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).

ICHD-3: what changes do we need regarding migraine?

Based on publications on migraine in the medical literature after 2004, the third edition of the International Classification of Headache Disorders (ICHD-3), with publication date early in 2013, will provide a framework to systematize those migraine forms that the second edition (ICHD-2) included in its Appendix. The most needed changes concern so-called chronic migraine. The revised ICHD-2 (ICHD-2R) did introduce appreciable changes to the ICHD-2 diagnostic criteria for chronic migraine. To be more relevant to actual clinical practice, the classification should discriminate between forms of migraine without aura depending on low, medium, or high frequency of attacks. The classification should include transformed migraine, an appellation that seems preferable to chronic migraine, in the group of migraine complications using extended time parameters compared with those currently used in ICHD-2R for chronic migraine. Finally, it should assess the opportunity of a different classification for medication-overuse headache.

Migraine and sleep apnea in the general population.

Objective is to investigate the relationship between migraine and obstructive sleep apnea in the general population. A cross-sectional population-based study. A random age and gender stratified sample of 40,000 persons aged 20-80 years residing in Akershus, Hedmark or Oppland County, Norway, were drawn by the National Population Register. A postal questionnaire containing the Berlin Questionnaire was used to classify respondents to be of either high or low risk of obstructive sleep apnea. 376 persons with high risk and 157 persons with low risk of sleep apnea aged 30-65 years were included for further investigations. They underwent an extensive clinical interview, a physical and a neurological examination by physicians, and in-hospital polysomnography. Those with apnea hypopnoea index (AHI) ≥5 were classified with obstructive sleep apnea. Migraine without aura (MO) and migraine with aura (MA) was diagnosed according to the International Classification of Headache Disorders. MO and MA occurred in 12.5 and 6.8% of the participants with obstructive sleep apnea. The logistic regression analyses showed no relationship between the two types of migraine and obstructive sleep apnea, with adjusted odds ratios for MO 1.15 (0.65-2.06) and MA 1.15 (0.95-2.39). Further, estimates using cutoff of moderate (AHI ≥ 15) and severe (AHI ≥ 30) obstructive sleep apnea, did not reveal any significant relationship between migraine and the AHI. Migraine and obstructive sleep apnea are unrelated in the general population.

Application of ICHD-II criteria for headaches in a TMJ and orofacial pain clinic.

The aim of this study was to identify and diagnose headache in a temporomandibular joint and orofacial pain clinic population using the second edition of The International Classification of Headache Disorder criteria. In 502 temporomandibular disorder and orofacial pain patients, 246 patients (49%) were diagnosed with tension-type headache (TTH), followed by migraine without aura (14.5%), probable migraine (12.9%), migraine with aura (7%), probable TTH (4.8%) and cluster headache (0.2%). The prevalence of headaches was compared between male and female patients, and the prevalence of migraine was found to be higher in women than in men. In evaluating by age, the prevalence of migraine was highest in patients in their 20s and 30s and declined as age increased above 40. TTH showed the highest rate throughout all age groups, but it also decreased as age increased. In this study, the prevalence of migraine was lower than that reported in Dr Kim et al.'s study, and the prevalence of TTH much higher than that reported in the previous study. Of the headache patients, 81.1% presented with masseter muscle pain and 47.8% with temporal muscle pain. This finding suggests that pericranial muscle pain may be an inducing factor of primary headache.

Chronic migraine: current pathophysiologic concepts as targets for treatment.

Chronic daily headache (CDH) affects approximately 4% of the population and exerts a significant degree of disability on its sufferers. Chronic migraine (CM) is a subset of CDH that represents migraine without aura occurring on 15 or more days per month for at least 3 months. Although numerous risk factors are associated with the development of CM, the pathophysiology governing its genesis is largely unknown. The role of neurotransmitters, such as glutamate, as well as disruptions of antinociceptive systems and structures, are implicated in CM and are supported by the fact that treatments targeting these abnormalities are effective.

Analysis of the International Classification of Headache Disorders for diagnosis of migraine and tension-type headache in children.

In 2004, the revised International Classification of Headache Disorders (ICHD-II) was published. This study evaluates: (1) the results obtained from applying ICHD-II to children with primary headaches to distinguish between migraine without aura (MO) and tension-type headache (TTH); and (2) the results obtained from introducing modifications of the classification criteria for MO as suggested by various authors. There were 200 participants (93 males, 107 females; age range 3-17 y, mean 9 y 8 mo [SD 2 y 7 mo]). According to the ICHD-II, MO compared with TTH was characterized by: higher intensity of pain; higher frequency of associated symptoms; and higher number of precipitating factors. The significant difference found between patients with MO/probable MO and those with TTH/probable TTH for the variables used in the ICHD-II shows that these variables describe the two forms well. However, 15.5% of children proved to be unclassifiable, mainly because they could not give information for some criteria; other reasons for this were too short a duration of episodes and the possible overlap of criteria describing probable MO and probable TTH. The frequency of one variable, pulsating pain, significantly increased with age. Reduction of duration to 1 hour for MO produced a statistically non-significant increase in the number of children with MO. Behaviour during attacks was found to be simple to apply in evaluating intensity and therefore was introduced as a new criterion. Severe intensity was related to MO, whereas moderate or low-intensity was related to TTH.

Efficacy of sumatriptan tablets in migraineurs self-described or physician-diagnosed as having sinus headache: a randomized, double-blind, placebo-controlled study.

BACKGROUND: Many patients and physicians interpret episodic headache in the presence or absence of nasal symptoms as "sinus' headache, while ignoring the possible diagnosis of migraine. OBJECTIVE: The purpose of this study was to assess the efficacy and tolerability of sumatriptan succinate 50-mg tablets in patients with migraine presenting with "sinus" headache. METHODS: A randomized, double-blind, placebo-controlled, multicenter study was conducted in adult (aged 18-65 years) migraine patients presenting with self-described or physician-diagnosed "sinus" headache. From November 2001 to March 2002, patients meeting International Headache Society criteria for migraine (with > or =2 of the following: unilateral location, pulsating quality, moderate or severe intensity, aggravation by moderate physical activity; and > or =1 of: phonophobia and phonophobia, nausea and/or vomiting) and with no evidence of bacterial rhinosinusitis were enrolled and randomized in a 1:1 ratio via computer-generated randomization schedule to receive either 1 sumatriptan 50-mg tablet or matching placebo tablet. The primary efficacy end point was headache response (moderate or severe headache pain reduced to mild or no headache pain) at 2 hours after administration. The presence or absence of migraine-associated symptoms and sinus and nasal symptoms was also measured. Tolerability was assessed through patient-reported adverse events (AEs). RESULTS: Two hundred sixteen patients with self-described or physician-diagnosed "sinus" headache received a migraine diagnosis and treated 1 migraine attack with sumatriptan 50 mg. The efficacy (intent-to-treat) analysis included 215 patients treated with sumatriptan 50 mg (n = 108; mean [SD] age, 39.6 [12.3] years; mean [SD] weight, 77.7 [17.7] kg; sex, 71% female; race, 69% white) or placebo (n = 107; mean [SD] age, 41.0 [11.3] years; mean [SD] weight 80.7 [20.9] kg; sex, 69% female; race, 64% white). Significantly more patients treated with sumatriptan 50 mg achieved a positive headache response at 2 and 4 hours after administration compared with those treated with placebo (69% vs 43% at 2 hours and 76% vs 49% at 4 hours, respectively; both, P < 0.001). Significantly more sumatriptan-treated patients were free from sinus pain compared with placebo recipients at 2 hours (63% vs 49% placebo, P = 0.049) and 4 hours (77% vs 55%, P = 0.001). All treatments were generally well tolerated. The most common drug-related AEs reported in the sumatriptan and placebo groups, respectively, were dizziness (5% vs < 1%), nausea (3% vs 2%), other pressure/tightness (defined as sense of heaviness; heaviness of upper body, upper extremities; jaw tension; neck tension) (4% vs 0%), and temperature sensations (defined as warm feeling of back of neck, or flushing) (2% vs 0%). No patients experienced any serious AEs. CONCLUSIONS: Sumatriptan 50-mg tablets were effective and generally well tolerated in the treatment of these patients presenting with migraine headaches that were self-described or physician-diagnosed as sinus headaches.

Migraine with aura and migraine without aura are not distinct entities: further evidence from a large Dutch population study.

It is often debated whether migraine with aura (MA) and migraine without aura (MO) are etiologically distinct disorders. A previous study using latent class analysis (LCA) in Australian twins showed no evidence for separate subtypes of MO and MA. The aim of the present study was to replicate these results in a population of Dutch twins and their parents, siblings and partners (N = 10,144). Latent class analysis of International Headache Society (IHS)-based migraine symptoms resulted in the identification of 4 classes: a class of unaffected subjects (class 0), a mild form of nonmigrainous headache (class 1), a moderately severe type of migraine (class 2), typically without neurological symptoms or aura (8% reporting aura symptoms), and a severe type of migraine (class 3), typically with neurological symptoms, and aura symptoms in approximately half of the cases. Given the overlap of neurological symptoms and nonmutual exclusivity of aura symptoms, these results do not support the MO and MA subtypes as being etiologically distinct. The heritability in female twins of migraine based on LCA classification was estimated at .50 (95% confidence intervals [CI] .27 - .59), similar to IHS-based migraine diagnosis (h2 = .49, 95% CI .19-.57). However, using a dichotomous classification (affected-unaffected) decreased heritability for the IHS-based classification (h2 = .33, 95% CI .00-.60), but not the LCA-based classification (h2 = .51, 95% CI .23-.61). Importantly, use of the LCA-based classification increased the number of subjects classified as affected. The heritability of the screening question was similar to more detailed LCA and IHS classifications, suggesting that the screening procedure is an important determining factor in genetic studies of migraine.

Recurrent headache in chinese children: any agreement between clinician diagnosis and symptom-based diagnoses using the International Classification of Headache Disorders (Second Edition)?

There has been a lack of published data on the pattern of recurrent headache in Chinese children. The validity of the International Classification of Headache Disorders criteria has not been evaluated in Chinese children. We performed a retrospective medical record review of 124 children aged <18 years with an International Classification of Diseases coding of headache followed up in a general outpatient clinic in a university-based hospital over a 3-year period (2000-2002). The aims of our study were to (1) study the pattern of recurrent headache in Chinese children and (2) study any agreement between clinical diagnoses made by our board-certified pediatricians and symptom-based diagnoses using the second edition of the International Classification of Headache Disorders (International Classification of Headache Disorders-II). The most common type was unclassified headache (70.2%), followed by infrequent episodic tension-type headache (24.2%) and migraine without aura (5.6%). A family history of headache or migraine was more commonly found in children with infrequent episodic tension-type headache or migraine without aura (P = .0109). The co-occurrence of abdominal pain with infrequent episodic tension-type headache was 30%; for unclassified headache, it was 19.5%. Dysmenorrhea occurred in 7.1% of girls with infrequent episodic tension-type headache and 8.6% of girls with unclassified headache. However, migraine without aura was not associated with abdominal pain or dysmenorrhea. Children with migraine without aura were more frequently referred to child neurologists (P = .0207) and admitted (P = .0000). Neurologic investigations, including electroencephalography, computed tomography, or magnetic resonance imaging of the brain, were performed in less than 30% of cases. Abnormal results were found in only seven cases; with two referred to a neurosurgeon and none requiring surgical intervention. Thus, by using the clinical diagnosis of our board-certified pediatricians as the standard, the sensitivity and specificity of International Classification of Headache Disorders-II-based definition of migraine without aura was 23.1% and 93.4%, respectively, and for infrequent episodic tension-type headache, it was 37.5% and 76%, respectively. The typical characteristics of migraine tend to emerge later and might have led to underdiagnosis of the younger age group, with a higher rate of referral and inpatient management. The new edition of the International Classification of Headache Disorders criteria is still restrictive in clinical practice and might not be able to reflect current pediatric practice. Further studies with a defined study period or recurrent headache might be more useful in analyzing the use of these new International Classification of Headache Disorders criteria in the diagnosis of recurrent headache in children.

Diagnostic criteria of pediatric migraine without aura.

The objectives of this study were to assess the validity of the International Classification of Headache Disorders-I (ICHD-I) and the International Headache Society-Revised (IHS-R) criteria and to evaluate the other headache features that are not included in these criteria for migraine without aura in the pediatric population. One hundred and thirty-two children who referred to our clinic with the complaint of chronic or recurrent headache were evaluated. Clinical diagnosis of the pediatric neurologist was used as the gold standard in evaluating the validity of ICHD-I and IHS-R criteria and the other headache features. After eliminating patients with other migraine types, secondary headache, and missing data, 92 patients were included in the study according to their records. Sixty-one children (66.3%) were diagnosed as migraine without aura. Using the clinical diagnosis as the gold standard, the specificity of ICHD-I criteria was detected as 93.5%, while the sensitivity was detected as 36.1%. IHS-R criteria had 90.3% specificity and 78.7% sensitivity. Relief of headache with sleeping or lying down in a dark, quiet room was found to be the highest specific and sensitive factor of the other headache features not included in these criteria. IHS-R criteria were found to be more valid in the diagnosis of migraine without aura than ICHD-I criteria. IHS-R criteria are recommended both in clinical practice and in the studies requiring migraine without aura case definitions in the pediatric population.

Validation of the classification of migraine without aura (IHS A1.1) proposed in ICHD-2.

OBJECTIVE: This study attempts to validate the alternative criteria for classification of migraine without aura (International Headache Society [IHS] A1.1) proposed in the appendix of The International Classification of Headache Disorders, 2nd edition. This method uses at least two of the associated symptoms (nausea, vomiting, photophobia, phonophobia, and osmophobia) in category D of the IHS classification. BACKGROUND: In the appendix of The International Classification of Headache Disorders, 2nd edition, an alternative method of classification of migraine without aura is proposed. This method of classification has never been validated. METHODS: A total of 1480 consecutive headache patients in a tertiary care setting were evaluated at first visit. Headache-associated features, such as intensity, lifetime duration, frequency per month, duration, triggers, prodrome, percentage recurrence, and postdrome frequency, were recorded. In addition, medication satisfaction, acute and monthly disability, grading of headache days, sleep normality, mood, and habits were documented. RESULTS: Of the 1480 patients, 901 were initially classified as having migraine IHS 1.1. Using the proposed alternative method (IHS A1.1), 885 (98.2%) of these patients were reclassified as having migraine. The remaining 16 (1.8%) patients not classified had only nausea and none of the other specified associated symptoms. They also exhibited different characteristics from the IHS migraine population as a whole regarding their headache and other features. CONCLUSIONS: This classification of migraine in a headache center population shows that the proposed use of any two of nausea, vomiting, photophobia, phonophobia, and osmophobia in category D of the classification may be a valid alternative method of classification. This study also demonstrates that the standard IHS methodology includes a very small group of patients who appear to be different from other migraine patients.

New international classification of migraine with aura (ICHD-2) applied to 362 migraine patients.

The International Classification of Headache Disorders 2nd edition (ICHD-2) subdivides migraine with aura (MA) differently from the ICHD-1 and includes new diagnostic criteria. The aim of the present study was to evaluate how the new classification works in practice and in comparison with the ICHD-1. The patients were recruited from a screen of the Danish National Patient Registry and from Danish neurologists. We included 362 patients diagnosed with MA according to the ICHD-1 in a validated semistructured physician-conducted interview. According to the ICHD-2, 89% (322 of 362) had MA and 11% (40 of 362) had probable MA. The MA patients had one or more ICHD-2 subtype of MA: 54% (173 of 322) had typical aura with migraine headache (MA-MH), 40% (129 of 322) had typical aura with non-migraine headache (MA-NMH), 37% (120 of 322) had aura without headache (MA-WOH), and 7% (26 of 322) had basilar-type migraine (MA-B). Of patients with MA-MH 34% (59 of 173) had co-occurrence of MA-WOH, 9% (16 of 173) had co-occurrence of MA-B and 5% (8 of 173) had co-occurrence of both MA-WOH and MA-B. Of patients with MA-NMH 27% (35 of 129) had co-occurrence of MA-WOH. Only 6% (18 of 322) of the MA patients had exclusively MA-WOH and <1% (2 of 322) had exclusively MA-B. Patients with MA-MH had an earlier age at onset (P = 0.044), an increased lifetime number of MA attacks (P = 0.054) and a higher co-occurrence of migraine without aura (P = 0.002) than patients with MA-NMH. Patients with MA-B tended to have an earlier age at onset and more severe attacks and patients with MA-WOH had a higher age at onset and less severe attacks than patients with MA-MH. The variations between ICHD-2 subtypes of MA indicate that patients with similar subtype of MA share phenotype and very likely have similar underlying aetiology.

Latent class and genetic analysis does not support migraine with aura and migraine without aura as separate entities.

Latent class and genetic analyses were used to identify subgroups of migraine sufferers in a community sample of 6,265 Australian twins (55% female) aged 25-36 who had completed an interview based on International Headache Society (IHS) criteria. Consistent with prevalence rates from other population-based studies, 703 (20%) female and 250 (9%) male twins satisfied the IHS criteria for migraine without aura (MO), and of these, 432 (13%) female and 166 (6%) male twins satisfied the criteria for migraine with aura (MA) as indicated by visual symptoms. Latent class analysis (LCA) of IHS symptoms identified three major symptomatic classes, representing 1) a mild form of recurrent nonmigrainous headache, 2) a moderately severe form of migraine, typically without visual aura symptoms (although 40% of individuals in this class were positive for aura), and 3) a severe form of migraine typically with visual aura symptoms (although 24% of individuals were negative for aura). Using the LCA classification, many more individuals were considered affected to some degree than when using IHS criteria (35% vs. 13%). Furthermore, genetic model fitting indicated a greater genetic contribution to migraine using the LCA classification (heritability, h(2)=0.40; 95% CI, 0.29-0.46) compared with the IHS classification (h(2)=0.36; 95% CI, 0.22-0.42). Exploratory latent class modeling, fitting up to 10 classes, did not identify classes corresponding to either the IHS MO or MA classification. Our data indicate the existence of a continuum of severity, with MA more severe but not etiologically distinct from MO. In searching for predisposing genes, we should therefore expect to find some genes that may underlie all major recurrent headache subtypes, with modifying genetic or environmental factors that may lead to differential expression of the liability for migraine.

Migraine aggravation caused by cephalic venous congestion.

BACKGROUND: Cerebral venous distension is thought by some to serve as a source of migraine pain. Previous investigators have tried to modify pain intensity by induction of additional venous congestion via compression of both internal jugular veins (Queckenstedt's maneuver). The magnitude of blood flow within the internal jugular veins depends markedly on body position, and inconsistencies in positioning may have influenced their results. OBJECTIVE: To investigate the effect of Queckenstedt's maneuver, performed both in the upright and in the supine body position, in migraineurs during an acute attack. METHODS: Twenty-five patients (18 women, 7 men; mean age +/- SD, 35.4 +/- 13.3 years) with International Headache Society-defined migraine without aura were evaluated. Queckenstedt's maneuver was performed in both body positions during an acute migraine attack, involving constant application of manual pressure to both internal jugular veins for 30 seconds. Headache intensity was rated before, during, and after Queckenstedt's maneuver on a scale extending from 1 (mild) to 10 (intolerable). RESULTS: Seventeen patients (68%) reported an increase of headache intensity in the supine position during Queckenstedt's maneuver. In the sitting position, pain increase was observed only in 6 patients (24%). The magnitude of pain increase was significantly greater in the supine position compared to the upright position (P=.02). CONCLUSIONS: Our results support a role for cerebral venous congestion in the generation of migraine pain and suggest body position may influence the clinical expression of that process.

Chronic daily headache in a tertiary care population: correlation between the International Headache Society diagnostic criteria and proposed revisions of criteria for chronic daily headache.

The International Headache Society (IHS) has been criticized for its approach to classification of chronic daily headache (CDH); Silberstein and Lipton criteria provide an alternative to this approach. The aim of this study is to apply the alternative diagnostic approaches to a sample of CDH patients consulting in specialty care. Our sample consisted of 638 patients with CDH. Patients were classified according to both classification systems. Patients were predominantly female (65.0%), with ages ranging from 11 to 88 years. According to the Silberstein and Lipton classification, we found eight different diagnoses. The most common diagnosis was chronic migraine (87.4%), followed by new daily persistent headache (10.8%). Just six patients had chronic tension-type headache (CTTH). Applying the IHS criteria we found 14 different diagnoses. Migraine was found in 576 (90.2%) patients. CTTH occurred in 621 (97.3%), with only 10 (1.57%) having this as the sole diagnosis. We conclude that both systems allow for the classification of most patients with CDH when daily headache diaries are available. The main difference is that the IHS classification is cumbersome and requires multiple diagnoses. The Silberstein and Lipton system is easier to apply, and more parsimonious. These findings support revision of the IHS classification system to include chronic migraine.

Characterization of chronic daily headaches in children in a multidisciplinary headache center.

BACKGROUND: Chronic daily headaches (CDH) occur in >4% of the adult population. The criteria for CDH, however, are controversial. In children, the characterization of frequent headaches and CDH is limited. METHODS: A Headache Center to characterize headaches in children (3 to 18 years old) was established. Over 34 months, 577 children have been evaluated. With use of a definition of > or =15 headaches per month, 200 (34.6%) children had CDH. RESULTS: The average age at the first headache in these children was 9.3 +/- 3.6 years, whereas the average age at presentation to the Headache Center was 12.5 +/- 3.1 years. Sixty-eight percent were girls, 88% were Caucasian, and 11% were African American. Ninety-two percent clinically had migraine headaches, whereas 60.5% met the International Headache Society migraine criteria. The pain was pulsatile in 79%, 63.5% had nausea with or without vomiting, and 59.5% had photophobia and phonophobia. Three subcategories emerged, with 37% having frequent headaches but not daily, 43.5% having episodic daily headaches, and 19.5% having a continuous headache. CONCLUSION: The features of CDH in children most closely match those of migraine. A clear division of these children using frequency identifies three groups: frequent headaches (15 to 29), daily intermittent, and daily continuous. The daily continuous group is the most unique; however, the nature of these headaches continues to remain migrainous.