F waves and condution velocities: normative data and reproductibility

BV UNIFESP: Teses e dissertaçõe

Reproducibility in nerve conduction studies and F-wave analysis

Objective: Reproducibility testing of nerve conduction studies and F-wave latencies in a group of healthy volunteers.Methods: A total of 32 healthy volunteers underwent sensory and motor nerve conduction studies of the ulnar and tibial nerves, including F-waves, elicited by 32 stimuli, repeated in two different days by the same examiner.Results: the F-wave latencies showed less variability than the other parameters of conduction studies, and, among them, the F-wave mean latency of the tibial nerve has been the one with the higher reproducibility.Conclusions: F-wave latencies were the parameters with best reproducibility, followed by conduction velocities and amplitudes.Significance: Our data showed that the F-wave mean latency is a parameter with a high reliability, considering the reproducibility, for sequential studies. (c) 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Universidade Federal de São Paulo, Dept Neurol & Neurosurg, Setor Pesquisa & Posgrad Neurofisiol Clin, SEPENC, BR-04002010 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurol & Neurosurg, Setor Pesquisa & Posgrad Neurofisiol Clin, SEPENC, BR-04002010 São Paulo, BrazilWeb of Scienc

MUNIX: Reproducibility and clinical correlations in Amyotrophic Lateral Sclerosis

Objective: To study the reproducibility, diagnostic yield to detect denervation, and clinical correlations of the Motor Unit Number Index (MUNIX) in subjects with Amyotrophic Lateral Sclerosis (ALS). Methods: MUNIX evaluation was performed in three muscles twice on the same day to assess reproducibility. Cut-off values for the MUNIX were based on data from 51 healthy subjects (controls) to evaluate the sensitivity of the technique to detect denervation in 30 subjects with ALS. Results: The method had good reproducibility. The variability was greater in the ALS group. In 23 ALS subjects (77%), low MUNIX values were detected. Most of the muscles with low MUNIX had also low compound muscle action potential (CMAP) and strength, but these parameters were normal in 9% of muscles. According to ROC curve analysis, MUNIX was generally accurate (AUC = 0.9504) for discriminating between healthy individuals and subjects with at least one denervated muscle. Conclusions: MUNIX variability was higher in the ALS group. The method showed good diagnostic performance for the detection of denervation in a sample of patients with ALS. Significance: This study demonstrated that in addition to being a quantitative tool MUNIX can detect denervation in subjects with ALS. (C) 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Univ Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilUniv Sao Paulo, Sch Med FMUSP, Div Mol Med, Dept Med, BR-05508 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilWeb of Scienc