Table 1.
Results of nerve conduction studies (right side unless otherwise mentioned) at months 2.5 (A), 4 (B) and 7 (C) after the onset of neurological manifestationsa
| Nerve | Recording site | Parameters | A | B | C | Normal |
|---|---|---|---|---|---|---|
| Motor studies | ||||||
| Median | Abductor pollicis brevis | Distal latency (ms) | 4.5 | 17.4 | <4.0 | |
| Amplitude (mV) | 6.8 | 0.2 | >5 | |||
| Duration (ms) | 10 | 37.8 | <6 | |||
| CV (m/s) | 52 | 0 | >50 | |||
| Tibial | Abductor hallucis | Distal latency (ms) | NR | 0 | <6.5 | |
| Amplitude (mV) | >3 | |||||
| Peroneal | Extensor digitorum brevis (Tibialis anterior) | Distal latency (ms) | 7.5 | 0(6) | 12 | <6.0 (<2.0) |
| Amplitude (mV) | 0.4 | (0.1) | 0.4 | >3 (>4) | ||
| Duration (ms) | (15) | 15 | <6 (<8) | |||
| F-wave latency (ms) | 0 | <52 | ||||
| Sensory studies | ||||||
| Median (digit 2) | Wrist | Amplitude (μV) | 0 | NR | >7 | |
| Sural | Ankle (right and left) | Amplitude (μV) | 0 | 0 | 0 | >5 |
aData are all abnormal, characterized by prolonged distal motor latencies and desynchronization of the motor responses, and absence of sensory responses, suggestive of sensorimotor demyelinating neuropathy—ms, milliseconds; μV or mV, micro or millivolts; m/s, metre/second; CV, conduction velocity; NR, not recorded; 0, absent.