Ongoing research projects

Abstract

Visuospatial neglect (VSN) is a frequent post-stroke neuropsychological cognitive disorder which leaves patients with impaired or even lost awareness for stimuli and/or events on the contralesional hemispace.  VSN is reported to occur in 30-70% of right-brain strokes and 20-60% of left-brain strokes.

Although spontaneous neurological recovery of VSN occurs in most patients within the first 10-12 weeks post-stroke, 20-40% of patients with VSN still show symptoms a year-post stroke.  The latter might have important consequences, as VSN is negatively associated with the motor recovery of the upper limb and independence during activities of daily living (ADL).

Although recovery of gait is a primary goal within stroke rehabilitation, little is known about the impact of VSN on the true motor recovery of the lower limbs and on motor performance in general (as measured by gait, balance control and truncal function).  As this impact is still unknown, it is difficult for clinicians to provide accurate rehabilitation strategies.

Therefore, it is important to unravel the interaction between VSN on one hand and motor recovery and motor performance on the other hand.  This will give us more insights in the interplay between spatially-oriented cognitive processes and motor functioning, therefore providing a possible framework for the development of new innovative rehabilitation strategies.

The presence of an interaction between cognition (e.g. VSN) and motor function raises the question whether training one aspect can have carry-over effects to the other.  Consequently, a very relevant question is whether spatial retraining, designed to enhance VSN, can indirectly stimulate the recovery of motor function and performance as well.

In this project, we will address three main research objectives:

1) Investigating the impact of VSN on true motor recovery of the lower limbs;

2) Investigating the impact of VSN on motor performance as measured by gait, balance control, truncal function;

3) Investigating the carry-over effects of spatial retraining on true motor recovery of the lower limbs and motor performance.

Duration: 1/8/2018 - 1/8/2024

Researchers

• Promoter: Dr. Wim Saeys​
• Co-promoter: Prof. Dr. Steven Truijen, Prof. Dr. Christophe Lafosse​
  
• PhD Student: Elissa Embrechts​
  

Research Groups

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

Abstract

Pre-clinical research has pointed towards a time-limited period early after stroke during which most spontaneous and therapy-induced recovery is observed.  For example, training has led to substantial recovery if initiated 5 or 14, but not 30 days post-stroke in a rodent model.  It is suggested that this early period is characterized by heightened levels of neuroplastic repair and that rehabilitative training can exploit this leading to improved outcome.  Some evidence suggests that similar mechanisms are induced in the human brain after stroke, however clinical research on this is (disappointingly) sparse.

In a two-folded research project, we aim to longitudinally investigate the mechanisms underlying walking recovery and the responsiveness to training in terms of kinetics and muscle activity of standing balance and gait.  By that, we aim to detect a time window after stroke which resembles the same characteristics as those observed in animal stroke models.  To initiate training at an early stage, when patients usually present severe weakness and balance deficits, a recently developed mobile exoskeleton is used which is developed to provide intensive practice in ‘normal’ gait patterns.

This knowledge has the potential to change how rehabilitation is provided, as to date stroke patients spend most of their waking hours in rehabilitation facilities physically inactive.  Evidence on a “critical time window” will encourage a substantial shift towards a rehabilitation approach where patients are intensively stimulated to recover, for example by the use of robotic devices.

Duration: 01/01/2019 – 31/12/2022

Funding: JS is a SB PhD fellow (project nr.: 1S64819N) at the FWO, Research Foundation - Flanders, Belgium.

Researchers

• Supervisor: Prof. Dr. Steven Truijen (UA)
• Co-supervisor: Dr. Wim Saeys (UA)
• Co-supervisor: Prof. Dr. Laetitia Yperzeele (UA)
• External co-supervisor: Prof. Dr. Gert Kwakkel (VUMC, Amsterdam, NL)
• PhD Student: Jonas Schröder​

Research groups

Abstract

All of a sudden you feel light-headed, your vision gets blurry and all you want to do is grasp something to keep your balance…  Sounds familiar?  Almost everyone has experienced something like this, and that is completely normal.  Imagine, however, suffering through this several times a day, or even having to face it non-stop!  For some people, this is reality.  The above symptoms are united under the term ‘dizziness’, but as the symptoms are not objectively measurable, i.e. only a subjective perception, this list is non-exhaustive and can be expanded.  It is obvious that even the less pronounced cases of this chronic disease have an enormous impact on the person’s functioning in daily life, as well as their social interactions.

This study provides an in-depth look at two types of persistent or chronic dizziness, namely dizziness provoked by structures related to the neck, and dizziness triggered by visual stimuli.  The overall goal of this research is to define diagnostic criteria and treatment methods for both disease types.  In order to accomplish this, of all chronic dizzy patients, only those of whom the dizziness complaints can be linked to neck structures or provoking visual stimuli will be selected.  For these patients, the effectiveness of several treatment strategies will be evaluated.

Duration: 01/10/2018 - 30/09/2022

Researchers

• Promoter: Prof. Dr. Luc Vereeck​
• Co-promoters: Prof. Dr. Willem De Hertogh and Prof. Dr. Vincent Van Rompaey​
• PhD Student: Charlotte De Vestel​

Research department

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

Abstract

We are planning a large fMRI study investigating brain activity while altering the patient’s cervical somatosensory input.  To reach this goal, we need to change the cervical somatosensory input without moving the patient’s head, to enable simultaneous MRI scans.  Currently, the best investigated technique to change cervical somatosensory input is the application of vibration.  Lekhel et al. have demonstrated that application of vibration to the upper part of the trapezius muscle resulted in a forward deviation of the centre of pressure (CoP) during postural sway measurement in asymptomatic volunteers.  This deviation in CoP during postural sway measurement, is a proof that cervical somatosensory input is changed with the applied vibration.  A more recent study showed similar results using electro-tactile stimulation to influence cervical somatosensory input.

Off course, to apply such vibrations to patients in MRI scanners, is more challenging, as the used devices should be MRI compatible.  We will be using an existing micro piezo-tactile stimulator (mPTS) system to apply vibration to the cervical spine.  This system uses the piezoelectric effect to generate vibration by running electricity through quartz crystals, which makes them vibrate.

The mPTS system, manufactured by ‘Dancer Design’ in the UK (http://www.dancerdesign.co.uk/index.html), is specifically designed for use in an MRI scanner and is already available in our research group.  This system has been used in fMRI studies with other goals before.  The promotor of the project became acquainted with the mPTS during a research visit to the University of Nottingham, where she collaborated in an ongoing fMRI study with Dr. Jodie Davies-Thompson. This is where the idea of using the mPTS system to alter cervical somatosensory input originated.

A pilot test of the mPTS system in the manufacturer’s headquarters in Manchester, showed a clear change in cervical somatosensory input in 2 subjects.  Based on these preliminary data and the previous research from Lekhel et al. and De Nunzio et al. we can expect that the vibration of the mPTS will similarly influence the cervical somatosensory input in a larger population.  However, to use the system for the planned fMRI study, we need to define the best combination of vibration frequency and location to maximally alter the cervical somatosensory input.  Once this is known, we can start the fMRI study.

Duration: 01/11/2020 - 01/07/2021

Researchers

• Promoter: Prof. Dr. Willem De Hertogh​
• Co-Promoter: Prof. Dr. Sarah Michiels​
• PhD Student: Antonios Chalimourdas​

Research Groups

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

Abstract

After experiencing a sudden partial or complete loss of function of one of both vestibular organs - or an acute unilateral vestibular deafferentiation (uVD) syndrome - the patient suffers from following symptoms: vertigo, instability, nausea and nystagmus.  In many patients with an acute uVD syndrome symptoms are expected to resolve spontaneously because of central compensation.  However, more detailed observations have revealed that 29-66 % of uVD patients develop disabling chronic dizziness lasting >1 year after the acute event. Identifying predictors of chronic dizziness would allow patients at high risk to be targeted with personalized therapies to reduce healthcare costs.  Therefore, the main objective of this study is to identify predictors of chronic dizziness after an acute uVD.  During a 2-year prospective cohort study 200 patients with an acute uVD syndrome will be included and seen 5 times.  Specific risk factors will then be studied such as central compensation, visual dependency, level of physical activity and anxiety and avoidance behavior.  Afterwards the effect of these risk factors on chronicity will be analysed.

Duration: 01/11/2020 – 31/10/2024

Researchers

• Promoter: Prof. Dr. Luc Vereeck​
• Promoter: Prof. Dr. Ann Hallemans​
• Promoter: Prof. Dr. Vincent Van Rompaey​
• PhD Student: Lien Van Laer​

Research groups

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

Abstract

Worldwide, Developmental Coordination Disorder (DCD) accounts for 5-6% of the school-aged children showing a motor delay early in childhood.  Poor balance control is the most significant motor problem occurring in 73-87% of the children with DCD.  These balance deficits severely affect daily functioning, but underlying control mechanisms are still poorly understood.  Therefore, the main aim of this project is understanding the heterogeneity of DCD by studying balance performance, its control mechanisms and its impact on motor performance.  Based on functional performance and neuroimaging data it is hypothesized that balance performance and control of children with DCD can be situated on a continuum between cerebral palsy (CP) and typically developing children (TDC).  As such a case-control study will be performed comparing balance performance, motor performance, cortical brain activity and muscular activation patterns in children with DCD to children with CP and TDC.  The novelty of this study lies in the synergistic approach of combining functional assessments with brain imaging and neuromechanical analysis.  This approach is a major step forward in unraveling the interplay between the control system (brain and the rest of the nervous system) and the effector system (musculoskeletal system).  It can provide groundbreaking insights into the heterogeneity of DCD as well as a better understanding of the relationship between balance and motor performance.

Duration: 01/01/2021 - --/--/20--

Researchers

• Promoter: Prof. Dr. Ann Hallemans (UAntwerpen)
• Co-promoter: Prof. Dr. An Boudewyns (UAntwerpen/UZA)
• External co-promoter: Dr. Evi Verbecque (UAntwerpen/UHasselt)
• PhD Student: Charlotte Johnson (UAntwerpen)

Research groups

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

Abstract

Cerebral Palsy (CP), induced by non-progressive damages in the immature brain (in 1.5 to 2.5 in 1000 life births), is characterized by abnormal postures and movements.  Poor balance is one of the most significant motor problems in children with CP, which severely affect everyday functionalities such as sitting, standing, walking and running. However, up to know, the underlying causes of poor balance in CP remain understood.  This incomplete understanding may be associated to the mixed results in effectiveness of balance training programs for children with CP.

Proprioception (or in other words, the perception of our body movements and position in space) is a key determinant acting in balance control.  Research has shown that about 44% - 72% of the children with CP have marked proprioceptive deficits in the upper limbs. Whereas the relationship between upper limb proprioception and uni-/bimanual function is clear in CP, lower limb proprioception (at different joints; hip, knee and ankle) and the role in balance is much less understood.  Therefore, the main aim of this project is understanding the proprioceptive sense in children with CP by clarifying 1) to what extent a proprioception deficit affects a child with CP, globally or locally, and 2) to what extent a proprioception deficit contributes to balance control in CP.

In a 4-year research project, a cross-sectional case-control will be conducted comparing proprioception and balance performance in children with CP to age-matched typically developing children.  The novelty of this project lies in the comprehensive assessment of proprioception of multiple joints (upper and lower limb), using the Vicon 3D motion capture system^©, and its association with balance performance regarding different balance domains.  This in-depth knowledge will provide novel insights in the causes of poor balance control in CP, enhancing individualised therapeutic plans for balance training. In the last project phase, a proprioception training program will be developed together with a feasibility study on the implementation of this training to improve proprioception and balance in children with CP.

Duration: 01/09/2020 - 01/09/2024

Researchers

• Supervisor: Prof. Dr. Pieter Meyns (UHasselt)
• Co-supervisor: Prof. Dr. Ann Hallemans (UAntwerpen)
• Co-supervisor: Prof. Dr. Guy Molenaers (KULeuven)
• PhD Student: Nina Jacobs​

Research groups

Abstract

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in the world and affects an estimated 6.2 million people worldwide.  This figure is expected to double by 2040.  The disease is hallmarked by classical motor symptoms such as tremor, rigidity and bradykinesia as well as non-motor signs.  Neuropsychiatric signs are common non-motor symptoms and range from anxiety and dopamine dysregulation to apathy.  Motor and non-motor signs are often considered different manifestations of the same disease, however there may be common (yet unexplored) ground.  Apathetic PD patients suffer worse motor impairment than their non-apathetic peers.  This difference is even at diagnosis noticeable, with de novo PD patients scoring higher on the MDS-UPDRS.  Additionally, they are at increased risk of developing motor complications during follow up.  Postural instability, a common late-stage motor sign in PD, is found more often in this group as well.  These findings hint at a possibly more severe motor phenotype in this patient group.

Our study wants to examine the relationship between apathy and motor symptoms in PD.  The aim of our study is to determine whether certain patients, suffering from neuropsychiatric signs such as apathy, present a different motor phenotype from their non-apathetic peers. We examine this by collecting data on patients’ gait, more specifically the presence of axial rigidity as well as possible gait initiation problems.  With our research we aim to bridge the divide between motor and non-motor symptoms in PD and pave the way for patient-tailored therapy.

Duration: 1/10/2019 - 31/09/2023

Researchers

• Promoter: Prof. Dr. Patrick Cras​
  
• Co-promoter: Prof. Dr. David Crosiers​ 
  
• Co-promoter: Prof. Dr. Ann Hallemans 
  
• PhD Student: Ségolène De Waele​

Research groups

University of Antwerp, department of Rehabilitation Sciences and Physiotherapy

University of Antwerp, department of Translational Neurosciences

Abstract

Falls in older adults pose a major public health burden worldwide. They have consequences on a personal level, both physical and psychological, as well as on a societal level such as increased financial costs and pressure on our healthcare system. Difficulties with balance and walking are major risk factors and causes of falls in older adults. Functional balance control in humans is governed by the integration of mainly somatosensory, visual and vestibular input who inform the brain about any balance disturbances. The brain hereupon reacts by sending out motor commands to our musculoskeletal system to adequately react to balance disturbances. With ageing, the quality of afferent information from these three sensory systems decreases. Because of this, adaptive balance strategies, crucial for responding to disturbances, might deteriorate, putting older adults at risk for a fall. In an everyday life context, we very often perform head movements while standing or walking, e.g. when scanning for products at the grocery store or checking the environment before crossing the street. Especially in older adults these routine head movements can intrusively perturb our balance and sensory systems (neck somatosensation, visual & vestibular system). Surprisingly, while research shows each of these systems impact fall risk, comprehensive studies simultaneously correlating these sensory systems with balance strategies, gait, and falling in older adults remain lacking.

The overarching aim of this  four year doctoral study is to analyse gait and balance strategies in older adults through head-motion perturbed standing and walking with integration of sensory function and frailty. The project encompasses two main experimental design studies. Firstly, a cross-sectional study in healthy young adults employing a novel biomechanical movement analysis protocol with usage of augmented reality. Secondly, a case-control study comparing gait, balance, sensory function and frailty in a sample of older adults with and without fall history.

Duration: 01/10/2022 – 01/10/2026

Researchers

Promotors: prof. dr. Ann Hallemans, prof. dr. Willem De Hertogh, prof. dr. David Beckwée​

Supervisor: prof. dr. Luc Vereeck​

PhD Student: Eugénie Lambrecht​

Research groups

University of Antwerp, MOVANT (Movement Antwerp), department of Rehabilitation Sciences and Physiotherapy