The neurological, neuropsychological, and educational outcome in 14 children who received a second course of cranial radiotherapy or total body irradiation for relapsing lymphoblastic leukemia is reported from the Neurosciences Unit and Department of Haematology, Institute of Child Health, University of London. Nine (64%) had postirradiation somnolence syndrome characterized by lethargy, irritability, nausea, and vomiting. All patients had mild neurological deficits, including hyperreflexia, incoordination, dyspraxia, and hand muscle weakness. All were growth hormone deficient. MRI showed ventricular enlargements. Verbal comprehension and tests of attention and memory were impaired, girls showing greater impairments than boys. Of 9 children still at school, only 2 performed at age appropriate levels in reading, spelling, and math, and social outcome was poor. 
COMMENT. After survival of the rigors of two and three year protocols of chemotherapy for lymphoblastic leukemia, children who relapse after initial remission now have to face the prospect of postirradiation cognitive and neurological deficits. The morbidity asssociated with cranial radiotherapy has been recognized for some time, and the results of this study certainly favor the omission of presymptomatic irradiation and the use of intrathecal methotrexate in more current protocols. The justification for over-zealous treatments of relapsing leukemia in children needs re-evaluation in light of the long term adverse effects and the overall quality of life.