Transtympanic dexamethasone application in Ménière's disease: an alternative treatment for intractable vertigo

Autoinflammatory characteristics and short-term effects of delivering high-dose steroids to the surface of the intact endolymphatic sac and incus in refractory Ménière's disease

Objective

To investigate immune-related genetic background in intractable Meniere’s disease (MD) and the immediate results of a novel therapy by delivering steroids to the surface of the intact endolymphatic sac (ES) and incus in a sustainable manner.

Case report and methods

Candidate genes involved in immune regulation were sequenced using a next-generation sequencing method in a patient with intractable MD. Mutations were confirmed using the Sanger sequencing method. The ES was exposed, and gelatin sponge particles were immersed in high-dose methylprednisolone solution and placed onto the surface of ES. “L”-shaped gelatin sponge strips were immersed in dexamethasone solution and served as a guiding device for the steroids by touching the incus and gelatin sponge particles on the surface of the ES. Gelatin sponge particles immersed in dexamethasone solution were placed around the gelatin sponge strips and sealed using fibrin glue.

Results

Autoinflammation in the refractory MD case was indicated by genotype, including novel heterozygous mutations of PRF1, UNC13D, SLC29A3, ITCH, and JAK3, as well as phenotype. The vertigo was fully relieved immediately after operation. Tinnitus and aural fullness were resolved 3 weeks after operation, whereas hearing improved in 2 mon postoperation. No recurrence was noted during the 5-monfollow-up, and the final MRI supported the novel therapeutic hypothesis.

Conclusion

Autoinflammation was involved in a refractory MD. This novel therapy, which involves the delivery of steroids to the surface of the intact ES and incus, is effective in relieving vertigo and tinnitus and improves hearing function of refractory MD.

Intratympanic corticosteroids in Ménière's disease: A mini-review

This article reviews the effectiveness of intratympanic corticosteroids for vertigo control in Ménière's disease at 2-years follow-up according to the guidelines expressed by the American Academy of Otolaryngology-Head & Neck Surgery. Despite the increased use of intratympanic corticosteroids for vertigo control in Ménière's disease there is debate as to their effectiveness, particularly compared to gentamicin. Even so, after just a single course of injections, corticosteroids can reliably provide complete vertigo control (Class A) at 2-years in about 50% of cases as indicated in a recent double-blind randomized controlled clinical trial (Patel et al., 2016). But the effectiveness of intratympanic corticosteroids truly increases when treatment is provided 'as-needed', whereby complete vertigo control is established in up to 91% of cases. On the basis of available literature, there is good evidence to recommend the use of intratympanic steroid treatment for vertigo control in Ménière's disease, but patients must be monitored for non-response. The rationale for treating patients as-needed and the possible reasons for corticosteroid non-response are discussed.

Sudden hearing loss: an effectivity comparison of intratympanic and systemic steroid treatments

Corticosteroid treatment has been considered the most effective treatment modality for sudden sensorineural hearing loss so far. Application route of corticosteroids may vary. We have designed a prospective randomized case-controlled clinical trial to evaluate the effectivenesses of the different application routes of steroids in the treatment of SSHL. Thirty-five patients were distributed randomly to two groups which were treated with either 'oral' or 'intratympanic' corticosteroids. Intratympanic steroid administration was performed three times every other day transtympanically. At the end of third month, recovery rate in the 'intratympanic' group was 84.2%, whereas in the 'oral' group, it was 87.5%. The difference between the recovery rates was not statistically significant. There were no major complications related to transtympanic steroid administration. These findings support that intratympanic steroid therapy is an alternative to systemic steroid therapy in the initial treatment of sudden hearing loss. In addition, transtympanic technique is an easy to perform and safe method for delivering steroids into the inner ear.

Rate of tympanic membrane perforation after intratympanic steroid injection

PURPOSE

To determine the rate of persistent tympanic membrane perforation after intratympanic steroid injection. To determine which comorbid conditions and risk factors are associated with prolonged time to perforation closure following intratympanic steroid injection.

MATERIALS AND METHODS

Clinical data were gathered for patients who had undergone intratympanic steroid injection to treat sudden sensorineural hearing loss or Ménière's disease. Primary outcomes analysis included rate of persistent tympanic membrane perforation, defined as perforation at least 90days following last injection, and time to perforation healing. Age, sex, number of injections, smoking status, diabetes mellitus, previous head and neck irradiation, and concurrent oral steroids, were analyzed as potential predictors of persistent perforation.

RESULTS

One hundred ninety two patients were included in this study. Three patients (1.6%) had persistent tympanic membrane perforations. All three patients received multiple injections. One patient underwent tympanoplasty for repair of persistent perforation. The median time to perforation healing was 18days. There was no statistically significant variable associated with time to perforation healing. However, patients with prior history of head and neck radiation averaged 36.5days for perforation healing compared to 17.5days with no prior history of radiation and this approached statistical significance (p=0.078).

CONCLUSIONS

The rate of persistent tympanic membrane perforation following intratympanic steroid injection is low. Patients with a history of radiation to the head and neck may be at increased risk for prolonged time for closure of perforation.

Stress axis plasticity during vestibular compensation in the adult cat

The postural, ocular motor, perceptive and neurovegetative syndromes resulting from unilateral vestibular neurectomy (UVN) symptoms could generate a stress and thereby activate the hypothalamo-pituitary-adrenal (HPA) axis. This study was aimed at determining whether UVN causes changes in the activity of the HPA axis, and if so, evaluating the time course of changes associated with UVN syndrome. At the cellular level, corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) immunoreactivity (Ir) were analyzed and quantified in the paraventricular nucleus (PVN) and the vestibular nuclei (VN) complex of cats killed early (1 and 7 days) or late (30 and 90 days) after UVN. Dopamine-beta-hydroxylase (DbetaH), the enzyme synthesizing noradrenaline was examined in the locus coeruleus (LC) in these same cats. At the behavioral level, the time course of recovery of the postural and locomotor functions was quantified at the same postoperative delays in another group of UVN cats. Results showed a significant bilateral increase in the number of both AVP-Ir and CRF-Ir neurons in the PVN and an increase of DbetaH-Ir neurons in the LC at 1, 7 and 30 days after UVN. This increased number of neurons was no longer observed at 90 days. Conversely, a significant bilateral decrease of CRF-Ir neurons was observed in the VN at these same postlesion times, with a similar return to control values at 90 days. Our behavioral observations showed strong posturo-locomotor functional deficits early after UVN (1 and 7 days), which had recovered partially at 30 days and completely by 90 days postlesion. We demonstrate a long-lasting activation of the HPA axis, which likely reflects a chronic stress, experienced by the animals, which corresponds to the time course of full vestibular compensation, and which is no longer present when the animals are completely free of posturo-locomotor symptoms at 90 days.

Localized cell and drug delivery for auditory prostheses

Localized cell and drug delivery to the cochlea and central auditory pathway can improve the safety and performance of implanted auditory prostheses (APs). While generally successful, these devices have a number of limitations and adverse effects including limited tonal and dynamic ranges, channel interactions, unwanted stimulation of non-auditory nerves, immune rejection, and infections including meningitis. Many of these limitations are associated with the tissue reactions to implanted auditory prosthetic devices and the gradual degeneration of the auditory system following deafness. Strategies to reduce the insertion trauma, degeneration of target neurons, fibrous and bony tissue encapsulation, and immune activation can improve the viability of tissue required for AP function as well as improve the resolution of stimulation for reduced channel interaction and improved place-pitch and level discrimination. Many pharmaceutical compounds have been identified that promote the viability of auditory tissue and prevent inflammation and infection. Cell delivery and gene therapy have provided promising results for treating hearing loss and reversing degeneration. Currently, many clinical and experimental methods can produce extremely localized and sustained drug delivery to address AP limitations. These methods provide better control over drug concentrations while eliminating the adverse effects of systemic delivery. Many of these drug delivery techniques can be integrated into modern auditory prosthetic devices to optimize the tissue response to the implanted device and reduce the risk of infection or rejection. Together, these methods and pharmaceutical agents can be used to optimize the tissue-device interface for improved AP safety and effectiveness.

Longitudinal results with intratympanic dexamethasone in the treatment of Ménière's disease

OBJECTIVE

To assess patient satisfaction with vertigo control using intratympanic (IT) dexamethasone (12 mg/mL) for medically refractory unilateral Ménière's disease.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral neurotology clinic.

PATIENTS

One hundred twenty-nine subjects diagnosed with unilateral Ménière's disease still having vertigo despite medical therapy.

INTERVENTION

IT dexamethasone injections as needed to control vertigo attacks.

MAIN OUTCOME MEASURE

A Kaplan-Meier time-to-event method was used to determine the rate of "survival," meaning sufficient satisfaction with vertigo control that the subject did not wish to have subsequent ablative treatment. "Failure" was defined as poor control and the choice to proceed to ablative treatment.

RESULTS

Acceptable vertigo control ("survival") was achieved in 117 (91%) of 129 subjects. Vertigo control required only one dexamethasone injection in 48 (37%), 2 injections in 26 (20%), 3 injections in 18 (14%), and 4 injections in 10 (8%). More than 4 injections were needed in 15 subjects (21%). Of 12 failures (9%), 9 occurred within 6 months of the first IT dexamethasone injection. Follow-up data for 2 years were available for 96 subjects. Of these, 87 (91%) had vertigo control with IT dexamethasone, of whom 61 (70)% required no further injections after 2 years, 23 (26%) continued to receive IT dexamethasone injections, and 3 (3%) chose IT gentamicin treatment.

CONCLUSION

IT dexamethasone injection therapy on an as-needed outpatient basis can provide vertigo control that is satisfactory in patients with Ménière's disease. The Kaplan-Meier method addresses the need for an outcome measure suited to repeated treatments and variable lengths of follow-up. However, due to the retrospective nature of this study, the presence of bias caused by loss of subjects from follow-up cannot be ruled out.

Intratympanic steroid therapy for inner ear diseases, a review of the literature

To evaluate the value of clinical trials on intratympanic steroid therapy in Ménière's disease (MD), idiopathic sudden sensorineural hearing loss (ISSNHL) and rapidly progressive sensorineural hearing loss (RPSNHL). Medline and Pubmed databases from 1966 to present were searched for clinical studies on intra- or transtympanic (cortico)steroid therapy of MD, ISSNHL and RPSNHL. Results were cross-checked with additional databases to obtain a complete data set. Clinical trials were evaluated on the basis of comparability, internal and external validity. Articles were judged using the following questions: was a randomised double-blind controlled trial performed? Which criteria were used to confirm the diagnosis of MD, ISSNHL, RPSNHL? Which therapy was evaluated? How long was the follow-up? Which criteria were used to evaluate the results? Reliable evidence on the efficiency, optimum dosage and administration schedule of intratympanic steroid therapy in MD, ISSNHL and RPSNHL is lacking, therefore further investigation is required.

Dexamethasone Pharmacokinetics in Guinea Pig Inner Ear Perilymph

AIM

To study the dexamethasone pharmacokinetics in the inner ear perilymph of guinea pigs using high-pressure liquid chromatography.

METHODS

Sixty-five guinea pigs were divided into three groups. In the first group, the drug application protocol used an intra-abdominal dose of 0.5% dexamethasone 4 mg x kg(-1). In the second group, an intratympanic application dose of 0.5% dexamethasone 150 microl was used. The third group was the control group. The concentrations of dexamethasone in inner ear perilymph were determined by high-pressure liquid chromatography.

RESULTS

The perilymph concentration-time curves of dexamethasone conformed to a one-compartment open model after an intra-abdominal application. The Cmax was 0.927 +/- 0.008 mg x l(-1), the Tmax 1.47 +/- 0.04 h, the T(1/2K) 2.92 +/- 0.056 h, the AUC 5.533 +/- 0.05 mg x h x l(-1), the T(1/2Ka) 0.47 +/- 0.024 h. After an intratympanic application, the perilymph concentration-time curves of dexamethasone also conformed to a one-compartment open model. The Cmax was 0.201 +/- 0.006 mg x l(-1), the Tmax 0.117 +/- 0.06 h, the AUC 0.868 +/- 0.004 mg x h x l(-1), the T(1/2K) 2.918 +/- 0.089 h, the T(1/2Ka) 0.161 +/- 0.009 h. Compared to the intra-abdominal application, the intratympanic application resulted in similar levels of inner ear perilymph drug concentrations in 30 min.

CONCLUSION

Dexamethasone can penetrate the blood-labyrinthine barrier after intra-abdominal application. Dexamethasone can enter into perilymph after intratympanic application. Under the condition of the study, the intratympanic application resulted in a similar level of inner ear perilymph drug concentrations compared to the intra-abdominal application in 30 min.

Local inner-ear drug delivery and pharmacokinetics

Several drugs that are applied directly to the inner ear are in widespread clinical use for the treatment of inner-ear disorders. Many new substances and drug delivery systems specific to the inner ear are under development and in some cases are being evaluated in animal experiments and in clinical studies. However, the pharmacokinetics of drugs in the inner ear is not well defined and the field is plagued by technical problems in obtaining pure samples of the inner-ear fluids for analysis. Nevertheless, a basic understanding of the mechanisms of drug dispersal in the inner ear has emerged, which facilitates the design and interpretation of future pharmacokinetic studies.

Dexamethasone inner ear perfusion by intratympanic injection in unilateral Ménière's disease: a two-year prospective, placebo-controlled, double-blind, randomized trial

OBJECTIVE

To investigate the efficacy of dexamethasone inner ear perfusion by intratympanic injection in hearing loss, tinnitus, aural fullness, and vertigo in the treatment of unilateral Ménière's disease and compare it with the control group.

STUDY DESIGN AND SETTING

A prospective, randomized, double-blind study with 2-year follow-up comparing changes secondary to dexamethasone inner ear perfusion versus placebo consisting of saline solution.

PATIENTS

Twenty-two patients having definite Ménière's disease as outlined by the 1995 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium. All the patients were older than 18 years of age and were not receiving any other form of treatment with steroids for their Ménière's disease.

METHOD

Five consecutive daily intratympanic injections of dexamethasone or placebo to the involved ear.

RESULTS

In the dexamethasone group at 2-year follow-up, complete control of vertigo (class A) was achieved in 9 of 11 patients (82%) and substantial control of vertigo (class B) in the remaining 2 patients (18%.) In the control group only 7 of 11 patients (64%) finished the 2-year follow-up because in the other 4 patients (36%) we had to give another treatment for the continuing vertigo and thus they were classified as failure (class F.) From the 7 patients who have finished the follow-up of 2 years in the control group, 4 patients (57%) achieved class A, 2 patients (29%) achieved class C, and 1 patient (14%) class F.

CONCLUSIONS

Dexamethasone (4 mg/mL) inner ear perfusion in a group of patients with unilateral Ménière's disease (Shea's stage III) showed 82% of complete control of vertigo over placebo (57%). There was also a subjective improvement in tinnitus (48%), hearing loss (35%), and aural fullness (48%) in the dexamethasone group compared with 20%, 10%, and 20% respectively in the control group.

Interaction between the hypothalamic-pituitary-adrenal axis and behavioural compensation following unilateral vestibular deafferentation

Vestibular compensation is defined as the process of behavioural recovery that occurs following the loss of sensory input from one or both vestibular labyrinths. The visual and postural instability resulting from the vestibular damage must alter the homeostasis of the subject; however, very little research has been conducted that investigates the interaction between vestibular compensation and the adaptive stress response of the body, i.e. the hypothalamic-pituitary-adrenal (HPA) axis. The aim of this review is to describe and evaluate the experimental evidence indicating a link between vestibular compensation and the body's response to stress, via the HPA axis.

Pharmacology of the vestibular system

In the past year significant advances have been made in our understanding of the neurochemistry and neuropharmacology of the peripheral and central vestibular systems. The recognition of the central importance of excitatory amino acids and their receptors at the level of the hair cells, vestibular nerve and vestibular nucleus has progressed further, and the role of nitric oxide in relation to activation of the N-methyl-D-aspartate receptor subtype is becoming increasingly clear. Increasing evidence suggests that excessive N-methyl-D-aspartate receptor activation and nitric oxide production after exposure to aminoglycoside antibiotics is a critical part of hair cell death, and new pharmacological strategies for preventing aminoglycoside ototoxicity are emerging as a result. Conversely, the use of aminoglycosides to lesion the peripheral vestibular system in the treatment of Meniere's disease has been studied intensively. In the vestibular nucleus, new studies suggest the importance of opioid, nociceptin and glucocorticoid receptors in the control of vestibular reflex function. Finally, the mechanisms of action and optimal use of antihistamines in the treatment of vestibular disorders has also received a great deal of attention.