Vincristine neuropathy in type I and type II Charcot-Marie-Tooth disease (hereditary motor sensory neuropathy).

A patient with Ewing's sarcoma and demyelinating type Charcot-Marie-Tooth disease (CMT) developed severe neuropathy after receiving a total vincristine dose of 6 mg. Recovery was slow and incomplete. A second patient with axonal type CMT developed moderate neuropathy but tolerated extended vincristine administration and recovered quickly. Possible underlying neuropathy should be excluded before vincristine treatment is begun by careful examination including inspection of the feet, followed by electrophysiologic studies as indicated. In demyelinating CMT, vincristine should be avoided; in axonal form cautious use may be considered.