Abstracts

Rationale: Alternating hemiplegia of childhood (AHC) is a rare, progressive disorder that usually presents first in infancy. Episodes can be triggered by various events including cold exposure, excitement, and startle. These episodes tend to disappear during sleep and the EEG is noncontributory. In contrast, benign nocturnal alternating hemiplegia of childhood (BNAHC) is an entity consisting of recurrent episodes of hemiplegia out of sleep. Unlike AHC, is not progressive and patients tend to be developmentally normal. The EEG in BANHC demonstrates hemispheric slowing contralateral to the deficit. We present an interesting case of a significantly, globally developmentally delayed 3 year-old boy with recurrent alternating hemiplegia episodes out of sleep since 6 months of age. Methods: Case ReportResults: Our patient had undergone an extensive metabolic and genetic work-up, demonstrating normal chromosomes and karyotype, mitochondrial DNA, serum amino acids, urine organic acids, and coagulopathy studies. DNA testing for familial hemiplegic migraine types 1, 2 and 3 were negative. After multiple normal EEGs that failed to capture an event, his episodes were finally captured on long-term video EEG, and found to be associated with a contralateral hemispheric electrodecrement during stage 2-3 sleep. MRI with diffusion weighted imaging and MR angiogram performed immediately after resolution of the witnessed hemiplegic event, and subsequent normalization of the EEG, were normal.Conclusions: To the best of our knowledge, BANHC has not been reported in a developmentally delayed child. Furthermore, this case confirms the importance of long-term monitoring to capture hemiplegic spells where routine EEGs have not been helpful.