Question: Illinois Subscriber Answer: A tegmen defect can lead to cerebrospinal fluid leakage through the ear's structures. Many of the leaks are postoperative and are recognized as a potential complication of acoustic neuroma surgery. The fluid might leak from the ear if the patient's eardrum or external ear canal is damaged, but might also flow down the Eustachian tube. Physicians must differentiate leakage from a tegmen defect from a spinal fluid leak from other areas of the skull base, such as the sinuses.