EPILEPSY AND THE ELECTROENCEPHALOGRAM IN PROGRESSIVE ENCEPHALOPATHY WITH EDEMA, HYPSARRHYTHMIA, AND OPTIC ATROPHY (THE PEHO SYNDROME)

Progressive encephalopathy with edema, hypsarrhythmia, and optic atrop hy (PEHO syndrome) is an apparently autosomal recessive disorder manif ested by infantile spasms, severe hypotonia, and early arrest of psych omotor development. Subcutaneous edema in the limbs, typical facial fe atures, and blindness with optic atrophy are also present. Neuropathol ogic and radiographic studies show progressive brain atrophy, which is accentuated infratentorially. We recorded 85 EEGs from 10 patients be tween the ages of 3 weeks and 12.7 years; follow-up ranged from 7 mont hs to 12.1 years. The infantile spasms were preceded by other neurolog ical symptoms in all patients. Seven of nine patients showed focal or generalized epileptiform activity or abnormal EEG background. All pati ents developed hypsarrhythmia, first recorded between 3 and 11 months of age, that was resistant to therapy with ACTH and antiepileptic drug s. After the hypsarrhythmia disappeared, five patients showed slow spi ke-wave activity generally seen in the Lennox-Gastaut syndrome, and th ree patients showed background EEG abnormality with generalized or dif fuse paroxysmal activity. There were no specific EEG features that cou ld help in the diagnosis of PEHO. The PEHO syndrome should be borne in mind in the diagnostic work-up of patients with infantile spasms, so that potentially harmful treatment can be avoided, and the parents can be counseled about the inheritability of the disorder.