Abstract
A 19-year-old male patient with a history of congenital left oval window defect has had recurrent admissions to a children's hospital for bacterial meningitis since the age of 7. Investigations revealed a left-sided type 1 incomplete partition deformity of the left ear with a congenital oval window defect, leading to communication between the cranium and the middle ear. The patient underwent a left canal wall down mastoidectomy and oval window defect repair, remaining well for 3 years. He experienced two more episodes of bacterial meningitis as he got older, prompting repeated exploratory tympanotomy and repair of the cerebrospinal fluid (CSF) leak after each episode. Recently, he was referred again for recurrent meningitis. Investigations showed a recurrent oval window defect. After undergoing left external ear canal transection, mastoid and middle ear obliteration, and left Eustachian tube obliteration, he remained well without further leaks or meningitis. Congenital oval window defect is rare and may present with recurrent bacterial meningitis secondary to spontaneous CSF leak via the oval window. Radiology plays a crucial role in identifying the source of the CSF leak, facilitating more precise preoperative counseling and surgical intervention.