The acoustic nerve, also known as the auditory or vestibulocochlear nerve, is one of the cranial nerves. Cranial nerves are different from spinal nerves in that they originate directly from the brain instead of the spinal cord, as is commonly the case. The acoustic nerve assists the body with such functions as balance and hearing. Head position is also affected by the acoustic nerve.
There are two separate branches of the acoustic nerve, with each branch having its own set of responsibilities. The first branch is called the cochlear branch, or the cochlear nerve. This branch of the acoustic nerve carries signals to the brain from the portion of the inner ear known as the cochlea, a structure integral to the sense of hearing.
The vestibular nerve is the second branch of the acoustic nerve. This branch assists with the ability to hear, but it has other functions as well. The primary function of this nerve branch is to interpret positional signals related to the head. In addition to head position, the vestibular nerve is crucial to the sense of balance.
Nerve damage is possible in any area of the body, but damage involving the acoustic nerve has specific symptoms and consequences. This nerve damage can occur due to naturally occurring diseases or conditions. However, damage to this particular area of the body is more likely to occur due to some sort of traumatic injury.
Perhaps the most prevalent non-traumatic cause of damage to the acoustic, or auditory, nerve is a medical condition known as an acoustic neuroma. This is a non-malignant, or non-cancerous, tumor that develops on the nerve. Dizziness and hearing loss are the primary symptoms of this condition. Treatment generally involves either surgery or radiation to remove or dissolve the tumor.
Physical trauma, especially trauma involving the face and the head, has the potential to damage the acoustic nerve as well as the surrounding tissues and structures. There are specific symptoms that occur after this type of injury that can alert medical professionals to the need for further testing. Some common symptoms of this type of nerve damage include mild, moderate, or severe hearing loss as well as dizziness or other balance problems.
Tinnitus, or ringing in the ears, is often a sign that nerve damage could be a possibility. Vertigo is another condition that often coincides with the other symptoms of injury. Vertigo is a specific type of dizziness in which the patient still senses motion even when ceasing all movement. Treatment for any of these symptoms will depend on the type as well as the extent of the injury. While surgery is often required in order to repair damaged nerves, mild injuries may require little to no medical intervention.