Table 4.
Diagnostic performance of F-wave parameters in ALS patients.
| Parameters | Cut-off value | Sensitivity (%) | Specificity (%) | Youden index | AUC (95% CI) | P-value |
|---|---|---|---|---|---|---|
| EDB | ||||||
| Min F latency (ms/m) | 26.57 | 63.6 | 82 | 0.46 | 0.803(0.733–0.872) | <0.001 |
| Max F latency (ms/m) | 29.49 | 71.7 | 86 | 0.58 | 0.868(0.812–0.924) | <0.001 |
| Mean F latency (ms/m) | 28.15 | 66.7 | 90 | 0.57 | 0.842(0.780–0.903) | <0.001 |
| F-wave chronodispersion (ms) | 5.45 | 57.6 | 86 | 0.44 | 0.688(0.604–0.772) | <0.001 |
| F-wave persistence (%) | 15.50 | 22.2 | 100 | 0.22 | 0.580(0.486–0.673) | 0.113 |
| Mean F-wave amplitude (μV) | 175.50 | 56.6 | 88 | 0.45 | 0.711(0.627–0.796) | <0.001 |
| Mean F/M amplitude ratio (%) | 2.81 | 64.6 | 88 | 0.53 | 0.827(0.762–0.893) | <0.001 |
| Max F/M amplitude ratio (%) | 7.77 | 54.5 | 86 | 0.41 | 0.758(0.680–0.835) | <0.001 |
| Index Freps (%) | 27.33 | 84.8 | 78 | 0.63 | 0.869(0.809–0.929) | <0.001 |
| AH | ||||||
| Min F latency (ms/m) | 27.86 | 39.4 | 92 | 0.31 | 0.683(0.598–0.767) | <0.001 |
| Max F latency (ms/m) | 31.02 | 48.5 | 96 | 0.44 | 0.780(0.707–0.852) | <0.001 |
| Mean F latency (ms/m) | 29.54 | 40.4 | 100 | 0.40 | 0.735(0.657–0.814) | <0.001 |
| F-wave chronodispersion (ms) | 5.25 | 63.6 | 82 | 0.46 | 0.756(0.680–0.831) | <0.001 |
| F-wave persistence (%) | 99.50 | 12.1 | 100 | 0.12 | 0.561(0.466–0.655) | 0.228 |
| Mean F-wave amplitude (μV) | 431.50 | 56.6 | 80 | 0.37 | 0.677(0.593–0.761) | <0.001 |
| Mean F/M amplitude ratio (%) | 2.65 | 59.6 | 92 | 0.52 | 0.770(0.697–0.844) | <0.001 |
| Max F/M amplitude ratio (%) | 5.97 | 54.5 | 94 | 0.49 | 0.753(0.678–0.828) | <0.001 |
| Index Freps (%) | 1.00 | 29.3 | 100 | 0.29 | 0.646(0.560–0.733) | 0.004 |
ALS, amyotrophic lateral sclerosis; HCs, healthy controls; EDB, extensor digitorum brevis muscle; HA, abductor halluces muscle; AUC, area under the curve; CI, confidence interval. Values with significant differences printed in bold characters.