Profound encephalopathy with complete recovery in three children with familial hemiplegic migraine

We describe three cousins who presented with agitation, dysphasia and/or coma, and developed hemiplegia following initial onset of symptoms. Two cases followed minor head injuries, two were pyrexial and two were associated with neutrophilia. Two cases required ventilatory support on the intensive care unit. Magnetic resonance imaging in all three cases showed cortical swelling, and one had evidence of restricted water diffusion on diffusion-weighted imaging, suggestive of ischaemia/infarction. A complete family history at the time of presentation would have led to an earlier diagnosis of profound encephalopathy in familial hemiplegic migraine, which would have enabled better prognostication of their clinical course and caused less distress for the families.