Symptoms and Diagnosis
The most typical first symptom of acoustic neuroma is slowly progressive hearing loss in one ear, frequently accompanied by ringing in the ear (tinnitus). Because it arises from the balance nerve, mild unsteadiness or dizziness may also appear over time; as the tumor grows, facial numbness or, rarely, weakness in facial movements can occur. One-sided hearing loss must always be assessed with audiometry (a hearing test), and where there is suspicion a contrast-enhanced thin-slice MRI should be performed — this is the basic investigation that establishes the diagnosis and shows the tumor’s size and relationship to the brainstem. Early diagnosis is valuable both for preserving hearing and for allowing less invasive options.
Three Paths: Observation, Surgery, Radiosurgery
There is no single correct treatment in acoustic neuroma; three main approaches are chosen according to the patient. The first is observation (wait-and-see): for small, asymptomatic tumors or in older patients, growth is followed with regular MRI — because some of these tumors do not grow significantly for years. The second is microsurgery: an operation performed behind the ear to remove the tumor, coming to the fore especially in large tumors or those pressing on the brainstem. The third is Gamma Knife / stereotactic radiosurgery: a method requiring no incision, aimed at stopping the tumor’s growth, which can be preferred for small-to-medium tumors. Which path is chosen is determined by the tumor’s size, growth tendency, current hearing and the patient’s general condition.
Preserving the Facial Nerve and Hearing
The real skill in surgery for this tumor lies less in removing it than in protecting the facial nerve right beside it and, where possible, hearing. The facial nerve governs all facial movements, from closing the eye to smiling; for this reason continuous nerve monitoring (neuromonitoring) is used during surgery to track the nerve’s position in real time and try to protect it. Whether hearing can be preserved depends largely on the pre-operative hearing level and the tumor’s position; in some cases hearing can be preserved, in others it may not be possible. These facts are discussed openly with you when deciding which approach to choose — because the balance between “removing the tumor” and “preserving function” is everything in this disease.
The Process and Recovery
In patients chosen for observation the process consists of regular MRI and hearing tests; intervention arises only if growth or increasing symptoms occur. Microsurgery is performed under general anesthesia, can take several hours depending on the tumor’s size, and usually involves a recovery period following a few days’ hospital stay; balance symptoms such as dizziness begin to be compensated by the brain in the first weeks. Gamma Knife is done in a single session without an incision and the patient mostly returns home the same day; however its effect (the halting of tumor growth) is assessed over months with follow-up MRI. Whichever path is chosen, regular follow-up with audiometry and MRI continues after treatment.
Honest Expectations
Acoustic neuroma is a benign tumor and, when managed correctly, long-term control is usually possible; the aim is often not to remove the tumor completely but to stop its growth and preserve function. However, no method can guarantee that hearing will be preserved or that no symptom will remain. The risks of surgery include temporary or permanent weakness of the facial nerve, reduced hearing, balance problems and, rarely, a cerebrospinal-fluid leak; with radiosurgery, facial-nerve effects or regrowth over the long term can rarely be seen. For this reason we determine the most suitable path for you realistically, together with your current hearing and your expectations.