15 W. Dry Creek Circle                                                                                           6169 S. Balsam Way; Suite 290
         Littleton, CO  80120-4427                                                                                                                                   Littleton, Colorado  80123
     Phone: (303)  798-1309                                                                                                                                        Fax: (303) 798-2319
Ear, Nose & Throat Center
Specialists of the Ear, Nose and Throat   /  Head and Neck Surgery  /  Facial Plastic Surgery
Evaluation  of  Dizziness  &  Vestibular Disorders

For more information see us at our web site !      http://www.ENT Center.Net
   
OTOSCLEROSIS

THE NORMAL EAR
To facilitate an understanding of the normal function of the ear, it can be divided into three portions:  The outer, middle and inner ear. The outer ear is made up of the auricle ( that part of the ear on the outside of the head ) and the external canal. The middle ear is separated from the outer ear by a thin membrane (the eardrum).  The middle ear is composed of the tympanic membrane, three little ear bones  (the malleus or hammer, the incus or anvil, and the stapes or stirrup, the mastoid air cells, and the eustachian tube).  The air space surrounding the little ear bones and extending back into the mastoid cells is known as the middle ear space.  This space is normally filled with air which comes up through the eustachian tube from the throat into the middle ear.  Behind the middle ear space is a bony honeycomb of air pockets called the mastoid. A third portion, the inner ear, is composed of two segments:  the cochlea (the hearing organ) and the labyrinth (the semicircular balance structures).  Both the cochlea and the labyrinth are normally filled with a fluid which bathes the delicate nerve endings of the hearing and balance nerve.

HOW WE HEAR:
Sound travels through movement of air molecules, creating sound waves, which pass through the external ear canal and strike the eardrum, causing it to vibrate.  These vibrations are then transmitted through the chain of little ear bones to the fluid of the inner ear.  A fluid wave is created and spreads through the cochlea, stimulating the delicate endings (hair cells) of the hearing nerve.  These nerve endings (hair cells) then generate a nerve impulse which travels along the hearing nerve to the center for hearing in the brain, where the impulse is interpreted and processed into meaningful sound.

                                  
TYPES OF HEARING IMPAIRMENT:
The external ear and the middle ear conduct sound; the inner ear receives and converts sound to nerve impulses.  If there is some difficulty in the external or middle ear, a conductive hearing loss occurs.  If the trouble lies in the inner ear, a sensorineural or nerve hearing loss is the result. When there is difficulty in both the middle ear and the inner ear, a combination of conduction and sensorineural impairment, or mixed impairment exists.

HEARING TEST
Hearing tests administered in the audiology department provide a very important part of the patient's examination.  These test results provide information as to whether or not a hearing loss exists.  If a hearing loss is found, the results of these tests indicate the degree of hearing loss present as well as the type of hearing loss the patient has.  Therefore these results influence the treatment and recommendations for the patient.

Several different types of tests are performed or supervised by a certified audiologist.  These may include such things as: (1) the amount of hearing loss present at each different pitch or frequency, (2) the amount of hearing loss present for speech in terms of loudness, (3) whether or not the hearing loss is conductive, mixed or sensorineural, and (4) the amount of hearing loss for the clearness or discrimination of speech, that is, how clear the words of speech are, once they become loud enough to hear easily.

Another type of test performed in the audiology department is known as tympanometry.  This is not a test of hearing ability,but rather a test to determine whether or not the eardrum and the three small bones in the middle ear are functioning properly, a swell as to see if the ear pressure behind the eardrum is normal. Results of this test are recorded on a tympanogram; results of the hearing tests are recorded on an audiogram.

The ear physician may do a screening evaluation on the patient's hearing with instruments called tuning forks.  The exact hearing level cannot be determined with tuning forks, as they tend to indicate the type of hearing loss but do not indicate the degree.

OTOSCLEROSIS:
The word "otosclerosis" means ear bone hardening.  The bone affected is the stapes bone, the smallest bone in the human body. It becomes fixed from the hardening process, interfering with its normal vibration.  This fixation of the stapes bone causes conductive hearing loss. Otosclerosis is a hereditary disease, and many patients with this disease often know of other members of their family who have had similar hearing problems.  On the other hand, the otosclerotic patient may not be aware of the presence of hearing loss in the family, as this disease is not manifested in all generations.  The fact that a patient has otosclerosis does not necessarily mean that his or her children will also be affected.

Hearing loss from otosclerosis is rare in children, and when it is noted, it is usually late in the teen years.  More often, it is first noted after the age of 20 and almost always before the age of 45. Many years are usually required before the hardening process caused by otosclerosis significantly interferes with the transmission of sound vibrations from the stapes bone to the hearing nerve, causing noticeable hearing loss.  Very rarely does otosclerosis cause total deafness.  At any time, the activity of the hardening process may cease, in which case the hearing loss grows no worse. Otosclerosis appears about twice as frequently in woman as in men.

The otosclerotic hardening process develops very slowly, fixating the stapes bone so that it cannot vibrate properly.  In otosclerosis, most of the hearing impairment is due to this bone fixation.  However, part of the hearing loss may be due to otosclerosis causing damage to the hearing nerve.

That portion of the loss due to nerve damage cannot be corrected. Head noises, called tinnitus, such as ringing, roaring or hissing often develop in patients with otosclerosis.  This head noise is usually more noticeable when the patient is tired or tense, or in a quiet environment.

TREATMENT OF OTOSCLEROSIS

MEDICAL:
Currently, there is no drug that will improve the hearing in persons with otosclerosis.  In some patients, the drug sodium fluoride is prescribed in cases showing evidence that the inner ear has been damaged or is likely to be damaged.  This drug is administered in tablet form; usually, calcium and multivitamin tablets are also prescribed along with sodium fluoride.  Women who are pregnant or who are contemplating pregnancy should not take sodium fluoride; also, persons with severe kidney disease should not take this drug.  Sodium fluoride occasionally causes side effects, including gastric distress, aggravation of arthritis, and skin rashes; all of these problems clear up on discontinuation of use of the drug.

SURGICAL TREATMENT:
In most cases, surgical treatment of otosclerosis is successful in restoring hearing.  The operation, called stapedectomy, involves removing part or all of the stapes bone.  The entire operation is done under magnified vision, using an operating microscope.  Since the incision is made deep in the ear canal, there is no visible incision line or scar, except for a tiny incision which may be made above the ear or in front of the ear to obtain a piece of connective tissue to serve as a graft in the ear.   The small skin flap and attached eardrum are carefully lifted and folded forward so that the stapes bone can be seen.  Part or all of the fixed stapes bone is delicately removed by one of several available techniques.  With either partial or total stapes removal, the inner ear is exposed; the inner ear opening must be sealed off to protect tiny delicate nerve endings.  For this purpose, the tissue graft or some of the patient's own clotted blood may be used.

A tiny prosthesis, made of stainless steel or plastic, is inserted to replace the removed stapes bone.  This prosthesis allows sound to be transmitted normally once again from the eardrum to the inner ear.  After the prosthesis has been inserted, the eardrum is replaced in its normal position, the ear canal is lightly packed, cotton is placed at the opening of the ear, and the operation is completed.  A head dressing is placed over the ear for approximately 24 hours.

Stapedectomy procedures may be done on an outpatient basis.  When stapedectomy is done on an outpatient basis, patients living outside the Denver metropolitan  area usually plan to remain in the Denver metropolitan area overnight following the operation.  Bed rest with bathroom privileges is advised the first 24 hours following surgery.  On the first day after surgery, the patient is allowed to be up as desired and able.  On the second postoperative day, the patient can move about freely.  Most patients are able to return to work in one to two weeks, depending upon the occupation.

Any remaining bone growth (otosclerosis) tends not to attach to the prosthesis; hearing improvement is usually permanent. Although some hearing improvement may be noted at the time of surgery, this usually disappears in a few hours following the operation due to bleeding in the ear as well as packing in the ear canal.  Three to four weeks is often required before hearing improvement is noted.  Over the next three to four months there is an additional increase in hearing level and quality of sound.

No surgical procedure is completely free of some risk.  More than 90% of our patients undergoing stapedectomy do obtain satisfactory results.  A small number of patients, less than 3%  have worse hearing after surgery in the operated ear.  Another small percentage of patients have unimproved hearing.  Patients whose hearing is not changed after surgery may obtain hearing improvement with a second operative procedure.

Many patients complain of some dizziness following surgery.  Some individuals do not become dizzy, but many are mildly unsteady for the first postoperative week.  Occasionally, patients may be affected by dizziness for as long as several weeks to several months.  The dizziness may be more pronounced on sudden head motion for several weeks; in this situation, sudden movements of the head should be avoided.  In a few patients, nausea and vomiting may accompany the dizziness experienced in the immediate postoperative period.

One of the nerves of taste is located in the middle ear, and sometimes following ear surgery, the patient will notice changes in taste, usually described as a brassy taste.  This taste disturbance subsides in most patients within two or three weeks. In rare cases it may be long standing or permanent.

The facial nerve, which controls the muscles of expression in the face, also passes through the middle ear.  Facial weakness or paralysis is rare following stapes surgery, but it can occur. Fortunately, the nerve irritation is usually temporary and clears up spontaneously.

Most normal activities may be resumed within two weeks following surgery.  All patients are cautioned against future exposure to loud noises.  A loud noise may damage an otherwise satisfactory hearing result, as the operated ear may be more susceptible to loud noise. Air travel is allowed within two weeks following surgery.