Acoustic neuroma is another name for vestibular schwannoma, a benign tumor that grows on the eighth cranial nerve. It relays information between the brain and inner ear. An acoustic neuroma can range in size from 1.5cm to as large as 6cm, according to MayoClinic.com. Even though the tumor does not progress to cancer, acoustic neuroma complications may affect some people.
Permanent Hearing Loss
The eighth cranial nerve, or vestibulocochlear nerve, has two functions: carrying sound and balance. MayoClinic.com points out that while most acoustic neuromas form on the part of the vestibulocochlear nerve responsible for balance, patients can develop hearing loss in the affected ear. While the National Institutes of Health website MedlinePlus notes that one-half of patients with small acoustic neuromas regain their hearing after surgery, some people may not. Larger acoustic neuromas may result in permanent hearing loss.
Hydrocephalus
MayoClinic.com explains that larger acoustic neuromas can push against the brainstem, disrupting the flow of the cerebrospinal fluid. The cerebrospinal fluid surrounds the brain, protecting the brain and transporting nutrients. The build up of cerebrospinal fluid causes a condition called hydrocephalus, which increases pressure on the brain. The National Institute of Neurological Disorders and Stroke points out that symptoms of hydrocephalus include headaches with vomiting, blurred or double vision, balance problems, nausea, urinary incontinence, poor coordination, irritability and memory loss.
Balance and Gait Problems
Acoustic neuromas affect a patient's balance and can produce vertigo, which is an abnormal sensation of movement. When patients are standing still, it may feel as if their environment is moving. MayoClinic.com notes that these balance problems can cause patients to have a clumsy gait, and they may fall or trip easily.
Facial Weakness and Numbness
Some acoustic neuromas can put pressure on nearby nerves, causing facial weakness and numbness, according to MayoClinic.com. Patients may have trouble moving their facial muscles and may lose feeling in their face. The facial sensation changes can remain even after tumor removal. MedlinePlus explains that about two-third of patients with large acoustic neuromas have permanent weakness after having surgery.
