Childhood disintegrative disorder: distinction from autistic disorder and predictors of outcome.

Childhood disintegrative disorder, a rare, relentlessly progressive neurologic disorder, first described by Heller in 1908, remains a condition of great interest. It has long been debated whether it is a discrete disorder or simply a late-onset variant of childhood autism. We have studied 6 cases of childhood disintegrative disorder, collected over 8 years, and followed for 2.5 to 22 years (mean 8.6 years). Childhood disintegrative disorder begins later in life than autism, and following a period of entirely normal development; the regression is more global and more severe than in autism; seizures are more frequent than in autism, yet demonstrable organicity in childhood disintegrative disorder is decidedly rare. Lastly, the prognosis is usually much worse than in autism, but in those cases with neither seizures nor epileptiform activity on electroencephalography (EEG), the outcome may be more favorable. Childhood disintegrative disorder should be viewed as a condition distinct from childhood autism.