原因不明一側性末梢前庭障害の検討

―内側型高位頸静脈球との関連―

抄録

　There are some cases of unilateral vestibular disorder without a confirmed diagnosis such as benign paroxysmal positional vertigo and Menière's disease. We performed a retrospective study to determine the cause of such unilateral vestibular disorders in patients. We investigated vertiginous outpatients who visited our clinic from Jan. 2011 to Feb. 2014. Eighty-nine patients were diagnosed as having unexplained unilateral vestibular disorders after equilibrium function tests. The diagnosis of a vestibular disorder is mainly facilitated by the demonstration of canal paresis with the caloric test. Temporal bone high-resolution CT was adapted in this study because we considered the possible presence of a unique anatomical feature of these patients.
　The patients showed a high rate of a high jugular bulb (HJB) with temporal bone CT findings compared to control cases. The medial type of HJB is significantly consistent with the affected side. In particular, all cases in which the jugular bulb diverticulum was observed and showed contact with the peripheral organs (vestibular aqueduct, cochlear aqueduct, posterior semicircular canal, and internal auditory meatus) in the image, were consistent with the affected side. The medial type of HJB was considered to be one of the anatomical predispositions related to vestibular disorder onset.