Acquired transient CNS hypersensitivity to lithium therapy.

Organic brain syndrome is reported to occur occasionally in patients who are treated with lithium carbonate alone, or in combination with neuroleptics. Such neurotoxicity is often associated with moderate to low serum lithium levels and is usually reversible upon the cessation of lithium treatment. The authors report on a 57 year old manic-depressive and alcoholic patient who, after four years of lithium treatment, developed symptoms of CNS hypersensitivity which reappeared several times when he was challenged with lithium during a two month period. The possible role of an underlying, subclinical encephalopathy, caused by episodic drinking, is considered.