The vestibular nerve carries balance information from the inner ear to the brain. In some people, this nerve sends abnormal signals, causing disabling vertigo. A vestibular nerve section is a surgical procedure in which the balance branch of the eighth cranial nerve is cut, while the hearing branch is left intact. The goal is to stop vertigo attacks while preserving useful hearing in the affected ear.

Who May Benefit from the Procedure

This operation is usually considered when medical treatment fails to control vertigo. Common underlying conditions include Meniere’s disease, recurrent vestibulopathy, and some forms of vestibular neuritis. The ideal candidate has useful hearing in the affected ear and severe, unremitting dizzy spells that interfere with daily life. A thorough evaluation, including audiometry and imaging, is performed before surgery to confirm the diagnosis and assess the integrity of the inner ear.

Surgical Approaches

There are two widely used routes to access the vestibular nerve: the retrosigmoid approach and the retrolabyrinthine approach. Both are performed under general anesthesia and involve a small opening in the skull behind the ear.

Retrosigmoid Approach

The retrosigmoid approach exposes the nerve through an incision behind the ear, followed by a small craniotomy in the occipital region. The cerebellum is gently retracted to reach the internal auditory canal. The surgeon identifies the vestibular and cochlear branches under an operating microscope. The vestibular nerve is then divided, while the cochlear nerve is spared. This approach offers excellent visualization of the nerve complex and is associated with a high rate of hearing preservation. It may also be used for tumor removal if a growth is found during surgery.

Retrolabyrinthine Approach

The retrolabyrinthine approach reaches the internal auditory canal through the mastoid bone, passing posterior to the semicircular canals. It avoids retraction of the cerebellum, which may reduce the risk of certain headaches after surgery. The surgeon drills through the mastoid air cells and opens the dura behind the labyrinth. The vestibular nerve is then sectioned with careful monitoring of the cochlear nerve. Hearing preservation is generally good, though the risk of a cerebrospinal fluid leak may be slightly higher than with the retrosigmoid route. Both techniques are valid; the choice depends on the surgeon’s experience, the anatomy of the patient, and the presence of other ear pathology.

Intraoperative Monitoring

During either approach, the facial nerve is monitored with electromyography to reduce the risk of facial weakness. Hearing is monitored by recording auditory brainstem responses or electrocochleography. These tools allow the surgical team to adjust the dissection in order to protect both facial function and residual hearing. The use of a nerve integrity monitor is standard in modern vestibular nerve section procedures.

Risks and Complications

As with any intracranial operation, there are potential risks. These include infection, bleeding, stroke, and cerebrospinal fluid leakage. Specific risks for vestibular nerve section include hearing loss, facial nerve weakness, dizziness, tinnitus, and headaches. The chance of profound hearing loss varies by approach and by the underlying disease; in most large series, it is less than ten percent. Injury to the facial nerve is uncommon when intraoperative monitoring is used. Many patients experience temporary imbalance after surgery, but the brain gradually compensates for the loss of input from the operated ear.

Recovery and Outlook

Most patients stay in the hospital for two to four days after the procedure. The dressing around the incision is removed within a few days, and stitches or staples are taken out after about a week. Returning to work typically takes two to six weeks, depending on the physical demands of the job. During the first months, vestibular rehabilitation and balance exercises are important to improve gait and reduce disequilibrium. The success rate for controlling vertigo is high — most studies report complete or substantial control of dizzy spells in over ninety percent of patients. Hearing is often stable or slightly improved in the long term, though some patients may notice a slow decline related to their underlying ear disease rather than the surgery itself.

Summary

Vestibular nerve section is a powerful surgical option for patients with severe vertigo and useful hearing. Both the retrosigmoid and retrolabyrinthine approaches have favorable outcomes, and the choice of technique should be individualized. With careful patient selection, modern monitoring, and a skilled surgical team, the procedure can eliminate debilitating attacks while preserving hearing and facial function.