Diagnosis of Charcot-Marie-Tooth disease in a child with orbital rhabdomyosarcoma and vincristine-induced axonal polyneuropathy

Abstract

Background: Axonal polyneuropathy is a common manifestation of vincristine toxicity. Worsening of an unknown hereditary neuropathy has been described in children with hematological and solid tumors undergoing vincristine-based chemotherapy. Case report: We describe an 8-year-old girl who presented with acute quadriplegia within a week from vincristine chemotherapy for an ocular rhabdomyosarcoma. The child became wheelchair-bound, with loss of motility and areflexia. The neurophysiological study showed severe axonal sensory-motor polyneuropathy. An ultrasound of the nerve showed nerve enlargement in all the four limbs. The patient's mother reported being affected by Charcot-Marie-Tooth 1A (CMT1A) neuropathy. Vincristine was discontinued. Genetic analysis in the child was positive for duplication of the PMP22 gene. Conclusion: The possibility of hereditary neuropathy should be ruled out before starting vincristine therapy by family history and neurological examination. Ultrasound of the nerve, where available, may be considered as a non-invasive screening tool. It is useful to direct genetic testing in patients with abnormal neurological examination or a positive family history.

Keywords

• Hereditary neuropathy
• Charcot-marie- tooth disease
• Ultrasound imaging
• Vincristine
• Chemotherapy