Vincristine-induced neurotoxicity: electrophysiological features in children

Objective: Neuropathy caused by vincristine toxicity can be diagnosed by electrophysiological examination. The purpose of this study is to demonstrate the electrophysiological features of vincristine toxicity. Methods: Electrophysiological data from 25 children receiving vincristine treatment and 25 normal controls were evaluated retrospectively. Nerve conduction study (NCS) parameters were compared. Additionally amplitude and negative peak duration (NPD) of distal compound muscle action potentials (CMAP) were analysed by factor analysis. Results: Distal CMAP amplitudes in the patient group were significantly lower and the distal CMAP NPDs were prolonged. There were no significant differences in other motor and sensory NCS parameters. Conclusion: Contrary to generally accepted sensorimotor involvement, motor NCS abnormalities are more pronounced in vincristine toxicity. The current study is the first time prolonged distal CMAP NPDs were detected and indicated in vincristine-related weakness, which may be a clue to understanding its mechanism, as well as differentiating from other situations.