Amy J. Litterini
© 2017 Joel Harrison
An acoustic neuroma, also known as a vestibular schwannoma, is a benign and slow growing primary intracranial tumor that originates from Schwann cells of the vestibular nerve within the inner ear. It is estimated that acoustic neuromas occur in 10-20 individuals per 1,000,000 annually in the United States. The tumor itself is often treated through surgical removal; however, the tumor and subsequent surgery frequently lead to vestibular nerve impairment. The vestibular nerve transmits sensory information to the brain from the peripheral vestibular system of the inner ear. Damage to one of the vestibular nerves may lead to vestibular dysfunction on the ipsilateral side, known as unilateral vestibular hypofunction (UVH). The peripheral vestibular system coordinates head and eye movement in order to maintain visual focus through the vestibulo-ocular reflex (VOR), helps maintain postural stability, and provides information used for spatial orientation. Impaired vestibular function may thus result in complaints of dizziness, postural instability, and oscillopsia, or visual blurring with head movement. Appropriate treatment of vestibular dysfunction is important, as dizziness is a major risk factor for falls. Ideally, vestibular rehabilitation through physical therapy (PT) is initiated immediately following recognition of vestibular dysfunction in order to help resolve symptoms. Common outcome measures are used to assess one’s level of VOR impairment through visual acuity and gaze stability tests, such as the Dynamic Visual Acuity test (DVAT) or the Rapid Head Thrust test (HTT). Nystagmus, defined as rapid and involuntary eye movements, may be observed during VOR assessment and is a primary indicator used in identifying vestibular lesions. Other outcome measures may also assess postural stability with static standing and dynamic gait tests through altering conditions for sensory input, such as with the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB). Additionally, it is important to assess a patient’s perception of their level of disability, such as through the Dizziness Handicap Inventory (DHI). Treatment for vestibular dysfunction is based on the principles of VOR adaptation, postural stability, and habituation. While there is moderate to strong evidence supporting vestibular rehabilitation in the management of patients with vestibular dysfunction, including UVH, it is important that treatment be individualized to target the patient’s specific impairments. Vestibular rehabilitation is well supported by literature for patients with acute UVH immediately following surgical removal of an acoustic neuroma. Additionally, there is strong evidence supporting the use of vestibular rehabilitation for patients with chronic symptoms of UVH in general lasting greater than two months. However, there is little evidence supporting the use of vestibular rehabilitation for patients with chronic symptoms of UVH, specifically post-surgical removal of an acoustic neuroma. Therefore, the purpose of this case report is to describe the outpatient PT management of a patient with chronic symptoms of UVH three months after surgical removal of an acoustic neuroma.
Harrison, Joel, "Outpatient Vestibular Rehabilitation For A Patient Three Months Post Acoustic Neuroma Resection: A Case Report" (2017). Case Report Papers. 73.