The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy

Giorgia Querin; Timothée Lenglet; Rabab Debs; Tanya Stojkovic; Anthony Behin; François Salachas; Nadine Le Forestier; Maria del Mar Amador; Lucette Lacomblez; Vincent Meininger; Gaelle Bruneteau; Pascal Laforêt; Sophie Blancho; Véronique Marchand-Pauvert; Peter Bede; Jean Yves Hogrel; Pierre François Pradat

doi:10.1016/j.clinph.2018.08.025

The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy

Giorgia Querin
, Timothée Lenglet
, Rabab Debs
, Tanya Stojkovic
, Anthony Behin
, François Salachas
, Nadine Le Forestier
, Maria del Mar Amador
, Lucette Lacomblez
, Vincent Meininger
, Gaelle Bruneteau
, Pascal Laforêt
, Sophie Blancho
, Véronique Marchand-Pauvert
, Peter Bede
, Jean Yves Hogrel
, Pierre François Pradat

School of Biomedical Sciences

Research output: Contribution to journal › Article › peer-review

41 Citations (Scopus)

Abstract

Objective: Objective of this study is the comprehensive characterisation of motor unit (MU) loss in type III and IV Spinal Muscular Atrophy (SMA) using motor unit number index (MUNIX), and evaluation of compensatory mechanisms based on MU size indices (MUSIX). Methods: Nineteen type III and IV SMA patients and 16 gender- and age-matched healthy controls were recruited. Neuromuscular performance was evaluated by muscle strength testing and functional scales. Compound motor action potential (CMAP), MUNIX and MUSIX were studied in the abductor pollicis brevis (APB), abductor digiti minimi (ADM), deltoid, tibialis anterior and trapezius muscles. A composite MUNIX score was also calculated. Results: SMA patients exhibited significantly reduced MUNIX values (p < 0.05) in all muscles, while MUSIX was increased, suggesting active re-innervation. Significant correlations were identified between MUNIX/MUSIX and muscle strength. Similarly, composite MUNIX scores correlated with disability scores. Interestingly, in SMA patients MUNIX was much lower in the ADM than in the ABP, a pattern which is distinctly different from that observed in Amyotrophic Lateral Sclerosis. Conclusions: MUNIX is a sensitive measure of MU loss in adult forms of SMA and correlates with disability. Significance: MUNIX evaluation is a promising candidate biomarker for longitudinal studies and pharmacological trials in adult SMA patients.

Original language	English
Pages (from-to)	2333-2340
Number of pages	8
Journal	Clinical Neurophysiology
Volume	129
Issue number	11
DOIs	https://doi.org/10.1016/j.clinph.2018.08.025
Publication status	Published (in print/issue) - 1 Nov 2018

Funding

This study was supported by the Association Française contre les Myopathies (AFM) and the Institut pour la Recherche sur la Moelle épinière et l'Encéphale (IRME). The research leading to these results has also received funding from the program “Investissements d’avenir” ANR-10-IAIHU-06. Dr. Giorgia Querin, Dr. Timothée Lenglet, Dr. Anthony Behin, Dr. Tanya Stojkovic, Dr. François Salachas, Dr. Nadine Le Forestier, Dr. Maria del Mar Amador, Dr. Rabab Debs, Dr. Lucette Lacomblez, Prof. Vincent Meininger, Dr. Gaelle Brunetau, Prof. Pascal Laforêt, Sophie Blancho, Dr. Véronique Marchand-Pauvert, Dr. Jean-Yves Hogrel and Dr. Pierre-François Pradat report no disclosures. Dr. Peter Bede is supported by the Health Research Board (HRB – Ireland; HRB EIA-2017-019), the Irish Institute of Clinical Neuroscience IICN – Novartis Ireland Research Grant, and the Iris O'Brien Foundation Ireland.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

Keywords

Biomarkers
Motor unit loss
MUNIX
MUSIX
SMA type III
SMA type IV

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10.1016/j.clinph.2018.08.025

Cite this

Querin, G., Lenglet, T., Debs, R., Stojkovic, T., Behin, A., Salachas, F., Le Forestier, N., Amador, M. D. M., Lacomblez, L., Meininger, V., Bruneteau, G., Laforêt, P., Blancho, S., Marchand-Pauvert, V., Bede, P., Hogrel, J. Y., & Pradat, P. F. (2018). The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy. Clinical Neurophysiology, 129(11), 2333-2340. https://doi.org/10.1016/j.clinph.2018.08.025

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title = "The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy",

abstract = "Objective: Objective of this study is the comprehensive characterisation of motor unit (MU) loss in type III and IV Spinal Muscular Atrophy (SMA) using motor unit number index (MUNIX), and evaluation of compensatory mechanisms based on MU size indices (MUSIX). Methods: Nineteen type III and IV SMA patients and 16 gender- and age-matched healthy controls were recruited. Neuromuscular performance was evaluated by muscle strength testing and functional scales. Compound motor action potential (CMAP), MUNIX and MUSIX were studied in the abductor pollicis brevis (APB), abductor digiti minimi (ADM), deltoid, tibialis anterior and trapezius muscles. A composite MUNIX score was also calculated. Results: SMA patients exhibited significantly reduced MUNIX values (p < 0.05) in all muscles, while MUSIX was increased, suggesting active re-innervation. Significant correlations were identified between MUNIX/MUSIX and muscle strength. Similarly, composite MUNIX scores correlated with disability scores. Interestingly, in SMA patients MUNIX was much lower in the ADM than in the ABP, a pattern which is distinctly different from that observed in Amyotrophic Lateral Sclerosis. Conclusions: MUNIX is a sensitive measure of MU loss in adult forms of SMA and correlates with disability. Significance: MUNIX evaluation is a promising candidate biomarker for longitudinal studies and pharmacological trials in adult SMA patients.",

keywords = "Biomarkers, Motor unit loss, MUNIX, MUSIX, SMA type III, SMA type IV",

author = "Giorgia Querin and Timoth{\'e}e Lenglet and Rabab Debs and Tanya Stojkovic and Anthony Behin and Fran{\c c}ois Salachas and \{Le Forestier\}, Nadine and Amador, \{Maria del Mar\} and Lucette Lacomblez and Vincent Meininger and Gaelle Bruneteau and Pascal Lafor{\^e}t and Sophie Blancho and V{\'e}ronique Marchand-Pauvert and Peter Bede and Hogrel, \{Jean Yves\} and Pradat, \{Pierre Fran{\c c}ois\}",

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Querin, G, Lenglet, T, Debs, R, Stojkovic, T, Behin, A, Salachas, F, Le Forestier, N, Amador, MDM, Lacomblez, L, Meininger, V, Bruneteau, G, Laforêt, P, Blancho, S, Marchand-Pauvert, V, Bede, P, Hogrel, JY & Pradat, PF 2018, 'The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy', Clinical Neurophysiology, vol. 129, no. 11, pp. 2333-2340. https://doi.org/10.1016/j.clinph.2018.08.025

TY - JOUR

T1 - The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy

AU - Querin, Giorgia

AU - Lenglet, Timothée

AU - Debs, Rabab

AU - Stojkovic, Tanya

AU - Behin, Anthony

AU - Salachas, François

AU - Le Forestier, Nadine

AU - Amador, Maria del Mar

AU - Lacomblez, Lucette

AU - Meininger, Vincent

AU - Bruneteau, Gaelle

AU - Laforêt, Pascal

AU - Blancho, Sophie

AU - Marchand-Pauvert, Véronique

AU - Bede, Peter

AU - Hogrel, Jean Yves

AU - Pradat, Pierre François

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Objective: Objective of this study is the comprehensive characterisation of motor unit (MU) loss in type III and IV Spinal Muscular Atrophy (SMA) using motor unit number index (MUNIX), and evaluation of compensatory mechanisms based on MU size indices (MUSIX). Methods: Nineteen type III and IV SMA patients and 16 gender- and age-matched healthy controls were recruited. Neuromuscular performance was evaluated by muscle strength testing and functional scales. Compound motor action potential (CMAP), MUNIX and MUSIX were studied in the abductor pollicis brevis (APB), abductor digiti minimi (ADM), deltoid, tibialis anterior and trapezius muscles. A composite MUNIX score was also calculated. Results: SMA patients exhibited significantly reduced MUNIX values (p < 0.05) in all muscles, while MUSIX was increased, suggesting active re-innervation. Significant correlations were identified between MUNIX/MUSIX and muscle strength. Similarly, composite MUNIX scores correlated with disability scores. Interestingly, in SMA patients MUNIX was much lower in the ADM than in the ABP, a pattern which is distinctly different from that observed in Amyotrophic Lateral Sclerosis. Conclusions: MUNIX is a sensitive measure of MU loss in adult forms of SMA and correlates with disability. Significance: MUNIX evaluation is a promising candidate biomarker for longitudinal studies and pharmacological trials in adult SMA patients.

AB - Objective: Objective of this study is the comprehensive characterisation of motor unit (MU) loss in type III and IV Spinal Muscular Atrophy (SMA) using motor unit number index (MUNIX), and evaluation of compensatory mechanisms based on MU size indices (MUSIX). Methods: Nineteen type III and IV SMA patients and 16 gender- and age-matched healthy controls were recruited. Neuromuscular performance was evaluated by muscle strength testing and functional scales. Compound motor action potential (CMAP), MUNIX and MUSIX were studied in the abductor pollicis brevis (APB), abductor digiti minimi (ADM), deltoid, tibialis anterior and trapezius muscles. A composite MUNIX score was also calculated. Results: SMA patients exhibited significantly reduced MUNIX values (p < 0.05) in all muscles, while MUSIX was increased, suggesting active re-innervation. Significant correlations were identified between MUNIX/MUSIX and muscle strength. Similarly, composite MUNIX scores correlated with disability scores. Interestingly, in SMA patients MUNIX was much lower in the ADM than in the ABP, a pattern which is distinctly different from that observed in Amyotrophic Lateral Sclerosis. Conclusions: MUNIX is a sensitive measure of MU loss in adult forms of SMA and correlates with disability. Significance: MUNIX evaluation is a promising candidate biomarker for longitudinal studies and pharmacological trials in adult SMA patients.

KW - Biomarkers

KW - Motor unit loss

KW - MUNIX

KW - MUSIX

KW - SMA type III

KW - SMA type IV

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DO - 10.1016/j.clinph.2018.08.025

M3 - Article

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AN - SCOPUS:85053813318

SN - 1388-2457

VL - 129

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EP - 2340

JO - Clinical Neurophysiology

JF - Clinical Neurophysiology

IS - 11

ER -

The motor unit number index (MUNIX) profile of patients with adult spinal muscular atrophy

Abstract

Funding

UN SDGs

Keywords

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