Lateralization of neuroleptic-induced dyskinesia indicates pharmacologic asymmetry in the brain.

Since the two hemispheres of the human brain are asymmetrical for various cognitive and perceptual functions, a pharmacological as well as the known anatomical differentiation between the two hemispheres may underly the asymmetrical functions. A lateralization of the dyskinetic states consequent to long-term usage of large doses of neuroleptics would be indicative of a pharmacologic asymmetry in the brain hemispheres. Seven of eight right-handed psychiatric patients had greater right-than left-sided dyskinesias, a finding which pointed to pharmacological vulnerability in the left dominant hemisphere.