Electroencephalographic findings in children with moyamoya disease.

The EEG findings in 25 children with moyamoya disease were studied. Characteristic findings such as posterior slow, centrotemporal slow (CT slow), "rebuildup" after the end of hyperventilation, and sleep spindle depression were observed. Posterior slow activity was mainly observed in the EEGs examined within a short period (mean, 10 months) after onset, CI slow activity after a longer period (mean,, 28 months), and a diffuse low-voltage pattern after these periods (mean, 56 months). Buildup after the end of hyperventilation, which we refer to as "rebuildup," was discovered in more than half of the cases.