Horner's syndrome and demyelinating peripheral neuropathy caused by high-dose cytosine arabinoside.

High-dose cytosine arabinoside may benefit patients with refractory acute leukemia. Peripheral nervous system disturbances caused by cytosine arabinoside have rarely been reported. We describe a patient with acute leukemia who developed Horner's syndrome and a severe demyelinating peripheral neuropathy leading to death after receiving high-dose cytosine arabinoside. Peripheral nerve dysfunction is a potentially serious complication of high-dose cytosine arabinoside.