Davood Fathi1, Bahram Mohammadi2, Reinhard Dengler3, Sebastian Böselt3, Susanne Petri3, Katja Kollewe4. 1. Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran; International Neuroscience Institute, Hannover, Germany. 2. International Neuroscience Institute, Hannover, Germany; Department of Neurology, University of Lübeck, Lübeck, Germany. 3. Department of Neurology, Hannover Medical School, Hannover, Germany. 4. Department of Neurology, Hannover Medical School, Hannover, Germany. Electronic address: kollewe.katja@mh-hannover.de.
Abstract
OBJECTIVE: Motor unit number estimation (MUNE) techniques such as motor unit number index (MUNIX) have been used to quantify lower motor neuron loss and disease progression in amyotrophic lateral sclerosis (ALS). We investigated the consistency of reproducibility of MUNIX in 30 ALS-patients during the course of the disorder. METHODS: MUNIX was recorded in abductor pollicis brevis and tibialis anterior muscles bilaterally in ALS-patients by two measurements at the first and at one follow-up visit and once in healthy controls. Intra-rater reproducibility was evaluated by three statistical methods: interclass correlation coefficient (ICC), correlation coefficient analysis (CCA), and coefficient of variation (CV). RESULTS: We found significant correlation between the first and second measurement of MUNIX in all tested muscles and at the follow-up visit (r⩾0.891, p<0.01) and good statistically significant reproducibility of MUNIX in all four measured muscles at the follow-up visit (ICC⩾0.946, p<0.01). The CV of MUNIX at the follow-up visit ranged from 13.90% to 32.95%. CONCLUSIONS: This study shows good consistency of reproducibility of MUNIX in the course of ALS. SIGNIFICANCE: This study suggests that MUNIX can be used to track the progression of the disorder both in clinical routine and in treatment trials.
OBJECTIVE: Motor unit number estimation (MUNE) techniques such as motor unit number index (MUNIX) have been used to quantify lower motor neuron loss and disease progression in amyotrophic lateral sclerosis (ALS). We investigated the consistency of reproducibility of MUNIX in 30 ALS-patients during the course of the disorder. METHODS:MUNIX was recorded in abductor pollicis brevis and tibialis anterior muscles bilaterally in ALS-patients by two measurements at the first and at one follow-up visit and once in healthy controls. Intra-rater reproducibility was evaluated by three statistical methods: interclass correlation coefficient (ICC), correlation coefficient analysis (CCA), and coefficient of variation (CV). RESULTS: We found significant correlation between the first and second measurement of MUNIX in all tested muscles and at the follow-up visit (r⩾0.891, p<0.01) and good statistically significant reproducibility of MUNIX in all four measured muscles at the follow-up visit (ICC⩾0.946, p<0.01). The CV of MUNIX at the follow-up visit ranged from 13.90% to 32.95%. CONCLUSIONS: This study shows good consistency of reproducibility of MUNIX in the course of ALS. SIGNIFICANCE: This study suggests that MUNIX can be used to track the progression of the disorder both in clinical routine and in treatment trials.
Authors: Christoph Neuwirth; Christian Burkhardt; James Alix; José Castro; Mamede de Carvalho; Malgorzata Gawel; Stephan Goedee; Julian Grosskreutz; Timothée Lenglet; Cristina Moglia; Taha Omer; Maarten Schrooten; Markus Weber Journal: PLoS One Date: 2016-05-02 Impact factor: 3.240