Tibial nerve H-reflex and F-wave studies in patients with uremic neuropathy

The nerve conduction velocity along the whole length (knee to the spinal cord) of the 1a sensory and motor fibers of the tibial nerve, innervating the gastrocnemius and soleus muscles, of 29 control subjects and 32 patients with chronic renal failure was estimated with recently introduced electrophysiologic F-wave and H-reflex methods. In control subjects and in uremic patients, the proximal sensory (1a) nerve conduction veloctiy (SNCV) was faster than the proximal motor nerve conduction velocity (MNCV), a finding which is attributed to the larger diameter and therefore faster conduction properties of 1a fibers. In uremic patients, the proximal 1a SNCV and MNCV were significantly slowed in comparison with the values in control subjects, while the terminal M-response latency was not significantly prolonged.