Electrophysiologic changes in uremic neuropathy after successful renal transplantation.

The pattern of electrophysiologic abnormalities in uremic neuropathy was studied in 17 patients near the time of successful renal transplantation and for an average of 2 years (4 to 68 months) afterward. Initially, sensory and motor conduction velocities were reduced, distal latencies were lengthened, and evoked action potentials were reduced or dispersed. These abnormalities were most marked in clinically severe neuropathies and were consistent with the combined presence of axonal degeneration and segmental demyelination. Following transplantation, there was a sustained improvement in motor and sensory conduction velocities but less consistent improvement in evoked action potentials. In severe neuropathies, action potentials tended to remain reduced or absent. The results suggest that the main reason for improvement in the neuropathy is segmental remyelination, some fibers remaining degenerate in severe neuropathies. In four patients, late failure occurred in the transplanted kidney, which was accompanied by recurrence of neuropathy. In each patient, a second successful transplant effected improvement for a second time.