What is an Acoustic Neuroma?
Also known as a vestibular schwannoma, an acoustic neruoma is a benign tumor found in the nerves that lead from the brain to the inner ear and control balance and hearing. This common brain tumor is usually slow-growing and does not affect brain tissue like cancerous tumors do. Many patients do not experience any problems from this type of tumor since it can remain very small.
The cause of an acoustic neuroma is uncertain, although it may be associated with a rare condition called neurofibromatosis type 2, a genetic disorder that affects the same nerves. Other acoustic neuromas may be related to consistent exposure to loud noise, exposure to head and neck radiation or a medical history of a parathyroid adenoma. Most patients who develop this type of tumor are between the ages of 30 and 60 years old.
Patients with an acoustic neuroma may experience hearing loss as a result of the tumor placing pressure on the nerve, dizziness, ringing in the ears, loss of balance and facial numbness and weakness. If left untreated, an acoustic neuroma can lead to permanent hearing loss and a buildup of fluid within the head.
Acoustic Neuroma Treatment and Surgery
Treatment for an acoustic neuroma depends on the size and growth rate of the tumor, and may include observation, radiation or surgical removal. Small tumors can be monitored regularly through regular imaging and hearing tests to determine how fast and how much it is growing. Radiosurgery delivers radiation therapy to the tumor to stop it from growing without the need for an incision and is most often used for tumors that cannot be removed without damaging brain tissue. Larger or more aggressive tumors may be removed through surgery to prevent permanent damage from occurring.
When surgery is required, a suboccipital craniectomy is often the best method of treatment. This procedure involves removing a portion of skull bone to access and remove the acoustic neuroma. The term suboccipital refers to the location of the craniectomy, which is performed at the base of the skull. This allows Dr. Lipani to directly reach the cranial nerves near the back of the brain where the acoustic neuroma has formed.
The Suboccipital Craniectomy Procedure
A suboccipital craniectomy is performed with the patient under general anesthesia. The hair is shaved in the area and Dr. Lipani makes an incision in the skin of the scalp behind the ear. A specialized drill is used to create a hole in the skull bone and a portion of bone is removed. Through this opening, Dr. Lipani can access the auditory canal and nerves and carefully cut the acoustic neuroma out.
As the tumor is removed, stimulation is provided to the nerves involving hearing and facial movement as well as the brainstem to make sure no damage is occurring. In some cases, it is safer to leave a small portion of the tumor behind than remove it in its entirety and risk permanent loss of some function.
After the tumor removal, the skull bone is not replaced. However, if the hole is large enough, the area will be covered with a synthetic substance shaped to fill the missing bone. The incision in the skin is then sutured closed.
Recovery from Suboccipital Craniectomy
Most patients will remain in the hospital for three to five nights after undergoing a suboccipital craniectomy. The complete recovery process generally takes between four and 12 weeks. Common issues experienced by patients during this period of healing include headaches and fatigue.
Risks of Suboccipital Craniectomy
All forms of surgery pose some risks to the patient. The complications associated with suboccipital craniectomy for acoustic neuroma include hearing loss, facial weakness, balance difficulties, headaches, bleeding, infection, swelling of brain tissue, cerebrospinal fluid leakage and stroke.
Since acoustic neuromas can be recurrent, it is important to schedule follow-up appointments with your doctor. Imaging scans will be performed to ensure there is no sign of a tumor again.