Acoustic Neuroma - Symptoms, Diagnosis & Treatment

Acoustic Neuroma, which is also known as Vestibular Schwannoma, is technically a tumour. This tumour grows on the vestibular nerve (the main nerve) which connects the inner ear to the brain. This nerve influences one’s balance and hearing. The tumour on this nerve develops and grows slowly, making it hard to be perceived due to delayed symptoms. 

 

Acoustic Neuroma develops through cells that surround the vestibular nerve, known as Schwann cells. The pressure exerted by the tumour on the nerves or the branches of the verve may cause hearing loss, dizziness, or unsteadiness. If the tumour increases in size, it may press the veins disrupting the blood flow, which can be lethal. 

 

There are two types of Acoustic Neuroma:

 

Unilateral acoustic neuromas: This acoustic neuroma deteriorates only one ear and may happen due to environmental causes. 

 

Bilateral acoustic neuromas: Bilateral acoustic neuroma affects both the ears and usually originates due to neurofibromatosis-2 (NF2), which is a genetic disease. 

 

Symptoms

 

Acoustic neuroma is less likely to be evident in its early stages. Generally, the tumour grows slowly and so do acoustic neuroma symptoms. The signs of neuroma start to evolve once the tumour begins affecting adjacent nerves. The very first symptom is steady hearing loss in one ear. This can often be associated with dizziness and a ringing sensation in the ear. But most people consider it to be the effects of ageing. That is the reason, most patients are diagnosed with acoustic neuroma long after it actually starts to develop in their bodies. 

 

Major acoustic neuroma symptoms are listed below.

 

• Hearing loss in one ear 
• Feeling of heaviness in the ear 
• Ringing or buzzing sound in the ear (tinnitus)
• Dizziness (Vertigo)
• Unsteadiness, inability to balance properly
• Numbness in facial muscles
• Clumsy gait
• Headaches
• Mental Confusion
• Change in taste and voice
• Difficulty in swallowing

In severe cases, the tumour may cause permanent facial paralysis. Rarely, when the tumour grows very rapidly and becomes very large in size, it may be life-threatening by pressing the veins inside the brain.

 

Diagnosis 

 

In most cases, the acoustic neuroma isn’t diagnosed in its early stage. This happens because the symptoms of acoustic neuroma are often delayed and usually resemble other ear problems. For acoustic neuroma diagnosis, the ENT specialist will ask you some basic questions related to all the symptoms that you are experiencing. 

 

After analyzing your symptoms, the doctor may refer to one of the below tests for diagnosis:

 

• Hearing Test (Audiometry)

This is the basic test done to check how well a patient can hear. The analysis is carried out by an audiologist. Different sounds at different ranges are directed to each ear of the patient to identify the level of the problem. 

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• Videonystagmography

 

This technology is used for vestibular assessment, a test that is executed to check the functionality of the inner ear and central motor. Infrared goggles are used to detect eye movements during various visuals and positioning. This technology is used to identify the root cause of dizziness. 

 

• MRI (Magnetic Resource Imaging)

 

After acoustic neuroma diagnosis, magnetic resource imaging is used to confirm the tumour. This imaging technology involves the use of magnetic fields, radio waves, and computers to create a 3-D image of the brain’s interior. The MRI scan provides the image of the tumour in bright contrast dye. It also helps to identify the tumour’s size. 

 

Treatment

 

The method of acoustic neuroma treatment depends upon the size of the tumour. Surgeries can easily remove large tumours. But it is nearly impossible to remove small tumours through surgery. Many other factors also play important roles in deciding whether it will be treated by surgery or not. Two types of treatments are done to remove the tumour. 

 

1. Surgery: A small incision is made behind the ear to get to the tumour and then it is removed. There are three types of surgery. Translabyrinthine surgery is implemented to remove a tumour larger than 3 cms. But this type of surgery may result in some complications, including permanent loss of hearing. The other two- rectosigmoid and middle fossa are performed upon any size and small tumours, respectively. Retrosigmoid is a better alternative for Translabyrinthine because it enables the surgeon to protect the hearing of the patient while removing the tumour. Similarly, the middle fossa also allows the hearing to be preserved.

 

1. Radiation Therapy: This therapy helps remove the tumour without making cuts around the ear. Beams are directed at the tumour to remove it. This method uses one of the two techniques: single-fraction stereotactic radiosurgery and multi-session fractionated stereotactic radiotherapy. In the single fraction method, the tumour is removed in one session by aiming multiple beams at the tumour. Whereas, in the multi-session method, the tumour is exposed a little every day to radiations and is removed gradually. 

 

Acoustic neuroma treatment also includes observation before the surgery. The tumour is monitored to notice its growth and frequency of the growth. After the observation, the doctor concludes the surgery. After a successful operation, a patient is also suggested to go for supportive therapy to improve unsteadiness and unbalanced gait.