Intellectual function in Duchenne muscular dystrophy: the influence of penicillamine.

No effect of penicillamine upon intelligence was found in boys with Duchenne muscular dystrophy when compared to placebo administered in a double-blind fashion. All children, however, showed a significant progressive decline in intelligence quotient. An analysis of mental age showed no change over a 24-month period, suggesting that a static intellectual deficit exists. These data support other findings of a central nervous system dysfunction in patients with Duchenne muscular dystrophy.