Biedert S, Weidauer H, Reuther R
Nervenarzt. 1985 Oct;56(10):535-42.
Tinnitus and vertigo, two common neurological complaints, often challenge the physician's ability with respect to possible etiology. Objective tinnitus can result from an abnormally patent eustachian tube, from tetanic contractions of the muscles of the soft palate, or from vascular abnormalities within the head or neck. Subjective tinnitus refers to lesions involving the external ear canal, tympanic membrane, ossicles, cochlea, auditory nerve, brainstem, and cortex. As many as 50% of patients with tinnitus do not exhibit associated hearing loss; in these patients, the cause of the tinnitus is rarely identified. An illusion of movement is specific for vestibular system disease--a peripheral or central location depending upon associated audiologic and neurologic symptoms, respectively. However, a presyncopal, light-headed sensation is most commonly associated with diffuse cerebral ischemia: in the young patient, this may be caused by a hyperventilation syndrome; in the aged individual, this can result from diffuse atherosclerotic cerebrovascular disease and decreased cardiac output. Postural and gait imbalance associated with acute vertigo indicates a unilateral peripheral vestibular or a central vestibular lesion; if vertigo is absent, either a cerebellar, proprioceptive, or bilateral peripheral vestibular lesion is likely. Transient oscillopsia suggests unilateral peripheral vestibular lesions. Permanent oscillopsia indicates a bilateral peripheral vestibular lesion or--in the absence of severe vertigo--brainstem or cerebellar damage.
耳鸣和眩晕是两种常见的神经科症状，常常对医生判断可能的病因构成挑战。客观性耳鸣可由咽鼓管异常通畅、软腭肌肉强直性收缩或头颈部血管异常引起。主观性耳鸣指涉及外耳道、鼓膜、听小骨、耳蜗、听神经、脑干和皮层的病变。多达50%的耳鸣患者不存在相关听力损失；在这些患者中，耳鸣的病因很少能被确定。运动错觉是前庭系统疾病的特征——根据相关的听力学和神经学症状分别定位于外周或中枢。然而，晕厥前的头晕感最常与弥漫性脑缺血相关：在年轻患者中，这可能由过度通气综合征引起；在老年个体中，这可能是弥漫性动脉粥样硬化性脑血管疾病和心输出量减少所致。与急性眩晕相关的姿势和步态失衡表明存在单侧外周前庭或中枢前庭病变；如果没有眩晕，则可能是小脑、本体感觉或双侧外周前庭病变。短暂性视振荡提示单侧外周前庭病变。永久性视振荡表明存在双侧外周前庭病变，或者——在没有严重眩晕的情况下——脑干或小脑损伤。
