Imaging of carotid artery-cochlear dehiscence. A cause of pulsatile tinnitus

This study was conducted on 8 adult patients. The dehiscences ranged between 0.7 and 1.7 mm (average 1.04 mm). Two male patients showed bilateral dehiscences together with excessive pneumatization of both petrous apices. Six female patients showed only unilateral dehiscences. In the controls, the internal carotid artery to cochlea (ICA/Ch) distance ranged from 0.59 mm to 3.1 mm and was 1.618 mm in average. The dehiscences were more common in female. However when they occur in males, they tend to be bilateral and seems to be predisposed by excessive pneumatization of both petrous apices.