Acoustic Neuroma Nursing Management and Interventions

Think of it as a slow-growing benign tumor that picks off one ear and then balance. Unilateral hearing loss with tinnitus is the classic opener, and your job is fall prevention and supporting a patient whose hearing and equilibrium are eroding.

Definition

An acoustic neuroma is a benign tumor on the eighth cranial nerve (vestibulocochlear), which runs from the brainstem to the ear and carries hearing and equilibrium. These tumors grow slowly.

Acoustic neuromas occur sporadically or as part of von Recklinghausen neurofibromatosis, where the neuroma takes one of two forms. In neurofibromatosis type I, a schwannoma may sporadically involve the 8th nerve, usually in adult life, but can involve any cranial nerve or the spinal root; bilateral acoustic neuromas are rare in this type. In neurofibromatosis type II, bilateral acoustic neuromas are the hallmark and typically present before age 21, tend to involve the entire nerve, and show strong autosomal dominant inheritance. Incidence is about 5 to 10%.

Causes

The exact cause is unknown.

Risk Factors

Age 30 to 60 (average age of diagnosis is 50). History of neurofibromatosis type 2 (for bilateral neuromas only, which are very rare).

Symptoms

First signs: gradual hearing loss in one ear, decreased sound discrimination (especially on the telephone), and ringing in the ears (tinnitus).

As the neuroma enlarges: balance problems, facial numbness and tingling, and weakness of the facial muscles.

Diagnosis

Audiogram. Measures hearing in both ears.

Auditory Brainstem Response Test (ABR, BAER, or BSER). Measures the rate of electric impulses traveling from the inner ear to the brainstem. A slowed or absent impulse suggests an acoustic neuroma, and this test is almost always abnormal when one is present.

Electronystagmography. A balance test. Cold and warm water or air is introduced into the ear canal, and the resulting dizziness and rapid eye movement (nystagmus) is recorded.

MRI scan. Uses magnetic waves to image the inside of the body.

CT scan. An x-ray that uses a computer to image the inside of the body.

Nursing Diagnoses

Risk for Falls related to loss of balance. Disturbed Sensory Perception (auditory). Risk for Imbalanced Nutrition: Less Than Body Requirements related to weak facial muscles.

Treatment

Observation. If the tumor is very small, the physician may just monitor growth. This is common in people over age 70.

Microsurgical removal. As the tumor grows or hearing worsens, removal may be necessary. The surgical approach depends on tumor size and location. Complications can include permanent hearing loss and paralysis of the facial muscles on the affected side.

Radiation therapy (radiotherapy). Radiation kills cells and shrinks the tumor, and is expected to halt further growth. It may be used when tumors are small and surgery is not possible, and may preserve hearing.