[Medullar and supraspinal conduction in multiple sclerosis: localization value (author's transl)].

Spinal cord and central conduction velocities were studied in 12 patients with multiple sclerosis and in 20 healthy volunteers using an indirect method (Dorfman's) that includes the determination of the somatosensory evoked potentials by median and posterior tibial nerves stimulation, latency of the F-waves and motor and sensory conduction velocities in the wrist-elbow segment of the median nerve. Patients with symptoms and signs of demyelination showed very altered conductions in both of the segments studied, but five patients without clinical suspicion of sensory alteration showed normal spinal cord and supraspinal conduction time just in the limit of normality. The physiopathologic aspects of the demyelination lesions in the central nervous system that determine a block in the condution are discussed.