Page 63 - Migraine, the heart and the brain

Covariates and definitions.
Sociodemographic and medical history characteristics were assessed by telephone interview.3 Cardiovascularriskdiagnoseswerebasedonpatientreportofaphysician’s diagnosis.3 In women, postmenopausal state was de ned as last menstruation at least 3 months previously or a history of ovariectomy.
Statistical analysis. 3 Differences in the distributions and means of characteristics among the study
groups were tested with x2, 2-tailed Fisher exact, unpaired t, and MannWhitney
U test when appropriate. The presence of ongoing migraine attack recurrence
was examined by RLS diagnosis (yes/no) using a model adjusting for age, sex, and postmenopausalstate.Likewise,usinglogisticregression,theriskofMRIoutcomes was examined by RLS diagnosis (yes/ no) and migraine and age as covariates.
Based on findings in previous studies, we decided beforehand to conduct 3 specific analyses. First, because an increased prevalence of RLS had only been found for migraine with aura,4,6 we analyzed the prevalence of RLS separately for migraine with and without aura. To detect a difference of 20% in RLS frequency with a power of 0.8 and a set at 0.05, we would need 162 participants (total number in 2 arms). Second, because silent infarcts were found increased only in the posterior cerebral circulation,2 we analyzed their presence separately for this part of the circulation. Finally, because higher prevalence of deep white matter lesions was only found in women with migraine,3 we conducted this analysis stratified forsex.Allperformedstatisticaltestsareshownintextortables;reportedpvalues are not corrected for multiple testing as this study was an exploratory hypothesis- generating study rather than confirmatory research. Data were analyzed using Statistical Software Package for Social Sciences (SPSS version 20.0; IBM, Armonk, NY).
results
Clinical and demographic data of the participants are summarized in table 1. Except for diabetes, there were no differences between migraineurs and controls in age, sex, or cardiovascular history.
Table 2 summarizes the prevalence of RLS among the various study groups. Of the migraineurs with aura, 60% had RLS vs 42% of controls (unadjusted odds ratio [OR]
Right-to-left shunts and migraine
61