CEREBELLAR HYPERMETRIA ASSOCIATED WITH A SELECTIVE DECREASE IN THE RATE OF RISE OF ANTAGONIST ACTIVITY

Classically, cerebellar hypermetria observed during fast and accurate movements is ascribed to a delayed onset of the electromyographic acti vity of the antagonist muscle. We describe here 3 patients presenting a late-onset cerebellar degeneration and exhibiting a hypermetria duri ng their fast and accurate movements in spice of a normal onset latenc y of the antagonist activity. Hypermetria was found to be due to a slo wer rate of rise of the antagonist activity.