DELAYED, TRANSIENT ENCEPHALOPATHY AFTER MARROW TRANSPLANTATION - CASE-REPORTS AND MRI FINDINGS IN 4 PATIENTS

Subacute encephalopathy developed in four patients within one to two m onths after undergoing high-dose chemotherapy and bone marrow transpla ntation or peripheral blood progenitor (stem) cell transplantation for breast cancer, acute myeloid leukemia, and non-Hodgkin's lymphoma. No ne of the patients had previously known neurologic disorders, central nervous tumor or infection. Two patients presented with generalized to nic, clonic seizures, and two with confusion and lethargy. In all pati ents lumbar puncture and CT scans of the brain were normal, while magn etic resonance imaging (MRI) demonstrated multifocal predominantly whi te matter lesions. Phenytoin therapy was given to the two patients wit h seizures and all four patients improved without specific therapeutic intervention. Repeat MRIs became normal within three months. We repor t a delayed and transient encephalopathy which appears to be a unique complication of high-dose cytotoxic chemotherapy. The corresponding br ain lesions may not be appreciated on CT scans, suggesting an expanded role for MRI studies in patients who develop neurologic findings whil e undergoing high-dose cytotoxic therapy.