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BioRxiv : the Preprint Server For... Jun 2024Fragile X syndrome (FXS) is an X-linked disorder that often leads to intellectual disability, anxiety, and sensory hypersensitivity. While sound sensitivity...
Fragile X syndrome (FXS) is an X-linked disorder that often leads to intellectual disability, anxiety, and sensory hypersensitivity. While sound sensitivity (hyperacusis) is a distressing symptom in FXS, its neural basis is not well understood. It is postulated that hyperacusis may stem from temporal lobe hyperexcitability or dysregulation in topdown modulation. Studying the neural mechanisms underlying sound sensitivity in FXS using scalp electroencephalography (EEG) is challenging because the temporal and frontal regions have overlapping neural projections that are difficult to differentiate. To overcome this challenge, we conducted EEG source analysis on a group of 36 individuals with FXS and 39 matched healthy controls. Our goal was to characterize the spatial and temporal properties of the response to an auditory chirp stimulus. Our results showed that males with FXS exhibit excessive activation in the frontal cortex in response to the stimulus onset, which may reflect changes in top-down modulation of auditory processing. Additionally, during the chirp stimulus, individuals with FXS demonstrated a reduction in typical gamma phase synchrony, along with an increase in asynchronous gamma power, across multiple regions, most strongly in temporal cortex. Consistent with these findings, we observed a decrease in the signal-to-noise ratio, estimated by the ratio of synchronous to asynchronous gamma activity, in individuals with FXS. Furthermore, this ratio was highly correlated with performance in an auditory attention task. Compared to controls, males with FXS demonstrated elevated bidirectional frontotemporal information flow at chirp onset. The evidence indicates that both temporal lobe hyperexcitability and disruptions in top-down regulation play a role in auditory sensitivity disturbances in FXS. These findings have the potential to guide the development of therapeutic targets and back-translation strategies.
PubMed: 38915683
DOI: 10.1101/2024.06.13.598957 -
Scientific Reports Jun 2024This study aims to investigate auditory hypersensitivity and cortical function in migraine patients using the Hyperacusis Questionnaire and the Event-Related Potential...
This study aims to investigate auditory hypersensitivity and cortical function in migraine patients using the Hyperacusis Questionnaire and the Event-Related Potential (ERP) technique. The study analyzes alterations in the latency and amplitude of the event-related potentials MMN and P300 components. The findings contribute to a better understanding of the physiological relationship between migraine and auditory hypersensitivity. Seventeen migraine patients were admitted to the outpatient clinic of the Department of Otorhinolaryngology-Head and Neck Surgery at Peking University People's Hospital from June 2023 to September 2023. Nineteen matched healthy subjects were also selected. All participants underwent the pure tone audiometry and the auditory brainstem response test to determine hearing thresholds, the Hyperacusis Questionnaire, the Tinnitus Handicap Inventory, and an ERP examination. The Oddball classical paradigm was used as the stimulation task, and electroencephalography signals were recorded synchronously. The scores of the Hyperacusis Questionnaire, latency and amplitude of MMN and P300 component were compared between the migraine group and the control group, and their correlation was analyzed. The latency of MMN at the Fz and Cz sites in migraine patients was significantly shorter than that in the control group (P < 0.05), and the amplitudes were significantly higher than those in the control group (P < 0.05). The variances in latency and amplitude of P300 at Cz and Pz sites in migraine patients were not statistically significant when compared with the control group. (P > 0.05). The Hyperacusis Questionnaire was negatively correlated with MMN latency, with a correlation coefficient of - 0.374 (P = 0.025), and positively correlated with MMN amplitude, with a correlation coefficient of 0.378 (P = 0.023). There was no significant similarity between the Hyperacusis Questionnaire and P300 latency and amplitude (P > 0.05). Overall, auditory hypersensitivity was enhanced in individuals with migraines compared to healthy individuals, leading to faster information processing, while there may be less impairment in cognitive function.
Topics: Humans; Female; Migraine Disorders; Male; Hyperacusis; Adult; Surveys and Questionnaires; Middle Aged; Electroencephalography; Event-Related Potentials, P300; Evoked Potentials; Case-Control Studies; Young Adult; Audiometry, Pure-Tone
PubMed: 38898084
DOI: 10.1038/s41598-024-65014-3 -
Journal of Clinical Medicine Jun 2024The purpose of this study was to investigate the hearing characteristics and causes of sudden sensorineural hearing loss (SSNHL) in patients aged from 15 to 40 years,...
The purpose of this study was to investigate the hearing characteristics and causes of sudden sensorineural hearing loss (SSNHL) in patients aged from 15 to 40 years, focusing on audiological outcomes one year after the diagnosis. The medical records of individuals with SSNHL who were referred to our tertiary-level audiologic center were reviewed. All patients had undergone comprehensive diagnostic evaluations, including high-resolution 3D-FLAIR delayed magnetic resonance imaging (MRI), cone beam computed tomography (CBCT), and screening for coagulation, infectious, and autoimmune diseases. Overall, 56 patients (mean age 28.1 ± 7.6 years) were included in the study. The hearing threshold in the affected ear improved significantly from 56.0 ± 18.0 dB at the diagnosis to 46.9 ± 22.3 dB after one year ( = 0.02). The degree of hearing loss, audiometric configurations, hearing improvements, and adherence to hearing treatments showed considerable variability among patients. Aural fullness, tinnitus, and hyperacusis were the predominant symptoms associated with SSNHL, and their prevalence decreased significantly over time. The diagnostic protocol led to the identification of the specific cause of SSNHL in 75% (42/56) of patients. The known etiology was found to be otological (39.3%), infectious (21.4%), autoimmune (7.1%), vascular (5.4%), or neoplastic (1.8%). In particular, Menière's disease (n = 12), isolated cochlear endolymphatic hydrops (n = 6), HSV-1 (n = 5), and EBV (n = 4) infections were the most frequent causes of SSNHL. The identification of the specific etiology of SSNHL may facilitate a more personalized approach to management and treatment.
PubMed: 38893014
DOI: 10.3390/jcm13113303 -
Cephalalgia : An International Journal... Jun 2024This study aimed to identify the potential subgroups of migraines based on the patterns of migraine associated symptoms, vestibular and auditory symptoms using latent...
OBJECTIVE
This study aimed to identify the potential subgroups of migraines based on the patterns of migraine associated symptoms, vestibular and auditory symptoms using latent class analysis and to explore their characteristics.
METHOD
A total of 555 patients with migraine participated in the study. Symptoms such as nausea, vomiting, photophobia, phonophobia, osmophobia, visual symptoms, vestibular symptoms (dizziness, vertigo), and auditory symptoms (tinnitus, hearing loss, aural fullness) were assessed. Latent class analysis was performed to identify subgroups of migraines. Covariates such as gender, age of migraine onset, frequency of migraine attacks per month, and family history were also considered.
RESULTS
The analysis revealed four latent classes: the Prominent Vestibular; Prominent Nausea; Presenting Symptoms but not prominent or dominant; and Sensory Hypersensitivity groups. Various covariates, such as gender, age of migraine onset, and frequency of migraine attacks, demonstrated significant differences among the four groups. The Sensory Hypersensitivity group showed the presence of multiple sensory symptoms, earlier age of migraine onset, and higher proportion of females. The Prominent Vestibular group had the highest probability of dizziness or vertigo but lacked the presence of auditory symptoms. The Prominent Nausea group exhibited prominent nausea. The Presenting Symptoms but not prominent or dominant group comprised individuals with the highest migraine attacks per month and proportion of chronic migraine.
CONCLUSION
This study identifies four subgroups of migraines based on the patterns of symptoms. The findings suggest potential different but overlapped mechanisms behind the vestibular and auditory symptoms of migraine. Considering the different patterns of migraine-related symptoms may provide deeper insights for patients' prognosis and clinical decision-making.
Topics: Humans; Migraine Disorders; Female; Male; Adult; Middle Aged; Latent Class Analysis; Vertigo; Young Adult; Nausea; Dizziness; Aged; Adolescent; Vestibular Diseases
PubMed: 38887813
DOI: 10.1177/03331024241262488 -
Frontiers in Neuroscience 2024Both tinnitus and hyperacusis, likely triggered by hearing loss, can be attributed to maladaptive plasticity in auditory perception. However, owing to their...
INTRODUCTION
Both tinnitus and hyperacusis, likely triggered by hearing loss, can be attributed to maladaptive plasticity in auditory perception. However, owing to their co-occurrence, disentangling their neural mechanisms proves difficult. We hypothesized that the neural correlates of tinnitus are associated with neural activities triggered by low-intensity tones, while hyperacusis is linked to responses to moderate- and high-intensity tones.
METHODS
To test these hypotheses, we conducted behavioral and electrophysiological experiments in rats 2 to 8 days after traumatic tone exposure.
RESULTS
In the behavioral experiments, prepulse and gap inhibition tended to exhibit different frequency characteristics (although not reaching sufficient statistical levels), suggesting that exposure to traumatic tones led to acute symptoms of hyperacusis and tinnitus at different frequency ranges. When examining the auditory cortex at the thalamocortical recipient layer, we observed that tinnitus symptoms correlated with a disorganized tonotopic map, typically characterized by responses to low-intensity tones. Neural correlates of hyperacusis were found in the cortical recruitment function at the multi-unit activity (MUA) level, but not at the local field potential (LFP) level, in response to moderate- and high-intensity tones. This shift from LFP to MUA was associated with a loss of monotonicity, suggesting a crucial role for inhibitory synapses.
DISCUSSION
Thus, in acute symptoms of traumatic tone exposure, our experiments successfully disentangled the neural correlates of tinnitus and hyperacusis at the thalamocortical recipient layer of the auditory cortex. They also suggested that tinnitus is linked to central noise, whereas hyperacusis is associated with aberrant gain control. Further interactions between animal experiments and clinical studies will offer insights into neural mechanisms, diagnosis and treatments of tinnitus and hyperacusis, specifically in terms of long-term plasticity of chronic symptoms.
PubMed: 38881748
DOI: 10.3389/fnins.2024.1385942 -
BioRxiv : the Preprint Server For... May 2024Parvalbumin-expressing inhibitory neurons (PVNs) stabilize cortical network activity, generate gamma rhythms, and regulate experience-dependent plasticity. Here, we...
Parvalbumin-expressing inhibitory neurons (PVNs) stabilize cortical network activity, generate gamma rhythms, and regulate experience-dependent plasticity. Here, we observed that activation or inactivation of PVNs functioned like a volume knob in the mouse auditory cortex (ACtx), turning neural and behavioral classification of sound level up or down over a 20dB range. PVN loudness adjustments were "sticky", such that a single bout of 40Hz PVN stimulation sustainably suppressed ACtx sound responsiveness, potentiated feedforward inhibition, and behaviorally desensitized mice to loudness. Sensory sensitivity is a cardinal feature of autism, aging, and peripheral neuropathy, prompting us to ask whether PVN stimulation can persistently desensitize mice with ACtx hyperactivity, PVN hypofunction, and loudness hypersensitivity triggered by cochlear sensorineural damage. We found that a single 16-minute bout of 40Hz PVN stimulation session restored normal loudness perception for one week, showing that perceptual deficits triggered by irreversible peripheral injuries can be reversed through targeted cortical circuit interventions.
PubMed: 38853938
DOI: 10.1101/2024.05.30.596691 -
Hearing Research Jun 2024Since the presence of tinnitus is not always associated with audiometric hearing loss, it has been hypothesized that hidden hearing loss may act as a potential trigger...
Since the presence of tinnitus is not always associated with audiometric hearing loss, it has been hypothesized that hidden hearing loss may act as a potential trigger for increased central gain along the neural pathway leading to tinnitus perception. In recent years, the study of hidden hearing loss has improved with the discovery of cochlear synaptopathy and several objective diagnostic markers. This study investigated three potential markers of peripheral hidden hearing loss in subjects with tinnitus: extended high-frequency audiometric thresholds, the auditory brainstem response, and the envelope following response. In addition, speech intelligibility was measured as a functional outcome measurement of hidden hearing loss. To account for age-related hidden hearing loss, participants were grouped according to age, presence of tinnitus, and audiometric thresholds. Group comparisons were conducted to differentiate between age- and tinnitus-related effects of hidden hearing loss. All three markers revealed age-related differences, whereas no differences were observed between the tinnitus and non-tinnitus groups. However, the older tinnitus group showed improved performance on low-pass filtered speech in noise tests compared to the older non-tinnitus group. These low-pass speech in noise scores were significantly correlated with tinnitus distress, as indicated using questionnaires, and could be related to the presence of hyperacusis. Based on our observations, cochlear synaptopathy does not appear to be the underlying cause of tinnitus. The improvement in low-pass speech-in-noise could be explained by enhanced temporal fine structure encoding or hyperacusis. Therefore, we recommend that future tinnitus research takes into account age-related factors, explores low-frequency encoding, and thoroughly assesses hyperacusis.
PubMed: 38852534
DOI: 10.1016/j.heares.2024.109050 -
Hearing Research May 2024The round window (RW) membrane plays an important role in normal inner ear mechanics. Occlusion or reinforcement of the RW has been described in the context of...
The round window (RW) membrane plays an important role in normal inner ear mechanics. Occlusion or reinforcement of the RW has been described in the context of congenital anomalies or after cochlear implantation and is applied as a surgical treatment for hyperacusis. Multiple lumped and finite element models predict a low-frequency hearing loss with air conduction of up to 20 dB after RW reinforcement and limited to no effect on hearing with bone conduction stimulation. Experimental verification of these results, however, remains limited. Here, we present an experimental study measuring the impact of RW reinforcement on the middle and inner ear mechanics with air and bone conduction stimulation. In a within-specimen repeated measures design with human cadaveric specimens (n = 6), we compared the intracochlear pressures in scala vestibuli (P) and scala tympani (P) before and after RW reinforcement with soft tissue, cartilage, and bone cement. The differential pressure (P) across the basilar membrane - known to be closely related to the hearing sensation - was calculated as the complex difference between P and P. With air conduction stimulation, both P and Pincreased on average up to 22 dB at frequencies below 1500 Hz with larger effect sizes for P compared to P. The P, in contrast, decreased up to 11 dB at frequencies between 700 and 800 Hz after reinforcement with bone cement. With bone conduction, the average within-specimen effects were less than 5 dB for either P, P or P. The inter-specimen variability with bone conduction, however, was considerably larger than with air conduction. This experimental study shows that RW reinforcement impacts air conduction stimulation at low frequencies. Bone conduction stimulation seems to be largely unaffected. From a clinical point of view, these results support the hypothesis that delayed loss of air conduction hearing after cochlear implantation could be partially explained by the impact of RW reinforcement.
PubMed: 38850830
DOI: 10.1016/j.heares.2024.109049 -
CNS & Neurological Disorders Drug... Jun 2024Recently, US Food and Drug Administration (FDA) has approved calcitonin gene-related peptide receptor antagonists (rimegepant, and ubrogepant), and selective serotonin... (Meta-Analysis)
Meta-Analysis
Safety and Efficacy of Calcitonin Gene-related Peptide Receptor Antagonists and Selective Serotonin Receptor Agonist in the Management of Migraine: A Systematic Review and Meta-analysis.
BACKGROUND
Recently, US Food and Drug Administration (FDA) has approved calcitonin gene-related peptide receptor antagonists (rimegepant, and ubrogepant), and selective serotonin receptor agonists (lasmiditan) in the management of migraine. However, the exact safety and efficacy profile of these drugs is unclear so far.
METHODS
The study's primary objective was to determine the exact safety and efficacy profile. The overall estimate was calculated in terms of risk ratios using a suitable model. The subgroup analysis was also performed to check the effect of individual drugs on the outcome, whereas sensitivity analysis was performed to check the effects of outliers on the outcome. All the analyses were performed using Rev Man 5. The drugs have shown significant improvement in efficacy parameters (pain freedom, most bothersome symptoms, phonophobia, nausea, and photophobia).
RESULTS
The subgroup analysis results have shown significant improvement in all efficacy parameters in the rimegepant and ubrogepant groups. The effect of ubrogepant on safety parameters was found to be non-significant, indicating a better safety profile of ubrogepant than lasmiditan.
CONCLUSION
The sensitivity analysis results have shown no effect of outliers on the efficacy parameters. Based on the available evidence, recently approved drugs are effective in the treatment of migraine, however, associated with few adverse drug reactions.
PubMed: 38847252
DOI: 10.2174/0118715273304677240529062909 -
Hearing Research Aug 2024Hearing loss is well known to cause plastic changes in the central auditory system and pathological changes such as tinnitus and hyperacusis. Impairment of inner ear... (Review)
Review
Hearing loss is well known to cause plastic changes in the central auditory system and pathological changes such as tinnitus and hyperacusis. Impairment of inner ear functions is the main cause of hearing loss. In aged individuals, not only inner ear dysfunction but also senescence of the central nervous system is the cause of malfunction of the auditory system. In most cases of hearing loss, the activity of the auditory nerve is reduced, but that of the successive auditory centers is increased in a compensatory way. It has been reported that activity changes occur in the inferior colliculus (IC), a critical nexus of the auditory pathway. The IC integrates the inputs from the brainstem and drives the higher auditory centers. Since abnormal activity in the IC is likely to affect auditory perception, it is crucial to elucidate the neuronal mechanism to induce the activity changes of IC neurons with hearing loss. This review outlines recent findings on hearing-loss-induced plastic changes in the IC and brainstem auditory neuronal circuits and discusses what neuronal mechanisms underlie hearing-loss-induced changes in the activity of IC neurons. Considering the different causes of hearing loss, we discuss age-related hearing loss separately from other forms of hearing loss (non-age-related hearing loss). In general, the main plastic change of IC neurons caused by both age-related and non-age-related hearing loss is increased central gain. However, plastic changes in the IC caused by age-related hearing loss seem to be more complex than those caused by non-age-related hearing loss.
Topics: Inferior Colliculi; Animals; Humans; Neurons; Auditory Pathways; Neuronal Plasticity; Hearing; Presbycusis; Auditory Perception; Age Factors; Hearing Loss; Aging; Evoked Potentials, Auditory, Brain Stem; Acoustic Stimulation
PubMed: 38797036
DOI: 10.1016/j.heares.2024.109033