Carpal tunnel syndrome: a complication of arteriovenous fistula in hemodialysis patients S. Kumar,* md; H.L. TRiVEDi,t mb, frcp[c]; E.K.M. SMITH4 MD,
Summary: Symptoms of compression of the median nerve in the carpal tunnel developed in two patients in
whom an arteriovenous fistula was created to alleviate chronic renal failure through hemodialysis. Anatomic changes in the wrist area due to the fistula are probably important in the development of this syndrome, and pre-existing uremic peripheral polyneuropathy may also be important in the early development of local symptoms of nerve damage. Resume: Le
syndrome du tunnel
carpien: complication d'une fistule
arterioveineuse chez les malades soumis a I'hemodialyse
Des symptdmes de compression du nerf median dans le tunnel carpien ont apparu chez deux malades ou on avait du creer une fistule arterioveineuse pour attenuer une insuffisance renale chronique par I'hemodialyse. II est fort probable que les modifications anatomiques dans la region du poignet sont importants dans I'apparition de ce syndrome. Du reste, une polyneuropathie
MRCP
hemodialysis after 3 years in chronic renal failure. An AV fistula was formed by joining the radial artery to an adjacent vein about 2.5 cm proximal to the distal end of the radius8 in her left arm. She was
right-handed.
Intermittent tingling and numbness in her left thumb and left index and middle fingers developed 19 months later; the symptoms were much worse in the early morning and were partially relieved by elevating or shaking the arm. The left hand, especially the wrist (circumference at lower ends of radius and ulna, 17.2 cm) and thumb (circumference at root, 8.0 cm), was enlarged and swollen and larger than the right (wrist circumference at lower ends of radius and ulna, 16.6 cm; thumb circumference at root, 7.3 cm) (Fig. 1). Results of neurologic examina¬ tion, including assessment of motor and sensory function of the left hand, were normal. A radiograph of the left hand showed no bony changes. Nerve conduc¬ tion studies confirmed compression of the
peripherique uremique pre-existante
peut egalement etre importante dans le developpement precoce des symptdmes locaux de la lesion nerveuse.
Several complications of arteriovenous (AV) fistulas created for patients be¬
ginning long-term hemodialysis are well known,1"6 but the carpal tunnel syndrome has only been described once.7 Changes in the structures in the wrist area may lead to compression of the median nerve in the carpel tunnel. We report two such cases of carpal tunnel syndrome in patients undergoing long-term hemodialysis.
(LOND), frcp[c] median nerve in the left hand (Tables I and II). Resection of the carpal ligament in the tunnel relieved the paresthesias, though the swelling and enlargement per¬ sisted for 5 months after the operation. No abnormalities in the appearance of the median nerve were noted by the surgeon. Patient 2 A 48-year-old man, also with analgesic nephropathy, had rapid progression of chronic renal failure, such that long-term hemodialysis was begun 9 months after
the condition was detected. An AV fistula was created in his left arm at the same site as the fistula of patient 1. He was also right-handed. Tingling and numbness in the left thumb and left index and middle fingers, in the distribution of the median nerve, developed after 3 years. It was worse dur¬ ing the night and was relieved by shaking the arm and elevating the hand on pillows. Results of neurologic examination, including evaluation of motor and sensory function of the left hand, were normal. Radiologic examination of the cervical spine did not reveal any abnormality. The left hand was not enlarged; the only ab¬ normality was a prominent, pulsatile AV fistula extending beyond the wrist joint. Nerve conduction studies (Tables I and II) confirmed, by the criteria of O'Duffy, Randall and MacCarty,9 that the median nerve was compressed in the carpal tun¬ nel. The patient was treated conservatively with night splints, with some relief. Nerve conduction and
FIG. 1.Enlarged left thumb of 1 (who was right-handed).
patient
electromyographic
studies Both patients had the following evid¬ ence, from nerve conduction studies (Tables I and II), of compression of the
Case reports Patient 1 A 53-year-old woman with nephropathy due to analgesic abuse began long-term From the department of medicine, McMaster University, St. Joseph's Hospital, Hamilton, Ont. Patient ?Fellow in nephrology no. tAssistant professor of medicine of medicine ^Associate professor Reprint requests to: Dr. E.K.M. Smith, McMaster Medical Unit, St. Joseph's Hospital, Hamilton, ON L8N 1Y4 1070 CMA JOURNAL/DECEMBER 13, 1975/VOL. 113
Sensory nerve conduction velocity (m/s) For thumb For ring finger