Blog

The symptoms of acoustic neuroma are directly related to the size and growth of the tumor. Clinicians should be vigilant for all patients with unilateral hearing or vestibular symptoms.Tumors in the internal auditory canal usually manifest as hearing loss, tinnitus, and vestibular dysfunction. After the tumor grows into the cerebellopontine angle, hearing is further decreased, and balance disorders may occur. When the tumor compresses the fifth cranial nerve, ipsilateral numbness may occur.The tumor grows further and oppresses the brainstem, hydrocephalus may occur, headaches and vision loss may occur.But about 15% to 20% of patients with acoustic neuroma may have atypical symptoms.

Unilateral sensorineural hearing loss is the most common symptom of acoustic neuroma, usually earlier than other symptoms, and the speech recognition rate is disproportionately reduced. Patients find it difficult to understand language especially when using the affected ear to call.About 26% of patients with acoustic neuroma present with sudden deafness, and about 1~2.5% of all patients with sudden deafness are finally diagnosed as acoustic neuroma. It should be noted that the recovery of sudden deafness does not rule out acoustic neuroma. possible.Tinnitus is the second most common symptom and can appear before hearing loss. Therefore, unilateral tinnitus should also be alert to the possibility of acoustic neuroma.

In addition to the auditory nerve, the trigeminal nerve is the most common condition in which other cranial nerves are affected, which manifests as facial numbness, pain or paresthesia. Facial numbness usually first appears in the maxillary area, and the corneal reflex is decreased or disappeared during the examination, and facial pain and touch are decreased. There may be weakness or atrophy of the masticatory muscles and temporal muscles in the late stage.When the tumor is huge, symptoms of the posterior group of cranial nerves may appear, such as dysphagia, hoarseness, or coughing when swallowing.

Headaches are mostly occipital discomfort, tingling or dull pain at the beginning. As the disease progresses, the headache gradually worsens. When hydrocephalus and intracranial hypertension occur, severe headaches, nausea, and vomiting may occur. In severe cases, brain herniation may lead to death.Ocular symptoms are less common, manifested as diplopia or blurred vision. Diplopia is caused by the involvement of the abductor nerve, and blurred vision is caused by nystagmus or papilledema.Cerebellar dysfunction can be caused by compression of the cerebellum, manifested as coordinated movement disorder, unstable gait, and dumping to the affected side.

电生理测试包括听觉脑干反应（ABR）、耳蜗电图（EcochG）和耳声发射（OAE）。ABR是目前检测听神经瘤最敏感的听力学方法。ABR检查时，通常出现5个波形，其中以I、III、V波最明显，而波V最重要。正常波V潜伏期为5.4ms，两耳波V潜伏期差在0.2~0.4ms之间。听神经瘤患者波V潜伏期明显延长，超过6ms，两耳波V潜伏期差超过0.4ms以上。在部分高频听力尚在60dB以内的听神经瘤患者，亦可出现波形分化差或分辨不出。