The enlarged vestibular aqueduct is more common in inner ear malformations, often combined with cochlear or vestibular malformations, but there are also those who present with simple enlarged vestibular aqueduct, the latter is called large vestibular aqueduct syndrome, mostly seen bilateral enlarged vestibular aqueduct. (1) History: Hearing loss, delayed speech development, sudden hearing loss, progressive or fluctuating hearing changes during the course of the disease, bilateral hearing loss is often asymmetric. It may be accompanied by episodes of vertigo. Some patients have a history of aggravation of deafness induced by shocks or trauma to the head. (2) Signs and symptoms: ① Deafness is mostly in early childhood. It is a progressive aggravation that appears later in life, often with fluctuating hearing loss, mostly bilateral. Hearing variability ranges from normal to very severe deafness, and severe cases may have speech impairment. ②About 1/3 of patients complain of vestibular symptoms, vertigo attacks with balance disorders and ataxia. 2. Auxiliary examinations ① Audiological examination: ① Pure tone audiometry: generally sensorineural deafness. ②Acoustic conduction resistance: to determine whether there are abnormalities in the middle ear. ③ABR, 40Hz AERP: applicable to uncooperative people and infants. (2) Vestibular function examination: nystagmography with low or no response to cold and heat realization. (3) Imaging: ① High-resolution thin-layer CT scan of temporal bone: axial CT scan shows the diameter of vestibular aqueduct, the maximum canal width >1.5mm at the midpoint between the common vestibular pedicle and the opening of vestibular aqueduct; horizontal semicircular canal or common pedicle level shows deep and large triangular obvious bone defect shadow at the posterior edge of rock valley; the triangular bottom is the anterior and posterior lip of the opening of vestibular aqueduct “bone defect shadow “The edge of the triangle is clear and sharp, and the internal opening is mostly in direct communication with the vestibule or the common pedicle. ② MRI of the inner ear: when the enlarged endolymphatic sac is found in the T2-weighted image, and there is a bar arc or ellipsoid on the surface of bilateral cerebellar hemispheres, the enlarged vestibular aqueduct should be noted. (2) Treatment principles: (1) When a rapid decline in hearing occurs, conservative treatment can be used to restore hearing as much as possible, so that the child can have a longer period of time to maintain a better hearing stage, which is beneficial to the child’s language development. (2) Generally, comprehensive treatment is used, mainly to improve the inner ear microcirculation metabolism and membrane permeability, commonly used low-molecular dextrose and geranium to improve inner ear microcirculation, also used prednisone or dexamethasone anti-inflammatory and anti-edema treatment, the course of treatment for several weeks. (3) Wear hearing aids for moderate to moderately severe hearing, and perform cochlear implantation for residual hearing as soon as possible for severe hearing or above. (4) Strengthen language rehabilitation training. (5) Prevent head trauma.