The application of F wave measurements in hepatic patients

The ulnar and tibial nerve F response latencies were analyzed to study the proximal motor conduction velocity in 15 patients with liver disease. The results were compared with those obtained from 15 normal subjects. The tibial MNCV (P less than 0.01) and FWCV from spinal cord to elbow and knee for ulnar and tibial nerves (P less than 0.001) were significantly reduced in patients compared to the controls. Minimum, mean and maximum F latencies showed significant differences for ulnar (P less than 0.001) and tibial (P less than 0.01) nerves in patients with respect to the controls. The mean F determination compared to the minimum F and delta F did not improve disease identification. The conduction abnormality in hepatic patients appeared to be present only in the proximal segment of the ulnar nerve, whereas it was more uniformly distributed along the entire length of the tibial nerve. This demonstrates that the peripheral nerve involvement in hepatic disease is more diffusely present than can be determined by conventional conduction study only.