Acute encephalopathy in familial hemiplegic migraine with ATP1A2 mutation

Abstract

Familial hemiplegic migraine is a rare subtype of migraine with aura which includes motor weakness. A 32-year-old woman with known familial hemiplegic migraine (point mutation in Exon 22 of the ATP1A2 gene) presented with an acute confusional state, after an initially typical migraine. On examination, she had fever (38°C), agitated, with a right hemiparesis and dysphasia. Electroencephalography showed slowing of α rhythm and continuous rhythmical δ activity in the left hemisphere. She recovered 48 h after the onset of encephalopathic episode. Electroencephalography after recovery showed resolution of the abnormal slowing of the α waveforms.

Figure 1

Patient's EEG during the acute confusional state. It shows left hemisphere low amplitude delta activity (0.5–1 Hz) with less prevalent α rhythm (8–10 Hz) on the left side. Continuous rhythmical δ activity (1–5 Hz) was observed over left hemisphere.

Figure 2

Patient's EEG after recovery, which shows normalisation of the focal slow wave activity with background dominated by well formed α rhythm (9 Hz) in a visually responsive symmetrically distribution.