Frequency-Following Response and Auditory Behavior in Children with Prenatal Exposure to the Zika Virus

Introduction Prenatal exposure to the Zika virus can impair neurodevelopment and cause auditory damage. Objective To analyze the frequency-following response (FFR) and the auditory behavior (with the LittlEars ® questionnaire) of children with and without prenatal exposure to Zika virus infection. Methods A total of 30 children participated in the present study, divided into 3 groups: 10 children with microcephaly and prenatal exposure to the Zika virus; 10 normocephalic children with prenatal exposure to the Zika virus; and 10 children with no evidence of prenatal exposure to the virus. The FFR test was performed with the /da/ syllable. The LittlEars ® questionnaire was used with parents/guardians. Results For the FFR measurements, there was no difference between the groups. The children with exposure to the Zika virus presented a final score in the questionnaire below what is expected from children with normal hearing. A significant difference was observed for the final, semantic, and expressive scores between the group with microcephaly and the other groups. A strong negative correlation was seen between the LittlEars ® questionnaire final score and the FFR measurements for the group with microcephaly when compared with the other groups. Conclusion Children exposed to the Zika virus, with and without microcephaly, presented FFR patterns similar to what was seen in children with no evidence of virus exposure. However, they showed signs of immature auditory behavior, suggesting auditory development delay.

Adolescents' Self-Perception about Auditory Behavior: Agreement with Parents and Central Auditory Processing Evaluation

Introduction Central auditory processing disorder (CAPD) has been diagnosed through behavioral tests. Moreover, screening tools as validated questionnaires may contribute to identify individuals at risk for this disorder, including adolescents. Objective (1) to characterize and compare adolescents' self-perception regarding their auditory behavior with their parents' perception; (2) to verify their agreement with behavioral evaluation of central auditory processing (CAP). Methods Cross-sectional, prospective, and descriptive study, in which 40 adolescents and 40 parents of both genders participated. All participants answered the scale of auditory behaviors questionnaire, and the behavioral evaluation of CAP was conducted with the adolescents. Findings were analyzed descriptively and inferentially, with a significance level of 5% (p ≤ 0.05) and application of the following tests: Test for equality of two proportions, Chi-squared, and Kappa concordance index. Results Most adolescents rated their auditory behavior as “low risk” for CAPD while their parents rated it as “typical.” When comparing adolescents' self-perception and parents' perception about the auditory behavior with the behavioral evaluation outcome, a statistically significant difference was observed only in adolescents' self-perception. The results of the behavioral evaluation indicated that 42.5% of the adolescents showed alterations. The concordance index between adolescents' self-perception and parents' perception of auditory behavior showed a significant (minimal) difference. Conclusion Most adolescents were able to perceive difficulties regarding their auditory behavior and characterized it as “low risk” for CAPD, but the same did not occur regarding their parents. There was agreement only between the adolescents' self-perception and their performance in the behavioral evaluation of CAP.

Altered Cerebellar White Matter in Sensory Processing Dysfunction Is Associated With Impaired Multisensory Integration and Attention

Sensory processing dysfunction (SPD) is characterized by a behaviorally observed difference in the response to sensory information from the environment. While the cerebellum is involved in normal sensory processing, it has not yet been examined in SPD. Diffusion tensor imaging scans of children with SPD (n = 42) and typically developing controls (TDC; n = 39) were compared for fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) across the following cerebellar tracts: the middle cerebellar peduncles (MCP), superior cerebellar peduncles (SCP), and cerebral peduncles (CP). Compared to TDC, children with SPD show reduced microstructural integrity of the SCP and MCP, characterized by reduced FA and increased MD and RD, which correlates with abnormal auditory behavior, multisensory integration, and attention, but not tactile behavior or direct measures of auditory discrimination. In contradistinction, decreased CP microstructural integrity in SPD correlates with abnormal tactile and auditory behavior and direct measures of auditory discrimination, but not multisensory integration or attention. Hence, altered cerebellar white matter organization is associated with complex sensory behavior and attention in SPD, which prompts further consideration of diagnostic measures and treatments to better serve affected individuals.

Measuring implanted patient response to tone pips

Background An electrical potential not previously reported—electrical cochlear response (ECR)—observed only in implanted patients is described. Its amplitude and growth slope are a measurement of the stimulation achieved by a tone pip on the auditory nerve. The stimulation and recording system constructed for this purpose, the features of this potential obtained in a group of 43 children, and its possible clinical use are described. The ECR is obtained by averaging the EEG epochs acquired each time the cochlear implant (CI) processes a tone pip of known frequency and intensity when the patient is sleeping and using the CI in everyday mode. The ECR is sensitive to tone pip intensity level, microphone sensitivity, sound processor gain, dynamic range of electrical current, and responsiveness to electrical current of the auditory nerve portion involved with the electrode under test. It allows individual evaluation of intracochlear electrodes by choosing, one at the time, the central frequency of the electrode as the test tone pip frequency, so the ECR measurement due to a variable intensity tone pip allows to establish the suitability of the dynamic range of the electrode current. Results There is a difference in ECR measurements when patients are grouped based on their auditory behavior. The ECR slope and amplitude for the Sensitive group is 0.2 μV/dBHL and 10 μV at 50 dBHL compared with 0.04 μV/dBHL and 3 μV at 50dBHL for the Inconsistent group. The clinical cases show that adjusting the dynamic range of current based on the ECR improved the patient’s auditory behavior. Conclusions ECR can be recorded regardless of the artifact due to the electromyographic activity of the patient and the functioning of the CI. Its amplitude and growth slope versus the intensity of the stimulus differs between electrodes. The relationship between minimum ECR detection intensity level and auditory threshold suggests the possibility of estimating patient auditory thresholds this way. ECR does not depend on the subject’s age, cooperation, or health status. It can be obtained at any time after implant surgery and the test procedure is the same regardless of device manufacturer.

Using a screening tool to identify the auditory behavior of students who are learning to read and write

ABSTRACT Purpose: to analyze the use of a screening tool, by teachers, to identify the auditory behavior of students who are learning to read and write. Methods: a cross-sectional study including 22 students who answered the Fisher’s Auditory Problems Checklist (QFISHER). The analysis of this questionnaire approached the categories of hearing, attention, memory, language, and school performance. The chi-square statistical test and Mann-Whitney test were used to compare the scores between the age groups, considering the 5% significance level. Results: school performance had the worst frequency in QFISHER (87.72%), followed by attention (62.10%), language (60.53%), and hearing (59.65%). The median revealed worse assessment in school performance (100.0%) followed by attention (60.0%). The QFISHER overall score was 66.7%. The comparison between age groups did not reveal any significant difference for the domains assessed. Conclusion: the QFISHER, used by teachers, as a screening tool for children who are learning to read and write, can identify behavioral changes suggestive of auditory processing disorder, broadening the possibility of early interventions.

Altered cerebellar white matter in sensory processing dysfunction is associated with impaired multisensory integration and attention

Sensory processing dysfunction (SPD) is characterized by a behaviorally observed difference in the response to sensory information from the environment. While the cerebellum is involved in normal sensory processing, it has not yet been examined in SPD. Diffusion tensor imaging scans of children with SPD (n=42) and typically developing controls (TDC; n=39) were compared for fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) across the following cerebellar tracts: the middle cerebellar peduncles (MCP), superior cerebellar peduncles (SCP), and cerebral peduncles (CP). Compared to TDC, children with SPD show reduced microstructural integrity of the SCP and MCP, which correlates with abnormal auditory behavior, multisensory integration, and attention, but not tactile behavior or direct measures of auditory discrimination. In contradistinction, decreased CP microstructural integrity in SPD correlates with abnormal tactile and auditory behavior and direct measures of auditory discrimination, but not multisensory integration or attention. Hence, altered cerebellar white matter organization is associated with complex sensory behavior and attention in SPD, which prompts further consideration of diagnostic measures and treatments to better serve affected individuals.

Auditory cortex shapes sound responses in the inferior colliculus

The extensive feedback from the auditory cortex (AC) to the inferior colliculus (IC) supports critical aspects of auditory behavior but has not been extensively characterized. Previous studies demonstrated that activity in IC is altered by focal electrical stimulation and pharmacological inactivation of AC, but these methods lack the ability to selectively manipulate projection neurons. We measured the effects of selective optogenetic modulation of cortico-collicular feedback projections on IC sound responses in mice. Activation of feedback increased spontaneous activity and decreased stimulus selectivity in IC, whereas suppression had no effect. To further understand how microcircuits in AC may control collicular activity, we optogenetically modulated the activity of different cortical neuronal subtypes, specifically parvalbumin-positive (PV) and somatostatin-positive (SST) inhibitory interneurons. We found that modulating the activity of either type of interneuron did not affect IC sound-evoked activity. Combined, our results identify that activation of excitatory projections, but not inhibition-driven changes in cortical activity, affects collicular sound responses.

Time-compressed speech test in adults with and without central auditory processing disorders

ABSTRACT Purpose: to analyze and compare the performance in the time-compressed speech test and the auditory behavior of adults with and without central auditory processing disorders. Methods: an observational, analytical, cross-sectional study with a total of 40 people of both genders aged 18 to 35 years participating in the study. They were submitted to anamnesis, basic audiological assessment, and a core battery of tests for central auditory processing - including the dichotic digits test (binaural integration), frequency pattern test, and time-compressed speech test (TCST). Based on the results of the dichotic digits and frequency pattern tests, the subjects were divided into two groups, with and without central auditory processing disorders. The auditory behavior was assessed with the Scale of Auditory Behavior (SAB) questionnaire. The Mann-Whitney and Fisher’s exact tests were used for the statistical analysis, setting the significance level at p < 0.05. Results: no difference in performance was found between the groups regarding the ears. There was a difference between the groups only in the time-compressed speech test with monosyllable stimuli in the left ear (p = 0.026). Monosyllables were the words that resulted in most errors. Conclusion: it was verified that only the list of stimuli influenced the performance, differing the individuals with and without central auditory processing disorders. There was an association of auditory behavior, analyzed with the SAB questionnaire, with the performance in the TCST with the list of monosyllables. It is suggested that this list be used when assessing adults by the time-compressed speech test.