Hypsarhythmia-infantile spasms in near-drowning: clinical, EEG, CT scan and evoked potential studies.

A 13-month-old child developed hypsarhythmia-infantile spasms after nearly drowning. Serial EEG, multimodality evoked potential, and CT scan of the brain revealed hypsarhythmia, disruption of ascending and descending tracts rostral to the mesencephalon, and a fairly severe degree of dilation of the ventricular system and subarachnoid space. We speculate that deafferentiation of the cerebral cortex is critical in the genesis of the hypsarhythmic pattern.