Paraparesis following intrathecal chemotherapy.

We studied a case of flaccid paraplegia that immediately followed intrathecal injection of cytosine arabinoside diluted in 1.5% bacteriostatic water (1.5% benzyl alcohol in H2O). The complication was reversed by rinsing the CSF space with saline. Autopsy showed fibrosis and remyelination of lumbosacral nerve roots. In acute and chronic animal experiments, we showed that benzyl alcohol in commercially used concentrations can have a local anesthetic and an irreversible toxic effect on nerve fibers. This provides a sufficient explanation for many cases of paraparesis following intrathecal chemotherapy.