Hypotension and sensorineural hearing loss: a possible correlation

Longitudinal Blood Pressure Patterns from Mid-to-Late Life and Late-life Hearing Loss in the Atherosclerosis Risk in Communities Study

BACKGROUND

Hearing loss is prevalent and associated with adverse functional outcomes in older adults. Prevention thus has far-reaching implications, yet few modifiable risk factors have been identified. Hypertension may contribute to age-related hearing loss, but epidemiologic evidence is mixed. We studied a prospective cohort of 3,343 individuals from the Atherosclerosis Risk in Communities study, aged 44-65 years at baseline with up to 30 years of follow-up.

METHODS

Hearing was assessed in late-life (2016-17) using a better-ear audiometric pure tone average (PTA, 0.5, 1, 2, 4 kHz) and the Quick Speech-in-Noise (QuickSIN) test. Hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg or antihypertensive medication use. Mid-life hypertension was defined by hypertension at two consecutive visits between 1987-89 and 1996-98. Late-life hypertension was defined in 2016-17. Late-life low blood pressure was defined as systolic blood pressure <90 mmHg or diastolic blood pressure <60 mmHg, irrespective of antihypertensive medication use. Associations between blood pressure patterns from mid-to-late-life and hearing outcomes were assessed using multivariable-adjusted linear regression.

RESULTS

Compared to persistent normotension, persistent hypertension from mid-to-late-life was associated with worse central auditory processing (difference in QuickSIN score = -0.66 points, 95% CI: -1.14, -0.17) but not with audiometric hearing.

CONCLUSIONS

Participants with persistent hypertension had poorer late-life central auditory processing. These findings suggest that hypertension may be more strongly related to hearing-related changes in the brain than in the cochlea.

Treatment for hypotension in the first 24 postnatal hours and the risk of hearing loss among extremely low birth weight infants

OBJECTIVE

To evaluate whether treated hypotension in the first 24 postnatal hours is associated with hearing loss in extremely low birth weight (ELBW) infants.

STUDY DESIGN

In a cohort of 735 ELBW infants, we identified 25 with sensorineural hearing loss (SNHL) at 12-24 months adjusted age. For each case, we selected three controls with normal hearing. Logistic regression models were used to adjust for confounding variables.

RESULTS

Sixty percent of cases and 25% of controls were treated for hypotension. After adjusting for confounding variables (gestational age, antenatal glucocorticoids, 5 min Apgar < 6, insertion of an umbilical catheter, treatment with high frequency ventilation, and major cranial ultrasound abnormality), treated hypotension was associated with an increased risk of SNHL (adjusted odds ratio: 3.6; 95% confidence interval: 1.3-9.7).

CONCLUSIONS

Treated hypotension in ELBW infants in the first 24 h of life is associated with an increased risk of SNHL.

Analysis of Clinical and Laboratory Findings of Idiopathic Sudden Sensorineural Hearing Loss

Idiopathic sudden sensorineural hearing loss (ISSNHL) is an emergency disease requiring immediate diagnosis and treatment. The incidence of ISSNHL in the Western countries’ population was estimated to 5–20 per 100,000 inhabitants. The etiology of ISSNHL remains unknown. Its pathogenesis is most often suggested to be due to a disturbed microcirculation and infection. Previous studies have reported that comorbidities, including hypertension, diabetes mellitus (DM), and hyperfibrinogenemia are risk factors of ISSNHL. This study aimed at investigating the clinical characteristics, laboratory parameters and comorbidities of patients with ISSNHL. Our study suggests that the annual incidence of ISSNHL in China mainland is 19 per 100 000. The clinical characteristics and prevalence of comorbidities of ISSNHL patients are different according to age distribution and hearing results. Moreover, the patients with vertigo, hypertension, DM and high TG suffered more often from severe hearing loss compared with the counterparts. This indicates that the cardiovascular and metabolic diseases (hypertension and hyperlipidemia) appeared to be closely associated with the occurrence and severity of ISSNHL.

Effects of Dexmedetomidine Infusion During Sevoflurane Anesthesia on Otoacoustic Emissions

Background and Objectives

Knowing the ototoxic potential of the agents used in medical treatments is important for the protection of hearing. Although we have knowledge regarding some effects of dexmedetomidine, which is an anesthetic-sparing drug, its influence over the hearing system has never been studied and is obscure yet. The aim of this study is to determine the effects of intravenous dexmedetomidine application during sevoflurane anesthesia on otoacoustic emissions (OAEs).

Subjects and Methods

This prospective randomized study was performed on 60 patients (34 male, 26 female, mean age: 30.6±9.2 years) who were scheduled for an elective surgery under general anesthesia and the patients were enrolled and randomly divided into 2 groups. They received dexmedetomidine (Group D) or Saline (Group S) infusion during a standardized Sevoflurane anesthesia. Transient and distortion product OAEs were measured preoperatively and postoperatively (24th hour). OAE results were compared within and between groups.

Results

In group D postoperative OAEs were lower than preoperative OAEs and postoperative levels of group S, especially at low frequencies (p<0.05).

Conclusions

Dexmedetomidine infusion affects the micromechanical function of cochlea especially in the low-frequency region. Dexmedetomidine should be carefully used during general anesthesia to avoid its probable harmful effects on cochlear micromechanics.

Primary vascular dysregulation syndrome: Possible implications for inner ear acute diseases?

Primary vascular dysregulation syndrome has been reported as a possible cause for different eye diseases. Signs or symptoms of this syndrome not only may consist in a series of ocular disorders, as they possibly concern or are associated to various systemic conditions; even the damage of another terminal sensory organ as the inner ear is reported among the possible associations. Herein, the analogies between eye and inner ear are outlined, analyzing the PVD profile that well corresponds to our widely described model of subject without organic cardiovascular impairment but prone to inner ear acute disturbances. Actually, in absence of a recognized cause the latter can be due to a systemic dysregulation like the described one concerning ocular disorders.

A case of heroin induced sensorineural hearing loss

A case of a 31-year-old male who developed profound sensorineural hearing loss following a heroin overdose is presented. The patient subsequently had a full recovery of his hearing. Other cases of this rare phenomenon are reviewed and management options are discussed.

White matter hyperintensities predict low frequency hearing in older adults

Vascular disease has been proposed as a contributing factor for presbyacusis (age-related hearing loss). While this hypothesis is supported by pathological evidence of vascular decline in post-mortem human and animal studies, evidence in human subjects has been mixed with associations typically reported between a measure of vascular health and low frequency hearing in older women. Given the difficulty of characterizing the in vivo health of the cochlear artery in humans, an estimate of cerebral small vessel disease was used to test the prediction that age-related change in low frequency hearing and not high frequency hearing is related to a global decline in vascular health. We examined the extent to which these associations were specific to women and influenced by a history of high blood pressure in 72 older adults (mean age 67.12 years, SD = 8.79). Probability estimates of periventricular white matter hyperintensities (WMH) from T1- and fluid attenuated T2-weighted magnetic resonance images were significantly associated with a low frequency hearing metric across the sample, which were independent of age, but driven by women and people with a history of high blood pressure. These results support the premise that vascular declines are one mechanism underlying age-related changes in low frequency hearing.

Diuretics in Meniere disease: a therapy or a potential cause of harm?

Despite the lack of clear evidence for their effectiveness in treating vertigo, tinnitus, hearing loss and aural fullness, diuretics, represent a common treatment for Meniere disease (MD), as they are supposed to decrease volume and pressure in the endolymphatic partition of the labyrinth. Our group have outlined the possibility of an adverse effect on inner ear function derived from an abrupt lowering of blood pressure: a subsequent exaggerated vasomotor response inducing local ischemia could be responsible for more or less permanent damage. The inner ear, owing both to its terminal vascular supply and to the necessity of a steady metabolism, seems a reliable target for any hemodynamic imbalance that acutely affect its perfusion. In our opinion, the complexity of the inner ear anatomy and function argues against the usefulness of diuretics to reduce endolymphatic volume, in analogy to their effect on the volemia: too many active mechanisms and "buffer" systems are involved in the labyrinth. Even considering that the finding of mean low pressure values is relatively common in subjects with MD, an attempt should be to maintain a stable blood perfusion to the labyrinth; in fact, an abrupt decrease in systemic blood pressure can trigger an adverse sympathetic reaction and transmit misleading information to the cochlear vasopressin receptors.

Tinnitus in elderly patients and prognosis of mild-to-moderate congestive heart failure: a cross-sectional study with a long-term extension of the clinical follow-up

BACKGROUND

The complex mechanism responsible for tinnitus, a symptom highly prevalent in elderly patients, could involve an impaired control of the microcirculation of the inner ear, particularly in patients with poor blood pressure control and impaired left ventricular (LV) function.

METHODS

In order to define the relationship between the presence of tinnitus and the severity and clinical prognosis of mild-to-moderate chronic heart failure (CHF) in a large population of elderly patients (N = 958), a cross-sectional study was conducted with a long-term extension of the clinical follow-up. Blood pressure, echocardiographic parameters, brain natriuretic peptide (BNP), hospitalization, and mortality for CHF were measured. Multivariate logistic regression analysis was used to assess the association between the presence of tinnitus and some of the prognostic determinants of heart failure.

RESULTS

The presence of tinnitus was ascertained in 233 patients (24.3%; mean age 74.9 ± 6 years) and was associated with reduced systolic and diastolic blood pressure (123.1 ± 16/67.8 ± 9 vs 125.9 ± 15/69.7 ± 9; P = .027/P = .006), reduced LV ejection fraction (LVEF%; 43.6 ± 15 vs 47.9 ± 14%, P = .001), and increased BNP plasma levels (413.1 ± 480 vs 286.2 ± 357, P = .013) in comparison to patients without symptoms. The distribution of CHF functional class was shifted toward a greater severity of the disease in patients with tinnitus. Combined one-year mortality and hospitalization for CHF (events/year) was 1.43 ± 0.2 in patients with tinnitus and 0.83 ± 0.1 in patients without tinnitus, with an adjusted hazard ratio (HR) of 0.61 (95% confidence interval (CI): 0.37 to 0.93, P <.002).

CONCLUSIONS

Our preliminary data indirectly support the hypothesis that tinnitus is associated with a worse CHF control in elderly patients and can have some important clinical implications for the early identification of patients who deserve a more aggressive management of CHF.

Meniere's disease: update of etiopathogenetic theories and proposal of a possible model of explanation

Meniere's Disease (MD) is an affection consisting of an association of sensorineural hearing loss, tinnitus and vertigo initially presenting by crises. A review of the most considered possible causative factors and pathophysiologic interpretations allows us to underline the uncertainties which still exist about the genesis of this illness. We propose a mechanistic model based on the effect of a haemodynamic imbalance leading to transient ischaemia which could have an effect on the pH of the inner ear as well as on the work of the inner ear proton pumps. It is hypothesized that under ischaemic conditions and consequent metabolic acidity a preserved proton pump activity can generate an overload of anions in the endolymphatic partition, which is a closed system, thus resulting in an enhancement of osmolarity and consequently in the formation of a hydrops resulting in the development of fluctuating hearing loss, tinnitus and vertigo which characterize Meniere's Disease.

Sensorineural hearing loss and celiac disease: a coincidental finding

BACKGROUND

Celiac disease (CD) can be associated with a variety of extraintestinal manifestations, including neurological diseases. A new neurological correlation has been found between CD and sensorineural hearing loss (SNHL).

OBJECTIVE

To verify the association between SNHL and CD, and to establish whether the neurological hearing impairment in CD is related to nonorgan-specific and antineuronal antibodies, as well as the presence of autoimmune disorders.

METHODS

A sample of 59 consecutive biopsy- and serologically proven CD patients were studied. Among CD patients, 11 were newly diagnosed and 48 were on a gluten-free diet. Hearing function was assessed by audiometric analysis in all CD patients as well as in 59 age- and sex-matched controls. Patients were tested for a panel of immune markers including nonorgan-specific autoantibodies and antineuronal antibodies.

RESULTS

SNHL was detected in five CD patients (8.5%) and in two controls (3.4%). In one patient, the SNHL was bilateral, whereas the remaining four had a monolateral impairment. The prevalence of SNHL was not significantly different between CD patients and controls. At least one of the antibodies tested for was positive in two of the five CD patients with SNHL and in 12 of the 54 CD patients without SNHL. Antineuronal antibodies to central nervous system antigens were consistently negative in the five CD patients with SNHL. Only one of the five CD patients with SNHL had Hashimoto thyroiditis.

CONCLUSIONS

SNHL and CD occur coincidentally. Hearing function should be assessed only in CD patients with clinical signs of hearing deficiency.

Antihypertensive Drug and Inner Ear Perfusion: An Otologist's Point of View

A number of labyrinthine disorders with sensorineural hearing loss, vertigo, and tinnitus are known to occur to young people without vascular risk factors, thus being classified as "idiopathic" in the absence of satisfactory explanations; in the last decade, this phenomenon has found a reliable explanation by the adverse effect of a sharp decrease of blood pressure values followed by an abnormal vasomotor regulation. This model may not only be applied to healthy subjects, but even had some confirmation in conditions possibly affecting hemodynamic changes, such as heart failure or treated hypertension. In particular, the results of a recent study on the impact of different antihypertensive therapies, which was analyzed by monitoring the onset or enhancement of tinnitus as a symptom of inner ear sufferance, unequivocally demonstrated an increased prevalence of tinnitus in subjects submitted to more "aggressive" treatments. This seems in agreement with recent observations about the model of fluid homeostasis of the inner ear, and suggests, when possible, to resort to treatments with modulatory effects in order to maintain a steady perfusion to the labyrinth thus protecting its function.

Could echocardiography yield a cardiovascular profile of the tinnitus prone subject?

The possible genesis of some damage of the inner ear from a hemodynamic imbalance of functional origin, possibly linked to hypotension followed by an abnormal vasomotor regulatory activity, has been pointed out by our group over the years. As tinnitus, which is often referable to an inner ear origin, can represent a signal of incoming sufferance of the organ of Corti and may not necessarily be linked to hearing impairment, it seemed of some utility to investigate on the prevalence of tinnitus under various well monitored hemodynamic conditions. This led to observe that the prevalence of this symptom, regardless of audiological features, was increased under "aggressive" antihypertensive therapy as well as in particularly severe degree of heart decompensation. These data represent a first step and encourage in searching for a profile of subject who could be more prone to the development of tinnitus with respect to the normal population, even in absence of pathological conditions. With this aim, echocardiography is thought to be able to yield useful informations in addition to standard and ambulatory blood pressure monitoring, in order to obtain a better definition of the correlations between cardiovascular function (and related changes) and inner ear insufficient perfusion.

Clinical investigation on hypotensive patients with vertigo

The aim of this study was to investigate the characteristic of hypotensive patients with vertigo. Twenty hypotensive patients with rotatory vertigo, 15 hypotensive subjects without vertigo, and 15 mitral valve prolapse subjects without vertigo underwent a battery of tests including audiometry, electronystagmography (ENG), and vestibular evoked myogenic potential (VEMP) test. The abnormal rates in terms of audiometry, eye tracking, optokinetic nystagmus, visual suppression, and caloric tests were 15, 35, 35, 10, and 42% for the first group; 13, 20, 33, 0, and 0% for the second group; and 7, 13, 60, 0, and 3% for the third group, respectively. Comparison of the first group with the other two control groups revealed that significant difference existed only in the abnormality of caloric responses. Fifteen (75%) of 20 hypotensive patients with vertigo having abnormal ENG results, asymmetric caloric responses, or delayed VEMPs were attributed to vertigo of central origin, possibly from ischemic disorder. In contrast, five patients (25%) had neither central signs in ENG nor abnormal VEMPs, but showing bilateral normal or hyperactive caloric responses were classified as autonomic dysfunction. After 3 months of medication, all patients with autonomic dysfunction had their vertigo and autonomic symptoms subsided, whereas 27% of the patients with ischemic disorder had vertigo persisted, showing a significant difference. In conclusion, hypotensive patients with vertigo could be due to either direct autonomic dysfunction or ischemic disorder mediated by autonomic deficits.

Is there a role for atrial peptides in the labyrinthine “disease”?

The important role of atrial natriuretic peptides (ANP) in regulating blood pressure and changing vascular permeability has been widely studied and assessed during the last ten years. Considering the characteristics of this mechanism, which is responsible for a hypotensive and hypovolemic effect, and the possible role of hypotension associated with a default of autoregulatory sympathetic reactions in inner ear unexplained disorders, it seems reasonable to hypothesize a possible involvement of ANP system in the genesis of such disorders. As a matter of fact, the presence of specific receptors for ANP in the inner ear has been widely reported in studies concerning both rat and human inner ear, although their precise role in the labyrinthine homeostasis has not been satisfactory explained until now. Some aspects concerning vascular and fluid regulation of the inner ear under different conditions still remain not totally clear, and consequently a detailed explanation to the possible mechanism causing inner ear disorders of functional origin is lacking; from this point of view, an investigation on the serum level of ANP in subjects with labyrinthine affections of uncertain origin could be of some utility in contributing to assess the role of this system in the inner ear fluid regulation and in the inner ear perfusion and to investigate on the possible influence of an abnormal ANP release in some kind of inner ear damage.

Is tinnitus useful in early detection of incoming heart decompensation?

In previous studies the possibility of a mechanism of hemodynamic imbalance consequent to a sharp decrease in blood pressure causing a more or less transient inner ear impairment was evaluated and to some extent demonstrated. In this scenario, tinnitus is very frequently present as a debilitating symptom associated to cochlear impairment. On the other hand, a possible cause of a sharp decrease in blood pressure is represented by major cardiovascular disorders, requiring an early assessment in order to avoid fatal consequences. In this paper, the hypothesis of resorting to tinnitus as a simple warning method for self detecting a possibly incoming cardiovascular imbalance in patients with heart failure (HF) is advanced.

Possible role of HMG-CoA reductase inhibitors for the treatment of sudden sensorineural hearing loss (SSHL)

The term 'idiopathic' is used to design sudden sensorineural hearing loss when causative factors cannot be identified. In most cases a viral infection or a circulatory defect are considered to play a significant role when an alternative satisfactory explanation cannot be found. However some significant points remain unclear, since the great variability in age and general conditions of the affected people makes it difficult to find a reliable interpretation of the exact nature of this phenomenon which is reasonably considered to have a multifactorial origin. Under these conditions many different therapeutic strategies have been put forward, thus suggesting some degree of uncertainty not only about the pathogenetic mechanisms of the disease but also on the actual effectiveness of the disparate treatment approaches. In this paper the use of statins in sudden sensorineural hearing loss is firstly proposed on the basis of their metabolic and hemodynamic effects, and the possible clinical implications are outlined.

Modulation of presbycusis: current status and future directions

Literature and ideas are reviewed concerning the modulation of presbycusis - the influence of variables that can alter the severity and/or time course of presbycusis or counteract its negative aspects. Eleven topics are identified: variables related to biological aging; genetics; noise-induced hearing loss; moderately augmented acoustic environment; neural plasticity and the central auditory system; neural plasticity and hearing aids; socioeconomic and cultural barriers to hearing aid use; lifestyle (diet, exercise, etc.); medical variables; pharmaceutical interventions for presbycusis, and cognitive variables. It is concluded that the field of otogerontology will best be served by a comprehensive, integrative interaction among basic researchers and clinical scientists who will continue to learn how the auditory problems associated with presbycusis can be intentionally modulated in beneficial ways.