Sudden Hearing Loss Waves: The Effect of COVID-19 Infection and Vaccination on the Inner Ear.

Sudden sensorineural hearing loss (SSNHL) has emerged as a potential complication of COVID-19 infection and vaccination. Various mechanisms by which the SARS-CoV-2 virus can cause hearing loss have been reported, including direct viral invasion, neuroinflammation, blood flow disturbances, and immune-mediated response. However, the temporal relationship between COVID-19 infection and SSNHL remains unclear, with mixed findings and conflicting results reported in different studies. Similarly, while anecdotal reports have linked COVID-19 vaccination to SSNHL, evidence remains scarce. Establishing a correlation between COVID-19 vaccines and SSNHL implies a complex and multifactorial pathogenesis involving interactions between the immune system and the body's stress response. Nevertheless, it is important to consider the overwhelming evidence of the vaccines' safety and efficacy in limiting the spread of the disease and remains the primordial tool in reducing death.

Sudden hearing loss secondary to syphilis.

BACKGROUND: Syphilis is a sexually transmitted disease caused by the spirochete Treponema pallidum, whose incidence has increased significantly in recent years. Some patients may develop sudden hearing loss (SHL) against the background of otosyphilis. OBJECTIVES: The objective of our study was to determine whether routine lues serology is useful in patients presenting with sudden hearing loss. METHODS: For this purpose, all cases of SHL treated in our hospital during a period of 6 years were propectively collected. The frequency of positivity for syphilis in these patients, the treatment received, and their evolution were determined. RESULTS: Of the total number of patients evaluated during that period, 71 underwent serological screening for syphilis, of whom 2 (2.8 %) presented positive screening antibodies. In one of them, the RPR was normal and had been treated with lues a few years before. After treatment there was no improvement. The other patient, diagnosed with otosyphilis with unconfirmed suspected neurological disease, showed normalization of hearing after specific treatment. CONCLUSIONS: Since it is a potentially curable disease, despite the low overall frequency of syphilis in patients with SHL it is advisable to perform serological screening for syphilis in high risk patients (e.g., incarceration, multiple recent sexual partners, men who have sex with men) or atypical clinical presentation (e.g., concurrent neuropathies).

Importance of early objective auditory testing in the presentation of sudden sensorineural hearing loss in children.

BACKGROUND: Functional hearing loss can be due to an auditory manifestation of functional neurological disorder, previously known as conversion disorder. METHODS: This is a case series of 3 pediatric patients with a diagnosis of idiopathic SSNHL who ultimately were found to have functional neurological disorder. RESULTS: Average age was 12.7 years at presentation (range 10-14 years). All three patients underwent invasive interventions prior to their initial clinic visit. All patients demonstrated profound SNHL on behavioural audiogram, but normal otoacoustic emissions (OAE) and auditory brainstem response testing. With counselling, both patients demonstrated significant hearing improvement. CONCLUSIONS: Early use of OAE's in the workup of SSNHL can avoid unnecessary and potentially harmful therapies and expedite access to counselling services which may help lead to symptom resolution.

Cochlear implantation in patients with Charcot-Marie-Tooth disease: two cases with a review of the literature.

PURPOSE: To report two cases of bilateral cochlear implantation (CI) in Charcot-Marie-Tooth disease (CMT) patients with novel mutations. Furthermore, we conducted a detailed literature review on the profile and outcomes of CI in this uncommon clinical circumstance. CASE PRESENTATION: Case 1 involved a 25-year-old woman who was referred for sudden hearing loss (HL) in her left ear and had a 7-year history of HL in her right ear. She was diagnosed with CMT type 1 with a thymidine phosphorylase gene mutation. CI was performed on her left side because her hearing gradually worsened to deafness in both ears. At 3 months post-operation, her speech discrimination score without lip-reading improved from 0 to 100%. She underwent a second CI on her right ear 6 months after her first CI. Two years from her first operation, the speech discrimination score was 100%. Case 2 received her first CI on her right ear at the age of nine for her bilateral HL. She was diagnosed with CMT type 2 with a Twinkle mitochondrial DNA helicase gene mutation. Preoperatively, the speech discrimination score in both ear-aided conditions was 70%. At the 7-year post-operation follow-up, the speech discrimination score was 76%. A second CI was performed due to decreasing hearing ability in her left ear. The speech discrimination score showed 100% at 7 months after the second CI. CONCLUSIONS: CI is an effective hearing rehabilitation option for CMT patients with severe-to-profound SNHL. Neuro-otologists should consider CI as a treatment option, even though hearing loss in CMT is associated with auditory neuropathy spectrum disease (ANSD).

Prevalence of perilymphatic fistula in patients with sudden-onset sensorineural hearing loss as diagnosed by Cochlin-tomoprotein (CTP) biomarker detection: its association with age, hearing severity, and treatment outcomes.

PURPOSE: To determine the prevalence of perilymphatic fistula (PLF) in sudden-onset sensorineural hearing loss (SSNHL) patients by employing the Cochlin-tomoprotein (CTP) detection test, a specific diagnostic marker for perilymph. We also analyzed the clinical characteristics associated with hearing outcomes in this cohort. METHODS: A total of 74 eligible patients were prospectively enrolled. Following myringotomy, middle ear lavage (MEL) samples underwent the CTP test to identify perilymph leakage. Intratympanic dexamethasone (IT-DEX) therapy was administered, and hearing outcomes were assessed. Control groups comprised patients with chronic otitis media (n = 40) and non-inflammatory middle ears (n = 51) with concurrent MEL sample collection. RESULTS: CTP was positive in 16 (22%) patients. No control samples showed positive results. Multiple regression analysis indicated that age and pre-treatment hearing levels significantly contributed to the CTP value. We found a positive correlation between CTP values, age, and pre-treatment pure-tone averages. Notably, CTP values in SSNHL cases aged 60 and above were significantly higher than in those below 60 years. Patients with positive CTP had significantly worse recovery rates after IT-DEX treatment. CONCLUSION: This study is the first prospective investigation demonstrating a positive relationship between CTP values, age, and hearing severity in SSNHL, indicating that PLF might be the essential cause of SSNHL, particularly in the elderly. Our findings suggest that IT-DEX may be less effective for PLF-associated SSNHL. Future research could reveal that PLF repair surgery is a viable treatment strategy for SSNHL. This study was registered under the UMIN Clinical Trials Registry (UMIN000010837) on 30/May/2013.

The value of gadolinium-enhanced MRI in predicting the development of sudden hearing loss into Ménière's disease.

OBJECTIVE: To compare the clinical features of sudden hearing loss (SHL) in patients with and without endolymphatic hydrops (EH), and to investigate the association between SHL with EH and Ménière's disease (MD). METHODS: The clinical data of 63 SHL patients with first symptoms were evaluated retrospectively. Patients were separated into two groups based on the results of gadolinium-enhanced magnetic resonance imaging: EH and non-EH groups. Independent sample t-test and U-test were used to compare groups for continuous variables, and the chi-squared test, corrected chi-squared test and Bonferroni correction test were used to compare groups for binary and ordinal variables. The binary logistic regression model was utilised for univariate and multivariate analysis of follow-up patient prognosis. RESULTS: The EH and non-EH groups contained 32 and 31 patients, respectively. The EH group had a higher prevalence of low-tone descending hearing loss. Fifty-one patients were followed for more than 2 years. In the EH group, 11 and 15 patients were diagnosed with sudden sensorineural hearing loss (SSNHL) and MD, respectively, while in the non-EH group, 24 patients were diagnosed with SSNHL and only one with MD. EH, low-tone descending hearing loss and vertigo were risk factors for the diagnosis of MD in a subgroup univariate regression analysis of patients experiencing SHL. EH was found to be a risk factor for the progression of SHL into MD in a multifactor regression analysis. CONCLUSIONS: Patients with SHL who have EH are more likely to present with low-tone descending hearing loss. EH is a risk factor for the subsequent development of MD.

Analysis of hearing prognosis risk factors in pediatric unilateral sudden sensorineural hearing loss.

OBJECTIVES: Pediatric idiopathic sudden hearing loss (PISSNHL) is a rare disease with no established factor affecting its prognosis. In this study, we investigate the risk factors affecting the prognosis of PISSNHL. MATERIAL AND METHODS: Among the patients who visited our hospital from January 2010 to December 2021, the characteristics associated prognosis of 54 patients with unilateral PISSNHL were retrospectively confirmed. RESULTS: Patients' recovery was determined by applying Siegel's criteria (SC) and AAO-HNS criteria (AC). Twenty-seven (50 %) and 29 patients (54.3 %) recovered for SC and AC, respectively. Age, sex, side, duration between onset and treatment, administration of intra-tympanic steroid injection, accompanying symptoms (tinnitus and dizziness), BMI, serum creatinine level, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte count (PLR), lymphocyte count, and platelet count were not significantly different between the recovery group and the poor recovery group (P > 0.05). The patients were divided into five groups according to the initial hearing of the affected ear and again according to their audiogram type. The initial hearing levels, hearing level severity, and the audiogram type were significantly different between the deaf group (>100 dB HL) and the non-deaf group (P < 0.05). CONCLUSION: The prognosis of PISSNHL is closely related to the initial hearing at the onset. If the initial hearing level is <100 dB, the recovery rate is approximately 50 %, therefore requiring active treatment and emotional support. It may also be related to the type of audiometric curve.

COVID-19 and transtympanic injections for sudden sensorineural hearing loss.

BACKGROUND: Multiple reports have linked COVID-19 infection with sudden sensorineural hearing loss (SSNHL), although other studies have failed to demonstrate this association. The current study was conceived to examine the rates of SSNHL across a large, principally national, population by characterizing the rate of transtympanic injections for SSNHL during the pandemic. METHODS: Retrospective review of all patients that underwent transtympanic injection from 2019 to 2020. RESULTS: Covering a unique beneficiary population of 9.6 million individuals of all ages in the United States, a statistically significant decrease in transtympanic injections for SSNHL was performed from 2019 to 2020 (p = 0.04, IRR = 0.91, 95 % CI = 0.84-0.99). No patient receiving a transtympanic injection also had a COVID-19 diagnosis. CONCLUSIONS: These findings support the idea that COVID-19 infections do not clinically significantly increase patients' risk of developing SSNHL. In fact, the decreased exposure through social isolation to other common viruses implicated in causing SSNHL may have actually led to a lower rate of SSNHL during the pandemic.

Neurovascular conflict and sudden unilateral sensorineural hearing loss: coincidence or coexistence?

OBJECTIVE: To study the association between neurovascular conflict (NVC) of the 8th cranial nerve (CN8) and unilateral sudden sensorineural hearing loss SSNHL (SSNHL). METHODS: A systematic literature search of "MEDLINE" via "PubMed," "Embase," and "Google-Scholar" was conducted. Meta-analysis of pooled data was performed for NVC prevalence of SSNHL affected ears versus controls. RESULTS: The literature search identified 941 publications, of which, 9 included in qualitative synthesis (1030 ears) and 5 in quantitative synthesis (484 ears). NVC was as prevalent as 0.8-69% for affected ears and as 19-57% for controlled ears. No association between MRI protocol and NVC prevalence was proved. An odds ratio of 1.05 (95% confidence interval = 0.79-1.39) was calculated for association of NVC in unilateral SSNHL ears versus controls. CONCLUSION: The prevalence of NVC of CN8 in unilateral SSNHL affected ears is not significantly bigger than controls. Hence, NVC of CN8 is probably NOT associated with unilateral SSNHL.

The association between metabolic syndrome and the prognosis of idiopathic sudden sensorineural hearing loss.

INTRODUCTION: In this study, we investigated the association between metabolic syndrome and the prognosis of idiopathic sudden sensorineural hearing loss. METHODS: In this prospective cohort study, 79 patients with idiopathic SSNHL admitted to the ENT ward were involved. Patients were under treatment with two-dose pulse methylprednisolone and then oral corticosteroid (Prednisolone 1 mg/kg for up to 2 weeks and more). In all patients, the mean hearing threshold was measured before treatment and 3 weeks after the treatment. Metabolic syndrome criteria were assessed in all patients too. Then, based on these diagnostic criteria all data in patients with and without metabolic were compared. RESULTS: There was a significant difference in Hypertension, BMI > 25, high TG and low HDL (p.v = 0.001) between two groups (metabolic syndrome group and non-metabolic syndrome group). The rate of recovered patients was significantly lower in the metabolic syndrome group than in the non-metabolic syndrome group (p.v = 0.001). It was found that metabolic syndrome (OR = 2.02), diabetes mellitus (OR = 7.32), HTN (OR = 4.09), BMI > 25 (OR = 3.24) and high initial hearing threshold (OR = 3.96) were clearly related to the poor prognosis of treatment. CONCLUSIONS: According to the findings of this study, it was found that metabolic syndrome had a negative effect on hearing improvement in patients with idiopathic SSNHL.

The association between COVID-19 vaccination and idiopathic sudden sensorineural hearing loss, clinical manifestation and outcomes.

PURPOSE: Previous data demonstrated an increased incidence of Idiopathic Sensorineural Hearing Loss (ISSNHL) in 2021 compared to 2019-2020, suggesting an association with the anti-COVID-19 vaccine. We aimed to assess our center's incidence and compare the clinical manifestations and outcomes of vaccinated vs. unvaccinated patients. METHODS: A retrospective chart review of all patients diagnosed with ISSNHL during 2021 was conducted and compared to patients who presented in 2018-2020. Patient demographics, audiometry features, vaccination status, and prognosis were evaluated. RESULTS: Throughout 2021, 51 patients were diagnosed with ISSNHL, compared with 31 during 2020, 38 in 2019, and 41 in 2018, demonstrating a 64%, 34%, and 24% increase, respectively. Among patients who presented in 2021, 13 (25.4%) received the anti-COVID-19 vaccine within 30 days before their presentation, and 4 received it within 96 h. Most presented after receiving the second or third dose. Patient characteristics, audiometry features, and prognosis did not significantly differ between vaccinated and unvaccinated patients. CONCLUSIONS: A marked incline was seen in the 2021 ISSNHL incidence at our medical center, of which 25% of cases were within a month post-anti-COVID-19 vaccination. No significant difference was found in clinical manifestations and outcomes between vaccinated and nonvaccinated patients. While other justifications could be sought, an association cannot be ruled out, and further research is needed.

Characteristics of sudden hearing loss after different COVID-19 vaccinations: a systematic review and meta-analysis.

INTRODUCTION: COVID-19 vaccines are essential to prevent complications and reduce the burden of SARS-CoV-2. However, these vaccines showed side effects such as fatigue, pain, fever, and rarely hearing loss. In this review, we aim to summarize studies investigating hearing loss following COVID-19 vaccination and try to find the possible association and risk factors for this hazardous complication. METHODS: We performed a comprehensive search of five electronic databases (PubMed, Scopus, Web of Science, google scholar, Cochrane) from inception until 9 October 2022. We finally included 16 studies after the first and second scans. We used SPSS to analyze the extracted data. RESULTS: A total of 630 patients were identified, with a mean age of 57.3. Of the patients, 328 out of 609 vaccinated patients took the Pfizer-BioNTech BNT162b2 vaccine, while 242 (40%) took the Moderna COVID-19 vaccine. The mean time from vaccination to hearing impairment was 6.2, ranging from a few hours to one month after the last dose. The results found a significant difference between vaccine types in terms of incidence and prognosis of the condition, while they showed that the number of doses prior to the onset had no significance. CONCLUSION: SNHL has been reported in a small number of people who have received the COVID-19 vaccine, but it is unclear at this time whether the vaccine is directly causing this condition. However, the COVID-19 vaccine has been demonstrated to be safe and effective in preventing illness, and the benefits of vaccination are significant compared to any potential risks. PROTOCOL REGISTRATION: The protocol of this study was registered on Prospero CRD42022367180.

Sudden sensorineural hearing loss after Covid-19 infection.

Covid-19 pandemic has taken the world by a storm, pushing the boundaries of human endurance and intellect. Caught at the horns of dilemma, humanity is still struggling with the management of the established symptoms not to mention the novel symptoms. In this regard, the novel symptoms must be highlighted to ensure proper and timely management. Viral aetiology has been an established entity for neurological deficits; hence, it would not be a huge leap to consider the correlation between Covid-19 and Sensorineural hearing loss (SNHL). Here, a case is being presented where the patient developed sudden sensorineural hearing loss after Covid-19 infection.

Diabetes Mellitus and Hearing Loss: A Complex Relationship.

Background and Objectives: Discussion is open about the relationship between diabetes (DM) and hearing loss (HL). There is a lot of evidence in the literature suggesting a causal link between these conditions, beyond being considered simple comorbidities. The difficulty in identifying populations free from confounding factors makes it difficult to reach definitive conclusions on the pathophysiological mechanisms at play. Nonetheless, there is numerous evidence that demonstrates how the population affected by DM is more affected by sensorineural HL (SNHL) and exhibit a higher prevalence of idiopathic sudden sensorineural HL (ISSNHL). Materials and Methods: Articles reporting potentially relevant information were reviewed, and the most significant results are discussed in this article. Starting from the possible mechanisms relating to auditory impairment in the diabetic condition, this article summarizes the studies on auditory evaluation in subjects with DM1 and DM2 and addresses the relationship between DM and ISSNHL. Results: DM is considered a risk factor for SNHL, although some studies have reported no relationship when the associations were adjusted for age, gender, and hypertension. Macro and microvascular insults that cause decreased blood flow, oxygen exchange, and ion transport are major complications of hypertension and DM and can have a direct effect on the sensory and support cells of the cochlea. Conclusions: Given the difficulty of carrying out studies on populations without confounding factors, new laboratory studies are strongly required to clarify which specific physiopathological mechanisms underlie the diabetic damage caused to the hearing organs and how pharmacological management may contribute to counteracting the pathophysiological effects of the diabetic condition on the auditory system.

The Role of Fibrinogen, Homocysteine and Metabolic Syndrome's Alterations in Sudden Sensorineural Hearing Loss (SSHL): A Narrative Review.

Fibrinogen and homocysteine (HCY) are molecules known to play a role in vascular homeostasis, and their blood levels are often elevated in patients with metabolic syndrome. Recent evidence suggests that sudden sensorineural hearing loss (SSHL) may have a vascular origin. This has led many authors to advocate that fibrinogen, homocysteine, and metabolic syndrome (MetS) may play a direct role in SSHL. The aim of this brief review is to examine the role and influence of these molecules and MetS on the mechanisms of SSHL. Elevated fibrinogen levels have been associated with a worse prognosis in SSHL, possibly due to increased blood viscosity and decreased blood flow. Similarly, HCY has been associated with vascular damage, particularly in hyperhomocysteinemia, although the exact association with SSHL remains controversial. MetS has been demonstrated to function both as a causative factor and as a contributor to poorer recovery in cases of SSHL. However, although some studies suggest a possible role for these biomarkers and MetS in the prognosis and treatment of SSHL, specific therapeutic and preventive strategies based solely on these factors have yet to be developed. Given their potential role in prognosis and treatment and the global epidemic of metabolic syndrome, this issue needs to be analyzed comprehensively. Thus, further quality studies need to be conducted, even though it is difficult to determine the actual impact of MetS on the development of SSHL, as it is a multifactorial disease affecting multiple organs.

Prognostic Value of Early Magnetic Resonance Imaging Patterns in Sudden Hearing Loss.

INTRODUCTION: Sudden sensorineural hearing loss (SSHL) is a relatively frequent disease, but a sensitive marker or a reliable test to identify the underlying cause is still unavailable. Neuroradiology appears to offer the most promising tools, especially magnetic resonance imaging (MRI). In a recent study from our group, we explored the ability of MRI to detect subtle changes in the inner ear compartments by means of a 3D-fluid-attenuated inversion recovery sequence, aiming at identifying 3 distinct MRI patterns (haemorrhagic, inflammatory, brain-labyrinth barrier breakdown). In the present study, we contrasted the MRI patterns at onset with relevant prognostic factors, with the audiological features of each patient's SSHL and with treatment outcomes. METHODS: In this retrospective study, we enrolled 50 adult subjects (54.61 ± 18.26 years) with SSHL. They underwent an MRI within 72 h from admission, and 5 audiological evaluations: at admission, on the 5th day after the start of medical therapy, at the end of the first cycle of hyperbaric oxygen therapy, then 1 and 6 months later. RESULTS: Abnormalities of the MRI signal and/or post-contrast enhancement asymmetry of the cochlea ("pattern+ MRI") correlated with worse audiological outcomes at 1 month, but the different MRI patterns were not correlated with any specific prognostic model, despite rigid protocol settings. However, a significant difference was found for low-tone SSHL, which were always "pattern" negative at MRI (p = 0.01), and for profound SSHL which demonstrated a pattern+ MRI in 80% (p = 0.04). At the onset of SSHL, a pattern+ MRI was found in 29/50 cases (58.0%) and was related with lesser degree of recovery of pure-tone average at 1 month and lesser chance to retain the hearing threshold benefit in the long term. Given the limited numbers of patients enrolled so far, the relative impact of comorbidities on each MRI pattern remains uncertain. At 6 months, we observed a trend of greater and more stable recovery (p = 0.023) and less frequent recurrence of SSHL in patients with a normal MRI. CONCLUSIONS: The 3 observed MRI patterns did not correlate consistently with specific audio-vestibular features or any peculiar aspect of the patient's clinical history. Larger series of patients with SSHL are needed, possibly from multicentric studies.

Sudden onset hearing loss as initial presentation of Susac syndrome: a rare case report and brief review.

Susac syndrome is a rare disease presenting with a classic triad of symptoms. These are sensorineural hearing loss, encephalopathy, and branch retinal artery occlusions. Initial presentation is usually headache and symptoms of encephalopathy. Hearing loss is unusual in the early stages but, when it does present, can often lead to a misdiagnosis of sudden sensorineural hearing loss. Hence, neurological and retinal examinations are essential to an accurate diagnosis. In this study, we aimed to raise awareness of Susac syndrome among physicians and facilitate recognition of its manifestation, especially in those patients presenting with hearing loss alone. Identifying Susac syndrome that presents as sudden sensorineural hearing loss can be challenging but a number of case reviews have been reported in recent years and treatment guidelines are available.

Acute bilateral hearing loss as a rare presentation of acute stroke.

Acute bilateral hearing loss is an uncommon presentation in the Emergency Department (ED), with a variety of potential causes. It is important to consider neurologic vascular etiologies as a cause for acute sensorineural hearing loss. We report a case of acute hemorrhagic stroke presenting as acute bilateral hearing loss. A 60-year-old male with a history of atrial fibrillation presented to the ED with the acute onset of bilateral hearing loss with otherwise intact neurologic testing. He was found to have an acute left temporal hemorrhagic stroke, and magnetic resonance imaging demonstrated multifocal ischemia including an acute right temporal ischemic stroke. In the ED setting, cerebrovascular pathology is an important consideration in the patient presenting with acute hearing loss in the absence of an alternative diagnosis. Missing such a diagnosis can lead to significant morbidity and mortality.

Labyrinthine lesions in presumed inner ear hemorrhage-related sudden deafness.

PURPOSE: Inner ear hemorrhage (IEH) is a rare cause of sudden sensorineural hearing loss (SSNHL). This study aimed to evaluate the lesional patterns in patients with presumed IEH from morphological and functional aspects. METHODS: Seventeen patients with SSNHL and presumed IEH who completed audio-vestibular tests were included. The main outcome measures included clinical characteristics, radiology, and functional test results. RESULTS: The morphological findings and functional tests revealed differences in locations and lesional spectrums. The magnetic resonance imaging (MRI) hyperintensity was likely to involve the vestibule (88.2%), the cochlea (76.5%), and the posterior and lateral semicircular canals (76.5% and 70.6%, respectively). Furthermore, 70.6% of cases showed abnormality in the entire labyrinth, and abnormalities in the vestibule/semicircular canals were observed in 17.6% of cases. Meanwhile, dysfunction was sequentially detected in the cochlea (100%), semicircular canals (94.1%), and vestibule (70.6%); 64.7% of cases showed combined deficit in the entire labyrinth, and 29.4% of cases showed combined deficit in the cochlea/semicircular canals. Although lesions in the labyrinth were frequently detected, the results of the radiological and functional tests did not always match and significantly differed in either cochlear or superior semicircular canal damage detection (p < 0.05 each). CONCLUSIONS: In this cohort, IEH preferentially caused sudden audio-vestibular impairment, which was well demonstrated by a combination of MRI and functional tests. The specific lesional configurations revealed in this study may suggest a possible pathomechanism that could be further explored as a therapeutic target.

Clinical features and prognosis of severe-to-profound sudden sensorineural hearing loss.

PURPOSE: Sudden sensorineural hearing loss (SSNHL) is an otologic emergency. Despite multiple efforts to clarify the factors affecting the prognosis of severe-to-profound SSNHL, various studies showed inconsistent results and lack of clinical significance. Therefore, we examined the clinical features and outcomes of severe-to-profound SSNHL. MATERIALS AND METHODS: We included patients who experienced SSNHL between 2018 and 2021 and were diagnosed according to the American Academy of Otolaryngology-Head and Neck Surgery criteria; hearing loss over 70 dB on initial pure tone audiometry (PTA) was used to define severe-to-profound SSNHL. We retrospectively examine the demographic, laboratory, radiologic, and audiometric data of SSNHL patients. We also evaluated the final hearing gain of these patients by assessing their PTA findings and word-recognition scores. RESULTS: Of the 178 patients, 94 (52.81%) and 84 (47.19%) showed profound (>90 dB) and severe (>70 to 90 dB) hearing loss, respectively. The presence of vertigo and hypertension differed significantly between the severe and profound groups (p < 0.001 and p = 0.012, respectively), as did the initial serum creatinine level (p = 0.043). Recovery in PTA showed a reliable correlation with the interval between onset and treatment in the severe group and periventricular white-matter findings in the profound group (p < 0.001 and p = 0.011, respectively). The presence of hypertension was related to recovery of low tone (p = 0.023 for 250 Hz; p = 0.034 for 500 Hz), while glycated hemoglobin level was related to recovery of high tone in the severe group (p = 0.049 for 4000 Hz; p = 0.047 for 8000 Hz). CONCLUSIONS: Severe-to-profound SSNHL showed poor prognosis for hearing gain. The interval from onset to treatment was a significant prognostic factor for severe SSNHL, while the presence of vertigo, estimated glomerular filtration rate, and periventricular white-matter findings were significant prognostic factors for profound SSNHL.