Table 2.
Results of motor nerve conduction studies in patients with Guillain-Barre syndromea
| Nerve | Normal control |
Early
b
, < 2 weeks
|
Late
b
, ≥ 2 weeks
|
||||
|---|---|---|---|---|---|---|---|
| AIDP, n = 15 | AMAN, n = 8 | AMSAN, n = 2 | AIDP, n = 29 | AMAN, n = 8 | AMSAN, n = 8 | ||
| Median | |||||||
| CMAP amplitude (mV) | ≥ 4.0 | 2.1 (0-11.0) | 2.9 (0-11.0) | 3.30 (3.0-4.0) | 3.4 (0-10.0) | 2.8 (0-9.0) | 3.2 (1.0-11.0) |
| Motor DL (ms) | ≤ 4.4 | 6.4 (3.0-13) | 3.7 (3.0-5) | 3.10 (3.0-4.0) | 7.1 (NA-24.0) | 3.9 (3-9.0) | 3.6 (3.0-6.0) |
| NCV (m/s) | ≥ 49 | 47.8 (NA-70.0) | 53.0 (NA-60.4) | 52.7 (48.0-57.4) | 37.8 (NA-55.0) | 53.6 (50.0-62) | 48.0 (43.0-56.0) |
| Ulnar | |||||||
| CMAP amplitude (mV) | ≥ 6.0 | 3.0 (0-6.0) | 3.6 (0-5.7) | 2.8 (1.3-4.3) | 4.0 (0-12.6) | 2.2 (0-11.1) | 5.6 (0.5-13.8) |
| Motor DL (ms) | ≤ 3.3 | 4.2 (NA-8.5) | 3 (NA-4.2) | 3.1 (3-3.2) | 4.2 (NA-14.2) | 3.1 (NA-3.8) | 3.0 (2.2-4.9) |
| NCV (m/s) (B.e) | ≥ 49 | 45 (NA–63.3) | 60 (NA–68) | 67.5 (67-68) | 43 (NA-75.7) | 59.6 (NA-75) | 58.5 (49-70) |
| NCV (m/s) (A.e) | ≥ 44 | 32 (NA-55) | 45 (NA-75) | 38 (32-44) | 38 (NA-69.9) | 54 (NA-72.) | 54.5 (43-74) |
| Peroneal | |||||||
| CMAP amplitude (mV) | ≥ 2 | 1.2 (0-6.1) | 0.4 (0-8.8) | 0 | 1.2 (0-11.5) | 0.9 (0-3.5) | 0.5 (0-3.3) |
| Motor DL (ms) | ≤ 6.5 | 9.0 (NA-16.2) | 5.3 (NA-7.3) | NA | 7.5 (NA-16.5) | 6.3 (NA-8.3) | 4.8 (NA-6.7) |
| NCV (m/s) | ≥ 44 | 33 (NA-58.7) | 44.8 (NA–48) | NA | 32.6 (NA-65.2) | 44 (NA-59.6) | 35 (NA-42) |
| Tibial | |||||||
| CMAP amplitude (mV) | ≥ 4 | 0.5 (0-5.3) | 1.2 (0.1-6.3) | 1.5 (1.4-1.6) | 2.5 (0-12.3) | 1.5 (0-8.0) | 1.5 (0-7.7) |
| Motor DL (ms) | ≤ 5.8 | 6.7 (NA-14.2) | 7.1 (5.1-8.9) | 5.05 (5.0-5.1) | 6.5 (NA–14.7) | 6.7 (NA–8.9) | 4.5 (NA-7.5) |
| NCV (m/s) | ≥ 41 | 27.6 (NA-71) | 45 (37.2-47) | 45.8 (41.7-50) | 28.0 (NA–55.3) | 39.4 (NA-46) | 39 (NA-46) |
AIDP: Acute inflammatory demyelinating polyneuropathy; AMAN: Acute motor axonal polyneuropathy
AMSAN: Acute motor sensory axonal polyneuropathy; NCV: Nerve conduction velocity; DL: Distal latency
CMAP: Compound muscle action potential; B.e: Below elbow, A.e: Above elbow; NA: Not applicable
a
Data are presented in median (range).
b
Time of nerve conduction study from onset of symptoms.