Table 5 Nerve conduction studies. One patient in the diabetes without polyneuropathy group (group 3) refused to undergo NCS. High missing numbers as indicated for the individual measurements were mainly caused by electrically not excitable nerves. A p value < 0.05 was considered statistically significant.
Group 1 (CIDP without diabetes) | Group 2 (CIDP with diabetes) | Group 3 (Diabetes without neuropathy) | Group 4 (Diabetes with DPN) | Mann-Whitney U test group 2 vs. group 4 | |||
|---|---|---|---|---|---|---|---|
Measurement | Cut-off value | 68 | 32 | 24 | 83 | ||
Median Nerve | distal motor latency, ms (IQR) | 4.2 | 4.1 (1.8) | 4.9 (1.4) | 4.1 (0.7) | 4.4 (1.1) | p = 0.632 |
CMAP amplitude, mV (IQR) | 5.0 | 10.0 (6.1) | 7.6 (4.9) | 10.7 (7.0) | 9.3 (4.6) | p = 0.280 | |
MCV, m/s (IQR) | 50.0 | 46.6 (12.8) | 43.6 (11.2) | 52.8 (3.9) | 50.0 (6.0) | p < 0.001 | |
SNAP, µV (IQR) | 6.9 | 5.1 (8.2) | 0.9 (7.7) | 16.8 (17.8) | 10.4 (8.9) | p < 0.001 | |
SCV, m/s (IQR) | 45 | 45.0 (11.8) 19 (27.9%) missing | 43.7 (13.3) 16 (50.0%) missing | 49.1 (11.5) | 42.9 (9.4) 9 (10.8%) missing | p = 1.000 | |
minimal F-Wave latency, ms (IQR) | 31.0 | 32.8 (6.3) 14 (20.6%) missing | 32.7 (6.1) 12 (37.5%) missing | 26.0 (3.6) | 29.2 (3.7) 2 (2.4%) missing | p = 0.007 | |
Tibial Nerve | distal motor latency, ms (IQR) | 5.1 | 5.1 (3.0) | 5.4 (2.0) | 4.2 (1.4) | 4.7 (1.7) | p = 0.196 |
CMAP amplitude, mV (IQR) | 5.0 | 1.6 (5.73) | 1.0 (3.7) | 12.4 (9.9) | 6.7 (8.2) | p < 0.001 | |
MCV, m/s (IQR) | 40.6 | 37.0 (9.7) 12 (17.6%) missing | 35.7 (6.5) 11 (34.4%) missing | 42.8 (6.4) | 37.9 (5.9) 7 (8.4%) missing | p = 0.479 | |
minimal F-Wave latency, ms (IQR) | 58.0 | 67.0 (15.7) 40 (58.8%) missing | 67.0 (14.6) 23 (71.9%) missing | 52.8 (4.3) | 59.1 (7.4) 10 (12.0%) missing | p = 1.000 | |
Sural Nerve | SNAP amplitude, µV (IQR) | < 40 years: 4.9 > 40 years: 3.8 | 2.1 (6.3) 5 (7.4%) missing | 0 (0) 4 (12.5%) missing | 5.6 (4.3) | 0 (2.7) | p = 1.000 |
SCV, m/s (IQR) | < 40 years: 41.3 > 40 years: 39.3 | 40.0 (9.6) 33 (48.5%) missing | 35.5 (5.7) 26 (81.3%) missing | 42.8 (4.5) 2 (8.3%) missing | 38.2 (4.2) 49 (59.0%) missing | p = 1.000 | |
