Predictors of hippocampal, cerebral, and cerebellar volume reduction in childhood epilepsy

Purpose: We examined the factors related to brain volume reduction in a ped iatric sample of patients that included those with nonintractable epilepsy. Methods: Entry criteria were children less than 18 years old with epilepsy referred for MRT, including a whole brain volumetric sequence. The sample s ize was 231. Risk factors were ascertained from interviews and reviews of m edical records. Factors included age of onset, seizure years, family histor y, status epilepticus, intellectual disability, and febrile convulsions. MR T data were obtained for 44 normal childhood control subjects. Results: Cerebral and cerebellar volumes were significantly associated with age, gender, moderate-to-severe intellectual disability (p < 0.001), seizu re years, and status epilepticus (p < 0.03). Compared with controls, the br ain volume of all patients was reduced by 10% (p < 0.001). Hippocampal volu me was significantly associated with total brain volume, age (p < 0.001), f ocal cerebral ischemic injury, and complex febrile convulsions (p < 0.05). Conclusions: Significant brain volume reduction is present in children with epilepsy. A component of this reduction is due to acquired insults. The re duction is seen even in children with infrequent seizures over a brief time , suggesting an innate structural abnormality. When evaluating possible eti ologic factors in the development of hippocampal volume reduction, one must control for total brain volume. We have confirmed the association of compl ex febrile convulsions with unilateral hippocampal volume reduction.