hearing impairment
Introduction
Introduction to hearing impairment It refers to the qualitative or functional abnormalities of the nerve center generators at all levels of the sound system, the sensory sound, and the comprehensive analysis of the sound in the auditory system, resulting in different degrees of hearing loss. It is customary to call deafness. It is called sputum only if the hearing is severely degraded, and it is manifested that the patient cannot hear any words in both ears. If the hearing loss does not reach this severity, it is called hearing loss. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: deafness, tinnitus
Cause
Causes of hearing impairment
Disease lesions (25%):
Any lesions confined to the outer and middle ear, and affect the guiding function, are conductive deafness. Such as the developmental deformity of the outer and middle ear, obstructive diseases of the external auditory canal, inflammatory or non-inflammatory diseases of the middle ear, ear sclerosis, etc., can cause conductive hearing loss.
Dysfunction (15%):
Middle ear lesions coexist, and hearing impairment caused by sound conduction and sensation is called mixed deafness. The cause of mixed deafness may be a lesion that simultaneously damages the sound and sensory system of the ear, or may be caused by a dysfunction of the middle ear and the inner ear or the auditory pathway, respectively.
2. Classified by disease time
(1) Congenital deafness: including congenital atresia of the external auditory canal, middle or inner ear malformation, various deafness caused by pregnancy and perinatal period.
(2) Acquired deafness: including all kinds of conductive sputum in the outer ear and middle ear, such as posterior atresia of the external auditory canal, suppurative otitis media, external and middle ear tumors, various trauma and otosclerosis; in sensorineural hearing loss Including various infectious diseases caused by various infectious diseases, toxic sputum, labyrinthitis, acoustic neuroma, auditory neuropathy, senile sputum and functional sputum caused by mental factors.
Prevention
Hearing impairment prevention
Pregnancy check: During pregnancy, especially during the first three months, women are often at the stage of fetal inner ear development. Care should be taken to avoid contact with ototoxic drugs, physical radiation, viral infection, carbon monoxide poisoning, etc. factor.
Treatment of systemic diseases: Control the systemic underlying diseases that may cause deafness such as hypertension, diabetes, kidney disease, etc., and rationally use the medicine to avoid involving the hearing function.
Complication
Hearing impairment Complications, deafness, tinnitus
For children with sensorineural hearing loss, the additional burden of conductive hearing loss can severely reduce their ability to discriminate. Hearing loss affects children with additional sensory, linguistic and cognitive impairments more severely than other healthy children.
Common clinical symptoms of hearing impairment include tinnitus, hypersensitivity, deafness, auditory hallucinations, and hearing loss.
Symptom
Hearing Impairment Symptoms Common Symptoms Pathological Auditory Adaptation Cannot Understand Others and Self... Fu Cun Phenomenon Central Deafness Ear Vestibular Auditory Imbalance Volatility Hearing Loss Cochlear Deafness Hearing Allergy Audition Hearing
Cochlear deafness
Because the blood supply to the cochlea is relatively fragile, it is easily damaged. All lesions in the cochlea can cause cochlear deafness. Usually, high frequency hearing is firstly damaged, and a valley-like hearing loss occurs. The typical audiogram is at 4000 Hz. The steep shape drop and the characteristics of the electrical audiometry test for cochlear hearing impairment are:
(1) Fu Cong phenomenon: The degree of hearing loss is reduced or disappeared due to the increased sound intensity of the stimulus; the strong sound tolerance is reduced, and the patient feels ear pain when the normal human's strong sound tolerance (105-110 dB) is not reached.
(2) Hearing: The sounds heard by the same tone patient are inconsistent, one high and one low.
(3) Pathological auditory adaptation: The hearing threshold is significantly increased during sustained sound stimulation.
2. Neurological deafness
Lesions that damage the cochlear nerve can cause neurological deafness. The clinical features are:
(1) High-frequency hearing is firstly damaged, gradually expanding to the mid-bass, and finally generally decreasing.
(2) The air conduction is larger than the bone conduction, but both are shortened.
(3) It has obvious pathological adaptation.
3. Central deafness
The lesion is located in the brainstem and brain, involving the cochlear nucleus and its central conduction pathway, and the central auditory cortex leads to central deafness.
(1) Brain-dry central deafness: involving the cochlear nucleus to produce one-sided deafness, to a lesser extent; if one side of the cochlear nucleus and the contralateral cross-fiber are involved, bilateral deafness is generated, with partial sexy deafness More common, common in the pons, medullary lesions.
(2) Cortical deafness: Cortical deafness is difficult to distinguish the nature of the sound, sometimes although the general hearing is not damaged, but the aesthetic ability of the language is reduced, because one side of the cochlear nerve fiber is projected to the bilateral auditory cortex, One side of the auditory cortex is damaged or one side of the conduction pathway is damaged resulting in one or both hearing loss.
Hearing impairment can lead to lifelong damage to a child's linguistic and verbal skills. The severity of the disorder is determined by several factors:
1 age at which hearing loss occurs;
2 the nature of hearing loss, ie its duration, the frequency of damage;
3 accurate assessment of hearing, ie the extent of loss;
4 The susceptibility of each child, including co-existing viral damage, mental retardation, and basic language defects.
For children with sensorineural hearing loss, the additional burden of conductive hearing loss can severely reduce their ability to discern speech. Hearing loss affects children with additional sensations, language and cognitive impairments, and is more serious than other healthy children. .
Common clinical symptoms of hearing impairment include tinnitus, hypersensitivity, deafness, auditory hallucinations, and hearing loss.
Examine
Hearing impairment examination
1. Cerebrospinal fluid examination.
2. Other necessary optional auxiliary examination items include blood routine, blood electrolytes, blood sugar, and urea nitrogen.
3. ENT examination and auditory examination.
4. Bottom of the skull, CT and MRI.
5. Other necessary optional auxiliary examination items include chest X-ray and ECG.
Diagnosis
Hearing impairment diagnosis
Diagnosis can be based on symptoms.
Differential diagnosis
1. Acoustic neuroma: Adults are more common, patients with slow onset, progressive hearing loss, sensorineural deafness, no recurrence; often have other symptoms of cranial nerve damage.
2. Brain stem lesions: vascular and tumor lesions of the brain stem, persistent vertigo symptoms, often nystagmus, hearing loss and other signs of the nervous system.
3. Cochlear nerve: drug toxic damage is more common in children, causing more damage to the cochlear nerve, but the degree and location of various drugs for cochlear nerve damage are not the same, some are biased in the cochlea, and some are biased in the vestibule. Or both.
Streptomycin sulfate, gentamicin mainly affects the vestibule; dihydrostreptomycin, neomycin, kanamycin, vancomycin affect the cochlea, of which neomycin affects the most severe cochlea, sulfa drugs can cause hearing Decreased and tinnitus, but if vestibular symptoms occur, hearing impairment will be difficult to recover; salicylic acid drugs can cause hearing loss in patients who are overdose or drug allergic, mainly degeneration of cochlear spiral ganglion cells, and the degree of damage is lighter. Easy to recover.
4. Common causes: diseases of conductive hearing impairment Most hearing defects are acquired conductive hearing loss, mostly related to otitis media and its sequelae. Almost all children have experienced mild to moderate edema caused by otitis media. Sexual or persistent hearing loss, recurrent or severe infection can lead to permanent defects, the most susceptible to otitis media are those with craniocerebral abnormalities (such as cleft palate), immunodeficiencies (such as infants with temporary hypogammaglobulinemia) and In children exposed to environmental risk factors such as swallowing, boys are more susceptible to otitis media than girls.
Cholesteatoma is a benign tumor that often occurs in untreated otitis media or congenital. Cholangioma can lead to necrosis and conductive hearing loss in the ossicular chain, infection and closure of the middle ear. It can lead to structural damage of the ossicle, and the long-term pathological process of the incus is the most common influencing factor, leading to significant conductive hearing loss.
