Local brain herniation after partial membranectomy for organized chronic subdural hematoma in an adult patient: case report and review of the literature.

Objective: Local brain herniation after removal of chronic subdural haematoma is extremely rare, especially in adult patients. This study reports a case of local brain herniation after partial membranectomy for organized chronic subdural haematoma. Case report: A 77-year-old man presented with dysarthria and dysphasia caused by local brain herniation of the right frontal lobe through a defect of the inner membrane. The herniated brain was detected by magnetic resonance (MR) imaging. The patient underwent a craniotomy to release the herniated and strangulated brain, which were consistent with the MR imaging findings. The patient recovered fully within 1 month after surgery. Conclusions: To date, five cases of brain herniation through the internal subdural membrane have been reported as complications of chronic subdural haematomas. All but one case occurred in the paediatric population. Urgent surgery should be performed, even if an adult patient suffers from local brain herniation, for preservation of brain function. This is the sixth reported case of brain herniation through a defect of the inner membrane and the second reported case in the adult population.