Hearing is one of the essential supports of communication and no complaints about the hearing should not be overlooked. There is no necessary correlation between the intensity of the patient’s complaint and the importance of hearing loss: if the deficit has progressively, the patient was able to get used to it gradually and do not complain on the contrary, if the deficit was brutal, the complaint can be major (Box 1). The level of requirements of the patient vis-à-vis the sound information is another factor that also modulates the complaint.
Instead we place the hearing in the collection of information is not the same for about 40 years in professional activity or for the retired 70-year person.
Their lifestyle and their exchanges with the outside are not comparable effect.
Hearing complaint can be expressed in different ways. It can affect the sound level: “I hear so well,” but it can also relate the understanding of speech.
This complaint is typically seen with age: “I understand that, but I do not understand what is said.”
Box 1. Key deafness
sudden deafness
Appearance within 24 hours of reaching the auditory sensory organ, with or without vertigo is a therapeutic emergency
chronic deafness
Transmission: tubal catarrh, glue ear, chronic otitis, otosclerosis, external or middle ear malformations
Perception: acoustic trauma, presbycusis, acoustic neuroma, pressionnelles diseases, toxic deafness, hearing loss autoimmune, genetic deafness
DIAGNOSTIC:
Examination:
The examination allows:
– Specify the speed of onset of deafness (see Box 1);
– Seek triggering circumstances: trauma, physical or sound, making potentially ototoxic drugs;
– The presence of signs associated with hearing loss: clogged ear sensation, ear pain, ear discharge (known as otorrhea if it is pus, to otorragie the case of blood), sensations dizziness or imbalance, tinnitus;
– Specify the permanence or otherwise fluctuating hearing loss;
– Clarify the patient’s personal medical history, otorhinolaryngological or other, and the notion of a possible family deafness;
– Specify the sound environment in which the patient is changing: one person, quiet or, conversely, working in a noisy environment, possibly through hunting, listening to music at high intensity, etc.
Clinical examination of the ear or otoscopy:
The only part of the auditory system clinically available is the outer ear consists of the pavilion and the external auditory canal and part of the middle ear, the eardrum essentially and through him the reliefs of the hammer and the anvil. Otoscopy is performed using an otoscope or mirror Clar. You have to pull up and back in pavilion to put the ear canal in a straight position, it is then to see the eardrum which typically appears light gray color, with a triangle a little brighter down and forward.
Particularly rhino-laryngo-pharyngeal, review research associated pathology. Infectious diseases of the middle ear may very well be the result, for example, a deviated septum or chronic sinus disease.
This research a possible involvement of other cranial nerves.
Hearing assessment:
Review essential before any hearing complaint, it clarifies the auditory level and the type of deficit.
Impedance:
The impedance consists of two parts: the realization of the tympanogram which provides information on the mechanics of the ear including the vibrational quality of the ossicular chain tympano- and research of acoustic reflex, reflex muscle contraction in response to the caliper a loud sound.
Realization of the tympanogram:
This examination is simple to implement, atraumatic for the patient and cost in time, completely objective as not requiring the subject’s participation. It is to seal in the ear canal and to send a sound that will be reflected on the tympanic membrane and collecting the reflected sound.
One can easily imagine that if the tympanic membrane is very tense it will further reflect the incident sound like a drum membrane. However, if the eardrum has lost its rigidity characteristics, the incident will be much less reflective. this sound reflection is studied by varying the pressure in the external auditory canal. then traces the tympanogram. This is normal in the case of a figure pagoda centered between -50 and +50 mm of water.
The tympanoossicular chain vibrates optimally when the pressure is the same on either side of the eardrum. This same pressure is provided by a normal functioning of the Eustachian tube that opens regularly, both during periods of sleep during periods of sleep. When the Eustachian tube malfunction, it hinders the ossicular vibration. The tympanogram is more or less reduced in amplitude and more or less centered toward the negative pressure. If no treatment is given at that stage, gradually the Eustachian tube will no longer function at all, the lining of the body of the ossicles will begin to secrete a mucous and fluid will accumulate behind the eardrum: it is a serous otitis.
The tympanogram is then completely flat.
If tympanic perforation can not make the seal in the ear canal when the Eustachian tube function.
However, if we manage to make the seal and that there is a perforation that sign an Eustachian nonfunctional or incompletely functional.
Search stapedial reflexes:
Search stapedial reflex is done by subjecting the ear to loud sound, typically 70-80 dB hearing threshold, having taken the precaution of putting in conditions of equal pressure on both sides of the eardrum .
Under these conditions, if acoustic reflex, a frank observed deviation of the needle of the meter, deviation decreasing amplitude gradually as the loudness decreases.
The acoustic reflex is related to a contraction of the muscle of the stirrup under the control of the facial nerve. It is a bilateral reflex.
There are four types of acoustic reflex to look for: the right acoustic reflex in response to sound stimulation on the right or the left and even the left stapedial reflex in response to sound stimulation on the left side or the other side . We’ll collect stapedial reflexes ipsilateral and contralateral left and right left and right.
We search for the frequencies 500, 1000 and 2000 Hz, the acoustic reflex obtained on frequency 4000 Hz for obtaining longer random. It is very convenient to include the stapedial reflexes on the audiogram itself.
It shall include those by large I, where it is a refl exe stapédien ipsilateral and a large C when it comes contralateral acoustic reflex.
It is indicated on the side of the auditory stimulation. This writing is convenient because it can immediately locate at a glance the acoustic reflex relative to the tonal thresholds.
These results are very useful in differential diagnosis of deafness from the inner ear, called endocochléaires and deafness from the auditory nerve, tell retrocochlear. If hearing decrease endocochlear, stapedial reflexes are collected at normal levels while they are high thresholds or disappear for infringement retrocochlear.
Tonal audiometry:
Both the impedance is a simple act of realization as pure tone audiometry is a difficult act, which requires a lot of experience and a heavy and expensive infrastructure since it must take place in a soundproof booth.
It consists of the construction of two air and bone curves.
For the realization of the air curve, the patient has a headset through which different sound frequencies offered to him at varying intensities. He is asked to raise a finger when he hears the sound and lower it when no longer be heard.
Bone curve is performed with a vibrator placed on the mastoid of the side to be tested. It is very difficult to perform because it requires a contralateral mute. It has to be her enough magnitude to mute the contralateral ear, but its intensity at the same time should not be too strong to not sound on the ear tested. In cases of bilateral hearing loss, these rules muting can result in very complex situations.
Sounds tested in pure tone audiometry are between 125 and 8000 Hz. This is the frequency area where our hearing is most efficient. The human ear hears 20 to 20,000 Hz, but in the zone of very serious or very high frequencies, it is much less efficient. In this frequency range, 125-8 000 Hz an area is even more important, the one that goes from 500 to 2000 Hz, or 500 to 4000 Hz. It is essential for the understanding of the word and it is designated under the term conversational area.Any hearing loss at this level is very detrimental in terms of speech understanding.
The subject’s answers are plotted on a graph with x-axis tested frequency axis and the decibel loss (Box 2).
Box 2. Levels of deafness
light
auditory threshold between 0 and 40 dB
Average
auditory threshold between 40 and 70 dB
Severe
hearing threshold between 70 and 90 dB
deep
hearing threshold greater than 90 dB
A normal subject has superimposed air and bone areas which lie between – 5 and 10 dB over the entire spectrum.
There are two types of hearing loss:
– Deafness of transmission: bone curve is normal and only airline curve drops. The space between the two curves is referred to as the Rinne;
– The urdités s perception: the air and bone curves are superimposed and lowered both.
Deafness transmissionnelles concern the external and middle ear pathologies and perceptive deafness affect sensory pathologies related to an impairment of the inner ear or the auditory pathways.
Mixed hearing loss have both transmissionnels and perceptive characters. It is observed more often transmissionnel a type of deafness on the area and serious bone curve joined the Air curve and they are both on the deficit in acute middle zone.
It is usually chronic otitis which, over the years, resulted in a deficit of inner ear, they say it is labyrinthisée.
Bone curve has the great advantage to inform us about the state of the inner ear (Box 2). transmission or mixed hearing loss are likely a surgical procedure that could improve the listening situation. However, sensorineural deafness are not operable outside course of the removal of a neuroma VIII but in this case there is no question of recovering the sensory deficit.
Speech audiometry:
The tests of speech understanding are to ask the patient to repeat words at different sound intensities.
There are many speech intelligibility tests, some may use phrases, other disyllabic words and other words consist of three phonemes (lists Lafon). Of these tests, most commonly used is composed of disyllabic lists Fournier. It has the advantage of testing the entire auditory system from the external ear up to and including the cortex, the patient can guess quite a missing syllable he has not heard. We are therefore very close to the actual hearing conditions.
Lafon’s lists are also used in many specialized environment including cochlear lists because they help to identify a privileged way the distortions due to a malfunction of the inner ear.
The advantage of voice tests is to stick as close to the patient’s complaint in order to quantify and analyze it. They will allow to know the level of social embarrassment caused by this hearing loss and the importance of understanding distortions.
Deafness is a more ancient, more understanding of the distortions are superimposed, resulting in phonemic regression, the increasing difficulty understanding speech even if the hearing threshold itself does not deteriorate.
These tests can sometimes highlight distortions of understanding of central origin.
These are, of course, much more difficult to improve by wearing a hearing aid, for example.
these voice tests can be performed in silent environment, but it is also often useful to perform in a noisy environment to reproduce again the closest conditions difficulties the patient reports.
Additional tests:
Auditory evoked potentials of the brainstem:
Auditory evoked potentials of the brainstem (PEA) are a kind of electroencephalography of the auditory pathways from the inner ear to and including the brain stem. It is an atraumatic examination in which electrodes are placed on each mastoid, one on the front and one vertex. Repetitive sound stimuli type clicks are sent and collected in response vector by averaging a series of five waves. The waves I and II are from the auditory nerve, the wave III of the pontine olive and wave V of the lateral lemniscus.
The exam is essential to achieve a unilateral sensorineural hearing loss because it eliminates a possible neuroma VIII.Indeed, if an inner ear deafness, these waves are delayed due to hearing impairment, but the conduction time, the time between waves I and III and the waves I and V include, remain constant. However, in case of violation of the auditory nerve, the conduction slowing and these delays are getting longer.
There is talk of retrocochlear reached. The diagnosis of retrocochlear affect the evoked potentials must lead the practice of MRI in search of a neuroma VIII.
These evoked potentials are also the means to achieve an objective determination of the hearing threshold on acute area. Indeed, when the stimulation intensity decreases gradually earliest waves is lost I and II, but retains wave V up to 10 to 20 dB of the threshold on the area 2000 to 4000 Hz.
Finally, these evoked potentials are useful in the diagnosis of small violations of the tumor or vascular brain stem. There are retrocochlear violations that are not related neuroma VIII. They may reflect, for example, diabetic neuritis or a presbycusis which preferably reaches the central lanes.
Radiology:
Instead of radiology in the ear pathologies is especially important in the middle ear pathologies. The possibilities of high-resolution scanner used to study very fruitful way the state of the ossicles or the labyrinth.MRI is it reserved for the study of the auditory nerve whether screening neuroma VIII, but also a possible vascular loop coming to bear on the auditory nerve.
Videonystagmography:
The study of balance or videonystagmography is indicated when the hearing decline is associated with dizziness or balance disorders.
Doppler cervicoencéphalique:
Apart from exploring a pulsatile tinnitus, it has virtually no indication in the hearing pathology.
ETIOLOGY:
Sudden deafness:
by sudden deafness denotes a sensorineural hearing loss installed in less than 24 hours.
It should always be considered an emergency. Until recently, it required more often the patient’s hospitalization for intravenous fluids and carbogen breathing. The current attitude is to return to this treatment protocol that does not appear to be a decisive criterion for recovery.
Nevertheless, sudden deafness currently still requires the establishment of an emergency treatment to try to recover the deficit with corticosteroids and vasodilators high dose or anticoagulants.
Unilateral in most cases, preferably reaching the high notes, all degrees of deafness are possible from mild hearing loss to total deafness, or deafness.
Evoked potentials should ensure that the origin of the cit endocochlear challenge. Sudden deafness, although it recovered may be associated with a neuroma VIII by vascular compression and retrocochlear abnormalities PEA therefore needed MRI.
A sudden deafness on the bass frequencies may be the first manifestation of a disease IOP. Diagnosis can be difficult especially in the absence of associated vertigo.
Chronic deafness:
Conductive hearing loss:
Plug of earwax:
The earwax is an obvious cause.
If it appears easily accessible, it can be removed with forceps. However, if it appears deeply at the bottom of the pipe or if it gives the impression of being heterogeneous and brittle, it is better to practice an ear wash. Before introduction of water into the pipe, we must ask the patient without his knowledge of tympanic perforation since introducing water into a middle ear through a tympanic perforation may be a source of infection. When in doubt or, a fortiori, known perforation is then performed by aspiration at best under a microscope.
Tubal catarrh and OME:
Catarrh tubal serous otitis and diseases are common in children, less common in adults. The diagnosis is made by the impedance shows a tympanogram deflected to the negative pressures in case of tubal dysfunction and a flat tympanogram in case of serous otitis. The hearing assessment clarifies the impact on hearing.
Catarrh tubal justifiable anti-inflammatory therapy or corticosteroid therapy.
It can also be responsive to a combination aerosol anti-inflammatory and local disinfectants.
The OME is amenable to treatment with corticosteroids. If it is ineffective, it can lead to the placement of a tympanostomy tube that can suck the accumulated mucus behind the eardrum and restoring good hearing by making permanent ventilation of the body of the ossicles.
In adults, the recognition of a tubal catarrh or recurrent unilateral serous otitis must practice a radiological assessment of the nasopharynx looking for a mechanical barrier to tubal mobility.
Chronic otitis:
The evidence puts otoscopy tympanic alterations. It may be a simple scar appearance of the eardrum: buffy appearing and thickened, more or less retracted, having lost its translucent character, sometimes with limestone plates. It can also be a tympanic perforation which must observe the characteristics. The criteria are first note its size, marginal or not, if it is dry or oozing, just a mucous or purulent fluid. It is always useful to make a small pattern in the patient record, allowing in successive otoscopy to monitor.
If the perforation is large, it is possible to see through it the cash fund that is to say, the posterior wall of the body of the ossicles whose characteristics we like, that of a normal mucosa or more often these cases of congestive edematous mucosa.
Sometimes, through this perforation a whitish mass more or less suggestive of cholesteatoma is observable.Cholesteatoma met at the ear is most often the result of chronic otitis old. This is a kind of runaway mucosa begins to proliferate and destroy the bones. The danger is that the progression of destruction which can affect bone walls of the box to the meninges.
This clinical evaluation is completed by the hearing assessment which, besides the size of the deficit indicates the status of the inner ear, knowing that if a surgical procedure is planned, we can not hope to recover that part transmissionnelle the deficit. This report is also supplemented by a scanner focused on the middle ears.
The warming periods for these chronic ear infections are treated with antibiotics or topical antibiotics, but watch most ear drops are cons-indicated in cases of eardrum perforation, since they have ototoxic antibiotics and can lead to permanent hearing loss or deafness sensorineural kind by damage to the inner ear.
Outside periods of warming, there is the problem of closing the fund so ossicles to prevent secondary infections and also to try to restore a better hearing.
It is the role of the tympanic grafts or tympanoplasties possibly accompanied by restoration actions of the ossicles.
Otosclerosis:
Otosclerosis is a transmissionnelle pathology in which there is a blocking of the caliper. This is a most often hereditary disorder of an enzymatic nature which results in calcification of the membrane connecting the yoke to the inner ear and allowing the transmission of the ossicular vibration to the cochlea.
Usually bilateral, or mixed nature of transmissionnelle, normal otoscopy, she frequently reaches women.Hyperestrogenism periods, pregnancy and lactation, are particularly dangerous for the evolution of this deafness.
If pure conductive hearing loss, good results are obtained by operating otosclerosis.
The procedure involves removing the caliper blocked and replaced with a small Teflon® piston which restores the transmission of vibration of the ossicles to the inner ear.
If mixed reached, that is to say which is associated particularly acute neurosensory deficit to an area, it must weigh the benefits of the intervention.
The situation bone curve is essential to make the decision of the intervention.
Achievement traumatic ossicular chain:
Traumatic damage to the ossicles, dislocations or fractures, could pass unnoticed in the immediate aftermath of trauma.
They can be identified by the scanner.
There may be surgical repair possibilities must still weigh the benefits, the hope of hearing recovery to be very much higher than the possible risk of intervention.
The external ear malformations and / or medium are sometimes obvious diagnosis in case of ear aplasia, for example, but they can be more discreet and be revealed by the scanner asked before a finding of transmissionnel deficit.
Sensorineural hearing loss:
Presbycusis:
Presbycusis or hearing loss due to age is a bilateral hearing loss of perception, usually symmetrical. She reached first high frequencies, then the years extends to the center frequencies or the low frequencies. Such aging phenomena are not confined to the inner ear and are more or less extended to the central portion
the auditory pathways. With age, the memory access
is longer, time analysis of speech is slower, also a frequent remarks in elderly patients is that young people speak too fast for them or articulate wrong. Indeed, the loss of acute causes loss of frequency discrimination and, therefore, a less clear perception of speech.
This decrease of hearing is very slow and very sneaky installation, the patient gets used gradually to not hear a number of sounds without noticing it can happen to social isolation, very harmful to their development .
It would be wise to systematically carry out a hearing assessment at the age of 65 to take stock before the big age.This would take the early essential as is the wearing hearing aids for re-stimulate the auditory pathways. This is a real réafférentation the auditory system. It is important that it be implemented early, while the patient is still able to adapt to the new world of sound and returned before irreversible distortions of understanding will be installed, making the port the ineffective prosthesis .
Much progress has been made in the last decade in the field of hearing aids.
Unfortunately, the equipment keeps a connotation of aging and the patient is rarely immediately favorable. This is the role of doctor and specialist convince gradually interest to rework the auditory pathways. In general, the equipment, apart from particular situations, should be bilateral to restore the stereo, allowing a better understanding in noisy environments or in the presence of several speakers.
Acoustic trauma:
The acoustic trauma is unfortunately becoming more common, because we are very noisy civilizations. It is characterized by an attack of acute area with generally rise on the higher frequencies. It can be bilateral and symmetric. In contrast, in the hunter, it is marked on one side with the right-handed fighter, the right ear by a shadow effect, is protected during firing, and it’s left ear that suffers more (the opposite in the shooter left).
Let us recall that deafness linked to a noisy professional practice workshop for example, is compensated under the table 42 of occupational diseases.
Neuroma VIII:
Neuroma VIII typically carries a unilateral sensorineural hearing loss with generally very clear understanding voice distortion and the disappearance or threshold elevation corresponding stapedial reflexes. It can also be revealed by dizziness while performing a challenge cit uncompensated vestibular caloric test.
Currently, we are able to diagnose very early neuroma VIII by both auditory evoked potentials and possibilities of discrimination of MRI. This has changed our therapeutic approach, intervention being proposed at the outset that when it comes to a large neuroma or able to have significant consequences, especially if it is near the brain stem. In other cases, especially when the neuroma is very small, simple monitoring is lawful.
She then made both on the hearing assessment, evoked potentials and imaging.
In exceptional cases, it may be a more general athologie under Recklinghausen’s disease, with neuromas that reaches the various cranial nerves and can in this case reach two auditory nerves.
Pressionnelles diseases of the inner ear:
The pressionnelles diseases of the inner ear, which is emblematic disease Meniere’s disease realize unilateral sensorineural hearing loss, recurrent, preferably reaching the grave area, accompanied by full ear sensation and perception of sound distortion. These are crises of a few hours to days. Deafness is-limited at first and then, over time, the threshold gets less and less and permanent deafness sets in. In Meniere’s disease, deafness these episodes are accompanied by rotary vertigo very disabling, unexpectedly occurred, immobilizing the patient several hours.
The treatment of the crisis consists of steroids or diuretics, anti-vertigo if necessary.
Toxic deafness:
Toxic deafness reach the inner ear and are therefore in most cases irreversible.
With the exception of acetylsalicylic acid, the toxicity seems closely related to the dose, all subjects are equal before the risk and there is individual susceptibility.
Main ototoxic molecules are aminosidiques antibiotics, quinine and derivatives thereof, some diuretics, benzenes and derivatives.
Autoimmune deafness:
In patients with bilateral sensorineural hearing loss, often accompanied by tinnitus and dizzy episodes, sometimes initiated by a sudden deafness, a number of systemic diseases must be sought:
– Deafness is at the forefront in Cogan’s syndrome (cochleovestibular reached, interstitial keratitis sometimes only found in the interrogation, rarely or aortic insufficiency associated vasculitis);
– Deafness is frequent and serious in relapsing polychondritis (see red ear) and Wegener’s granulomatosis (see Chapter polyarthralgia);
– Deafness is rare but sometimes severe in the classic connective essentially sicca Sjogren’s syndrome and systemic lupus erythematosus. In the latter case, look for antiphospholipid antibodies, because the deafness mechanism is vascular;
– In the absence of systemic disease and explanation of this bilateral sensorineural hearing loss, we have to rule systematically search for antinuclear antibodies, antiphospholipid antibodies (anticardiolipin and lupus anticoagulant lupus), the cytoplasmic antibodies (ANCA) Ab glomerular basement antimembrane. Search for Ac anticollagène does not seem very useful and the search for Ac anticochlée not done routinely in France
Vascular deafness:
The labyrinthine artery is a fragile artery arises from the posterior inferior cerebellar and irrigates both the cochlea and vestibule.
Its bite can explain sensorineural hearing loss. We must therefore search for antiphospholipid syndrome, a defi cit in protein C or protein S, a mutation in the prothrombin gene (Factor II), hyperhomocysteinemia and generally all causes of genetic thrombophilia.
Genetic deafness:
Genetic deafness is becoming better known. The most severe forms are screened before a deafness in children, in association or not with other anomalies.
In adults, the diagnosis is usually suspected in premature presbycusis. So this is a bilateral sensorineural hearing loss and substantially symmetrical whose genetic character is evoked by the questioning which is the notion of a family deafness. The finding of a tonal deficit of the same profile in several members of the family is a strong argument for diagnosis.
If deafness associated with diabetes and / or loss of consciousness, we must think of a mitochondrial cytopathy. Asked a brain MRI, and a search of mutation or deletion of mitochondrial DNA (maternally inherited).