Long-term Sensorineural Hearing Loss Research Articles

Abnormal cerebellar network and effective connectivity in sudden and long-term sensorineural hearing loss.

Sudden sensorineural hearing loss (SSNHL) is a common otology emergency and some SSNHL will develop into a long-term hearing loss (LSNHL). However, whether SSNHL and LSNHL have similar psychiatric patterns remains unknown, as well as the neural substrates. Increasing evidence has proved that the cerebellar network plays a vital role in hearing, cognition processing, and emotion control. Thus, we recruited 20 right SSNHL (RSSNHL), 20 right LSNHL (RLSNHL), and 24 well-matched healthy controls to explore the cerebellar patterns among the three groups. Every participant underwent pure tone audiometry tests, neuropsychological evaluations, and MRI scanning. Independent component analysis (ICA) was carried out on the MRI data and the cerebellar network was extracted. Granger causality analysis (GCA) was conducted using the significant cerebellar region as a seed. Pearson’s correlation analysis was computed between imaging characteristics and clinical features. ICA found the effect of group on right cerebellum lobule V for the cerebellar network. Then, we found decreased outflow from right cerebellum lobule V to right middle orbitofrontal cortex, inferior frontal gyrus, anterior cingulate cortex, superior temporal gyrus, and dorsal lateral prefrontal cortex in RSSNHL group in GCA analysis. No significance was found in RLSNHL subjects. Additionally, the RSSNHL group showed increased effective connectivity from the right middle frontal gyrus (MFG) and the RLSNHL group showed increased effective connectivity from the right insula and temporal pole to the right cerebellum lobule V. Moreover, connections between right cerebellum lobule V and mean time series of the cerebellar network was negatively correlated with anxiety score in RSSNHL and negatively correlated with depression scores in RLSNHL. Effective connectivity from right MFG to right cerebellum lobule V could predict anxiety status in RSSNHL subjects. Our results may prove potential imaging biomarkers and treatment targets for hearing loss in future work.

Long-Term Sensorineural Hearing Loss in Patients With Blast-Induced Tympanic Membrane Perforations.

To describe characteristics of sensorineural hearing loss (SNHL) in patients with blast-induced tympanic membrane (TM) perforations that required surgery. A retrospective review of hearing outcomes in those who had tympanoplasty for combat blast-induced TM perforations. These were sequential cases from one military otolaryngologist from 2007 to 2012. A total of 87 patients were reviewed, and of those, 49 who had appropriate preinjury, preoperative, and long-term audiograms were included. Those with pre-existing hearing loss were excluded. Preinjury audiograms were used to assess how sensorineural thresholds changed in the ruptured ears, and in the contralateral ear in those with unilateral perforations. The mean time from injury to the final postoperative audiogram was 522 days. In the ears with TM perforations, 70% had SNHLs of 10 dB or less (by bone conduction pure tone averages). Meanwhile, approximately 8% had threshold shifts >30 dB, averaging 50 dB. The strongest predictor of severe or profound hearing loss was ossicular discontinuity. Thresholds also correlated with bilateral injury and perforation size. In those with unilateral perforations, the SNHL was almost always larger on the side with the perforation. Those with SNHL often had a low-to-mid frequency threshold shift and, in general, audiograms that were flatter across frequencies than those of a typical population of military personnel with similar levels of overall hearing loss. There is a bimodal distribution of hearing loss in those who experience a blast exposure severe enough to perforate at least one TM. Most ears recover close to their preinjury thresholds, but a minority experience much larger sensorineural threshold shifts. Blast exposed ears also tend to have a flatter audiogram than most service members with similar levels of hearing loss.

Prefrontal-Temporal Pathway Mediates the Cross-Modal and Cognitive Reorganization in Sensorineural Hearing Loss With or Without Tinnitus: A Multimodal MRI Study.

Objective: Hearing loss, one main risk factor of tinnitus and hyperacusis, is believed to involve significant central functional abnormalities. The recruitment of the auditory cortex in non-auditory sensory and higher-order cognitive processing has been demonstrated in the hearing-deprived brain. The dorsolateral prefrontal cortex (dlPFC), which has dense anatomical connections with the auditory pathway, is known to play a crucial role in multi-sensory integration, auditory regulation, and cognitive processing. This study aimed to verify the role of the dlPFC in the cross-modal reorganization and cognitive participation of the auditory cortex in long-term sensorineural hearing loss (SNHL) by combining functional and structural measurements.Methods: Thirty five patients with long-term bilateral SNHL and 35 matched healthy controls underwent structural imaging, resting-state functional magnetic resonance imaging (rs-fMRI), diffusion tensor imaging (DTI), and neuropsychological assessments. Ten SNHL patients were with subjective tinnitus.Results: No differences in gray matter volume, spontaneous neural activity, or diffusion characteristics in the dlPFC were found between the SNHL and control groups. The functional connectivity (FC) between the dlPFC and the auditory cortex and visual areas, such as the cuneus, fusiform, lingual cortex, and calcarine sulcus was increased in patients with SNHL. ANOVA and post hoc tests revealed similar FC alterations in the SNHL patients with and without tinnitus when compared with the normal hearing controls, and SNHL patients with and without tinnitus showed no difference in the dlPFC FC. The FC in the auditory cortex was associated with the symbol digit modality test (SDMT) scores in the SNHL patients, which reflect attentional function, processing speed, and visual working memory. Hearing-related FC with the dlPFC was found in the lingual cortex. A tract-based spatial statistics (TBSS) analysis revealed decreased fractional anisotropy (FA) values, mainly in the temporal inferior fronto-occipital fasciculus (IFOF), which showed remarkable negative correlations with the mean hearing thresholds in SNHL.Conclusion: Higher functional coupling between the dlPFC and auditory and visual areas, accompanied by decreased FA along the IFOF connecting the frontal cortex and the occipito-temporal area, might mediate cross-modal plasticity via top-down regulation and facilitate the involvement of the auditory cortex in higher-order cognitive processing following long-term SNHL.

Investigation of congenital CMV infection with the presence of CMV DNA in saliva samples of new born babies

Cytomegalovirus (CMV), is the most common cause among congenital infections and is the most seen etiology in long-term sensorineural hearing loss (SNHL) and neurological impairment. Congenital CMV infection (CCMV) was reported in 0.15-2.2% of live-borne neonates in studies from different countries. A significant proportion of infected infants are asymptomatic after birth and might only be detected by routine screening methods during the new born period. The aim of this study was to screen the saliva of live-born neonates with areal-time PCR based method for the detection of CCMV in our hospital. Saliva samples collected in half an hour after birth by dry dacron swabs and were evaluated for CMV DNA (Rt-PCR, Abbott Molecular USA) from 1000 babies born in Ege University Faculty of Medicine Hospital Obstetrics Clinic between October 2015-October 2017. For the confirmation of CCMV, saliva positive newborns were evaluated with the same method for CMV DNA from their urine or blood within 21 days. All newborns were screened for sensorineural hearing tests. Subjects were 497 girls (49.7%) and 503 boys (50.3%), with a mean weight of 3116.8 g and mean of 37.61 birth week. CMV DNA was positive in the saliva of 16 newborns (1.6%). Fourteen newborns were weakly positive for CMV DNA in their saliva and were not confirmed for CCMV infection. Congenital CMV was confirmed in only two (0.2%) with the CMV DNA results in urine and/or blood samples. One of the two newborns with CCMV was symptomatic and had a neurosensorial hearing loss. The other one was asymptomatic. Saliva samples, taken immediately after birth with a noninvasive and easy method for the detection of CMV DNA is very important for diagnosis of CCMV. Positive samples should be confirmed with CMV DNA in urine or blood samples of these newborns. In this study, detection of positivity in saliva samples that were confirmed with other samples of our newborn population for CCMV was 0.2%. The specific diagnosis for CCMV in newborns with a noninvasive and easy collecting sample is important to avoid sequelae and for public health concerns.

Abnormal functional connectivity and degree centrality in anterior cingulate cortex in patients with long-term sensorineural hearing loss.

Wide-ranging functional remodeling is involved in sensorineural hearing loss (SNHL), which has been demonstrated to have accumulated risk of cognitive and emotional dysfunction. Anterior cingulate cortex (ACC) has close connections with the auditory area and plays a vital role in regulating the cognitive, emotional and auditory processing. However, the functional reorganization of the ACC and its associations with potential cognitive and emotional impairments involved in SNHL have never been explored. Thirty-five patients with long-term bilateral SNHL and thirty-five well-matched healthy controls were recruited for this study. We analyzed resting-state functional MRI data and neuropsychological test scores from these participants. Functional connectivity of the ACC subdivisions, voxel-wise degree centrality (DC) and intra-/internetwork connectivity were computed to evaluate the functional changes related to cognitive, emotional and multiple sensory functions. ANCOVA and post hoc analyses were conducted to identify differences between normal controls and patients for each measure. Widespread alterations of functional coupling with the subdivisions of the ACC were observed in regions involved in cognitive, emotional and multiple sensory processing, particularly within the cingulo-opercular network (CON), default mode network (DMN) and auditory network (AN) in the SNHL patients. Outstandingly increased DC was found in the ACC. Network analyses showed significant intra- and inter-network hypo-synchronization in the SNHL patients. Importantly, the functional alterations were associated with the anxiety states and the processing speed. The functional reorganization in the ACC and the disturbance of intrinsic multiple network functional connectivity among the CON, DMN, and AN were found in the SNHL patient, which might shed more lights on potential substrates underlying the cognitive and emotional impairments related to the SNHL.

Dysconnectivity Involving Multiple Resting-State Networks Associated with Cognitive and Emotional Functions in Long-Term Sensorineural Hearing Loss Patients

Background: Sensorineural hearing loss (SNHL) is accepted to involve wide-ranging functional reorganization, which is associated with accumulating risk of cognitive and emotional dysfunction. The coordination of multiple functional networks supports normal brain functions. However, the evaluation of the functional connectivity (FC) pattern involving multiple resting-state networks (RSNs), and the correlations between the functional remodeling of RSNs and the potential cognitive or emotional impairments in SNHL have never been conducted. Methods: 30 long-term bilateral SNHL patients and 39 well-matched healthy controls were recruited for assessment of resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological test. Findings: Using independent component analysis (ICA), 11 RSNs were identified. Relative to the healthy controls, the SNHL population presented apparent abnormalities of intra-network FC involving right frontoparietal network (rFPN), posterior temporal network (pTMN) and sensory motor network (SMN). Disrupted between-network FC were also revealed in the SNHL patients across both higher-order cognitive control networks and multiple sensory networks. Eight of the eleven RSNs showed altered functional synchronization using a seed network to whole brain FC method, particularly in the ventromedial prefrontal cortex (vmPFC). Besides, these functional abnormalities were correlated with cognition- and emotion-related performances. Interpretations: These findings supported our hypotheses that long-term SNHL involves notable dysconnectivity of multiple RSNs. This study provided important insights into the pathophysiological mechanisms of SNHL, and shed more lights on the neural substrates underlying the possible cognitive and emotional dysfunctions following SNHL, which would make sense to find the potential biomarker for clinical applications. Funding: This work is funded by the National Natural Science Foundation of China (NOs. 81520108015 and 81230034), the Fundamental Research Funds for the Central Universities (NO. 2242018k30004) and the National Key Basic Research Program of China (NOs. 2013CB733800 and 2013CB733803). Declaration of Interest: None of the materials in this manuscript has been published. All the authors have approved the manuscript. There are no potential conflicts of interests to declare. Ethical Approval: This work was proved by the Ethics Committee of Affiliated Zhongda Hospital of Southeast University, and the informed consent was obtained from each of the participants before the experiments.

Long-term Incidence and Degree of Sensorineural Hearing Loss in Otosclerosis.

1) To evaluate the long-term incidence and degree of the sensorineural component of hearing loss (SNHL) in patients with otosclerosis after accounting for expected age-related hearing loss. 2) To identify variables that might predict development of sensorineural hearing loss due to otosclerosis. Retrospective audiometric database and chart review. Tertiary referral center. Consecutive patients with otosclerosis observed between 1994 and 2004, with ≥10 years follow-up, excluding patients with postoperative hearing loss or surgery before the initial audiogram. Bone conduction (BC) thresholds at 0.5, 1, 2, and 4 kHz and Word Recognition. BC threshold change (BCTC) over ≥10 years minus estimated age-related threshold change (ARTC) specific to age and sex for each patient (based on ISO 7029 reference population). Three-hundred fifty-seven ears (290 patients) met study criteria, including 217 ears that had undergone stapedectomy during the study period. Mean follow-up was 14.0 years. The average BCTC after subtracting estimated ARTC was 4.6, 2.6, 3, and 2.7 dB for 0.5, 1, 2, and 4 kHz frequencies, respectively. However, 34% of ears (122 ears) had clinically significant progression of SNHL during the study period (>10 dB BCTC beyond expected ARTC at ≥2 frequencies). Multivariate analysis demonstrated that the probability of developing clinically significant SNHL was higher for women (odds ratio 1.86, p = 0.018) and lower for operated patients (odds ratio 0.46, p = 0.002). The average long-term sensorineural hearing loss due to otosclerosis was statistically significantly more than for age alone at each frequency, but these average values (from 2.6 to 4.6 dB for tested frequencies) were clinically insignificant. Approximately one-third of patients with otosclerosis demonstrated a clinically significant progression of the sensorineural component of hearing loss, with the average BCTC above expected age-related changes ranging from 10.2 to 14.6 dB for tested frequencies among this subgroup.