The VIII nerve, also known as the vestibulocochlear nerve or the acoustic nerve, is the eighth of twelve cranial nerves. It is a sensory nerve that carries information from the inner ear to the brainstem. The VIII nerve is responsible for both hearing and balance.
What is the cranial nerve?
The VIII nerve is a very important nerve that is responsible for both hearing and balance. Damage to this nerve can cause hearing loss, balance problems, or both. If you experience any problems with your hearing or balance, it is important to see a doctor to get an evaluation.
What is the function of the VIII nerve?
The VIII nerve has two functions: hearing and balance.
- Hearing: The cochlear nerve, which is part of the VIII nerve, carries signals from the cochlea, which is the hearing organ in the inner ear. The cochlea converts sound waves into electrical signals, which are then sent to the brain by the cochlear nerve.
- Balance: The vestibular nerve, which is also part of the VIII nerve, carries signals from the vestibular system, which is the balance organ in the inner ear. The vestibular system is responsible for detecting movement and orientation of the head, and it helps to maintain balance.
How do you assess cranial nerve VIII?
There are a number of ways to assess cranial nerve VIII. Some of the most common tests include:
- Pure-tone audiometry: This test measures the softest sounds that a person can hear at different frequencies.
- Speech audiometry: This test measures how well a person can understand speech at different volumes and frequencies.
- Vestibular testing: This test measures the person’s ability to maintain balance and their response to changes in head position.
Is cranial nerve VIII motor or sensory?
The VIII nerve is a sensory nerve. It carries signals from the inner ear to the brainstem, but it does not send any signals from the brainstem to the inner ear.