Types of Post-Treatment Issues
- Balance Issues
Balance issues are very common with an acoustic neuroma, both pre- and post-treatment and they can be long or short term. These tumors are most accurately termed vestibular schwannomas because they arise from the sheath of the eighth cranial nerve or vestibulocochlear nerve which plays an important role in the body's balance system. For those who pursue surgery or radiation, the balance nerve may have been compromised, and it will take time to heal. If it was severed, the balance nerve on the other side of the brain can take over, but this does not happen immediately. Refer to the ANA patient information booklet - Improving Balance Associated with Acoustic Neuroma.
- CSF leaks
Cerebrospinal fluid, or CSF, is a watery fluid that flows in the ventricles (cavities) within the brain and around the surface of the brain and spinal cord. It is continuously produced and absorbed. On occasion, CSF leaks can happen after the microsurgical removal of an acoustic neuroma tumor. They can occur either through the nose or from the incision. Such leaks appear as a clear, watery discharge and can leave a salty taste in your mouth or a dripping feeling from your nose or from the incision. If left untreated, an infection that could lead to meningitis may follow, therefore these symptoms should be reported to your doctor immediately.
- Inability to Close Eyelid, Dry Eye, Double Vision
Because of its proximity to the 8th cranial nerve, the 7th cranial nerve and less often the 5th and 6th cranial nerves, all associated with eye function, may be affected in the removal of an acoustic neuroma. Difficulty blinking, excess moisture and/or excess dryness, double vision and eye sensitivity may occur. It is very important that the eye be artificially protected and it may be necessary to apply artificial tears or to tape the eye shut to allow for healing. In some cases, surgery on the eyelid is necessary. Refer to the ANA patient information booklet – Eye Care after Acoustic Neuroma Surgery.
- Facial Pain and Weakness
The 7th cranial nerve or facial nerve, is often affected in the treatment of an acoustic neuroma. The nerve may be damaged with either surgery or radiation, however it is usually possible to preserve some degree of facial function, even in cases where the nerve is extensively involved. Temporary weakness of the face due to nerve swelling is common and in some cases there may be permanent facial weakness. If the facial nerve is damaged, it is possible for it to regenerate slowly. It is also possible to reconnect the facial nerve during or after surgery. When it is not possible to repair the facial nerve additional surgeries may be necessary to substitute other nerves, allowing partial voluntary movement to return. To date, the most commonly used scale to rate the degrees of facial weakness is called the House Brackmann Scale. There are also many non-surgical options including exercises for patients with facial issues. Refer to the ANA patient information booklet – Facial Nerve and Acoustic Neuroma – Possible Damage and Rehabilitation.
- Taste and Swallowing Problems
It is not uncommon to experience dry mouth and taste disturbance for a few weeks following surgery. In some cases the duration is prolonged. If swallowing becomes a problem, a speech pathologist, nurse or occupational therapist can provide exercises to help move food down your throat.
Headache post-treatment can be caused by a variety of reasons. After surgical treatment for acoustic neuroma, the reported incidence of headache in the 2007-2008 ANA patient survey has ranged from 0% to 33%, depending on the type of surgical approach, the technique used and reporting interval since surgery. Frequent and severe post-operative headaches have been more often associated with the retrosigmoid/sub-occipital surgery approach than the translabyrinthine or middle fossa approaches. A variety of treatment options are available including additional surgery, drug therapy, exercise and some alternative options. Refer to the ANA patient information booklet – Headache Associated with Acoustic Neuroma Treatment.
- Hearing Loss
Hearing loss varies depending on the type of surgical approach. The translabyrinthine approach always results in hearing loss. With the other approaches there are prognostic factors that give some predictive outcome. Tumor size is not necessarily a predictor, however with larger tumors, the likelihood of preserving hearing is lower. Tumors originating from the superior vestibular nerve have a greater chance of hearing preservation than those arising from the inferior vestibular nerve. Those that do not extend all the way to the end of the internal auditory canal are more favorable for hearing preservation. Better preoperative hearing in general correlates with hearing preservation. Refer to the ANA patient information booklet – Hearing Loss – Rehabilitation for Acoustic Neuroma Patients.
A small percentage of patients will suffer from hydrocephalus, caused by an excessive accumulation of CSF in the brain. This condition is alleviated by an operation which places a "shunt" in the area to drain the fluid and relieve the excess pressure.
CSF leaks and infection following surgery are rare occurrences which can lead to meningitis if left untreated. Meningitis is inflammation or irritation of the meninges (fluid and tissue surrounding the brain). One causal factor that is particular to acoustic neuroma surgery is the drilling of bone from within the intradural space for further exposure of the tumor in the internal auditory canal. This process is nearly exclusive to the retrosigmoid approach and is much less common in the translabyrinthine or middle fossa approaches. The drilling often results in bone dust distributed around the meninges in the posterior fossa, which can be difficult to remove completely. Two studies have highlighted the importance of bone dust in inducing meningitis following AN surgery. If this condition occurs, it would require an extended hospital stay
- Regrowth of the Tumor
Recurring tumors can be caused by several issues and they do occur in a small percentage of acoustic neuroma patients. Sometimes a small part of the tumor is left in the brain during the first surgery. This may be intentional to preserve the facial nerve, or unintentional. Treatment options for the re-growth can be another surgery or oftentimes, patients consider radiation.
- Seizures, Strokes
A rare complication of acoustic neuroma surgery is the possibility of a stroke due to damage to major blood vessels in the brain. Fortunately, current microsurgical techniques take great care to preserve all major blood vessels encountered during the removal of the tumor, making a stroke quite rare. However any significant changes in thought processes or neurological functioning should be immediately reported to physicians.
Tinnitus is a common presenting symptom of acoustic neuroma. There is no cure and it can impact quality of life, but many patients learn to live with it. Tinnitus is the official name for that noise produced in the inner ear, such as ringing, buzzing, roaring, clicking, etc.