SENSORY AND MOTOR CONDUCTION IN MOTOR NEURONE DISEASE

Abstract

Conduction in sensory and motor fibers and in the mixed median nerve was examined in 15 patients with motor neuron disease (8 with mainly bulbo-spinal, 4 with spinal and 3 with mainly bulbar involvement). In addition, motor conduction velocity was determined in 10 patients with sequelae after acute anterior poliomyelitis. The temperature near the nerve was kept at 34-35[degree]C. The sensory conduction velocity between fingers and wrist and between wrist, elbow and axilla was normal as were amplitude, shape and duration of the sensory potentials. The velocity of mixed median nerve between wrist, elbow and axilla was as the velocity of the sensory fibers. The distal motor latency and the motor conduction between elbow and wrist were slightly below the velocity of the sensory fibers but within the range of normal, whether or not the response amplitude was severely reduced. The motor conduction velocity between axilla and elbow was slightly lower than in normals (0.001 < p < 0.01). In the 10 patients with sequelae after acute anterior poliomyelitis the conduction velocity was normal in the median and peroneal nerves, as were the distal motor latencies, the latency to the anterior tibial muscles and the amplitude of the muscle action potentials.