Early Treatment in Acute Severe Encephalopathy Caused by ATP1A2 Mutation of Familial Hemiplegic Migraine Type 2: Case Report and Literature Review

Familial hemiplegic migraine type 2 (FHM2) is an autosomal dominant inheritance disorder caused by ATP1A2 mutation, and the clinical spectrum is heterogeneous even with acute severe encephalopathy. However, up to now, early treatments against acute and severe attacks in FHM2 are still insufficient. Here, we report a 15-year-old female with intellectual disability due to FHM2 caused by a pathogenic ATP1A2 gene mutation, presenting mild-to-moderate headache at the onset, followed by confusion, complete right hemiparalysis, epileptic partial seizures, and conscious disturbance with rapid progression in acute attack. Brain magnetic resonance imaging (MRI) and magnetic resonance spectroscopy have revealed left extensive cerebral cortex edema, slightly decreased N-acetylaspartate for neuronal damage, and mildly increased lactate acid for mitochondrial dysfunction throughout the hemispheric swollen cortex. The patient is diagnosed as severe encephalopathy caused by FHM2. Based on literature review about pathophysiologic mechanism described in FHM2 recently, we use early treatments including prevention of glutamatergic excitotoxicity and protection of mitochondria function, as well as traditional antimigraine drug. The symptoms are all greatly improved and recovered within a short time, and follow-up MRI also shows complete disappearance of edema throughout the left hemispheric cortex. Altogether, the approach in our case may reduce the severity and duration of encephalopathy effectively, expend therapeutic options, and provide helpful references for acute severe encephalopathy in FHM2.