Method for determining likelihood of cognitive impairment in patients

Abstract

FIELD: physiology; audiology; otolaryngology.SUBSTANCE: used to determine the likelihood of cognitive pathology in patients. At the same time, steady-state auditory evoked potentials are recorded for each ear at a modulation frequency of 90 Hz at carrier frequencies of 500, 1000, 2000, and 4000 Hz at a stimulus intensity of 50 dB. Registration of stationary auditory evoked potentials at a modulation frequency of 40 Hz. A comparison is made of the hearing thresholds recorded at two modulation frequencies of 40 and 90 Hz at each of the carrier frequencies of 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz. If the difference between hearing thresholds at all carrier frequencies does not exceed 5 dB, then the patient is referred for consultation to specialized specialists to assess their cognitive status.EFFECT: expansion of means and methods for identifying cognitive pathology in patients and the minimization of the influence of subjective factors during identification.4 cl, 8 tbl, 2 ex

Description

[0001] Technical field

[0002] The invention relates to medicine, physiology, surdology-otolaryngology, pediatrics, neurology and can be used to identify cognitive pathology in patients.

[0003] Technology Level

[0004] Auditory Steady State Responses (ASSRs) are an objective hearing test that records the brain's electrophysiological response to frequency-specific modulated sound signals. This test is used when pure-tone threshold audiometry is impossible, such as in young children or individuals with cognitive or physical impairments. Depending on the modulation frequency, ASSRs are recorded from different parts of the brain: at a stimulus presentation frequency of 70-110 Hz, ASSRs are generated by brainstem structures, while at 35-45 Hz, they are of cortical origin.

[0005] Differences in the recording thresholds of electrophysiological responses to acoustic stimulation from the central and peripheral areas of the auditory system may be related to temporal integration, which is itself a central phenomenon. These differences are associated with the central processing of the received signals from the transformed acoustic stimulation.

[0006] Comparing both central and peripheral neural response parameters in a subject can be informative, as it allows one to determine whether sound perception problems reflect limitations in the auditory periphery or at more central levels of the auditory system. Such information can influence decisions regarding treatment or rehabilitation tactics. Scheperle and Abbas [1] studied the relationship between peripheral and central areas of the auditory analyzer to predict psychophysical tasks, as well as speech perception. Furthermore, a number of studies confirm that in people with cognitive impairment, hearing thresholds at a stimulus frequency of 40 Hz do not differ significantly from thresholds recorded at a modulation frequency of 80 Hz, which may be a marker of cognitive pathology [2].

[0007] Children with cognitive impairments often have a complicated perinatal history, including prematurity, low birth weight, severe perinatal CNS damage, and neonatal intensive care unit stays of more than 48 hours. These medical histories are risk factors for hearing loss and deafness, and their presence warrants a comprehensive audiological examination to detect or rule out hearing pathology. Furthermore, this category of patients often experiences speech development delays, which also requires a comprehensive audiological examination, which includes recording steady-state auditory potentials at a modulation frequency of 90 Hz to determine hearing thresholds at carrier frequencies of 500, 1000, 2000, and 4000 Hertz (Hz).Additional recording of steady-state auditory potentials at a modulating frequency of 40 Hz and comparison of the obtained hearing thresholds with the thresholds recorded at a frequency of 90 Hz can help a specialist identify the presence of cognitive pathology in a patient.

[0008] Currently, cognitive impairment is diagnosed using experimental psychological, neuropsychological, and computerized methods [3,4]. A popular and widely used method for determining the level of intellectual development is the Wechsler Intelligence Scale for Children (WISC) and its version adapted to the conditions of our country [5]. It is designed to assess the cognitive status of children aged 5 years and older, which can affect the quality of medical care, since early detection of pathology contributes to increased effectiveness of rehabilitation. Until the age of 3-4 years, the child is examined using fixed observation in natural or experimentally simulated situations [4]. This method, in turn, is not objective enough.

[0009] A method for diagnosing autism spectrum disorders in patients is known in the prior art (RU2836018C1, March 10, 2025). A disadvantage of this method is the need for a specialist to interpret the test results, as the IV peaks are assigned by the physician conducting the test when recording short-latency auditory evoked potentials (SLAEPs). The recording of steady-state auditory evoked potentials is fully automated, and the test results are generated using an algorithm employing Fourier analysis, eliminating human error. Another disadvantage is its dependence on the patient's age: this method is unable to diagnose pathology in children under one year of age, as certain areas of the brain are not fully developed before this age, and the obtained data may be biased.The ASSR recording method, in turn, is used from birth, as the algorithm built into the device has no age restrictions. This method is the closest, so it was chosen as the prototype.

[0010] In order to expand the means and methods for diagnosing cognitive impairment in patients, the authors proposed a method that does not depend on the patient’s age and the subjective opinion of the specialist.

[0011] Disclosure of the essence of the invention

[0012] The technical task is to develop a method for identifying cognitive impairments based on the recording of stationary auditory potentials.

[0013] The technical result is the expansion of means and methods for diagnosing (detecting) cognitive pathology in patients, helping to minimize the influence of subjective factors during diagnosis (detection).

[0014] The technical result of the claimed method is achieved by recording stationary auditory potentials at modulating frequencies of 40 and 90 Hz and subsequently comparing the hearing thresholds at these frequencies.

[0015] A method for diagnosing cognitive pathology in patients, characterized by the fact that at each carrier frequency, sequentially, starting with a modulating frequency of 90 Hz:

[0016] A) Two electrodes are attached to the scalp of a sleeping patient in the vertex area or along the midline of the forehead and one electrode above the right and left mammillary processes;

[0017] B) Electronic wires from a device for recording short-latency auditory evoked potentials (ALEP) and ASSR are connected to the electrodes;

[0018] B) The interelectrode resistance is checked, after which an acoustic signal is sent through in-ear headphones located in each external auditory canal, or headphones that are applied to each auricle;

[0019] G) after this, stationary auditory evoked potentials are recorded simultaneously for each ear at carrier frequencies of 500, 1000, 2000 and 4000 Hz at a stimulus intensity of 50 dB;

[0020] D) when recording a response to a stimulus of a given intensity, it is reduced in 10 dB increments until the response ceases to be recorded, and then increased in 5 dB increments;

[0021] E) in this case, if the response to a stimulus with an intensity of 50 dB is not recorded, then it is increased in 10 dB increments and when recording a response, it is decreased in 5 dB increments;

[0022] After the diagnosis at stages A-E, if cognitive pathology is suspected in the patient, stationary auditory evoked potentials are recorded at a modulation frequency of 40 Hz, then a comparison is made of the hearing thresholds recorded at two modulation frequencies of 40 and 90 Hz on each of the carrier frequencies of 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz,

[0023] If the difference between the hearing thresholds at all carrier frequencies does not exceed 5 dB, then the patient is referred for consultation to specialized specialists to assess the cognitive status.

[0024] A method further characterized by the fact that at stage A two electrodes are fixed in the vertex region, one of them positive, and the second of them reference.

[0025] A method further characterized by the fact that at stage A, negative electrodes are fixed over the right and left mammillary processes.

[0026] A method further characterized in that a modulating frequency of 90 Hz is used as a standard component of an extended audiological examination.

[0027] A method further characterized by the fact that at stage B the interelectrode resistance should be no more than 5 kOhm.

[0028] Terms and definitions used in describing the claimed method:

[0029] Auditory Steady State Responses (ASSR) is an objective method of hearing research that records the electrophysiological response of the brain to frequency-specific modulated sound signals [6].

[0030] Carrier frequency is the frequency of the stimulus to which a response occurs in the hair cells in the tonotopically characteristic areas of the cochlea for a given frequency. [6].

[0031] Modulation frequency is the frequency at which the stimulus is applied [6].

[0032] Acoustic stimulation - delivery of sounds (frequency-specific modulated sound signals) through in-ear headphones (earphones) [7].

[0033] In-ear headphones are soft foam earbuds with a sound guide running through the center through which an acoustic stimulus is delivered.[7].

[0034] The electrode is a rectangular plate completely covered with gel and connected to an alligator clip. The electrode is applied to the patient's skin to establish a connection between the body surface and the electronic wire of the ASSR recording device [7].

[0035] Implementation of the invention

[0036] Depending on the modulation frequency, steady-state auditory potentials are recorded from different parts of the brain: at a stimulus presentation frequency in the range of 70-110 Hz, ASSRs are generated by brainstem structures, and at a frequency of 35-45 Hz, ASSRs are of cortical origin. Shahmiri et al. [2] found that in people without cognitive pathology, the differences between ASSR thresholds at modulating frequencies of 40 and 80 Hz were more than 5 dB HL at all studied carrier frequencies, whereas in patients with cognitive impairment, the thresholds differed by less than 5 dB.

[0037] The claimed method is carried out as follows. Four electrodes are attached to the patient's scalp: two electrodes (positive and reference) in the vertex area or along the midline of the forehead, and one (negative) electrode above the right and left mastoid processes. The skin is first degreased with alcohol and treated with an abrasive paste, then the electrodes are firmly attached to the skin. The patient is placed on a couch, and electronic wires from the ABR and ASSR recording device are connected to the electrodes. After installing the electrodes, the interelectrode resistance is checked, which should be no more than 5 kOhm, since higher resistance may result in unreliable examination results. [8] During the examination, the patient should be in a state of natural or drug-induced sleep, since their movements distort the recorded results.Next, earphones are inserted into the right and left external auditory canals, through which an acoustic stimulus—frequency-specific modulated sound signals—is delivered. Headphones placed against each auricle can also be used. Steady-state auditory potentials are recorded using the Eclipse device, manufactured by Interacustics. Auditory responses of the brain are recorded simultaneously to constant modulated tones at frequencies of 500, 1000, 2000, and 4000 Hz at a stimulus intensity of 50 decibels (dB). Then, while recording the response to a stimulus of this intensity, the intensity is decreased in 10 dB increments until the response is no longer recorded, and then increased in 5 dB increments. If a response to a stimulus of 50 dB intensity is not recorded, the intensity is increased in 10 dB increments, and while recording the response, the intensity is decreased in 5 dB increments.This algorithm is reproduced at each carrier frequency, and the resulting value serves as the threshold for recording steady-state auditory potentials. The study is initially conducted using a modulating frequency of 90 Hz, a standard component of an extensive audiological examination. Then, if cognitive impairment is suspected in a patient, steady-state auditory evoked potentials are recorded at a modulation frequency of 40 Hz.

[0038] Next, a comparison is made between the hearing thresholds recorded at two modulation frequencies (40 and 90 Hz) at each carrier frequency (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz). If the difference between the hearing thresholds at all carrier frequencies does not exceed 5 dB, the patient should be suspected of having cognitive pathology and referred to specialized specialists for an assessment of their cognitive status.

[0039] The possibility of implementing the claimed invention is disclosed in the following examples.

[0040] Example 1. Patient without cognitive impairment

[0041] A 9-month-old child underwent a comprehensive audiological examination due to risk factors for hearing loss (acute neonatal asphyxia, 5-day stay in the intensive care unit, neonatal jaundice, and congenital cytomegalovirus infection). According to the parents, the child passed the audiological screening at the maternity hospital. Early motor development: the child rocked and held his head from 7 months, and rolled onto his side from 8 months. Early speech development: cooing from 5 months; at the time of examination, speech was represented by unrelated babbling.

[0042] Four electrodes were attached to the patient's scalp: two electrodes (positive and reference) in the vertex (or along the midline of the forehead), and one (negative) electrode each above the right and left mammillary processes. The skin was first degreased with alcohol and treated with an abrasive paste, then the electrodes were firmly attached to the skin. The patient was positioned on a couch, and electronic wires from the ABR and ASSR recording device were connected to the electrodes. After placement of the electrodes, the interelectrode resistance was checked, which was 4 kOhm. The patient was in a state of natural sleep during the examination. Next, earphones were placed in the right and left external auditory canals, through which an acoustic stimulus (frequency-specific modulated sound signals) was delivered. The recording of steady-state auditory potentials was carried out using the Eclipse device, manufactured by Interacustics.First, ABR recordings were performed to assess auditory function. The V peak was recorded at a stimulus intensity (click) of 20 dB nHL. Then, steady-state auditory evoked potentials were recorded simultaneously at frequencies of 500, 1000, 2000, and 4000 Hz at a stimulus intensity of 50 decibels (dB). Then, when recording a response to a stimulus of a given intensity, it was decreased in 10 dB increments until the response was no longer recorded, and then increased in 5 dB increments. If no response to a stimulus with an intensity of 50 dB was recorded, it was increased in 10 dB increments and decreased in 5 dB increments when recording a response. This algorithm was reproduced at each of the carrier frequencies, thus recording hearing thresholds at a modulation frequency of 90 Hz, which are presented in Tables 1 and 2.

[0043]

[0044] Then, steady-state auditory evoked potentials were recorded at a modulation frequency of 40 Hz to assess the child's risk of cognitive impairment due to a complicated perinatal history and motor developmental delay. The hearing thresholds recorded at a modulation frequency of 40 Hz are presented in Tables 3 and 4.

[0045]

[0046] Next, we compared the hearing thresholds recorded at two modulation frequencies (40 and 90 Hz) at each of the carrier frequencies (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz). In this example, the difference between the hearing thresholds at all carrier frequencies (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz) was more than 5 dB.

[0047] Conclusion. The use of the proposed method did not reveal any cognitive pathology in the patient. The patient was advised to monitor the child's psychoverbal development and, if any complaints are present, refer the child to a specialist.

[0048] Example 2. Patient with cognitive impairment

[0049] A 1 year 7 month old child underwent an extensive audiological examination due to complaints of speech delay. According to the mother, the child's medical history includes prematurity at 34 weeks, weight at resuscitation of 2200 g, and a 6-day stay in the intensive care unit. According to the parents, the child passed an audiological screening at the maternity hospital. Early motor development: head support since 4 months, rollover since 8 months, and belly crawling since 10 months. Early speech development: cooing since 6 months, speech not developed at the time of examination, consisting of unrelated babble, and no words in the vocabulary.

[0050] Four electrodes were attached to the patient's scalp: two electrodes (positive and reference) in the vertex (or along the midline of the forehead), and one (negative) electrode each above the right and left mammillary processes. The skin was first degreased with alcohol and treated with an abrasive paste, then the electrodes were firmly attached to the skin. The patient was positioned on a couch, and electronic wires from the ABR and ASSR recording device were connected to the electrodes. After placement of the electrodes, the interelectrode resistance was checked, which was 3 kOhm. The patient was in a state of natural sleep during the examination. Next, earphones were placed in the right and left external auditory canals, through which an acoustic stimulus (frequency-specific modulated sound signals) was delivered. The recording of steady-state auditory potentials was carried out using the Eclipse device, manufactured by Interacustics.First, ABR recordings were performed to assess auditory function. The V peak was recorded at a stimulus intensity (click) of 20 dB nHL. Then, steady-state auditory evoked potentials were recorded simultaneously at frequencies of 500, 1000, 2000, and 4000 Hz at a stimulus intensity of 50 decibels (dB). Then, when recording a response to a stimulus of a given intensity, it was decreased in 10 dB increments until the response was no longer recorded, and then increased in 5 dB increments. If no response to a stimulus with an intensity of 50 dB was recorded, it was increased in 10 dB increments and decreased in 5 dB increments when recording a response. This algorithm was reproduced at each of the carrier frequencies, thus recording hearing thresholds at a modulation frequency of 90 Hz, which are presented in Tables 5 and 6.

[0051]

[0052] Then, steady-state auditory evoked potentials were recorded at a modulation frequency of 40 Hz to assess the child's risk of cognitive impairment due to a complicated perinatal history and delayed motor and speech development. Hearing thresholds recorded at a modulation frequency of 40 Hz are presented in Tables 3 and 4.

[0053]

[0054] Next, we compared the hearing thresholds recorded at two modulation frequencies (40 and 90 Hz) at each of the carrier frequencies (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz). In this example, the difference between the hearing thresholds at all carrier frequencies (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz) was no more than 5 dB.

[0055] Conclusion. The use of the proposed method allowed us to suspect (identify) the patient's cognitive impairment and refer him to a specialist for a detailed diagnosis and rehabilitation measures.

[0056] Industrial applicability

[0057] The presented examples confirm the implementation of the claimed method and the achievement of the technical result.

[0058] The claimed method allows for the diagnosis of cognitive impairment in patients without regard to their age, and also minimizes the influence of subjective factors during its implementation.

[0059] Bibliography:

[0060] 1 Scheperle RA, Abbas PJ. Relationships Among Peripheral and Central Electrophysiological Measures of Spatial and Spectral Selectivity and Speech Perception in Cochlear Implant Users. Ear Hear. 2015 Jul- Aug;36(4):441-53. doi: 10.1097 / AUD.0000000000000144. PMID: 25658746; PMCID: PMC4478147.

[0061] 2. Shahmiri, E., Jafari, Z., Noroozian, M., Zendehbad, A., Haddadzadeh Niri, H., & Yoonessi, A. (2017). Effect of Mild Cognitive Impairment and Alzheimer's Disease on Auditory Steady-State Responses. Basic and Clinical Neuroscience, 8(4), 299-306. https: / / doi.org / 10.18869 / NIRP.BCN.8.4.299.

[0062] 3. Avtenyuk AC, Makarov IV, Emelina DA, Gasanov RF, Kravchenko IV, Prokhorenko ES Cognitive deficit in children (literature review). Bekhterev Review of Psychiatry and Medical Psychology. 2022; 56:4:8-17. https: / / doi.org / 10.31363 / 2313-7053-2022-4-8-17.

[0063] 4. Nemkova S.A., Maslova O.I., Karkashadze G.A., Zavadenko N.N., Kurbatov Yu.N. Cognitive impairment in children with cerebral palsy (structure, diagnosis, treatment). Pediatric pharmacology. 2012; 9:3:77-84.

[0064] 5. Panasyuk A. Yu. Adapted version of D. Veksler's WISC method. Institute of Child and Adolescent Hygiene, Leningrad Pediatric Medical Institute. Moscow, 1973. 79 p.

[0065] 6. Naumova I.V., Gadaleva S.V., Pashkov A.V. Stationary auditory potentials. Literature review. Russian Otolaryngology. 2018; 3:115-128.

[0066] 7. Patent No. 2836018 C1 Russian Federation, IPC A61 B 5 / 12. Method for diagnosing autism spectrum disorders in a patient: declared 08.04.2024: published 10.03.2025. Pashkov A. V., Ustinova N. V., Fatakhova M. T., Namazova-Baranova L. S., Gorbunova E. A.; applicant Federal State Budgetary Scientific Institution "Russian Scientific Center of Surgery named after Academician B. V. Petrovsky".

[0067] 8. Instructions for use for the Eclipse device, manufactured by Interacustics.

Claims

1. A method for determining the probability of the presence of cognitive pathology in patients, characterized by the fact that: A) two electrodes are attached to the scalp of a sleeping patient in the vertex area or along the midline of the forehead and one electrode above the right and left mammillary processes; B) electronic wires from a device for recording short-latency auditory evoked potentials (SLEPs) of the brain and stationary auditory potentials are connected to the electrodes; B) the interelectrode resistance is checked, after which an acoustic signal is sent through in-ear headphones located in each external auditory canal, or headphones that are placed on each auricle; D) to assess the auditory function, ABR is recorded and the V peak is recorded at a stimulus intensity of 20 dB above the hearing threshold; D) after this, stationary auditory evoked potentials are simultaneously recorded for each ear at a modulation frequency of 90 Hz at carrier frequencies of 500, 1000, 2000 and 4000 Hz at a stimulus intensity of 50 dB; E) when recording a response to a stimulus of a given intensity, it is reduced in steps of 10 dB until the moment when the response ceases to be recorded, and then increased in steps of 5 dB; G) if a response to a stimulus with an intensity of 50 dB is not recorded, then it is increased in 10 dB increments and when recording a response, it is decreased in 5 dB increments; After diagnostics at stages A-G, if cognitive pathology is suspected in the patient, stationary auditory evoked potentials are recorded at a modulation frequency of 40 Hz, then a comparison is made of the hearing thresholds recorded at two modulation frequencies of 40 and 90 Hz at each of the carrier frequencies of 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, if the difference between the hearing thresholds at all carrier frequencies does not exceed 5 dB, then the patient is referred for consultation to specialized specialists to assess the cognitive status.

2. The method according to paragraph 1, characterized in that at stage A two electrodes are fixed in the vertex region, one of them positive, and the second of them reference.

3. The method according to paragraph 1, characterized in that at stage A, negative electrodes are fixed over the right and left mammillary processes.

4. The method according to paragraph 1, characterized in that at stage B the interelectrode resistance should be no more than 5 kOhm.

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