Escorcio-Bezerra ML, Abrahao A, Santos-Neto D, de Oliveira Braga NI, Oliveira ASB, Manzano GM. Why averaging multiple MUNIX measures in the longitudinal assessment of patients with ALS?
Clin Neurophysiol 2017;
128:2392-2396. [PMID:
29096211 DOI:
10.1016/j.clinph.2017.09.104]
[Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 07/31/2017] [Accepted: 09/10/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE
To assess the impact of averaging multiple MUNIX trials on the follow-up of patients with amyotrophic lateral sclerosis (ALS).
METHODS
We determined the percent relative change (%RC) of MUNIX, in healthy subjects and patients with ALS, by subtracting the MUNIX value in the second visit from the first. Both the mean of a set of three MUNIX (mean-MUNIX) and the first MUNIX sample (single-MUNIX) were evaluated. Then, we studied the sensitivity to detect relative changes over time and the statistical dispersion of the %RC from these two parameters.
RESULTS
We found that the mean-MUNIX %RC has lower mean coefficient of variation than the single-MUNIX %RC in all muscles. The mean-MUNIX also resulted in more ALS patients with significant %RC, i.e., outside reference limits.
CONCLUSION
The mean-MUNIX resulted in less dispersed values of %RC in patients with ALS and thus, increased the precision of the technique. The mean-MUNIX resulted also in an increase in the sensitivity to track changes over time in these patients.
SIGNIFICANCE
The mean-MUNIX should be considered in any ALS follow-up study as a more reliable approach and as a way of potentially reducing the sample size needed for the study.
Collapse