An Unusual Presentation of Sporadic Hemiplegic Migraine: A Case Report

Sporadic Hemiplegic Migraine (SHM) is a rare subtype of migraine with recurrent attacks of reversible motor weakness alongside with visual, sensory and speech symptoms. It is classified as familial when a first- or second- degree relative has identical motor attack, and as sporadic when no such relative is affected. Patients with this subtype have been found to have a mutation in either CACNA1A, ATP1A2 or SCN1A. In present case, a 13-year-old male, first born to a third degree consanguineous couple presented to the emergency department with severe headache lasting for an hour following which there was weakness in the right upper and lower limbs, blurring of vision in the left eye and deviation of angle of mouth to left followed by tonic movements of both upper limbs which lasted for five minutes. Child had frequent headaches for last six months and there was family history of migraine without motor involvement in mother and maternal grandmother. He was initially considered to have Transient Ischaemic Attack (TIA)/stroke. However, after initial stabilisation there was a dramatic neurological improvement within an hour of presentation hence the possibility of Hemiplegic Migraine (HM) was considered. Genetic testing was positive for CACNA1A mutation and hence the diagnosis of SHM was confirmed. The child was treated with Calcium Channel Blockers (CCB) and was put on aspirin prophylaxis. The child had no further episodes of hemiplegia post treatment, although there had been episodes of headaches with reduced intensity and duration. Parents were counselled regarding the possible prognosis and importance of follow-up for early identification of cerebellar signs and paroxysmal manifestations. Genetic counselling is recommended for future prenatal planning.