Extrapyramidal side effects in lithium maintenance therapy.

The authors neurologically examined 36 patients who had been maintained on lithium therapy for periods ranging from 6 months to 7 years to determine the presence of parkinson-like side effects. Only a few patients demonstrated rigidity, including cogweel rigidity, and this was at a low level of severity. These results do not support the previously reported frequent occurrence of cogwheel rigidity in patients on lithium maintenance.