Severe permanent encephalopathy in acute lymphoblastic leukemia.

As survival rates for childhood acute lymphoblastic leukemia have increased, concerns over improved quality-of-life have also increased. Although 3-10% of children may experience acute transient neurotoxicity during induction chemotherapy, they are felt to be at low risk for late sequelae. We report three previously healthy boys with newly-diagnosed acute lymphoblastic leukemia who presented with obtundation and severe seizures during late induction with a standard four drug chemotherapy regimen. While all three are disease-free survivors, they unexpectedly have persistent and medically intractable partial complex seizures, broad-based neuropsychological impairment and striking neuroimaging abnormalities. These findings suggest that children with leukemia who develop an acute encephalopathy during induction chemotherapy are at risk for long-term neurological and neuropsychological sequelae, despite the cessation of further potentially neurotoxic therapy.