To refer or not to refer…that is the question. As providers and audiologists, not only do we treat patients with hearing loss, we also must know when it’s appropriate to make a referral to an Ear, Nose and Throat specialist due to specific issues outside our scope of practice. Reasons for referrals may include completely impacted wax, fluid in the middle ear, sudden hearing loss due to possible virus or, the most severe, an acoustic neuroma (tumor). A hearing health professional’s worst fear (and I’m speaking for all) is missing an acoustic neuroma. Side effects of an undiagnosed acoustic neuroma can range anywhere from simple hearing loss on the affected side to death. That is why, as a team, we take our testing seriously and review our results very thoroughly with our patients.
An acoustic neuroma, aka vestibular schwannoma, is a (usually) benign, slow growing tumor that develops on the eighth cranial nerve, which travels from the inner ear to the brain. If the tumor grows rapidly and large enough, it can press against the brain and cause issues with vital functions. Normal flow of fluid between the brain and spinal cord could be compromised, which causes a build-up of fluid in the head (hydrocephalus). However, the most common symptoms reported are hearing loss (usually gradual) on the affected side, loss of balance, ringing in the ears (tinnitus) and facial numbness on the affected side. Patients should see a doctor or a hearing health professional if these symptoms are present.
There are few known risk factors. However, scientists believe that an acoustic neuroma can be caused by a faulty gene on chromosome 22. This gene helps control the growth of Schwann cells, which cover the eighth cranial nerve. This gene is inherited in a rare disorder called Neurofibromotosis Type 2, which involves the growth of tumors on balance nerves. One other possible risk factor is childhood exposure to low-dose radiation of the neck and/or head.
Certain testing will be conducted for a proper diagnosis, including a complete audiometric exam, a vestibular exam, and scans (i.e., MRI or CT) to confirm the presence of the acoustic neuroma. If a tumor is in fact discovered, and depending on the severity, a physician may recommend surgical removal, radiation or simply monitoring the growth. Certain surgical procedures can actually worsen the symptoms or create other serious issues such as leakage of cerebrospinal fluid, severe headaches, meningitis or stroke. For this reason, a physician may choose to monitor the tumor unless symptoms worsen. Regardless of the route of treatment, an early diagnosis for an acoustic neuroma is key and could prevent serious complications.