Burrell
Honors Anatomy Physiology
Fall Semester
Acoustic Neuroma. Something I’ve never heard of, you probably have. The eighth cranial nerve, which will be referred to as the auditory nerve for simplicity, consists of the cochlear and vestibular divisions. These two divisions, running from the inner ear to the brain, are responsible for transmitting information about hearing and maintaining balance, respectively. When the Schwann cells (used to keep peripheral nerve fibers alive) that surround the vestibular division grow at an abnormal rate inside if the ear canal, you’ve got yourself a case of acoustic neuroma.
The resulting tumor from the uncontrolled growth of cells is benign, meaning
that it isn’t cancerous (which would be malignant). Benign tumors grow only in one spot, do not spread or “invade” other parts of your body, and do not usually grow back after treatment.
Despite their lack of a cancerous nature, they are still dangerous because of their potential to grow and press upon viral organs, like the brain.
The tumors associated with acoustic neuroma normally grow slowly, and
because of this they symptoms associated with them develop gradually and can easily be over looked. The tumor presses against the auditory nerve, causing dizziness, hearing loss, and a “ringing in the ears” (tinnitus). If the tumor continues to grow and is allowed to get large enough, it will eventually press upon the nearby facial nerve and cause facial paralysis or tingling. The real danger of acoustic neuroma tumors is when they get even larger and press upon brain structures, particularly ones that control vital body functions. Other common
symptoms of acoustic neuroma include problems with balance, vertigo, taste changes, difficulty swallowing and hoarseness, and confusion.
There are two causes of acoustic neuroma: a sporadic form and the NF2
(neurofibromatosis type 2). The second of the two, NF2, is an