Not the usual sinusitis.

An encephalocele is a protrusion of the cranial contents beyond the normal confines of the skull. It is a rare cause of seizure in adults. A 38-year-old woman presented with a first-onset seizure. Brain CT was interpreted as right frontal sinus opacification suggestive of sinusitis. The patient was discharged home with an amoxicillin prescription. A few days later, she was re-admitted with another seizure. Careful evaluation of the brain CT and MRI revealed a right frontal sinus posterior wall defect and possible brain encephalocele. The patient had complained of chronic nasal discharge for years and had also noticed a watery discharge from her right nostril. We suspected cerebrospinal fluid rhinorrhea. A bifrontal craniotomy was performed, the encephalocele was resected and cranialisation of the frontal sinus was completed. The patient remained free of seizures at the last follow-up.