PEHO syndrome (progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy): neuroradiologic findings.

PURPOSE To investigate the radiologic characteristics of the clinical progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) symptom complex. This complex is nonspecific, but within this syndrome, a subgroup with a defined neuropathologic phenotype and apparently autosomal recessive inheritance exists. METHODS Brain CT or MR studies were performed on 21 patients with the clinical PEHO syndrome. Their previous neuroradiologic studies were re-evaluated. RESULTS Twelve patients (group A) showed uniform changes with early progressive brain atrophy accentuated infratentorially, and abnormal myelination. The gyral pattern was normal. Brain atrophy of nine patients (group B) differed by being less progressive, supra- rather than infratentorial, and often combined with abnormal gyral formation. CONCLUSIONS Postmortem studies permitted correlation of radiographic and morphologic findings in three cases. Two autopsied group A patients were compatible with the true PEHO syndrome, while one group B patient was incompatible. Group A seems to correspond to the core group of the PEHO syndrome. During a patient's life, a suggestive diagnosis of the true PEHO syndrome is thus feasible, although neuropathologic studies are needed for a conclusive diagnosis.