Vincristine-Induced Neuropathies: An Atypical ENMG Pattern in Children (IN1-1.006)

OBJECTIVE: To describe the clinical and electrophysiological features of vincristine-induced neuropathies in children. BACKGROUND: Vincristine is a drug frequently used in cancerology and hematology. Its main side-effect is a length-dependent axonal neuropathy. Only a few studies have described these neuropathies in children. DESIGN/METHODS: This retrospective descriptive study was performed on a cohort of 17 children aged 1-17 years, who presented with a neuropathy and underwent electroneuromyography examination (ENMG) between March, 2009 and April, 2012. Clinical and anamnestic data were correlated to the ENMG results. RESULTS: Thirteen children presented with a motor deficit, 12 with paresthesia or neuropathic pain, 2 with cranial nerve involvement. All had tendon areflexia. 11 patients had minor dysautonomia signs (constipation). Four children could not walk any longer. ENMG showed an axonal neuropathy in all the patients: (i) non-length-dependent with a strong motor predominance in 9 children, 4 of them presenting with a clear multineuropathy pattern ; (ii) length-dependent sensory-motor in 7 children; (iii) only sensory in 1 patient. Patients in (i) were younger (mean age 7.5 y.o) than in (ii) (mean age 14.8). Also, the mean delay for diagnosis after vincristine treatment onset was about 53 days in (i) 187 days in (ii). ENMG abnormalities were more severe in the latter group. Vincristine was stopped in 6 children, because of neurotoxicity. CONCLUSIONS: This electrical and clinical motor predominance differs from the mainly sensory neuropathy encountered in adults. It seems to be characteristic of vincristine-induced neuropathies in children, especially the younger ones. The pattern of sensori-motor multineuropathy found in 4 children has not been described previously. Dysesthesia and neuropathic pain observed in 12 patients are probably due to small-fiber neuropathy, probably linked to the frequently associated dysautonomia. Disclosure: Dr. Pouclet-Courtemanche has nothing to disclose. Dr. Magot has nothing to disclose. Dr. Ollivier has nothing to disclose. Dr. Rialland has nothing to disclose. Dr. Leclair-Visonneau has nothing to disclose. Dr. Fayet has nothing to disclose. Dr. Camdessanche has nothing to disclose. Dr. Pereon has nothing to disclose.