Antiepileptics other than gabapentin, pregabalin, topiramate, and valproate for the prophylaxis of episodic migraine in adults

Efficacy and safety of levetiracetam for migraine prophylaxis in children: a systematic review and meta-analysis

Background

Levetiracetam (LEV), an antiepileptic drug, has been effective in adult migraine prevention but lacks extensive research in children. This study evaluates LEV's efficacy and safety for pediatric migraine prophylaxis.

Methods

We reviewed randomized controlled trials (RCTs) and non-RCTs in major databases through 8 January 2024, focusing on four efficacy endpoints and adverse drug reactions (ADRs). Data synthesis involved pooled relative risks or odds ratios for dichotomous outcomes and mean differences for continuous outcomes, using fixed- or random-effects models as appropriate.

Results

Eight studies with 190 participants showed that after taking LEV, the mean headache frequency decreased 5.19 per month (MD: -5.19, 95% CI: -7.11 to -3.27, p < 0.00001) and improved headache-free rates to 28% (95% CI: 0.17-0.41). More than 83% experienced a >50% reduction in monthly headache frequency. The migraine disability score decreased by 33.51 points (MD: -33.51, 95% CI: -38.46 to -28.55, p < 0.00001). ADR incidence did not significantly differ between LEV and control groups (RR: 1.06, 95% CI: 0.39 to 2.85, p = 0.91), with an overall ADR rate of 18% (95% CI: 0.13-0.24). The most common ADR was irritability (12%), leading to treatment discontinuation in 13% of cases (95% CI: 0.05-0.30).

Conclusion

LEV has shown good efficacy in preventing pediatric migraines. However, its safety requires further confirmation through more extensive and well-designed RCTs.

Systematic Review Registration

Identifier PROSPERO CRD42024497643.

Comparing Prophylactic Effect of Levetiracetam, Sodium Valproate, and Propranolol in Pediatric Migraine: A Randomized Clinical Trial

Objectives

Epidemiologic studies point to an increased prevalence of migraine in children in recent decades. Migraine treatment involves acute and prophylactic therapy. Recently, such anti-epileptic drugs as Levetiracetam have been used to treat adult migraines. The present study aimed to compare the efficacy of Levetiracetam, Sodium Valproate, and Propranolol in preventing migraine headaches in children.

Materials & Methods

In this clinical trial, children with migraine were randomly divided into three groups. Each group consisted of 13 children. Two groups were treated with Propranolol and Sodium Valproate, respectively. Another group (the case) was treated with Levetiracetam. The patients were assessed based on headache score, PedMIDAS, and headache frequency before and three months after the intervention. Finally, the data was analyzed using descriptive and analytical statistical methods.

Results

Levetiracetam significantly reduced the headache severity (P=0.026), frequency (P=0.024), and PedMIDAS score (P=0.001) in children with migraine. However, no significant difference was found between the three groups. The percentage of patients who experienced pain relief was detected as 69.24%, 92.31%, and 30.76% in the Propranolol, Sodium Valproate, and Levetiracetam groups, respectively.

Conclusion

This study concluded that Levetiracetam can be used as a migraine prophylaxis drug in children.

Comparing Pregabalin and Sodium Valproate in Pediatric Migraine Prophylaxis: A Randomized Clinical Trial

Objectives

Migraine is a common disorder in children, and its prophylaxis with minimal side effects is momentous. This study aimed to compare the efficacy of Pregabalin and Sodium Valproate in preventing migraine attacks.

Material & methods

Sixty-four children (aged 6-18) with migraines were recruited, as defined by Internation Headache Criteria (ICHD-III). They were randomly assigned to two groups: Sodium Valproate (n=32) and Pregabalin (n=32). The minimum dosage of drugs was prescribed in both groups. The patients were followed for four months. The parameters such as frequency, intensity, duration of migraine attacks, and the number of painkillers that the patients used monthly were recorded. The Spence Children's anxiety scale was also used to evaluate medications' effect on patients' anxiety levels.

Results

Two medications were equally effective in reducing the intensity and duration of attacks. Additionally, their effect on reducing the anxiety level of patients was equal. There was a significant difference between the effect of drugs on the frequency of migraine attacks at the end of the first and fourth months and the number of painkillers used at the end of the fourth month. The frequency of attacks was decreased by more than 50% in twenty-eight patients (90%) of Pregabalin recipients and twenty-one patients (84%) of Sodium Valproate recipients.

Conclusion

Considering the better effect of Pregabalin in the reduction of frequency of migraine attacks and pain-reducing medications consumption, Pregabalin could be a proper substitute for Sodium Valproate for prophylactic migraine treatment in children.

Imaging the brain and vascular reactions to headache treatments: a systematic review

BACKGROUND

Neuroimaging studies have made an important contribution to our understanding of headache pathophysiology. This systematic review aims to provide a comprehensive overview and critical appraisal of mechanisms of actions of headache treatments and potential biomarkers of treatment response disclosed by imaging studies.

MAIN BODY

We performed a systematic literature search on PubMed and Embase databases for imaging studies investigating central and vascular effects of pharmacological and non-pharmacological treatments used to abort and prevent headache attacks. Sixty-three studies were included in the final qualitative analysis. Of these, 54 investigated migraine patients, 4 cluster headache patients and 5 patients with medication overuse headache. Most studies used functional magnetic resonance imaging (MRI) (n = 33) or molecular imaging (n = 14). Eleven studies employed structural MRI and a few used arterial spin labeling (n = 3), magnetic resonance spectroscopy (n = 3) or magnetic resonance angiography (n = 2). Different imaging modalities were combined in eight studies. Despite of the variety of imaging approaches and results, some findings were consistent. This systematic review suggests that triptans may cross the blood-brain barrier to some extent, though perhaps not sufficiently to alter the intracranial cerebral blood flow. Acupuncture in migraine, neuromodulation in migraine and cluster headache patients, and medication withdrawal in patients with medication overuse headache could promote headache improvement by reverting headache-affected pain processing brain areas. Yet, there is currently no clear evidence for where each treatment acts, and no firm imaging predictors of efficacy. This is mainly due to a scarcity of studies and heterogeneous treatment schemes, study designs, subjects, and imaging techniques. In addition, most studies used small sample sizes and inadequate statistical approaches, which precludes generalizable conclusions.

CONCLUSION

Several aspects of headache treatments remain to be elucidated using imaging approaches, such as how pharmacological preventive therapies work, whether treatment-related brain changes may influence therapy effectiveness, and imaging biomarkers of clinical response. In the future, well-designed studies with homogeneous study populations, adequate sample sizes and statistical approaches are needed.

Antiseizure Medications for the Prophylaxis of Migraine during the Anti- CGRP Drugs Era

Migraine and epilepsy are fundamentally distinct disorders that can frequently coexist in the same patient. These two conditions significantly differ in diagnosis and therapy but share some widely- used preventive treatments. Antiseizure medications (ASMs) are the mainstay of therapy for epilepsy, and about thirty different ASMs are available to date. ASMs are widely prescribed for other neurological and non-neurological conditions, including migraine. However, only topiramate and valproic acid/valproate currently have an indication for migraine prophylaxis supported by high-quality evidence. Although without specifically approved indications and with a low level of evidence or recommendation, several other ASMs are used for migraine prophylaxis. Understanding ASM antimigraine mechanisms, including their ability to affect the pro-migraine calcitonin gene-related peptide (CGRP) signaling pathway and other pathways, may be instrumental in identifying the specific targets of their antimigraine efficacy and may increase awareness of the neurobiological differences between epilepsy and migraine. Several new ASMs are under clinical testing or have been approved for epilepsy in recent years, providing novel potential drugs for migraine prevention to enrich the treatment armamentarium and drugs that inhibit the CGRP pathway.

Health-Related Quality of Life in Migraine: EQ-5D-5L-Based Study in Routine Clinical Practice

BACKGROUND

Migraine leads to moderate to severe disabilities and disrupts family life, interpersonal relationships, and professional life, and is the second leading cause of disability worldwide. Many people with migraine suffer prolonged headaches and frequent migraine attacks, transition to having chronic migraine, and have the highest number of disability-adjusted life-years. The aim of this study is to measure the quality of life in migraineurs based on the EQ-5D-5L questionnaire.

METHODS

We assessed 100 consecutive patients diagnosed with migraine: 70 with episodic migraine and 30 with chronic migraine. Migraineurs were asked to complete the EQ-5D-5L. The control group (n = 100), matched for sex and age group, was created based on the results of the population norms study for the EQ-5D-5L in the general population of Poland.

RESULTS

Patients with migraine had worse HRQoL than the matched general population control group for all three primary endpoints of the EQ-5D-5L questionnaire: dimensions, EQ-5D-5L Index and EQ VAS.

CONCLUSIONS

Migraine is a disease that disrupts daily function, and as a lifelong disease, plays a role in every aspect of it. Proving a negative impact on many aspects helps to make decisions about treatment, especially in the context of the design and reimbursement of drugs.

Glutamate levels and perfusion in pons during migraine attacks: A 3T MRI study using proton spectroscopy and arterial spin labeling

Migraine is a complex disorder, involving peripheral and central brain structures, where mechanisms and site of attack initiation are an unresolved puzzle. While abnormal pontine neuronal activation during migraine attacks has been reported, exact implication of this finding is unknown. Evidence suggests an important role of glutamate in migraine, implying a possible association of pontine hyperactivity to increased glutamate levels. Migraine without aura patients were scanned during attacks after calcitonin gene-related peptide and sildenafil in a double-blind, randomized, double-dummy, cross-over design, on two separate study days, by proton magnetic resonance spectroscopy and pseudo-continuous arterial spin labeling at 3T. Headache characteristics were recorded until 24 h after drug administrations. Twenty-six patients were scanned during migraine, yielding a total of 41 attacks. Cerebral blood flow increased in dorsolateral pons, ipsilateral to pain side during attacks, compared to outside attacks (13.6%, p = 0.009). Glutamate levels in the same area remained unchanged during attacks (p = 0.873), while total creatine levels increased (3.5%, p = 0.041). In conclusion, dorsolateral pontine activation during migraine was not associated with higher glutamate levels. However, the concurrently increased total creatine levels may suggest an altered energy metabolism, which should be investigated in future studies to elucidate the role of pons in acute migraine.

Drug Treatment of Epilepsy Neuropsychiatric Comorbidities in Children

There is increasing recognition that epilepsy can be associated with a broad spectrum of comorbidities. While epileptic seizures are an essential element of epilepsy in children, there is a spectrum of neurological, mental health and cognitive disorders that add to the disease burden of childhood epilepsy resulting in a decreased quality of life. The most common comorbid conditions in childhood epilepsy include depression, anxiety, autism spectrum disorders, sleep disorders, attention deficits, cognitive impairment, and migraine. While epilepsy can result in comorbidities, many of the comorbidities of childhood have a bi-directional association, with the comorbid condition increasing risk for epilepsy and epilepsy increasing the risk for the comorbid condition. The bidirectional feature of epilepsy and the comorbidities suggest a common underlying pathological basis for both the seizures and comorbid condition. While recognition of the comorbid conditions of pediatric epilepsies is increasing, there has been a lag in the development of effective therapies partly out of concern that drugs used to treat the comorbid conditions could increase seizure susceptibility. There is now some evidence that most drugs used for comorbid conditions are safe and do not lower seizure threshold. Unfortunately, the evidence showing drugs are effective in treating many of the childhood comorbidities of epilepsy is quite limited. There is a great need for randomized, placebo-controlled drug trials for efficacy and safety in the treatment of comorbidities of childhood epilepsy.

The fifth cranial nerve in headaches

The fifth cranial nerve is the common denominator for many headaches and facial pain pathologies currently known. Projecting from the trigeminal ganglion, in a bipolar manner, it connects to the brainstem and supplies various parts of the head and face with sensory innervation. In this review, we describe the neuroanatomical structures and pathways implicated in the sensation of the trigeminal system. Furthermore, we present the current understanding of several primary headaches, painful neuropathies and their pharmacological treatments. We hope that this overview can elucidate the complex field of headache pathologies, and their link to the trigeminal nerve, to a broader field of young scientists.

Cochrane systematic review and meta-analysis of botulinum toxin for the prevention of migraine

OBJECTIVES

To assess the effects of botulinum toxin for prevention of migraine in adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CENTRAL, MEDLINE, Embase and trial registries.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) of botulinum toxin compared with placebo, active treatment or clinically relevant different dose for adults with chronic or episodic migraine, with or without the additional diagnosis of medication overuse headache.

DATA EXTRACTION AND SYNTHESIS

Cochrane methods were used to review double-blind RCTs. Twelve week post-treatment time-point data was analysed.

RESULTS

Twenty-eight trials (n=4190) were included. Trial quality was mixed. Botulinum toxin treatment resulted in reduced frequency of -2.0 migraine days/month (95% CI -2.8 to -1.1, n=1384) in chronic migraineurs compared with placebo. An improvement was seen in migraine severity, measured on a numerical rating scale 0 to 10 with 10 being maximal pain, of -2.70 cm (95% CI -3.31 to -2.09, n=75) and -4.9 cm (95% CI -6.56 to -3.24, n=32) for chronic and episodic migraine respectively. Botulinum toxin had a relative risk of treatment related adverse events twice that of placebo, but a reduced risk compared with active comparators (relative risk 0.76, 95% CI 0.59 to 0.98) and a low withdrawal rate (3%). Although individual trials reported non-inferiority to oral treatments, insufficient data were available for meta-analysis of effectiveness outcomes.

CONCLUSIONS

In chronic migraine, botulinum toxin reduces migraine frequency by 2 days/month and has a favourable safety profile. Inclusion of medication overuse headache does not preclude its effectiveness. Evidence to support or refute efficacy in episodic migraine was not identified.

Psychological therapies for the prevention of migraine in adults

BACKGROUND

Migraine is a common neurological problem associated with the highest burden amongst neurological conditions in terms of years lived with disability. Medications can be used as prophylaxis or rescue medicines, but are costly and not always effective. A range of psychological interventions have been developed to manage migraine.

OBJECTIVES

The objective was to evaluate the efficacy and adverse events of psychological therapies for the prevention of migraine in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL from their inception until July 2018, and trials registries in the UK, USA, Australia and New Zealand for randomised controlled trials of any psychological intervention for adults with migraine.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of a psychological therapy for people with chronic or episodic migraine, with or without aura. Interventions could be compared to another active treatment (psychological or medical), an attention-placebo (e.g. supportive counselling) or other placebo, routine care, or waiting-list control. We excluded studies where fewer than 15 participants completed each arm.

DATA COLLECTION AND ANALYSIS

We extracted study characteristics and outcome data at post-treatment and the longest available follow-up. We analysed intervention versus control comparisons for the primary outcome of migraine frequency. We measured migraine frequency using days with migraines or number of migraine attacks measured in the four weeks after treatment. In addition, we analysed the following secondary outcomes: responder rate (the proportion of participants with a 50% reduction in migraine frequency between the four weeks prior to and the four weeks after treatment); migraine intensity; migraine duration; migraine medication usage; mood; quality of life; migraine-related disability; and proportion of participants reporting adverse events during the treatment. We included these variables, where available, at follow-up, the timing of which varied between the studies. We used the GRADE approach to judge the quality of the evidence.

MAIN RESULTS

We found 21 RCTs including 2482 participants with migraine, and we extracted meta-analytic data from 14 of these studies. The majority of studies recruited participants through advertisements, included participants with migraine according to the International Classification of Headache Disorders (ICHD) criteria and those with and without aura. Most intervention arms were a form of behavioural or cognitive-behavioural therapy. The majority of comparator arms were no treatment, routine care or waiting list. Interventions varied from one 20-minute session to 14 hours of intervention. No study had unequivocally low risk of bias; all had at least one domain at high risk of bias, and 20 had two to five domains at high risk. Reporting of randomisation procedures and allocation concealment were at high or unclear risk of bias. We downgraded the quality of evidence for outcomes to very low, due to very serious limitations in study quality and imprecision. Reporting in trials was poor; we found no preregistrations stipulating the outcomes, or demonstrating equivalent expectations between groups. Few studies reported our outcomes of interest, most only reported outcomes post treatment; follow-up data were sparse.Post-treatment effectsWe found no evidence of an effect of psychological interventions for migraine frequency in number of migraines or days with migraine (standardised mean difference (SMD) -0.02, 95% confidence interval (CI) -0.17 to 0.13; 4 studies, 681 participants; very low-quality evidence).The responder rate (proportion of participants with migraine frequency reduction of more than 50%) was greater for those who received a psychological intervention compared to control: 101/186 participants (54%) with psychological therapy; 37/152 participants (24%) with control (risk ratio (RR) 2.21, 95% CI 1.63 to 2.98; 4 studies, 338 participants; very low-quality evidence). We found no effect of psychological therapies on migraine intensity (SMD -0.13, 95% CI -0.28 to 0.02; 4 studies, 685 participants). There were no data for migraine duration (hours of migraine per day). There was no effect on migraine medication usage (SMD -0.06, 95% CI -0.35 to 0.24; 2 studies, 483 participants), mood (mean difference (MD) 0.08, 95% CI -0.33 to 0.49; 4 studies, 432 participants), quality of life (SMD -0.02, 95% CI -0.30 to 0.26; 4 studies, 565 participants), or migraine-related disability (SMD -0.67, 95% CI -1.34 to 0.00; 6 studies, 952 participants). The proportion of participants reporting adverse events did not differ between those receiving psychological treatment (9/107; 8%) and control (30/101; 30%) (RR 0.16, 95% CI 0.00 to 7.85; 2 studies, 208 participants). Only two studies reported adverse events and so we were unable to draw any conclusions.We rated evidence from all studies as very low quality.Follow-upOnly four studies reported any follow-up data. Follow-ups ranged from four months following intervention to 11 months following intervention. There was no evidence of an effect on any outcomes at follow-up (very low-quality evidence).

AUTHORS' CONCLUSIONS

This review identified 21 studies of psychological interventions for the management of migraine. We did not find evidence that psychological interventions affected migraine frequency, a result based on four studies of primarily brief treatments. Those who received psychological interventions were twice as likely to be classified as responders in the short term, but this was based on very low-quality evidence and there was no evidence of an effect of psychological intervention compared to control at follow-up. There was no evidence of an effect of psychological interventions on medication usage, mood, migraine-related disability or quality of life. There was no evidence of an effect of psychological interventions on migraine frequency in the short-term or long-term. In terms of adverse events, we were unable to draw conclusions as there was insufficient evidence. High and unclear risk of bias in study design and reporting, small numbers of participants, performance and detection bias meant that we rated all evidence as very low quality. Therefore, we conclude that there is an absence of high-quality evidence to determine whether psychological interventions are effective in managing migraine in adults and we are uncertain whether there is any difference between psychological therapies and controls.

Current Status of Antiepileptic Drugs as Preventive Migraine Therapy

BACKGROUND

Antiepileptic drugs (AEDs) are an important class of agents used in the treatment of migraine, a neurological disorder that imparts significant socioeconomic burden. It is important for neurologists to understand the rationale for AEDs in migraine-preventive treatment, as well as each agent's efficacy and tolerability profile, in order to best determine clinical care.

PURPOSE OF THIS REVIEW

This article specifically provides the following: (1) a review of the mechanism of action, efficacy, and tolerability of topiramate and divalproex sodium/sodium valproate, the most widely used AEDs for migraine prevention, (2) a discussion on emerging evidence regarding the efficacy of zonisamide and levetiracetam, and (3) comments on gabapentin, pregabalin, carbamazepine, oxcarbazepine, and lamotrigine, AEDs which have insufficient evidence for use in migraine prevention.

RECENT FINDINGS

The potential role for new extended-release formulations of topiramate in migraine prevention is discussed. There is substantial evidence supporting the use of AEDs in migraine prevention. Specific agents should be chosen based on their efficacy and tolerability profiles. Further studies are needed to determine the efficacy of the newer AEDs, zonisamide and levetiracetam, in migraine prevention and to clarify the role of gabapentinoids in headache management.

Botulinum toxins for the prevention of migraine in adults

BACKGROUND

Migraine occurs in around 15% of adults and is ranked as the seventh most disabling disease amongst all diseases globally. Despite the available treatments many people suffer prolonged and frequent attacks which have a major impact on their quality of life. Chronic migraine is defined as 15 or more days of headache per month, at least eight of those days being migraine. People with episodic migraine have fewer than 15 headache days per month. Botulinum toxin type A has been licensed in some countries for chronic migraine treatment, due to the results of just two trials.

OBJECTIVES

To assess the effects of botulinum toxins versus placebo or active treatment for the prevention or reduction in frequency of chronic or episodic migraine in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE & MEDLINE in Process, Embase, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry (to December 2017). We examined reference lists and carried out citation searches on key publications. We sent correspondence to major manufacturers of botulinum toxin.

SELECTION CRITERIA

Randomised, double-blind, controlled trials of botulinum toxin (any sero-type) injections into the head and neck for prophylaxis of chronic or episodic migraine in adults. Eligible comparators were placebo, alternative prophylactic agent or different dose of botulinum toxin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. For continuous outcomes we used mean change data when available. For dichotomous data we calculated risk ratios (RRs). We used data from the 12-week post-treatment follow-up time point. We assessed the evidence using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

Description of trialsWe found 90 articles describing 28 trials (4190 participants), which were eligible for inclusion. The longest treatment duration was three rounds of injections with three months between treatments, so we could not analyse long-term effects. For the primary analyses, we pooled data from both chronic and episodic participant populations. Where possible, we also separated data into chronic migraine, episodic migraine and 'mixed group' classification subgroups. Most trials (21 out of 28) were small (fewer than 50 participants per trial arm). The risk of bias for included trials was low or unclear across most domains, with some trials reporting a high risk of bias for incomplete outcome data and selective outcome reporting.Botulinum toxin versus placeboTwenty-three trials compared botulinum toxin with placebo. Botulinum toxin may reduce the number of migraine days per month in the chronic migraine population by 3.1 days (95% confidence interval (CI) -4.7 to -1.4, 4 trials, 1497 participants, low-quality evidence). This was reduced to -2 days (95% CI -2.8 to -1.1, 2 trials, 1384 participants; moderate-quality evidence) when we removed small trials.A single trial of people with episodic migraine (N = 418) showed no difference between groups for this outcome measure (P = 0.49).In the chronic migraine population, botulinum toxin reduces the number of headache days per month by 1.9 days (95% CI -2.7 to -1.0, 2 trials, 1384 participants, high-quality evidence). We did not find evidence of a difference in the number of migraine attacks for both chronic and episodic migraine participants (6 trials, N = 2004, P = 0.30, low-quality evidence). For the population of both chronic and episodic migraine participants a reduction in severity of migraine rated during clinical visits, on a 10 cm visual analogue scale (VAS) of 3.3 cm (95% CI -4.2 to -2.5, very low-quality evidence) in favour of botulinum toxin treatment came from four small trials (N = 209); better reporting of this outcome measure from the additional eight trials that recorded it may have improved our confidence in the pooled estimate. Global assessment and quality-of-life measures were poorly reported and it was not possible to carry out statistical analysis of these outcome measures. Analysis of adverse events showed an increase in the risk ratio with treatment with botulinum toxin over placebo 30% (RR 1.28, 95% CI 1.12 to 1.47, moderate-quality evidence). For every 100 participants 60 experienced an adverse event in the botulinum toxin group compared with 47 in the placebo group.Botulinum toxin versus other prophylactic agentThree trials studied comparisons with alternative oral prophylactic medications. Meta-analyses were not possible for number of migraine days, number of headache days or number of migraine attacks due to insufficient data, but individually trials reported no differences between groups for a variety of efficacy measures in the population of both chronic and episodic migraine participants. The global impression of disease measured using Migraine Disability Assessment (MIDAS) scores were reported from two trials that showed no difference between groups. Compared with oral treatments, botulinum toxin showed no between-group difference in the risk of adverse events (2 trials, N = 114, very low-quality evidence). The relative risk reduction (RRR) for withdrawing from botulinum toxin due to adverse events compared with the alternative prophylactic agent was 72% (P = 0.02, 2 trials, N = 119).Dosing trialsThere were insufficient data available for the comparison of different doses.Quality of the evidenceThe quality of the evidence assessed using GRADE methods was varied but mostly very low; the quality of the evidence for the placebo and active control comparisons was low and very low, respectively for the primary outcome measure. Small trial size, high risk of bias and unexplained heterogeneity were common reasons for downgrading the quality of the evidence.

AUTHORS' CONCLUSIONS

In chronic migraine, botulinum toxin type A may reduce the number of migraine days per month by 2 days compared with placebo treatment. Non-serious adverse events were probably experienced by 60/100 participants in the treated group compared with 47/100 in the placebo group. For people with episodic migraine, we remain uncertain whether or not this treatment is effective because the quality of this limited evidence is very low. Better reporting of outcome measures in published trials would provide a more complete evidence base on which to draw conclusions.

Current Status of the New Antiepileptic Drugs in Chronic Pain

Antiepileptic drugs (AEDs) are extensively used worldwide to treat a wide range of disorders other than epilepsy, such as neuropathic pain, migraine, and bipolar disorder. Due to this situation more than 20 new third-generation AEDs have been introduced in the market recently. The future design of new AEDs must also have potential to help in the non-epileptic disorders. The wide acceptance of second generation AEDs for the management of various non-epileptic disorders has caused the emergence of generics in the market. The wide use of approved AEDs outside epilepsy is based on both economic and scientific reasons. Bipolar disorders, migraine prophylaxis, fibromyalgia, and neuropathic pain represent the most attractive indication expansion opportunities for anticonvulsant developers, providing blockbuster revenues. Strong growth in non-epilepsy conditions will see Pfizer's Lyrica become the market leading brand by 2018. In this review, we mainly focus on the current status of new AEDs in the treatment of chronic pain and migraine prophylaxis. AEDs have a strong analgesic potential and this is demonstrated by the wide use of carbamazepine in trigeminal neuralgia and sodium valproate in migraine prophylaxis. At present, data on the new AEDs for non-epileptic conditions are inconclusive. Not all AEDs are effective in the management of neuropathic pain and migraine. Only those AEDs whose mechanisms of action are match with pathophysiology of the disease, have potential to show efficacy in non-epileptic disorder. For this better understanding of the pathophysiology of the disease and mechanisms of action of new AEDs are essential requirement before initiating pre-clinical and clinical trials. Many new AEDs show good results in the animal model and open-label studies but fail to provide strong evidence at randomized, placebo-controlled trials. The final decision regarding the clinical efficacy of the particular AEDs in a specific non-epileptic disorder should be withdrawal from randomized placebo trials rather than open-label studies; otherwise this may lead to off-label uses of drug. The purpose of the present review is to relate the various mechanisms of action of new AEDs to pathophysiological mechanisms and clinical efficacy in neuropathic pain and migraine.

Antiepileptic use for epilepsy and nonepilepsy disorders: A population-based study (1998-2013)

OBJECTIVE

To examine the trends in antiepileptic drug (AED) use among individuals living in Manitoba with and without a history of epilepsy.

METHODS

Using data obtained from administrative health databases in Manitoba, we assessed the quarterly prevalence of AED use between 1998 and 2013 among individuals with and without a history of epilepsy using cross-sectional time series analysis.

RESULTS

Over the study period, the number of individuals prescribed AEDs increased more than 3-fold, from 8,883 to 27,246. The prevalence of AED use among patients with epilepsy increased by 3%, from 789.6 per 1,000 in 1998/1999 to 813.9 per 1,000 in 2012/2013 (p < 0.001 after 2006). In contrast, we observed a 210% increase in AED use among patients without epilepsy from 6.8 to 21.1 per 1,000 over the same period (p < 0.001). We observed a 55-fold rise in gabapentin use among patients without a seizure disorder (from 0.2 to 11.1 per 1,000; p < 0.001), while gabapentin use among those with epilepsy increased only 2-fold, from 21.6 to 41.3 per 1,000 (p < 0.001).

CONCLUSIONS

There has been a marked increase in the prevalence of AED users over the last 15 years, with a large shift towards the use of newer antiepileptic agents (primarily gabapentin) among those without epilepsy. Further research on the effect of these trends on health and economic outcomes will be of interest for clinicians and policymakers.

Acetazolamide in vestibular migraine prophylaxis: a retrospective study

The aim of this study is to check the efficacy of acetazolamide in the prophylaxis of vestibular migraine (VM). Treatment options in VM are mainly based on migraine guidelines. We tried to assess the efficacy of acetazolamide in these patients depending on clinical similarities with episodic ataxia type 2 and familial hemiplegic migraine responding to the drug. This is a retrospective cohort study. Among 50 patients with VM and prescribed acetazolamide 500 mg/day, 39 patients were studied as five had been lost on follow-up and six had stopped taking the drug due to side effects. Vertigo and headache frequency determined by number of attacks per month, and the severity determined by visual analog scales measured in centimeters from 0 to 10 were collected from the records. Initial reported figures for frequency and severity were compared with the results gathered after 3 months of treatment. The results were compared. Acetazolamide was effective in reducing both the frequency and severity of vertigo and headache attacks and this effect was more prominent for vertigo frequency and severity.

Comparison of Levetiracetam and sodium Valproate in migraine prophylaxis: A randomized placebo-controlled study

Background:

Migraine is a chronic and disabling disorder. Treatment of migraine often comprises of symptomatic (abortive) and preventive (prophylactic) treatment. The current drugs used in migraine prophylaxis include antidepressant drugs (Serotonin Reuptake Inhibitors, Tricyclic antidepressants), and anti-epileptic drugs (valproate, gabapentin, etc).

Objective:

The objective of our study was to assess the efficacy and tolerability of levetiracetam in adult migraine prophylaxis, compared to valproate and placebo.

Materials and Methods:

We conducted a prospective, randomized, placebo-controlled study. A total of 85 patients were randomized to receive levetiracetam 500 mg/d (n = 27), valproate 500 mg/d (n = 32) or placebo (n = 26). The patients were evaluated for treatment efficacy after 6 months. Efficacy was assessed as a more than 50% decrease in headache frequency.

Results:

In levetiracetam group, 17 (63.0%) patients experienced a more than 50% decrease in headache frequency, while this efficacy number was 21 (65.6%) for valproate group and 4 (15.4%) for placebo group. The difference was not statistically significant between levetiracetam and valproate, while it was significant when comparing either levetiracetam or valproate to placebo.

Conclusion:

Compared to placebo, levetiracetam offers improvement in headache frequency in patients with migraine. The efficacy of levetiracetam in migraine prophylaxis is comparable to currently used drugs such as valproate.

Migraine prophylaxis, ischemic depolarizations, and stroke outcomes in mice

BACKGROUND AND PURPOSE

Migraine with aura is an established stroke risk factor, and excitatory mechanisms such as spreading depression (SD) are implicated in the pathogenesis of both migraine and stroke. Spontaneous SD waves originate within the peri-infarct tissue and exacerbate the metabolic mismatch during focal cerebral ischemia. Genetically enhanced SD susceptibility facilitates anoxic depolarizations and peri-infarct SDs and accelerates infarct growth, suggesting that susceptibility to SD is a critical determinant of vulnerability to ischemic injury. Because chronic treatment with migraine prophylactic drugs suppresses SD susceptibility, we tested whether migraine prophylaxis can also suppress ischemic depolarizations and improve stroke outcome.

METHODS

We measured the cortical susceptibility to SD and ischemic depolarizations, and determined tissue and neurological outcomes after middle cerebral artery occlusion in wild-type and familial hemiplegic migraine type 1 knock-in mice treated with vehicle, topiramate or lamotrigine daily for 7 weeks or as a single dose shortly before testing.

RESULTS

Chronic treatment with topiramate or lamotrigine reduced the susceptibility to KCl-induced or electric stimulation-induced SDs as well as ischemic depolarizations in both wild-type and familial hemiplegic migraine type 1 mutant mice. Consequently, both tissue and neurological outcomes were improved. Notably, treatment with a single dose of either drug was ineffective.

CONCLUSIONS

These data underscore the importance of hyperexcitability as a mechanism for increased stroke risk in migraineurs, and suggest that migraine prophylaxis may not only prevent migraine attacks but also protect migraineurs against ischemic injury.

Topiramate for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of topiramate for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of topiramate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between topiramate and comparator (placebo, active control, or topiramate in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and, in select cases, risk ratios (RRs); we also calculated numbers needed to treat (NNTs). We calculated MDs for selected quality of life instruments. Finally, we summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Twenty papers describing 17 unique trials met the inclusion criteria. Analysis of data from nine trials (1737 participants) showed that topiramate reduced headache frequency by about 1.2 attacks per 28 days as compared to placebo (MD -1.20; 95% confidence interval (CI) -1.59 to -0.80). Data from nine trials (1190 participants) show that topiramate approximately doubled the proportion of responders relative to placebo (RR 2.02; 95% CI 1.57 to 2.60; NNT 4; 95% CI 3 to 6). Separate analysis of different topiramate doses produced similar MDs versus placebo at 50 mg (-0.95; 95% CI -1.95 to 0.04; three studies; 520 participants), 100 mg (-1.15; 95% CI -1.58 to -0.71; six studies; 1620 participants), and 200 mg (-0.94; 95% CI -1.53 to -0.36; five studies; 804 participants). All three doses significantly increased the proportion of responders relative to placebo; ORs were as follows: for 50 mg, 2.35 (95% CI 1.60 to 3.44; three studies; 519 participants); for 100 mg, 3.49 (95% CI 2.23 to 5.45; five studies; 852 participants); and for 200 mg, 2.49 (95% CI 1.61 to 3.87; six studies; 1025 participants). All three doses also significantly improved three or more domains of quality of life as compared to placebo. Meta-analysis of the three studies that included more than one dose of topiramate suggests that 200 mg is no more effective than 100 mg. With regard to mean headache frequency and/or responder rate, seven trials using active comparators found (a) no significant difference between topiramate and amitriptyline (one study, 330 participants); (b) no significant difference between topiramate and flunarizine (one study, 83 participants); (c) no significant difference between topiramate and propranolol (two studies, 342 participants); (d) no significant difference between topiramate and relaxation (one study, 61 participants); but (e) a slight significant advantage of topiramate over valproate (two studies, 120 participants). Relaxation improved migraine-specific quality of life significantly more than topiramate. In trials of topiramate against placebo, seven adverse events (AEs) were reported by at least three studies. These were usually mild and of a non-serious nature. Except for taste disturbance and weight loss, there were no significant differences in the frequency of AEs in general, or of the seven specific AEs, between placebo and topiramate 50 mg. AEs in general and all of the specific AEs except nausea were significantly more common on topiramate 100 mg than on placebo, with NNHs varying from 3 to 25, and the RDs versus placebo were even higher for topiramate 200 mg, with NNHs varying from 2 to 17.

AUTHORS' CONCLUSIONS

Meta-analysis demonstrates that topiramate in a 100 mg/day dosage is effective in reducing headache frequency and reasonably well-tolerated in adult patients with episodic migraine. This provides good evidence to support its use in routine clinical management. More studies designed specifically to compare the efficacy or safety of topiramate versus other interventions with proven efficacy in the prophylaxis of migraine are needed.

Valproate (valproic acid or sodium valproate or a combination of the two) for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of valproate (valproic acid or sodium valproate or a combination of the two) for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of valproate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between valproate and comparator (placebo, active control, or valproate in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and, in select cases, risk ratios (RRs); we also calculated numbers needed to treat (NNTs). We calculated MDs for Migraine Disability Assessment (MIDAS) scores. We also summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Ten papers describing 10 unique trials met the inclusion criteria. Analysis of data from two trials (63 participants) showed that sodium valproate reduced headache frequency by approximately four headaches per 28 days as compared to placebo (MD -4.31; 95% confidence interval (CI) -8.32 to -0.30). Data from four trials (542 participants) showed that divalproex sodium (a stable combination of sodium valproate and valproic acid in a 1:1 molar ratio) more than doubled the proportion of responders relative to placebo (RR 2.18; 95% CI 1.28 to 3.72; NNT 4; 95% CI 2 to 11). One study of sodium valproate (34 participants) versus placebo supported the latter findings (RR for responders 2.83; 95% CI 1.27 to 6.31; NNT 3; 95% CI 2 to 9). There was no significant difference in the proportion of responders between sodium valproate versus flunarizine (one trial, 41 participants) or between divalproex sodium versus propranolol (one trial, 32 participants). Pooled analysis of post-treatment mean headache frequencies in two trials (88 participants) demonstrates a slight but significant advantage for topiramate 50 mg over valproate 400 mg (MD -0.90; 95% CI -1.58 to -0.22). For placebo-controlled trials of sodium valproate and divalproex sodium, NNHs for clinically important adverse events ranged from 7 to 14.

AUTHORS' CONCLUSIONS

Valproate is effective in reducing headache frequency and is reasonably well tolerated in adult patients with episodic migraine.

Gabapentin or pregabalin for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of gabapentin/gabapentin enacarbil or pregabalin for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of gabapentin/gabapentin enacarbil or pregabalin taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between gabapentin and comparator (placebo, active control, or gabapentin in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and numbers needed to treat (NNTs). We also summarised data on adverse events from all single dosage studies and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Five trials on gabapentin and one trial on its prodrug gabapentin enacarbil met the inclusion criteria; no reports on pregabalin were identified. In total, data from 1009 patients were considered. One trial each of gabapentin 900 mg (53 patients), and gabapentin titrated to 1200 mg (63 patients) and 1800 mg (122 patients) failed to show a statistically significant reduction in headache frequency in the active treatment group as compared to the placebo group, whereas one trial of gabapentin titrated to 1800 to 2400 mg (113 patients) demonstrated a small but statistically significant superiority of active treatment for this outcome (MD -0.80; 95% confidence interval (CI) -1.55 to -0.05). The pooled results of these four studies (MD -0.44; 95% CI -1.43 to 0.56; 351 patients) do not demonstrate a significant difference between gabapentin and placebo. One trial of gabapentin titrated to 1800 mg (122 patients) failed to demonstrate a significant difference between active treatment and placebo in the proportion of responders (OR 0.97; 95% CI 0.45 to 2.11), whereas one trial of gabapentin titrated to 1800 to 2400 mg (113 patients) demonstrated a small but statistically significant superiority of active treatment for this outcome (OR 2.79; 95% CI 1.09 to 7.17). The pooled results of these two studies (OR 1.59; 95% CI 0.57 to 4.46; 235 patients) do not demonstrate a significant difference between gabapentin and placebo. Comparisons from one study (135 patients) suggest that gabapentin 2000 mg is no more effective than gabapentin 1200 mg. One trial of gabapentin enacarbil (523 participants) failed to demonstrate a significant difference versus placebo or between doses for gabapentin enacarbil titrated to between 1200 mg and 3000 mg with regard to proportion of responders; there was also no evidence of a dose-response trend. Adverse events, most notably dizziness and somnolence, were common with gabapentin.

AUTHORS' CONCLUSIONS

The pooled evidence derived from trials of gabapentin suggests that it is not efficacious for the prophylaxis of episodic migraine in adults. Since adverse events were common among the gabapentin-treated patients, it is advocated that gabapentin should not be used in routine clinical practice. Gabapentin enacarbil is not efficacious for the prophylaxis of episodic migraine in adults. There is no published evidence from controlled trials of pregabalin for the prophylaxis of episodic migraine in adults.

Antiepileptics other than gabapentin, pregabalin, topiramate, and valproate for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of antiepileptic drugs other than gabapentin, pregabalin, topiramate, and valproate (which are the subjects of separate Cochrane reviews) for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of antiepileptic drugs other than gabapentin, pregabalin, topiramate, and valproate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between antiepileptic drugs and comparators (placebo, active control, or same drug in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and numbers needed to treat (NNTs). We also summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Eleven papers describing 10 unique trials met the inclusion criteria. The 10 trials reported results for nine antiepileptic drugs other than gabapentin, pregabalin, topiramate, and valproate. Six of the eight drugs investigated in placebo-controlled trials were not better than placebo in reducing headache frequency per 28-day period during treatment (clonazepam, lamotrigine, oxcarbazepine, and vigabatrin) and/or in the proportion of responders (acetazolamide, carisbamate, lamotrigine, oxcarbazepine). One prospective, randomised, double-blind, single cross-over trial of 48 patients demonstrated a significant superiority of carbamazepine over placebo in the proportion of responders (OR 11.77; 95% confidence interval (CI) 3.92 to 35.32). The NNT was 2 (95% CI 2 to 3). In a small prospective, randomised, double-blind, parallel-group trial, levetiracetam 1000 mg was significantly superior to placebo in reducing headache frequency per 28-day period during treatment (MD -2.40; 95% CI -4.52 to -0.28; 26 patients), as well as in the proportion of responders (OR 26.07; 95% CI 1.30 to 521.91; 26 patients). The NNT was 2 (95% CI 1 to 4). The same trial examined levetiracetam 1000 mg versus topiramate 100 mg and found a small but significant difference favouring topiramate in headache frequency per 28-day period during treatment (MD 1.40; 95% CI 0.14 to 2.66; 28 patients). There was no significant difference between levetiracetam and topiramate in the proportion of responders (OR 0.71; 95% CI 0.16 to 3.23; 28 patients). Finally, one trial with 75 participants examined zonisamide versus topiramate (200 and 100 mg, respectively) and found no significant difference between them in reduction of headache frequency from baseline during the third month of treatment. Adverse events for active treatment versus placebo were available for all investigated drugs except levetiracetam, vigabatrin, and zonisamide. A high prevalence of adverse events was noted for carbamazepine, with a NNH of only 2 (95% CI 2 to 4).

AUTHORS' CONCLUSIONS

Available evidence does not allow robust conclusions regarding the efficacy of antiepileptic drugs other than gabapentin, pregabalin, topiramate, and valproate in the prophylaxis of episodic migraine among adults. Acetazolamide, carisbamate, clonazepam, lamotrigine, oxcarbazepine, and vigabatrin were not more effective than placebo in reducing headache frequency. In one trial each, carbamazepine and levetiracetam were significantly superior to placebo in reducing headache frequency, and there was no significant difference in proportion of responders between zonisamide and active comparator. These three positive studies suffer from considerable methodological limitations.