Hemiplegic Migraine: Clinical Features, Links with Basilar-type Migraine, Current and Future Treatment

Abstract

Hemiplegic migraine (HM) is a rare variety of migraine with aura characterized by the presence of a motor weakness during the aura. The HM has two main forms according to the familial history: cases where at least one first- or second-degree relative has aura including motor weakness have familial hemiplegic migraine (FHM), and cases without such familial history have sporadic hemiplegic migraine (SHM). FHM is the only variety of autosomal dominant migraine and all three known genes encode ion-transporters. Typical HM attacks include a motor weakness that is always associated to other aura symptoms, the most frequent being sensory, visual, and speech disturbances. In addition, basilar-type symptoms occur in up to 70% of the patients. Severe attacks may occur in FHM as well as in SHM with prolonged hemiplegia, confusion, coma, fever, and seizures. The clinical spectrum also includes permanent cerebellar signs (nystagmus, ataxia, dysarthria) and less frequently various types of seizures and mental retardation. A genetic diagnosis is now possible by screening the two major genes involved in FHM (CACNA1A and ATP1A2). Treatment of FHM and SHM is based on what is done in other varieties of migraine with aura. According to the new physiopathologic insights, preventive treatments by various antiepileptic agents seem promising.