PMC7642643_01
(A) Survival analysis for all ALS patients. (B) Survival analysis for patients with NI <= 2.15 vs. NI > 2.15. NI, neurophysiological index.
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F1
The median survival time of all the cases was 33.0 months as shown by Kaplan-Meier analysis (Figure 1A). In addition, a significant difference in median survival time was observed between the fast progression group (NI <= 2.15) and the slow progression group (NI > 2.15; 28.0 vs. 39.0 months; p = 0.0018) (Figure 1B). It showed that NI was not significantly correlated with serum CK level (rs = -0.1761, p = 0.0124; Supplementary Figure 1A) and creatinine level (rs = 0.09209, p = 0.1946; Supplementary Figure 1B).
(A) Correlation between NI and ALSFRS-R scores at baseline (rs = 0.3153, p < 0.0001). (B) Correlation between NI and ALSFRS-R scores at different time points of follow-up (rs = 0.5127, p < 0.0001). NI, neurophysiological index; ALSFRS-R, amyotrophic lateral sclerosis functional rating scale-revised; rs, Spearman coefficient.
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ALSFRS-R scores at baseline (rs = 0.3153, p < 0.0001; Figure 2A). As a retrospective case series study with follow-up, we also calculated the median nerve NI for 81 ALS patients at different time points of follow up, including 39 ones at 3 months, 20 ones at 6 months, 9 ones at 9 months, and 13 ones at more than 9 months. A similar correlation between median nerve NI and ALSFRS-R scores was confirmed (rs = 0.5127, p < 0.0001; Figure 2B).
(A) Survival analysis for patients with DeltaNI <= 0.25 vs. DeltaNI > 0.25. (B) Survival analysis for patients with predictive score <= 14 vs. predictive score > 14. NI, neurophysiological index.
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The higher median nerve NI slope of decline (DeltaNI > 0.25) showed shorter median survival, compared with the lower group (DeltaNI <= 0.25) (34.0 vs. 52.0 months, p = 0.0003; Figure 3A). We calculated the predictive score for all ALS patients, and the higher predictive score (> 14) showed significantly shorter median survival compared with the lower group ( <= 14; HR = 3.907; 95% CI, 2.857-5.342), and the median survival was 20.0 and 43.0 months, respectively (Chi-square = 84.71; p < 0.0001 (Figure 3B).