Action Potentials; Adult; Aged; Amyotrophic Lateral Sclerosis/diagnosis/physiopathology; Electric Stimulation; Female; Humans; Longitudinal Studies; Male; Middle Aged; Motor Neurons; Muscle, Skeletal/innervation/physiopathology; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Thumb/physiopathology
Abstract :
[en] METHOD: The adapted multiple point stimulation (AMPS) method for calculating motor unit numbers (MUNE) was applied in 12 patients with amyotrophic lateral sclerosis (ALS) before riluzole therapy (T(0)) and again after 4, 8 and 12 months of treatment. RESULTS: Paired Student's t-test indicated a significant decrease of thenar MUNE and compound muscle action potential (CMAP) size at each 4-monthly interval, while average surface motor unit potential (SMUP) size did not change significantly over time. The rate of motor unit (MU) loss at month 4 was more than 20% in six patients (group 1) and less than 20% in six other patients (group 2). Comparison of groups 1 and 2 by Mann-Whitney U-testing indicated that percent changes in thenar MUNE and CMAP size compared to baseline were significantly different at months 4, 8 and 12, while no difference between the two groups was found for average SMUP size variations. In the group with a slow rate of MU loss, CMAP size remained stable, while in the group with a rapid rate of MU loss, there was a dramatic reduction in size of the CMAP. A positive correlation was found between percent change in thenar MUNE at T(4) and at T(12) (P < 0.001). CONCLUSION: AMPS is a useful technique to document MUNE, SMUP size and CMAP size changes over time in patients with ALS.
Disciplines :
Neurology
Author, co-author :
Wang, François-Charles ; Centre Hospitalier Universitaire de Liège - CHU > Médecine de l'appareil locomoteur
Bouquiaux, Olivier ; Centre Hospitalier Universitaire de Liège - CHU > Médecine de l'appareil locomoteur
De Pasqua, Victor ; Centre Hospitalier Universitaire de Liège - CHU > Neurologie CHR
Delwaide, Paul ; Université de Liège - ULiège > Services généraux (Faculté de médecine) > Relations académiques et scientifiques (Médecine)
Language :
English
Title :
Changes in motor unit numbers in patients with ALS: a longitudinal study using the adapted multiple point stimulation method.
Publication date :
2002
Journal title :
Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders
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