Carpal tunnel syndrome, subclinical median mononeuropathy, and peripheral polyneuropathy: common early complications of chronic peritoneal dialysis and hemodialysis.

Nerve conduction velocity studies were done in median, ulnar, and peroneal nerves, one time each in 46 patients who had been on chronic peritoneal dialysis or hemodialysis for varying lengths of time. Only six patients had normal findings; 37 had peripheral polyneuropathy (15 had isolated polyneuropathy; 22 had median nerve dysfunction in addition); 16 had subclinical median mononeuropathy (14 with polyneuropathy, two without); and nine had overt carpal tunnel syndrome (eight with polyneuropathy, one without). Abnormalities were present in seven of the 11 patients studied after one year of dialysis and in 19 of the 24 patients studied after two years of dialysis. Seventeen patients studied after five years of dialysis all had polyneuropathy. Nine patients studied after seven years of dialysis all had median nerve dysfunction. Abnormalities were as common with peritoneal dialysis as with hemodialysis. Nerve dysfunction was independent of the disease underlying renal failure, the side of the dialysis access shunt, and the presence or absence of osteodystrophy. Dialysis patients need frequent nerve conduction studies from the onset of dialysis to identify carpal tunnel syndrome early and to avoid irreversible nerve damage.