Vestibular schwannomas are benign tumors arising from the cells that form the covering of the vestibular nerves. It used to be called acoustic neuroma but the term vestibular schwannoma is more accurate and preferred.
Most cases are diagnosed in people aged between 30 and 60. A typical history is slowly progressively one-sided hearing loss and tinnitus. It can be accompanied by vestibular symptoms, typically imbalance and dizziness, but may include vertigo. Larger tumors may affect surrounding structures, and cause facial weakness, and headaches. Very rarely, if the tumor grows unchecked and compresses the brainstem, more severe and potentially life-threatening manifestations may occur; such situations are extremely rare since most people will get an MRI before the condition progresses that far.
It usually arises sporadically, but are associate with a genetic condition called neurofibromatosis type-2. Some have suggested a link to prior radiation, and possibly frequent cell phone usage but I am unaware of firm evidence of this link.
Hearing tests may indicate unilateral hearing loss. A brain MRI with gadolinium contrast is the gold standard for diagnosing a vestibular schwannoma.
Vestibular schwannomas are unpredictable. While typically very slow growing, they can remain dormant and not grow for many years, but can grow at a fast rate in some. The decision on which treatment option is best should be made with a neuro-otologist.
Due to the slow growing and benign nature of the tumor, most are observed with serial MRIs (repeated every 6 to 12 months). In older adults, vestibular schwannomas may not grow at all, and this approach is the best for very small tumors.
Surgery can be considered to control tumor growth, and preserve hearing and the function of other cranial nerves. Stereotactic radiation can also be considered to control tumor growth.