Persistent dysarthria with apraxia associated with a combination of lithium carbonate and haloperidol

Reported is a 19-year-old manic-depressive patient who developed persistent dysarthria with coexisting apraxia while on a combination of high dose haloperidol and lithium carbonate. The speech disability occurred as a solitary symptom in a patient with normal serum lithium levels and no other signs or symptoms of lithium toxicity and persisted after lithium was discontinued and the neuroleptic changed. There were several factors which favored an association between the speech disability and the drug therapy. These included improvement during a drug-free trial: the absence of a prior history of a speech problem; the patient's marked psychotic state and anxiety: and the high dosage of haloperidol.