Otolaryngologists sometimes prescribe a tympanometry procedure. It shows the functional ability of the human ear. The result of the examination is a tympanogram, the decoding of which gives a more complete picture of the pathology of the middle ear in a patient.
The structure of the human ear
People's ears are complex and interesting.
External is represented by an auricle, the shape of which allows you to better capture sounds and protects the organ of hearing from environmental influences. As well as the ear canal, which rests against the eardrum, which transmits the sound wave further into the ear.
The middle is located behind the membrane and is represented by the tympanic cavity, where the auditory ossicles do their work, passing the baton of sound to the inner ear. The hammer, anvil and stirrup are fused into a chain, flying along which, the sound is amplified. The handle of the malleus is fused with the tympanic membrane, and the stirrup with its base enters the window of the inner ear. The latter, in the form of a labyrinth, is hidden in the human head. It serves not only to recognize sounds, but is alsovestibular organ responsible for balance and speed of movement.
Definition of tympanometry
Tympanometry is a technique for measuring the pressure that is created in the ear under the action of sound vibrations and is recorded graphically, which is shown by a tympanogram. With the help of such an examination, otolaryngologists want to understand whether the pressure in the tympanic cavity is normal and whether there is fluid there, whether the auditory ossicles are moving at full strength, whether the tympanic membrane is performing its function, whether it is intact.
Indications for examination
There are a lot of them:
- Otitis media. This is inflammation that occurs due to the fault of bacterial and viral microflora, hypothermia, and a decrease in the body's immune defenses. In this case, the patient is concerned about pain in the ear of varying intensity and hearing loss. Possible discharge from the ear canal. The inflammatory process in the ear, if not treated in a timely manner, goes into a chronic stage, and the disease can bother a person for years.
- Obvious or suspected damage to the eardrum, occurring both with direct trauma to the ear canal, and with an indirect blow to the head or with an inflammatory process that affected the membrane up to its perforation.
- Pathology or damage to the auditory tube, which is the link between the middle ear and the nasopharynx. Inflammation is accompanied by pain, congestion and hearing loss.
- Tumoursof various nature (glomus, tympanal paraganglioma, hemangioma, osteoma) and cysts formed in the middle ear, making hearing difficult, causing pain and discomfort.
- A rapidly increasing hearing loss for no apparent reason.
- Inflammatory changes in the behind the ear: redness and soreness of the skin, enlarged behind the ear and submandibular lymph nodes, fever.
- Impaired breathing through the nose, snoring, combined with hearing loss.
- The presence of wax plugs that impair hearing and cause an unpleasant sensation of changing and distorting your voice.
- Inflammation and degenerative processes affecting the auditory nerve.
- Frequent inflammatory processes in the nasopharynx in children, including adenoiditis.
To assess the effect of the treatment of chronic inflammatory processes of the middle ear, deciphering the tympanogram will also come in handy.
Contraindications for manipulation
Such a survey has a number of limitations. Here they are:
- Presence of profuse serous or purulent discharge from the ears.
- Pronounced redness and swelling of the eardrum, accompanied by shooting pain.
- Foreign bodies (headphone tips, caps, balls, buttons, fragments of cotton swabs, insects, etc.). Before the tympanometry procedure, they must be removed from the otolaryngologist.
- Volume sulfur plugs. They must also be removed in order to carry out the procedure safely and more effectively.
No manipulationon the introduction of a probe into the ear canal in case of serious violations of general well-being: presyncope, mental insanity or severe agitation, an increase in epileptic seizures in recent days.
Care should be taken in patients undergoing microsurgical operations of the middle ear and tympanic membrane. This should only be done if the interpretation of the tympanogram is important for the further management of the patient.
Adult technique
After explaining to the patient all the stages of the manipulation and obtaining his consent, it is necessary to perform an otoscopy, that is, examine the ear canal for the presence of foreign components, sulfur plugs and secretions. If everything is in order, then you can proceed to the examination. No additional preparation, except for personal hygiene, is required from the patient.
The he alth worker carrying out the procedure inserts a probe with a nozzle that matches the size of the ear canal into the patient's ear to seal it tightly. The probe is equipped with a pump that changes the pressure in the ear canal, a sound generator - it sends sound signals to the microphone, which is necessary to capture the reciprocal sound reflection. Signals with a frequency of 220 hertz and a noise intensity of 85 dB begin to enter the patient's ear. They make the eardrum vibrate, and the microphone picks up the vibration. The device produces a graph for each ear according to the type of tympanogram, the decoding of which by a specialist will help to putdiagnosis.
Method of carrying out in children
The child needs to be explained, but it is better to show on the mannequin all the moments of the examination. The most important thing that a small patient should understand is that this procedure, despite the introduction of a foreign object into the ear, is painless and passes quickly - about 10 minutes.
The baby should be told that during tympanometry you can not spin, talk, dangle your legs, swallow saliva, chew, cry and laugh. The child must sit motionless during the entire manipulation. Parents are advised to hold small children in their arms. This examination, with the right approach, is absolutely safe and is carried out even for infants.
Probe up to four months of age recommended with high frequency readings. Also, the size of the nozzles varies depending on the age of the child.
Deciphering a tympanogram in children (in normal and pathological processes) is carried out by specialists in functional diagnostics or by otolaryngologists themselves. Only by prescribing and evaluating all methods of examination, the doctor can prescribe the correct treatment.
Tympanogram interpretation
The result of the procedure is a graph, separate for each ear. It displays how the organ of hearing perceives sounds of different frequencies, what pressure is recorded in the ears at the moment, how the sound signal is reflected and absorbed. The method is objective, that is, independent of the subjective feelings of the patient. The result depends only on the state andfunctioning of the middle and outer ear of the examined person.
Tympanogram results are usually interpreted by a functional diagnostician who is trained to understand this type of examination. And then the otolaryngologist prescribes the necessary treatment or additional examination. In addition to tympanometry, audiometry should be done to clarify the presence of a particular disease.
Normal tympanogram
Normally, the decoding looks like an isosceles triangle, which is in the middle of the graph. This means that everything is in order with the pressure in the tympanic cavity and it is equal to atmospheric pressure. There is no fluid in the middle ear. The tympanic membrane and auditory ossicles function normally. The sound is transmitted almost completely inside the ear structures.
Types of tympanograms
According to various authors, the interpretation of tympanometry can be carried out according to the number of types of graphs from three to fifteen. Most often, seven types of transcripts are used.
Type A described above corresponds to a normal tympanogram.
Type B looks like a straight line on the chart. Consequently, the tympanic membrane practically does not respond to pressure fluctuations, which indicates either damage to it or the presence of fluid in the tympanic cavity. Such changes are observed in otitis media.
Type C shows the shift of the graphical curve to the left along the x-axis. This is interpreted as a violation of the patency of air through the Eustachian tube, which connects the middle ear with the nasopharynx. Such violationspossible with inflammation of the auditory tube itself or pathology from the mouth (tonsillitis, abscess), tumor formations.
Type D on the chart gives a side sharp spike that makes the pattern look like the letter "M". Such a curve is typical for scarring and atrophy of the tympanic membrane.
Type E appears on a tympanogram at high pulse rates as a curve with one or more rounded additional peaks. This occurs when there is a disturbance in the chain of the malleus, stapes and anvil associated with inflammatory, traumatic or degenerative processes.
Type Ad shows such a high peak that its top can go beyond the boundaries of the graphic image. This is due to the high lability of the tympanic membrane as a result of cicatricial deformities, violation of the tone of the membrane, rupture of the ossicles in the middle ear or their anomalies, which are present from birth.
Type As looks almost normal, but the amplitude is lower than type A. This is due to otosclerosis, a thickening of the eardrum due to scarring.
Pros and cons of research
Pros are:
- Objectivity - the final conclusion will depend purely on the operation of the elements of the hearing aid, and not on what the patient hears or does not hear.
- Efficiency - according to the schedule, a competent doctor can make a preliminary diagnosis and decide on the concept of treatment.
- Painless - the method does not cause discomfort and can be used even fornewborn babies.
- Fast - examination takes less than ten minutes.
The cons are that:
- The study is not always informative, since the type of curve can characterize several pathological processes.
- Presence of contraindications.
- Lack of staffing with tympanometry devices in all medical institutions.
