The electroencephalogram in phenylpyruvic oligophrenia

Abstract

Electroencephalographic studies in the waking and sleeping state of 19 patients with phenylpyruvic amentia reveals that waking activity in these patients is usually abnormal; it is of high voltage, slightly fast, slightly slow, or a mixture of fast and slow; seizure discharges of the petit mal type are common. Eleven patients showed seizure activity in the waking state and 18 had seizure activity during sleep. Thus the electroencephalogram confirms the clinical observation that epileptic disorder is a common complication in phenylpyruvic amentia. The occurence of 3/sec. spike and wave discharges of the petit mal type in more than one-third of the present group of patients with phenylpyruvic amentia is noteworthy because this pattern is rare in other types of symptomatic epilepsy. It suggests that there is some causal relation between the metabolic disorder which is present in phenylpyruvic amentia and the wave and spike pattern. The most consitent abnormality was a lack of well formed sleep patterns. Biparietal humps and spindles were either absent or poorly developed. Sleep activity was profoundly disorganized. In two cases mitten patterns were present. These findings suggested a pathological process with a strong epileptic component, causing a profound disturbance of both cortical and thalamic function.