Pain, Fatigue & Persistent Somatic Symptoms
Chronic fatigue syndrome, medically unexplained physical complaints, fatigue in people with multiple sclerosis, pain in people with multiple sclerosis and low back pain & neck pain.
Functional Syndromes: Interoception, Proprioception, and Chronic Fatigue Syndrome
Somatically Unexplained Physical Complaints — physical complaints that cannot be adequately explained by a diagnosed organic disease — represent a significant issue within healthcare. These complaints can vary widely (including headaches, digestive issues, fatigue, muscle pain, breathlessness, etc.) and can lead to severe functional limitations. SOLK can manifest as transient singular complaints, occur within the context of stress-related disorders such as overstress and burnout, or take on a chronic form, as seen in functional syndromes (e.g., chronic fatigue syndrome, fibromyalgia, chronic whiplash syndrome). The known high prevalence of SOLK is associated with substantial societal costs.
A narrow biomedical disease model fails to acknowledge that self-reported health complaints are always the result of a complex integration in the brain of afferent signals from the body (bottom-up) and perceptual-cognitive and affective processes (top-down). Integrating findings from interoception and symptom perception research with stress physiology and neurobiological data allows us to transcend dualistic thinking (either psychological or physical). Our research group aims to contribute to the further identification of the underlying mechanisms of SOLK and translate this knowledge into concrete treatment components.
Project 1:
Identification of (Psycho)physiologically Based Subgroups in Chronic Fatigue Syndrome and Their Relevance for Rehabilitation (R-11754)
Promoters: Katleen Bogaerts (UHasselt) and Lukas Van Oudenhove (KULeuven)
FWO Junior Research Grant: G057921N
Approximately 20,000 people in Belgium suffer from chronic fatigue syndrome (CFS), a condition characterized by persistent fatigue that cannot be adequately explained by medical or psychiatric disorders. Research has demonstrated dysfunctions in various (psycho)physiological systems in CFS, including the stress response system, immune system, and central nervous system (e.g., neuroinflammation and changes in functional connectivity in the brain). Conversely, health psychology research has shown disruptions in symptom perception among CFS patients. However, these two lines of research are insufficiently integrated, which is necessary to overcome dualistic debates that have hindered progress in understanding and treating CFS. Specifically, it remains unclear how the aforementioned dysfunctions relate to symptom perception among CFS patients, particularly regarding the perception of physical and mental fatigue. The goal of this FWO project is to investigate the complex relationships between fatigue perception and various psychophysiological dysfunctions in CFS patients, identify subgroups based on these dysfunctions, and link them to rehabilitation success. This is urgently needed to develop a refined integrative pathophysiological model of this serious but poorly understood condition, for which treatment options are currently limited.
Project 2:
The hypothesis is that dysregulated stress physiology and inadequate interoceptive processes play a crucial role in the development and persistence of Somatically Unexplained Physical Complaints (SOLK). In our studies, we aim to examine the autonomic stress physiology (breathing, heart rate, muscle tension, peripheral skin temperature, and skin conductance) and interoceptive skills (accuracy, sensitivity, and awareness) of individuals with stress-related and/or functional physical complaints [overstress, burnout, and functional somatic syndromes (FSS)]. The effect of a brief interoceptive training on interoceptive accuracy in an FSS population will also be investigated. Furthermore, a new, broader definition of interoception includes all afferent information originating from the body, including proprioception. Therefore, we seek to translate the interoceptive theoretical framework into a proprioceptive framework. This will involve developing a new measure for proprioceptive accuracy and validating a proprioceptive sensitivity questionnaire. In a follow-up study, we will map both interoceptive and proprioceptive skills in FSS patients. Lastly, we will further explore personal characteristics such as "need for control" as potentially influential factors, with the ultimate goal of validating the "Need for Controllability and Predictability Questionnaire" (NCP-q) within a SOLK population.
Project 3:
Symptom Perception as a Transdiagnostic Underlying Mechanism for Functional Syndromes
ESR 1 Tara Petske: (Co-)Promoters: Michael Witthöft, Johannes Gutenberg-University, Mainz, Germany; Katleen Bogaerts, Hasselt University, University of Leuven, Tumi Therapeutics, Belgium; Ferenc Köteles, Eötvös Lorànd University, Budapest, Hungary; Nadine Lehnen, Technische Universität München, Germany (including a 4-month work visit at Tumi Therapeutics, MOU L-654 – acquiring knowledge about translation from scientific results to clinical services).
The main objective of this project is to investigate whether changes in the perception of bodily signals (i.e., interoception) and dysregulated emotion regulation are causally related to the experience of complaints in functional syndromes. ESR1 will explore interoception (i.e., interoceptive accuracy measured through heartbeat mental tracking tasks and signal detection tasks) and emotion regulation (i.e., reappraisal, expressive suppression, regulatory choice) among individuals at risk of developing functional syndromes (versus a healthy control group). Identified changes in interoception and emotion regulation will be actively manipulated using training protocols to investigate their causal role in triggering and influencing physical complaints.
This project is part of the H2020 project Marie Sklodowska-Curie Research Training Group “INT ETUDE” (01/01/2021 – 31/12/2024; dossier number: 956673). Within "Encompassing Training in Functional Disorders across Europe" (ETUDE), 30 European expert groups collaborate on (1) scientific research and clinical translation regarding diagnostics, treatment, and communication in functional disorders (FD), as well as (2) training the next generation of multidisciplinary experts within an international PhD training program. The ETUDE program will contribute to identifying underlying mechanisms, optimizing diagnostics and treatment, and reducing stigma among FD patients.
Katleen Bogaerts
Pain & Fatigue in Individuals with Multiple Sclerosis
Reliability of Outcome Measures for Pain in Multiple Sclerosis.
Pain is a significant symptom in multiple sclerosis (MS), leading to a low quality of life, increased disability, work absenteeism, and mental health issues. People with MS frequently report pain as one of the most distressing symptoms of their condition. Unlike other neurological disorders, MS involves a wide variety of pain types, and pain has a greater impact on the daily lives of MS patients.
The prevalence of pain in MS varies from 29% to 86%. However, very few pain outcome measures have been validated specifically for the MS population. Existing instruments used in studies involving MS include the Neuropathic Pain Scale, the Brief Pain Inventory, the Graded Chronic Pain Scale, and the Medical Outcomes Study Pain Effects Scale.
Despite their use, these measures have not been tested for test-retest reliability in the MS population, leaving unclear what measurement errors may occur when applied at different testing intervals. Additionally, the concurrent validity of various instruments remains unknown, and no comparisons have been made with gold standards from other pain research. Therefore, the aim of the current project proposal is to investigate the test-retest reliability over days (variability) and the concurrent validity of a range of pain outcome measures in individuals with MS.
Effects of Fatigue Protocols on Cognitive-Motor Dual-Task Performance in MS.
Many daily activities involve performing a motor and cognitive task simultaneously, such as walking while conversing with a partner. Cognitive-motor interference (CMI), defined as reduced performance due to the simultaneous execution of tasks and quantified by dual-task costs (DTC), serves as an ecologically valid measure of limitations in daily living. Individuals with MS experience a wide variety of symptoms, including fatigue and fatigability, which can impact their walking and dual-task performance in daily life.
To our knowledge, the effects of an operationalized task that induces fatigue on dual-task performance have not yet been studied in the MS population. This study aims to explore the effects of a fatiguing motor task on dual-task performance among individuals with MS and consists of two work packages (WPs).
- WP1: A systematic review of the effects of induced fatigue (fatigability) on gait, balance, and dual-task performance in older adults and individuals with neurological conditions is planned.
- WP2: This involves a large cross-sectional study examining the effects of motor fatigability on dual-task performance in individuals with MS. The study will take place in Belgium, Turkey, Israel, Spain, and Chile and is supported by the European Network for MS Rehabilitation and Research (RIMS).
Walking Fatigability in Individuals with MS.
Fatigability is defined as a change in performance over time according to tasks and situations. Preliminary research from our team has shown that individuals with MS experience a significant decrease in movement amplitude during a coordination task of the lower limbs while seated when they have walking fatigability. A pilot study conducted by our research group demonstrated that dance therapy significantly improved fatigue impact. However, the effect of dance therapy on performance fatigability remains unknown.
The primary objective of this research is to investigate the reliability of a lower limb coordination task and cognitive fatigue measurement. Additionally, we aim to assess the impact of an eight-week choreo-based dance intervention on fatigue and fatigability in individuals with MS through a randomized controlled pilot study. Thirty persons with MS (pwMS) will be assigned to either a dance group or a control group focused on stretching and balance exercises. Clinical coordination parameters will be collected at baseline and post-intervention.
This project is supported by the MS League of Flanders and the Claire Fouconnier Fund (King Baudouin Foundation).
Peter Feys
Ilse Lamers
Fatigue in children with cerebral palsy
Balance problems during standing and walking are crucial issues in children with cerebral palsy (CP). Although balance problems have been increasingly recognized in recent decades, the underlying causes for poorer balance performance remain unclear. This consequently leads to mixed results regarding the effects of various balance training programs.
At the peripheral level, prolonged physical activity can increase balance problems due to muscle fatigue. Since muscle fatigue is a frequent complaint in CP, balance problems may also occur as a result of physical exertion. Therefore, the main goal of this project is to gain insight into this underexplored, but likely very relevant, peripheral determinant for the balance problems in children with CP.
Pieter Meyns
Low back pain
Hyperventilation and non-specific low back pain
Low back pain (LBP) is the leading cause of disability worldwide. Impaired postural control is a key factor in the development and maintenance of LBP. Moreover, the prevalence of LBP is associated with impairments in diaphragm function, symptoms of dyspnoea, and dysfunctional breathing. However, the association between LBP (and more specifically postural control) and hyperventilation remains unknown. The main objective of this project is to investigate whether the presence of recurrent non-specific LBP is related to the presence of hyperventilation, when classified either objectively by decreased CO2 values (demonstrating hypocapnia) or by symptoms while showing normal CO2 values.
Moreover, we will explore whether psychosocial factors play a role in this relation. Subsequently, we will investigate whether hyperventilation in LBP patients is related to impaired postural control, and more specifically to a decreased postural contribution of the diaphragm. Finally, we will investigate whether impaired postural control and hyperventilation in LBP patients can be improved by a targeted breath-controlling intervention.
This project will provide the first complete overview of the association between LBP and hyperventilation, which is essential for highlighting crucial and (potentially) reversible factors in the aetiology of LBP.
The associated role of lumbar proprioceptive deficits and psychosocial factors in pregnancy-related pelvic girdle pain: a longitudinal follow-up study in multiparous women (the PROFit study)
Low back pain, an extremely common symptom and the main cause of disability worldwide, affects women more than men. The increased prevalence in women is often accumulated by the high prevalence of pregnancy-related low back pain (PLBP). Up to 86% of pregnant women develop PLBP, with more than 50% reporting recurrences during subsequent pregnancies, and 10% experiencing serious consequences that persist for several years postpartum. To efficiently prevent (recurrences of) PLBP and to reduce negative long-term effects on maternal health, more research into the underlying mechanisms of PLBP is urgently needed.
Alterations in standing postural control have been observed frequently in the general population with LBP independent of pregnancy. Moreover, women with persistent PLBP postpartum more often report disturbances in body perception and fear of movement, factors previously linked to persistent LBP in the general population. However, alterations in proprioception, a primary sense for postural control, and body perception, and the association with PLBP have not been investigated yet during pregnancy and postpartum.
Therefore, this project will study whether changes in proprioception related to postural control, body perception, and fear of movement are predictive for developing persistent PLBP during pregnancy and postpartum. These findings will be used to optimize preventative and curative strategies for PLBP and to improve maternal health.
This study is funded by AXA Research Fund and by FWO ( G0A1N24N).
The Breathe-(H)IT trial: Multimodal high-intensity training to improve diaphragm function in persons with chronic nonspecific low back pain.
Chronic nonspecific low back pain (CNSLBP) is associated with impaired (breathing and postural)diaphragm function. International guidelines recommend exercise therapy as the first-choice treatment for CNSLBP. Exercise intensity is crucial in determining the effectiveness of exercise therapy, as high-intensity training (HIT) has been shown to be more effective than low- or moderate intensity training (MIT). Indeed, high-intensity inspiratory muscle training has been shown to improve diaphragm function and its relation to postural control more than low-intensity inspiratory, muscle training in persons with CNSLBP. However, inspiratory muscle training has no effect on disability, limiting its clinical applicability.
On the other hand, multimodal (total body) HIT does improve disability and cardiorespiratory fitness more than multimodal MIT. However, the working mechanisms for the added value of HIT remain largely unknown. One mechanism could be that HIT improves the diaphragm function, which plays key roles in breathing as well as postural control.
Therefore, we will perform an RCT with a long-term follow-up to investigate the effects of multimodal HIT compared to multimodal MIT on diaphragm strength, endurance, fatigue, and activation during postural control in persons with CNSLBP. Moreover, we will study whether the changes in diaphragm function after HIT correlate to changes in cardiorespiratory fitness, postural control, pain, disability, anxiety and depression.
Pre- and postoperative rehabilitation for patients undergoing single or double-level lumbar fusion for degenerative conditions
Lumbar fusion shows an international rising trend. Despite high fusion rates of more than 80%, approximately 40% of patients report suboptimal functional recovery and postoperative return to work is
underwhelming, thereby further increase the socio-economic impact.
This draws the attention towards rehabilitation in both the pre- and postoperative period. To date, high variability exists among health care providers in availability and content of rehabilitation, reflecting
the lack of scientific consensus.
The present research proposal seeks to address this need for consensus, by 1) developing a perioperative rehabilitation program for single- and double level lumbar fusion for degenerative conditions, that is endorsed by stakeholders and 2) evaluate the effectiveness of this rehabilitation program to improve important
outcomes for patients and our society.
This study is funded by FWO (1181521N).
Lotte Janssens
Katleen Bogaerts
Kenneth Verboven
Annick Timmermans
Degenerative hip and knee disorders
Abstract research project degenerative hip disorders
Osteoarthritis (OA) is one of the leading causes of pain and disability worldwide, and the hip joint is clinically one of the most affected locations of OA. The global prevalence and incidence of hip OA are expected to increase considerably in the upcoming decades, as a result of the aging population and an increasing prevalence of risk factors such as obesity and sedentary lifestyle. This raise will be accompanied with an increase in personal, financial, healthcare, and societal burden, as hip OA accounts for a large number of years lived with disability.
Large heterogeneity exists in the structural and clinical manifestation of hip OA, and persons with hip
OA exhibit different biopsychosocial characteristics. In order to unravel the complex and heterogeneous nature of hip OA, this research project aims to identify clinical phenotypes in persons with hip osteoarthritis, based on a set of biopsychosocial characteristics. The identification of distinct subgroups within the hip OA population might offer a foundation for individualized care pathways, with potential improvement of clinical outcomes.
Correspondingly with the increasing prevalence and incidence of hip OA, the mean utilization rate of hip arthroplasties is expected to increase considerably in the upcoming decades. Total hip arthroplasty (THA) is a cost-effective procedure in persons with hip OA. However, previous studies have reported that 8% of patients is dissatisfied with the outcome, and up to 23% of patients report long-term pain after THA. Furthermore, about 25% of patients report activity limitations and participation restrictions after THA. An important step towards understanding and improving outcomes after THA is prognostic factor research.
Knowledge of prognostic factors enables healthcare providers to identify persons at risk of poor outcome, and consequently increases options for shared decision making, expectation management and stratified care. Research suggests that the difference in outcome after THA cannot be entirely explained by structural factors or the surgery itself. Our research aims to unravel the prognostic role of biopsychosocial factors, including childhood trauma, mental disorders, and somatosensory function, on outcomes related to pain and disability after THA in persons with hip OA.
Annick Timmermans
Fatigue in post-COVID-19 condition
This observational study - in collaboration with KULeuven - has been set up to give us more insight into the functioning (and possible dysfunctions) of patients with long-lasting complaints after COVID-19 and to investigate the severity of fatigue in this population. The information we can obtain through a meticulous cognitive, mental, and physical examination will help us determine the right points of intervention for rehabilitation programs and provide information for the formulation of future (interventional) studies regarding multidisciplinary treatment of patients with long-lasting complaints after COVID-19.
PuRe COVID: lung rehabilitation in primary care for patients with long-lasting complaints after COVID-19
Chris Burtin
Tinnitus
Tinnitus is the perception of sound in the absence of an external source for the sound. It is a common symptom that affects 10 to 15% of the adult population, causing mood changes, anxiety, depression, sleep disorders, concentration problems and other psychological/emotional issues leading to severe disruptions of the quality of life. Tinnitus does not represent a disease itself but instead is a symptom of a variety of possible underlying diseases or malfunctions making the tinnitus population very heterogeneous.
Apart from well-known causes of tinnitus such as hearing loss and noise trauma, in 25% of patients, tinnitus is influenced by neck or jaw dysfunctions. These patients with so called somatic or somatosensory tinnitus are our main research population.
Studies in this population comprise clinical trials investigating the effectiveness and cost-effectiveness of musculoskeletal treatment and technology-based treatment options. An example is the FWO-funded study: The CATT trial.
In addition, research on somatic tinnitus diagnostics is being performed and more fundamental studies are being set up on brain changes in this population. For the latter we collaborate with colleagues from the neurological rehabilitation research domain.
Apart from specific somatic tinnitus research we also investigate the effect of movement and physical training on tinnitus complaints in general. For this study we collaborate with the colleagues from the cardiac rehabilitation research domain.