Study Of Sensorineural Hearing Loss Research Articles

Generation of an induced pluripotent stem cell line (KEIUi008-A) from a hearing loss patient with an A1555G mutation in mitochondrial DNA

We report the establishment of a human induced pluripotent stem cell (iPSC) line from a 54-year-old male patient with an A1555G mutation in the mitochondrial 12S ribosomal RNA gene (MTRNR1), associated with sensorineural hearing loss. The established iPSC line expressed stemness markers or undifferentiated state markers. We also demonstrated the capacity of the cells to differentiate into the three germ layers, suggesting its pluripotency and utility in the pathological study of sensorineural hearing loss and drug screening for ear disorders.

A Prospective Comparative Study of Sensorineural Hearing Loss in Patients of Head and Neck Cancers Treated with 2-D RT vs 3-D CRT

Background: SNHL is disabling for the patient, since it has a chronic and often Progressive natural history. sensorineural hearing loss is irreversible, whereas conductive hearing loss (as often found after radiotherapy) is mainly reversible. Material and Methods: This prospective randomized study was conducted in Department of Radiation Oncology, S P medical college Bikaner, Rajasthan. The study was done from November 2020 to October 2021. After taking informed consent total of 50 patients of biopsy proven squamous cell carcinoma of head and neck region randomly distributed among Group A who received 2D RT (2Gy/Fr in 30 to 35 fractions for 6 to 7 weeks) and Group B who received 3D CRT (2Gy/fr) in 30 to 35 fractions for 6 to 7 weeks).Result: After completion of treatment SNHL assessment was done in patients treated with conventional and conformal radiotherapy which was for speech frequency 15% and 8 % respectively and for high frequency was 45% and 28% respectively. After 3 month of completion SNHL for speech frequency 27.5% and 12% respectively and for high frequency was 62.5% and 32% respectively. Conclusion: High-frequency hearing loss can have a significant impact on quality of life because it affects speech discrimination, conventional radiotherapy experienced greater hearing loss as compared of conformal.

Study of sensorineural hearing loss in children with type 1 diabetic mellitus and the corelation with the duration of the disease in a tertiary care center

Background: Annual type 1 diabetes cases in children under the age of 15 are estimated to be around 96,000 worldwide. The pathophysiological explanation for diabetes-related hearing loss is speculative. Usually, hearing loss is bilateral, gradual onset, affecting higher frequencies. It is a well-known entity in type 2 diabetic mellitus. This study aims at knowing the prevalence of hearing loss in children with type 1 diabetic mellitus with respect to duration of diabetic mellitus. Materials and Methods: A hospital-based comparative study was conducted involving 60 diabetic children and 60 healthy (control) children. Brainstem evoked response audiometry test was done in both groups. Reports were compared and prevalence of sensorineural hearing loss in diabetic children and the corelation with the duration of disease were analyzed. Results: The mean age among cases was 11.93±2.9 years and the mean age among controls was 9.08±1.92 years. Among diabetic group, 25 (41.7%) were male, 35 (58.3%) were female. Among non-diabetic group, 33 (55%) were male, 27 (45%) were female. Although none of the diabetic children had hearing loss, the differences in absolute latency waves I, II, III, IV, and V between diabetic group and non-diabetic group in the right ear and waves I and II and III and V between diabetic group and non-diabetic group in the left ear was found to be statistically significant (p<0.05). The difference in interpeak latency values of wave I and wave V between diabetic and non-diabetic group in right ear and between wave I–V and wave III–V in the left ear was found to be statistically strongly significant (p<0.001). This indicates prolonged absolute latency and interpeak latency among diabetics than non-diabetics. Since none of the diabetic children had hearing loss, the corelation of hearing loss with the duration of the disease was unable to obtain. Conclusion: This study stresses on the need for frequent follow-up and hearing evaluation of the type 1 diabetic children for the early detection of hearing loss.

Neural Degeneration in Normal-Aging Human Cochleas: Machine-Learning Counts and 3D Mapping in Archival Sections.

Quantifying the survival patterns of spiral ganglion cells (SGCs), the cell bodies of auditory-nerve fibers, is critical to studies of sensorineural hearing loss, especially in human temporal bones. The classic method of manual counting is tedious, and, although stereology approaches can be faster, they can only be used to estimate total cell numbers per cochlea. Here, a machine-learning algorithm that automatically identifies, counts, and maps the SGCs in digitized images of semi-serial human temporal-bone sections not only speeds the analysis, with no loss of accuracy, but also allows 3D visualization of the SGCs and fine-grained mapping to cochlear frequency. Applying the algorithm to 62 normal-aging human ears shows significantly faster degeneration of SGCs in the basal than the apical half of the cochlea. Comparison to fiber counts in the same ears shows that the fraction of surviving SGCs lacking a peripheral axon steadily increases with age, reaching more than 50% in the apical cochlea and almost 66% in basal regions.

A prospective cohort study of sensorineural hearing loss associated with Kawasaki disease.

About 60 cases of sensorineural hearing loss (HL) have been reported in patients with Kawasaki disease (KD), but the current estimate of its prevalence is uncertain. The present study aimed to determine the prevalence and risk factors of sensorineural HL associated with KD. The present, prospective cohort study, conducted from May 2019 to May 2020, evaluated patients with a diagnosis of KD who received the initial therapy and underwent two auditory brainstem response (ABR) tests. HL was defined as a threshold of 40dB or more, and borderline hearing was defined as a threshold of 30dB. In total, 107 patients were enrolled, and 75 underwent two ABR tests. Thirty-one patients (30.0%) received prednisolone with their initial intravenous immune globulin and acetylsalicylic acid therapy. HL was present in only one patient who had congenital conductive HL. Five patients had borderline hearing but had normal hearing behavior. There was no significant difference between the patients with normal hearing and those with borderline hearing in terms of the clinical variables. In Japan, the prevalence of sensorineural HL after KD is not high. It may therefore be unnecessary to perform routine hearing tests for all patients with KD. Association between Kawasaki Disease and Sensorineural Hearing Loss. UMIN000037019 (the date of registration: June 11, 2019).

Prevalence of hearing loss in patients with Sjögren syndrome: a systematic review and meta-analysis.

Sjögren syndrome (SS) is a multisystem autoimmune disease, primarily targeting salivary and lacrimal glands; skin, nasal and vaginal dryness, along with musculoskeletal pain and fatigue are the most commonly reported symptoms. Hearing loss is hypothesized to be frequent as well. The purpose of this systematic review was to estimate the prevalence of Hearing loss and its different subtypes in patients with Sjögren syndrome. PRISMA guidelines were followed to ensure highest quality for our systematic review. A random effects model meta-analysis and meta-regression was conducted using I2 as heterogeneity indicator. Eleven observational studies were included in this systematic review. Ten of them were cross-sectional, while one study was case-control. Studies were assessed for risk of bias: all were rated to a moderate level, except for two rated to a low level. Pooled prevalence of any type of hearing loss was 52.2%. After excluding studies rated to moderate bias, the pooled prevalence of hearing loss was 36.7%. We also conducted a subgroup analysis depending on type of hearing loss. Pooled prevalence of sensorineural hearing loss was 42.6%., while pooled prevalence of conductive hearing loss and mixed hearing loss were 5% and 2.3%, respectively. Meta-regression was conducted in an effort to identify possible variables capable to explain high heterogeneity between studies. Sample size and year of study were separately found to account for a portion of heterogeneity between studies of sensorineural hearing loss. Year of study was also found to account for a portion of heterogeneity between studies of conductive hearing loss. In conclusion, sensorineural hearing loss, is highly prevalent in patients with Sjögren syndrome. On this basis, early screening and follow-up of patients with Sjögren syndrome by pure tone audiometry is important.

A study of sensorineural hearing loss in hypothyroidism patients and its association with thyroid stimulating hormone levels

<p><strong>Background:</strong> The most common symptom of hypothyroidism regarding ear, nose and throat is hearing insufficiency accompanied with cochleovestibular symptoms such as tinnitus, dizziness.</p><p><strong>Methods:</strong> This was a hospital based observational clinical study conducted in Rajarajeswari medical college between December 2016 to June 2018. Patients with hypothyroidism attending department of ENT-HNS that satisfied the inclusion and exclusion criteria were included in the study. Patients were subjected to pure tone audiometry, thyroid function test after detailed history and physical examination. PTA was recorded and average of 500 Hz, 1 kHz and 2 kHz were taken as the pure tone average.<strong></strong></p><p><strong>Results:</strong> 150 patients were included in the study. Mean age of patients with hearing loss was 37.2 years. 84.3% were females. 41 patients presented to us with unilateral hearing loss and 10 patients had bilateral hearing loss. 43 (84.3%) patients had mild degree of hearing loss, 8 (15.7%) had moderate hearing loss. Patients with hearing loss had altered TSH levels. Significant correlation (p<0.001) was found between hearing loss and duration of hypothyroidism, mean TSH levels.<strong></strong></p><p><strong>Conclusions:</strong> It was found that hy­pothyroidism affects the hearing producing hearing impairment, ranging from mild to moderate in severity and had significant correlation between duration of hypothyroidism and mean TSH levels with the severity of hearing loss.<strong></strong></p>

A study of sensorineural hearing loss in a tertiary care centre.

A study of sensorineural hearing loss in a tertiary care centre.

Cross sectional study of sensorineural hearing loss in type 2 diabetes mellitus

<p class="abstract"><strong>Background:</strong> The objective of the study was to evaluate the prevalence of sensorineural hearing loss in type 2 diabetes mellitus and to figure out a relation between age, sex, duration of diabetes and diabetic control.</p><p class="abstract"><strong>Methods:</strong> A cross-sectional study was conducted at Geetanjali Medical College and Hospital for 1.5 years. Patients were known case of diabetes mellitus type 2 without any other systemic illness included in the study. A total of 115 patients were involved in the study and the informed consent was taken. A detailed examination and history related to hearing loss and diabetes status with treatment was elicited. All basic blood investigations were performed on all the patients. All the patients were subjected to pure tone audiometry and impedance audiometry in a sound proof room. </p><p class="abstract"><strong>Results:</strong> The total prevalence of sensorineural hearing loss in the study subjects was found to be 80% with most of them having mild degree of sensorineural deafness. Increase in age, longer duration and uncontrolled diabetes are the factors which had higher risk of developing sensorineural hearing loss in the study subjects.</p><p class="abstract"><strong>Conclusions:</strong> There is a strong association between sensorineural hearing loss and duration of diabetes mellitus-2. The threshold of hearing loss is increased mainly at the higher frequencies with diabetes.</p>

A Study of Sensorineural Hearing Loss in Chronic Suppurative Otitis Media

A Study of Sensorineural Hearing Loss in Chronic Suppurative Otitis Media

Prospective study of sensorineural hearing loss in patients of head and neck cancers after radiotherapy and chemotherapy

Prospective study of sensorineural hearing loss in patients of head and neck cancers after radiotherapy and chemotherapy

A Study of Sensorineural Hearing Loss (SNHL) in Patients with Chronic Suppurative Otitis Media (CSOM) Coming to Otorhinolaryngology (ENT) Out-Patient Department

A Study of Sensorineural Hearing Loss (SNHL) in Patients with Chronic Suppurative Otitis Media (CSOM) Coming to Otorhinolaryngology (ENT) Out-Patient Department

Synaptopathy in the noise-exposed and aging cochlea: Primary neural degeneration in acquired sensorineural hearing loss

The classic view of sensorineural hearing loss (SNHL) is that the “primary” targets are hair cells, and that cochlear-nerve loss is “secondary” to hair cell degeneration. Our recent work in mouse and guinea pig has challenged that view. In noise-induced hearing loss, exposures causing only reversible threshold shifts (and no hair cell loss) nevertheless cause permanent loss of >50% of cochlear-nerve/hair-cell synapses. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair cell loss and threshold elevation. This primary neural degeneration has remained hidden for three reasons: 1) the spiral ganglion cells, the cochlear neural elements commonly assessed in studies of SNHL, survive for years despite loss of synaptic connection with hair cells, 2) the synaptic terminals of cochlear nerve fibers are unmyelinated and difficult to see in the light microscope, and 3) the degeneration is selective for cochlear-nerve fibers with high thresholds. Although not required for threshold detection in quiet (e.g. threshold audiometry or auditory brainstem response threshold), these high-threshold fibers are critical for hearing in noisy environments. Our research suggests that 1) primary neural degeneration is an important contributor to the perceptual handicap in SNHL, and 2) in cases where the hair cells survive, neurotrophin therapies can elicit neurite outgrowth from spiral ganglion neurons and re-establishment of their peripheral synapses.This article is part of a Special Issue entitled <Auditory Synaptology>.

Etiological study of sensorineural hearing loss in children and adults in Béni-Mellal, Morocco

Etiological study of sensorineural hearing loss in children and adults in Béni-Mellal, Morocco

Hot Topics—Hidden hearing loss: Permanent cochlear-nerve degeneration after temporary noise-induced threshold shift

The classic view of sensorineural hearing loss (SNHL) is that the “primary” targets are hair cells, and that cochlear-nerve loss is “secondary” to hair cell degeneration. Our work in mouse and guinea pig has challenged that view. In noise-induced hearing loss, exposures causing only reversible threshold shifts (and no hair cell loss) nevertheless cause permanent loss of &amp;gt;50% of cochlear-nerve/hair-cell synapses. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair cell loss and threshold elevation. This primary neural degeneration has remained hidden for two reasons: (1) the spiral ganglion cells, the cochlear neural elements commonly assessed in studies of SNHL, survive for years despite loss of synaptic connection with hair cells, and (2) the degeneration is selective for cochlear-nerve fibers with high thresholds. Although not required for threshold detection in quiet (e.g., threshold audiometry, auditory brainstem response threshold), these high-threshold fibers are critical for hearing in noisy environments. Our research suggests that (1) primary neural degeneration is an important contributor to the perceptual handicap in SNHL, and (2) noise exposure guidelines should be re-evaluated, as they are based on the faulty premise that threshold audiograms are the most sensitive measures of noise damage.

The Study of Sensorineural Hearing Loss in Pseudoexfoliation Syndrome

Purpose: Determine hearing thresholds at sound frequencies important for speech comprehension in subject with ocular pseudoexfoliation (PXF) and to compare them with that of control without PXF. Method: 60 subjects with ocular PXF and 60 age and sex matched controls without PXF were enrolled in this case-control study. Pure tone audiometry (bone conduction) was performed at 1,2 and 3 kilohertz (KHz) in all subjects. Thresholds were compared to an age and sex stratified standard (ISO7029) and between study groups. Hearing loss was defined as sum of tested hearing thresholds (HTL-1,2,3) lower than the ISO7029 standard median. Results: The study included 35 males and 25 females subject in each group. Hearing loss was present in 97 of 120 (80.83%) of examined ears in the case group Vs 52 of 120 (43.3%) in the control group [P<0.001; odds ratio(OR) = 5.51; 95% confidence interval (CI) ]. overall 54 subjects ( 90%) in the case group Vs 37 subjects 61.6 % in the control group had hearing loss in one or both ears (P<0.001; odds ratio(OR) = 5.5; 95% confidence interval. Hearing thresholds at each of the examined frequencies and the HTL- 1,2,3 were also significantly higher in individuals with PXF. Conclusions: Hearing thresholds at frequencies which are important for speech comprehension are significantly worse in individuals with ocular PXF as compared to matched controls. This finding may support the multi-organ nature of PXF syndrome.

Inner Hair Cells Are Not Required for Survival of Spiral Ganglion Neurons in the Adult Cochlea

Studies of sensorineural hearing loss have long suggested that survival of spiral ganglion neurons (SGNs) depends on trophic support provided by their peripheral targets, the inner hair cells (IHCs): following ototoxic drugs or acoustic overexposure, IHC death is rapid whereas SGN degeneration is always delayed. However, recent noise-trauma studies show that SGNs can die even when hair cells survive, and transgenic mouse models show that supporting cell dysfunction can cause SGN degeneration in the absence of IHC pathology. To reexamine this issue, we studied a model of IHC loss that does not involve noise or ototoxic drugs. Mice lacking the gene for the high-affinity thiamine transporter (Slc19a2) have normal cochlear structure and function when fed a regular (thiamine-rich) diet. However, dietary thiamine restriction causes widespread, rapid (within 10 d) loss of IHCs. Using this model, we show that SGNs can survive for months after IHC loss, indicating that (1) IHCs are not necessary for neuronal survival, (2) neuronal loss in the other hearing loss models is likely due to effects of the trauma on the sensory neurons or other inner ear cells, and (3) that other cells, most likely supporting cells of the organ of Corti, are the main source of SGN survival factors. These results overturn a long-standing dogma in the study of sensorineural hearing loss and highlight the importance of cochlear supporting cells in neuronal survival in the adult inner ear.

Prospective study of sensorineural hearing loss following radiotherapy for nasopharyngeal carcinoma

To investigate the severity and incidence of sensorineural hearing loss in patients with nasopharyngeal carcinoma treated with radiotherapy. Forty-two patients with nasopharyngeal carcinoma were treated with conventional radiotherapy. Audiological testing was performed to compare patients' hearing before and at varying stages after radiotherapy. At one month post-radiation, a significant hearing threshold increase was seen only for high frequencies. At 12, 24 and 60 months post-radiation, significant threshold increases were observed at speech frequencies (4.0 and 8.0 kHz), compared with pre-radiation data. The mean values of wave I, III and V latencies and of the I-V interpeak latency intervals were not significantly altered at one month post-radiation, but were significantly prolonged at 12, 24 and 60 months post-radiation, compared with pre-radiation data. In patients with nasopharyngeal carcinoma treated with radiotherapy, the severity and incidence of radiation-induced sensorineural hearing loss increased with time, especially at high frequencies. This hearing impairment may be due to changes in the cochlea and/or the retrocochlear auditory pathway.

A 10-Year Prospective Study of Sensorineural Hearing Loss in Children with Congenital Cytomegalovirus Infection

A 10-Year Prospective Study of Sensorineural Hearing Loss in Children with Congenital Cytomegalovirus Infection

A 10-Year Prospective Study of Sensorineural Hearing Loss in Children with Congenital Cytomegalovirus Infection

A 10-Year Prospective Study of Sensorineural Hearing Loss in Children with Congenital Cytomegalovirus Infection