CENTRAL MOTOR CONDUCTION TIME BY MAGNETIC STIMULATION OF THE CORTEX AND PERIPHERAL-NERVE CONDUCTION FOLLOW-UP-STUDIES IN FRIEDREICHS ATAXIA

A follow-up clinical study, peripheral motor and sensory nerve conduct ion velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained uncha nged for several years. Central motor conduction times were abnormal i n all patients. Clinical conditions worsened significantly between suc cessive examinations with significant increments in threshold and sign ificant decrement of the amplitude of motor evoked potentials. The res ults are consistent with progressive pyramidal and cerebellar pathways involvement as the cause of clinical worsening in FA. (C) 1997 Elsevi er Science ireland Ltd.