Table 5.
Diagnostic performance of F-wave parameters in upper 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) |
| Median nerve | ||||||||
| Min F latency | 25.3 ms | 76.7 | 56.3 | 0.644 (0.555–0.725) P = 0.001 | 24.1 ms | 53.3 | 73.3 | 0.609 (0.516–0.697) P = 0.039 |
| F persistence | 86.0% | 93.7 | 24.7 | 0.537 (0.450–0.623) P = 0.456 | 83.0% | 90.6 | 91.7 | 0.968 (0.920–0.991) P < 0.001 |
| Mean Famp | 269.0 μV | 78.1 | 54.8 | 0.701 (0.617–0.776) P < 0.001 | 509.0 μV | 32.8 | 100 | 0.675 (0.580–0.756) P < 0.001 |
| Max Famp | 1057 μV | 70.3 | 76.7 | 0.782 (0.705–0.859) P < 0.001 | 1131 μV | 65.6 | 80 | 0.751 (0.666–0.824) P < 0.001 |
| Giant F-wave | 1.09% | 43.8 | 93.2 | 0.686 (0.601–0.720) P < 0.0010.001 | 1.14% | 43.7 | 98.3 | 0.704 (0.615–0.782) P < 0.001 |
| Ulnar nerve | ||||||||
| Min F latency | 24.8 ms | 70.0 | 69.0 | 0.701 (0.615–0.778) P < 0.001 | 24.5 ms | 63.3 | 56.7 | 0.579 (0.486–0.669) P = 0.134 |
| F persistence | 92% | 82.8 | 54.8 | 0.637 (0.551–0.718) P = 0.005 | 95.3% | 95.3 | 90.0 | 0.981 (0.939–0.997) P < 0.001 |
| Mean Famp | 296 μV | 75.0 | 41.1 | 0.575 (0.487–0.659) P = 0.129 | 373 μV | 57.8 | 81.7 | 0.707 (0.618–0.785) P < 0.001 |
| Max Famp | 1352 μV | 64.1 | 72.6 | 0.730 (0.648–0.803) P < 0.001 | 1289 μV | 65.6 | 95 | 0.855 (0.780–0.912) P < 0.001 |
| Giant F% | 1.03% | 65.6 | 72.6 | 0.678 (0.593–0.756) P < 0.001 | 1.0% | 65.6 | 96.7 | 0.815 (0.737–0.879) 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.