Implementing Motor Unit Number Index (MUNIX) in a large clinical trial: Real world experience from 27 centres

Publication

Implementing Motor Unit Number Index (MUNIX) in a large clinical trial: Real world experience from 27 centres

Journal Paper/Review - May 3, 2018

Neuwirth Christoph, Finegan Eoin, Glass Jonathan D, Babu Suma, Ladha Shafeeq S, Kwast-Rabben Olga, Juntas-Morales Raul, Coffey Amina, Chaudhry Vinay, Vu Tuan, Saephanh Chow, Newhard Colleen, Zakrzewski Marion, Rosier Esther, Hamel Nancy, Raheja Divisha, Raaijman Jesper, Ferguson Toby, Tümmler Anke, Appelfeller Martin, Braun Nathalie, Claeys Kristl G, Bucelli Robert, Fournier Christina, Bromberg Mark, Petri Susanne, Goedee Stephan, Lenglet Timothée, Leppanen Ron, Canosa Antonio, Goodman Ira, Al-Lozi Muhammad, Ohkubo Takuya, Hübers Annemarie, Atassi Nazem, Abrahao Agessandro, Funke Andreas, Weber Markus

Citation

Neuwirth C, Finegan E, Glass J, Babu S, Ladha S, Kwast-Rabben O, Juntas-Morales R, Coffey A, Chaudhry V, Vu T, Saephanh C, Newhard C, Zakrzewski M, Rosier E, Hamel N, Raheja D, Raaijman J, Ferguson T, Tümmler A, Appelfeller M, Braun N, Claeys K, Bucelli R, Fournier C, Bromberg M, Petri S, Goedee S, Lenglet T, Leppanen R, Canosa A, Goodman I, Al-Lozi M, Ohkubo T, Hübers A, Atassi N, Abrahao A, Funke A, Weber M. Implementing Motor Unit Number Index (MUNIX) in a large clinical trial: Real world experience from 27 centres. Clin Neurophysiol 2018; 129:1756-1762.

Type

Journal Paper/Review (English)

Journal

Clin Neurophysiol 2018; 129

Publication Date

May 3, 2018

Issn Electronic

1872-8952

Pages

1756-1762

Brief description/objective

OBJECTIVE
Motor Unit Number Index (MUNIX) is a quantitative neurophysiological method that reflects loss of motor neurons in Amyotrophic Lateral Sclerosis (ALS) in longitudinal studies. It has been utilized in one natural history ALS study and one drug trial (Biogen USA) after training and qualification of raters.

METHODS
Prior to testing patients, evaluators had to submit test-retest data of 4 healthy volunteers. Twenty-seven centres with 36 raters measured MUNIX in 4 sets of 6 different muscles twice. Coefficient of variation of all measurements had to be <20% to pass the qualification process. MUNIX COV of the first attempt, number of repeated measurements and muscle specific COV were evaluated.

RESULTS
COV varied considerably between raters. Mean COV of all raters at the first measurements was 12.9% ± 13.5 (median 8.7%). Need of repetitions ranged from 0 to 43 (mean 10.7 ± 9.1, median 8). Biceps and first dorsal interosseus muscles showed highest repetition rates. MUNIX variability correlated considerably with variability of compound muscle action potential.

CONCLUSION
MUNIX revealed generally good reliability, but was rater dependent and ongoing support for raters was needed.

SIGNIFICANCE
MUNIX can be implemented in large clinical trials as an outcome measure after training and a qualification process.