REVERSAL OF CNS-PROPHYLAXIS-RELATED LEUKOENCEPHALOPATHY AFTER CSF SHUNTING - CASE-HISTORIES OF IDENTICAL-TWINS

We report the case histories of identical twin brothers who developed concordant acute lymphoblastic leukemia at the age of 4 years and who later developed leukoencephalopathy and hydrocephalus related to centr al nervous system prophylaxis by, in the first case intrathecally admi nistered methotrexate and, in the second by intrathecally administered methotrexate and cranial irradiation. The delayed encephalopathy deve loped 9 and 22 months respectively after the first dose of intrathecal methotrexate. Both patients underwent cerebrospinal fluid shunting ma inly for their hydrocephalus. The imaging studies have shown that both hydrocephalus and leukoencephalopathy have improved significantly aft er ventriculoperitoneal shunt insertion. We review the pathophysiology of prophylaxis-related encephalopathy in leukemia patients and summar ize its clinical, histological, and radiological characteristics. We a lso discuss the possible contribution of altered cerebrospinal fluid d ynamics in the development of leukoencephalopathy.