Acoustic Neuroma
Background:
Signs & Symptoms:
- An acoustic neuroma, also known as vestibular schwannomas, is a benign tumor arising on the acoustic nerve (aka vestibularcochlear nerve) or cranial nerve eight, which carries information regarding balance and hearing to the mid-brain. The tumor commonly arises from the vestibular component of the cranial nerve but the etiology remains unknown. It has been estimated that approximately 95% of tumors are unilateral and sporadic in nature, growing approximately one mm per year (Moffat et al., 2012). Acoustic neuromas constitutes roughly 6% of intracranial neoplasms and occur in approximately 9-13 million people per year (Murphy and Suh, 2011).
Signs & Symptoms:
- The symptoms arise as the tumor compresses the surrounding cranial nerves and the brainstem as it expands through the internal auditory canal through the cerebellopontine angle (Stucken et al., 2012).
- Hearing loss (most common)
- Vertigo
- Tinnitus-usually unilateral and confined to the affected ear
- Disequilibrium
- Trigeminal Nerve (CN 5) dysfunction
- Headache
- Facial nerve (CN 7) dysfunction
- Diplopia (double vision)
- MRI
- Auditory brainstem response (ABR)
- Electrical brain activity is recorded via electrodes placed on the scalp.
- The brain activity is recorded in five waves and the uninvolved side is used for comparison (Fortnum, 2009).
- Larger tumors are easier to detect (Fortnum, 2009).
- Surgery
- Radiation
- Vestibular Rehabilitation (See treatment tab)