Lithium and peripheral nervous system function in manic-depressive patients.
BACKGROUND
Lithium salts are widely used in treatment of affective disorders, but lithium may cause electrophysiologically detectable changes in peripheral nervous system even with lithium concentrations within recommended therapeutic limits. The risk of lithium treatment against other risks to peripheral nervous system in psychiatric patients with affective psychoses was tested in our study.


METHODS
Electrophysiologic parameters of motor and sensory peripheral nerve fibre function were measured in two age-matched groups of psychiatric patients (20 lithium-treated and 20 affective psychotic patients without lithium treatment) and a group of 20 healthy age-matched volunteers.


RESULTS
Lower amplitudes of M waves (p < 0.015) and sensory nerve action potentials (p < 0.020) on stimulation of the median nerve have been found in both groups of patients. On peroneal nerve stimulation lower M wave amplitudes have been found only in the group of lithium-treated patients (p < 0.055). No significant differences in conduction parameters of motor and sensory fibres were demonstrated.


CONCLUSIONS
Our results demonstrate subclinical involvement of motor and sensory axons in affective-psychotic patients, which is only slightly more pronounced in lithium-treated patients. We suggest that lithium (within therapeutic plasma concentrations) is just one among the factors leading towards minor axonopathy in psychiatric patients.
Podnar
S
S
Institute of Clinical Neurophysiology, University Medical Centre, Ljubljana, Slovenia.
Vodusek
D B
DB
Zvan
V
V
D000328:Adult; D001369:Axons / Q000187:drug effects; D001714:Bipolar Disorder / Q000188:drug therapy*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008094:Lithium / Q000009:adverse effects* / Q000627:therapeutic use*; D008297:Male; D008475:Median Nerve / Q000187:drug effects; D008875:Middle Aged; D009434:Neural Pathways / Q000187:drug effects; D017933:Peripheral Nervous System / Q000187:drug effects* / Q000503:physiopathology; D010543:Peroneal Nerve / Q000187:drug effects
D008094:Lithium