Table 6.
Diagnostic performance of F-wave parameters in lower extremity nerves in spinobulbar muscular atrophy.
| Vs. ALS |
Vs. control |
|||||||
|---|---|---|---|---|---|---|---|---|
| Parameters | Cut-off value | Sen (%) | Spe (%) | AUC (95% CI) | Cut-off value | Sen (%) | Spe (%) | AUC (95% CI) |
| Tibial nerve | ||||||||
| Min F latency | 44.9 ms | 56.9 | 58.6 | 0.550 (0.459–0.638) P = 0.339 | 47.8 ms | 25.9 | 89.3 | 0.510 (0.415–0.605) P = 0.858 |
| F persistence | 99% | 33.3 | 80.6 | 0.569 (0.480–0.655) P = 0.079 | 99% | 33.3 | 96.4 | 0.651 (0.557–0.737) P < 0.001 |
| Mean Famp | 479 μV | 30 | 89.2 | 0.533 (0.429–0.635) P = 0.581 | 419 μV | 40 | 89.3 | 0.669 (0.575–0.753) P < 0.001 |
| Max Famp | 970 μV | 51.7 | 77.8 | 0.678 (0.591–0.757) P < 0.001 | 818 μV | 68.3 | 82.1 | 0.797 (0.712–0.866) P < 0.001 |
| Giant F-wave | 1.0% | 43.3 | 87.5 | 0.636 (0.548–0.718) P < 0.001 | 1.0% | 43.3 | 98.2 | 0.698 (0.606–0.780) P < 0.001 |
| Peroneal nerve | ||||||||
| Min F latency | 38.3 ms | 22.0 | 89.4 | 0.516 (0.421–0.609) P = 0.781 | 45.5 ms | 40.0 | 86.7 | 0.533 (0.436–0.629) P = 0.585 |
| F persistence | 49% | 76.9 | 63.2 | 0.701 (0.611–0.781) P < 0.001 | 46.0% | 75 | 53.3 | 0.640 (0.543–0.728) P = 0.008 |
| Mean Famp | 268 μV | 69.2 | 86.8 | 0.811 (0.729–0.877) P < 0.001 | 201 μV | 82.7 | 88.3 | 0.877 (0.802–0.932) P < 0.001 |
| Max Famp | 586 μV | 65.4 | 76.5 | 0.742 (0.654–0.818) P < 0.001 | 543 μV | 71.2 | 83.3 | 0.817 (0.733–0.884) P < 0.001 |
| Giant F% | 3.1% | 51.9 | 91.2 | 0.697 (0.606–0.777) P < 0.001 | 1.8% | 53.8 | 98.3 | 0.750 (0.660–0.827) P < 0.001 |
ALS, amyotrophic lateral sclerosis; AUC, area under the curve; CI, confidence interval; Max Famp, maximum F-wave amplitude; Min F latency, minimum F-wave latency; Sen, sensitivity; Spe, specificity.