TABLE 7.
Neuroelectrophysiologic manifestations in nitrous oxide (N2O) abuse patients
| Parameter | n/N (%) |
|---|---|
| Motor conduction | |
| Abnormal number | 28/32 (88%) |
| CMAP amplitude decrease | 25/32 (78%) |
| MCV decrease | 27/32 (84%) |
| Prolonged exercise latency | 14/32 (44%) |
| Sensory conduction | |
| Abnormal number | 31/32 (97%) |
| SNAP amplitude decrease | 17/32 (53%) |
| SCV decrease | 31/32 (97%) |
| F wave | |
| Abnormal number | 31/32 (97%) |
| Decrease or disappearance | 24/32 (75%) |
| Prolonged latency period | 27/32 (84%) |
| H reflex | |
| Abnormal number | 24/24 (100%) |
| Decrease or disappearance | 6/24 (25%) |
| Prolonged latency period | 18/24 (75%) |
| Denervation potential detected by EMG | 21/32 (67%) |
Abbreviations: CMAP, compound muscle action potential; EMG, electromyogram; MCV, motor conduction velocity; SNAP, sensory nerve action potential; SVC, sensory conduction velocity.