Conductive relative deafness – a hearing disorder which is characterized by the complicated carrying out sound waves to the sound perceiving device. The main clinical signs – decrease in auditory acuity, "congestion" of ears, the strengthened perception of own voice, deterioration in differentiation of the speech from surrounding noise. Diagnostics includes the analysis of anamnestichesky data, the complaints given to an otoskopiya, an audiometriya, Rinne's tests, Weber, the tympanometry. Therapeutic tactics depends on an etiopatogenetichesky form of a disease and can include both medicamentous, and expeditious treatment.
Conductive relative deafness
Conductive relative deafness – widespread pathology in otolaryngology that is connected with existence of a large number of etiologichesky factors. In the general structure of a disease about 67% of cases result from damages of an Eustachian tube, the acoustical channel or a drum cavity. In 2,1% of observations pathology is followed by irreversible changes in the sound carrying out system. The disease meets in the senior age group more often. According to statistical data, children are ill 13 times less often than adults. At representatives men's and female this pathological state meets identical frequency.
Reasons of conductive relative deafness
The main reasons for this form of loss of hearing – violation of conductivity of a sound signal from an external ear to the sound perceiving device. It results from distortion of sound waves at their passing through an external and middle ear, endolymphatic space and membranes of a snail that can be caused by the following etiologichesky factors:
- Violation of passability of an external ear. Sulfuric traffic jams, foreign matters, tumors, external otitis, "the swimmer's ear", ekzostoza, traumatic damages and a congenital atresia of an acoustical campaign worsen or make impossible passing of sound vibrations to an eardrum.
- Injury of an eardrum. Here belong: perforation against the background of a sharp acoustic trauma, , sharp differences of atmospheric pressure (at bystry ascent or descent). Violation of integrity of a drum partition complicates transfer of mechanical oscillations on acoustical stones.
- Damage of a middle ear. Ekssudativny and purulent average otitis, , tubootit, the holesteatoma, obstruction of a pharyngeal opening of an Eustachian tube adenoidny vegetations or other pathological structures are followed by violation of mobility and the carrying-out function of acoustical stones.
- Diseases of an inner ear. Impassability of a round or oval window of a snail and a digistsention of the forward polukruzhny channel are capable to obstruct the normal traffic of the endolymph transferring vibrations to kortiyevy body.
Dysfunction of the sound carrying out system – external acoustical pass, an eardrum, a cavity of a middle ear and acoustical stones, an endolymph or membranes of a snail is the cornerstone of pathogenesis of conductive relative deafness. Normal all these structures are responsible for strengthening and sound transmission to structures of system of sound perception. Violation at least of one of links of this chain leads to distortion of fluctuations and the general deterioration in hearing. Function of kortiyevy body, the acoustical nerve and back departments of the top temporal crinkle which are responsible for perception and processing of heard is not broken. At the expense of it at patients normal bone conductivity of sounds remains. In hard cases its sensitivity exceeds air because of what the person fully perceives only own speech.
Depending on expressiveness of deterioration in hearing mark out 4 severity of conductive relative deafness:
- I degree. The person is capable to perceive the shepotny speech at a distance to 3 meters, colloquial – to 15 m. The distorted speech or a conversation in the conditions of external noise are not perceived at all. The voice-frequency threshold is in limits of 20-40 decibels.
- II St. The patient can investigate whisper at distance to 1 meter, an ordinary conversation – to 5 m. Sharply legibility of the speech in normal conditions worsens. Sounds with a volume not lower than 40-60 dB are normally perceived.
- III St. It is characterized by an opportunity to perceive informal conversation from a distance no more than 2 meters. Whisper and sounds lower than 50-70 dB do not differ.
- IV St. The patient loses ability to recognize the human speech without auxiliary acoustical devices. The voice-frequency threshold makes 70 dB and more.
Symptoms of conductive relative deafness
The main symptom – gradual or sharp loss of auditory acuity. It is shown by deterioration in perception of the informal and shepotny conversation, impossibility to differentiate words of the interlocutor from external noise. One of characteristic clinical manifestations – feeling of "congestion" of ears. Patients describe this state as "the ears which are stopped up with fingers or earplugs". At the same time own voice of people perceives louder than surrounding sounds. Various etiologichesky forms of deterioration in hearing can lead as to unilateral, and bilateral defeat. At development of relative deafness against the background of inflammatory diseases (external and average otitis, tubootit etc.) decrease in hearing is followed by temperature increase of a body, ear pain which amplifies when sneezing or chewing. As a rule, after full treatment hearing is in whole or in part restored.
Development of complications of conductive relative deafness is defined by an etiology and duration of a course of a disease. In most cases they are connected with transition of inflammatory diseases to chronic forms which lead to repeated defeats of the sound carrying out system. In certain cases pathological processes extend to regional anatomical structures. Damage of a temporal and mandibular joint leads to its dysfunction that is shown by strengthening of an ear-ache during the chewing and a conversation. When involving in process of an inner ear, an acoustical nerve or brain covers function of the sound perceiving device is broken, neurotouch relative deafness and permanent loss of hearing develops.
Diagnostics at a conductive form of deterioration in hearing consists in definition of a cause of illness, an objective and tool research of the sound carrying out system of an ear. An important role is played by the correct collecting the anamnesis: specification of earlier postponed diseases, injuries etc. For diagnosis it is carried out:
- Otoskopiya. At objective survey of an external ear inflammatory or structural changes of acoustical pass, existence of a sulfuric stopper or foreign matter are defined. Also this method allows to study structure of an eardrum and to reveal its protrusions, retraktsionny pockets, hyperaemia or perforation.
- Kamertonalny tests (Rinne, Weber). At conductive relative deafness sounding of a tuning fork is perceived louder at its arrangement on a mastoidal shoot, than near an auricle. During Weber's test the sounding tuning fork is established on a parietal part of the head on the median line. At a unilateral conductive hearing disorder sounds of a tuning fork stronger are perceived from the struck party.
- Audiometriya. Allows to reveal progressive decrease in curve air conductivity on condition of preservation of normal function of the sound perceiving device.
- Tympanometry. Displays increase of an acoustic impedance on average to fish soup. More intensive reflection of a sound testifies to it. The test is most informative at damage of a middle ear with allocation of a large number of a transsudat.
- Beam methods of diagnostics. The X-ray analysis of temporal bones, KT and MPT of this area are applied at low informational content of all above-mentioned methods of a research. These techniques allow to reveal anomalies of a structure of acoustical pass, a middle and inner ear, to precisely establish the reason and a form of relative deafness.
Differential diagnostics is carried out with a sensonevralny form of relative deafness. As the main diagnostic criteria serve results of an audiometriya, Rinne and Weber's tests. Unlike conductive relative deafness on an audiogramma deterioration in both bone, and air conductivity will be observed. In Rinne's test the sound better is perceived at the provision of a tuning fork opposite to an auricle. When conducting test of Weber sounding of a tuning fork are listened better from a healthy ear.
Treatment of conductive relative deafness
Medical actions at this disease are directed to elimination of the leading etiologichesky factor breaking sound carrying out. Thus, medical tactics comes down to application of pharmacological means or carrying out surgical intervention. Main methods of treatment:
- Pharmacotherapy. Intensive antibiotic treatment is shown at early stages of deterioration in the hearing which resulted from inflammatory diseases – external or average otitis, an evstakhiit. As a rule, antibiotics of a broad spectrum of activity are used. At defeat of acoustical pass washing of an ear by solutions of anti-septic tanks, purpose of NPVS or glucocorticoids is shown.
- Expeditious treatment. Surgical tactics can mean extraction of a foreign matter from an ear, restoration of functions of an eardrum (a miringoplastik, a timpanoplastik), drainage of a drum cavity, prosthetics of acoustical stones (ossikuloplastik), removal of purulent masses from a mastoidal shoot (mastoidotomiya), etc.
- Hearing aid. Use of hearing aids is shown at development of the changes in an external or middle ear which are not giving in to treatment. Artificial strengthening of the perceiving sounds compensates function of the sound carrying out system at the expense of what to the person ability to hear comes back.
Forecast and prevention
The forecast at a conductive hearing disorder depends on reversibility of changes in the sound carrying out system. Most of patients has result of treatment a complete recovery of hearing to initial level. In the heavy or started cases hearing can come back only partially. Specific preventive measures concerning this disease it is not developed. Early diagnostics and treatment of diseases of an external ear, drum cavity, nasopharynx, routine inspections of the otolaryngologist, observance of rules of personal hygiene, prevention of injuries of temporal area belong to nonspecific prevention.