Global motor unit number index sum score for assessing the loss of lower motor neurons in amyotrophic lateral sclerosis.
We propose a motor unit number index (MUNIX) global sum score in amyotrophic lateral sclerosis (ALS) to estimate the loss of functional motor units.



MUNIX was assessed for 18 ALS patients and 17 healthy controls in 7 muscles: the abductor pollicis brevis (APB), abductor digiti minimi (ADM), tibialis anterior (TA), deltoid, trapezius, submental complex, and orbicularis oris.



MUNIX was significantly lower in ALS patients than in healthy controls for the APB, ADM, TA, and trapezius muscles. The MUNIX sum score of 4 muscles (ADM + APB + trapezius + TA) was lower in ALS patients (P = 0.01) and was correlated with clinical scores.



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.
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.
Stephan
S
Grimaldi
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.
Lauréline
L
Duprat
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.
Aude-Marie
AM
Grapperon
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.
Annie
A
Verschueren
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.
Emilien
E
Delmont
Reference Center for Neuromuscular Diseases and ALS, APHM, University Hospital of Marseille/Timone University Hospital, 264 rue Saint Pierre, 13005, Marseille, France.|Aix Marseille University, INSERM, GMGF, Marseille, France.
Shahram
S
Attarian
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology*; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology*; D012720:Severity of Illness Index
ALS; MUNIX; biomarker; clinical correlation; global MUNIX sum score; motor unit