OBJECTIVETo summarize the clinical characteristics of alternating hemiplegia of childhood (AHC).

METHODSThe clinical data of 13 children with AHC were analyzed. Cranial MRI, EEG, analysis of serum amino acids and urinary organic acids, measurement of plasma lactate and pyruvate levels were done in all patients. Other laboratory examinations such as magnetic resonance angio-imaging (MRA), digital subtraction arteriography (DSA) and Video-EEG were also performed in some patients.

RESULTSOf the 13 patients, 12 were male, and 1 was female. The age of onset was from 2 days to 55 months (average 13.1 months). The initial symptoms were abnormal ocular movements (AOMs) consisting of ocular deviation, gaze or nystagmus in 2 cases, AOMs and dystonic posturing in 9 cases, hemiplegia in 2 cases. All patients had recurrent alternating hemiplegic episodes. The hemiplegic attacks lasted from a few minutes to 10 days. The occurrence of the attacks ranged from 8 times daily to one time every 2 months. In 10 patients the abnormal eye movements or dystonic posturing, at times, recurred intermittently during the hemiplegic attack. Choreoathetosis was present in 2 cases. Ataxia was present in 1 case; 7 patients also had the episodes of quadriplegia. During the episodes of quadriplegia, dysarthria or aphasia was present in 4 cases, dyspnea and dysphagia was present in 2 cases, respectively. Sleep could relieve both weakness and associated paroxysmal symptoms. Mental retardation was present in 9 cases, seizures in 3 cases. Except for EEG or Video-EEG was abnormal in 3 patients, other laboratory investigations were normal in all patients. Twelve patients received flunarizine therapy. Flunarizine reduced the severity, duration, or frequency of hemiplegic attacks in 8 patients.

CONCLUSIONThe results suggest that AHC is characterized by frequent episodes of alternating hemiplegia with extrapyramidal symptoms and mental retardation, flunarizine is effective in treating some AHC patients.