Which cranial nerve is affected by vestibular schwannomas?

Vestibular schwannomas, also known as acoustic neuromas, specifically impact the eighth cranial nerve, which is the vestibulocochlear nerve. This nerve is responsible for transmitting sound and equilibrium information from the inner ear to the brain. Since vestibular schwannomas arise from Schwann cells that myelinate the vestibular portion of this nerve, they commonly lead to symptoms such as hearing loss, tinnitus, and balance difficulties.

The other cranial nerves listed do not have a direct relation to vestibular schwannomas. The fourth cranial nerve (trochlear nerve) is primarily involved in eye movement, particularly with the superior oblique muscle. The fifth cranial nerve (trigeminal nerve) is responsible for sensation in the face and motor functions such as biting and chewing. The sixth cranial nerve (abducens nerve) controls lateral eye movement. Therefore, recognizing the specific role of the vestibulocochlear nerve highlights why it is particularly affected by vestibular schwannomas.