Serial Spectral EEG Analysis in Children Treated with Intermediate-dose Methotrexate (ID-MTX)

Abstract

Serial spectral EEG analysis in eight children with acute leukemia and non-Hodgkin's lymphoma was performed to investigate the influence of intermediate-dose methotrexate (ID-MTX) on the central nervous system (CNS). The EEGs, recorded before and 24h or 48h, one week and a few months after administration of ID-MTX, were analyzed as to the power average spectrum of the occipital basic activity using an ATAC-450 (NIHON KOHDEN). Although there was no patient whose serum and cerebrospinal fluid MTX-concentration exceeded the upper therapeutic limit, a transient but statistically significant slowing, such as about 0.7 Hz drop in the dominant frequency, was observed at 48 hours after the initiation of ID-MTX. No neurological symptoms were noted, and these data suggest that EEG alterations might be a reflection of subclinical CNS impairment. Therefore, serial EEGs might be a good early indicator for the detection of CNS impairment in children treated with ID-MTX.