Abstract
Leukoencephalopathy is one of the most ominous complications of acute lymphoblastic leukemia in children under modern intensive treatments. During past 3 years, two of 31 children with ALL had developed typical leukoencephalopathy. The first case was seen in a 12-year-old boy, and 2nd case in a 4-year-old boy. The first one had died and the diagnosis was confirmed by autopsy. The extensive demyelinization, obliteration of axon, and necrotic areas were observed in the entire white matter. The calcification was also noted. The 2nd patient is now in the debilitated condition. The initial symptoms of leukoencephalopathy in those two cases appeared rather suddenly, after serial intrathecal instillation of MTX, CA and steroid, which was given in the combination for the second burst of CNS leukemia. Therapeutic cranial irradiation was also given in both cases for the first CNS leukemia. On CT scan, a distinct low density was seen over the area of white matter, when symptoms appeared.
As compared with 7 children, who had developed CNS leukemia, the intrathecal administration of MTX was carried out more frequently during shorter period, 25 times during 11 months in the first case and 24 times during 20 months in the second case.
From our limited experience, it was concluded that the dose and interval of intrathecal MTX administration might hold a major key for the development of leukoencephalopathy. The pharmacokinetic studies of MTX was thought to be mandatory, especially when it was administered intrathecally to the children at the time of cranial irradiation. It was also recommended to carry out periodical CT scan survey for the early diagnosis of leukoencephalopathy.
