RU2481788C1 - Method of carrying out examination for assessment of auditory function in infants - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, namely to otolaryngology and audiology. Method lies in registration of short latency auditory evoked potentials (SLAEP) when as stimulus presented are wide-band audio clicks, transmitted through intra-ear telephone during natural or medicated sleep, with frequency of stimuli presentation 21/s, lower boundary of band of amplifier bandwidth 100 Hz, upper boundary 3000 Hz, analysis window 20 ms, number of averagings - 2000. Examination is performed in two stages. At the first stage registration of SLAEP is performed by increasing technique with successive double presentation of stimuli of each loudness - 20 dB, 40 dB, 60 dB, 80 dB, 90 dB, 103 dB. After that, at the second stage registration of SLAEP is performed when as stimulus presented is modulated in amplitude and frequency "chirp" signal with frequency 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz with the same parameters of stimulation. In addition at both stages of examination visualisation of V peak at minimal stimulus level is a criterion of SLAEP registration.

EFFECT: application of claimed invention makes it possible to increase objectivity and accuracy of diagnostics of auditory function in infants, to reduce examination time.

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Description

The invention relates to medicine, in particular to otorhinolaryngology and audiology, can be used in the examination of young children to identify and determine the degree of hearing loss, as well as the detection of deafness. The method allows for the early detection of hearing impairment in children of any age and objectively assess the degree of hearing loss, timely appoint appropriate therapy and electro-acoustic correction of hearing.

At the present stage, the possibilities of studying the auditory function of a newborn baby have expanded significantly - primarily due to the introduction of objective methods into clinical practice. Objective electrophysiological methods for determining auditory function remain the most important, and sometimes the only, option for examining hearing in children of the neonatal, infant and early childhood years, and are currently becoming more widespread in medical institutions. In clinical practice, short-latency auditory evoked potentials that record the potentials of the auditory nerve and acoustic structures of the brain stem are most in demand. The method of recording short-latency auditory evoked potentials of the brain stem is used to assess the degree of hearing loss in children.

For the prototype of the present invention, a method for evaluating auditory function according to the registration of short-latency auditory evoked potentials (VSWP) [Altman Ya.A. Guide to Audiology / Ya.A. Altman, G.A. Tavartkiladze. - M.: DMK Press, 2003. - 360 s]. The recording electrodes are located on the vertex or in the middle line of the forehead at the border of hair growth (positive), the active electrode (negative) is located on the mastoid process, and an additional ground electrode is located in the forehead. With the standard method of recording short-latency auditory evoked potential, the frequency of presentation of stimuli is from 11 to 21 / s. The lower limit of the amplifier passband is from 100 to 300 Hz, and the upper limit is from 2 to 3 kHz, the analysis window is 10-15 ms, and for newborns and children of the first year of life is 20 ms. Typically, 2000-4000 averages are used. In modern devices for registration of HWCs, there are various types of stimuli for registration (narrow and broadband clicks, tone signals, modulated stimuli). In most cases, the standard method for registering high-bandwidth click-through signals is used. As a stimulus for recording short-latency auditory evoked potentials, short acoustic clicks of variable polarity are used, but the use of very short tonal premises or filtered clicks is also possible. During testing, clicks or tones are heard through the headphones. To study auditory evoked potentials, head phones for audiometry (TDH-39 or HDA-280) or in-ear (insert phones) phones (ER-3A or ER-5A), which look like soft foam inserts, are used in the center of the insert, a sound guide passes through which signal is emitted (click or tone). The study is carried out during the sleep of the child.

Despite the undoubted advantages of the method taken as a prototype, the method has certain limitations. When registering CVS as a stimulus, broadband sound clicks are usually presented, which does not allow us to evaluate hearing thresholds at different frequencies, including in the low-frequency range (Levin S.V. Use of auditory evoked potentials in modern audiological research: Abstract of thesis ... cand. Medical science. - St. Petersburg, 2009. - 21 p .; Koroleva IV. Hearing impairment in young children: diagnosis and rehabilitation: a manual for doctors / I.V. Koroleva. - St. Petersburg, 2004 . - 78 C .; Chiappa, 1985). Although procedures have been developed for registering CWS for tonal bursts and band noise, they are not widely used. This is due to the fact that when using them, the examination time significantly increases, and the determined hearing thresholds at low frequencies can significantly differ from behavioral thresholds [Levin S.V. The use of auditory evoked potentials in modern audiological research: Abstract. dis. ... cand. honey. sciences. - St. Petersburg, 2009 .-- 21 p .; Chiappa, 1985; Purdy, Abbas, 2002].

In addition, when using head phones in small children, the problem of slipping the headphones when the child is horizontal and the size of the head of the child and the headband of the headphones does not match.

When using the in-ear phones, there are also problems of keeping them in the external auditory canal of the child, since there are no additional mounts on them and they easily slip out of the external auditory canal of children. In addition, the sound guide in the soft foam material of the earphones can be pinched or bent, which can lead to a weakening of the test signal that can affect the results of the study. The correct installation of the in-ear phones depends on the experience and qualifications of the doctor, and their incorrect installation can lead to the bend of the sound guide, the “stop” of the sound outlet in the wall of the external auditory canal and, ultimately, to insufficiently reliable research results.

This technique involves constant monitoring of the doctor during the entire study for the in-ear phones, which often requires correction of the installed phones when they slip out, which distracts the doctor from the study itself, can help awaken the child and increase the study time.

The objective of the invention was to develop a method for diagnosing the degree of hearing loss in young children with the determination of exact hearing thresholds in the low-frequency and high-frequency areas.

The technical result when using the invention is to increase the objectivity and accuracy of hearing diagnostics in young children, as well as reducing the examination time.

The specified technical result is achieved by the fact that in the method of conducting a study to assess auditory function in young children, which includes recording short-latency auditory evoked potentials (VSWR) when presented as an incentive, broadband sound clicks delivered through the earphone during natural or medical sleep, s frequency of stimulus presentation 21 / s, the lower limit of the amplifier passband 100 Hz, the upper limit of 3000 Hz, the analysis window - 20 ms, the number of averagings - 2000, s According to the invention, the study is carried out in two stages, and at the first stage, the registration of the VSWP is carried out according to an ascending method with successive twofold presentation of stimuli of each volume - 20 dB, 40 dB, 60 dB, 80 dB, 90 dB, 103 dB, after which they are carried out in the second stage registration of the VSWR upon presentation of a “chirp” signal with a frequency of 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz at the same stimulation parameters as a stimulus modulated in amplitude and frequency, while at both stages of the study, the criterion for recording the VSWR is visualization of the V peak with mini minimum stimulus level.

The invention is illustrated by the following figures: figure 1 shows casts of the external auditory canals of the child And .; figure 2 - individually made insert from varioflex; figure 3 - modulated in amplitude and frequency "chirp" signal; figure 4 - frequency-specific signal, modulated in amplitude and frequency (chirp), the window of stimulation parameters (device Neuro-Audio, Neurosoft); figure 5 - the amplitude of the V peak of the VSWR when stimulated by a click (A) and a frequency-specific "chirp" signal (B); in Fig.6 - well-visualized V peak at a stimulus volume of 60 dB (A), difficult to visualize V peak at a stimulus volume of 40 dB (B); Fig.7 is a well-visualized V peak when stimulated by "chirp" stimulus at a frequency of 2000 Hz at a volume of 40 dB.

The proposed method is as follows.

The recording electrodes are arranged in a standard way: positive - on the midline of the forehead, on the border of hair growth, negative ones on the mastoid processes, a ground electrode is placed in the forehead. The study is carried out during the natural or medical sleep of the child.

Instead of the traditionally used headphone or earphone, phones with individually manufactured earphone earbuds are used. For their manufacture, a certified and approved medical impression mass is used. Using a syringe and a two-component impression mass, casts of the external auditory canals of the right and left ears of the child are made (Fig. 1), according to which individual earmolds are made of a special material - varioflex (Fig. 2). This material is certified, specially designed for the manufacture of individual ear buds for hearing aids. These earbuds exactly correspond to the dimensions of the external auditory canals of the child, are firmly held in the ear, do not slip out of the ear during the examination and do not require constant monitoring by the doctor. In addition, the sound guide, which is located inside the insert, is reliably protected from excesses, and the shape of the insert itself contributes to the correct installation of the sound guide, which completely eliminates the influence of the doctor’s qualifications and the method of installing telephones on the examination results.

The study is carried out in 2 stages. At both stages of the operation, the criterion for registration of the VSWP is the visualization of the V peak with a minimum level of stimulus.

Stage 1: The study is carried out using broadband clicks according to an ascending method with standardly used stimulation parameters: stimulus presentation frequency 21 / s, amplifier bandwidth lower limit - 100 Hz, upper limit - 3000 kHz, analysis window - 20 ms, averaging amount - 2000 During testing, the test signals are sent through telephones with individual inserts after preliminary calibration. First, one ear is tested, then the other, the presentation of stimuli begins with quieter sounds with a subsequent increase - 20 dB, 40 dB, 60 dB, 80 dB, 90 dB, 103 dB. Each volume is presented twice to exclude artifacts. Registration criterion: visualization of the V peak at the minimum stimulus level. The upward method allows preserving the child’s sleep, since the presentation of initially loud stimuli (possibly heard by the child) in some children contributes to the awakening and termination of the study. Thresholds for visualization of HEPC when examined by broadband sound clicks correspond to hearing thresholds in the range of 2-4 kHz, which coincides with published data [Altman Ya.A. Guide to Audiology / Ya.A. Altman, G.A. Tavartkiladze. - M .: DMK Press, 2003. - 360 p .; Levin S.V. The use of auditory evoked potentials in modern audiological research: Abstract. dis. ... cand. honey. sciences. - St. Petersburg, 2009. - 21 p.].

Stage 2: The study is carried out using a special stimulus, modulated in amplitude and frequency - “chirp” signal (figure 3). As a stimulus, use frequency-specific modulated chirp signals with a frequency of: 500 Hz; 1000 Hz; 2000 Hz and 4000 Hz (figure 4). The remaining stimulation parameters do not change: the frequency of presentation of stimuli is 21 / s, the lower limit of the amplifier bandwidth is 100 Hz, the upper limit is 3000 kHz, and the analysis window is 20 ms. The second stage of the study is necessary, since at the first stage of the study, visualization and detection of the V peak is a difficult task for the researcher due to the fact that with a decrease in the volume of the stimulus, the amplitude of the V peak decreases. In the presence of a low-amplitude peak on the recorded curve, the question arises before the researcher: is this small peak the fifth or is it an artifact (Fig.6).

Using the second stage of the study using special “chirp” stimuli, one can check the correctness of the interpretation of the hearing threshold, namely: if the low-amplitude peak is the fifth, then when measured with “chirp” stimuli at a frequency of 2000 Hz and 4000 Hz with stimulation at the same level volume, get a well-visualized high-amplitude V peak (since the amplitude of the peaks obtained when applying "chirp" stimuli is higher than when using a broadband click).

The comparison is carried out at 2000 and 4000 Hz due to the fact that the thresholds of visualization of the VSWR in the study with a broadband sound click corresponds to hearing thresholds in the range of 2-4 kHz. Other frequencies (500 and 1000 Hz) when used with chirp stimuli are used to refine hearing thresholds at low frequencies.

Thus, the second stage complements the first, with the help of it the researcher clarifies the hearing thresholds obtained during the first stage. The appearance of a high-amplitude V peak in the second stage allows the researcher to verify the hearing thresholds obtained in the first stage, and can also reduce the study time, since even a small number of accumulations (800) allows you to see the high-amplitude V peak (Figs. 5-7).

The advantages of the proposed method, compared with the known, the following:

- increasing the information content, objectivity and accuracy of diagnosis of reduced auditory function of the child at various frequencies;

- an increase in diagnostic capabilities for the timely identification of children with a high risk of hearing loss;

- reducing the time of examination of the child;

- eliminates errors and artifacts associated with improper installation of phones in the child’s ear.

The invention is illustrated by the following clinical examples.

Example 1

Child I., 2 years 3 months, medical history No. 10685.

Parents complain about the underdevelopment of speech, the lack of reaction of the child to quiet sounds and sounds of the speech range.

Anamnesis of life: Birth weight - 1500 g, congenital pneumonia, moderate hypoxic hemorrhagic damage to the central nervous system, prematurity 3 degrees, bronchopulmonary dysplasia, early anemia of premature infants, the use of gentamicin for 6 days. Heredity - not burdened.

Anamnesis of the disease: from 8 months, parents began to notice that the child does not respond well to speech addressed to him, by 2 years old - he pronounces separate phrases “ma”, “ba”, does not understand the speech addressed to him, the parents associated the lack of reaction to sounds with neurological status, and therefore turned to an otorhinolaryngologist in 2 years 3 months.

ENT status: ENT organs without visible visual changes.

Otoscopy - eardrum gray, contour.

Impedanceometry:

AD - tympanogram-type "A", p -32daPa, reflexes are not recorded;

AS - tympanogram-type "A", p -26daPa, reflexes are recorded at low frequencies.

TE UAE and DP grams are not recorded.

Test with a sign teacher: unconditionally indicative reaction: a drum - 4 meters, a pipe - 1.5 meters, an accordion - 0.1 meters, there is no answer to other non-speech and speech stimuli.

An electrophysiological study of hearing using this technique was performed in a state of natural sleep on a Neuro-Audio device (Neurosoft, Russia).

The results are:

The thresholds for the appearance of VSWR on a broadband click are 100 dB on the right and 90 dB on the left. The thresholds for the occurrence of VSWR on frequency-specific modulated “chirp” stimuli (500 Hz; 1000 Hz; 2000 Hz and 4000 Hz): on the right - 80 dB, 90 dB, 80 dB, 100 dB; 60 dB, 70 dB, 60 dB, 80 dB on the left.

Based on the survey DS: Bilateral sensorineural hearing loss, right IV degree, left III degree.

The obtained hearing thresholds were used later in the selection and tuning of digital programmable hearing aids, fine-tuning was carried out with the participation of an audio teacher. As a result of electro-acoustic correction of hearing, the child began to respond to all sounds of the non-speech and speech range from a distance of 6 meters, as a result of correctional and pedagogical work after 6 months the child began to speak the first monosyllabic words, and after 8 months - bisyllabic and polysyllabic words.

At 2 years 11 months, the child developed a conditional-motor reaction to sounds, performed game tonal threshold audiometry, hearing thresholds at the main speech frequencies (500 Hz; 1000 Hz; 2000 Hz and 4000 Hz): on the right - 80 dB; 85 dB 90 dB 85 dB 65 dB on the left; 70 dB; 65 dB 70 dB Thus, the sensorineural hearing loss of the fourth degree on the right and the third degree on the left was observed in the child, which coincided with the data of an electrophysiological study of hearing. Thus, the use of this method of evaluating auditory function has made it possible to accurately diagnose hearing thresholds of a child and begin rehabilitation and correctional pedagogical work.

Example 2

Baby A., 2.5 months, outpatient card No. 10264.

Anamnesis of life: Birth weight - 2300 g, congenital hydrocephalus, prematurity 1 tbsp.

Medical history: A delayed evoked otoacoustic emission (TE OAE) was recorded in the maternity hospital, TE OAE was not registered binaurally, due to the lack of registration of otoacoustic emission with suspected hearing loss, the child was sent for in-depth audiological examination.

ENT status: ENT organs: nose - the mucous membrane is hyperemic, swollen, in the nasal passages - mucopurulent secretion, pink pharynx,

Otoscopy - eardrum - stiff, poorly contoured.

Impedanceometry:

AD - tympanogram-type "B", p -214 daPa, reflexes are not recorded;

AS - tympanogram-type "B", p -198 daPa, reflexes are not recorded.

TE UAE and DP grams are not recorded.

An electrophysiological study of hearing using this technique was performed in a state of natural sleep on a Neuro-Audio device (Neurosoft, Russia).

The results are:

The thresholds for the appearance of VSWR on a broadband click are 40 dB on the right and 30 dB on the left. The thresholds for the occurrence of VSWR on frequency-specific modulated “chirp” stimuli (500 Hz; 1000 Hz; 2000 Hz and 4000 Hz): on the right - 30 dB, 40 dB, 40 dB, 30 dB; left - 40 dB, 50 dB, 40 dB, 30 dB.

Based on the survey DS: Purulent rhinitis. Bilateral exudative otitis media. Conducted hearing loss of the I degree.

Purulent rhinitis and bilateral exudative otitis media were treated according to the standard method, then 3 weeks after treatment, the impedance measurements were normal. In a repeated electrophysiological study of the child, the thresholds for the appearance of VSWR on a broadband click and frequency-specific stimuli did not exceed 20 dB, and therefore the suspicion of the presence of sensorineural hearing loss was removed. When re-registering at 6 months, delayed evoked otoacoustic emission was recorded binaurally, and the child's speech development did not lag behind peers, which confirmed the data of electrophysiological testing of the child.

Thus, the application of the developed method for hearing assessment allows you to more accurately diagnose the degree of hearing loss in children who do not perform tonal threshold audiometry. Further treatment and rehabilitation is carried out in accordance with the diagnosed degree of hearing loss. Assessment of the child’s hearing thresholds made it possible to start treatment and correctional measures in a timely manner, which is important for the child’s speech and psychoemotional development.

Claims (2)

1. A method of conducting a study to assess auditory function in young children, including recording short-latency auditory evoked potentials (VSWR) upon presentation as a stimulus of broadband sound clicks delivered through the intercom phone during natural or drug sleep, with a stimulus presentation frequency of 21 / s , the lower limit of the amplifier passband 100 Hz, the upper limit of 3000 Hz, the analysis window of 20 ms, the number of averagings of 2000, characterized in that the study is carried out in two stages, with than at the first stage, the registration of the VSWP is carried out according to the ascending method with successive twofold presentation of stimuli of each volume of 20 dB, 40 dB, 60 dB, 80 dB, 90 dB, 103 dB, after which at the second stage the registration of the VSWP is presented upon presentation as a stimulus modulated by the amplitude and frequency - “chirp” of the signal with a frequency of 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz with the same stimulation parameters, and at both stages of the study, the criterion for recording the VSWR is visualization of the V peak with a minimum stimulus level. 2. The method according to claim 1, characterized in that they use telephones with individually made intra-ear hearing aids.

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