Alpha-pattern coma in a 2-year-old child

T. Yamada, N. Stevland and J. Kimura

An EEG of a two-year-old child with Reye's syndrome complicated by prolonged hypoglycemia showed continuous, diffusely distributed, 8- to 9-Hz, well-modulated alpha activity while the patient was comatose. Continuous monitoring of EEG showed gradual reduction of alpha activity and the appearance of moderate-amplitude delta waves within the next 18 hours. Subsequent EEGs showed electrocerebral silence. The EEG features and their evolution resembled those described in postanoxic "alpha-pattern coma" in adults. A diffuse cortical-subcortical insult, possibly due to hypoglycemia, may be responsible for the generation of diffuse alpha activity in our case. Because of its transient nature, immediate and serial EEG studies following the acute cerebral insult may be necessary to demonstrate this pattern in children.