A quantitative assessment of reinnervation in the polyneuropathies.

The severity of denervation and the extent of compensatory reinnervation in a number of neuromyopathies was investigated using our computer-assisted motor unit counting and subtraction techniques. Patients with the chronic neuropathies of diabetes mellitus, renal failure and alcoholism, the acute neuropathy of the Guillain-Barré syndrome, and the neuronopathies of motor neuron disease and Alzheimer's disease were studied. Reinnervation in the uremic and alcoholic neuropathies was poor, and considerably less than that found in diabetic neuropathy. In general, the neuronopathies showed better reinnervation than the chronic neuropathies. In the acute neuropathy of the Guillain-Barré syndrome, reinnervation continued over periods of up to 7 years from the onset of the illness. Within this group some patients showed poor reinnervation, whereas in others we found that all of the electrophysiological parameters studied returned to normal, with concomitant remodeling of previously large motor units to normal size as reinnervation progressed.