This exhibit depicts the mechanism of brain injury during endoscopic sinus surgery. A sagittal view of the head illustrates the anatomy of the nasal cavity and its proximity to the brain. During endoscopic ethmoid sinus removal, the cribriform plate and dura are punctured with Takahashi forceps. This allows the brain to herniate through the cribriform plate defect and form an encephalocele. Repairs to the cribriform plate were performed with the application of septal graft and gelfoam.