Dpoae-what isDpoae-dpoaeWhat do you mea
Early hearing impairment has a serious impact on the language, intelligence and mental development of infants and young children. According to the survey, China has2057 Ten thousand people with hearing disabilities, among them7 Children under the age of80 Million. In order to detect congenital deafness early and early intervention to reduce the incidence of children with disabilities, the Ministry of Health has included newborn hearing screening into routine screening programs. Newborn hearing screening is a rapid and simple test method or means for detecting large groups of newborns, while distortion product otoacoustic emissions (Distortion product otoacoustic emission ,DPOAEThe test method is one of the main tests for hearing screening of newborns.
1. DPOAESounding mechanism
We know that an important function of the cochlea is to recognize the sound of the outside world. but DT Kemp O1978In an experiment in the year, it was found that in addition to distinguishing sounds, the cochlea can also create sounds, that is, additional sound energy is generated in the cochlea, which is transmitted backwards from the inner ear to the outer ear and can be measured in the external auditory canal. Such a phenomenon is calledOtoacoustic emissions(OAE).OAEIt is the energy generated by the cochlear sensory cells in response to acoustic stimulation. The sound of the tympanic membrane is caused by the ovate window pushing the ossicular chain and is recorded by the external auditory canal microelectrode.. Distortion product otoacoustic emission (DPOAE) refers to a pure tone that has a certain intensity ratio relationship, which stimulates the audio energy generated by the cochlea, which can be recorded in the external auditory canal and has frequency and stimulation frequency.. It is used to evaluate the function of the auditory peripheral system, especially the function of the outer hair cells of the cochlea, while the inner hair cells rarely respond.
The picture below shows the arrangement of the cochlear hair cells. The upper line is the inner hair cells, and the lower three lines are classic.V“The outer hair cells of the font:
2,DPOAEDivided into screening type and diagnostic type
Screening typeDPOAEAs a newborn hearing screening tool, it has the characteristics of objectivity, sensitivity, rapid and non-invasive, low environmental requirements, and simple operation.. It mainly measures the pass rate and judges the pass.DPOAEThe indicator is: each frequency otoacoustic emission response point is higher thaPASS/REFER(Pass / referral)line,4The amplitude of each frequency is normal, and the noise intensity of each test frequency is lower than the corresponding otoacoustic emission response point.10 dB. However, because it is only a screening type, there are also drawbacks, that is, it cannot reflect the details of the inspection, so there is a diagnostic type.DPOAE.
To confirm the hearing loss of newborns, in addition to usingABRSometimes also using diagnostic typeDPOAE. Because this time screening typeDPOAEIt is not possible to explain the hearing loss of children very well and in great detail. DiagnosticDPOAEWhat is reflected at this time is not only the passing rate of several frequencies, but the hearing situation of each frequency; not only the normal value of the amplitude, but the specific value of each frequency. Although the reaction mechanism of the two is almost the same, the reaction is much more detailed. However, due toDPOAEThe accuracy rate itself is already high, and the diagnostic typeDPOAEIt takes a long time and the results are complicated, so there is little diagnostic type.DPOAENeed.
just becauseDPOAEThe sensitivity is high, so it can be used for early diagnosis of many hearing diseases such as hereditary sensorineural hearing loss, sudden deafness, tinnitus, Meniere’s disease, and acoustic neuroma. In addition,DPOAEIt is also possible to monitor some risk factors that may cause hearing damage, such as: monitoring of noise sputum, monitoring of ototoxic drugs, etc., and the otoacoustic emissions can detect potential abnormalities before hearing abnormalities have occurred. The application of newborn hearing screening is self-evident, in general,DPOAEThe response amplitude and detection rate will decrease with age, and the response rate of infants and young children is significantly higher than that of adults. And the frequency is large, the amplitude is large, and the detection rate is high.
4,DPOAEApplication in newborn screening
Hearing disorder is concealed in infancy, and it is often difficult for parents to detect it. When the language disorder occurs in childhood, it will cause parents to pay attention. At this time, the diagnosis is already late, and the best treatment opportunity is lost, thus delaying the child’s Language development. After the baby is bor6Month~1Years of age are the most critical period of language development. If hearing impairment is not diagnosed and treated in time, it will mean that the key moments of language learning will be lost, resulting in impaired intellectual and emotional development of children, affecting their quality of life and social interaction. Capacity will also put a heavy burden on society and families. Therefore, how to detect children with hearing impairment early is of great significance. andDPOAEIt is exactly what can help us “early discovery”, “early treatment” for children, and let parents participate in “early intervention” so that children can be “deaf and dumb”.
5,DPOAEFalse positive and false negative
As mentioned in the previous sounding mechanism,OAEMainly reflects the function of the outer hair cells of the cochleaIt can not reflect the hair cells in the cochlea and the auditory pathway after the cochlea. Therefore, this method may lead to missed diagnosis or misdiagnosis, especially hearing impairment caused by central nervous system diseases, including auditory neuropathy. therefore,DPOAEPass or fail does not fully reflect the overall state of hearing.
If passedDPOAE Testing, through screening, but this does not necessarily mean that it is really okay, its false negatives may be related to the following factors:
a. Screening hearing If the average hearing loss is less tha30Decibel cannot be screened out
b. Screening techniques used by hospitals and other institutions are not able to check all frequencies, and newborns have separate low frequencies (<1khz) or high frequency hearing loss (>2khzWhen it is possible, it may not be detected
c.Some hearing disorders (such as auditory neuropathy) but useOAECan not be checked, there may be false negatives
d. 20%-30%Hearing loss in infants and young children is late, progressive or volatility
In newborn screening, the problem caused by false negatives is that some hearing-impaired people lose the opportunity of early diagnosis and early treatment.
In newborn screening, the problem caused by false negatives is that some hearing-impaired people lose the opportunity of early diagnosis and early treatment..
Correspondingly, sometimes it does not pass, but this does not necessarily mean something. Parents should not worry too much. They should analyze it comprehensively. It may have false positives because of the following factors:
a.Initial examination age Studies have found that after birth24Hearing screening for hours, the highest incidence of “false positives”, so infants and toddlers who are born naturally48Test after hours or test one day before discharge, try to avoid after birth24Hour screening
b.Neonatal dysplasia Hearing transmission and nervous system development may be immature in premature and low birth weight children. Hearing screening during hospitalization is temporary, and with the development of various organs of the body,42Do it again during the day of reviewDPOAESignificantly improved pass rate
c.External or middle ear Neonatal ear canal and middle ear cavity may have amniotic fluid, fetal residue
d.Child’s status When you are screening, you should be quiet or sleep, relax your body.
False positive problems:
1)The object returns the cost of the inspection;
2)The mental burden of the subject’s parents;
3)Unnecessary treatment costs;4)The high false positive rate increases the referral rate and the difficulty of follow-up, and the probability of loss of hearing loss increases.
7,to sum up
In summary, DPOAEAs a means of hearing screening, the well-being of the deaf is also incalculable. Because of it, we can really achieve “early discovery”, thus achieving “early treatment” and “early intervention.” AndDPOAEIt will also continue to improve with the development of society, and gradually become accepted and familiar to people.