NCMP-14. NEUROTOXICITY AFTER A SINGLE CYCLE OF INTRAVENOUS CYTARABINE

Abstract Cytarabine neurotoxicity is well-documented, typically occurring after intrathecal treatment or a cumulative systemic dose of 36 g/m2. Encephalopathy, myelopathy, and acute cerebellar syndrome have all been described, with risk factors including advanced age and renal dysfunction. Here, we report a case of acute cerebellar syndrome after a single cycle of intravenous cytarabine 3 g/m2. This 65 year old man with history of chronic kidney disease (baseline creatinine 2.0 mg/dL) and primary central nervous system lymphoma had unconfirmed complete response after induction therapy with rituximab, methotrexate, and vincristine. Methotrexate was dosed between 1 -2 g/m2 due to renal dysfunction and delayed clearance. Given patient’s performance status and comorbidities, high-dose cytarabine consolidation was chosen. He received 3 g/m2 intravenously on days 1 and 2 of a 28-day cycle. On day 5, he developed acute truncal ataxia and was no longer able to sit or stand unsupported. He then presented to the emergency department on day 8 with persistent symptoms. Vital signs showed mild hypertension without orthostatic hypotension. Neurologic exam revealed postural instability, titubation, and inability to maintain seated posture with eyes closed. He had no dysmetria on finger-nose or heel-shin testing. Blood values were notable only for an elevated creatinine of 2.1 mg/dL. CT head revealed no acute pathology. MRI brain showed no infarct or recurrent disease. He was discharged home and symptoms resolved by day 10. Given clinical syndrome of truncal ataxia shortly after cytarabine, we diagnosed cytarabine-related neurotoxicity. Further cycles of consolidation were withheld for close observation. While cytarabine-related neurotoxicity is more common after an increased cumulative dose, it can occur after only a single cycle of 3 g/m2. Our patient’s age and baseline renal dysfunction likely predisposed him. Cytarabine dose-reduction can be considered in patients with these risk factors.