ELECTROPHYSIOLOGIC STUDY OF CENTRAL MOTOR PATHWAYS IN ATAXIA-TELANGIECTASIA

To date, corticospinal tract functional integrity in ataxia-telangiect asia has not been studied. Thorough evaluation of central motor pathwa ys is also lacking in neuropathologic and clinical studies. Using elec tromagnetic stimulation, we assessed the integrity of the corticospina l tracts in eight patients with ataxia-telangiectasia. Cortical and pe ripheral compound motor action potentials were recorded hom the abduct or pollicis brevis muscle. Recordings of the shortest F-wave latency a nd of the compound motor action potential distal latency were made fro m the abductor pollicis brevis muscle after electrical stimulation of the median nerve at the wrist. A significant increase in central motor conduction time was observed in four patients, two of whom had clinic al findings compatible with a pyramidal lesion. This study demonstrate s involvement of the central motor pathways in ataxia-telangiectasia, which appears to be more frequent late in the course of the disease.