Genetic epidemiology of migraine and cluster headache

Prevalence of menstrually related migraine and nonmigraine primary headache in female students of Belgrade University

OBJECTIVES

To determine prevalence and characteristics of menstrually related migraine and nonmigraine headache in female students of Belgrade University.

METHODS

A questionnaire was administered to female students during randomly selected classes of the Schools of Medicine and Pharmacy. Diagnoses were assigned according to the criteria of the International Headache Society and MacGregor's stricter definition of "menstrual" migraine.

RESULTS

Of 1943 female students (18 to 28 years old), 1298 (66.8%) had primary headaches. Among 1298 students with headache, 245 (12.6%) had migraine and 1053 (54.2%) had nonmigraine headache. The prevalence rates of migraine versus nonmigraine headache in relation to the menstrual cycle were: premenstrual, 0.9% versus 4.4%; menstrual, 1.5% versus 1.5%; menstrually associated, 6.1% versus 10.1%; menstrually unchanged, 2.7% versus 19.2%; and menstrually unrelated, 1.4% versus 18.9%. Female students with migraine had menstrually related attacks more frequently than students with nonmigraine headache (67.7% versus 29.5%). This difference was most prominent among students with menstrual migraine compared with students with menstrual nonmigraine headache (12.2% versus 2.7%). Exacerbation of migraine during menstruation was slightly more severe and more complex than exacerbation of nonmigraine headache. Female students with migraine versus nonmigraine headache did not differ significantly in age, age at onset of menarche, or age at onset of headache. Female students with migraine were significantly more likely to report a positive family history for migraine and menstrual migraine, severe attacks, reduced work activity, and aura.

CONCLUSION

The results obtained are in accord with the prevailing opinion that there is a relationship between migraine and female sex hormones, and suggest that women with nonmigraine headache are also susceptible to hormonal fluctuations.

CACNA1A gene polymorphisms in cluster headache

Cluster headache (CH) is a primary headache disorder where the aetiological and pathophysiological mechanisms still are largely unknown. An increased risk of CH in first- and second-degree relatives suggests the importance of genetic factors. Mutations of the P/Q type calcium channel alpha 1 subunit (CACNA1A) gene on chromosome 19p13 have been shown to cause several neurological disorders with a wide clinical spectrum, mainly episodic diseases. Missense mutations of the gene cause familial hemiplegic migraine (FHM) and it is also likely to be involved in the more common forms of migraine. The CACNA1A gene is thus a promising candidate gene for CH. In this study we performed an association analysis of an intragenic polymorphic (CA)n-repeat with marker D19S1150 and a (CAG)n-repeat in the 3'UTR region, in 75 patients with CH according to IHS criteria and 108 matched controls. Genotypes and allele frequencies were similarly distributed in patients and controls. Linkage disequilibrium between the two markers was similar in patients and controls. We conclude that an importance of the CACNA1A gene in sporadic CH is unlikely.

Contingent negative variation in subjects at risk for migraine without aura

Migraine is a complex disease with a significant genetic background. One possible strategy to investigate the genetics of migraine is the evaluation of functional vulnerability markers or biological elementary endophenotypes in individuals with the greatest probability of developing the disorder (high-risk design). In this study the contingent negative variation (CNV) was recorded in 35 high-risk subjects with a positive family history of migraine without aura (FHP), 35 low-risk individuals without a positive family history (FHN), and 35 migraineurs (migraine without aura). FHP subjects and migraine patients differed significantly from FHN individuals with regard to amplitude and habituation slope of the early CNV component (initial CNV or iCNV). FHP participants demonstrated the same iCNV abnormalities and distribution among iCNV characteristics as migraineurs. The amplitude of the iCNV correlated significantly with the relative number of subjects suffering from migraine among first- and second-degree relatives. The higher the density of affected individuals in the family, the more pronounced were the CNV abnormalities in relatives. This study provides evidence that the familial factor contributes to the abnormal amplitude, and to a lesser degree, habituation of the iCNV, and that the iCNV may be used as a functional-genetic vulnerability marker in further research of migraine genetics.

Familial migraine with and without aura: clinical characteristics and co-occurrence

Migraine with aura (MwA) and migraine without aura (MwoA) are the two common forms of migraine. Many migraine patients suffer from both kinds of attacks. In a questionnaire-based study using the current International Headache Society (IHS) criteria we determined the clinical characteristics and occurrence of MwA + MwoA in 1000 migraine patients belonging to 210 Finnish migraine families. Nine hundred and six patients were able to indicate whether they suffered from MwA (but not MwoA), migraine aura without headache (migraine equivalent) (but not MwA) or MwA and MwoA. Of these patients, 3.2% had experienced MwoA, 11.1% MwA, 40.6% MwA + MwoA, 23.5% MwoA and 20.3% MwA-like symptoms not meeting the IHS criteria. The high prevalence of MwA attacks in the families studied supports the belief that aura has a strong hereditary component. The MwA + MwoA patients had significantly more severe attacks, more typical headache and more prodromal symptoms than the MwA and MwoA subjects. Therefore, it is possible that there is a continuum with pure MwA at the neural and pure MwoA at the headache end of the spectrum, and MwA + MwoA lying in between the two. The MwA + MwoA patients would thus be liable to both types of migraine, making their attacks more characteristic and more severe. This would also explain why the co-occurrence of MwA and MwoA is more common in the clinic compared with population based epidemiological studies. These findings have consequences for future research on liability genes for migraine.

History of headache research in Denmark

Headache research in Denmark started with the description in 1949 by Dalsgaard-Nielsen of the percutaneous nitroglycerin test. In 1976 Jes Olesen started The Copenhagen Acute Headache Clinic and from that time modern headache research began in Denmark. Specific changes in regional cerebral blood flow during attacks of migraine with aura, spreading oligaemia, were described for the first time in 1980. The first headache classification with operational diagnostic criteria was published in 1988 and used in a Danish population study from 1989. The lifetime prevalence of migraine was 8% in men and 25% in women. An intravenous nitroglycerin test was introduced in 1989 and has been developed as an experimental headache model. In 1993 it was suggested by Jes Olesen et al. that NO supersensitivity could be a possible molecular mechanism of migraine pain. Recent genetic studies have supported the distinction between migraine with aura and migraine without aura. From the middle of the 1980s the pathophysiology of tension-type headache has been investigated and recent results indicate central sensitization in patients with chronic tension-type headache.

Treatment and management of cluster headache

Cluster headache is an uncommon yet well-defined neurovascular syndrome occurring in both episodic and chronic varieties. The most striking feature of cluster headache is the unmistakable circadian and circannual periodicity. Inheritance may play a role in some families. The attacks are of extreme intensity, of short duration, occur unilaterally, and are accompanied by signs and symptoms of autonomic dysfunction. In contrast to migraine, during an attack the cluster patient prefers to pace about. Attacks frequently occur at night. Although the pathophysiology of cluster headache remains to be fully elucidated, several seminal observations have recently been made. The medical treatment of cluster headache includes both acute therapy aimed at aborting individual attacks and prophylactic therapy aimed at preventing recurrent attacks during the cluster period. Agents used for acute therapy include inhalation of oxygen, sumatriptan, and dihydroergotamine. Transitional prophylaxis involves the short-term use of either corticosteroids or ergotamine derivatives. The cornerstone of maintenance prophylaxis is verapamil, yet methysergide, lithium, and divalproex sodium may also be employed. In some patients, melatonin or topiramate may be useful adjunctive therapies.

Validation of a migraine-specific questionnaire for use in family studies

The availability of valid migraine-specific questionnaires is important when large numbers of migraine patients have to be analysed. The Finnish Migraine-Specific Questionnaire has been validated in two stages. In the first, a clinical diagnosis of migraine was reached, using International Headache Society criteria, in 100 consecutive patients. Migraine was then diagnosed independently on the basis of responses to the Finnish Migraine-Specific Questionnaire. In the second stage, responses to 100 questionnaires returned consecutively in a family study in progress were analysed, and respondents were contacted by telephone for interview and diagnosis of migraine. Contact proved impossible in six cases. The sensitivity of the questionnaire for migraine was 0.99 (167 out of 168; validation stages 1 and 2 combined) and specificity was 0.96 (25 out of 26 cases; validation stage 2). It also proved possible to differentiate between migraine with and without aura on the basis of responses to the Finnish Migraine-Specific Questionnaire: chance-corrected agreement (Cohen's kappa) was 0.804 in relation to diagnoses reached on the basis of responses to the Finnish Migraine-Specific Questionnaire and clinically was 0.858 in relation to diagnoses reached on the basis of responses to the Finnish Migraine-Specific Questionnaire combined with the results of the telephone interviews. A value for Cohen's kappa > 0.75 indicates good agreement. Therefore, use of the Finnish Migraine-Specific Questionnaire in research into migraine genetics is justified.

Cluster headache

Cluster headache is a stereotypic, primary headache disorder that is marked by repeated short-lasting attacks of severe, unilateral head pain and associated autonomic symptoms. Cluster headache is probably due to an abnormality in the circadian hypothalamic generator with subsequent trigeminovascular activation. We have reviewed the clinical manifestations, pathophysiology, gender differences, and treatment options in cluster headache.

Dopamine and migraine: does Parkinson's disease modify migraine course?

As brainstem mechanisms and dopaminergic neurotransmission are involved in migraine pathophysiology, we decided to investigate the course of migraine in Parkinson's disease (PD), the paradigm of brainstem dopaminergic disease. We screened 237 consecutive PD out-patients by direct interview to assess the prevalence of lifetime and current migraine. Moreover, we compared the course of migraine in PD patients with that of otherwise healthy age- (+/- 3 years) and sex-paired migraine controls in a cross-sectional study. PD patients showed a lifetime migraine prevalence of 27.8% and a current migraine prevalence of 13.1%. A positive family history of migraine was less frequent in PD patients than in controls. The frequency of current migraine was significantly lower in PD patients than in controls (47.0% vs. 68.2%; odds ratio = 0.41, 95% confidence interval = 0.19-0.89). Approximately two-thirds of PD patients reported an improvement in or remission of migraine after PD onset. Effects of menopause on migraine course were similar in patients and controls. These findings suggest that PD might somehow shorten the clinical course of migraine. Possible explanations include a prolonged prophylactic effect by chronic dopaminergic therapy or a positive effect of PD pathophysiology, namely nigral degeneration, on migraine mechanisms.

Clinical characteristics of migraine concordant monozygotic twin pairs

OBJECTIVES

The aim of the study was to search for clinical differences between migraine with and without aura.

MATERIALS AND METHODS

From a population-based Finnish Twin Cohort we studied 51 migraine concordant monozygotic twin pairs.

RESULTS

There were 20 pairs concordant for migraine with aura, 6 pairs concordant for migraine without aura and 12 "mixed" pairs. In the remaining 13 pairs the aura of at least 1 twin could not be classified. All 20 migraine with aura pairs were concordant for visual aura and 19 for moderate or severe headache while all 6 pairs with migraine without aura were concordant for headache duration of 4 to 24 h, moderate or severe headache and nausea. The 12 "mixed" pairs had more often unilateral and pulsating headache compared to both the migraine with or without aura pairs. Overall individual migraine with aura twins had more photophobia (P = 0.032) and the migraine without aura twins more nausea (P = 0.025).

CONCLUSIONS

The difference between migraine with and without aura is not explained entirely by genetical factors: 12 genetically identical twin pairs were discordant for the aura. The headache phase in migraine with and without aura is very similar, but not identical. Probably there are several and different liability loci for the migraine aura and the migraine headache. The distribution of these several loci along with acquired factors will decide whether the phenotype is migraine with or without aura.

Comorbidity of headache and depressive disorders

The goal of the present study was to investigate the clinical profile of patients with primary headache syndromes who also suffer from mood disorders. Four-hundred-and-seventy headache outpatients (170M, 300F) and 150 age- and sex-matched healthy subjects were screened using a specific questionnaire that included the Hamilton rating scales for anxiety and depression. The average scores of the Hamilton rating scales for anxiety and depression were significantly higher in headache sufferers (17.4 and 14.2, respectively) than in healthy people (6.8 and 5.7, respectively). The frequency of headache attacks, the history of headaches, and gender (women more than men) were correlated with the score of the Hamilton rating scale for both anxiety and depression. Sixteen headache patients (3.4%) achieved the DSM-IV criteria for major depression or dysthymia versus one among headache-free subjects (0.6%; OR 5.2). Patients suffering from drug-overuse and migraine with aura showed the higher odds ratios (35 and 17, respectively). These results suggest that those headache patients with long history and high frequency of headaches, or patients suffering from migraine with aura and drug-overuse might benefit from psychiatric evaluation.

Clinical characteristics of migraine in a population-based twin sample: similarities and differences between migraine with and without aura

OBJECTIVE

To look into clinical differences between migraine with and without aura in a population-based sample of migraineurs.

BACKGROUND

Migraine presents in two major forms, migraine with and migraine without aura. With the exception of the aura phase, the clinical characteristics of these entities are very similar. Despite this, however, the recent epidemiological data underline differences between migraine with and without aura. We tried to examine whether other features besides the aura differ between these two major forms of migraine.

METHODS

We studied 321 twins suffering from migraine with aura and 166 twins with migraine without aura from the population-based Finnish Twin Cohort. Migraine was diagnosed according to the criteria of the International Headache Society (IHS). Analysis was based on the combination of a mailed questionnaire and a telephone interview by a neurologist. Special attention was paid to differences between migraine with and without aura.

RESULTS

Some qualities of headaches differed between IHS defined migraine with and without aura. Unilateral headache (Chi-squared p = 0.039) and photophobia (Chi-squared p = 0.010) were more typical for migraine with aura, while nausea was more typical for migraine without aura (Chi-squared p = 0.002). Duration of headache in migraine without aura was also longer than in migraine with aura (Mann-Whitney U-test 0.007).

CONCLUSIONS

There are clinical differences between IHS defined migraine with and without aura; even the headache phase between the two entities differs. It is worthwhile distinguishing between them when looking for the elusive genes for these more common forms of migraine.