Reversible memory disturbance and intelligence impairment induced by long-term anticholinergic therapy.

It is controversial whether long-term anticholinergic therapy (AC-T) can cause short-term memory disturbance, long-term memory disturbance or intelligence impairment. Ninety patients with Parkinson's disease were examined prospectively to clarify the existence of memory and intelligence impairment induced by long-term AC-T. Neuropsychological tests detected eight patients with at least one of four types of deficits; intelligence impairment in four patients, verbal delayed recall impairment in eight, verbal short-term memory disturbance in five, and verbal long-term memory disturbance in six. Two types of verbal memory disturbance (short-term one and long-term one) appeared with double dissociation, suggesting that there may be an independence between the two types of verbal memory system. Older patients were more prone to suffer from these reversible deficits. Moreover, all of the patients who resumed AC-T, showed recurrence of the deficits acutely. These observations should indicate the tight relation between long-term AC-T and neuropsychological deficits.