HIS 125 The Acoustic Tumor

THE ACOUSTIC TUMOR

You encounter a person with unilateral hearing loss. They wish to get a hearing instrument for the ear because it has always been their favorite ear to use on the phone.

You choose to not dispense a hearing instrument to them and make a referral to a physician for further investigation of the condition.

THE ACOUSTIC TUMOR

The person chooses to obtain a hearing instrument over the internet because all they want to do is hear better on the phone.

No professional is willing to dispense a hearing instrument without recommending a medical referral.

THE ACOUSTIC TUMOR

The person notices the left portion of their face is beginning to “tingle” and feel numb,

They believe the numbness is probably from the headaches resulting from long hours at work—their poor vision from long hours on the computer.

THE ACOUSTIC TUMOR

Over the winter, the person slips on the icy sidewalk, falls, and breaks a hip and becomes bedfast for several weeks following the surgery.

The physical therapy is not responding well as an ataxic gait has developed.

THE ACOUSTIC TUMOR

The person discontinues use of the hearing instrument because they really only needed it for the phone at work and are now unable to work.

The post surgery medications and over the counter meds all seem to create nausea and occasional vomiting.

THE ACOUSTIC TUMOR

The person believes the fall has disabled them from much physical activity; and choose to spend most of their time at home or in bed.

A few years later, they are pronounced dead due to respiratory failure.

THE ACOUSTIC TUMOR

Further investigation of the cause of death reveals a large acoustic neuroma in cerebella pontine area—behind the temporal bone.

Hearing loss is a symptom---not a disease!

THE ACOUSTIC TUMOR

Acoustic neuromas account for about eight percent of all primary intracranial tumors and about ninety percent of all tumors located in the cerebellopontine angle.

THE ACOUSTIC TUMOR

Tumor Characteristics

A tumor is commonly referred to as a neoplastic growth.

It is an abnormal persistent tissue mass which may be either in a benign or malignant form.

Malignant tumors grow more rapidly and benign tumors grow more slowly.

THE ACOUSTIC TUMOR

Tumor Characteristics In general, most acoustic neuromas are benign, slow-growing neoplasms.

They usually take the path of least resistance and grow from the internal auditory canal area of the temporal bone back into the cerebellopontine angle.

It will eventually compress the brainstem and cerebellum.

THE ACOUSTIC TUMOR

Tumor Characteristics

About seventy-five percent of the tumors grow less than 0.2 cm/year.

Of course, the other twenty-five percent grow at a greater rate.

THE ACOUSTIC TUMOR

Tumor Characteristics

There are commonly three stages of growth which will manifest various physical conditions. They are:

1. The internal auditory canal stage

2. The early cerebellopontine angle stage

3. The late cerebellopontine angle stage

THE ACOUSTIC TUMOR

The most common physical symptom is a complaint of unilateral hearing loss and tinnitus.

A reported observation of poor understanding over the telephone with use of the affected ear is also often reported.

THE ACOUSTIC TUMOR

Other symptoms observed/reported may be a slow corneal reflex, facial numbness, and asymmetrical eye blink (one eye will blink more slowly than the other).

THE ACOUSTIC TUMOR

Tumor Assessment/Diagnosis

Any asymmetrical sensorineural hearing loss with unusually poor word recognition (as revealed through audiometry) should be considered suspicious and referred for further medical analysis.

THE ACOUSTIC TUMOR

Tumor Assessment/Diagnosis

No single auditory test is precise enough to be a perfect site-of-lesion indicator.

Tumor size will even effect the validity of auditory brainstem tests.

However, if abnormal ABR results are revealed, there is over a ninety percent chance that there is a retro-cochlear lesion present.

THE ACOUSTIC TUMOR

Tumor Assessment/Diagnosis

There are other tests available to assist with determining acoustic neuroma presence and site-of-lesion. They are:

Vestibular testing—specifically calorics

Radiologic imaging—specifically MRI w/contrast (can “see” tumors as small as 2mm)

THE ACOUSTIC TUMOR

Acoustic Neuroma Management

As with any medical challenge, early detection of lesion will result in its most effective management. Four management protocols are normally implemented. They are: 1. Hearing preservation surgery

2. Destructive surgery

3. Stereotactic radiotherapy (gamma knife)

4. “Waitful observation”

THE ACOUSTIC TUMOR

Hearing Preservation Surgery

When the acoustic neuroma is small (detected early), current surgical procedures can remove the tumor without destroying the remaining hearing within that ear.

THE ACOUSTIC TUMOR

Destructive Surgery

A large of “fast-growing” acoustic neuroma may require this procedure. It will destroy any remaining hearing within the ear but, further life-threatening complications will be ameliorated.

These tumors are often larger than two centimeters.

THE ACOUSTIC TUMOR

Stereotactic Radiotherapy

The “gamma knife” is used when the surgeon believes there may be too many bleeding or neural issues present thus contraindicating an invasive surgical procedure.

THE ACOUSTIC TUMOR

“Waitful Observation”

Given that seventy-five percent of acoustic neuromas are benign (slow-growth), this is a common recommendation for elderly patients with an acoustic neuroma.

Note: The death rate from surgical complications has been reduced from 3.7 percent in 1960, to about 0.5 percent today.

THE ACOUSTIC TUMOR

Case Reports

Let’s review the three case reports found on pages #220--#224.

THE ACOUSTIC TUMOR

Every patient/client with unexplained asymmetrical, unilateral sensorineural hearing loss, facial nerve problem, or dizziness episodes should be considered to have an acoustic tumor until proven otherwise!