West syndrome and Lennox-Gastaut syndrome: a survey of natural history.

The West syndrome and the Lennox-Gastaut syndrome are characterized by their onset in infancy and early childhood, intractable seizures occurring almost daily, severe psychomotor retardation, and poor prognosis. Among handicapped children, they offer the most serious problems in daily care at home or in institutions because of frequent attacks and marked retardation. A nationwide survey in Japan was performed to elucidate the natural history of these two syndromes.