Unusual seizures with a benign course in a case of acute lymphoblastic leukemia of childhood

We report the unusual seizures in a patient with acute lymphoblastic leukemia. The convulsive disorder began acutely as partial somatomotor status epilepticus and with diffuse EEG slowing. The seizures then became myoclonic-atonic (drop attacks) and an EEG focus appeared on the left paramedian centro-parietal areas, activated by proprioceptive stimuli. Despite the severity of the clinical picture at onset, the seizures showed a benign course, and disappeared on carbamazepine therapy. We think that this epileptic syndrome may have been caused by diffuse iatrogenic encephalopathy, probably related to intrathecal methotrexate therapy.