRP‐mAbs showed higher baseline frequency of migraine attacks, medication overuse and pain catastrophizing scale (PCS) scores. Logistic regression analyses showed that frequency of attacks, medication overuse and PCS score represent independent negative predictors of CGRP‐mAbs response. A ≥50% reduction of headache days/month was observed after olanzapine treatment in 67% of patients with Ref‐M not responsive to CGRP‐mAbs.

Conclusions

We outline that higher frequency of migraine attacks, medication overuse and pain catastrophizing characterize patients with Ref‐M not responsive to CGRP‐mAbs. In this frame, olanzapine effectiveness on frequency and pain intensity of migraine attacks supports the hypothesis that migraine refractoriness may be subtended by a prominent involvement of the dopaminergic pathway.

Real-life assessment of erenumab in refractory chronic migraine with medication overuse headache

OBJECTIVE

To determine whether erenumab is effective and safe in refractory chronic migraine with medication overuse headache.

METHODS

In this prospective, multicentric, real-life study, chronic migraine with medication overuse headache patients who received erenumab were recruited. Study inclusion was limited to patients who previously failed onabotulinumtoxinA in addition to at least three other pharmacological commonly used migraine preventive medication classes.

RESULTS

Of 396 patients who received erenumab, 38% (n = 149) met inclusion criteria. After 3 months, 51% (n = 76) and 20% (n = 30) patients achieved ≥ 50% and ≥ 75% reduction in monthly headache days, respectively. Monthly pain medications intake decreased from 46.1 ± 35.3 to 16.8 ± 13.9 (p < 0.001), while monthly headache days decreased from 25.4 ± 5.4 to 14.1 ± 8.6 (p < 0.001). Increasing efficacy of erenumab over the study period was observed. Allodynia was a negative predictive factor of erenumab response (odds ratio = 0.47; p = 0.03). Clinical conversion to episodic migraine with no medication overuse was observed in 64% (n = 96) patients. No serious adverse events were observed.

CONCLUSIONS

Erenumab reduced significantly migraine frequency and pain medication intake in refractory chronic migraine with MOH patients.

Severe migraine and its control: A proposal for definitions and consequences for care

Currently many patients with severe migraine do not receive appropriate treatment and are never referred to specialist headache centres. On the other hand, specialist headache centres are frequently attended by patients whose migraines could be managed adequately in the community. One reason for this may be the absence of standardised definitions of migraine severity and control and of a treatment algorithm for orientating difficult-to-treat patients to specialist headache centres. Based on a review of the relevant literature and consensus meetings, proposals have been made for these items. We propose that migraine should be considered severe if headache frequency is at least eight migraine days per month or, if headaches are less frequent, the HIT-6 score is ≥60 or ≥50% of headaches require complete interruption of activity. The proposed definition of migraine control is defined on the basis of appropriate response to acute headache therapy and to preventative therapy. A treatment algorithm is proposed to assess migraine control regularly and to adapt therapy accordingly. These proposals may contribute to developing and testing strategies for management of severe disease with appropriate and effective preventive treatment strategies. With the anticipated introduction of new possibilities for migraine prevention in the near future, the time is ripe for a holistic approach to migraine management.

Effectiveness of ketogenic diet in treatment of patients with refractory chronic migraine

BACKGROUND AND PURPOSE

Ketogenic diet (KD) is based on restriction of carbohydrate intake. Metabolism is forced to obtain energy starting from β-oxidation of fatty acids which, turned into ketone bodies, can also be used by central nervous system (CNS). KD use in treatment of chronic migraine has recently been considered. We set out to verify modification of symptoms in patients with refractory chronic migraine in response to KD.

METHODS

Fifty patients were enrolled of which 38 completed the procedures the study and 23 were considered in the statistics. All of the patients considered in our study were affected by medication overuse headache (MOH). They were on a KD for 3 months. The following parameters have been checked at t = 0 and every 30 days for 6 months: migraine episode length (n. hours/day), frequency (n. days/month), level of pain of every episode measured on a scale from 1 to 3 (1 = mild; 2 = moderate; 3 = severe), and n. analgesic drugs taken/month.

RESULTS

Days with symptoms decreased from 30 (median value) to 7.5 with p < 0.0001. The duration of the migraine episodes decreased from 24 h (median value) to 5.5 h with p < 0.0016. The patients' pain level, initially at maximum value for 83% of the participants, improved for 55% of them (p < 0.0024). The number of drugs taken in a month decreased from 30 doses (median value) to 6 doses.

CONCLUSIONS

It can be stated that a 3-month KD resulted in a reduction of painful symptoms of drug refractory chronic migraine. This result may suggest an improvement in quality of life of the patients, even without a tabulated data collection.

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.

European headache federation consensus on the definition of resistant and refractory migraine : Developed with the endorsement of the European Migraine & Headache Alliance (EMHA)

INTRODUCTION

Despite advances in the management of headache disorders, some patients with migraine do not experience adequate pain relief with acute and preventive treatments. It is the aim of the present document to provide a definition of those migraines which are difficult-to-treat, to create awareness of existence of this group of patients, to help Healthcare Authorities in understanding the implications, and to create a basis to develop a better pathophysiological understanding and to support further therapeutic advances.

MAIN BODY

Definitions were established with a consensus process using the Delphi method. Patients with migraine with or without aura or with chronic migraine can be defined as having resistant migraine and refractory migraine according to previous preventative failures. Resistant migraine is defined by having failed at least 3 classes of migraine preventatives and suffer from at least 8 debilitating headache days per month for at least 3 consecutive months without improvement; definition can be based on review of medical charts. Refractory migraine is defined by having failed all of the available preventatives and suffer from at least 8 debilitating headache days per month for at least 6 consecutive months. Drug failure may include lack of efficacy or lack of tolerability. Debilitating headache is defined as headache causing serious impairment to conduct activities of daily living despite the use of pain-relief drugs with established efficacy at the recommended dose and taken early during the attack; failure of at least two different triptans is required.

CONCLUSIONS

We hope, that the updated EHF definition will be able to solve the conflicts that have limited the use of definitions which have been put forward in the past. Only with a widely accepted definition, progresses in difficult-to-treat migraine can be achieved. This new definition has also the aim to increase the understanding of the impact of the migraine as a disease with all of its social, legal and healthcare implications. It is the hope of the EHF Expert Consensus Group that the proposed criteria will stimulate further clinical, scientific and social attention to patients who suffer from migraine which is difficult-to-treat.

A prospective real-world analysis of erenumab in refractory chronic migraine

BACKGROUND

Clinical trials have shown the safety and clinical superiority of erenumab compared to placebo in chronic migraine (CM). The aim of this analysis is to evaluate the effectiveness and tolerability of erenumab in a real-world setting in patients with refractory CM.

METHODS

This is a prospective single centre real-world audit conducted in patients with CM with and without medication overuse, refractory to established preventive medications, who received monthly erenumab for 6 months.

RESULTS

Of 164 patients treated, 162 patients (female = 135, mean age 46 ± 14.3 years old) were included in the audit. Patients had failed a mean of 8.4 preventive treatments at baseline and 91% of patients failed Botulinum toxin type A at baseline. The mean reduction in monthly migraine days was 6.0 days at month 3 (P = 0.002) and 7.5 days at month 6 (P < 0.001) compared to baseline. The mean reduction in monthly headache days was 6.3 days (P < 0.001) at month 3 and 6.8 days (P < 0.001) at month 6. At month 3, 49%, 35% and 13% and at month 6, 60%, 38% and 22% of patients obtained at least a 30%, 50% and 75% reduction in migraine days, respectively. The percentage of patients with medication overuse was reduced from 54% at baseline to 20% at month 3 and to 25% at month 6. Compared to baseline, the mean reduction of Headache Impact Test-6 score was 7.7 points at month 3 (from 67.6 ± 0.4 to 59.9 ± 0.9) (P < 0.001) and of 7.5 points at month 6 (60.1 ± 1.3) (P = 0.01). The percentage of patients with severe headache-related disability (HIT-6: 60-78) was reduced from 96% at baseline to 68% after three monthly treatments and to 59% after six treatments. At least one side effect was reported by 48% of patients at month 1, 22% at month 3 and 15% at month 6. Constipation (20%) and cold/flu-like symptoms (15%) were the most frequent adverse events reported.

CONCLUSION

Erenumab may be an effective and well tolerated therapy for medically refractory CM patients with and without medication overuse.

Dual Therapy With Anti-CGRP Monoclonal Antibodies and Botulinum Toxin for Migraine Prevention: Is There a Rationale?

OBJECTIVE

To narratively review the pathophysiological rationale of dual therapy with anti-calcitonin gene-related peptide monoclonal antibodies and botulinum toxin type A in treatment-resistant chronic migraine prevention.

BACKGROUND

For the prevention of chronic migraine, several pharmacological therapies are available, including oral medications, botulinum toxin type A, and the newly approved monoclonal antibodies targeting calcitonin gene-related peptide or its receptor. However, monotherapy does not yield benefits in some affected individuals, which raises the question of whether dual therapy with monoclonal antibodies and botulinum toxin type A hold promise in patients with treatment-resistant chronic migraine.

METHOD

We searched MEDLINE for articles published from database inception to December 31st, 2019. Publications were largely selected from the past 10 years but commonly referenced and highly regarded older publications were not excluded.

RESULTS

Preclinical data suggest that anti-calcitonin gene-related peptide monoclonal antibodies and botulinum toxin type A have synergistic effects within the trigeminovascular system. Of note, findings indicate that fremanezumab - an antibody targeting the calcitonin gene-related peptide - mainly prevents the activation of Aδ-fibers, whereas botulinum toxin type A prevents the activation of C-fibers.

CONCLUSION

There is currently only indirect preclinical evidence to support a rationale for dual therapy with anti-calcitonin gene-related peptide monoclonal antibodies and botulinum toxin type A for chronic migraine prevention. Rigorous studies evaluating clinical efficacy, safety, and cost-effectiveness are needed.

Identifying and managing refractory migraine: barriers and opportunities?

The term refractory migraine has been used to describe persistent headache that is difficult to treat or fails to respond to standard and/or aggressive treatments. This subgroup of migraine patients are generally highly disabled and experience impaired quality of life, despite optimal treatments. Several definitions and criteria for refractory migraine have been published, but as yet, an accepted or established definition is not available. This article reviews the published criteria and proposes a new set of criteria. The epidemiology, pathophysiology and management options are also reviewed.

An open/pilot trial of cognitive behavioral therapy in Turkish patients with refractory chronic migraine

Cognitive behavioral therapy (CBT) for pain management is a therapy that aims to modify thoughts and behavior to be more realistic and balanced. There are limited number of studies to assess the efficacy of CBT for patients with pharmacotherapy-resistant chronic migraine in our population. We aimed to invstigate the effects of CBT for patients with refractory chronic migraine on pain attack frequency, disability, severity, anxiety and depression. Fourteen patients with refractory chronic migraine who were referred from the headache clinic to the psychiatry department and regularly attended CBT sessions at least once every 2 weeks for at least 6 months, were included in the study. After 2 sessions of psychiatric evaluation, the subjects had 12 40-min CBT sessions and were given relaxation exercises. The Hamilton depression and anxiety inventories, visual analogue scale for assessing the severity of pain, and the Migraine disability assessment (MIDAS) test were used before and after CBT. The mean Hamilton depression scores before and after CBT were 29.07 ± 7.74 and 14.21 ± 7.7, respectively (p < 0.0001). The mean Hamilton anxiety scores before and after CBT were 26.8 ± 11.7 and 11.7 ± 2.6, respectively (p < 0.0001). The mean VAS scores before and after CBT were 8.07 ± 0.91 and 3.71 ± 1.32, respectively (p < 0.0001). The mean MIDAS scores before and after CBT were 55.5 ± 20.4 and 20.12 ± 16.6, respectively (p < 0.0001). Our results showed that CBT had made a statistically significant difference on pain severity, number of migraine attacks and disability in patients with refractory chronic migraine. CBT should be considered in this patient group.

Prediction of patient's response to OnabotulinumtoxinA treatment for migraine

Migraine affects the daily life of millions of people around the world. The most well-known disabling symptom associated with this illness is the intense headache. Nowadays, there are treatments that can diminish the level of pain. OnabotulinumtoxinA (BoNT-A) has become a very popular medication for treating migraine headaches in those cases in which other medication is not working, typically in chronic migraines. Currently, the positive response to Botox treatment is not clearly understood, yet understanding the mechanisms that determine the effectiveness of the treatment could help with the development of more effective treatments.

To solve this problem, this paper sets up a realistic scenario of electronic medical records of migraineurs under BoNT-A treatment where some clinical features from real patients are labeled by doctors. Medical registers have been preprocessed. A label encoding method based on simulated annealing has been proposed. Two methodologies for predicting the results of the first and the second infiltration of the BoNT-A based treatment are contempled. Firstly, a strategy based on the medical HIT6 metric is described, which achieves an accuracy over 91%. Secondly, when this value is not available, several classifiers and clustering methods have been performed in order to predict the reduction and adverse effects, obtaining an accuracy of 85%. Some clinical features as Greater occipital nerves (GON), chronic migraine time evolution and others have been detected as relevant features when examining the prediction models. The GON and the retroocular component have also been described as important features according to doctors.

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.

Non-invasive vagus nerve stimulation for the management of refractory primary chronic headaches: A real-world experience

Background

Non-invasive vagus nerve stimulation has initial evidence of efficacy in migraine and cluster headache. However, little is known about its role in the management of refractory chronic headaches.

Methods

We evaluated the preventive and abortive effects of non-invasive vagus nerve stimulation in 41 consecutive patients with refractory primary chronic headaches in an open-label prospective clinical audit. Headache diaries were used to collect clinical information. Those who obtained at least 30% reduction in headache days/episodes after three months of treatment were considered responders and were offered treatment continuation.

Results

Twenty-three patients with chronic migraine, 12 with chronic cluster headache, four with hemicrania continua and two with short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) were treated. Two of 23 chronic migraine patients, one of 12 chronic cluster headache patients, and two of four hemicrania continua patients were considered responders. None of the patients with SUNA benefited from the therapy. Two chronic migraine patients were able to reduce the pain severity of moderate migraines with non-invasive vagus nerve stimulation.

Conclusion

Non-invasive vagus nerve stimulation may not constitute an effective acute nor preventive treatment in refractory chronic primary headaches. The encouraging effect in hemicrania continua warrants further evaluation in larger studies.

[Diagnosis of refractory forms of chronic primary headache]

A number of patients with primary headaches remain insensitive or refractory to treatment despite correctly selected drugs, adequate therapeutic dose and duration of therapy. The importance of refractory problem is determined by the fact that patients are completely maladjusted, disabled, and keeping these patients is very difficult even for seasoned professionals. Determination of the correct tactics and success of the treatment depends, in the first place, on the correct diagnosis. This article discusses the diagnostic criteria for the most important forms such as refractory chronic migraine or refractory chronic cluster headache presented by experts of the European Headache Federation in two separate Consensus.

Interventional Treatment for Post-traumatic Headache

Post-traumatic headache (migraine) is the most common symptom of concussion and traumatic brain injury. An expert opinion-based review along with a literature review (PubMed) was conducted looking at known interventional procedures for post-traumatic headache using the keywords post-traumatic headache, post-traumatic migraine headache, concussion, mild traumatic brain injury, and traumatic brain injury and the following categories: mechanism, pathophysiology, treatment, physical therapy, neurostimulation, Botox@/Onabotulinum toxin, and surgical intervention. The results returned a total of 181 articles of which 52 were selected. None of the articles included randomized placebo-controlled studies, and most were either prospective or retrospective case analysis and/or review articles or consensus opinion papers, with most studies yielding positive results. Despite a lack of hard evidence, interventional procedures, alone or in combination, appear to be an effective treatment for post-traumatic headaches.

Intravenous ketamine for subacute treatment of refractory chronic migraine: a case series

BACKGROUND

Refractory migraine is a challenging condition with great impact on health related quality of life. Intravenous (IV) ketamine has been previously used to treat various refractory pain conditions. We present a series of patients with refractory migraine treated with intravenous ketamine in the hospital setting.

METHODS

Based on retrospective chart review, we identified six patients with refractory migraine admitted from 2010 through 2014 for treatment with intravenous ketamine. Ketamine was administered using a standard protocol starting with a dose of 0.1 mg/kg/hr and increased by 0.1 mg/kg/hr every 3 to 4 h as tolerated until the target pain score of 3/10 was achieved and maintained for at least 8 h. Visual Analogue Scale (VAS) scores at time of hospital admission were obtained as well as average baseline VAS scores prior to ketamine infusion. A phone interview was conducted for follow-up of migraine response in the 3 to 6 months following ketamine infusion.

RESULTS

The study sample had a median age of 36.5 years (range 29-54) and 83% were women. Pre-treatment pain scores ranged from 9 to 10. All patients achieved a target pain level of 3 or less for 8 h; the average ketamine infusion rate at target was 0.34 mg/kg/hour (range 0.12-0.42 mg/kg/hr). One patient reported a transient out-of-body hallucination following an increase in the infusion rate, which resolved after decreasing the rate. There were no other significant side effects.

CONCLUSION

IV ketamine was safely administered in the hospital setting to patients with refractory chronic migraine. Treatment was associated with short term improvement in pain severity in 6 of 6 patients with refractory chronic migraine. Prospective placebo-controlled trials are needed to assess short term and long-term efficacy of IV ketamine in refractory chronic migraine.

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.

Managing Chronic Headache Disorders

Headaches are a very common disorder, more common than asthma and diabetes combined. Migraine is the most common headache disorder, but it remains underdiagnosed and therefore undertreated. The treatment of migraines is divided into acute and prophylaxis. Patients who are experiencing 8 or more headaches a month or those who experience disability with their headaches as determined by the Migraine Disability Assistance Score or MIDAS should be placed on prophylaxis.

Evidence-Based Treatments for Adults with Migraine

Migraine, a significantly disabling condition, is treated with acute and preventive medications. However, some individuals are refractory to standard treatments. Although there is a host of alternative management options available, these are not always backed by strong evidence. In fact, most of the drugs used in migraine were initially designed for other purposes. Whilst effective, the benefits from these medications are modest, reflecting the need for newer and migraine-specific therapeutic agents. In recent years, we have witnessed the emergence of novel treatments, of which noninvasive neuromodulation appears to be the most attractive given its ease of use and excellent tolerability profile. This paper reviews the evidence behind the available treatments for migraine.

OnabotulinumtoxinA treatment for chronic migraine: experience in 52 patients treated with the PREEMPT paradigm

OnabotulinumtoxinA (OnabotA) was approved for treatment of chronic migraine (CM) after publication of PREEMPT trials. Thus, we set out to evaluate the efficacy of OnabotA in a series of patients with CM treated according to the PREEMPT protocol.

In May 2012 we began to offer OnabotA to patients with CM who did not respond to topiramate and at least one other preventive therapy (beta blocker and/or calcium channel antagonist). We prospectively recorded demographic data and the characteristics of migraine, and we assessed the modifications in monthly headache and migraine days, as well as the number of days of symptomatic medication and triptan intake.

By September 2014 we had treated 52 patients (8 male, 44 female), whose age at treatment onset was 42.8 ± 12.7 years (range: 16–71) and age at migraine onset was 16.8 ± 7.8 years (3–32). In 43 of these patients (82.7%) symptomatic overuse of medication was observed at the onset of treatment. A total of 168 procedures were performed and after the first session, we observed a significant reduction in all the variables considered. Twelve (23.1%) patients failed to perceive a positive effect after the first procedure and it was not repeated in 4 of them. By contrast, there was a significant decreasing in all the variables evaluated compared to the baseline in the 39 patients that received a second series of injections.

The use of OnabotA according to the PREEMPT paradigm is an effective treatment in patients with chronic migraine in a real-life setting.

Comment on: Martelletti et al. Refractory chronic migraine: a consensus statement on clinical definition from the European Headache Federation

In this letter, we present the Austrian proposal for diagnostic criteria of refractory chronic migraine and we discuss the consensensus statement of the European Headache Feaderation. We focus in particular on the definition of adequate prophylactic treatment, the management of medication overuse and the requirement for CSF analyses in patients with refractory chronic migraine. In our proposal, the criteria for adequate treatment and recommendations for dealing with medication overuse are more explicit than in the EHF proposal, whereas the requirements for CSF analyses and measurement of CSF pressure are not as strict.