The mechanisms of chronic dizziness in brain injury (MOCDIBI)
Research type
Research Study
Full title
Advancing Rehabilitation: Physiological, Psychological and Neuroimaging. Measures of Factors that Predispose, Promote, and Perpetuate Post-Traumatic Dizziness
IRAS ID
254188
Contact name
BM Seemungal
Contact email
Sponsor organisation
Imperial College London
Clinicaltrials.gov Identifier
Not applicable, Not applicable
Duration of Study in the UK
3 years, 1 months, 1 days
Research summary
Research Summary:
Traumatic brain injury (TBI) is common, e.g. sports or military injuries. Most TBIs are mild-moderate or mTBI (depending upon the criteria used). Patients with mTBI usually recover well, however between 10-20% have persisting symptoms (Katz, Cohen & Alexander, 2015). Vestibular symptoms including dizziness, imbalance and disorientation are common in these patients, however, the mechanisms mediating these symptoms are unclear. We will investigate the laboratory and clinical features – including behavioural, physiological and psychological variables and associated alterations in brain structure and function - that may predict chronic disability in mTBI patients.
Introduction:
Dizziness and imbalance are common in traumatic brain injury survivors resulting in significantly reduced return to work rates and increased risk of falls. This study investigated the factors associated with the onset and persisting dizziness and imbalance.Methods:
10 mild traumatic brain injury (mTBI) patients were recruited from St. Mary’s Hospital (London, UK) of which 9 patients consented to undergo laboratory testing and brain imaging. 37 healthy age-matched controls also completed laboratory testing to establish normative data.
Laboratory testing included assessments of vestibular perception using rotatory chair, balance assessments using posturography platform, video head impulse test (vHIT), subjective visual vertical testing (SVV), and dynamic visual acuity test. Patients also completed several subjective questionnaires to assess their subjective balance ability, cognitive function, and mental health.
Summary of results:
Results:
Patients’ average thresholds of vestibular perception (ability to perceive whole body motion) were 1.21 deg/s/s (SD: 1.39) with two patients having attenuated perception (1 with overt vestibular agnosia - significantly attenuated perception). Patients’ peripheral vestibular function tests were normal with an average gain of 1 on the vHIT test. SVV testing indicated -0.8 and 0.7 degrees of tilt in the left and right direction, respectively. Patients’ average scores on the Dizziness Handicap Inventory (DHI) questionnaire (assessing subjective balance) were 13.5 (SD: 3.42) and ACE-R (cognitive function) scores were 88.75 (SD: 12.42).
Conclusions:
Acutely, high subjective dizziness scores are uncommon in mTBI, likely due to patients' attenuated perception (vestibular agnosia). Peripheral vestibular testing was unremarkable.
From our findings, we hypothesise that, at least in mTBI, chronic subjective dizziness arises as a complex interaction between psychological/psychiatric disorders compounded by suboptimal medical management.Implications:
Vestibular agnosia can mask the subjective dizziness after injury leading to suboptimal medical management resulting in poor long-term outcomes for brain injury survivors. Complete objective vestibular assessment is key in addition to subjective reports from patients.Research Team:
Research was carried out at Imperial College London at the Centre for Vestibular Neurology under the supervision of Dr Barry Seemungal.Funding:
The study was funded by The US Department of Defense - Congressionally Directed Medical Research Program (CDMRP).REC name
Yorkshire & The Humber - Leeds East Research Ethics Committee
REC reference
19/YH/0051
Date of REC Opinion
7 Aug 2019
REC opinion
Further Information Favourable Opinion