The Effect of Collagen Viscoelastoplasiticty on Reissner’s Membrane Displacement: A Graphic Analysis

Background: The aim of this study is to analyze the effect of collagen viscoelastoplasticity on the bulge displacement of Reissner’s membrane that is observed in endolymphatic hydrops and Meniere’s disease.

Methods: Viscoelastoplastic load–deformation characteristics for Reissner’s membrane were based on a reported collagen polymer model of the cochleo-saccular membranes. The projected bulge displacements of Reissner’s model membrane at key distention points were quantified trigonometrically and plotted graphically.

Results: Initial deformation is characterized by a membrane laxity with substantial stretch at low tension with projected bulge displacement of Reissner’s membrane approaching 30%. Intermediate deformation is characterized by a linear membrane stiffness with projected bulge displacement of Reissner’s membrane in the range of 30-40%. Terminal deformation is characterized by reduced stiffness with a disproportionate increase in membrane stretch with projected bulge displacement of Reissner’s membrane reaching a critical value of 50%, indicating a hemi-circular profile with imminent risk of rupture.

Conclusion: This collagen model of membrane viscoelastoplasticity demonstrates that at low pressure significant degrees of bulge displacement up to 30% can occur that may be reversible. The narrower 30-40% range of membrane displacement is one of the increasing deformity but without risk of rupture. Greater displacements approaching 50% indicate that the membrane is reaching a critical hemi-circular configuration with impending rupture.

Vestibular and auditory manifestations of migraine

PURPOSE OF REVIEW

The purpose of this narrative review is to discuss current literature about vestibular migraine and other cochleovestibular symptoms related to migraine.

RECENT FINDINGS

Vestibular migraine affects 2.7% of the US population. Misdiagnosis is common. The pathophysiology is currently unknown but new research shows that calcitonin gene-related peptide, which is implicated in migraine headaches, is expressed in the audiovestibular periphery. A recent large-scale placebo-controlled trial looking at metoprolol for vestibular migraine was terminated early due to poor recruitment; however, at study completion, no differences were seen between treatment arms. Many other audiovestibular symptoms have been shown to be associated with migraine, including tinnitus, hearing loss, aural fullness, otalgia, and sinus symptoms. Migraine is also associated with risk for developing numerous otologic conditions, including Meniere's disease, vestibular loss, Benign Paroxysmal Positional Vertigo, and sudden sensorineural hearing loss. There is now some evidence that patients may experience fluctuating hearing loss and aural fullness without vertigo in association with migraine, which is called cochlear migraine.

SUMMARY

Migraine can cause a variety of audiologic and vestibular symptoms, and further research is required to understand how migraine affects the inner ear.

Influence of sex hormones on vestibular disorders

PURPOSE OF REVIEW

Vestibular disorders are gender distributed with a higher prevalence in women. Although research has increased in this field, the mechanisms underlying this unbalance is unclear. This review summarises recent advances in this research sphere, and briefly discusses sex hormone effects on various vestibular conditions and highlights some recent theories.

RECENT FINDINGS

Recent work has identified a direct link between aberrant gonadal hormone levels and vestibular dysfunction. Benign paroxysmal positional vertigo research suggests that the disorder may be linked to the rapid decrease in oestrogen, observed in menopausal women, which disrupts otoconial metabolism within the inner ear. A successful hormonal therapeutic intervention study has advanced our knowledge of hormonal influences in the inner ear in Ménière's disease. Also, several studies have focused on potential mechanisms involved in the interaction between Vestibular Migraine, Mal de Debarquement Syndrome, and gonadal hormones.

SUMMARY

In females, gonadal hormones and sex-specific synaptic plasticity may play a significant role in the underlying pathophysiology of peripheral and central vestibular disorders. Overall, this review concludes that clinical assessment of female vestibular patients requires a multifaceted approach which includes auditory and vestibular medicine physicians, gynaecologists and/or endocrinologists, in conjunction with hormonal profile evaluations.

[A preliminary study on characteristics of wideband acoustic immittance in patients with Meniere's disease]

Objective:To explore the wideband absorbance characteristics of patients with Meniere's disease（MD）. Methods:Wideband acoustic immittance was performed in 52 patients with unilateral Meniere's disease（UMD） and 30 control subjects with normal hearing. All UMD patients underwent pure tone audiometry, 226 Hz acoustic immittance, wideband acoustic immittance, and gadolinium contrast MRI. Sixteen frequency points were chosen to analyze the wideband absorbance at ambient and peak pressure, and the subjects were grouped as UMD group vs. control group and asymptomatic group. The student's t-test was used to compare the absorbance difference between them. Results:Both at peak and ambient pressure, there was a significant difference between the MD group and control group at 1587 Hz, 2000 Hz, 2519 Hz, 3174 Hz, and 4000 Hz; the MD group was lower than the control group（P<0.05）; there were no differences between the asymptomatic group and the symptomatic group, there also was a significant difference between the asymptomatic group and control group at 1587-4000 Hz（P<0.05）. Conclusion:The wideband absorbance in MD patients was significantly reduced within the frequency range of 1587-4000 Hz, and wideband acoustic immittance seems to be cost-effective in predicting MD.

Allergy, Immunotherapy, and Alternative Treatments for Dizziness

Allergic reactions may result in central symptoms of dizziness, including nonspecific chronic imbalance, Meniere's disease, and autoimmune inner ear disease. Excepting first-generation antihistamines, and short-term use of steroids, most pharmacotherapies used to treat allergic rhinitis have limited benefit in treating allergically induced or related dizziness. Allergy immunotherapy and/or an elimination diet for diagnosed food allergies have been found to be effective treatments. Individuals diagnosed with autoimmune inner ear disease remain challenging to treat and may require high-dose, long-term steroid treatment, biologics, or immunomodulators for symptom control.

1D Convolutional Neural Networks for Detecting Nystagmus

Vertigo is a type of dizziness characterised by the subjective feeling of movement despite being stationary. One in four individuals in the community experience symptoms of dizziness at any given time, and it can be challenging for clinicians to diagnose the underlying cause. When dizziness is the result of a malfunction in the inner-ear, the eyes flicker and this is called nystagmus. In this article we describe the first use of Deep Neural Network architectures applied to detecting nystagmus. The data used in these experiments was gathered during a clinical investigation of a novel medical device for recording head and eye movements. We describe methods for training networks using very limited amounts of training data, with an average of 11 mins of nystagmus across four subjects, and less than 24 hours of data in total, per subject. Our methods work by replicating and modifying existing samples to generate new data. In a cross-fold validation experiment, we achieve an average F1 score of 0.59 (SD = 0.24) across all four folds, showing that the methods employed are capable of identifying periods of nystagmus with a modest degree of accuracy. Notably, we were also able to identify periods of pathological nystagmus produced by a patient during an acute attack of Ménière's Disease, despite training the network on nystagmus that was induced by different means.

Does Cognitive Dysfunction Correlate With Dizziness Severity in Meniére's Disease Patients

OBJECTIVE

Characterize the relationship between cognitive dysfunction and the dizziness severity in Meniére's disease (MD) patients.

STUDY DESIGN

Retrospective review.

SETTING

University-based tertiary medical center.

PATIENTS

Three hundred patients were evaluated for MD from 2015 to 2019. Excluding comorbid or alternative vestibular disorders, 29 patients with definite MD and available pre- and postintervention data were included for analysis.

INTERVENTIONS

A progressive protocol of salt restriction, diuretics, steroid and/or gentamycin injection, and endolymphatic sac decompression for those refractory to medical therapy.

MAIN OUTCOME MEASURES

Quality of life measured with the Dizziness Handicap Inventory (DHI) and cognitive function measured with the Cognitive Failures Questionnaire (CFQ). Pre- and posttreatment DHI and DHI subscale scores and change in these scores were correlated with pre- and posttreatment CFQ scores and change in CFQ with therapy.

RESULTS

Analysis showed a number of limited associations between improvement in DHI and improvement in CFQ. Total DHI scores failed to correlate scores or variation in scores with change in CFQ (p = 0.091 and p = 0.085, respectively). Improvement in the CFQ false-triggering domain was significantly associated with improvement in the DHI physical subscale (r = 0.491, p = 0.007) and was nonsignificantly associated with improvement in total DHI and DHI emotional subscale scores (r = 0.422, p = 0.016 and r = 0.399, p = 0.032).

CONCLUSIONS

The DHI correlates with several pre- and posttreatment measures of cognitive dysfunction (CFQ) in MD patients. However, change in DHI and CFQ with therapy correlate poorly. Overall, the commonly used DHI may fail to adequately assess cognitive dysfunction in MD patients possibly due to factors not directly implicated by measures of vestibular dysfunction, such as central nervous system or cognitive dysfunction; however, the specific physical and emotional subscales may offer helpful insight into cognitive dysfunction change/improvement with treatment.

[Characteristics of endolymphatic hydrops in low frequency descent sudden hearing loss]

Objective: To investigate the correlation between the clinical features of low-frequency sudden deafness and endolymphatic hydrops on gadolinium contrast in the inner ear. Methods: From July 2019 to January 2020, adult patients with unilateral low-frequency sudden deafness who were hospitalized in the outpatient clinic or ward of the Department of Otorhinolaryngology, Eye and ENT Hospital of Fudan University were selected and examined by audiology and gadolinium magnetic resonance (MR) angiography of inner ear. The same treatment plan was given, and the curative effect was recorded and followed up for more than 3 months. SPSS 20.0 software was used to analyze the correlation between the accompanying symptoms, deafness, and endolymphatic hydrops. Results: A total of 48 patients were included in the study, including 18 males and 30 females. The age ranged from 21 to 52 (37.3±10.0) years. All of them were unilateral, including 28 cases of left ear and 20 cases of right ear. The course of the disease was less than 2 weeks in all cases. The endolymphatic hydrops group included 14 cases, including vestibular hydrocele (6 cases), cochlear hydrops (2 cases), and cochlear and vestibular hydrops (6 cases). The incidence of dizziness in the endolymphatic hydrops group was higher than that in the non-hydrops group (6/14 vs 0/34, P<0.001). There was no significant difference in hearing values between the two groups at 125, 250, 500, 4 000 and 8 000 Hz (all P>0.05). The hearing in the endolymphatic hydrops group was worse than that in the non-hydrops group at 1 000 and 2 000 Hz. Conclusion: Compared with those without endolymphatic hydrops, patients with hydrops tend to have a higher incidence of dizziness, worse hearing at 1 000 and 2 000 Hz, and a worse prognosis.

[Etiological analysis of 1027 patients with vertigo in Xinjiang Autonomous Region]

Objective:To analysis the etiological characteristics of patients with vertigo in Xinjiang Uygur Autonomous Region. Method:The data of 1027 patients with vertigo and dizziness were collected and the etiology was analyzed. Result:The patients aged 51-60 years accounted for 27.95% of the total, followed by those aged 61-70 years accounted for 20.16% and those aged 41-50 years accounted for 17.33% s. There were 363 males and 664 females with a ratio of 1∶1.8. Benign paroxysmal positional vertigo （BPPV） was the most common cause in 233 cases （22.69%）, followed by vestibular migraine （VM） in 184 cases （17.92%）, Meniere's disease （MD） in 139 cases （13.53%）, sudden deafness with vertigo in 132 cases （12.85%）, and unknown cause in 114 cases （11.10%）. Conclusion:Among vertigo patients, women are significantly more than men. BPPV, VM, MD, and SHL are the most common vertigo causes. There are still some patients haven't received definite diagnosis.

[The serivation and establishment of the new disease name "Otogenic Vertigo" of integration of Chinese and Western medicine]

"Otogenic vertigo()" is a new disease name of modern traditional Chinese medicine(TCM), which is equivalent to otogenic vertigo of modern medicine.TCM has observed vertigo symptoms very early, and otogenic vertigo is included in many diseases recorded in ancient Chinese medicine, such as "xuanmao ()" , "diaoxuan()" , "vertigo()" , "wind vertigo()" , "true vertigo()" , etc. "True vertigo" is closer to the current otogenic vertigo than others. "Otogenic vertigo" is a new disease name created by experts of TCM otorhinolaryngology in the context of integrated Chinese and Western medicine.It was born in the 4th and 5th edition of Otorhinolaryngology of Traditional Chinese Medicine which is national unified textbooks of TCM. "Otogenic vertigo" has become a standard term , and it has been almost uniform definition, as its corresponding modern medicine diseases. The definition of vertigo in modern TCM internal medicine is broad, and otogenic vertigois also included.

[Analysis of clinical features of vestibular migraine]

Objective:To analyze the clinical features of Vestibular migraine（VM） and provide evidence for its accurate diagnosis and medical identification of flight personnel. Method:A total of 490 samples of VM patients were collected. Among them, 88 samples were secondary to benign paroxysmal positional vertigo（BPPV）, and 11 samples were co-occurring with Meniere's disease（MD）. All patients received drugs, lifestyle management, vestibular rehabilitation and other comprehensive treatment, and analyzed the clinical features and effect within 6 months. Result:①The male-female ratio of VM patients was 1∶1.95, the average age was （50.2±14.3） years old, （48.7±15.0） years old for males and （51.0±13.9） years old for females. No statistically significant differences were found（P>0.05）. The average duration was（54.5±84.8） months, （35.0±59.0） months for males and（64.7±94.0） months for females. The difference was statistically significant（P<0.05）. ②The main clinical symptoms are dizziness, migraine or previous history of migraine, fear of sound/noisy environment sensitivity, photophobia/visual sensitivity, nausea/vomiting, vestibular posture symptoms, tinnitus, hearing loss, etc. , diarrhea during dizziness or headache was one special symptom of VM; ③The abnormal rate of vestibular autorotation test（VAT） in 118 VM patients was 72.3%, while the abnormal rate of caloric test in 170 VM patients was 32.9%; ④The effective remission rate within 6 months of VM patients with secondary BPPV and MD was 78.6% and 83.4%, while the VM patients without secondary benign paroxysmal positional vertigo（BPPV） and Meniere's disease（MD） was 93.3%. The difference was statistically significant（P<0.05）. Conclusion:The clinical manifestations of VM patients were various. Female VM patients had higher incidence, the course of disease than male VM patients, diarrhea can be regarded as one of the clinical features distinguished from MD. The abnormal rate of VAT was higher in the common clinical examiniations of VM patients. VM patients treatment should focus on personalized prescription and lifestyle management, vestibular rehabilitation, and corresponding treatment at the same time should be given to patients with secondary BPPV and MD to improve the efficacy. The medical identification of flight personnel VM patients should be strictly controlled, pilots should be grounded, while flight combat personnel and flight technical personnel need chartered medical identification.

[Efficacy of semicircular canal occlusion in the treatment of fifteen pateints with Meniere's disease]

Objective:To investigate the long-term efficacy of semicircular canal occlusion in the treatment of refractory Meniere's disease. Method:Fifteen patients with Meniere's disease who underwent semicircular canal occlusion were reviewed. The preoperative and postoperative frequency of vertigo ,quality of life, hearing and tinnitus level were compared. All patients were followed for more than 24 months. Result:Postoperatively, vertigo was controlled effectively in all 15 cases, and the control rate was 100%, of which 11 cases were completely controlled（Grade A） and 4 cases were basically controlled（Grade B）. The improvement rate of quality of life was 100%. The hearing worse in 4 cases（26.7%） and stabilized in 11 cases（73.3%）. The tinnitus was relieved in 7 cases（46.7%）, unchanged in 7 cases（46.7%） and aggravated in 1 case（6.7%）. Conclusion:Semicircular canal occlusion can effectively control the vertigo symptoms of refractory Meniere's disease and improve the quality of life. The long-term efficacy of semicircular canal occlusion is definite, but there is a risk of hearing loss.

[Etiology and clinical symptoms of bilateral vestibulopathy]

OBJECTIVE

To identify etiology, clinical symptoms of bilateral vestibulopathy (BV) depending on etiology.

RESULTS

Idiopathic BV was identifies in one third of patients. The most common identified reasons are Meniere's disease, meningitis and ototoxicity. BV develops more often without incidental hearing loss in case of idiopathic, autoimmune etiology, ototoxicity and bilateral vestibular neuronitis. BV after neuroinfection is characterized by prompt symptoms development, bilateral severe hearing loss, Gain reduction in vHIT lower 0.4 and loss of more than 8 lines in DVA test.

CONCLUSION

BV after bilateral Meniere's disease is characterized by Gain higher than 0.4 and typical clinical picture of the primary disease.

[Clinical features and imaging characteristics of Meniere's disease verified by intravenous gadolinium contrast-enhanced magnetic resonance imaging]

Objective: To analyze the clinical features and imaging characteristics of Meniere's disease (MD)verified by intravenous gadolinium contrast-enhanced magnetic resonance imaging(MRI). Methods: A total of 174 patients with Meniere's disease were involved in this study between March 2016 and October 2017. All of them underwent 3D-fluid attenuated inversion recovery (FLAIR) MRI and presented endolymphatic hydrops and clinical characteristics of suspected Meniere's disease. The clinical characteristics, the grades of endolymphatic hydrops (EH) using Nakashima grading standard were analyzed, and the correlation between grade and clinical features was evaluated. Results: There were totally 174 patients (88 males, 86 females), with the age of 7-83 years [mean age of (51.0±15.0)] years. Age of onset and disease course was 7-83 years [mean age of (44.6±16.6) years], 36.0 (12.0, 111.0) months (from 2 days to 70 years), respectively. EH was found in all the patients, and 169 cases (97.1%) manifested as modest or severe hydrops. Among the 174 patients, 139 cases (79.9%) presented unilateral EH, and 35 cases (20.1%) presented bilateral EH. The degree of EH in the latter was more serious than the former. For 174 patients, clinical characteristics were inconsistent, which was not in accord with the existing diagnostic criteria. Furthermore, there was a correlation between degree of hydrops and degree of hearing loss (P<0.05). Conclusions: EH in Meniere's disease can be measured objectively by intravenous gadolinium contrast-enhanced MRI. Clinical characteristics in MD verified by EH are not accordant with the existing criteria, which means the significance of EH in diagnosis of MD. Moreover, there's a correlation between degree and distribution of hydrops and degree of hearing loss.