Low-tone Hearing Loss Research Articles

Comparison of the outcomes of treatment with an oral diuretics with steroid and steroid only for acute low-tone hearing loss: a prospective randomized controlled trial

Comparison of the outcomes of treatment with an oral diuretics with steroid and steroid only for acute low-tone hearing loss: a prospective randomized controlled trial

A systematic review of the clinical evidence for an association between type I hypersensitivity and inner ear disorders.

Inner ear disorders have a variety of causes, and many factors can contribute to the exacerbation of cochlear and vestibular pathology. This systematic review aimed to analyze clinical data on the coexistence and potential causal interaction between allergic diseases and inner ear conditions. A search of PubMed and Web of Science identified 724 articles, of which 21 were selected for full-text analysis based on inclusion and exclusion criteria. The epidemiologic evidence found overwhelmingly supports an association between allergic disease and particular inner ear disorders represented by a high prevalence of allergic reactions in some patients with Ménière's disease (MD), idiopathic sudden sensorineural hearing loss (ISSHL), and acute low-tone hearing loss (ALHL). In addition, patients with MD, ISSHL, and ALHL had higher levels of total serum IgE than healthy subjects. Finally, in some cases, changes in cochlear potential may have been induced by antigen exposure, while desensitization alleviated allergy and inner ear-related symptoms. The exact mechanism of interaction between the auditory/vestibular and immune systems is not fully understood, and further clinical and basic research is needed to understand the relationship between the two systems fully.

Cerebellopontine angle tumor presenting as acute audiovestibular syndrome

Background Acute audiovestibular deficits may be a harbinger of vestibular schwannoma (VS). Objective To investigate clinical and laboratory features of 25 consecutive patients with VS presenting with acute audiovestibular deficits. Methods A symptomatic combination of acute audiovestibular deficits was investigated. Audiometric and vestibular function tests, and internal auditory canal magnetic resonance imaging (IAC MRI) results were evaluated. Results Varying combinations of symptoms may develop in VS patients with acute audiovestibular deficits, of whom sudden hearing loss (HL) without acute vertigo or acute facial nerve palsy (FNP) was most common. The most common audiometric configuration was high-tone hearing loss, and no patient showed low-tone hearing loss. IAC MRI demonstrated that the tumor had an intracanalicular portion and attachment to the bony IAC wall in all patients and widened the IAC wall in some patients. Conclusion Different symptomatic combinations of acute audiovestibular deficits may develop in patients with VS. Awareness about the possibility of VS as a cause of sudden HL, acute vertigo, and acute FNP, as well as subsequent IAC MRI scanning is vital to earlier diagnosis of VS in these patients.

Simulation of hearing loss can induce pitch shifts for complex tones.

Most studies on pitch shift provoked by hearing loss have been conducted using pure tones. However, many sounds encountered in everyday life are harmonic complex tones. In the present study, psychoacoustic experiments using complex tones were performed on healthy participants, and the possible mechanisms that cause pitch shift due to hearing loss are discussed. Two experiments were performed in this study. In experiment 1, two tones were presented, and the participants were asked to select the tone that was higher in pitch. Partials with frequencies less than 250, 500, 750, or 1,000 Hz were eliminated from the harmonic complex tones and used as test tones to simulate low-tone hearing loss. Each tone pair was constructed such that the tone with a lower fundamental frequency (F0) was higher in terms of the frequency of the lowest partial. Furthermore, partials whose frequencies were greater than 1,300 or 1,600 Hz were also eliminated from these test tones to simulate high-tone hearing loss or modified sounds that patients may hear in everyday life. When a tone with a lower F0 was perceived as higher in pitch, it was considered a pitch shift from the expected tone. In experiment 2, tonal sequences were constructed to create a passage of the song "Lightly Row." Similar to experiment 1, partials of harmonic complex tones were eliminated from the tones. After listening to these tonal sequences, the participants were asked if the sequences sounded correct based on the melody or off-key. The results showed that pitch shifts and the melody sound off-key when lower partials are eliminated from complex tones, especially when a greater number of high-frequency components are eliminated. Considering that these experiments were performed on healthy participants, the results suggest that the pitch shifts from the expected tone when patients with hearing loss hear certain complex tones, regardless of the underlying etiology of the hearing loss.

Acute Low-Tone (Frequency) Hearing Loss

Acute low-tone hearing loss (ALHL) or acute low-frequency hearing loss is classified as a subset of idiopathic sudden sensorineural hearing loss. The patients with ALHL tend to complain of ear fullness, tinnitus, and low tone hearing changes, rather than severe hearing loss and vertigo. Diagnostic criteria for ALHL comprise a mean hearing loss of at least 30 dB at three low frequencies (125, 250, and 500 Hz) and a mean hearing loss of 20 dB or less at three high frequencies (2, 4, and 8 kHz). ALHL is presumed to be an early stage of Meniere’s disease, because symptoms such as ear fullness, low-tone hearing loss, tinnitus, and occasional vertigo are similar between the two diseases. Progress of ALHL can be evaluated using pure tone audiometry, electro-cochloegraphy, vestibular evoked myogenic potential, and Caloric test. Patients with ALHL recovered from initial hearing loss after diuretics and full dose of steroid therapy, and the majority of hearing loss significantly recovered (more than 10 dB recovery in 83.9% of patients; 62.9%-91.3% recovery rate). The recurrence rate of hearing loss reaches 50% over 5 years, and the transition to Meniere’s disease also reaches 15.6% (10%- 24%). A low-sodium diet and plant-based diet are recommended in parallel with drug treatment. ALHL can be a common type of metabolic disease in modern civilization, and additional research will be needed.

Prognosis of Acute Low-Tone Hearing Loss Without Vertigo: A Scoping Review.

Despite its relatively high prevalence, our understanding of the natural clinical course of acute low-tone hearing loss (ALHL) without vertigo remains incomplete. The purpose of this study is to summarize the findings of studies that evaluated recovery from hearing loss (HL), recurrence and/or fluctuation of HL, and progression to Meniere's Disease (MD) of patients presenting with ALHL without vertigo. A scoping review of the English literature was performed. On May 14, 2020 and July 6, 2022, MEDLINE, Embase, and Scopus were searched to identify articles related to the prognosis of ALHL. To be included, articles had to present outcomes that were clearly distinguishable for patients with ALHL without vertigo. Two reviewers evaluated articles for inclusion and extracted data. Disagreements were adjudicated by a third reviewer. Forty-one studies were included. There was extensive heterogeneity between studies in regard to defining ALHL, treatment methods, and time of follow-up. Most of the cohorts (39 out of 40) reported partial or complete recovery of hearing in the majority (>50%) of patients, although reports of recurrence were relatively common. Progression to MD was infrequently reported. Shorter time from onset of symptoms to treatment predicted better hearing outcomes in 6 of 8 studies. The literature suggests that although the majority of patients with ALHL experience hearing improvement, recurrence and/or fluctuation are common, and progression to MD occurs in a minority of patients. Additional trials utilizing standardized inclusion and outcome criteria are needed to determine the ideal treatment for ALHL. NA Laryngoscope, 133:2457-2469, 2023.

Assessing the usefulness of inner ear contrast-enhanced magnetic resonance imaging and pure-tone audiometry in estimating the prognostic value of hearing improvement in patients with definite Meniere's disease.

Meniere's disease (MD) is characterized by combined cochlear and vestibular symptoms. However, its underlying cause remains unclear, with low-to-mid-tone hearing impairment being predominantly reported. Moreover, predicting hearing improvement after disease onset is not possible. This study aimed to assess whether hearing improvement in patients with definite MD (DMD) could be predicted using inner ear contrast magnetic resonance imaging (IEC-MRI) and pure-tone audiometry (PTA) at disease attack. Between April 2020 and March 2022, seven outpatients with DMD were enrolled based on the Bárány Society DMD criteria. The patients were divided into two groups: low-tone hearing loss (LTL) group and low-to-mid-tone hearing loss (LMTL) group. Hearing improvement rates as well as the possible inter-relation between endolymphatic hydrops and hearing improvement were evaluated. Endolymphatic hydrops was found in two of four LTL cases. One of three LMTL cases had prominent lymphedema. All patients with LTL but only one patient with LMTL had hearing improvement. Endolymphatic hydrops was not found to be correlated with hearing improvement. Estimating hearing improvement in patients with DMD using IEC-MRI was not possible. However, PTA showed better hearing prognosis in LTL than in LMTL. Therefore, estimating hearing improvement using PTA was possible at disease attack.

Predictive factors of acute sensorineural hearing loss in adult Japanese patients for clinical application by primary care doctors: a cross-sectional study

BackgroundSeveral methods are used for hearing loss screening; however, their benefits are uncertain. In this study, we aimed to determine the predictive factors of acute sensorineural hearing loss for clinical application by primary care doctors.MethodsThis retrospective, cross-sectional study included 365 patients with acute sensorineural hearing loss without prior therapy. The patients’ clinical data, demographic information, and medical histories were obtained, and they were asked about comorbidities. In addition, we assessed lifestyle factors such as stress level, alcohol consumption, marital status, and socioeconomic level. Logistic regression analysis was performed to investigate the diagnostic predictive ability of the selected factors associated with acute sensorineural hearing loss. The hearing levels of all patients were evaluated using pure tone audiometry.ResultsWe identified significant predictive factors for acute sensorineural hearing loss. The absence of hyperacusis was a predictive factor for sudden sensorineural hearing loss. Younger age, female sex, and marital status were predictive factors for acute low-tone hearing loss. High body mass index, high socioeconomic level, low alcohol consumption, high stress level, hyperacusis, and vertigo/dizziness were predictive factors for Ménière’s disease. High body mass index and ear fullness were predictive factors for perilymph fistula. Low stress level was a predictive factor for acoustic tumours.ConclusionsOur findings can be used to distinguish between the types of acute sensorineural hearing loss. Symptoms, physical status, and lifestyle factors identified during this study are useful markers for predicting acute sensorineural hearing loss occurrence.

Combination Therapy and Single-Modality Treatment for Acute Low-Tone Hearing Loss: A Meta-Analysis with Trial Sequential Analysis.

Acute low-tone hearing loss (ALHL) is a common clinical disease and was first proposed by Abe in 1981 as sensorineural hearing loss confined to low frequencies. The best strategy for initiating medication is still unclear, as the superiority of steroids and diuretics is still debated, and combination therapy might yield additional benefits. However, no study regarding combination therapy has been published. The objective of this study was to evaluate the efficacy of steroid therapy versus combination therapy of diuretics with steroids by conducting a systematic review with a meta-analysis and trial sequential analysis (TSA). Studies enrolling patients with a diagnosis of acute low-tone hearing loss were considered eligible. After searching the PubMed, Cochrane Library, Embase, Scopus and Web of Science databases from inception to 31 December 2021, five studies including 433 patients were enrolled. Overall, the comparison between combination therapy with steroids and diuretics and single-modality treatment with steroids (OR, 1.15; 95% CI, 0.51 to 2.59; p = 0.74; I2 = 34%) and the comparison between combination therapy and treatment with diuretics alone (OR, 1.73; 95% CI, 0.93 to 3.23; p = 0.09; I2 = 5%) showed that combination therapy did not confer significant benefits when compared to single-modality treatments. A trial sequential analysis (TSA) showed conclusive nonsignificant results of the comparison between the combination of steroids and diuretics and a single-modality treatment. In conclusion, we reported that the combination of steroids and diuretics did not yield significant benefits when compared to single-modality treatment with steroids or diuretics. We suggest that treatment should be initiated with steroids or diuretics alone to avoid potential adverse effects.

The value of vestibular evoked myogenic potential and electrocochleography in unexplained aural fullness

Background Unexplained aural fullness, after excluding external or middle ear diseases and vertigo, is not easily diagnosed. Aim The aim of this study is to determine the vestibular evoked myogenic potential (VEMP) and electrocochleography (ECochG) abnormal rates in patients with unexplained aural fullness, and analyzed the relationship between unexplained aural fullness and endolymphatic hydrops (EH). Material and Methods The VEMP and EcochG abnormal rates in 54 patients with unexplained aural fullness and 21 healthy volunteers, and the VEMP and EcochG abnormal rates in the four hearing loss groups were compared. The distribution of abnormal of VEMP and EcochG in age, sex or hearing loss groups were investigated. Results The VEMP abnormal rate in patients was greater than that in healthy volunteers (p = .000). The abnormal rate of VEMP was greater than the EcochG in patients (p = .003). The VEMP abnormal rate was greater than the EcochG in patient with low-tone or high-tone hearing loss (p = .008). Conclusion and significance Abnormal of VEMP in a significant proportion of patients with unexplained aural fullness maybe indicative of EH, and EH was more likely to involve the utricle or saccule in patients with low- or high-tone hearing loss.

Magnetic resonance imaging: Role on diagnosing all types of endolymphatic hydrops

This study utilized the recently advanced technique in MR imaging to establish its role on diagnosing all types of endolymphatic hydrops (EH). Twenty-two patients (26 ears) with clinical EH were admitted due to acute hearing loss and/or vertiginous attack. Each patient underwent an inner ear test battery comprising audiometry, cervical and ocular vestibular-evoked myogenic potential tests, and caloric test, followed by MR imaging for confirmation. Of the 22 clinical EH patients, 12 patients were referred to primary EH (Meniere's disease), 8 patients were secondary EH (including delayed EH in 5), and 2 patients were EH of embryopathic origin. MR imaging of 26 affected ears demonstrated EH in the cochlea only for 14 ears, in the utricle and saccule only for 1 ear, and in all three endorgans for 3 ears, accounting for a sensitivity of 69% (18/26). The 8 affected ears showing negative MR images were EH patients with hearing recovery 1, just after vertiginous attack 3, and chronic low-tone hearing loss 4. In contrast, 3 out of 18 unaffected ears demonstrated asymptomatic EH in the cochlea, representing a specificity of 83% (15/18). The sensitivity and specificity of MR imaging for confirming all types of EH were 69% and 83%, respectively. Although diagnostic criteria can identify primary and delayed EH, MR imaging may provide a supplementary tool for diagnosing secondary, embryopathic, or asymptomatic EH, if patients are not with hearing recovery, chronic low-tone hearing loss, or just after vertiginous attack.

Update on Clinical Manifestation in Acute Low-Tone Hearing Loss

Background and Objectives Acute low-tone hearing loss (ALHL) is gaining attention as an independent disease identity with close association with endolymphatic hydrops and early stage Meniere’s disease (MD). This study aims to compare patients of ALHL with patients exhibiting low-tone hearing loss and ear fullness without vertigo in various audio-vestibular assessments and in progression to overt MD.Subjects and Method A total of 249 patients with low-tone hearing loss with ear fullness without vertigo was enrolled in this study. Of these patients, 58 patients met criteria for ALHL, which was defined as having an average hearing loss of ≥30 dB at 125, 250, and 500 Hz and ≤20 dB at 2, 4, and 8 kHz. Demographics, electrocochleography (ECoG) abnormality, rate of hearing improvement, vestibular functions, and progression to MD were analyzed.Results An average low-tone hearing loss of ALHL patients was 42.8 dB, which recovered to 18.9 dB following a combined treatment of diuretics and oral steroid therapy. The hearing recovery rate of this group was 87.9% and the ECoG abnormality ratio was 42.5%. Also, 15.5% of ALHL patients eventually progressed to MD.Conclusion This study described demographics and characteristics of ALHL, demonstrating a successful response to the combined treatment of diuretics and oral steroid. Also, this report demonstrated a close relationship between the degree of low-tone hearing loss and ECoG abnormality and observed the progression to MD in ALHL patients. These data can be usefully applied in clinical setting to explain clinical outcomes of ALHL.

The Role of Anti-Endothelial Cell Autoantibodies and Immune Response in Acute Low-Tone Hearing Loss.

Immunity is associated with acute low tone hearing loss. However, the exact pathophysiology of immunity-mediated acute low tone hearing loss remains unknown. In this study, we evaluated the presence, therapeutic effectiveness, and immunopathological mechanisms of anti-endothelial cell autoantibodies (AECEs) in patients with acute low-frequency hearing loss. Forty-nine patients who were treated as inpatients having acute low-frequency hearing loss and additional symptoms, such as ear fullness, tinnitus, dizziness, or hyperacusis, were enrolled in this study. Serum samples from these patients were collected for laboratory serum autoimmunity detection, including AECAs, antinuclear antibodies, immunoglobulin, and circular immune complex. Therapeutic responses to combination therapy in short-term outcome and serum cytokine levels were compared between AECA-positive and AECA-negative patients. Anti-endothelial cell autoantibodies-positive patients tended to show significantly less response to standard therapy compared with AECAs controls (P < .05). Moreover, some serum cytokine levels elevated in both AECAs- and AECAs+ groups. Positive ratio of interleukin-8 and concentrations of macrophage inflammatory protein-1α were found higher in AECAs+ groups (P < .05). The results supported that AECAs might wield influence on the short-term outcome of acute low-tone hearing loss (ALHL) treatment. Furthermore, AECA-mediated acute low-frequency hearing loss possibly involved dysregulation of inflammation process and release of cytokines.

Live imaging and functional changes of the inner ear in an animal model of Meniere\u2019s disease

The symptoms of Meniere’s disease (MD) are generally considered to be related to endolymphatic hydrops (EH). There are many recent reports supporting the possibility that vasopressin (VP) is closely linked to the formation of EH in Meniere’s disease. Based on this, we developed a clinically relevant animal model of Meniere’s disease in which a VP type 2 receptor agonist was administered after electrocauterization of the endolymphatic sac. We report live imaging of the internal structure, and functional changes of the inner ear after electrocauterization of the endolymphatic sac and administration of a VP type 2 receptor agonist. In this model, the development of EH was visualized in vivo using optical coherence tomography, there was no rupture of Reissner’s membrane, and low-tone hearing loss and vertiginous attacks were observed. This study suggested that acute attacks are caused by the abrupt development of EH. This is the first report of live imaging of the development of EH induced by the administration of a VP type 2 receptor agonist.

THE EFFECTS OF HEARING LOSS AND MOBILITY DECLINE ON COGNITIVE FUNCTION OF OLDER ADULTS

Background: Both hearing loss and mobility decline are well-known risk factors of cognitive impairment among older adults. However, the effects of the accumulation of these functional impairments are still unclear. Thus, the present study examined whether the interactive effects of hearing loss and poor gait performance contribute to cognitive impairments. Methods: Hearing loss and gait performance were assessed in 716 community-dwelling older adults at baseline. Pure-tone audiometry was conducted to determine hearing loss at 1 (i.e., low tone) and 4 kHz (i.e., high tone). Poor gait performance was defined as the lowest quartile (fourth quartile) of age- and sex-appropriate mean gait velocity. Participants were then classified into four groups according to the presence of hearing loss and poor gait performance. Cognitive function was assessed using MMSE and MoCA at baseline and four years later. Results: Older adults who had either hearing loss (low or high tone) or poor gait performance showed lower MMSE and MoCA scores at baseline. Multiple regression models showed that hearing loss and poor gait performance at baseline were significantly associated with decreased cognitive function at follow-up. Among older adults with low tone hearing loss, absence of slow gait was not associated with decreased cognitive function. Conclusions: Our results indicate the possibility that hearing loss and slow gait synergistically increase the risk of cognitive impairment. The results also suggest that the effect of slow gait on cognition exceeds the effects of hearing loss, indicating the importance of maintaining mobility in late life.

Spontaneous intracranial hypotension with endolymphatic hydrops: A case report

Spontaneous intracranial hypotension may be defined as a postural headache syndrome without preceding major head trauma or dural puncture, associated with low cerebrospinal fluid volumes and opening pressure. Orthostatic headache is a cardinal clinical manifestation, associated symptoms may include neck stiffness, nausea, diplopia, vertigo, tinnitus and deafness in spontaneous intracranial hypotension. We describe a woman presented with a 1 week history of headache who was diagnosed with endolymphatic hydrops after cerebrospinal fluid analysis. A 40 years old woman presented with a 1 week history of headache. The pain was described as generalized non-throbbing and complain a mild febrile sensation. She admitted a local hospital but her symptoms were continued. On admission, she had severe orthostatic headache, nausea, vomiting and both ear fullness, tinnitus. No photophobia, phonophobia, and other autonomic dysfunction were exist. She had never been previous head or back trauma and cerebrospinal fluid tapping history. No abnormality in laboratory result. cerebrospinal fluid exam showed 4cmH2O pressure, RBC 780, WBC 0, glucose 39 (serum 83), protein 95. Brain MRI showed diffuse prominent dural enhancement by gadolinium. Pure tone audiogram: decreased hearing in low tone. It suggested endolymphatic hydrops. She treated by hydration and symptomatic treatment and symptoms were improved. In conclusion, a compensatory expansion of the endolymphatic compartment would induce endolymphatic hydrops and in the result, it causes low tone hearing loss. Because spontaneous intracranial hypotension may cause endolymphatic hydrops, it is highly probable that audiometry is necessary to the orthostatic hypotension patient with ear fullness.

Complex tone stimulation may induce binaural diplacusis with low-tone hearing loss.

To clarify the possible mechanism causing binaural diplacusis with low-tone hearing loss, two psychoacoustic experiments were performed with 20 healthy subjects, using harmonic complex tones. In the first experiment, two tones were presented unilaterally, either from the right or left side. One of the tones presented was higher in frequency in terms of the fundamental component, but lower or equal in frequency in terms of the highest component, than the other tone. The subjects were asked which tone was higher in pitch after listening to both tones. They were also asked to compare tones in which low-tone components were eliminated. In the second experiment, the subjects heard these complex tones binaurally, with low-tone components eliminated in one ear. In the first experiment, most subjects perceived pitch direction, that is, higher or lower, in a reverse way when low-tone components were eliminated from the complex tones. In the second experiment, approximately half of all subjects heard the tones at different pitches in both ears. Under certain conditions, complex tone stimulation may induce binaural diplacusis when low-tone hearing is lost in one ear.

In vivo Assessment of an Endolymphatic Hydrops Gradient Along the Cochlea in Patients With Menière's Disease by Magnetic Resonance Imaging-A Pilot Study.

To assess three strategies for evaluation and description of potential endolymphatic hydrops (EH) gradients along the cochlea in patients with Menière's disease. Prospective observational study. Ten patients with definite Menière's disease revealed by magnetic resonance imaging were included in this prospectively conducted pilot study. The presence of cochlear endolymphatic hydrops as well as a potential hydrops gradient along the cochlea were subjectively evaluated by two readers. Furthermore, both readers performed planimetric measurements of the relative extent of endolymphatic hydrops in the cochlear turns for calculation of an apico-basal-index (ABI) and an average gradient slope of the endolymphatic hydrops. These models were correlated with the available pure tone audiometry (PTA). Qualitatively, 13 of 16 inner ears presented an apical EH distribution. The median ABI was 1.69 for patients with low-tone hearing loss and 1.17 for patients with a flat PTA curve (p = 0.03). The median EH slope was 7.44 and correlated with the steepness of the PTA (ρ = 0.583; p = 0.018). The subjective analysis and the slope model were best fit for prediction of a low-tone hearing loss type with sensitivities of 100% (specificity, 42.86%) and 88.9% (specificity, 71.4%), respectively. The inter-reader agreement in all three approaches was considered substantial to perfect. The presented qualitative approach and the slope model represent reliable methods for the description of a potential EH gradient along the cochlea. Furthermore, the average EH steepness along the cochlea correlates with the type of hearing loss.

Comorbid Symptoms Occurring During Acute Low-Tone Hearing Loss (AHLH) as Potential Predictors of Menière's Disease.

Acute low-tone sensorineural hearing loss (ALHL) is a type of idiopathic sudden sensorineural hearing loss. ALHL is rarely a solitary condition but rather co-occurs with vertigo and tinnitus, being an element of contemporary diagnostic criteria for Menière's disease (MD). The goal of our present study was to determine the value of ALHL for the early diagnosis of MD in patients presenting in the emergency room with ALHL as a main complaint. The files of 106 patients with ALHL who were admitted to the emergency room over the period of 7 years and 104 patients with acute high- tone sensorineural hearing loss (AHHL) from the same period were included in this retrospective study. Forty ALHL patients presented with recurrent episode of hearing loss and 66 remaining patients presented with ALHL for the first time. Of the latter group, 25 patients gave consent for the follow-up. First, we analyzed the difference in the occurrence of tinnitus and vertigo between the ALHL and AHHL groups. In patients with ALHL, the incidence of vertigo with tinnitus and the number of recurrent episodes were statistically higher than in patients with AHHL. Next, we focused on the ALHL follow-up group (25 patients). In that group, two patients had all MD symptoms at presentation, 18 had ALHL and tinnitus and five ALHL only. Of 18 patients with ALHL and tinnitus at admission, five developed vertigo and thus the triad of Menière's disease. None of the five patients with AHLH as a sole symptom developed MD during the follow-up time but four of them have developed tinnitus. Patients with recurrent ALHL had significantly higher incidence of MD than the patients with first episode. We conclude that some patients who present with ALHL and concomitant tinnitus or have recurrent episodes of ALHL are more likely to develop Menière's disease than these patients, who present with ALHL as a sole symptom. Nonetheless, we recommend otological follow-up for all patients presenting with ALHL.

Clinical characteristics of sudden low-tone hearing loss

Objective:We aimed to investigate the prognosis and clinical characteristics of patients with acute low-tone sensorineural hearing loss(ALHL) and the patients with sudden low-tone loss who were not classified in the audiometric definition ALHL of(non-ALHL).Method:Two hundred and seven patients diagnosed at the university hospital with idiopathic sudden low-tone loss of sensorineural hearing loss including 48 ALHL and 159 non- ALHL from Jan 2010 to Dec 2015.The patients were followed up in the long term with three months to 5 years.The rates of recurrence and/or progression to Ménière's disease for patients with ALHL were compared with those for non-ALHL patients.Result:The recurrence rate was 26.4% for non-ALHL and 16.7% for ALHL.There was statistically significant difference between the two patient groups.In ALHL patients,8.8% patients progressed to Ménière's disease,1.9% was diagnosised with acoustic neuroma and 5.7% with vestibular migraine.In non-ALHL patients,4.2% patients progressed to Ménière's disease.Conclusion:In clinical practice,sudden low-tone loss other than ALHL shows a potential for recurrence and progressed to Ménière's disease.