前庭及半规管轻度发育异常致眩晕的临床上特点

目的 探讨前庭及半规管轻度发育异常畸形所致眩晕的临床表现特点及可能的病理生理机制.方法 回顾性分析中山大学附属第三医院内耳病门诊的5例最终确诊为前庭扩大伴水平半规管畸形所致眩晕患者的病史特点、眩晕发作特点与持续时间以及听功能、前庭功能与影像学特点.结果(1)病史特点:4例幼年时有粗大运动发育延迟及潜在的平衡功能不良,1例无法提供幼时病史,成年后可长期保持听及前庭功能正常.(2)首次眩晕发作多能提供导致颅压或腹压骤然增高的诱因,如头部被撞击,用力擤鼻、便秘等.(3)发作性眩晕、渐进性听力下降等临床表现类似梅尼埃病及大前庭水管综合征,但眩晕持续时间不符合梅尼埃病特征,而听力下降程度及听力曲线类型有别于梅尼埃病及大前庭水管综合征.(4)部分患者眩晕与体位有关,但体位诱发试验结果不符合良性阵发性位置性眩晕特征.(5)影像诊断提示前庭扩大伴水平半规管轻度发育异常.结论 前庭扩大伴水平半规管发育不良是耳源性眩晕的少见病因,幼年时粗大运动发育延迟及平衡功能不良病史、听功能、前庭功能及影像检查可明确诊断.

Vertigo due to enlarged vestibule with lateral semidrcular canal dysplasia: an analysis of clinical characteristics

Objective To explore the clinical characteristics and possible pathological mechanisms of vertigo due to enlarged vestibule with lateral semicircular canal dysplasia.Methods A retrospective review was conducted for 5 cases of peripheral vertigo due to enlarged vestibule with lateral semicircular canal dysplasia.Their characteristics of medical history,precipitating factors,course of vertigo,auditory tests,vestibular tests and imaging examine results were analyzed.Results The clinical characteristics were as follows.(1)Specifics of medical history:4 cases suffered delays in gross motor development and potential equilibrium dysfunctions.One case failed to recount an earlier medical history,but could maintainnormal hearing and vestibular functions for a long time in adulthood.(2)Most cases could identify the precipitating factors of initial attacks,such as head-bumping,nose-blowing and constipation,etc.resulting in sudden rises of intracranial or abdominal pressures.(3)Paroxysmal vertigo and progressive hearing loss were mimicking Meniere disease or large vestibular aqueduct syndrome.But its course of vertigo was different from those of Meniere disease and large vestibular aqueduct syndrome with regards to hearing levels and audiograms.(4)Some cases had positional vertigo.But the results of Dix-Hallpike and Roll tests were different from benign paroxysmal positioning vertigo(BPPV).(5)The inner ear imaging showed enlarged vestibule with lateral semicircular canal dysplasia.Conclusion The enlarged vestibule with lateral semicircular canal dysplasia is a rare etiology of peripheral vertigo.The history of delays in gross motor development and potential equilibrium dysfunctions in childhood may offer important diagnostic clues.And audiological and vestibular tests,high-resolution computed tomography and magnetic resonance may help to ascertain the diagnosis.