NEUROPHYSIOLOGIC EVALUATION OF LOWER MOTOR-NEURON DAMAGE IN TETRAPLEGIA

We quantitatively investigated the extent of damage to motor neurons i n tetraplegic subjects. Numbers of motor units in the patients were si gnificantly lower for thenar, wrist extensor, and biceps brachii as co mpared to controls. Reduction in counts occurred even when M-response amplitudes were normal. Standard electromyography suggested a surprisi ng frequency of lower motor neuron dysfunction below the level of inju ry. These results confirm previous reports and add data on motor units in the biceps brachii, (C) 1998 John Wiley & Sons, Inc.