Migraine aura or transient ischemic attacks? A five-year follow-up case-control study of women with transient central nervous system disorders in pregnancy

BACKGROUND Migraine aura may be difficult to differentiate from transient ischemic attacks and other transient neurological disorders in pregnant women. The aims of the present study were to investigate and diagnose all pregnant women with transient neurological disorders of suspected central nervous system origin, and to compare this group with a control group of pregnant women with regard to vascular risk factors and prognosis. METHODS During a 28 month period, 41 patients were detected with transient neurological symptoms during pregnancy. These were studied in detail with thorough clinical and laboratory investigations in order to make a certain diagnosis and to evaluate whether the episodes might be of a vascular nature. For comparison, the same investigations were performed in 41 pregnant controls. To assess the prognosis, both patients and controls were followed with questionnaires every year for five years. RESULTS Migraine with aura was the most common cause of symptoms during pregnancy, occurring in 34 patients, while 2 were diagnosed with stroke, 2 with carpal tunnel syndrome, 1 with partial epilepsy, 1 with multiple sclerosis and 1 with presyncope. Patients had more headache before pregnancy than controls, but the average levels of vascular risk factors were similar. None of the patients or the controls reported cerebrovascular episodes during the five-year follow-up. CONCLUSION The diagnosis of migraine aura was difficult because for many patients it was their first ever attack and headache tended to be absent or of non-migraineous type. The aura features were more complex, with several aura symptoms and a higher prevalence of sensory and dysphasic aura than usual. Gradually developing aura symptoms, or different aura symptoms occurring in succession as described in the International Classification of Headache Disorders, seem to be useful for differentiating aura from other transient disorders. A meticulous history and clinical neurological examination are more useful than routine supplementary investigations for cerebrovascular disease. The five-year follow-up clearly indicates that migraine with aura in pregnancy usually has a good prognosis with regard to cerebrovascular events.