[Lithium and cerebral functions].

Two cases, sustaining the possible part of long term lithium therapy in progressive intellectual deterioration, are submitted. Arguments clinic as well as paraclinical and fundamental, supporting the idea of insidious lithium's neurotoxicity are discussed. Most recent findings about drug's incidence on the cerebral functioning are reviewed. The study of the erythroplasmatic ratio and the analysis of several factors implied in its variations seem to back up our hypothesis.