Sudden Sensorineural Hearing Loss after Rapid Reduction of Blood Pressure in Malignant Hypertension

Extracellular ATP accelerates cell death and decreases tight junction protein ZO-1 in hypoxic cochlear strial marginal cells in neonatal rats

In the cochlear, extracellular ATP (eATP) plays an important role in both physiological and pathological processes, but its role in the hypoxic cochlear remains unclear. The present study aims to investigate the relationship between eATP and hypoxic marginal cells (MCs) in the stria vascularis in cochlear. Combining various methodologies, we found that eATP accelerates cell death and decreases tight junction protein zonula occludens-1 (ZO-1) in hypoxic MCs. Flow cytometry and western blot analyses revealed an increase in apoptosis levels and suppression of autophagy, indicating that eATP causes additional cell death by increasing the apoptosis of hypoxic MCs. Given that autophagy inhibits apoptosis to protect MCs under hypoxia, apoptosis is probably enchanced by suppressing autophagy. Interleukin-33(IL-33)/suppression of tumorigenicity-2(ST-2)/matrix metalloprotein 9(MMP9) pathway activation was also observed during the process. Further experiments involving the use of additional IL-33 protein and an MMP9 inhibitor indicated that this pathway is responsible for the damage to the ZO-1 protein in hypoxic MCs. Our study revealed the adverse effect of eATP on the survival and ZO-1 protein expression of hypoxic MCs, as well as the underlying mechanism.

Butylphthalide enhances recovery from sudden deafness

OBJECTIVES

Cochlear microcirculation disturbance caused by vasculopathy is a common cause of sudden deafness (SD). Reactive oxygen species (ROS) plays an important role in cochlear injury during ischemia-reperfusion. Butylphthalide can improve microcirculation, reduce ROS formation and inhibit apoptosis. The aim of this study was to investigate the therapeutic effect of butylphthalide on patients with SD.

PATIENTS AND METHODS

The hearing gains from 32 ears treated with butylphthalide were compared with that of 32 ears treated with non-butylphthalide. Butylphthalide capsules was administrated orally on an empty stomach for 10 continuous days. There were no significant differences in audiological and clinical data between butylphthalide and non-butylphthalide groups.

RESULTS

The hearing gain of butylphthalide group at 500, 1000, 2000, and 4000 Hz was significantly higher than that of non-butylphthalide group correspondingly (P<0.01). And, the hearing gain at PTA (pure-tone average of 500, 1000, 2000, and 4000 Hz) in butylphthalide group was significantly higher than that of non-butylphthalide group (P<0.01).

CONCLUSION

The recovery of hearing in butylphthalide group was significantly better than that of non-butylphthalide group. It is confirmed that butylphthalide has a definite therapeutic effect on SD.

Efficacy of the additional effect of hyperbaric oxygen therapy in combination of systemic steroid and prostaglandin E1 for idiopathic sudden sensorineural hearing loss

PURPOSE

The efficacies of hyperbaric oxygen therapy (HBO), systemic steroid, prostaglandin E₁, or the combination of any two modalities have been reported in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). However, little is known about the combined efficacy of HBO, systemic steroid, and prostaglandin E₁ for this disorder. We aimed to investigate the efficacy of HBO combined with systemic steroids and prostaglandin E₁ as triple therapy in patients with ISSNHL.

MATERIALS AND METHODS

We retrospectively evaluated the records of 67 patients with ISSNHL who were treated with systemic steroid and prostaglandin E₁, with (n = 38) or without (n = 29) HBO. The inclusion criteria included a diagnosis of ISSNHL within 14 days of symptom onset, age ≥15 years, treatment according to the protocol, and clinical follow-up of at least 1 month. The patients' hearing levels were evaluated 1 month after hearing loss onset. The primary outcome was hearing improvement on pure tone audiometry. We also evaluated the demographic profiles of patients.

RESULTS

Patients treated with triple therapy showed significantly greater hearing improvement (p < 0.01) than those treated without HBO, despite some differences between the two treatment groups. Multivariate logistic regression analysis revealed a significant positive correlation between pure tone audiometry improvement and hyperbaric oxygen therapy, after adjustment for confounding factors (odds ratio = 7.42; 95% and confidence interval = 2.37-23.3; p = 0.001).

CONCLUSION

HBO with systemic steroid and prostaglandin E₁ administration conferred significant therapeutic benefits for ISSNHL. Therefore, routine use of triple therapy is recommended for patients with ISSNHL.

The prevalence of hearing impairment within the Cape Town Metropolitan area

BACKGROUND

There is a lack of data on the prevalence of hearing impairment in South Africa. Current data is unreliable as it is based on national census information which tends to underestimate the prevalence of hearing impairment.

AIM

The aim of this study was to estimate the prevalence of hearing impairment in the Cape Town Metropolitan area and to determine factors associated with hearing impairment.

METHOD

A cross-sectional household survey involving 2494 partcipants from 718 households was conducted between the months of February and October 2013. Random cluster sampling was used to select four health sub-districts from eight health sub-districts in the Cape Town Metropolitan area using a method of probability proportional to size (PPS). The survey was conducted according to the World Health Organization (WHO) Ear and Hearing Disorders Survey Protocol and the classifcation of hearing impairment matched the WHO's criteria for the grading of hearing impairment.

RESULTS

The overall prevalence of hearing impairment in the population of this study was 12.35% (95%CI: 11.06% - 13.64%) and prevalence of disabling hearing impairment was 4.57% (95% CI: 3.75% - 5.39%) amongst individuals ≥ 4 years old. The following factors were found to be associated with hearing impairment; male gender, age, hypertension, a history of head and neck trauma and a family history of hearing impairment.

CONCLUSION

Based on the data from communities surveyed during this study, hearing impairment is more prevalent than previously estimated based on national population census information. Interventions for the prevention of hearing impairment in these communities should focus on individuals with associated risk factors.

Prevalence of tinnitus in patients withhypertension and the impact of different anti hypertensive drugs on the incidence of tinnitus: A prospective, single-blind, observational study

BACKGROUND

Tinnitus is a common symptom in audiology and neurologypatients. Controversial data have been reported in the literature about the prevalence of tinnitus in hypertensive patients, whereas its relationship with the extent of blood pressure (BP) control has not been substantially explored.

OBJECTIVE

The aim of this study was to determine the prevalence of tinnitus in hypertensive patients, and the impact of different antihypertensive drugs on the incidence of tinnitus in these patients.

METHODS

This prospective, single-blind, observational study was conducted at the Hypertension Clinic, St. Orsola-Malpighi Hospital, Bologna, Italy. Patients aged 18 to 75 years with uncontrolled hypertension and receiving antihypertensive therapy were enrolled. Patients were asked to complete a standardized questionnaire to assess the presence, frequency, and duration of tinnitus and the apparent effect of their antihypertensive treatment on it. Patients considered by the investigator to have tinnitus, regardless of their audiologic condition, underwent a complete clinical cardiovascular examination, including supine systolic BP (SBP) and diastolic BP measurement and standard 12-lead electrocardiography. Twelve-hour ambulatory BP monitoring was also performed, and patients were asked to record, using patient diaries, times of the onset and resolution of tinnitus that occurred during those 12 hours. From these data, correlations between the onset of tinnitus and BP were calculated.

RESULTS

A total of 476 patients participated in the study (283 men, 193 women). Of these, 84 (17.6%) patients reported occasional or prolonged spontaneous tinnitus, whereas 392 (82.4%) reported no tinnitus. The incidence of tinnitus was significantly higher in patients receiving diuretics (72/265 [27.2%]) compared with those receiving angiotensin lI receptor blockers (5/37 [13.5%]), α-blockers (12/55 [21.8%]), or 3-hydroxy-3-methylglutaryl coenzyme A reduc tase inhibitors (9/73 [12.3%]) (all, P < 0.05). Mean (SD) SBP was significantly higher in patients without tinnitus compared with those with it (143.2 [11.1 ] vs 140.6 [10.3] mm Hg; P < 0.005). In 10 (11.9%) patients with tinnitus, the onset was correlated with a sudden decrease in SBP (<140 mm Hg).

CONCLUSIONS

In this study of tinnitus in patients receiving antihypertensivetherapy, tinnitus was found in 17.6% of patients. Tinnitus was associated with the use of diuretics and with low SBP. Further studies are needed.

Bilateral sudden sensorineural hearing loss: review

Introduction:

Unilateral and bilateral sudden sensorineural hearing loss represent different disease entities. The unilateral condition is more common and predominantly idiopathic, and up to 65 per cent of patients spontaneously recover hearing. Conversely, the bilateral condition is rare, mostly associated with serious systemic conditions, and has a higher prevalence of morbidity and mortality.

Methods:

A literature search using the PubMed database was conducted using the MeSH terms ‘sudden’, ‘bilateral’ and ‘sensorineural hearing loss’.

Results:

One hundred and three reported cases of bilateral sudden sensorineural hearing loss were identified. The condition is most often associated with toxic, autoimmune, neoplastic and vascular conditions. A younger age of onset, with a bimodal age distribution, was seen for bilateral sudden sensorineural hearing loss, compared with the unilateral condition. Patients with the bilateral condition had more profound hearing loss, with poorer recovery and a 35 per cent mortality rate. Vestibular symptoms were also less common than in the unilateral condition.

Conclusion:

The presentation of bilateral sudden onset sensorineural hearing loss is a medical emergency requiring thorough and urgent investigation to exclude life-threatening and reversible conditions.

Radix astragali injection enhances recovery from sudden deafness

OBJECTIVES

An acute interruption of the blood supply to the inner ear is one of the most likely causative factors for sudden deafness (SD). Reactive oxygen species (ROS) have been suggested to be important mediators of the tissue injury during cochlear ischemia and reperfusion. Radix astragali (RA) is natural antioxidant. The aim of this study was to investigate the efficacy of RA in patients with SD.

PATIENTS AND METHODS

We compared the hearing gains from hearing impairment in 46 ears treated with RA with 46 ears treated with non-RA. RA was given intravenously daily for 10 days. There were no significant differences in clinical or audiological data between RA and non-RA groups.

RESULTS

The hearing gain at 250, 500, 1000, 2000, and 4000 Hz in RA group was much higher than that of non-RA group correspondingly (P < .01). Also, the hearing gain at PTA (pure-tone average of 250, 500, 1000, 2000, and 4000 Hz) in RA group was significantly higher than that of non-RA group (P < .01).

CONCLUSION

The recovery of hearing was significantly better after treatment of RA than non-treatment of RA. RA can be valuable concurrent therapy for patients with SD.

Hyperbaric oxygen therapy with short duration intratympanic steroid therapy for sudden hearing loss

CONCLUSION

The excellent tolerability of intratympanic (IT) steroid offers the possibility to use a high dose, which would appear to be more effective than intravenous (IV) steroid treatment, when both are associated with hyperbaric oxygen (HBO) therapy.

OBJECTIVE

The purpose of the study was to assess for the first time the efficacy of the association of IT steroid and HBO therapy in patients presenting idiopathic sudden sensorineural hearing loss (ISSNHL), comparing this protocol with another consisting of IV steroid administration and HBO therapy.

METHODS

A total of 48 patients presenting ISSNHL were recruited. Patients were divided into two categories: the severe ISSNHL group with a pure-tone average (PTA) between 70 and 90 dB, and the profound ISSNHL group with a PTA >90 dB. The first protocol consisted of 10 days of HBO therapy together with IV methylprednisolone 1 mg/kg body weight for 7 days; the second protocol consisted of HBO therapy for 10 days, associated with an IT injection of prednisolone at a dose of 62.5 mg/ml, once a day for 3 consecutive days, performed 2 h before the HBO therapy.

RESULTS

The overall success rate was superior in the group submitted to IT steroid and HBO therapy. Nevertheless, these clinical results were not statistically significant.

Transient ischemia/hypoxia enhances gentamicin ototoxicity via caspase-dependent cell death pathway

Aminoglycoside ototoxicity is a common cause of drug-induced hearing loss. Toxicity is dose related, but some patients may still develop hearing loss even under safe dosage. Apart for genetic idiosyncrasy, indirect evidences imply that ischemia may increase the aminoglycoside ototoxic sensitivity because common clinical situations associated with cochlear ischemia such as noise, sepsis, and shock are known to augment the development of aminoglycoside ototoxicity. At present, a direct interaction of cochlear ischemia and aminoglycoside ototoxicity is still lacking. This study demonstrated a direct evidence of increased gentamicin (GM) ototoxic sensitivity in chronic guinea pig models of transient cochlear ischemia. No permanent auditory changes were observed after a single dose of GM (125 mg/kg) or after transient cochlear ischemia for 30 min. Persistent and significant auditory threshold shift was detected when GM was given after transient cochlear ischemia. Cochlear hair cells and spiral ganglion neurons are the major regions affected. Apoptosis contributes to hair cell death during acute interaction of ischemia and GM ototoxicity. Increased apoptotic cell death was also depicted when GM crossreacted with hypoxia in vitro, using cochlear cell lines. Generation of reactive oxygen species, loss of mitochondrial membrane potential, calcium release, and caspase-dependent apoptotic cell death were shown during the interaction of hypoxia and GM ototoxicity in vitro. This synergistic ototoxicity may be critical to aminoglycoside-induced hearing loss in clinical scenarios. The results should improve our understanding of the interacting mechanism and potential preventive strategy to aminoglycoside ototoxicity.

Hyperbaric oxygen and steroid therapy for idiopathic sudden sensorineural hearing loss

In our controlled retrospective analysis of medical records in tertiary care academic medical center, we aimed to investigate the therapeutic effects of hyperbaric oxygen (HBO) therapy combined with steroid administration for idiopathic sudden sensorineural hearing loss (ISSNHL) in comparison with that of steroid administration alone. Our subjects were 130 consecutive inpatients with ISSNHL (hearing levels >/=40 dB; time from the onset of hearing loss to the start of treatment </=30 days). Sixty-seven patients underwent HBO plus steroid therapy (HBO group), and 63 were given steroids alone (steroid group). Hearing recovery was evaluated by grade assessment and by the improvement in hearing compared to that in the unaffected contralateral ear. The cure rate and hearing improvement rate were not statistically different between the two groups; however, the recovery rate was significantly higher in the HBO group than in the steroid group (59.7% vs. 39.7%; P < 0.05). With regard to patients with initial hearing levels of >/=80 dB, the hearing improvement rate was significantly higher in the HBO group than in the steroid group (51.1 +/- 7.0% vs. 27.1 +/- 7.8%; P < 0.05), while in patients whose initial hearing levels were <80 dB, hearing outcomes were not statistically different between the two groups. In both the HBO and steroid groups, patients with initial hearing levels of <80 dB showed a better hearing improvement rate than those with initial hearing levels of >/=80 dB. In conclusion HBO therapy shows a significant additional effect in combination with steroid therapy for ISSNHL, particularly in patients with severe hearing loss.

Clinical Features in the Management of Selected Hypertensive Emergencies

A hypertensive emergency is a clinical diagnosis that is appropriate when marked hypertension is associated with acute target-organ damage; in this setting, lowering of blood pressure (BP) is typically begun within hours of diagnosis. For hypertensive urgency with no acute target-organ damage, BP lowering may occur over hours to days. A hypertensive emergency may present with cardiac, renal, neurologic, hemorrhagic, or obstetric manifestations, but prompt recognition of the condition and institution of rapidly acting parenteral therapy to lower BP (typically in an intensive care unit) are widely recommended. For aortic dissection, the systolic BP target is lower than 120 mm Hg, to be achieved during the first 20 minutes using a beta-blocker (typically esmolol) and a vasodilator to reduce both shear stress on the aortic tear and the BP, respectively. Otherwise, sodium nitroprusside is the agent with the lowest acquisition cost and longest record of successful use in hypertensive emergencies; however, it is metabolized to toxic thiocyanate and cyanide. Other attractive agents include fenoldopam mesylate, nicardipine, and labetalol; in pregnant women, magnesium and nifedipine are used commonly. Most authors suggest a reduction in mean arterial pressure of approximately 10% during the first hour and a further 10% to 15% during the next 2 to 4 hours; hypoperfusion can result if the BP is lowered too suddenly or too far (eg, into the range of <140/90 mm Hg). Oral antihypertensive therapy can usually be instituted after 6 to 12 hours of parenteral therapy, and the patient moved out of the intensive care unit, when consideration should be given to screening for secondary causes of hypertension. Long-term follow-up to ensure adequate control of hypertension is necessary to prevent further target-organ damage and recurrence of another hypertensive emergency.