Subclinical lithium neurotoxicity: correlation of neural conduction abnormalities and serum lithium level in manic-depressive patients with lithium treatment.

Nerve conduction velocities (NCVs) and multimodality evoked potentials were studies in 28 manic-depressive patients under lithium prophylaxis with serum lithium levels between 0.320 and 0.980 mEq/L. Slowing of motor and sensory NCVs and prolonged central neural conduction times obtained from somatosensory and brainstem auditory evoked potentials were found to correlate with serum lithium levels. Lithium-induced changes in cell membrane conductivity and in the synaptic transmission are considered responsible for the neurotoxic effects of lithium.