Autonomic system dysfunction and polyneuropathy in nondiabetic uremia. A one-year follow-up study after renal transplantation.

Polyneuropathy and autonomic dysfunction were studied in 15 patients with nondiabetic terminal uremia before renal transplantation and again at 6 and 12 months after the transplantation. Beat-to-beat variation of the electrocardiogram (ECG) relative to mean beat interval was used as an observation of the function of the parasympathetic vagal reflex arc. Marked autonomic dysfunction--i.e., reduced beat-to-beat variation and a mild diffuse polyneuropathy--was found. The neuropathy was mainly of axonal type, but a slowing of conduction velocities was also found. The latter was markedly improved after transplantation and is suggested to be caused by a toxic metabolic factor, possibly causing nodal dysfunction. Action potential amplitudes and autonomic function did not improve during the study. This implies a structural damage that is not repaired in 12 months. Neurological examination should be included in the care of patients with uremia, and the results should be one of the factors considered when transplantation is discussed.