[Cerebellar imitation synkineses].

Imitation synkineses had not been described in cerebellar ataxia and were not known in cerebellar experimental neurophysiology. We describe here imitation synkineses when alternate movements of foot or hand were performed, in 2 cases of pure genetic cerebellar ataxia. The phenomenon was observed in other types of cerebellar ataxia (8 cases of anterior lobe cortical atrophy, 2 cases of surgical injury of the vermis). More imitation synkineses occurred on the right side in right-handed subjects, suggesting that the cerebellum physiologically inhibits a contralateral transfer of the copy of the movement. This inhibition would be particularly effective on the dominant side.