[P3-184] A Case with Cerebellar Ataxia and Severe Recurrent Attacks of Hemiplegic Migraine Mimicking Acute Encephalopathy
Hemiplegic migraine is a rare form of migrainous condition that involves temporary weakness on one side of the body. The clinical spectrum varies from moderate headache with motor weakness to severe attacks, including headache, consciousness disturbance, hemiplegia, convulsion, and cerebellar signs associated with congenital cerebellar ataxia. We report a 14-year-old girl with delayed psychomotor development and recurrent severe attacks of hemiplegic migraine, accompanied by congenital cerebellar ataxia. At the age of 2.5 years, she had the first attack of vomiting on awakening followed by prolonged coma, fever, and hemilateral sustained dystonia. These symptoms remitted in a few days. She had the recurrent episodes, occasionally associated with hemilateral convulsion and status dystonicus. The four attacks were triggered by head traumas and the eight attacks were spontaneous. For the treatment of severe attacks, she required intensive care with barbiturate coma therapy under mechanical ventilation. Unilateral slowing of EEG activity and severely reduced brain perfusion of radio-isotope indicated dysfunction of the affected hemisphere during severe attacks. The treatment with a calcium antagonist, lomerizine, and acetazolamide resulted in reduced severity and frequency of the attack. Genetic studies demonstrated a heterozygous deletion of 3 base pairs causing loss of a phenylalanine residue at position 1502 in the CACNA1A gene. This mutation induces gain of function of the calcium channels that trigger the glutamate release (Segarra et. al., 2014). Neuronal hyper-excitability may cause cortical spreading depression that results severe brain dysfunction and reduced metabolism in the affected hemisphere.