Mb Russell

Migraine without aura and migraine with aura are distinct clinical entities: a study of four hundred and eighty‐four male and female migraineurs from the general population

The clinical characteristics of migraine without aura (MO) and migraine with aura (MA) were compared in 484 migraineurs from the general population. We used the criteria of the International Headache Society. The lifetime prevalence of MO was 14.7% with a M:F ratio of 1:2.2; that of MA was 7.9% with a M:F ratio of 1:1.5. The female preponderance was significant in both MO and MA. The female preponderance was present in all age groups in MA, but was first apparent after menarche in MO, suggesting that female hormones are an initiating factor in MO, but not likely so in MA. The age at onset of MO followed a normal distribution, whereas the age at onset of MA was bimodally distributed, which could be explained by a composition of two normal distributions. The estimated separation between the two groups of MA was at age 26 years among the females and age 31 years among the males. The observed number of persons with co-occurrence of MO and MA was not significantly different from the expected number. The specificity and importance of premonitory symptoms are questioned, but prospective studies are needed. Bright light was a precipitating factor in MA, but not in MO. Menstruation was a precipitating factor in MO, but not likely in MA. Both MO and MA improved during pregnancy. The clinical differences indicate that MO and MA are distinct entities.

Evidence of a genetic factor in migraine with aura: A population‐based Danish twin study

We studied the genetic influence on cause of migraine with aura (MA) by analyzing a twin population. The twin sample consisted of 2,026 monozygotic (MZ) twins and 3,334 same‐sex dizygotic (DZ) twins, born from 1953 to 1960, from the population‐based New Danish Twin Register. A validated questionnaire was used to screen for migraine, the response rate being 87%, and similar among MZ and DZ twins. All twin pairs with at least 1 twin with possible MA were interviewed by a physician experienced in headache diagnoses. The answers from the questionnaire as well as the zygosity of the twins were blinded for the interviewer. A total of 211 twin pairs were identified, of whom 77 pairs were MZ and 134 pairs were DZ. The lifetime prevalence of MA was 7% and with a male‐to‐female ratio of 1:1.1. The pairwise concordance rates were significantly higher in MZ (34%) than in DZ twin pairs (12%), emphasizing the importance of genetic factors in MA. However, environmental factors are also important, as the pairwise concordance rate was less than 100% in MZ twin pairs. The recurrence risk of MA was 50% in MZ and 21% in DZ twin pairs. In nontwin siblings, the recurrence risk of MA is 27%, which is similar to the recurrence risk in DZ twins. This indicates that MA is not developed due to specific environmental factors shared by the twins. Ann Neurol 1999;45:242–246

Migraine without aura: a population-based twin study.

To investigate the importance of genetic and environmental factors to the etiology of migraine without aura and to compare the symptomatology of migraine without aura in monozygotic and dizygotic twins, 2,680 twin pairs were recruited from the population‐based Danish Twin Registry. Monozygotic (MZ) and same‐sex dizygotic (DZ) twin pairs, where at least one twin had self‐reported migraine or self‐reported severe headache with accompanying symptoms, were telephone interviewed by a physician. The participation rate in the telephone interview was 90%. The pairwise concordance rate was significantly higher in MZ than in DZ twin pairs (28% vs 18%). The probandwise concordance rate was 40% (95% CI, 33–48%) in MZ and 28% (95% CI, 23–33%) in DZ twin pairs. The pairwise concordance rates for the different pain characteristics and accompanying symptoms were not significantly different in MZ and DZ twin pairs. However, comparing all of the pairwise concordance rates of pain characteristics and accompanying symptoms together, MZ twin pairs were significantly more concordant than DZ twin pairs. Our data demonstrate a significant genetic factor in migraine without aura. The size of this factor is modest and the demonstration of susceptibility genes is predicted to be laborious and difficult.

A comparison of tension-type headache in migraineurs and in non-migraineurs: a population-based study

&NA; The prevalence, sex‐ratio and clinical characteristics of tension‐type headache were analyzed in 4000 people from the general population. The one‐year‐period prevalence of tension‐type headache was not significantly different in people with migraine without aura (83%), in people with migraine with aura (75%) and in people who had never had migraine (76%). The male/female ratio varied from 1:1.19 to 1:1.23 and was not significantly different in the three subgroups. Tension‐type headache was significantly more frequent within the last year and lasted longer in migraineurs than in people who had never had migraine. The pain characteristics and accompanying symptoms were very similar in the three subgroups. Tension‐type headache was often precipitated by stress, mental tension and tiredness. Only migraineurs had episodes of tension‐type headache precipitated by alcohol, over‐matured cheese, chocolate and physical activity. We conclude that tension‐type headache and migraine are separate disorders and not part of a continuum of headache disorders. However, migraine may aggravate and precipitate tension‐type headache possibly due to convergence of various noxious peripheral input into the trigeminal nucleus.

Migraine without aura and migraine with aura are inherited disorders.

The familial occurrence and mode of inheritance were analysed in families with migraine without aura (MO) and migraine with aura (MA). The probands were found among 4000 persons from the general population. All persons with MA were included as probands, and an equivalent number of probands with MO was selected as a random sample among those with MO. Spouses and first-degree relatives were blindly interviewed. All interviews were performed by one neurological research fellow. The distinct familial patterns indicate that MO and MA have a different aetiology. Compared with the general population, the first-degree relatives of probands with MO had a 1.9-fold increased risk of MO while spouses had a 1.5-fold increased risk of MO, indicating that both genetic and environmental factors are important in MO. The first-degree relatives of probands with MA had a four-fold increased risk of MA while spouses had no increased risk of MA, indicating that MA is determined largely by genetic factors. The complex segregation analysis indicate that both MO and MA have multifactorial inheritance without generational difference.

SCREENING FOR MIGRAINE IN THE GENERAL POPULATION : VALIDATION OF A SIMPLE QUESTIONNAIRE

We present validation of a simple questionnaire designed to screen the general population for migraine. It comprises four questions: (1) “Have you ever had migraine?” (2) “Have you ever had severe headache accompanied by nausea?” (3) “Have you ever had severe headache accompanied by hypersensitivity to sound and light?” (4) “Have you ever had visual disturbances lasting 5–60 min followed by headache?” A telephone interview carried out by a physician was used as an index of validity. The study population was 5,360 twins from the population-based Danish Twin Registry. All twin pairs where at least one twin had answered “yes” to at least one of our questions were eligible for the telephone interview (n=2,272 twins). The response rate to the questionnaire was 87%; the participation rate in the telephone interview was 90%. The questionnaire ascertained 85% of all migraineurs (sensitivity). A combination of two questions (questions 1 and 4) extracted 93% of the twins with migraine with aura and 74% of the twins with migraine without aura, yet only 26% of the sample needed to be interviewed. We conclude that in the Danish population two simple questions are sufficient to screen for migraine in selecting participants for a diagnostic clinical interview. Our questionnaire clearly merits further study to document its universal applicability.

Inheritance of migraine investigated by complex segregation analysis

Migraine is the most common neurological disorder, affecting about 20% of adults. The mode of inheritance was analyzed in the two main types of migraine, migraine without aura (MO) and migraine with aura (MA), by complex segregation analysis using the computer program POINTER. We included 126 probands with MO and 127 probands with MA from the general population. Firstdegree relatives and spouses were blindly interviewed by a neurological research fellow. The complex segregation analysis indicated that both MO and MA have multifactorial inheritance without generational difference.

Altered allelic distributions of the serotonin transporter gene in migraine without aura and migraine with aura

Allelic variation of the human serotonin transporter gene (HSERT), a highly plausible candidate gene for susceptibility to migraine, was investigated in 266 individuals with migraine, including 173 having migraine without aura (MO), 94 having migraine with aura (MA), 18 with co-occurrence of MO and MA, plus 133 unaffected controls. The distribution of a polymorphism with different forms of a variable tandem number repeat (VNTR) in intron 2 were compared. The MO group had an over-representation of genotypes with two twelve repeat alleles (STin2.12) and a reduction of genotypes containing one ten repeat (STin2.10) compared to controls. The MA group showed a similar pattern, but also a trend towards an increase in genotypes containing the nine repeat allele of the VNTR (STin2.9). Genotypes containing this allele were found in 6.4% of the MA group compared to 2.3% of controls. The group with co-occurrence of MO and MA had a significantly different pattern of overall allele frequency distribution from controls, reflecting a reduction in genotypes containing the STin2.10 allele and a shift both to STin2.9 carriers and to STin2.12 homozygosity. These results support the view that susceptibility to MO and MA has a genetic component, that these disorders are distinct, and that genetic susceptibility may in some cases be associated with a locus at or near the serotonin transporter gene.

Improved Description of the Migraine Aura by a Diagnostic Aura Diary

We present a diagnostic aura diary for prospective recordings of migraine with aura. Three questionnaires are supplemented with sheets for drawings and plottings of visual and sensory auras. Twenty patients recorded 54 attacks of migraine with aura and 2 attacks of migraine aura without headache. The visual and sensory aura were usually gradually progressive, reaching maximum development in 15 and 25 min (median) respectively and had a total duration of 20 and 55 min (median) respectively. Approximately 13% of the attacks had acute onset of visual aura associated with other features more typical of migraine. The visual and sensory auras always preceded typical migraine headache, and headache occurring before aura symptoms was always of the tension type, The migraine headache was milder than in attacks of migraine without aura and often did not have migraine characteristics. In attacks with unilateral head pain, headache and aura symptoms were contralateral in 90% and ipsilateral in 10%.

Migraine without aura and migraine with aura are distinct disorders. A population-based twin survey.

Objective.—To investigate the co‐occurrence of migraine without aura (MWOA) and migraine with aura (MWA) in a population‐based twin survey.