Lumbosacral polyradiculopathy after intrathecal chemotherapy in pediatric acute lymphoblastic leukemia

Excerpt

A 4-year-old girl received induction chemotherapy consisting of vincristine, daunorubicin, L-asparaginase, and prednisolone for acute lymphoblastic leukemia of the B-cell precursor phenotype. Cerebrospinal fluid examination revealed 1 white blood cell/µL, with 68% leukemic blasts (CNS-2), and she received weekly intrathecal therapy consisting of methotrexate, cytarabine, and prednisolone (triple IT) during induction chemotherapy. After three doses of triple IT over 3 weeks, she developed incontinence and progressive flaccid paralysis of the legs. She was unable even to turn over in bed due to weakness of the trunk muscles. Neurological examination revealed areflexia of both legs, with no sensory deficit. Hematological and serological studies were normal. Cerebrospinal fluid examination showed 1 white blood cell/μL, absence of malignant cells, and was normal for protein (22 mg/dL) and myelin basic protein. Nerve conduction studies were consistent with motor lumbosacral polyradiculopathy without peripheral neuropathy; lower extremity nerve conduction velocities and amplitude of compound muscle action potential were normal, with no temporal dispersion or conduction block; however, F waves were absent (Fig. 1). Spinal magnetic resonance imaging (MRI) showed gadolinium enhancement of the anterior roots at the cauda equina (Fig. 2a, b), confirming a diagnosis of lumbosacral polyradiculopathy. Triple IT was stopped and the patient received intravenous methylprednisolone (30 mg/kg/day) for 3 days, after which chemotherapy was restarted without triple IT. After 4 months of rehabilitation, although the strength of her leg muscles gradually improved, they remained unable to bear weight.

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