The role of cognitive processes in vestibular disorders

The Navigation Ability Test (NAT 2.0): From Football Player Performance to Balance Rehabilitation in Chronic Unilateral Vestibular Loss

Aim of the Study: in humans, spatial orientation consists of the ability to move around the environment through memorized and pre-programmed movements, according to the afferent sensory information of the body and environmental analysis of the Central Nervous System (CNS). The purpose of this study is to analyze the abilities of professional athletes, such as footballers, to use mental navigation systems, cognitive maps, and memorized motor patterns in order to obtain better physical performance and to obtain useful information for training both non-sports subjects and vestibular patients for rehabilitation purposes. Materials and Methods: all the motor performances of sportsmen, healthy non-sporting subjects, or vestibular patients are based on the acquisition of visual–spatial and training information. In this study, we analyzed the visual–spatial performance of 60 trained sportsmen (professional footballers), 60 healthy non-sports subjects, and 48 patients affected by chronic unilateral vestibular loss by means of the Navigation Ability Test 2.0. A score based on the number of targets correctly reached in the various tests quantifies the degree of performance of the subjects. Results: NAT 2.0 scores progressively improve from vestibular subjects to healthy non-sporting subjects to footballers. NAT 2.0 scores improve in all three subject groups as the number of tasks performed in all patient groups increases, regardless of gender and age. Conclusions: the analysis of performance data through NAT 2.0 in athletes (footballers) opens new perspectives for rehabilitation purposes, regardless of age, sex, and training conditions, both in healthy non-sporting subjects to improve their sporting potential and in patients affected by chronic vestibular dysfunction, in order to optimize their motor skills and prevent falls.

Sport as a Factor in Improving Visual Spatial Cognitive Deficits in Patients with Hearing Loss and Chronic Vestibular Deficit

Hearing loss and chronic vestibular pathologies require brain adaptive mechanisms supported by a cross-modal cortical plasticity. They are often accompanied by cognitive deficits. Spatial memory is a cognitive process responsible for recording information about the spatial environment and spatial orientation. Visual-spatial working memory (VSWM) is a kind of short-term working memory that allows spatial information to be temporarily stored and manipulated. It can be conditioned by hearing loss and also well-compensated chronic vestibular deficit. Vestibular rehabilitation and hearing aid devices or training are able to improve the VSWM. We studied 119 subjects suffering from perinatal or congenital hearing loss, compared with 532 healthy subjects and 404 patients with well-compensated chronic vestibular deficit (CVF). VSWM was evaluated by the eCorsi test. The subjects suffering from chronic hearing loss and/or unilateral or bilateral vestibular deficit showed a VSWM less efficient than healthy people, but much better than those with CVF, suggesting a better multimodal adaptive strategy, probably favored by a cross-modal plasticity which also provides habitual use of lip reading. The sport activity cancels the difference with healthy subjects. It is therefore evident that patients with this type of deficit since childhood should be supported and advised on a sport activity or repeated vestibular stimulation.

Efficacy of intergrating vestibular rehabilitation and cognitive behaviour therapy in persons with persistent dizziness in primary care- a study protocol for a randomised controlled trial

Background

Dizziness is a common complaint, and the symptom often persists, together with additional complaints. A treatment combining Vestibular Rehabilitation (VR) and Cognitive Behaviour Therapy (CBT) is suggested. However, further research is necessary to evaluate the efficacy of such an intervention. The objective of this paper is to present the design of a randomised controlled trial aiming at evaluating the efficacy of an integrated treatment of VR and CBT on dizziness, physical function, psychological complaints and quality of life in persons with persistent dizziness.

Methods/design

The randomised controlled trial is an assessor-blinded, block-randomised, parallel-group design, with a 6- and 12-month follow-up. The study includes 125 participants from Bergen (Norway) and surrounding areas. Included participants present with persistent dizziness lasting for at least 3 months, triggered or exacerbated by movement. All participants receive a one-session treatment (Brief Intervention Vestibular Rehabilitation; BI-VR) with VR before being randomised into a control group or an intervention group. The intervention group will further be offered an eight-session treatment integrating VR and CBT. The primary outcomes in the study are the Dizziness Handicap Inventory and preferred gait velocity.

Discussion

Previous studies combining these treatments have been of varying methodological quality, with small samples, and long-term effects have not been maintained. In addition, only the CBT has been administered in supervised sessions, with VR offered as home exercises. The current study focusses on the integrated treatment, a sufficiently powered sample size, and a standardised treatment programme evaluated by validated outcomes using a standardised assessment protocol.

Trial registration

www.clinicaltrials.gov, ID: NCT02655575. Registered on 14 January 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3660-5) contains supplementary material, which is available to authorized users.

Probing the role of the vestibular system in motivation and reward-based attention

The vestibular system has widespread connections in the central nervous system. Several activation loci following vestibular stimulations have been notably reported in deep, limbic areas that are otherwise difficult to reach and modulate in healthy subjects. Following preliminary evidence, suggesting that such stimulations might affect mood and affective processing, we wondered whether the vestibular system is also involved in motivation. Evolutionary accounts suggest that visuo-vestibular mismatches might have a role in preventing the search for and exploitation of goods that previously resulted in aversive reactions, as they would be a fine warning signal which follows the contact with or ingestion of noxious neurotoxins. The first question was thus whether vestibular stimulation alters sensitivity to reward. Secondly, we sought to assess whether attention is allocated in space differently when cued by highly motivational stimuli, and if this interplay is further modulated by the vestibular system. In order to evaluate both motivational and attentional assets, we administered a Posner-like cueing task to 30 healthy subjects concurrently receiving sham or galvanic vestibular stimulation (GVS; Left-Anodal and Right-Anodal configurations). The participants had to discriminate targets appearing in either exogenously cued or uncued locations (50% validity); cues predicted the amount of points (0, 2, or 10) and thus money that they could earn for a correct response. The results highlight a robust inhibition of return (IOR) (faster responses for invalidly-cued targets) which was not modulated by different levels of reward or GVS. Across all stimulation sessions, rewards exerted a powerful beneficial effect over performance: reaction times were faster when rewards were at stake. However, this effect was largest in sham, but greatly reduced in GVS conditions, most notably with the Right-Anodal configuration. This is the first evidence for a decreased sensitivity to rewards causally induced by a perturbation of the vestibular system. While future studies will shed light on its neural underpinnings and clinical implications, here we argue that GVS could be a safe and promising way to enrich our understanding of reward processes and eventually tackle the management of patients with aberrant sensitivity to rewards.

Implementation of Rocking Chair Therapy for Veterans in Residential Substance Use Disorder Treatment [Formula: see text]

BACKGROUND

Substance use disorder (SUD) and mental health diagnosis negatively affect Veteran homelessness.

OBJECTIVE

Assess the acceptance and feasibility of rocking chair therapy as a self-implemented intervention for mood and substance cravings.

PICOT

For homeless Veterans in SUD treatment, how does adding vestibular stimulation by use of a rocking chair compared with treatment as usual affect levels of anxiety and substance cravings?

RESULTS

Two significant findings were observed. First, a greater number of minutes spent rocking was associated with significantly greater scores on the Expectancy scale of the Alcohol Craving Questionnaire (ACQ; p = .05), suggesting participants experiencing higher urges and desires to drink rocked to self-soothe. Second, a significant association was observed between a greater number of minutes spent rocking and lower scores on the ACQ Purposefulness subscale ( p = .03), indicating greater time rocking was associated with fewer urges and desires that are connected with the intent and plan to drink.

CONCLUSION

Vestibular stimulation by rocking in a rocking chair may increase the ability to self-regulate mood and substance cravings, thereby potentially reducing risk of relapse and recurrent chronic homelessness.

Functional Brain Activation in Response to a Clinical Vestibular Test Correlates with Balance

The current study characterizes brain fMRI activation in response to two modes of vestibular stimulation: Skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either a vestibulo-spinal reflex [saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)], or an ocular muscle response [utricle-mediated ocular VEMP (oVEMP)]. Research suggests that the skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for subjects than the high decibel tones required to elicit VEMPs. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of brain activity. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that pneumatically powered skull taps would elicit a similar pattern of brain activity as shown in previous studies. Our results provide the first evidence of using pneumatically powered skull taps to elicit vestibular activity inside the MRI scanner. A conjunction analysis revealed that skull taps elicit overlapping activation with auditory tone bursts in the canonical vestibular cortical regions. Further, our postural control assessments revealed that greater amplitude of brain activation in response to vestibular stimulation was associated with better balance control for both techniques. Additionally, we found that skull taps elicit more robust vestibular activity compared to auditory tone bursts, with less reported aversive effects, highlighting the utility of this approach for future clinical and basic science research.

Quality-of-life for individuals with a vestibular impairment following an acquired brain injury (ABI); the clients' perspective

PRIMARY OBJECTIVE

To investigate how a vestibular deficit following an acquired brain injury (ABI) affects an individuals' quality-of-life.

RESEARCH DESIGN

A qualitative exploratory design.

PARTICIPANTS

Nine community dwelling individuals who experienced significant symptoms and limitations as a result of their vestibular deficits.

METHODS

The individuals participated in face-to-face interviews with open ended questions. Data was analysed initially using a case study research approach, exploring the experience for each individual and then cross-case analysis to determine common themes for the group with the assistance of nVivo 10 qualitative analysis software.

RESULTS

Thematic analysis determined four main themes arising from the interviews; (1) validation, (2) definitive diagnosis is more difficult amongst an array of ABI symptoms, (3) vestibular adaptation is more difficult in the presence of an ABI and (4) emotional and social.

CONCLUSION

Individuals who suffer a brain injury and experience vestibular symptoms as part of their overall presentation are not diagnosed in a timely manner, with individuals, their families, associates and even health professionals feeling uncertain of the legitimacy of their reported symptoms. It is important that all patients who experience an acquired brain injury are screened for vestibular impairment and, if necessary, receive vestibular rehabilitation including explanation and education.