The evolution of chronic migraine: classification and nomenclature

Chronic migraine and medication overuse

Though clearly described as far back as the 17th century, chronic migraine has defied precise categorization and has continued to develop as an important diagnostic concept with significant societal impact. Worldwide prevalence is estimated to be between 1% and 3%, and these patients form a dynamic group cycling between chronic and episodic migraine. Theories of pathogenesis are developing supported by recent imaging and other findings. Of the many determinants of progression to chronic migraine, overuse of acute abortive headache medications may be one of the most important modifiable factors. Treatment strategies, in addition to educational measures, have included various preventive migraine medications such as topiramate, valproate, and onabotulinumtoxinA. CGRP monoclonal antibodies are efficacious for the management of chronic migraine both with and without medication overuse.

Episodic Migraine Comorbidities: Avoiding Pitfalls and Taking Therapeutic Opportunities

Migraine is a common neurologic disorder. This article will discuss a few factors that influence migraine (mostly episodic) and its treatment, such as sleep, obstructive sleep apnea (OSA), obesity, and affective disorders, as well as autoimmune diseases. Practitioners must be aware of these coexisting conditions (comorbidities) as they affect treatment. It is noted in literature that both the quantity (too much or too few hours) and the quality (OSA related) of sleep may worsen migraine frequency. An associated risk factor for OSA, obesity also increases migraine frequency in episodic migraine cases. A bidirectional relationship with migraine along with depression and anxiety is debated in the literature. Retrospective cohort studies are undecided and lack statistical significance, but prospective studies do show promising results on treatment of anxiety and depression as a means of improving migraine control. Finally, we address the topic of autoimmune diseases and migraine. While few studies exist at this time, there are cohort study groups looking into the association between rheumatoid arthritis, hypothyroidism, and antiphospholipid antibody. There is also evidence for the link between migraine and vascular diseases, including coronary and cerebral diseases. We suggest that these comorbid conditions be taken into account and individualized for each patient along with their pharmaceutical regimen. Physicians should seek a multifactorial treatment plan including diet, exercise, and healthy living to reduce migraine frequency.

Migraine Progression: A Systematic Review

BACKGROUND

Migraine is a common and often debilitating neurological disease. It can be divided into episodic and chronic subforms based on the number of monthly headache days. Because only a subset of individuals with episodic migraine (EM) progress to chronic migraine (CM) over any given time period, understanding the factors that predict the new onset of CM or "migraine progression" may provide insights into the mechanisms, pathophysiology, prevention, and treatment of CM. In this review, we identify and summarize studies that report risk factors associated with the new onset of CM or related chronic headache diagnoses, group these risk factors and report the strength of evidence for the identified risk factors.

OBJECTIVE

To conduct a systematic review of studies that identify risk factors for the new onset of CM or related chronic headache diagnoses such as transformed migraine (TM) and chronic daily headache (CDH).

METHODS

Herein we summarize the findings of studies of risk factors associated with the new onset of CM/TM, CDH, or related diagnoses from the English language literature published before March 2018. The PubMed database was searched for relevant studies. Longitudinal studies with follow-up data and case-control studies were included in this qualitative synthesis. We report methodology, analytic criteria, and results for each manuscript and for the parent study. Next, we review the strength of evidence for each of the identified risk factors using a modified version of AB Hill's criteria for causation and rank evidence as fair, moderate, or strong. We categorized risk factors as nonmodifiable, modifiable and based on putative mechanisms. We further categorized risk factors into sociodemographics, lifestyle factors and habits, headache features, comorbid and concomitant diseases and conditions and pharmacologic treatment-related. Finally, we review theories of the pathophysiology underlying the development of new onset chronic migraine or increasing attack frequency.

RESULTS

The PubMed search yielded 1870 records after duplicates were removed. Nine additional records were identified through expert consultation and other methods (eg, citations found as references in manuscripts identified in the literature review and through communication with the authors of manuscripts included in the review). The 1879 manuscripts were screened against the inclusion and exclusion criteria and 109 were found to be potentially eligible. Of 109 full-text articles, 17 studies were identified as meeting the prespecified criteria based on the consensus of all authors. Of the 17 full texts, 13 were longitudinal cohort studies and 4 were case-controlled studies. We found strength of evidence ranging from fair to strong for the identified risk factors. The strongest data were found for increased headache day frequency, depression, and medication overuse/high-frequency use. Risk factors for new onset CM and CDH in children and adolescents were similar to those identified in adults.

CONCLUSIONS

A range of risk factors for the new onset of CM/TM, CDH, or related chronic headache diseases were identified with the strongest data supporting increased headache day frequency, acute medication overuse/high-frequency use and depression, which are potentially modifiable risk factors. Modifiable risk factors may provide targets for intervention. The lack of strong evidence or any evidence does not imply that there is not a relationship between a particular risk factor and new onset CM or related disease; but may indicate little or no research or that research did not have sufficient methodological rigor. In addition, it is likely that additional risk factors exist which have not yet been identified. Putative factors include pro-inflammatory states and pro-thrombotic states. Development of central sensitization and increased activation of the trigeminal nociceptive pathways may be drivers of the new onset of CM or CDH. Future research may include the systematic testing of interventions targeting modifiable risk factors to determine if progression can be prevented as well as continued exploration of the benefits of treating these risk factors among people with CM in an effort to increase rates of remission. Future work should also consider the natural fluctuations in headache day frequency and examine progression in terms of continuous definitions rather than or in addition to a dichotomous boundary.

Sleep in Patients with Chronic Migraine

PURPOSE OF REVIEW

The biological and pathophysiological interaction between sleep and chronic migraine (CM) remains to be fully elucidated. In this article, we provide a narrative review of the literature on sleep disturbance and CM, highlighting recent advances in sleep research and insights into mechanisms that could mediate a role of sleep disturbances in migraine chronification. We discuss the potential for cognitive-behavioral insomnia therapy (CBTi) as an intervention for CM with comorbid insomnia. Finally, we propose a model of the mechanisms underlying the interactions among sleep physiology, maladaptive migraine-coping behaviors, and coexisting factors which contribute to sleep disturbances in CM based on conceptual models used in sleep research.

RECENT FINDINGS

Insomnia is the most common sleep complaint among patients with CM. CM patients experience more frequent and severe insomnia symptoms than patients with episodic migraine (EM). It has been suggested that sleep disturbances may predispose individuals to migraine attacks, which may affect the pain-processing trigeminovascular system and thus play a role in migraine progression. Encouraging but limited evidence suggests that management of insomnia via behavioral sleep therapy may reverse CM to EM and possibly prevent migraine chronification. Migraine has a complex relationship with sleep. The use of objective sleep study such as polysomnographic microstructural sleep analysis and actigraphy could help connect sleep disturbances and processes related to CM. Future longitudinal studies should examine whether effective behavioral treatments such as CBTi can reverse migraine chronification.

Chronic Daily Headache in Children and Adolescents: A Multi-Faceted Syndrome

Chronic daily headache (CDH) is a multi-faceted, often complex pain syndrome in children and adolescents. Chronic daily headache may be primary or secondary. Chronic migraine and chronic tension-type are the most frequent subtypes. Chronic daily headache is co-morbid with adverse life events, anxiety and depressive disorders, possibly with other psychiatric disorders, other pain syndromes and sleep disorders; these conditions contribute to initiating and maintaining CDH. Hence, early management of episodic headache and treatment of associated conditions are crucial to prevention. There is evidence for the benefit of psychological therapies, principally relaxation and cognitive behavioral, and promising information on acupuncture for CDH. Data on drug treatment are based primarily on open label studies. The controversies surrounding CDH are discussed and proposals for improvement presented. The multifaceted nature of CDH makes it a good candidate for a multi-axial classification system. Such an approach should facilitate biopsychosocial management and enhance consistency in clinical research.

OnabotulinumtoxinA improves quality of life and reduces impact of chronic migraine over one year of treatment: Pooled results from the PREEMPT randomized clinical trial program

BACKGROUND

Chronic migraine (CM) is associated with high impact and reduced health-related quality of life (HRQoL).

METHODS

Patients with CM from PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) were randomized (1:1) to receive onabotulinumtoxinA or placebo for two 12-week cycles in the double-blind (DB) phase, followed by three 12-week cycles of open-label (OL) onabotulinumtoxinA (onabotulinumtoxinA/onabotulinumtoxinA (O/O) and placebo/onabotulinumtoxinA (P/O) groups, respectively). HRQoL endpoints were assessed over 56 weeks using the Headache Impact Test (HIT-6) and the Migraine-Specific Quality of Life Questionnaire (MSQ). HIT-6 score reductions ≥2.3 and ≥5 denoted between-group minimally important difference and within-patient clinically meaningful response, respectively.

RESULTS

A total of 1236 participants (O/O, n = 607; P/O, n = 629) participated in both phases. The DB phase showed significantly reduced HIT-6 and MSQ for onabotulinumtoxinA versus placebo (all p < 0.001). The OL phase showed significantly reduced HIT-6 for O/O versus P/O at weeks 28, 36, and 48, but not 56. All three MSQ domains showed improved HRQoL relative to baseline, but only the role restrictive domain showed a significant difference between O/O and P/O at week 56.

CONCLUSIONS

Benefits of onabotulinumtoxinA on HRQoL versus baseline persisted throughout the OL phase. Statistical superiority in favor of O/O was demonstrated for HIT-6 through 48 weeks and for MSQ (role restrictive) at 56 weeks.

OnabotulinumtoxinA for chronic migraine: a critical appraisal

Chronic migraine (CM) is a severe disabling condition with a few available evidence-based management options. OnabotulinumtoxinA (onaBoNTA) is approved for use in a number of disorders. Its benefits and potential use in migraine were observed incidentally while treating patients cosmetically for wrinkles. The mechanism of action of onaBoNTA in CM is not fully understood, but there is evidence that this involves axonal transport via sensory fibers. The Phase III REsearch Evaluating Migraine Prophylaxis Therapy trials have established the efficacy as well as the long-term safety and tolerability of onaBoNTA in CM. This review will discuss the evidence behind its use in this setting.

The impact of chronic migraine: The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study methods and baseline results

Background

Longitudinal migraine studies have rarely assessed headache frequency and disability variation over a year.

Methods

The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study is a cross-sectional and longitudinal Internet study designed to characterize the course of episodic migraine (EM) and chronic migraine (CM). Participants were recruited from a Web-panel using quota sampling in an attempt to obtain a sample demographically similar to the US population. Participants who passed the screener were assessed every three months with the Core (baseline, six, and 12 months) and Snapshot (months three and nine) modules, which assessed headache frequency, headache-related disability, treatments, and treatment satisfaction. The Core also assessed resource use, health-related quality of life, and other features. One-time cross-sectional modules measured family burden, barriers to medical care, and comorbidities/endophenotypes.

Results

Of 489,537 invitees, we obtained 58,418 (11.9%) usable returns including 16,789 individuals who met ICHD-3 beta migraine criteria (EM (<15 headache days/mo): n = 15,313 (91.2%); CM (≥15 headache days/mo): n = 1476 (8.8%)). At baseline, all qualified respondents (n = 16,789) completed the Screener, Core, and Barriers to Care modules. Subsequent modules showed some attrition (Comorbidities/Endophenotypes, n = 12,810; Family Burden (Proband), n = 13,064; Family Burden (Partner), n = 4022; Family Burden (Child), n = 2140; Snapshot (three months), n = 9741; Core (six months), n = 7517; Snapshot (nine months), n = 6362; Core (12 months), n = 5915). A total of 3513 respondents (21.0%) completed all modules, and 3626 (EM: n = 3303 (21.6%); CM: n = 323 (21.9%)) completed all longitudinal assessments.

Conclusions

The CaMEO Study provides cross-sectional and longitudinal data that will contribute to our understanding of the course of migraine over one year and quantify variations in headache frequency, headache-related disability, comorbidities, treatments, and familial impact.

The blink reflex test does not show abnormalities in a large group of patients with chronic migraine

The blink reflex - a simple, non-invasive and inexpensive test - may be indicative of lesions or dysfunctions of the brainstem, and particularly assesses the trigeminal-facial arch. Results from alterations of the blink reflex in patients with headaches have provided controversial data.

METHOD

Registration of the waves R1 and R2 (ipsilateral to the stimulus) and R2c (contralateral to the stimulus) by electroneuromyography.

RESULTS

A large number of controls (n=160) and patients with chronic migraine (n=160) were studied. No significant differences were observed between the two groups.

CONCLUSION

It is possible that this relatively simple and primitive reflex is not affected unless there is significant damage to the brainstem.

Chronic migraine

The second edition of the International Classification of Headache Disorders revised in 2006 (ICHD-2R) gives a definition which requires 15 or more headache days per month over the past 3months with at least eight headache days per month that meet criteria for migraine without aura or that responds to migraine specific treatment. Approximately 2% of the global population suffers of chronic migraine (CM). Frequency of headache and degree of disability distinguish CM from episodic migraine (EM). There is a high frequency of medication overuse. The treatment depends on evaluation with education, lifestyle modifications, and trigger management, behavioral and pharmacologic therapies.

Comparisons of disability, quality of life, and resource use between chronic and episodic migraineurs: a clinic-based study in Taiwan

BACKGROUND

The International Burden of Migraine Study (IBMS) showed chronic migraine (CM) was associated with a higher disease burden than episodic migraine (EM). However, in this study Asians with CM were underrepresented. Objectives We investigated if CM and EM differed in headache-related disability, health-related quality of life (HRQoL) and health care resource utilization in Taiwan.

METHODS

This study recruited patients with EM and CM from two headache clinics in Taiwan. Diagnosis was made by physicians based on Silberstein-Lipton criteria. Participants completed a questionnaire including sociodemographics, Migraine Disability Assessment (MIDAS), EuroQol five-dimensions (EQ-5D), Migraine-Specific Quality of Life v2.1 (MSQ), Patient Health Questionnaire-4 (PHQ-4), productivity and health care resource utilization.

RESULTS

A total of 331 patients (EM, n = 164 (49.5%); CM, n = 167 (50.5%)) completed the study. CM patients reported a significantly higher MIDAS score, lower generic (EQ-5D visual analogue scale score and EQ-5D index score) and migraine-specific (all three domains of MSQ) HRQoL, higher levels of anxiety and depression (PHQ-4 ≥ 6) and greater health care resource utilization and productivity loss than those with EM. Positive correlations were found between these instruments and levels of anxiety and depression.

CONCLUSION

Compared to EM, CM was significantly associated with higher disability, lower HRQoL and greater health care resource utilization and productivity loss.

Psychiatric comorbidities of episodic and chronic migraine

Migraine is a prevalent disabling neurological disorder associated with a wide range of medical and psychiatric comorbidities. Population- and clinic-based studies suggest that psychiatric comorbidities, particularly mood and anxiety disorders, are more common among persons with chronic migraine than among those with episodic migraine. Additional studies suggest that psychiatric comorbidities may be a risk factor for migraine chronification (i.e., progression from episodic to chronic migraine). It is important to identify and appropriately treat comorbid psychiatric conditions in persons with migraine, as these conditions may contribute to increased migraine-related disability and impact, diminished health-related quality of life, and poor treatment outcomes. Here, we review the current literature on the rates of several psychiatric comorbidities, including depression, anxiety, and post-traumatic stress disorder, among persons with migraine in clinic- and population-based studies. We also review the link between physical, emotional, and substance abuse, psychiatric disorders, and migraine. Finally, we review the data on psychiatric risk factors for migraine chronification and explore theories and evidence underlying the comorbidity between migraine and these psychiatric disorders.

OnabotulinumtoxinA (BOTOX®): a review of its use in the prophylaxis of headaches in adults with chronic migraine

This article reviews the pharmacology, therapeutic efficacy and tolerability profile of intramuscularly injected onabotulinumtoxinA (onaBoNTA; BOTOX®) for headache prophylaxis in adults with chronic migraine, with a focus on UK labelling for the drug. The pharmacological actions of onaBoNTA include a direct antinociceptive (analgesic) effect; while not fully understood, the mechanism of action underlying its headache prophylaxis effect in chronic migraine is presumed to involve inhibition of peripheral and central sensitization in trigeminovascular neurones. Pooled findings from two large phase III studies of virtually identical design (PREEMPT [Phase III REsearch Evaluating Migraine Prophylaxis Therapy] 1 and 2) showed that treatment with up to five cycles of onaBoNTA (155-195 units/cycle) at 12-week intervals was effective in reducing headache symptoms, decreasing headache-related disability, and improving health-related quality of life (HR-QOL) in patients with chronic migraine, approximately two-thirds of whom were overusing acute headache medications at baseline. During the double-blind phase of both trials, significantly more patients treated with onaBoNTA (two cycles) than placebo experienced clinically meaningful improvements in the monthly frequencies of headache days, moderate to severe headache days and migraine days, and in the cumulative hours of headache on headache days/month. OnaBoNTA therapy also resulted in statistically significant and clinically meaningful improvements in functioning and HR-QOL compared with placebo. Notably, improvements in headache symptoms, functioning and HR-QOL favouring onaBoNTA over placebo were seen regardless of whether or not patients were medication overusers and irrespective of whether or not they were naive to (oral) prophylactic therapy. Further improvements relative to baseline in headache symptoms, functioning and HR-QOL were observed during the open-label extension phase of both trials (all patients received three cycles of onaBoNTA). Treatment with up to five cycles of onaBoNTA was generally well tolerated in the PREEMPT trials. Treatment-related adverse events reported by onaBoNTA recipients (e.g. neck pain, facial paresis and eyelid ptosis) were consistent with the well established tolerability profile of the neurotoxin when injected into head and neck muscles; no new safety events were observed. Debate surrounding the PREEMPT studies has centred on the small treatment effect of onaBoNTA relative to placebo, the possibility that blinding was inadequate and the relevance of the evaluated population. Nonetheless, the totality of the data showed that onaBoNTA therapy produced clinically meaningful improvements in headache symptoms, functioning and HR-QOL; on the basis of these trials, it has become the first (and so far only) headache prophylactic therapy to be specifically approved for chronic migraine in the UK and US. Overall, onaBoNTA offers a beneficial, acceptably tolerated and potentially convenient option for the management of this highly disabling condition, for example in patients who are refractory to oral medications used for prophylaxis.

Chronic migraine classification: current knowledge and future perspectives

In the field of so-called chronic daily headache, it is not easy for migraine that worsens progressively until it becomes daily or almost daily to find a precise and universally recognized place within the current international headache classification systems. In line with the 2006 revision of the second edition of the International Classification of Headache Disorders (ICHD-2R), the current prevailing opinion is that this headache type should be named chronic migraine (CM) and be characterized by the presence of at least 15 days of headache per month for at least 3 consecutive months, with headache having the same clinical features of migraine without aura for at least 8 of those 15 days. Based on much evidence, though, a CM with the above characteristics appears to be a heterogeneous entity and the obvious risk is that its definition may be extended to include a variety of different clinical entities. A proposal is advanced to consider CM a subtype of migraine without aura that is characterized by a high frequency of attacks (10-20 days of headache per month for at least 3 months) and is distinct from transformed migraine (TM), which in turn should be included in the classification as a complication of migraine. Therefore, CM should be removed from its current coding position in the ICHD-2 and be replaced by TM, which has more restrictive diagnostic criteria (at least 20 days of headache per month for at least 1 year, with no more than 5 consecutive days free of symptoms; same clinical features of migraine without aura for at least 10 of those 20 days).

Chronic migraine: epidemiology and disease burden

Chronic migraine is a common and disabling complication of migraine with a population prevalence of about 2%. Emerging evidence suggests that episodic migraine and chronic migraine differ not only in degree, but also in kind. Compared with patients with episodic migraine, those with chronic migraine have worse socioeconomic status, reduced health-related quality of life, increased headache-related burden (including impairment in occupational, social, and family functioning), and greater psychiatric and medical comorbidities. Each year, approximately 2.5% of patients with episodic migraine develop new-onset chronic migraine (ie, chronification). Understanding the natural disease course, improving treatment and management, and preventing the onset could reduce the enormous individual and societal burden of chronic migraine, and thus, have become important goals of headache research. This review provides a summary of the history of nomenclature and diagnostic criteria, as well as recent studies focusing on the epidemiology, natural history, and burden of chronic migraine.

Chronic migraine: Classification and comparisons

Objective: The objective of our study was to field test different chronic migraine (CM) criteria and compare CM epidemiological profiles, which include demographic, personal, and lifestyle characteristics, with high-frequency episodic migraine (HFEM) and low-frequency episodic migraine (LFEM).

Methods: Questionnaires were mailed to a random sample of 18,000 18–65-year-olds in demographically diverse regions of Germany. The epidemiological data for the three classifications of CM, LFEM and HFEM were assessed using descriptive statistics, Pearson Chi-square, and analysis of variance tests.

Results: Among 9350 respondents, CM_I was the most restrictive ( N = 37, 0.4%), followed by CM_II ( N = 45, 0.5%) and CM_III ( N = 185, 2.0%). CM groups did not differ in distribution by age, gender, body mass index, education or smoking and alcohol consumption. Compared to those with LFEM and HFEM, those with CM (CM_III) had significantly different epidemiological profiles.

Conclusions: CM prevalence varies by case definition. The epidemiological profiles of the three CM groups are similar but differ significantly from those of HFEM and LFEM. Optimal definitions for clinical practice and epidemiological research require additional field testing.

Epidemiological classification and social impact of chronic headache

The current prevalent opinion is that a diagnosis of chronic headache should be established in patients who have had a form of primary headache other than cluster headache on at least 15 days a month for at least 3 months. Chronic headache so defined includes four different subtypes: hemicrania continua and new daily persistent headache--two rare forms currently included in the group "Other primary headaches" of the 2004 International Classification of Headache Disorders, second edition (ICHD-II)--chronic tension-type headache, and chronic migraine. Regarding the latter, which has been better known lately as transformed migraine, the current revised diagnostic criteria establish that migraine must be present on at least 8 of the at least 15 days of headache per month and that there must not be any overuse of symptomatic medication. Chronic headache affects about 3-5% of the general population and results in a variety of negative repercussions both on individuals and on society at large.

Disability, HRQoL and resource use among chronic and episodic migraineurs: results from the International Burden of Migraine Study (IBMS)

BACKGROUND

Migraine imposes significant burden on patients, their families and health care systems. In this study, we compared episodic to chronic migraine sufferers to determine if migraine status predicted headache-related disability, health-related quality of life (HRQoL) and health care resource utilization.

METHODS

A Web-based survey was administered to panelists from nine countries. Participants were classified as having chronic migraine (CM), episodic migraine (EM) or neither using a validated questionnaire. Data collected and then analyzed included sociodemographics, clinical characteristics, Migraine Disability Assessment, Migraine-Specific Quality of Life v2.1, Patient Health Questionnaire and health care resource utilization.

FINDINGS

Of the respondents, 5.7% had CM and 94.3% had EM, with CM patients reporting significantly more severe disability, lower HRQoL, higher levels of anxiety and depression and greater health care resource utilization compared to those with EM.

INTERPRETATION

These results provide evidence that will enhance our understanding of the factors driving health care costs and will contribute to development of cost-effective health care strategies.

Proposal for a new classification of chronic headache

Since the publication of the second edition of the International Classification of Headache Disorders (ICHD-2) in 2004, a fiery debate has been raging about chronic daily headache in general and about chronic migraine and medication overuse headache in particular. Based on a number of considerations and observations on the current state of knowledge, a proposal is advanced that suggests a few changes to ICHD-2, namely: (1) differentiation of migraine without aura at the second-digit level into infrequent, frequent and very frequent, based on frequency of attacks. (2) Inclusion of transformed migraine among the complications of migraine; this entry should be coded to 1.5.1 replacing chronic migraine and the only diagnostic criterion that needs to be changed over those already listed in the revised ICHD-2 (ICHD-2R) is its temporal pattern (more than 20 days/month for 1 year or more and never with more than 5 headache-free consecutive days). (3) Differentiation of transformed migraine at the fourth-digit level depending on the presence or absence of symptomatic medication overuse (i.e. use for more than 20 days/month) regardless of whether overuse played any role in the worsening of the headache. (4) Switching of medication overuse headache to the Appendix with other diagnostic criteria to be defined.

The efficacy of withdrawal therapy in subjects with chronic daily headache and medication overuse following prophylaxis with topiramate and amitriptyline

Management of patients affected by chronic daily headache (CDH) with medication overuse constitutes one of the most important unresolved problems. The uncertainty regarding the classification and the prophylaxis are a remarkable part of this problem. Objectives are to: (1) to evaluate the efficacy of withdrawal therapy following prophylaxis with topiramate and amitriptyline in a population affected by CDH and medication overuse with follow-up at 1 (T1), 3 (T2) and 6 (T3) months; (2) to identify which group of the Silberstein's CDH classification (1994) may benefit from this protocol. Inclusion criteria are patients with CDH (headache for more >15 days/month for at least 3 consecutive months) and medication overuse according with IHS second edition (8.2 group); exclusion criteria are patients with secondary headache. All patients included in the study were hospitalized for 1 week. Type of overuse: combination of medications, 38%; analgesics, 29%; triptans, 29%; opioids, 2%; ergotamines, 2%. During hospitalization the following protocol was applied: desametasone 4 mg i.v./day for 1 week, diazepam 6 mg/day for 10 days and prophylaxis with amitriptylin plus topiramate. This prophylaxis was protracted for at least 6 months. The dosages assumed ranged for amitriptylin from 10 to 20 mg/day and for topiramate from 50 to 100 mg/day. In the last 4 years 105 patients with CDH (age 24-89 years; f 96; m 9) were admitted to the hospital. The protocol was applied in 52 patients (age, 29-65 years; f 49; m 3). At T1, 89% of the patients did not fall again into medication overuse; at T2, 64%; and at T3,45% of the patients remained free from overuse. According to the Silberstein' proposal at T1, 93% of the subjects was affected by transformed migraine; and 7% by tension-type headache. At T3, all the patients free from overuse were affected by transformed migraine. Our data suggest that the patients affected by CDH and medication overuse benefit from withdrawal therapy performed during hospitalization plus prophylaxis with amitriptyline plus topiramate. This combination seems a good pharmacological solution to reduce the risk of relapse.

Frequencies of genetic polymorphisms related to triptans metabolism in chronic migraine

Chronic migraine (CM) prevalence ranges around 1–5%. Most of these patients usually treat their acute attacks with triptans, whose efficacy is extremely variable. A genetic basis for migraine is evident and many susceptibility genes have been described, as well as gene polymorphisms possibly implied in therapy response. Several factors could be involved in the evolution of episodic migraine into a chronic form, such as natural history, psychiatric comorbidity, and the individual’s response to therapy. During a study aimed at detecting connections between genotype and response to triptans administration, we characterized a CM population for polymorphisms in the genes coding for monoamine oxidase A, g-protein beta 3 and the cytochromes CYP3A4 and CYP1A2. Alleles and genotypes distributions were compared with known frequencies of healthy Caucasian populations. A significant association with CM was found for the long allele of monoamine oxidase A 30 bp VNTR and CYP1A2*1F variant. Such genomic analysis is part of an integrated platform able to evaluate different levels of metabolic pathways of drugs in CM and their influence in the chronicization process.