TABLE 2.
Neurologic function at baseline by allocated treatment1
| Vitamin B-12 (n = 99) | Placebo (n = 100)2 | |
| Motor nerve conduction | ||
| Posterior tibial CMAP amplitude (primary outcome), mV | 4.6 (0–18.0)3 | 4.9 (0–13.6) |
| Posterior tibial conduction velocity,4 m/s | 39.9 ± 5.05 | 40.1 ± 5.2 |
| Common peroneal CMAP amplitude, mV | 2.2 (0–8.8) | 2.5 (0–8.2) |
| Common peroneal conduction velocity,4 m/s | 42.5 ± 4.6 | 43.0 ± 4.1 |
| Sensory nerve conduction | ||
| Sural SAP amplitude, μV | 3.8 (0–17.5) | 3.8 (0–14.2) |
| Sural conduction velocity,6 m/s | 40.6 ± 5.2 | 40.2 ± 5.3 |
| Superficial peroneal SAP amplitude, μV | 2.4 (0–13.2) | 3.4 (0–16.7) |
| Superficial peroneal conduction velocity,7 m/s | 41.2 ± 6.0 | 41.0 ± 5.2 |
| Central motor conduction | ||
| Right abductor digiti minimi motor evoked potential amplitude, mV | 3.3 ± 1.4 | 3.4 ± 1.5 |
| Central motor conduction time, right abductor digiti minimi, ms | 5.5 ± 1.2 | 5.5 ± 1.4 |
| Central motor conduction time, right abductor hallucis,4 ms | 13.6 ± 3.3 | 13.6 ± 3.5 |
| Clinical nerve outcomes | ||
| Absent right leg knee jerk, n (%) | 11 (11.1) | 8 (8.0) |
| Absent right leg ankle jerk, n (%) | 33 (33.3) | 22 (22.0) |
| Absent right great toe position sense, n (%) | 4 (4.0) | 8 (8.0) |
| Absent right great toe vibration sense, n (%) | 66 (66.7) | 66 (66.0) |
| Timed up-and-go, s | 10.4 ± 3.0 | 10.7 ± 3.5 |
1
CMAP, compound muscle action potential; SAP, sensory action potential.
2
Two participants randomly assigned to placebo provided no baseline nerve function data.
3
Median; range in parentheses (all such values).
4
Small amounts of missing data (n < 10 in each arm).
5
Mean ± SD (all such values).
6
Missing data (n = 11 in vitamin B-12 and n = 16 in placebo).
7
Missing data (n = 23 in vitamin B-12 and n = 17 in placebo).