TY - JOUR
T1 - MUNIX and incremental stimulation MUNE in ALS patients and control subjects
AU - Furtula, Jasna
AU - Johnsen, Birger
AU - Christensen, Peter Broegger
AU - Pugdahl, Kirsten
AU - Bisgaard, Carsten
AU - Christensen, Mette Kirstine
AU - Arentsen, Jens
AU - Frydenberg, Morten
AU - Fuglsang-Frederiksen, Anders
PY - 2013/3/1
Y1 - 2013/3/1
N2 - Objective: This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS. Methods: Thirteen ALS patients and 48 control subjects were prospectively investigated - both groups were studied with MUNIX and IS-MUNE applied on the abductor digiti minimi (ADM) muscle. Additional retest was performed on 14 control subjects. Follow-up tests were carried out on 6 patients. The analysis included measures of reproducibility (Intraclass Correlation Coefficient (ICC)) and diagnostic performance (Receiver Operating Characteristic (ROC) analysis). Results: Test-retest reproducibility was low to moderate for MUNIX and IS-MUNE (ICC. = 0.38 and 0.56, respectively). Repeated MUNIX and IS-MUNE measurements on the same subject had a mean percentage difference (MPD) of 20% and 46%, respectively (p= 0.039). In the control group, the coefficient of variation was markedly lower for MUNIX than for IS-MUNE (26% and 44%, respectively, p<. 0.0005). In ALS patients MUNIX had a notably better responsiveness in follow-up than IS-MUNE (percent change per month, 9.4 versus 5.6, p= 0.046). ROC analysis suggested similar diagnostic accuracy of both tests. Conclusions: MUNIX is a useful MUNE indicator when assessing progression of lower motor neuron affection in ALS. Furthermore, MUNIX displayed lower intrasubject variability, but no evident better diagnostic yield compared with IS-MUNE. Significance: This study has established comparative assessment of MUNIX and IS-MUNE performance in test-retest setting and as diagnostic tests on a distal muscle in ALS patients.
AB - Objective: This study compares the new Motor Unit Number Estimation (MUNE) technique, MUNIX, with the more common incremental stimulation MUNE (IS-MUNE) with respect to reproducibility in healthy subjects and as potential biomarker of disease progression in patients with ALS. Methods: Thirteen ALS patients and 48 control subjects were prospectively investigated - both groups were studied with MUNIX and IS-MUNE applied on the abductor digiti minimi (ADM) muscle. Additional retest was performed on 14 control subjects. Follow-up tests were carried out on 6 patients. The analysis included measures of reproducibility (Intraclass Correlation Coefficient (ICC)) and diagnostic performance (Receiver Operating Characteristic (ROC) analysis). Results: Test-retest reproducibility was low to moderate for MUNIX and IS-MUNE (ICC. = 0.38 and 0.56, respectively). Repeated MUNIX and IS-MUNE measurements on the same subject had a mean percentage difference (MPD) of 20% and 46%, respectively (p= 0.039). In the control group, the coefficient of variation was markedly lower for MUNIX than for IS-MUNE (26% and 44%, respectively, p<. 0.0005). In ALS patients MUNIX had a notably better responsiveness in follow-up than IS-MUNE (percent change per month, 9.4 versus 5.6, p= 0.046). ROC analysis suggested similar diagnostic accuracy of both tests. Conclusions: MUNIX is a useful MUNE indicator when assessing progression of lower motor neuron affection in ALS. Furthermore, MUNIX displayed lower intrasubject variability, but no evident better diagnostic yield compared with IS-MUNE. Significance: This study has established comparative assessment of MUNIX and IS-MUNE performance in test-retest setting and as diagnostic tests on a distal muscle in ALS patients.
KW - Amyotrophic lateral sclerosis
KW - Incremental stimulation
KW - Motor unit number estimation
KW - MUNIX
KW - Surface-recorded motor unit potentials
KW - Test-retest reproducibility
U2 - 10.1016/j.clinph.2012.08.023
DO - 10.1016/j.clinph.2012.08.023
M3 - Journal article
C2 - 23040293
AN - SCOPUS:84873276450
SN - 1388-2457
VL - 124
SP - 610
EP - 618
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 3
ER -