EVALUATION OF SOMATOSENSORY PATHWAY BY SHORT LATENCY EVOKED-POTENTIALS IN PATIENTS WITH END-STAGE RENAL-DISEASE MAINTAINED ON HEMODIALYSIS

The lncernational Journal Of Artificial Organs / Vol. 4 no. 1, 1981 I p.p. 17·22 C> by Wichcig Edilore srl, 1981 i Evaluation of somatosensory pathway by short latency evoked potentials in patients with end-stage renal disease maintained on hemodialysis D. Vaziri, H. Pratt, J.K. Saiki and A. Starr Division of Nephrology and Department of Neurology University of California Irvine, California, U.S.A. KEY W ORDS Somatosensory evoked potentials End-stage renal disease Maintenance hemodialysis Nerve end ing conduction defect ABSTRACT Somatosensory evoked potentials and peripheral nerve conduction velocity were studied on 10 patients with end-stage renal failure maintained on hemodialysis treatment. None of the patients had symptomatic neuropathy and the only abnormal finding on neurologi- cal examination was absent ankle jerk in 7 of the 1 O pa- tients. Nerve conduction velocities and intercomponent conduction times of the somatosensory evoked potential were determined using electrical stimulation of nerve trunks and mechanical stimulation of the finger. Nerve ending conduction time was determined using a combi- nation of the two stimuli and found to be abnormal in 8 patients. All 10 patients had slowed sensory conduction velocities at some segment of the tested peripheral nerve. lntercomponent time differences in the somatosensory evoked potentials could not be defined in the majority of our patients due to the absence of many of the components, making it impossible to distinguish whether the changes in somatosensory evoked potentials were due to impaired peripheral input, or to changes in the somatosensory pathway. Controversy exists regarding t he validity of nerve conduction velocity measurements in evaluation of peripheral nerve function in patients with end-stage renal failure. While high incidence of reduced nerve conduction velocity has been shown in these patients before and af- ter institution of maintenance dialysis (3-12). these parameters have been shown to be within the normal range in a more re cent investigation (13). Somatosensory potentials evoked by electrical stimu- lation of peripheral nerves have been increasingly used for indentification of neurologic disorders along the somatosensory pathway at peripheral nerves (14-21) as well as the central portions (22-36). More recently, proce- dures for recording of the mechanically-evoked potentials from different levels of the somatosensory pathway have been described (37) and compared with those evoked by electrical stimulation of the nerves (38). Utilizing somatosensory evoked potential studies it is possible to evaluate the function of various levels of sen- sory pathway. Furthermore, evaluation of the nerve en- ding may be po:;sible with a combination of mechanical- ly- and electrically-evoked potentials studies (38). In the .. present study, potentials evoked by electrical and mecfi': f&cal stimulation w ere studied in evaluation of peripheral and central somatosensory pathway in 1 O pa- tients treated with maintenance hemodialysis. Clinical evaluations and conventional motor nerve conduction velocity studies were performed as well. PATIENTS, MATERIALS AND METHODS Pati ents INTRODUCTION Peripheral neuropathy is the most common neurological complication of chronic renal failure (1 ). It was described by Asbury, et al as a distal, symmetrical, mixed sensorimotor polyneuropathy (2). M otor and sen- sory nerve conduction velocities, distal latency, and re- sponse amplitude determinations have been used in the assessment of uremic neuropathy and adequacy of dialysis. n Ten patients with end-stage renal disease maintained on hemodialysis treatment were studied. i:-here were 6 men and 4 women, 24 to 67 years of age. Duration on dialysis ranged between 1 to 74 months. Patients were dialyzed 4 hours a day and 3 days a week using single pass dialysate delivery system, hollow fiber dialyzers with 1.2·2.5 m 2 surface area, and a glucose-free, acetate- based dialysate. Internal vascular access consisting of Cimino arteriovenous fistulas, polyfluorotetraethylene