Childhood Maltreatment and Migraine (Part II). Emotional Abuse as a Risk Factor for Headache Chronification

(Headache 2010;50:32‐41) Objectives.— To assess in a headache clinic population the relationship of childhood abuse and neglect with migraine characteristics, including type, frequency, disability, allodynia, and age of migraine onset. Background.— Childhood maltreatment is highly prevalent and has been associated with recurrent headache. Maltreatment is associated with many of the same risk factors for migraine chronification, including depression and anxiety, female sex, substance abuse, and obesity. Methods.— Electronic surveys were completed by patients seeking treatment in headache clinics at 11 centers across the United States and Canada. Physician‐determined data for all participants included the primary headache diagnoses based on the International Classification of Headache Disorders‐2 criteria, average monthly headache frequency, whether headaches transformed from episodic to chronic, and if headaches were continuous. Analysis includes all persons with migraine with aura, and migraine without aura. Questionnaire collected information on demographics, social history, age at onset of headaches, migraine‐associated allodynic symptoms, headache‐related disability (The Headache Impact Test‐6), current depression (The Patient Health Questionnaire‐9), and current anxiety (The Beck Anxiety Inventory). History and severity of childhood (<18 years) abuse (sexual, emotional, and physical) and neglect (emotional and physical) was gathered using the Childhood Trauma Questionnaire. Results.— A total of 1348 migraineurs (88% women) were included (mean age 41 years). Diagnosis of migraine with aura was recorded in 40% and chronic headache (≥15 days/month) was reported by 34%. Transformation from episodic to chronic was reported by 26%. Prevalence of current depression was 28% and anxiety was 56%. Childhood maltreatment was reported as follows: physical abuse 21%, sexual abuse 25%, emotional abuse 38%, physical neglect 22%, and emotional neglect 38%. In univariate analyses, physical abuse and emotional abuse and neglect were significantly associated with chronic migraine and transformed migraine. Emotional abuse was also associated with continuous daily headache, severe headache‐related disability, and migraine‐associated allodynia. After adjusting for sociodemographic factors and current depression and anxiety, there remained an association between emotional abuse in childhood and both chronic (odds ratio [OR] = 1.77, 95% confidence intervals [CI]: 1.19‐2.62) and transformed migraine (OR = 1.89, 95% CI: 1.25‐2.85). Childhood emotional abuse was also associated with younger median age of headache onset (16 years vs 19 years, P = .0002). Conclusion.— Our findings suggest that physical abuse, emotional abuse, and emotional neglect may be risk factors for development of chronic headache, including transformed migraine. The association of maltreatment and headache frequency appears to be independent of depression and anxiety, which are related to both childhood abuse and chronic daily headache. The finding that emotional abuse was associated with an earlier age of migraine onset may have implications for the role of stress responses in migraine pathophysiology.     

Coping styles of headache sufferers

Psychological factors are important in the chronification and aggravation of headaches. We studied 90 patients suffering from migraine, chronic daily headache (CDH) evolved from migraine, and episodic or chronic tension-type headache (TTH). Emotional, cognitive, and behavioral pain coping were assessed using the Kiel Pain Inventory (KPI), Beck's Depression Inventory, the State-Trait-Anxiety Inventory, and Quality of Life Questionnaire. In addition, the clinical course of headache was analyzed using a validated headache diary. The results were as follows. Firstly, the KPI is reliable internally for the assessment of pain-coping strategy employment among headache patients. Secondly, migraine sufferers were characterized by pronounced psychological abnormalities during the headache phase, demonstrating a less adaptive coping behavior. This was in contrast to the TTH patients, who showed more general distress manifesting in elevated anxiety and lower quality of life. The only factor which appeared to be essential for differentiating between migraine and TTH was the intensity of headache. Thirdly, chronic TTH and CDH evolved from migraine demonstrated more pronounced psychological disabilities and more severe clinical courses of headaches than episodic TTH or nontransformed migraine. The predictor variable for transformation of migraine was impairment of well-being/quality of life, and for transformation of TTH, the frequency of headaches and depression. Finally, analgesic misuse seems to be less important for chronification and transformation of headaches than the degree of psychological disability. This study draws attention to the role of psychological factors in the chronification of TTH and transformation of migraine and provides some recommendations for the behavioral treatment of chronic headaches.     

Family History for Chronic Headache and Drug Overuse as a Risk Factor for Headache Chronification

Objectives.— To assess whether family history for chronic headache (CH) and drug overuse could represent a risk factor for headache chronification. Background.— Among factors investigated as risk factors for chronification of headache disorders, familial liability for CH and drug overuse has been rarely investigated. Patients and Methods.— A total of 105 consecutive patients with daily or nearly daily headache, and 102 consecutive patients with episodic headache matched by age, sex, and type of headache at onset, underwent a structured direct interview about family history for episodic headache, CH with and without medication overuse, substance abuse/dependence, and psychiatric disorders. Results.— In total, 80 out of 105 patients with CH received a diagnosis of medication overuse headache (MOH), 21 patients were classified as chronic migraine (CM), and 4 as chronic tension‐type headache (CTTH) without drug overuse. Some 38.1% of CH patients reported family history for CH vs only 13.7% of episodic headaches (P = .001). Familiality for CH with medication overuse was reported by 25.7% of cases vs 9.8% of controls (P = .0028). A familial history of substance abuse was reported by 20% of patients vs 5.9% of controls (P = .0026). In all, 28.7% of MOH patients reported family history for CH with medication overuse (P = .0014) and 21.2% for substance abuse (P = .002). Relatives of patients with MOH were more likely than control relatives to suffer from CH (OR = 4.19 [95% CI 2.05‐8.53]), drug overuse (OR = 3.7 [95% CI 1.66‐8.24]), and substance abuse (OR = 4.3 [95% CI 1.65‐11.19]). No differences regarding family history for episodic headache and for psychiatric disorders were found. No differences in family history for CH with drugs overuse and for substance abuse were found between CH patients without overuse and controls. Fifteen CH patients reported family history for alcohol abuse (P = .0003). Conclusions.— The significantly increased familial risk for CH, drug overuse, and substance abuse suggests that a genetic factor is involved in the process of headache chronification.     

The International Headache Society (IHS) Headache Classification as applied to a headache clinic population

Four hundred patients attending a headache clinic were classified using the IHS criteria. The majority required more than two, often three or four, diagnoses. Even though migraine was the most common diagnosis, only 1/4 of those with a migraine diagnosis had it as the only diagnosis. Seventy-five percent of migraine patients had coexistent chronic tension-type headache (CTTH), drug-induced headache or both. Ninety-six percent of patients diagnosed as having migraine with aura also suffered from migraine without aura. More than 1/3 of patients (37.7%) attending the clinic suffered from chronic daily headache (CDH) (chronic cluster headache excluded), which is not included as a separate entity in the IHS classification. Pure CTTH formed only a small minority of CDH, whereas 86.6% of CDH had migraine as one of the diagnoses. Drug-induced headache was a prominent second or third diagnosis. The advantages and disadvantages of multiple verses single diagnosis in CDH and the need to recognize the natural history of headache disorders in the classification are discussed.     

Post-traumatic stress disorder in episodic and chronic migraine

OBJECTIVE: To assess and contrast the relative frequency of self-reported post-traumatic stress disorder (PTSD) in patients with episodic migraine and chronic/ transformed migraine. BACKGROUND: Several risk factors have been identified as risk factors for chronification of headache disorders. Childhood abuse has been suggested as a risk factor for chronic pain in adulthood. In addition depression, as well as several other psychiatric disorders, are co-morbid with migraine. Recent data suggest that PTSD may be more common in headache sufferers than in the general population. METHODS: This was a prospective, pilot study conducted at a headache center. Adult subjects with episodic, chronic, or transformed migraine were included. Demographic information, depression history, body mass index (BMI), and headache characteristics were obtained. PTSD was assessed using the life events checklist (LEC) and the PTSD checklist, civilian version (PCL-C). We contrasted the data from episodicmigraineurs and chronic/transformed migraine participants (CM) and conducted multivariate analyses, adjusting for covariates. RESULTS: Of the 60 participants included, 91.7% were female with a mean age of 41.4+/-12.5 years old. EM was diagnosed in 53.3% and CM in 46.7%. The mean BMI was not significantly different between groups. In contrast, the relative frequency of depression was significantly greater in subjects with CM (55.2%) than EM (21.9%, P=.016). There was no significant difference in the percentage of participants reporting at least 1 significant traumatic life event (LE) or in the mean number of traumatic LEs between EM and CM participants. However, the relative frequency of PTSD reported on the PCL in CM (42.9%) was significantly greater as compared to EM (9.4%, P=.0059. After adjusting for depression and other potential confounders, the difference remained significant P=.023). CONCLUSION: PTSD is more common in CM than in episodic migraineurs. This suggests that PTSD may be a risk factor for headache chronification, pending longitudinal studies to test this hypothesis.     

Prevalence and associated factors for episodic and chronic daily headache in the Colombian population

There are multiple risk factors for chronic daily headache (CDH), but they are usually assessed in an isolated form without an adequate control for confounders. CDH is considered a variant of episodic headache, but studies have not gathered enough evidence to evaluate simultaneously CDH and episodic in the same population. We set out to establish simultaneously the factors associated with chronic daily or episodic headache in a population setting, using a cross-sectional survey in a random sample of 1505 adult urban inhabitants (Bucaramanga, Colombia). The survey asked questions about headache, family and personal history of disease, and consumption or abuse of caffeine, alcohol, hypnotics and analgesics. The association among independent variables and CDH or episodic headache was made with multinomial logistic regression. Female gender, arterial hypertension or cranial trauma history, and a high score in the depression scale are associated with episodic headache and CDH. Parents with CDH, the complaint of multiple arousals during sleep and use of hypnotics are associated with CDH, but not with episodic headache. Age <36 years, alcoholism and snoring are factors associated only with episodic headache. Chronic daily headache and episodic headache have several common risk factors, but there are other factors not shared by both conditions.     

Chronic daily headache in U.S. soldiers after concussion

(Headache 2012;52:732‐738) Objective.— To determine the prevalence and characteristics of, and factors associated with, chronic daily headache (CDH) in U.S. soldiers after a deployment‐related concussion. Methods.— A cross‐sectional, questionnaire‐based study was conducted with a cohort of 978 U.S. soldiers who screened positive for a deployment‐related concussion upon returning from Iraq or Afghanistan. All soldiers underwent a clinical evaluation at the Madigan Traumatic Brain Injury Program that included a history, physical examination, 13‐item self‐administered headache questionnaire, and a battery of cognitive and psychological assessments. Soldiers with CDH, defined as headaches occurring on 15 or more days per month for the previous 3 months, were compared to soldiers with episodic headaches occurring less than 15 days per month. Results.— One hundred ninety‐six of 978 soldiers (20%) with a history of deployment‐related concussion met criteria for CDH and 761 (78%) had episodic headache. Soldiers with CDH had a median of 27 headache days per month, and 46/196 (23%) reported headaches occurring every day. One hundred seven out of 196 (55%) soldiers with CDH had onset of headaches within 1 week of head trauma and thereby met the time criterion for posttraumatic headache (PTHA) compared to 253/761 (33%) soldiers with episodic headache. Ninety‐seven out of 196 (49%) soldiers with CDH used abortive medications to treat headache on 15 or more days per month for the previous 3 months. One hundred thirty out of 196 (66%) soldiers with CDH had headaches meeting criteria for migraine compared to 49% of soldiers with episodic headache. The number of concussions, blast exposures, and concussions with loss of consciousness was not significantly different between soldiers with and without CDH. Cognitive performance was also similar for soldiers with and without CDH. Soldiers with CDH had significantly higher average scores on the posttraumatic stress disorder (PTSD) checklist compared to soldiers with episodic headaches. Forty‐one percent of soldiers with CDH screened positive for PTSD compared to only 18% of soldiers with episodic headache. Conclusions.— The prevalence of CDH in returning U.S. soldiers after a deployment‐related concussion is 20%, or 4‐ to 5‐fold higher than that seen in the general U.S. population. CDH following a concussion usually resembles chronic migraine and is associated with onset of headaches within the first week after concussion. The mechanism and number of concussions are not specifically associated with CDH as compared to episodic headache. In contrast, PTSD symptoms are strongly associated with CDH, suggesting that traumatic stress may be an important mediator of headache chronification. These findings justify future studies examining strategies to prevent and treat CDH in military service members following a concussive injury.     

Transformed or Evolutive Migraine

SYNOPSIS
630 (39%) of 1600 patients seen in a Headache Clinic over a three year period had chronic daily headaches (CDH). In 78% of these CDH patients, the daily headaches evolved out of a prior history of episodic migraine; these patients we designate as having "transformed" or "evolutive" migraine. The other 12% had migraine headaches which were daily from the start.
Patients with transformed migraine, in contrast to those with daily headaches from the start, have a significantly higher incidence of positive family history of migraine, menstrual aggravation of migraine, identifiable trigger factors, associated G.I. and neurological symptoms, and early morning awakening with headache.
The CDH group in general over-used symptomatic medication and exhibited abnormalities on behavioral scale testing. Withdrawal of daily symptomatic medication, institution of a low tyramine low caffeine diet, initiation of prophylactic anti-migraine therapy, and biofeedback and behavioral therapy, gave worthwhile improvement in 76% of chronic daily headache patients.
Factors which promote "evolution" of migraine from intermittent to chronic daily occurrence are not well-defined but may include medication abuse, medication withdrawal, and psychiatric disturbances.     

Managing chronic headaches in the clinic

Chronic daily headache (CDH), which is often linked to a history of migraine, tension-type headache and the abuse of headache medications, and cluster headache are the best known of the chronic headaches. These headaches may not be well recognised or well treated in primary care. This article outlines the development of management algorithms for these headache subtypes, designed for use by the primary care physician with an interest in headache. Principles of care for chronic headaches include implementation of screening procedures, differential diagnosis, tailoring of management to the individual's needs, proactive follow-up and a team approach to care. These principles can be customised to the headache subtype by the selection of appropriate therapies. The optimal treatments for CDH include physical therapy to the neck if there is any stiffness there, withdrawal of abused medications and treatment of any subsequent withdrawal symptoms and headache prophylaxis, together with the provision of acute medications as rescue therapy. Optimal treatments for cluster headache include short- and long-term prophylaxis to prevent the headaches developing and acute medications for use as rescue. If treatment is ineffective, alternative medications can be provided at follow-up, with the possibility of referral for refractory patients.     

Chronic daily headache in a paediatric headache centre

The prevalence and the clinical features of chronic daily headache (CDH) were studied in 968 children and adolescents observed during a period of one year in the Headache Centre of the Anna Meyer Paediatric Hospital of Florence. Nine hundred and fortyfour patients (97.52%) had primary headache according to ICHD-II, 24 subjects had secondary headache and 56 patients had CDH (5.93% of primary headaches). The mean age of subjects with CDH was higher than general (13.5 vs. 11.5 years), with a female preponderance (69.6% vs. 30.4%). According to the ICHD-II, headaches were classified as chronic migraine in 10 patients (1.5.2 ICHD-II), chronic tension-type headache in 36 (2.3 ICHD-II), new daily persistent headache in 8 (4.8 ICHD-II) and 2 patients reported mixed pattern (chronic migraine+chronic tension type headache). Medication overuse was not implicated in our patients.     

Somatic symptoms in headache patients: the influence of headache diagnosis, frequency, and comorbidity

BACKGROUND: Mood disorders of anxiety and depression are well known to be comorbid with primary headache disorders. Less is known of the comorbidity of other somatic symptoms with headache. METHODS: Headache Clinic patients were screened with the Primary Care Evaluation of Mental Disorders (PRIME-MD), a multidimensional psychiatric screening tool. The prevalence of somatic symptoms was compared by headache diagnosis, frequency of severe headache, and psychiatric diagnosis. Follow-up data were obtained 6 months after consultation. RESULTS: Clinical diagnoses and PRIME-MD data were available for 289 patients. Associated somatic symptoms were more frequent in patients with chronic migraine (mean 5.5, P<.001) and chronic daily headache (CDH) (6.3, P=.008) compared to episodic migraine (4.0); in patients with severe headache >2 days per week compared to 2 days per week had significantly higher somatic counts (P=.01). Six-month follow-up data were available for 140 patients. Associated symptoms decreased both for patients with and without decrease in severe headache frequency (mean reduction of 1.0, P=.01 and 0.8, P=.003, respectively). CONCLUSION: Associated somatic symptoms are more common in patients with chronic migraine and CDH, with more frequent severe headaches, and with associated anxiety or depression. Patients with episodic migraine have similar somatic prevalence as a previously studied primary care population. The spectrum of headache disorders may be characterized as showing increasing somatic prevalence as headaches, particularly severe headaches, become more frequent.     

From transformed migraine to episodic migraine: reversion factors

OBJECTIVE: To identify the factors contributing to the reversion of transformed migraine (TM) into episodic migraine. BACKGROUND: TM, the most common and important subtype of chronic daily headache (CDH), has a great effect on a patient's quality of life. However, its clinical course and outcome predictors have rarely been studied prospectively. METHOD: Of 1142 consecutive headache patients seen at the Headache Clinic of the Samsung Medical Center, the patients with TM (frequency >15/month for >6 months and a history of migraine meeting the ICHD-II diagnostic criteria) were followed for at least 1 year. We analyzed the demographic data, clinical course, and compliance factors, such as those of the physician's management protocol and recommended lifestyle modification. RESULTS: A total of 136 patients finished the final follow-up assessment 1 year after the initial evaluation. Ninety-five patients (70%) converted from TM to episodic migraine. Forty-one patients (30%) continued to suffer daily headaches without a period of improvement. The demographic and clinical information collected before the treatment was not significantly related to outcome, except for chronic use of analgesics for other medical conditions (P= .01). Of the compliance factors, good compliance with preventive medication (P < .001), withdrawal from continuous use of analgesics for headache relief (P < .001), and regular exercise (P= .04) were significant positive contributors to the reversion of TM into episodic migraine. CONCLUSION: Compliance factors are the most important factors that determine the reversion of TM into episodic migraine.     

An epidemiological study of headache in Florianopolis, Brazil

The aim of this study was to estimate the 1-year prevalence of headache, migraine, tension-type headache (TTH) and chronic daily headache (CDH), and the degree of association of migraine with some sociodemographic characteristics of the population of Florianopolis, Brazil. This is a cross-sectional, door-to-door, population-based study. In 300 randomly selected households, 625 subjects, aged 15-64 years, responded to a structured questionnaire. The 1-year prevalence of headache was 80.8%, of migraine 22.1%, of TTH 22.9%, and of CDH 6.4%. Migraine and CDH were significantly more prevalent in females than in males. Migraine was significantly associated with the following variables: low household income, low electricity consumption, and divorced or widowed marital status. We have shown high prevalences of migraine and CDH in Florianopolis, close to the higher rates of previous studies. There was a preponderance of migraine in females, divorced or widowed, with a low socioeconomic level.     

Long-term outcome of patients with headache and drug abuse after inpatient withdrawal: five-year follow-up

Thirty-eight patients with "chronic daily" headache and ergotamine and/or analgesics abuse according to the criteria proposed by the international Headache Society were re-investigated 5 years after inpatient drug withdrawal. At the end of the observation period, 19 patients (50.0%) had their headaches on only 8 days per month or less, 18 patients (47.4%) were free of symptoms or had only mild headaches. A close correlation was found between the frequency of headache and the duration of drug abuse, as well as between the intensity of headache and the number of tablets taken per month. Frequency and intensity of headache had changed within the first 2 years after withdrawal, but remained stable afterwards. Fifteen patients (39.5%) reported on recurrent drug abuse. Patients with migraine showed a tendency towards a better prognosis compared to patients with tension-type headache or with combined migraine and tension-type headache. The results of this study highlight the long-term efficacy of inpatient drug withdrawal in patients with headache and ergotamine and/or analgesics abuse.     

Primary chronic daily headache: clinical and pharmacological aspects. A clinic-based study in Oman

This study on primary chronic daily headache was based on the 1996 proposed revision of the diagnostic criteria of the International Headache Society (IHS). To investigate the relative frequency, clinical characteristics, and associated features of primary chronic daily headache in Omani patients, 171 patients visiting the Neurology Clinic at Sultan Qaboos University Hospital were evaluated. Forty-five percent was diagnosed as suffering from primary chronic daily headache (female to male ratio, 1.7:1). Sixty-two percent suffered from transformed migraine and 34% from chronic tension-type headache. The average age across sexes was 32.3 +/- 12.3 years. A dull heavy feeling in the head was reported by 58% of patients and was associated in less than one third with associated features characteristic of migraine. All headache types shared the same trigger factors. All patients were taking medication, predominantly analgesics, at the time of their first visit. We concluded that primary chronic daily headache is very common with the relative frequency of transformed migraine being similar to that found in Mediterranean studies. Also in Oman, chronic use/overuse of analgesics and nonsteroidal anti-inflammatory drugs is a problem that coexists with primary chronic daily headache. Finally, the proposed revised IHS criteria are highly recommended as a standard classification system for this type of headache.     

Quality of life in migraine and chronic daily headache patients

Primary chronic headache can affect a patient's health-related quality of life (HQL). The Medical Outcomes Study Short Form (SF-36) questionnaire has been used to address this issue. We compare the impact of headache on the HQL of patients with migraine and chronic daily headache (CDH) using the SF-36 instrument. We analyzed a group of 115 consecutive patients; 62 migraine patients and 53 CDH patients completed the questionnaire. Patterns of disability were similar between the two groups, but CDH was marked by a lower level of health scales. Patients with CDH had a significantly worse pain score in physical functioning, role functioning (physical), bodily pain, general health perceptions, and mental health than patients with migraine headache. Our results in the migraine group were similar to findings in other publications, with the lowest scores in role functioning (physical) and bodily pain. There is no previous experience in CDH patients, but the present data suggest that the SF-36 questionnaire is valuable in determining the differences in functional status among headache types. These data suggest that the SF-36 is a reliable and valid measure of the HQL of patients with CDH, and may indeed prove to be valuable in studying the efficacy of therapeutic agents for this type of headache.     

Analysis of the patients attending a specialist UK headache clinic over a 3-year period

OBJECTIVE: This study analyzed the profile of patients who attended a specialist UK headache clinic over a 3-year period. METHODS: An audit was conducted of the clinical records of patients attending the specialist headache clinic at King's College, London, between January 1997 and January 2000. Data were collected for diagnoses given, current medications taken, medications prescribed and recommended, and investigations conducted. Results were calculated as numbers and proportions of patients for the 3-year period and for the 3 separate 12-month periods. RESULTS: A total of 458 patients were included in the audit. Most patients were diagnosed as having chronic daily headache (CDH, 60%) or migraine (33%). Prior to the clinic visit, most patients with CDH and migraine treated their headaches with analgesics, and there was little use of prophylactic medication. In the clinic, 74% of patients with CDH and 85% of migraineurs were prescribed prophylactic medication, and 81% of migraineurs were given triptans for acute treatment. Diagnostic testing was performed in 12% of the patients, and all results were normal or negative. CONCLUSIONS: CDH and migraine were the most common headache types encountered in this UK secondary-care clinic. Review of treatment patterns used prior to the initial clinic evaluation suggests that management of CDH and migraine in UK primary care is suboptimal, and educational initiatives are needed to improve headache management.     

From migraine to chronic daily headache: the biological basis of headache transformation

Migraine headache carries the potential of transforming into chronic daily headache (CDH) over a period of time. Although several risk factors for migraine progression to CDH have been identified, the biological basis of this transformation is unknown. In this review, the consequences of stressful life events and medication overuse, 2 risk factors associated with the development of CDH, on brain processes involved in headache are examined. The extensive overlap in both neural circuitry and cellular events that occur with stress, medication overuse, and migraine provide insight into potential mechanisms that may lead to CDH. Particular attention is devoted to the effect of stress and medication overuse on peripheral and central neuroimmune interactions that can facilitate pain signaling. These interactions include the degranulation of mast cells in the dura, causing the sensitization of primary afferent neurons, as well as the activation of glial cells in the brain that can lead to central sensitization. It is hypothesized that the biological processes involved in migraine headache are directly impacted by stress, medication overuse, and other risk factors, resulting in a reduced threshold for induction of headache and transformation of episodic migraine to CDH.     

Chronic Daily Headache in Children and Adolescents

Chronic daily headache (CDH) may be primary or secondary. Secondary causes can be suspected through “red flags” in the history and examination. With a prevalence of at least 1% and several associations, primary CDH is a common, often complex, chronic pain syndrome in children and adolescents. The intricate associations between stressors, psychiatric disorders (especially anxiety and depression), and CDH can be explained by “the limbically augmented pain syndrome” proposed by Rome and Rome. Disorders of sleep and other pain syndromes also may co-occur. For these reasons, a multiaxial classification is ideal. Many with primary CDH have features of both chronic migraine and chronic tension-type headache, contributing to confusion in subtyping. Primary CDH is often transformed from a primary episodic headache type, stressors being most responsible. Genetic factors also may facilitate chronification. Management should be biopsychosocial, family-centered, and often multidisciplinary, drugs being only one component. Treatment is still based on consensus, not evidence. Girls, migraineurs, and those with psychiatric comorbidity, medication overuse, and CDH onset before the age of 13 years and lasting for 2 years or longer, are at high risk for persistence; hence, such patients should be followed up into adult life. A classification for CDH should be included in the third edition of the International Classification of Headache Disorders.     

The prophylactic treatment of chronic daily headache

Chronic daily headache (CDH), a heterogeneous group of headache disorders occurring on at least 15 days per month, affects up to 4% to 5% of the general population. CDH disorders include transformed (or chronic) migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua. Patients with CDH have greater disability and lower quality of life than episodic migraine patients and often overuse headache pain medications. To date, only topiramate, gabapentin, tizanidine, fluoxetine, amitriptyline, and botulinum toxin type A (BoNTA) have been evaluated as prophylactic treatment of CDH in randomized, double-blind, placebo-controlled, or active comparator-controlled trials. The evidence supporting the use of BoNTA as prophylaxis of CDH is composed of larger and longer trials, as over 1000 patients were evaluated for up to 11 months duration. Compared with placebo BoNTA has significantly reduced the frequency of headache episodes, a recommended efficacy measure for headache trials and has been demonstrated to be safe and very well tolerated with few discontinuations due to adverse events. Side effects are generally transient, mild to moderate, and nonsystemic. The results of clinical trials using traditional oral pharmacotherapy, while supportive of their use as prophylactic treatment of CDH, are limited by several factors, including small numbers of patients, the choice of efficacy measures, and short treatment periods. The use of oral agents was associated with systemic side effects, which may limit their effectiveness as prophylactic treatment of CDH.