Sudden Sensorineural Hearing Loss

Cerebral Small Vessel Disease in Elderly Patients with Sudden Sensorineural Hearing Loss

BACKGROUND

The cause of sudden sensorineural hearing loss (SSNHL) is uncertain in a significant number of patients. A vascular etiology has been proposed because SSNHL increases the risk of developing a stroke. Cardiovascular risk factors can cause cerebral small vessel disease (CSVD). The presence of CSVD in turn raises the risk of stroke.

AIM

The aim of this study was to compare the presence of CSVD and cardiovascular risk factors in elderly patients with idiopathic SSNHL (iSSNHL) to a control cohort.

METHOD

Patients with iSSNHL of 50 years and older were compared with a control cohort with patients suspected of trigeminal neuralgia or vestibular paroxysmia. The primary outcome was the difference in the number of white matter hyperintensities using the ordinal Fazekas scale. Secondary outcomes were the presence of brain infarctions on MRI and the difference in cardiovascular risk factors.

RESULTS

In the SSNHL cohort, Fazekas score 2 was most frequently seen compared with Fazekas 1 in the control cohort. The distribution of Fazekas scores did not differ significantly. The sum of the Fazekas scores were 13,925 and 14,042 for iSSNHL and controls, respectively ( p = 0.908). Brain infarctions were seen in 8 patients with iSSNHL (n = 118) and in 13 patients in the control cohort (n = 118) ( p = 0.361). None of the cardiovascular risk factors were more frequently seen in the iSSNHL cohort.

CONCLUSION

Patients with iSSNHL did not exhibit more CSVD on MRI than controls. This result is in contrast with previous literature demonstrating a higher risk of stroke in patients with iSSNHL than in controls. A prospective analysis with a larger study population is therefore warranted.

Anatomical location of AICA loop in CPA as a prognostic factor for ISSNHL

The cerebellopontine angle (CPA) is a triangular-shaped space that lies at the junction of the pons and cerebellum. It contains cranial nerves and the anterior inferior cerebellar artery (AICA). The anatomical shape and location of the AICA is variable within the CPA and internal auditory canal (IAC). A possible etiology of idiopathic sudden sensorineural hearing loss (ISSNHL) is ischemia of the labyrinthine artery, which is a branch of the AICA. As such, the position of the AICA within the CPA and IAC may be related to the clinical development of ISSNHL. We adopted two methods to classify the anatomic position of the AICA, then analyzed whether these classifications affected the clinical features and prognosis of ISSNHL. We retrospectively reviewed patient data from January 2015 to March 2018. Two established classification methods designed by Cahvada and Gorrie et al. were used. Pure tone threshold at four different frequencies (0.5, 1, 4, and 8 kHz), at two different time points (at initial presentation and three months after treatment), were analyzed. We compared the affected and unaffected ears, and investigated whether there were any differences in hearing recovery and symptoms between the two classification types. There was no difference in AICA types between ears with and without ISSNHL. Patients who had combined symptoms such as tinnitus and vertigo did not show a different AICA distribution compared with patients who did not. There were differences in quantitative hearing improvement between AICA types, although without statistic significance (p = 0.09–0.13). At two frequencies, 1 and 4 kHz, there were differences in Chavda types between hearing improvement and no improvement (p < 0.05). Anatomical variances of the AICA loop position did not affect the incidence of ISSNHL or co-morbid symptoms including tinnitus and vertigo. In contrast, comparisons of hearing improvement based on Chavda type classification showed a statistical difference, with a higher proportion of Chavda type 1 showing improvements in hearing (AICA outside IAC).

The role of allergy in the etiopathogenesis of idiopathic sudden sensorineural hearing loss

To evaluate the role of allergy in the etiopathogenesis of sudden hearing loss using cytokine profile, allergic parameters, and lymphocyte subgroups, a total of 31 patients aged between 30 and 62 years (mean age: 42.48 ± 15.86 years) with the diagnosis of sudden hearing loss were enrolled in the study between 2008 and 2011. The control group comprised 30 age-matched adult subjects accepted as clinically healthy individuals living in the same region with comparable socioeconomic parameters. The patient and the control group were questioned for history of allergy. Lymphocyte subgroups in the peripheral blood were evaluated using Becton-Dickinson monoclonal CD4, CD8, CD19, and CD23 antibodies. In the patient and control groups, the levels of IFN- γ, IL4, IL10, and total IgE were measured and compared between the groups. Skin test was used for detection of inhaler allergens in the patient and the control groups, and specific IgE tests were performed using the RAST method for food allergens. The Spearman's rho correlation, the unpaired t test, the Mann-Whitney U test, and the Shapiro-Wilk test were used to determine the differences between the groups. The limit for statistical significance was p < 0.05. When the patient and the control group were compared, the differences between CD4, CD23, IL4, IL10, and IgE were statistically significant. On analyses of the patients' serum samples, strongly positive correlations were determined between IgE and CD23, IL10, IL4; IL4 and IL10, CD23, CD4; IL10 and CD23, CD4 (Spearman rho, p = 0.000), while a weakly positive correlation was found between IgE and CD4 (Spearman rho, p = 0.020). A correlation between IFN-γ and CD4 was weakly negative (Spearman rho, p = 0.040). The total IgE levels were estimated to be above the normal reference ranges (0-100 IU/ml) in 25.8 % of the cases in the patient group. History of allergy was found in 61.9 % of the patients. The results of this study substantiate the role of allergy in the etiopathogenesis of sudden hearing loss. We think that during the diagnostic work-up of these patients allergy should be interrogated seriously, necessary tests should be performed, and allergy should be considered in the decision-making process of the treatment of sudden hearing loss.

Sudden sensorineural hearing loss: an otologic emergency

The study purpose was to determine the efficacy of steroids, volume expanders and antivirals in the management of idiopathic sudden sensory neural hearing loss and to establish importance of early medical intervention. In this prospective study, thirty-four patients presenting with idiopathic sudden hearing loss of 30 db or more were enrolled in study group between 2005 and 2009. Patient variables as they related to recovery were studied and include patient age, time to onset of therapy, status of contralateral ear, presence of diabetes, severity of hearing loss, pattern of hearing loss in audiogram and presence of associated symptoms, (tinnitus, vertigo). Treatment protocol with intravenous hydrocortisone, intravenous dextran and oral anti-viral agent was followed. Pre-treatment and post-treatment pure tone average was analyzed. With combination therapy the overall improvement in pure tone threshold was seen in 27 patients (79.4%). A statistically significant association was found between the time at which medical intervention was started and hearing improvement. Early intervention in patients presenting before 3 days has given 77.8% complete type 1 recovery Idiopathic sudden sensory neural hearing loss is a medical emergency. It should not be misdiagnosed. Early detection and management with volume expanders, steroids and antivirals will improve the chances of complete recovery.

Weather conditions and sudden sensorineural hearing loss

BACKGROUND: Climatic or meteorological condition changes have been implicated in the pathogenesis of Idiopathic Sudden Sensorineural Hearing Loss (ISSHL). We investigated the seasonal distribution of ISSHL and evaluated the influence of meteorological parameters (such as temperature, humidity, and atmospheric pressure), their variation and covariation on the incidence of the disease. METHODS: A total of 82 cases of ISSHL, admitted to our department over a five-year period, were enrolled in the study. Seasonal distribution of the disease was investigated by dividing the year in four seasons. Meteorological data included daily values of 13 distinct parameters recorded at the meteorological station of the University of Ioannina during this period. A relationship between each meteorological variable and the incidence of ISSHL was investigated by applying (chi2) test on data from 13 contingency tables as well as by using logistic regression and t-test approaches. In addition, the influence of different weather types on the incidence of ISSHL was investigated using Cluster Analysis in order to create eight clusters (weather types) characteristic for the prefecture of Ioannina. RESULTS: The results of the study could not indicate any seasonal distribution of the disease. The incidence of ISSHL could not be significantly correlated either to any distinct meteorological parameter or to any specific weather type. CONCLUSIONS: Meteorological conditions, such as those dominating in the Northwestern Greece, and/or their changes, have no proven effect on the incidence of ISSHL.

'Farmer's ear': sudden sensorineural hearing loss due to Chlamydia psittaci infection

A case of sudden sensorineural hearing loss in association with a Chlamydia psittaci pneumonia is reported. Rapid recovery was seen when the patient was treated with high dose steroids and appropriate antibiotics. This is the first such case report in the literature.