Pulsatile tinnitus: a review of the literature and an unusual case of iatrogenic pneumocephalus causing pulsatile tinnitus.

摘要

BACKGROUND: Pulsatile tinnitus is frequently attributed to identifiable and treatable causes, in contrast to the more common subjective non-pulsatile tinnitus. It usually originates from vascular structures as a result of either increased blood flow or lumen stenosis; atherosclerotic carotid or subclavian artery disease; arterial, venous, or arteriovenous malformations, fistulas, or dissection; and paragangliomas. Other causes have also been reported, with often unclear pathophysiology. OBJECTIVE: The aim of this paper is to present a case of pulsatile tinnitus secondary to iatrogenic pneumocephalus and to review the literature on pulsatile tinnitus. SUBJECT: A 48-year-old white woman had a roaring, very disturbing, pulsatile tinnitus after the removal of a cerebellar lobe meningioma. When the patient experienced the symptom of tinnitus, a pulsatile movement of the tympanic membrane could be clearly seen, and this was synchronous with the patient's heartbeat. Computed tomography revealed an epidural pneumocephalus in the left posterior fossa communicating freely with the air cell system of the left mastoid cavity without any sign of residual tumor. A simple mastoidectomy was performed. The whole air cell system was removed and the mastoid cavity was filled with abdominal fat. After the operation, the pulsatile tinnitus ceased completely and the pneumocephalus disappeared gradually. The patient is free of symptoms 11 months after surgery. CONCLUSION: Otologists, neurosurgeons, and skull base surgeons should be aware of this surgical complication and be careful to identify any accidental opening to the air cell system of the temporal bone and meticulously close it when it happens. The review of the literature leads to the conclusion that pulsatile tinnitus should be thoroughly investigated, as it may be related to diseases that may have serious complications.