Case study: corticosteroid treatment of language regression in pervasive developmental disorder.

The authors describe a child whose language and behavior regressed at 22 months and in whom pervasive developmental disorder was later diagnosed. At 6 years, he displayed a profound receptive-expressive aphasia accompanied by behavioral disturbances characterized by hyperactivity, impaired social interactions, tantrums, gestural stereotypies, and echolalia. A single-photon emission computed tomography scan and steady-state auditory evoked potentials suggested bitemporal and left frontal pathophysiology. The overall profile resembled Landau-Kleffner syndrome, but no electroencephalographic disturbance was evident. Corticosteroid treatment resulted in amelioration of language abilities and behavior. These findings suggest that the factors underlying language regression in pervasive developmental disorder can, in special circumstances, be amenable to pharmacological treatment.