ASYMMETRIC CHANGES IN SOMATOSENSORY-EVOKED POTENTIALS CORRELATE WITH LIMB APRAXIA IN CORTICOBASAL DEGENERATION

To clarify the underlying mechanism of limb apraxia in corticobasal de generation (CBD), we investigated somatosensory evoked potentials in 5 patients with CBD, as compared with 12 age-matched control subjects. All patients presented with asymmetric limb apraxia, particularly of l imb-kinetic type. N20 latencies were significantly prolonged following median nerve stimulation on the more apraxic side, but not on the les s apraxic side. These results suggest that limb apraxia in CBD may, at least in part, be due to a disorder of somatosensory information proc essing involving the parietal cortex. (C) Munksgaard 1998.