Walsh & Hoyt: Progressive Encephalopathy with Edema, Hypsarrhythmia, and Optic Atrophy (PEHO Syndrome)

Salonen et al. described 14 patients from 11 families with a progressive encephalopathy with onset in the first 6 months of life, followed by severe hypotonia, convulsions with hypsarrhythmia, profound mental deterioration, hyperreflexia, transient or persistent facial and body edema, and optic atrophy. Optic atrophy is usually noted by the first or second year of life, and nystagmus is common. Microcephaly and brainatrophy develop, especially inthe cerebellar and brain stem areas. A metabolic defect has yet to be determined, although elevations of nitric oxide have been noted, and an autosomal-recessive mode of inheritance is likely. This could be considered a form of Behrs syndrome, which probably represents a heterogeneous group of disorders.