The signs and symptoms of acoustic neuroma develop from a tumor pressing on VIII cranial nerves.

Signs and symptoms

• Gradual hearing loss, although sudden in some cases and occurring on only one side or more pronounced on one side. Its sensorineural hearing loss.
• Ringing sensation (tinnitus) in the affected ear
• Pressure in the ear
• Dizziness (vertigo)
• Nausea and vomiting
• Loss of balance or equilibrium
• Altered gait

The tumor also may press on the brainstem structures (pons, midbrain, and medulla). If facial nerve (VII cranial nerve) is involved

• Ipsilateral facial weakness and numbness
• Impairment of sensations
• Impairment of glandular secretions
• Loss of taste sensation in the anterior two-thirds of the tongue

If trigeminal nerve (V cranial nerve) is involved

• Loss of sensation in the involved side's face and mouth

If glossopharyngeal (IX cranial nerve) and vagus nerves (X cranial nerve) involved

• Involvement may lead to altered gag or swallowing reflexes.

In rare cases, an acoustic neuroma may grow large enough to compress the brainstem and be life-threatening. Its associated symptoms such as headache, vomiting, and altered consciousness

Causes

• Most of the acoustic neuromas develop on a vestibular branch of 8 th cranial nerve
• The cause of acoustic neuromas is unknown or idiopathic
• Tumors, in rare cases, are an indication of neurofibromatosis 2, a genetic disorder that involves the growth of tumors on the vestibulocochlear nerve.
• Tumors associated with neurofibromatosis often affect the nerve on both sides (bilateral).

Complications

• Permanent hearing loss
• Facial numbness and weakness
• Difficulty in balance and clumsy gait

Tests and diagnosis

• MRI with gadolinium enhancement is the test of choice
• MRI or CT brain to confirm the diagnosis
• Hearing test- Audiometry
• Electonystagmography (ENG)
• Brain stem auditory evoked response (BAER)

Treatment

Monitoring

• In small acoustic neuroma that’s not growing or is growing slowly and causes few or no signs or symptoms, frequent monitoring is required, especially in an older adult
• Regular imaging with CT or MRI and hearing tests are required to determine whether the tumor is growing and how quickly.
• If the scans show the tumor is growing or if the tumor causes progressive hearing loss or other difficulties, there is a need to undergo treatment.

Stereotactic radiosurgery

• By using gamma knife, radiation is precisely given to a tumor without making an incision.

Surgical removal

• The goal of surgery is to remove the tumor and preserve the facial nerve to prevent facial paralysis and preserve hearing.
• Performed under general anesthesia, this type of surgery involves removing the tumor through an incision in your skull.