Value of EEG in childhood acute lymphoblastic leukemia.

The EEG was recorded in 110 patients with acute lymphoblastic leukemia at the time of diagnosis, in 25 at the time of relapse and in 62 patients at discontinuation of treatment. At the time of diagnosis the EEG was abnormal in 60% of the patients. The abnormality showed no correlation with the prognosis. The EEG was correlated with the leukocytosis of the CSF and with the immunologic cell type of the leukemia. At the time of relapse the EEGs did not differ from those obtained at the time of diagnosis. No specific features distinguished the EEGs of the patients with CNS relapse. At discontinuation of treatment the EEG was abnormal in 31% of the patients. The EEG was not correlated with the method of CNS prophylaxis. Thus, it seems that the usefulness of electroencephalography in leukemic patients lies mainly in the diagnosis of neurologic complications.