What Are the Most Common Causes of Deafness in Children?

Deafness can be divided into congenital deafness and acquired deafness according to the time when deafness occurs. Congenital deafness refers to deafness caused before or during birth. For example, most genetic deaf mothers have deafness in children caused by taking drugs during pregnancy and birth Deafness caused by hypoxia. Acquired deafness is deafness that occurs after a child suffers illness or injury after birth. According to the influence on language learning, pre-deaf deafness and post-deaf deafness can be divided into pre-deaf deafness. Pre-deaf deafness is a pre-deaf deafness that has appeared before language learning. The most commonly used classification method today is to classify it into conductive deafness, sensorineural hearing loss, and mixed hearing loss based on the site of the deafness.

Luo Renzhong

(Chief physician)

Department of Otolaryngology, Guangzhou Children's Hospital

Deafness is a general term for hearing impairment caused by organic or functional lesions of the auditory conduction pathway. Deafness is one of the most important issues affecting the quality of human life. Because infants and young children and children are the best period of hearing and speech development, if the deafness occurred during this period is not detected and treated in time, it will affect children's speech therapy development in different degrees. There are many types of deafness, and the most commonly used classification method is to divide them into conductive deafness, sensorineural deafness, and mixed deafness according to the location of the deafness.

Western Medicine Name: Deafness in children
Affiliated Department: Faculty-

Disease site: Ear
Main cause: Inflammation, genetic factors, etc.

Classification of deafness in children

Pediatric Deafness Conductive Deafness

Definition of Pediatric Deafness Conductive Deafness

Sound waves conducted through the air path are hindered by lesions in the external ear canal and middle ear, and the sound energy reaching the inner ear is weakened, causing people with hearing loss to varying degrees to be called conductive deafness.

Causes and treatment of deafness in children

Common causes of conductive deafness include inflammation: acute and chronic suppurative otitis media, acute and chronic secretory otitis media, and otitis media with adhesions. Trauma: Temporal bone fractures involve middle ear, tympanic trauma, and interruption of ossicular chain. Foreign body or other mechanical obstruction: foreign body in the external ear canal, iliac embolism, tumor, cholesteatoma, etc. Malformation: congenital atresia of external ear canal, malformation of ossicular chain, loss of tympanic membrane, vestibular window, dysplasia, etc. The following mainly introduces the most common secretory otitis media and suppurative otitis media in children.

Secretory otitis media is a non-purulent inflammation of the middle ear with tympanic effusion and hearing loss. The higher incidence of children is one of the common causes of hearing loss in children.

1. The main symptoms of clinical manifestations are hearing loss, ear pain, occlusion in the ear, and tinnitus. Most children do not have a complaint of hearing loss. Young children can show delayed speech development. Preschool children often show disregard for their parents' calls, and parents mistakenly think that their attention is not focused. School-age children have lower academic performance and require it when watching TV. Excessive volume is the main manifestation. If the child has only one ear and the other ear has normal hearing, it can be undetected for a long time and found during routine physical examination.

2. Diagnosis of tympanic membrane under otoscope. Congestion of the tympanic membrane in the acute phase is congested. Radially dilated vascular patterns are present around the tense region. When the tympanic fluid is accumulated, the tympanic membrane is yellowish or orange in color, the tympanic membrane movement is limited, and linear liquid planes or air bubbles are visible. The acoustic impedance map is of great value in the diagnosis of exudative otitis media. The flat type (type B) is the typical curve of this disease. The high negative pressure type (type C) indicates that the eustachian tube is dysfunctional, and the negative pressure of the tympanic cavity is greater than 200 daPa. According to the medical history and careful observation of the tympanic membrane, combined with the results of the acoustic impedance test, the diagnosis of exudative otitis media is generally not difficult. It is worth noting that because the mechanical-acoustic transmission mechanism of infants under the age of 1 is different from that of older children, children over 1 year of age use the standard 226 Hz detection tone, and children under 1 year of age use higher detection. Audio rate.

3. Treatment to clear middle ear effusion, improve middle ear ventilation and drainage-based treatment principles of the disease. Antibacterial drugs can be used for acute exudative otitis media. The application of diluted mucins is beneficial to the excretion function of cilia and promote the discharge of middle ear effusion. At the same time actively treat nasal diseases. For 3 months of ineffective drug treatment or recurrent secretory otitis media, surgical puncture can be performed and tympanic tube placement.

Suppurative otitis media is a purulent inflammation of the middle ear mucosa that occurs in children and is a common cause of hearing loss in children. Acute suppurative otitis media is a common infectious disease in childhood, with a high incidence, easy recurrence, and many complications and sequelae.

1. Clinical manifestations Infants and young children are not afraid to report their illness, often manifesting as ears of unknown origin, shaking their heads, and crying. Systemic symptoms are severe and fever is often accompanied by symptoms of gastrointestinal poisoning such as nausea, vomiting, and diarrhea. Because the scales of children under 2 years of age have not been closed, there is a rich vascular and lymphatic connection between the middle ear mucosa and the dura mater. Therefore, acute purulent inflammation of the middle ear can affect the adjacent dura mater and cause meningeal irritation.

2. Early diagnosis of otoscopy, congestion of tympanic membrane relaxation, radial expansion of blood vessels around the sacrum stem and tension. Following that, the tympanic membrane was diffusely congested, swollen, and bulged outward. The normal signs were difficult to identify, and small yellow spots were seen locally. If inflammation cannot be controlled in time, it develops into a tympanic membrane perforation. The perforation usually starts very small and is not easy to see. After thoroughly plotting the external ear, it is seen that there are pulsating highlights at the perforation, and pus is actually flowing from there. The tympanic membrane of the necrotic type quickly dissolves, forming a large perforation, palpation of the mastoid area of the ear may have slight tenderness, the tympanic sinus area is more obvious, and the hearing test is mostly conductive deaf. A few patients may have mixed hearing loss due to cochlear involvement Sensorineural hearing loss. The total number of white blood cells in the blood image increased, polymorphonuclear leukocytes increased, and the blood image became normal after the tympanic membrane was perforated.

3. Treatment to control infection, smooth drainage and removal of disease due to its treatment principles. Apply sufficient antibiotics or other antibacterial drugs to control the infection as soon as possible in order to completely cure the infection. Generally available drugs such as penicillins, cephalosporins. If early treatment is timely and appropriate, it can prevent perforation of the eardrum. After large-scale perforation, pus was taken for bacterial culture and drug sensitivity test. Refer to the results and use sensitive antibiotics instead. Antibiotics need to be used for about 10 days, pay attention to rest, and clear the stool. Those with severe systemic symptoms are given supportive therapy such as fluid replacement. In children, the tympanic membrane is thick and difficult to perforate. In order to prevent the infection from spreading into the skull, tympanostomy can be considered when necessary, and the drainage is shortened to shorten the course and prevent complications. If the mastoid airspace melts and pus is present, mastoidectomy should be performed in time.

Acute suppurative otitis media lasts more than 6 to 8 weeks, and the disease invades the middle ear mucosa, periosteum, or deep bone and causes irreversible damage, which is called chronic suppurative otitis media. Chronic suppurative otitis media in childhood often requires surgical treatment after the child's eustachian tube function improves. ^[1-3]

Sensorineural hearing loss in children with deafness

Definition of sensorineural hearing loss in children with deafness

Inner ear auditory hair cells, vascular veins, spiral ganglia, auditory nerves, or organic lesions in the auditory center can all hinder the perception and analysis of sound or affect the transmission of sound information. The hearing loss or hearing loss caused by this is called the sensory nerve Sexually deaf. Among them, those with hair cell lesions are called sensorineural hearing loss (cochlear deafness), and those with lesions in the auditory nerve and auditory pathways are called neurodeafness (post-cochlear hearing loss). Lesions that occur in the auditory central nucleus or the cerebral cortical auditory center are called central deafness.

Causes of sensorineural hearing loss in children with deafness

Hereditary factors are hearing impairments caused by developmental defects in the auditory organs secondary to genetic defects such as genetic or chromosomal abnormalities. Hereditary deafness does not always manifest as congenital deafness. Part of hereditary deafness is normal after birth. Hearing loss is only manifested at a certain age.

Non-hereditary congenital hearing loss refers to hearing impairment caused by maternal or childbirth factors during pregnancy. Viral infections, birth trauma and hyperbilirubinemia are the main causes. Mothers who suffer from syphilis, AIDS, or a large number of ototoxic drugs during pregnancy can also cause fetal deafness.

Non-hereditary acquired sensorineural hearing loss is more common in drug-induced hearing loss, sudden hearing loss, noise-induced hearing loss, viral or bacterial infection-related hearing loss, and systemic-related hearing loss.

Diagnosis and treatment of sensorineural hearing loss in children with deafness

Comprehensive and systematic collection of medical history, detailed ear and nose tests, rigorous hearing tests, and necessary imaging, laboratory and systemic laboratory diagnostic and differential diagnosis. For children with sensorineural hearing loss, early detection, early diagnosis and early intervention should be achieved. In recent years, newborn hearing screening has been widely carried out in China, and most regions have been able to detect and intervene in hearing-impaired children in a timely manner.

Cochlear hearing loss (sensory hearing loss)

Pure tone hearing thresholds show that air-bone conduction hearing decreases at the same time, air-bone conduction difference is less than 10dB, acoustic impedance test shows normal tympanum impedance map, ABR examination often shows that the amplitude of I wave decreases, and the latency of each wave increases with the increase of hearing loss. Very severely deaf ABR showed no response to maximum acoustic output. Because young children often cannot cooperate with pure tone hearing threshold examination, they often need to combine objective examination results such as ABR, acoustic impedance, 40HZ-related potential, and acoustic impedance (OAE). Treatment of cochlear hearing loss: Hearing aids can be selected. For children with cochlear hearing loss who have severe hearing loss in both ears, cochlear implantation is an effective treatment to improve hearing.

Post-snail deafness

Auditory neuropathy is a disease of auditory dysfunction caused by lesions in the auditory pathway (auditory nerve) located between the cochlea and the brainstem. It is characterized by auditory dysfunction and poor speech recognition ability, and the decrease in speech recognition rate is inconsistent with the decrease in hearing threshold level. The audiological examination is mainly characterized by normal OAE and abnormal or absent ABR. The prevalence of deaf children with auditory neuropathy as a high-risk factor is 11%. The typical diagnosis of auditory neuropathy is based on the disproportionately lower speech recognition rate than pure tone hearing, but it is difficult for infants and young children to obtain this basic and typical Separation phenomenon. The diagnosis of pediatric auditory neuropathy requires an audiological examination based on medical history and otological examination, including acoustic impedance, ABR, cochlear microphonic potential (CM), otoacoustic emission (OAE), and event-related potential (ERP), and Film degree exam. There are usually two treatments for pediatric auditory neuropathy: one is to provide patients with hearing aids, cochlear implants and other hearing aids; the other is to promote patient language learning, including auditory oral grammar and visual assisted speech grammar. However, the efficacy of this treatment is still controversial. ^[4-6]

Pediatric deafness mixed deafness

Definition of deafness in children

Middle ear and inner ear lesions coexist, and hearing impairment caused by sound wave transmission and feeling is called mixed deafness. Mixed deafness may be dominated by conductive deafness or sensorineural deafness, or it may exist in a form where conductive deafness and sensorineural deafness are roughly equivalent.