An acoustic neuroma (or Vestibular Schwannoma) is a benign, slow-growing tumour that originates in the canal connecting the brain to the inner ear, from the 8th cranial nerve. The 8th cranial nerve is actually two separate nerves, one associated with balance and the other with hearing; and the tumour can arise from the supporting cells (Schwann cells) covering the balance nerve as it passes from the inner ear to the brain stem.
Acoustic neuroma surgery
A benign slow-growing tumour
The 7th nerve, which services facial movement, also passes through this canal, as do important blood vessels. As these tumours expand, they begin to press on the hearing, balance and other nerves causing hearing loss, vertigo or tinnitus. They can then extend into the area at the base of the brain and press on the brain’s vital structures, which can be life-threatening. Rarely, these tumours can be part of a genetic condition called Neurofibromatosis.
Nevertheless, the majority of these tumours don’t grow, or glow slowly; and often they require observation only. However, if they grow at a rapid rate and/or are large and at risk of putting pressure on the brain, definitive treatment may be necessary which includes surgical removal of the tumour, or radiotherapy.
Sometimes other lesions presenting in the base of the skull can mimic the presence of an acoustic neuroma, such as other tumours or cysts but the majority of these lesions are benign and only need intervention if they are growing or compressing on other structures. Skull base lesions often need a multidisciplinary management such as involving the expertise of a neurosurgeon and/or a radiation oncologist.
