Original Article Electrophysiologic Study of Central Motor Pathways in Ataxia-Telangiectasia

To date, corticospinal tract functional integrity in ataxia-telangiectasia has not been studied. Thorough evaluation of cen-tral motor pathways is also lacking in neuropathologic and clinical studies. Using electromagnetic stimulation, we assessed the integrity of the corticospinal tracts in eight patients with ataxia-telangiectasia. Cortical and peripheral compound motor action potentials were recorded from the abductor pollicis brevis muscle. Recordings of the shortest F-wave latency and of the compound motor action potential distal latency were made from the abductor pollicis brevis muscle after electri-cal 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 clinical findings compatible with a pyramidal lesion. This study demonstrates involvement of the central motor pathways in ataxia-telangiectasia, which appears to be more frequent late in the course of the dis-ease. (J Child Neurol 1997;12:327-331). Ataxia-telangiectasia is an autosomal recessive disorder characterized by variable immunodeficiency,1 oculocuta-neous telangiectases and cerebellar ataxia. The ataxia-telangiectasia gene has been mapped to chromosome llq22-23. ~ Onset of the neurologic deficit typically occur