Brain herniation through an internal subdural membrane: a rare complication seen with chronic subdural hematomas in children

Abstract

The authors report an unusual case of cortical herniation into a chronic subdural hematoma (SDH). The patient was successfully treated with good outcome. A 4-month-old boy with a history of macrocrania and very large bilateral chronic SDHs underwent subduroperitoneal shunt treatment shortly after presentation. Eight months later he developed a new-onset seizure disorder, which was localized by electroencephalography to the right frontal region. Neuroimaging demonstrated the development of a focal herniation of the brain through a subdural membrane into the subdural space. The patient underwent a craniotomy to resect the seizure focus and the herniated cortex. The subdural shunt was subsequently replaced. After 2 years of follow-up, the patient remains free of seizures, is on no medication regimen, and is neurologically and developmentally normal. To the authors' knowledge, this is only the fourth report in the medical literature of cortical herniation through a chronic subdural membrane and the first in which successful treatment with a good outcome is described.