Table 8.
Small fiber examinations.
| FMS | SFN | P | |
|---|---|---|---|
| Skin biopsy | |||
| Median IENFD lower leg (fibers/mm) [range] | 6.3 [0.0 to 14.4] | 5.4 [0.0 to 16.3] | n.s. |
| Median IENFD upper thigh (fibers/mm) [range] | 8.4 [1.2 to 20.0] | 8.8 [1.5 to 16.5] | n.s. |
| QST: median [range] | |||
| CDT (°C) | −2.2 [−22.0 to −0.9] | −3.9 [-22.0 to −0.8] | <0.001 |
| WDT (°C) | 6.7 [1.8 to 18.0] | 5.4 [1.0 to 17.6] | n.s. |
| TSL (°C) | 10.5 [1.5 to 40.0] | 11.1 [4.0 to 40.0] | n.s. |
| PHS (x/3) | 0.0 [0 to 3] | 0.0 [0 to 3] | n.s. |
| CPT (°C) | 16.1 [10.0 to 30.6] | 11.1 [10.0 to 29.4] | <0.05 |
| HPT (°C) | 45.2 [35.8 to 50.0] | 46.0 [37.2 to 50.0] | n.s. |
| MDT (mN) | 2.1 [0.2 to 724.1] | 4.9 [0.2 to 207.9] | <0.001 |
| MPT (mN) | 59.7 [5.7 to 724.1] | 27.9 [5.7 to 724.1] | <0.01 |
| MPS (rating) | 1.8 [0.0 to 72.7] | 1.3 [0.0 to 20.3] | n.s. |
| DMA (rating) | 0.0 [0.0 to 70.6] | 0.0 [0.0 to 5.3] | n.s. |
| WUR (ratio) | 2.0 [0.0 to 42.0] | 2.0 [1.0 to 5.0] | n.s. |
| VDT (x/8) | 7.0 [3 to 8] | 6.5 [5 to 8] | n.s. |
| PPT (kPa) | 368.0 [196 to 1030] | 441.0 [235 to 840] | <0.01 |
| CCM | |||
| Median NFD (fibers/mm2) [range] | 23.0 [5.2 to 38.5] | 23.0 [6.3 to 36.5] | n.s. |
| Median NBD (fibers/mm2) [range] | 66.6 [9.7 to 181.5] | 46.4 [10.4 to 102.1] | <0.001 |
| Median NFL (mm/mm2) [range] | 13.3 [5.7 to 21.8] | 13.1 [7.2 to 19.9] | n.s. |
| PREP (average left/right side): median [range] | |||
| Foot N1 latency (ms) | 168.2 [97.7 to 232.3] | 206.7 [0.0 to 285.3] | <0.001 |
| Foot P1 latency (ms) | 211.5 [118.9 to 310.6] | 272.8 [0.0 to 332.8] | <0.001 |
| Foot PPA (µV) | 11.7 [1.2 to 39.8] | 13.5 [0.0 to 26.9] | <0.05 |
CCM, corneal confocal microscopy; CDT, cold detection threshold; CPT, cold pain threshold; DMA, dynamic mechanical allodynia; FMS, fibromyalgia syndrome; HPT, heat pain threshold; IENFD, intraepidermal nerve fiber density; MDT, mechanical detection threshold; MPT, mechanical pain threshold; MPS, mechanical pain sensitivity; N1, first negative peak latency; NBD, nerve branch density; NFD, nerve fiber density; NFL, nerve fiber length; NRS, numeric rating scale; n.s., not significant; P1, subsequent positive peak latency; PHS, paradoxical heat sensations; PPA, peak-to-peak amplitudes; PPT, pressure pain threshold; PREP, pain-related evoked potentials; QST, quantitative sensory testing; SFN, small fiber neuropathy; TSL, thermal sensory limen; VDT, vibration detection threshold; WDT, warm detection threshold; WUR, wind-up ratio.