Acoustic neuroma or vestibular schwannomaz or neurolemmomas is a noncancerous growth which occurs on the 8th cranial nerve. It is also known as acoustic nerve, or auditory nerve, or vestibulocochlear nerve. It is a composite nerve supplying the hair cells of the vestibular organ and the hair cells of the cochlea.
Acoustic neuromas commonly develop slowly for many years. They don’t infringe brain but can push it as they expand. The cranial nerves that manage facial expression and sensation muscles can be pressed by big tumors. Still, if they get big, they can press brain stem or cerebellum which can be fatal.
Acoustic Neuroma Symptoms
Early symptoms are insidious. It’s mostly misunderstood as aging symptoms. Hence acoustic neuroma is most of the times known only after diagnosis. (1)
- Gradual loss of hearing
- Tinnitus (a ringing or booming sensation in one or both ears)
- Sudden loss of hearing
- Persistent or reoccurring facial numbness and tingling
- Facial fragility
- Taste modifications
- Problem in swallowing
- Stiffness or irregularity
Acoustic Neuroma Causes
Sporadic form of acoustic neuroma occurs majorly but its cause is unknown. While, neurofibromatosis type II (NF2) accounts for 5% of acoustic neuromas and is inherited. Noncancerous tumors grow in the nervous system. By age 30, it commonly occurs in both ears. High exposure to radiation is a risk factor of acoustic neuroma. (2)
Acoustic Treatment courses
Also named as “watchful waiting”, as cancer grows slowly. Doctors usually observe tumor with regular MRI scans and will decide suitable treatment in case of the large growth of the tumor and chronic symptoms.
Either whole or a part of the tumor is removed. (3)
Surgery approaches include:
An incision is made behind the ar and the bone from it and bone from some part of the middle ear is removed. Before the tumor is removed, the doctor checks the crania nerve. But, this technique results in permanent deafness.
The skull near the back of the head is opened. This procedure removes big tumors and prevents hear loss.
A tiny piece of bone above the ear canal is removed to view and remove tumors present in the internal auditory canal. This procedure can protect hearing.
Total Endoscopic Resection
It is a latest less invasive procedure in which acoustic neuroma is removed with a tiny camera which is inserted via a hole in the skull.
Sometimes this progressive delivery procedure is used for acoustic neuroma. High doses of radiation are sent to tumor keeping the adjacent tissues safe. (4)
It is done in 2 ways:
- Single fraction stereotactic radio surgery (SRS): Hundreds of radiation beams are pointed to tumor in one session.
- Multi session fractionated stereotactic radiotherapy (FRS): small doses of radiation are delivered daily for many weeks. It’s said to be better than SRS in preserving hearing. (7)
These techniques don’t need hospitalization. These kill the tumor. The growth is either slowed down or stopped but doesn’t remove the tumor completely.
Factors affecting treatment selection (6)
- Tumor size
- If the tumor is growing or not
- Other ailments
- The intensity of symptoms and its effect on routine
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