Possible lithium-induced extrapyramidal effects in Alzheimer's disease.

Extrapyramidal symptomatology has previously been reported in patients on long-term lithium maintenance. This report emphasizes that, in the presence of organic mental disorder, even brief treatment with lithium may induce severe extrapyramidal signs. Furthermore, toxicity to lithium may occur even though serum lithium levels are at therapeutic levels. Following termination of lithium, symptoms subsided quickly in one patient (five days), but more slowly in the other (16 days). Possible pathophysiology of this phenomenon is discussed.