Leukoencephalopathy induced by tegafur: serial studies of somatosensory evoked potentials and cerebrospinal fluid.

A case of leukoencephalopathy induced by tegafur, an antineoplastic derivative of 5-FU, is reported. The patient received 600 mg of tegafur p.o. for 16 days before excision of rectal cancer. After the operation, gait disturbance and mental abnormalities appeared. He became akinetic and mute within a few days following readministration of tegafur. Serial studies of brain CT, somatosensory evoked potentials (SEP) were made, and myelin basic proteins (MBP) in the cerebrospinal fluid were measured. The level of MBP was about twice the normal value and the central conduction time (CCT) of SEP was prolonged at admission. The value of MBP and CCT improved with recovery from akinetic mutism.