Comparison of Pathologic Findings of Cortical Lobectomy for Intractable Seizures between Children and Adults: An Analysis of 164 Cases

Kim, Na Rae; Suh, Yeon Lim

Abstract

Many pathological surveys of brain tissue in patients with intractable epilepsy have been reported. There have been, however, few studies focused on the differences between childhood and adults in pathological alterations of brain. We retrospectively analyzed histopathology of 164 lobectomy specimens for intractable epilepsy in view of the differences between children and adults. Among 164 cases, 28 cases were children (less than 15 years) and 136 cases adults. We compared frequency of histopathologic features, distribution of involved cortex (temporal or extratemporal lobe), previous injury histories, such as brain trauma, encephalitis or febrile seizure, and coexistence of other lesions (dual pathology) between two groups. Pathologic alterations were encountered in 92% of 164 patients. In children focal cortical dysplasia (n=16, 57.1%), neoplasm (n=8, 28.6%), hippocampal sclerosis (n=6, 21.4%), cortical tuber (n=1, 3.6%), leukomalacia (n=1, 3.6%), and Rasmussen's encephalitis (n=1, 3.6%) were observed, whereas focal cortical dysplasia (n=81, 59.6%), hippocampal sclerosis (n=80, 58.8%), neoplasm (n=19, 14%), and cerebral cysticercosis (n=3, 2.2%) were found in adults. Pediatric patients had a higher proportion of severe focal cortical dysplasia (17.9% in children, 0.7% in adults). Neoplasia and extratemporal lobe involvement were more commonly found in children (28.6%, 50%) than in adults (14.0%, 24.3%), whereas hippocampal sclerosis and dual pathology were more common in adults (58.8%, 44.9%) than in children (21.4%, 17.9%). Previous injury history was statistically significant in patients with hippocampal sclerosis, and lent support to the hypothesis that hippocampal sclerosis is related with acquired lesions. Incidence of focal cortical dysplasia was nearly similar in both adult (59.6%) and pediatric groups (57.1%), and supported the hypothesis that focal cortical dysplasia is developmental abnormality occurring during a prenatal period.