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Abstract of the Week

August Topic of the month: Motion Sensitivity

No 482: August 8, 2019

Wang L, Cao Y, Tan C, Zhao Q, He S, Niu D, Tang G, Zou P, Xing L. Uncoupling VOR and vestibuloautonomic retention to Coriolis acceleration training in student pilots and control subjects. J Vestib Res. 2017.
 
Abstract
 
PURPOSE: Explore the different vestibular physiologic response retention patterns after Coriolis acceleration training in student pilots and extend the results for use with Chinese astronauts in the future.

METHODS: Twelve healthy control male subjects were screened from males familiar with vestibular training and who physically resembled the astronauts. Fourteen student pilots were selected from 23 participants by rotational vestibular function tests. All subjects were exposed to five-day continuous or intermittent Coriolis acceleration training. Subjective motion sickness (MS) symptom scores, electrocardiography, electrogastrography (EGG), post-rotatory nystagmus and renin-angiotensin system responses were measured before, during and after rotational vestibular function tests at different times after vestibular training.
RESULTS: Subjects could tolerate 10 min or 15 min of vestibular with mild MS symptoms. Retention of vestibular autonomic responses (retention of MS symptom scores, heart rate variability, power density of EGG, variations in levels of arginine vasopressin) were approximately 1 week for control subjects and approximately 5 weeks for student pilots. Decreases in slow-phase velocity of post-rotatory nystagmus were maintained for 14 weeks for control subjects and 9 weeks for student pilots.

CONCLUSIONS: Retention of the vestibulo-autonomic reaction after vestibular training was different for control subjects and student pilots. All parameters related to autonomic responses could be maintained at low levels after vestibular training for approximately 1 week for control subjects and approximately 5 weeks for student pilots. Uncoupling patterns between post-rotatory nystagmus and the vestibulo-autonomic reaction may be helpful in the design of clinical rehabilitation plans for balance-disorder patients and for exploration of artificial gravity in future space missions.

 
PMID: 29064824

July Topic of the month: Vestibulotoxicity

No 481: July 31, 2019

Prayuenyong P, Taylor JA, Pearson SE, Gomez R, Patel PM, Hall DA,  Kasbekar AV, Baguley DM. Vestibulotoxicity Associated With Platinum-Based Chemotherapy in Survivors of Cancer: A Scoping Review. Front Oncol. 2018 Sep 25;8:363. doi: 10.3389/fonc.2018.00363. eCollection 2018. 

Abstract
 
Background: Cochleotoxicity following the treatment with platinum-based chemotherapy is well documented. The potential for vestibulotoxicity is still unclear. This scoping review examined the extent of current research literature, summarized research findings and identified research gaps regarding vestibular-related adverse effects associated with platinum-based chemotherapy in survivors of cancer. Methods: Inclusion criteria followed the PICO principles: Participants, adult, and pediatric cancer patients of any cancer type; Intervention, platinum-based chemotherapy (such as cisplatin, carboplatin, and oxaliplatin); Control, none or any; Outcomes, vestibular-related adverse effects. English language articles published since 1978 were retrieved. Seventy-five eligible studies were identified from a systematic literature search, and relevant data were charted, collated, and summarized. Results: Testing for vestibulotoxicity predominately featured functional evaluation of the horizontal semicircular canal using the caloric and rotational tests. The rate of abnormal vestibular function test results after chemotherapy administration varied from 0 to 50%. The results of objective testing did not always correspond to patient symptoms. There is tentative support for patients with pre-existing loss of vestibular function to be more likely to experience vestibular toxicity after dosing with cisplatin. Conclusions: A number of studies reported significant evidence of vestibular toxicities associated with platinum-based chemotherapy, especially cisplatin. This scoping review emphasizes that vestibular toxicity needs more attention and comprehensive evaluation. Specifically, studies that analyse cumulative dose of platinum-based chemotherapy, affected sites of lesion in vestibular end organs, and the correlation and temporal patterns of cochlear and vestibular toxicity are needed. 
 
PMID: 30319960

 

No 480: July 26, 2019

Handelsman JA. Vestibulotoxicity: strategies for clinical diagnosis and rehabilitation. Int J Audiol. 2018 Sep;57(sup4):S99-S107. doi: 10.1080/14992027.2018.1468092. Epub 2018 May 9.
 
Abstract
 
OBJECTIVE:  The purpose of this article is to discuss the most commonly prescribed vestibulotoxic medications and their impact on the vestibular system, to describe the clinical features of vestibular ototoxicity including symptoms reported by patients, and to describe assessment tools that may be used in a monitoring programme, including the functional impact of vestibular loss. Recently published data from a cohort of patients exposed to systemic aminoglycosides (AGS) are summarised, which highlight the importance of monitoring. The role and importance of vestibular rehabilitation in treating affected individuals is discussed.

DESIGN:  This is a descriptive article.
 
STUDY SAMPLE:  Recently published data from 71 patients with cystic fibrosis with AGS exposure are summarised.

RESULTS:  Recently published data from a cohort of patients exposed to systemic AGS reveal a high prevalence of vestibular system involvement.

CONCLUSIONS:  Evidence suggests that including assessment of vestibular function in a programme to monitor for ototoxic damage is essential. While suggestions about possible components of a monitoring programme are made, the need for further study in order to determine an ideal protocol for assessing vestibular system function during and following exposure to toxic agents is stressed.

 
PMID: 29741128
 

No 479: July 17, 2019

Van Hecke R, Van Rompaey V, Wuyts FL, Leyssens L, Maes L.  Systemic Aminoglycosides-Induced Vestibulotoxicity in Humans.  Ear Hear. 2017 Nov/Dec;38(6):653-662. doi: 10.1097/AUD.0000000000000458.

Abstract
 
OBJECTIVES:  This systematic review aimed to investigate the prevalence and characteristics of vestibular adverse effects of aminoglycoside (AG) therapy in humans and to analyze objective vestibular tests for the detection of AG-induced vestibulotoxicity.

DESIGN:  PubMed, Cochrane Database, Web of Science, and reference lists of all included studies were screened by two independent researchers. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Studies were included according to preset inclusion criteria and reported outcomes of studies evaluating vestibular function using one or more objective vestibular function tests in adults and children after systemic AG administration. The methodological quality of each study was assessed using the quality assessment tool for quantitative studies. Interrater reliability was established using Cohen's Kappa.

RESULTS:  Twenty-seven studies were included, with the vast majority showing AG-induced vestibulotoxic side effects, ranging from 0 to 60%. Most studies reported AG-induced abnormalities by caloric and rotatory testing, whereas only a few studies reported using video Head Impulse test and vestibular evoked myogenic potential testing.

CONCLUSIONS:  Because type I hair cells (particularly of the semicircular canals) are more susceptible to ototoxicity, video Head Impulse test and vestibular evoked myogenic potential testing seem more promising for the early detection of vestibulotoxicity than caloric and rotatory testing. Prospective studies using an extensive vestibular test battery are needed to further characterize the impact of AGs on the different vestibular end organs and to identify the most sensitive vestibular technique for the early detection of vestibulotoxicity.

PMID: 28650850

 

No 478: July 10, 2019

 Rutka J. Aminoglycoside Vestibulotoxicity. Adv Otorhinolaryngol. 2019;82:101-110. doi: 10.1159/000490277. Epub 2019 Jan 15. 

 
Abstract
 
Many pharmaceuticals have ototoxicity (both cochlear and/or vestibular) as part of their adverse medication profile. The aminoglycoside class of antimicrobials has been especially well studied in this regard. Many questions remain unanswered as to how to best monitor and prevent this complication. A bilateral vestibular loss profoundly affects an individual's quality of life, physical activities, and overall independence. Paradoxically, the effects of gentamicin ototoxicity have provided further insight into the workings of the vestibular system, especially the vestibulo-ocular reflex. The microbiological activity, therapeutic use, toxicities, and genetics predisposing a person to aminoglycoside ototoxicity are presented. The clinical importance of recognizing ataxia, disequilibrium, and oscillopsia as presenting symptoms for vestibulotoxicity rather than hearing loss or vertigo is stressed. Documented risk factors and new observations regarding the spectrum of vestibular dysfunction and differences in vestibulotoxicity from multiple daily dosing vs. single daily dosing schedules are presented for the first time. While most vestibulotoxicity arises from systemic aminoglycoside administration, intratympanic application has been used therapeutically for intractable Ménière's disease. Commercially available ototopical aminoglycoside preparations for the treatment of external/middle ear disease in the presence of a tympanic membrane defect have also been documented to cause unintentional ototoxicity. 
PMID: 30947191

 

June Topic of the month: Visual Dependence

No 477: June 26, 2019

Roberts RE, Da Silva Melo M, Siddiqui AA, Arshad Q, Patel M. Vestibular and oculomotor influences on visual dependency.  J Neurophysiol. 2016 Sep 1;116(3):1480-7. doi: 10.1152/jn.00895.2015. Epub 2016 Jun 29.

Abstract

The degree to which a person relies on visual stimuli for spatial orientation is termed visual dependency (VD). VD is considered a perceptual trait or cognitive style influenced by psychological factors and mediated by central reweighting of the sensory inputs involved in spatial orientation. VD is often measured with the rod-and-disk test, in which participants align a central rod to the subjective visual vertical (SVV) in the presence of a background that is either stationary or rotating around the line of sight-dynamic SVV. Although this task has been employed to assess VD in health and vestibular disease, what effect torsional nystagmic eye movements may have on individual performance is unknown. Using caloric ear irrigation, 3D video-oculography, and the rod-and-disk test, we show that caloric torsional nystagmus modulates measures of VD and demonstrate that increases in tilt after irrigation are positively correlated with changes in ocular torsional eye movements. When the direction of the slow phase of the torsional eye movement induced by the caloric is congruent with that induced by the rotating visual stimulus, there is a significant increase in tilt. When these two torsional components are in opposition, there is a decrease. These findings show that measures of VD can be influenced by oculomotor responses induced by caloric stimulation. The findings are of significance for clinical studies, as they indicate that VD, which often increases in vestibular disorders, is modulated not only by changes in cognitive style but also by eye movements, in particular nystagmus.

PMID: 27358321

Link to free article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5040385/

No 476: June 19, 2019

Maire R, Mallinson A, Ceyte H, Caudron S, Van Nechel C, Bisdorff A, Magnusson M, Petersen H, Kingma H, Perrin P.  Discussion about Visual Dependence in Balance Control: European Society for Clinical Evaluation of Balance Disorders. J Int Adv Otol. 2017 Dec;13(3):404-406. doi: 10.5152/iao.2017.4344.

Abstract

The executive committee of the European Society for the clinical evaluation of balance disorders meets annually to address equilibrium problems that are not well understood. This is a review paper on discussions in the latest meeting we held.

MATERIALS AND METHODS: Seeing patients with vestibular disorders who end up depending on visual information as part of their compensation process is a common clinical occurrence. However, this "visual dependence" can generate symptoms, which include nausea, sensations of imbalance, and anxiety. It is unclear how this develops, as symptoms can be widely variable from patient to patient. There are several triggering factors to this symptom set, and quantifying it in a given patient is extremely difficult Results: The committee agreed that the presence of this symptom set can be suggestive of vestibular pathology, but the pathology does not have to be present. As a result, there is no correlation between symptom severity and test results.

CONCLUSION: Visual dependence can often be present in a patient, although little, if any, measurable pathology is present. It is important to emphasize that although we cannot accurately measure this with either standardized testing or pertinent questionnaires, "hypersensitive" patients have a genuine disease and their symptoms are not of psychiatric origin.

PMID: 29360093

No 475: June 12, 2019

Bronstein AM, Dieterich M. Long-term clinical outcome in vestibular neuritis. Curr Opin Neurol. 2019 Feb;32(1):174-180. doi: 10.1097/WCO.0000000000000652.

Abstract

PURPOSE OF REVIEW: To review recent work on clinical and imaging aspects of vestibular neuritis (or acute vestibular syndrome), in particular with a view to identifying factors predicting long-term clinical outcome.

RECENT FINDINGS: Evidence for a role of inflammation in the vestibular nerve, and the presence of Gadolinium enhancement acutely in vestibular neuritis, is accruing. Visual dependence, anxiety and somatization traits predict the development of chronic dizziness after acute vestibular neuritis. Adaptation to asymmetric rotation is impaired in vestibular neuritis and this may indicate insufficient central compensation in chronic dizzy patients. Corticosteroids appear ineffective at improving long-term clinical outcome. Functional imaging changes during the central compensation period lead to structural brain changes; both processes correlate with clinical recovery.

SUMMARY: Vestibular neuritis appears to be the result of postviral neuroinflammation of the vestibular nerve. However, long-term prognosis is not dependent on the magnitude of the peripheral residual damage (as measured with caloric and video head-impulse test). Instead, a combination of visuovestibular psychophysical factors (visual dependence), psychological traits and dysfunctional vestibular perception are relevant. Several functional and structural neuroimaging changes develop after vestibular neuritis, which reflect and underlie the aforementioned psychophysiological and psychological features.

PMID: 30566414

No 474: June 7, 2019

Smyth N, Flynn M, Rajcani J, F Hucklebridge M, Thorn L, Wood C, Golding J, Evans P, Clow A.  Attenuated cortisol reactivity to psychosocial stress is associated with greater visual dependency in postural control.  Psychoneuroendocrinology. 2019 Jun;104:185-190. doi: 10.1016/j.psyneuen.2019.02.028. Epub 2019 Mar 2.

Abstract

Despite known anatomical links between the hypothalamic-pituitary-adrenal (HPA) axis and the vestibular system, there are no studies on the relationship between postural control and HPA axis function. Visual dependence in postural control, often measured by increased postural sway on exposure to visual motion, is an indication of altered visual-vestibular integration with greater weighting towards visual cues for balance. Visual dependence is more common in older age and a range of vestibular and non-vestibular health conditions. The relationship between visual dependence in postural control was investigated in relation to cortisol reactivity to psychosocial stress (using the Trier Social Stress Test for groups: TSST-G), as an index of HPA axis function, in healthy young females. In those who exhibited a cortisol response (>2 nmol/l), a negative relationship between stress-induced cortisol reactivity and visual dependence in postural control was observed, since those with the largest cortisol response showed less visual motion induced postural sway (measured by force platform). This finding in healthy females indicates that subtle non-clinical differences in vestibular function are associated with dysregulated HPA axis activity as indicated by lower cortisol reactivity to psychosocial stress. It adds to the growing body of evidence linking blunted cortisol reactivity to stress to poor homeostatic regulation and potential negative health and behavioural outcomes.

PMID: 30856424

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