Global motor unit number index sum score for assessing the loss of lower motor neurons in amyotrophic lateral sclerosis

Abstract

The global MUNIX sum score proposed in this study estimates the loss of lower motor neurons in several body regions, including the trapezius, and is correlated with clinical impairment in ALS patients. Muscle Nerve 56: 202-206, 2017.

Modified motor unit number index (MUNIX) algorithm for assessing excitability of alpha motor neuron in spasticity

“…However, in these studies, motor unit loss and reinnervation have been evaluated in terms of being indicative. The upper motor neuron involvement has not been assessed in these studies ( Escorcio-Bezerra et al, 2016 , Fukada et al, 2016 , Grimaldi et al, 2017 , Neuwirth et al, 2017 ).…”

Combinatory Biomarker Use of Cortical Thickness, MUNIX, and ALSFRS-R at Baseline and in Longitudinal Courses of Individual Patients With Amyotrophic Lateral Sclerosis

“…As the acquisition of MUNIX is easier and less time consuming than that of MUNE, MUNIX has become a promising biomarker of motor unit loss ( 27 , 28 ). MUNIX scores were correlated with ALSFRS-R scores ( 26 ), but they declined faster than ALSFRS-R scores over time in ALS patients ( 29 ). Only few studies investigated the relationship between neurophysiological biomarkers and cortical thickness and failed to find a significant correlation with MUNE or other motor evoked potential indices ( 21 , 30 ).…”

“…MUNE is calculated from the division of maximal compound muscle action potential (CMAP) by the mean surface single motor unit action potential (SMUP) ( 25 ). In contrast, MUNIX is derived from a mathematical model based on CMAP and electromyographic surface interference patterns (SIP) ( 26 ). MUNE and MUNIX scores are inter-correlated in ALS patients ( 23 ).…”

The canaries in the coal mine: mune and munix in amyotrophic lateral sclerosis

“…[4][5][6] In this month's issue of the journal, Grimaldi and colleagues propose and test a MUNIX sum score, which incorporates MUNIX taken from multiple bulbar and extremity muscles, in both ALS subjects and controls. 7 Their sum score was significantly lower in the ALS group, and correlated significantly with concurrent clinical measures. However, MUNIX of the facial muscles themselves did not differ from controls, likely due to the challenges of obtaining highly reproducible CMAPs from these muscles.…”

“…MUNIX has the advantage of being easy to learn and perform, but uses special software in its current incarnation; it is reproducible, correlates well with relevant clinical measures, detects early denervation, and demonstrates decline over time in ALS . In this month's issue of the journal, Grimaldi and colleagues propose and test a MUNIX sum score, which incorporates MUNIX taken from multiple bulbar and extremity muscles, in both ALS subjects and controls . Their sum score was significantly lower in the ALS group, and correlated significantly with concurrent clinical measures.…”