Through the Otoscope
Dr. Rensink is a member of ENT Associates of San Diego, and has been a practicing ENT specialist for more than 35 years.
The mysteries of the outer ear disappear as you pass through 10, 20, and 30 years of practice, but some pathologies you've seen hundreds of times but never knew what they were. Tympanosclerosis, for example, is one of the most common abnormalities, but I would guess that many have seen the white patches, unfamiliar discolorations, and thickening of the eardrums, and wondered what they were.
Recall from your anatomy class that eardrums have three layers: the outer ectoderm, the middle mesoderm, and the inner endoderm. Most cases of tympanosclerosis occur in the middle fibrous layer of the drum. Chronic ear disease is thought to stimulate an increase in the number of cells in the ear. These extra cells are the same types seen in scar tissue. Rigidity—the lack of movement when the ear is manipulated with a pneumatic otoscopic—comes from an excessive accumulation of these cells. The pathophysiology of tympanosclerosis and scar tissue are related but not identical. Some doctors will tell their patients that they see a lot of “scars” on their eardrums when what they really see is evidence of tympanosclerosis.
Healthy, normal eardrums are translucent so that you can often identify anatomical features in the middle ear space, such as the incudostapedial joint. Tympanosclerosis often eliminates the translucent nature of the eardrum, and you become more concerned by what you can't see than what you can. In many cases of tympanosclerosis, the tissues have a rough skin-like appearance, and all aspects of the translucent nature are lost. If this ear also has significant conductive hearing loss, a flat tympanogram, and rigidity, all indicators point to tympanosclerosis.
DEGREES OF DISEASE
In a mild case of tympanosclerosis, the hardening of the ear is not substantial, often only be a small, oval-shaped white patch in the upper right quadrant of the ear, and the patient likely will not be aware of it. (Figure 1.) In more severe cases of tympanosclerosis, a much larger, white, oval-shaped zone will appear in the ear. (Figure 2.)
When eardrum tissue hardens, the effect may be so slight that there is no change in the patient's hearing; the photographs seen here are examples of highly visible conditions that did not alter the patient's hearing. If tympanosclerosis is advanced, the effect on hearing may be significant, and may encompass middle ear structures as well. This problem is difficult medically and surgically. if the patient's ear has a long history of disease, hearing may no longer be the primary concern, and the overall welfare and health of the patient may be in question. The goal of medical intervention may be to stabilize a deteriorating condition.
It helps to remember that tympanosclerosis is closely related to ear disease. Hearing tests and otoscopic studies of the ear help demarcate the progression or cessation of this condition. It is important to perform these examinations annually, and if you are in doubt about the status of a particular patient's ear, always refer to a specialist.
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