Hearing Loss

Hearing impairment / deficits in early childhood can have a lifelong underdevelopment of language comprehension and expression entail. The severity of the disability is determined by

More than 10% of people in the US have some degree of hearing loss that affects their daily communication, which makes it one of the most common sense errors. About 1/800 to 1/1000 newborns is strong to severe hearing loss at birth, and two to three times as many children are born with a hearing impairment easier. In childhood, in addition, a moderate to severe (acquired) developed hearing loss in 2-3 / 1000 children. Young people are at risk from excessive noise and / or head injury. The typical experience of older people that their hearing is deteriorating (presbycusis) is likely related to a combination of aging, noise exposure and genetic factors. It is estimated that about 30 million people are exposed daily in the US harmful noise levels. Hearing impairment / deficits in early childhood can have a lifelong underdevelopment of language comprehension and expression entail. The severity of the disability is determined by the age when the hearing loss has occurred, the kind of the deficit (duration, frequencies and affected the degree) the susceptibility of the individual child (for. Example, by co-existing visual impairment, mental deterioration, primary language deficits , inadequate linguistic environment) are the hardest hit children still additionally have other sensory, linguistic or cognitive weaknesses. Pathophysiology hearing disorders can be classified as conductive or sensorineural hearing loss (sensorineural hearing loss), or as a mixed form of both. A conductive hearing loss occurs when the injury to the external auditory meatus, the tympanic membrane or middle ear prevent a successful transmission of sound waves to the inner ear. A sensorineural hearing loss or a sensorineural hearing loss, by inner ear injury or by Hörnervenläsionen (VIII cranial nerve, i.e., neural…) Conditionally (see Table: Differences between sensory and neural hearing loss) (i.e., sensory..). This distinction is important because a sensory hearing loss is sometimes reversible and is rarely life-threatening. A neural hearing loss is rarely curable and can (usually cerebellopontine angle tumor) start from a potentially life-threatening brain tumor. Mixed forms may be by severe head injuries caused (with / without skull or temporal bone fracture), chronic infection, or one of the many genetic disorders. They also occur when a sensorineural hearing loss (mostly due to a middle ear infection) is still superimposed by a transient conductive hearing loss. Differences between sensory and neural hearing loss test Sensory hearing loss Neural hearing loss, speech discrimination (sfähigkeit) Moderate deterioration Strong deterioration discriminated Nation (sfähigkeit) at increasing volume / intensity is improved normally up to a certain extent, depend on the severity and distribution of the loss of sensory elements worsenedRecruitment in which the perception of sound, especially at high sound levels presence Misses is exaggerated, Acoustic Reflex attenuation in the acoustic reflex response absent or weak presence waveforms auditory evoked brainstem is reduced over time during a measurement Good formed with normal latencies for mild to moderate hearing loss ; for heavier losses reduced Missing or otoacoustic with abnormally long latency emissions Missing presence etiology deafness can be congenital (see table: causes of congenital deafness *) or acquired (see table: causes of acquired hearing loss) be develop gradually or suddenly occur (sudden deafness , sudden hearing loss), temporarily or permanently, unilateral or bilateral, or slightly pronounced. The drug-induced ototoxicity is discussed elsewhere (drug-induced ototoxicity). The most common causes are as follows in general: Zeruminalpfropf noise aging infections (va in children and young adults..) Especially in the elderly is often earwax (Zeruminalpfropf) the reason a treatable challleitungsschwerhörigkeit. Foreign bodies that lay the ear canal, are occasionally a problem in children, both because of their presence and because of the damage that may occur accidentally in their removal. Noise may cause a sudden or gradual loss of hearing. An acoustic trauma, the hearing loss resulting from exposure to a single extreme noise results (z. B. a delivered near shot or explosion). Some patients also develop tinnitus. The hearing loss is typically temporary (unless there is a pressure wave that destroyed the eardrum and / or the ossicles). With noise-induced hearing loss, the loss> 85 decibels developed over time due to chronic exposure to noise (dB pitches). Despite individually different noise sensitivity of each is almost deaf when he was exposed over a period of time sufficient to loud noise. Repeated exposure to loud noise but ultimately leads to loss of hair cells in the organ of Corti. is typical of noise-induced hearing loss that he makes at first at frequencies of 4 kHz noticeable and gradually spreads to lower and higher frequencies with continued noise exposure. Unlike a sensorineural hearing from most other causes to noise-induced hearing loss can have less effect at 8 kHz than 4 kHz. Aging, together with noise and genetic factors is a risk factor for the gradual reduction of age-related hearing loss hearing the called Presbyacusis. Presbycusis due to a combination of sensory cells (hair cells) and neuronal loss. The research also indicated strongly suggests that early noise pollution accelerates age-related hearing loss. In age-related hearing loss, higher frequencies are more affected than lower. Dieakute Otitis media is a common cause of a transient mild to moderate hearing loss (v. A. In children). Without treatment the consequences of acute otitis media and chronic otitis media (as well as the rare suppurative labyrinthitis) may cause permanent hearing loss, especially if forms a cholesteatoma. The secretory otitis media occurs in different ways. On almost all the episodes of acute otitis media after a period of 2-4 weeks followed by a secretory otitis media. A secretory otitis media can also dysfunction of the Eustachian tube (e. As caused by a cleft palate, benign or malignant tumors of the nasopharynx or rapid changes in the external air pressure, such as during the descent from a great height, or by the rapid rise during the dive occur). Autoimmune diseases can lead to sensorineural hearing loss and lead to other symptoms and complaints in all age groups. Causes of congenital deafness * affected anatomical structure etiology † conductive hearing appearance and middle ear Genetically development According (z. B. ossikuläre fixation) Idiopathic (malformation of unknown cause) Drug-induced malformation (z. B. thalidomide) Sensory inner ear Genetically Idiopathic (malformation of unknown cause) K ongenitale infection (eg. As rubella, cytomegalovirus, toxoplasmosis, syphilis) Rh incompatibility anoxia ototoxic medication the mother (eg. As for TB or severe infection) Drug-induced malformation (z. B. thalidomide) Neural CNS anoxia Idiopathic (malformation of unknown cause) Genetically Congenital infection (z. B. rubella, cytomegalovirus, toxoplasmosis, syphilis) neurofibromatosis (type 2) hyperbilirubinemia * In a number of cases with congenital hearing loss, it may be mixed forms, d. H. Conductive hearing with sensory neural hearing loss with or without. † list of causes in descending order of frequency. Causes of acquired hearing loss cause * Suspicious findings diagnostic approach † Outer ear (conductive hearing loss) obstruction (eg., Caused by ear wax, foreign bodies, otitis externa, or, rarely, tumor) visible during the investigation Otoscopy Clinical evaluation of the middle ear (conductive hearing loss) otitis media (Secretory) hearing loss can vary Sometimes dizziness, pain or fullness in the ear Usually abnormally looking eardrum often acute otitis media or other causal event in the history Otoscopy Audiological examination with Tympanogram otitis media (chronic) ‡ Chronic ear discharge normally visible perforation granulation or polyp in the ear canal cholesteatoma Sometimes otoscopy in cholesteatoma CT or MRI ear trauma Obviously ‡ based on history often visible perforation of the tympanic membrane, blood in the channel or after the Eardrum (if intact) Otoscopy Clinical evaluation Otoskleroses ‡ family history age of onset in the 20s to 30s Slowly progressive audiogram, tympanogram and otoscopy tumors (benign and malignant) Partial loss often lesion visible during otoscopy CT or MRI inner ear (sensory loss) Genetic Diseases (z. B. connexin-26 mutation, Waardenburg syndrome, Usher syndrome, Pendred syndrome) Occasionally, positive family history (but generally negative) connexin 26 mutations account for the vast majority of cases of non-syndromic hearing loss and should initially investigated will be occasionally include white forelock or different colored eyes to the Waardenburg syndrome. The loss of eyesight and hearing may on Usher syndrome indicate Clinical evaluation genetic testing CT and / or MRI noise exposure In general, apparently due to a history of clinical investigation presbycusis> 55 years for men,> 65 for women Progressive, bilateral loss of normal neurological examination clinical evaluation ototoxic drugs (eg. aspirin, aminoglycosides, vancomycin, cisplatin, furosemide, ethacrynic acid, quinine) drug history Bilateral Ver loss Variable vestibular symptoms renal failure Clinical evaluation infections (eg. As meningitis, purulent labyrinthitis) Obvious infection in the history Symptoms that use during or shortly after infection Clinical evaluation autoimmune diseases (eg. As RA, SLE) arthritis, rash Uncommon a sudden change in vision or eye irritation pain or swelling in cartilage often known disease serological tests Meniere’s syndrome episodes of unilateral, fluctuating hearing loss, accompanied by aural fullness, tinnitus and dizziness gadolinium MRI to rule out a tumor Barotrauma ‡ (with perilymphatic fistula) Abrupt change of pressure (z. B. Scuba Diving, faster decline in aircraft) or blow to the ear canal in the history Occasionally, severe ear pain or dizziness tympanometry and balance function tests Surgical exploration with persistent dizziness head trauma (‡ with Schädelbasisbruch or cochlear concussion) severe injury in prehistory may vestibular symptoms, facial weakness Uncommon blood behind the eardrum, cerebrospinal fluid leakage, ecchymosis over the mastoid CT or MRI CNS (neural loss) cerebellopontine angle tumors (z. B. Akustikusneurin om, meningioma) Unilateral hearing loss, tinnitus often Vestibular with anomalies Occasionally deficits of the facial nerve or the trigeminal nerve gadolinium MRI demyelinating disease (eg. As multiple sclerosis) Partial loss multifocal arrival and decongestant symptoms MRI brain compartments occasionally lumbar puncture * list in descending order of frequency. † All patients underwent otoscopy and a hearing test should be performed. ‡ A hybrid of conductive and sensorineural hearing loss (sensorineural hearing loss) may also be present. TM = eardrum. Pitch sound intensity and pressure (the physical correlates of loudness) are measured in decibels (dB). A dB is a dimensionless quantity that compares two values, and is defined as the logarithm of a quotient from a measured and a reference value, multiplied by a constant k: dB = k log is (Vmeasured / Vref) by convention, as a reference value of the volume of the quietest 1000 -Hz tone taken, nor can hear the young people with healthy ears. * This tone can be used as sound pressure level (N / m2) or sound intensity (watts / m2) can be specified. Since the sound intensity is equal to the square of the sound pressure, is the constant (k) for the sound pressure level 20, 10 for the sound intensity Accordingly, means any increase of 20 dB, a 10-fold increase of sound pressure level, but a 100-fold increase in sound intensity. The dB values ??in the table below give only a rough idea of ??the risk for a hearing loss. Some of them are dB values ??of the sound pressure level (based on N / m2), while others represent the dB peak or dB values ??on the A scale (a scale that holds the frequencies that are most dangerous to the human ear ). dB Example 0 weakest, to the human ear audible sound 30 Whispering silence like in a library 60 Normal conversation, sewing machine, typewriter 90 lawn mowers, Till, truck traffic (load capacity without soundproofing † maximum of 90 dB for 8 hours / day) 100 chainsaw, hammer drill, snowplow (perm ssige load without sound insulation than 2 h / day) 115 sandblasting, loud rock concert, car horn (permissible load without sound insulation than 15 min / day) 140 gun muzzle flashes, jet aircraft (noise causes pain; even brief exposure of unprotected ears harmful; itself) 180 missile launcher * Since human ears react with earflaps still hearing impairment possible different sensitivities to different frequencies of Rerferenzwert for each frequency changes in the audiometric examination. The account of the thresholds specified in audiograms. The normal hearing threshold, regardless of their actual sound pressure level (SPL) always 0 dB. † Legally prescribed (by the US federal government) guideline; but if the noise exposure is not only in the short term, is recommended for all noise levels> 85 dB ear protection. Clarification The study is for the detection and quantitative detection of hearing loss and to clarify the etiology (especially reversible causes). Screening Most adults and other children notice a sudden hearing loss, and when newborns do not respond in the first weeks of life to the voice of their caregivers or other sounds, which is suggestive of a severe hearing loss. A progressive Höverlust and nearly every type of hearing loss in infants and young children must be detected by screening. To permit by linguistic promote optimal language development, these checkups should already begin after birth (Screening: hearing tests). At each suspected hearing impairment immediate transfer is independent from the time attached to a specialist. Without screening, a severe bilateral hearing loss would probably not discovered before the age of two; mild to moderate degree forms or serious unilateral hearing loss often remain even until they reach school age unerkannt.Anamnese The history of the disease process should take into account how long the hearing loss is, as he began (z. B. gradually acute) if he unilaterally or both sides and whether sounds are distorted (z. B. music sounds dull or lifeless) or if difficulties with respect to the linguistic ability discriminated nation exist. The patient should be asked whether the hearing loss was followed by an acute event (eg. As head injury, exposure to noise, barotrauma [in particular a diving accident] or after taking medication). Important accompanying symptoms are other otologic symptoms (eg. As ear pain, tinnitus, ear discharge), vestibular symptoms (eg. As disorientation in the dark, dizziness) and other neurological symptoms (eg. As headaches, weakness or facial asymmetry, abnormal taste , fullness in the ear). In children are important accompanying symptoms delays in speech or language disorders, visual changes or delayed motor development. In a study of organ systems should be trying to determine the impact of hearing loss on the patient’s life. The history should earlier, possibly causative diseases, including CNS infection, repeated ear infections, chronic noise exposure, head trauma, rheumatic diseases (eg. As RA, lupus) and a family history of hearing loss observed. A drug history should specifically check the current or past use of ototoxic agents. In young children should be established by a birth histories if there are any intrauterine infections or complications at birth gab.Körperliche investigation, the focus is on the investigation of the ears and hearing as well as a neurological exam. The pinna is examined for obstruction, infection, congenital malformations and other lesions. The eardrum is to perforation, drainage, otitis media (pus in the middle ear through the tympanic membrane is visible) investigated and cholesteatoma. During the neurological examination, special attention must be paid to the II. To VII. Cranial nerve and the vestibular and cerebellar function because abnormalities in these areas are often associated with tumors of the brain stem and cerebellar pontine angle. In Weber and Rinne test using a tuning fork to delineate a sensorineural from a sensorineural hearing loss. When Weber test the foot of a vibrating 512 Hz or 1024 Hz tuning fork is placed in the crown center, and the patient indicates in which ear the sound is louder. In unilateral conductive hearing loss, however it is in the affected ear, with one-sided sensorineural hearing loss in the healthy ear louder – because the tuning fork both inner ears equally stimulated, but the patient perceives the stimulus only in the unaffected ear. With the Rinne test bone and air conduction are compared in hearing. Since outer ear and middle ear are bypassed in the bone conduction, it can be determined whether the inner ear, VIII. Cranial nerve and central auditory pathways are intact. First, a vibrating tuning fork with the foot is held against the mastoid (for testing the bone conduction); when sound is no longer heard, one raises the tuning fork from the mastoid high and holds her still vibrating tines close to the ear (for testing the air line). Normally, the sound of the tuning fork is again audible again – which shows that air more conductive than bones. With a conductive hearing loss, the relationship is reversed, and sounds are perceived louder on the bone than through the air line. In a sensorineural hearing loss, although air and bone conduction are reduced, but the air line remains relatively lauter.Warnzeichen findings are of particular importance unilateral sensorineural hearing abnormalities of the cranial nerves (except hearing loss) Rapidly deteriorating hearing loss interpretation of the findings, many causes of hearing loss (z. B. cerumen, injuries, serious noise pollution, infectious sequelae, drugs) are due to the history and because (of test results see table: causes of acquired hearing loss) readily apparent. Associated findings are helpful in the diagnosis of the remaining small number of patients in whom no clear cause can be found. Patients exhibiting focal neurological abnormalities, special importance must apply. The V or VII. Cranial nerve or both are often affected by tumors, which include the VIII. Cranial nerve with. A loss of sensation in the face and a weak jaw closure (v) and a hemifacial weakness and Geschmacksnomalien (VII.) Indicate a lesion in this area. Symptoms of autoimmune diseases (eg. B. joint swelling or pain, eye inflammation) or impaired renal function may suggest these disorders as a cause. Maxillofacial malformations may indicate a genetic abnormality or an abnormality in the development. In children with delayed speech or language development or school difficulties, the hearing should be investigated. Even mental impairment, aphasia and autism must be etiologically considered. Delayed motor development could indicate an imbalance that often include a sensorineural hearing loss einhergeht.Tests Among the tests: audiological tests occasionally MRI or CT Audiological tests are all persons who show a hearing loss, required; These tests usually include the measurement of Reintonhörschwellen with air and bone conduction speech perception threshold Sprachdiskriminationsfähigkeit tympanometry acoustic reflex testing The information obtained will also help to decide whether a more precise distinction between sensory and neural hearing loss is required. Using the pure tone audiometry can be measured quantitatively with a hearing loss. With an audiometer certain sound frequencies (pure tones) supplies in different sound intensity, the patient’s threshold of hearing (i.e.,.. Has to how loud a tone to be perceptible to him) is determined for each frequency. For tones of 125 or 250-8000 Hz air line are (on headphones) and up to 4 kHz bone conduction tested (with an oscillator on the mastoid or end) at each ear separately. The graphic representation of the test results in so-called. Audiograms (audiogram of the right ear in a patient with normal hearing.) Differences between the hearing threshold of the patient and the normal values ??for the individual frequencies can be read. This difference is expressed in dB (pitches). Than normal hearing threshold a Hörlevel (Hl) is considered of 0 dB; is the patient’s hearing threshold> 25 dB, considered a loss. If very loud test tones are required with a severe hearing loss, they can be heard in the other ear. In solchen Fällen wird ein maskierender (Vertäubungs-)Ton, meist ein Rauschen, in das nicht getestete Ohr eingespielt, um es auszuschalten. Bei der Sprachaudiometrie werden die Verständlichkeit von Gesprochenem (Sprachrezeptionsschwelle, SRS) und die Worterkennung bewertet. Die SRS ist ein Maß für die Lautstärke, ab der Gesprochenes verständlich wird. Um die SRS zu bestimmen, trägt der Untersucher dem Patienten eine Liste von Wörtern in bestimmten Lautstärken vor. Diese Wörter haben in der Regel zwei gleich betonte S

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