Advances in the assessment and rehabilitation of people with chronic vestibular disorders

Student thesis: Doctoral ThesisDoctor of Philosophy


This PhD thesis focuses on the assessment and rehabilitation of people with a chronic vestibular disorder (CVD). Chapter 1 focuses on providing the background information on experimental chapters. Four experimental studies were conducted (Chapters 2-5). Two of these (Chapter 3 and 4) were on people with CVD. One study (Chapter 2) was an investigation on healthy adults which could provide normative data for comparisons to people with CVD and one (Chapter 5) on dizziness, unsteadiness and/or falls following the coronavirus-disease-19 (COVID-19) infection. Chapter 6 includes the general discussion on experimental Chapters 2-5 and their limitations including limitations related to COVID-19 outbreak.

In terms of the experimental studies, the first (Chapter 2) was a case-controlled study which aimed to investigate the factors that predicted Functional Gait Assessment (FGA) and FGA dual task (DT) gait performance in 100 healthy adults aged 18-80 years old. The results showed that the FGA performance scores were lower (i.e., worse) for FGA DT conditions versus FGA in isolation. The numeracy DT had the greatest impact on FGA performance followed by literacy and lastly, auditory DT. Younger age, higher level of formal education (LoE) and better performance on various cognitive function tasks including those assessing episodic memory, visual processing speed and divided attention, were the main predictors explaining 44-57% of the variance for better performance on all FGA conditions. Additionally, better hearing capacity was one of the predictors for better performance on FGA while lower scores on the questionnaire measuring daytime sleepiness predicted better performance on FGA with numeracy DT. For more than 35% of adults over 65 years old, numeracy and literacy DT resulted in increased falls risk as indicated by FGA scores. Gait performance in DT conditions is linked to increased falls risk and particularly in older adults. Balance assessments and intervention programs as well as community exercise classes should consider including a DT component for falls prevention.

Second study (Chapter 3) was a case-controlled study which aimed to identify the factors that predicted FGA and FGA DT gait performance in 48 people with CVD aged 18-80 years old. The findings showed that the type of DT condition significantly impacts FGA scores. Even in highly functional people with CVD with normative FGA scores, there is an indication of higher falls risk when a complex cognitive task is added during walking. Therefore, the vestibular rehabilitation (VRT) programs should consider including a customised DT component of appropriate complexity according to the person’s functional capacity and symptoms for balance training. Also, from predictive models for FGA and FGA DT performance which explained 42-50% of the variance for all FGA conditions, it appears that assessments of sleep, Body Mass Index (BMI), and physical activity (PA) levels should be offered if people have poor sleep or increased daytime sleepiness, abnormal (>25 BMI) or lower than recommended PA levels, respectively. Also, lower score for visually induced dizziness (ViD), predicted better performance on two out of four FGA conditions. Specific exercises to target ViD should be included in VRT programs which may help improving further gait and DT gait performance. Adding supervision and education to customised VRT may target more effectively these issues as well as people’s poor self-perceived balance confidence and improve better gait and ability to DT during walking, therefore, may decrease the overall falls risk.

Third study (Chapter 4) was a single-blinded pilot-parallel randomised controlled trial (RCT) which aimed to investigate the effect of a 12-week customised VRT program incorporating cognitive and auditory DT exercises on FGA and average FGA DT cost score (primary outcome) as well as subjective symptoms, cognitive function performance, anxiety, depression, and sleep (secondary outcomes) in 48 people with CVD aged 18-80 years old. The main findings indicated that both VRT with and without DT exercises help to improve subjective symptoms, balance, gait, and ability to DT in people with CVD. However, practising DT exercises in addition to a customised and supervised VRT program may provide a greater change in patients’ perceived handicap from dizziness, and ViD. Practising specific DT exercises may help to achieve average normative scores on FGA with simultaneous performance of a numeracy task which was the most challenging DT condition.

The last experiment of this thesis (Chapter 5) was developed because of the coronavirus-disease-2019 (COVID-19) outbreak in 2020 and the need to understand better the relationship of this disease with dizziness, unsteadiness, and/or falls as well as the clinical presentation and impact of these symptoms on people’s ability to perform activities of daily living (ADLs). This study (Chapter 5) was an online anonymous survey which aimed to investigate the prevalence, clinical presentation (e.g., self-reported) and impact of dizziness, unsteadiness and falls in adults over 18 years old who were positive for COVID-19. Results demonstrated that people affected by COVID-19 may experience new onset or exacerbation of previous symptoms of dizziness and unsteadiness and increased incidence of falls for over six months after the acute COVID-19 infection with a significant impact on their ability to perform ADLs and work. Following the acute COVID-19 infection, over 70% of respondents to the survey questionnaire reported experiencing dizziness, over 60% unsteadiness, and around 20% falls. Dizziness and unsteadiness should be recognised among symptoms in patient with symptoms experienced after the acute COVID-19 infection. People with lingering and persistent symptoms such as dizziness unsteadiness and/or falls following the acute COVID-19 infection, should be referred to appropriate health care providers for assessment and management of their symptoms. The findings of this survey may help to shed light into better understanding of the prevalence, clinical presentation and impact of dizziness, unsteadiness and/or falls in adults who were positive for COVID-19 and increase clinicians’ awareness who tend to see patients with such symptoms for assessment and intervention.

Date of Award1 May 2023
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorMarousa Pavlou (Supervisor) & Irene Di Giulio (Supervisor)

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