MBCL-01. VINCRISTINE NEUROTOXICITY UNMASKING CHARCOT-MARIE-TOOTH DISEASE Free

Vincristine-induced neuropathy has been well described in the literature. However, few cases of underlying hereditary neuropathy revealed after vincristine therapy in pediatrics have been reported. We present a case of a 6 year old female with medulloblastoma. Patient presented with two weeks of headaches, gait instability, and vomiting. Pathology from tumor resection was consistent with SHH medulloblastoma. She started treatment per the SJMB12 study and received CSI+ focal boost for average risk disease followed by chemotherapy with vincristine, cisplatin, and cyclophosphamide. Ten days after Cycle 2, she developed lower extremity weakness that ascended to her upper extremities. Magnetic resonance imaging of the brain and spine noted thickening and enhancement of lower cranial nerves and the anterior and posterior spinal nerve roots. A presumptive diagnosis of Guillain-Barre syndrome was made and she received IVIG 1 mg/kg daily for three consecutive days. Vincristine was removed from her treatment regime given its known association with peripheral neuropathy. Further evaluation of patient noted presence of deep tendon reflexes and persistent foot drop, leading to consideration of hereditary neuropathy. Subsequent genetic testing revealed previously asymptomatic and undiagnosed CMT1A. Decision was made to exclude Cisplatin from her regime due to reported exacerbations of underlying peripheral neuropathy. At the time of this report, our patient is without disease three months post-treatment. She has returned to school and shown significant improvements with physical therapy. This case highlights the importance of early recognition of acute vincristine neurotoxicity as it may raise a suspicion of an underlying hereditary neuropathy.