Theophylline-associated seizures and their clinical characterizations

BACKGROUND: To elucidate the basic mechanism of theophylline-associated seizures (TAS), the clinical symptoms, electroencephalogram (EEG) and neuroradiological imaging of eight pediatric patients were all retrospectively evaluated. METHODS: Patients whose seizures represented their first episode were selected, while patients with cerebrospinal fluid abnormalities including pleocytosis and protein elevation, present illness of head trauma, epilepsy, febrile convulsion or any psychomotor retardation were excluded although they were given theophylline. RESULTS: Eight patients, 3.5 +/- 1.7 years of age, thus fulfilled the definition of TAS in the past 5 years. Based on their seizure patterns, EEG findings, brain single-photon emission computed tomography and head magnetic resonance imaging, a total of seven of eight patients had either localized or unilateral dominant lesions. They all had fever, > or =38 degrees C, and six of eight patients had a family history of febrile convulsions and/or idiopathic epilepsy. Thereafter none of them had convulsions after the cessation of theophylline administration. Through the TAS event, a 6-year-old female patient was found to have a right deep lateral cerebral venous angioma. CONCLUSION: In infants with idiopathic low seizure threshold and fever, theophylline administration might possibly trigger a seizure. Moreover, based on these patients' clinical findings, some kind of cerebral vascular involvements is speculated to be related with TAS.