Table 5.
Comparison of different diagnostic strategies for small fiber neuropathy.
| Tests combination | Total population | Definite SFN | Possible SFN | No SFN | Sensitivity (CI 95%) | Specificity (CI 95%) | PPV | NPV |
|---|---|---|---|---|---|---|---|---|
| Total | 245 | 102 | 53 | 90 | ||||
| Skin biopsy + ESC measurement + LEP + QST | ||||||||
| <2 abnormal tests | 108 | 8 | 21 | 79 | 0.92 (0.85–0.97) |
0.88 (0.79–0.94) |
0.9 | 0.91 |
| ≥2 abnormal tests | 137 | 94 | 32 | 11 | ||||
| Skin biopsy + ESC measurement + LEP | ||||||||
| <2 abnormal tests | 138 | 28 | 28 | 82 | 0.67 (0.57–0.76) |
1.00 (0.96–1.00) |
1 | 0.73 |
| ≥2 abnormal tests | 107 | 74 | 25 | 8 | ||||
| Skin biopsy + LEP + QST | ||||||||
| <2 abnormal tests | 149 | 29 | 36 | 84 | 0.72 (0.62–0.8) |
0.93 (0.86–0.98) |
0.92 | 0.75 |
| ≥2 abnormal tests | 96 | 73 | 17 | 6 | ||||
| Skin biopsy + ESC measurement + QST | ||||||||
| <2 abnormal tests | 166 | 34 | 42 | 90 | 0.73 (0.61–0.81) |
0.91 (0.83–0.96) |
0.9 | 0.75 |
| ≥2 abnormal tests | 79 | 68 | 11 | 0 | ||||
| LEP + ESC measurement + QST | ||||||||
| <2 abnormal tests | 137 | 27 | 28 | 82 | 0.74 (0.62–0.82) |
0.91 (0.83–0.96) |
0.9 | 0.76 |
| ≥2 abnormal tests | 108 | 75 | 25 | 8 | ||||
QST, Quantitative Sensory Testing; ESC, Electrochemical Skin Conductance; LEP, Laser Evoked Potentials; PPV, Positive Predictive Value; NPV, Negative Predictive Value.