[Distal latency in motor neuron disease]

In our investigation 24 patients suffering from spinal amyotrophy and 11 from amyotrophic lateral sclerosis were analyzed in order to determine the influence of these diseases on teh conduction velocity of the distal motor and sensory fibers. Both diseases belong to motor neuron diseases and are of unknown etiology. The conduction velocity was measured by using electroneurographic methods. Distal motor latency is expressed as a quotient of terminal latency that is obtained by dividing the distance between the stimulation and the registration point by the latency of response and was measured in cm/ms. It represents the conduction velocity of the distal motor fibers. Its sensory equivalent is the sensory conduction velocity S0-S1. In our work the mean values of distal motor and sensory latencies were counted and the correlation between them was examined. We also counted the percentage of the patients with the pathological values of these parameters. The results indicate that the "motor neurone disease" affects the conduction velocity of the distal motor and sensory fibers. The distal sensory latency was prolonged in higher percentage than the motor latency. Between motor and sensory latencies no correlation was found.