Exercise as Treatment of Fatigue in Parkinson's Disease (NCT06324422)

Exercise as Treatment of Fatigue in Parkinson's Disease (NCT06324422)

Fatigue is one of the most common and disabling non-motor symptoms of Parkinson's disease, affecting up to 70% of patients, yet pharmacological treatment options remain limited. This clinical trial investigates whether structured exercise interventions can effectively reduce fatigue and improve quality of life in people with Parkinson's disease.

Trial Overview

| Field | Value |
|-------|-------|
| NCT ID | NCT06324422 |
| Status | Recruiting |
| Phase | Not Applicable |
| Sponsor | University of Aarhus |
| Enrollment | 94 participants |
| Start Date | January 2024 |
| Completion Date | December 2025 |

Study Design

This prospective cohort study evaluates the effectiveness of structured exercise interventions in treating Parkinson's Disease-related fatigue. Unlike general tiredness, Parkinson's disease fatigue (PDF) is a distinct phenomenon characterized by disproportionate exhaustion relative to activity level, failure to complete tasks due to premature tiredness, morning fatigue that persists regardless of rest, and physical and mental components that compound each other. The trial employs a structured exercise program typically including aerobic training such as walking or cycling, resistance training, balance exercises, and flexibility and stretching routines.

Pathophysiology of Fatigue in Parkinson's Disease

Central Mechanisms

Exercise as Treatment of Fatigue in Parkinson's Disease (NCT06324422)

Fatigue is one of the most common and disabling non-motor symptoms of Parkinson's disease, affecting up to 70% of patients, yet pharmacological treatment options remain limited. This clinical trial investigates whether structured exercise interventions can effectively reduce fatigue and improve quality of life in people with Parkinson's disease.

Trial Overview

| Field | Value |
|-------|-------|
| NCT ID | NCT06324422 |
| Status | Recruiting |
| Phase | Not Applicable |
| Sponsor | University of Aarhus |
| Enrollment | 94 participants |
| Start Date | January 2024 |
| Completion Date | December 2025 |

Study Design

This prospective cohort study evaluates the effectiveness of structured exercise interventions in treating Parkinson's Disease-related fatigue. Unlike general tiredness, Parkinson's disease fatigue (PDF) is a distinct phenomenon characterized by disproportionate exhaustion relative to activity level, failure to complete tasks due to premature tiredness, morning fatigue that persists regardless of rest, and physical and mental components that compound each other. The trial employs a structured exercise program typically including aerobic training such as walking or cycling, resistance training, balance exercises, and flexibility and stretching routines.

Pathophysiology of Fatigue in Parkinson's Disease

Central Mechanisms

Fatigue in PD involves multiple overlapping pathophysiological mechanisms. Dopaminergic dysfunction results from loss of dopaminergic neurons in the substantia nigra, which affects motor planning and execution and requires greater cognitive effort for movements that become automatic in healthy individuals, contributing to perceived fatigue. Beyond dopamine, PD involves dysfunction in serotonergic systems affecting mood and energy regulation, noradrenergic systems affecting arousal and alertness, and acetylcholine affecting attention and muscle function. Neuroinflammation involving microglial activation and elevated cytokines including IL-1β, TNF-α, and IL-6 contributes to fatigue through direct effects on brain energy metabolism, altered hypothalamic-pituitary-adrenal axis function, and sleep disturbance amplification. Functional imaging studies show altered activity in the prefrontal cortex affecting executive function and task planning, the anterior cingulate cortex affecting attention and effort allocation, and the basal ganglia affecting motor automaticity.

Peripheral Mechanisms

Muscle abnormalities in PD include reduced mitochondrial function in skeletal muscle, altered muscle fiber type distribution, and impaired calcium handling. Cardiovascular dysregulation manifests as orthostatic hypotension, reduced baroreflex sensitivity, and impaired heart rate variability. Sleep fragmentation related to REM sleep behavior disorder, periodic limb movements, and nocturnal akinesia further compounds fatigue symptoms.

Exercise as Therapeutic Intervention

Neurobiological Mechanisms

Exercise benefits PD fatigue through multiple pathways. Regarding dopaminergic effects, exercise increases Brain-Derived Neurotrophic Factor (BDNF), which promotes survival of remaining dopaminergic neurons, enhances synaptic plasticity in motor circuits, and improves dopamine release and reuptake dynamics. Additionally, exercise may enhance tyrosine hydroxylase activity as the rate-limiting step in dopamine synthesis, vesicular monoamine transporter 2 function, and dopamine receptor sensitivity. Regular exercise exerts systemic anti-inflammatory effects including reduced circulating pro-inflammatory cytokines, increased anti-inflammatory cytokines such as IL-10, improved gut microbiome diversity reducing systemic inflammation, and enhanced lymphatic clearance of brain metabolites.

Regarding mitochondrial biogenesis, exercise stimulates PGC-1α activation as the master regulator of mitochondrial biogenesis, increases mitochondrial density in muscle and brain, enhances ATP production efficiency, and reduces oxidative stress markers. Aerobic exercise also improves cerebrovascular reactivity, endothelial function, angiogenesis in brain tissue, and clearance of metabolic waste via the glymphatic system.

Exercise Prescription Guidelines

The trial likely follows evidence-based exercise recommendations for PD, with the following components: aerobic exercise at 30 minutes moderate-intensity performed 3-5 times per week; resistance training with 8-10 exercises and 2-3 sets performed 2-3 times per week; balance exercises incorporating standing tasks and dual-tasking performed daily; flexibility with stretching major muscle groups performed daily; and gait training using treadmill or overground practice performed 3 times per week. Moderate intensity targets 40-70% heart rate reserve, or a Rating of Perceived Exertion of 12-14 on the Borg Scale.

Outcome Measures

Primary Outcomes

The Fatigue Severity Scale (FSS) is a 9-item questionnaire assessing the impact of fatigue on daily functioning. Scores range from 9 indicating no fatigue impact to 63 indicating severe fatigue impact, with a score ≥4 indicating clinically significant fatigue and a minimally important difference of 0.5-1.0 points per item. The Parkinson Fatigue Scale (PFS) is a PD-specific fatigue measure with 16 items covering physical and mental fatigue, with scores converted to a 0-100 scale where higher scores indicate greater fatigue.

Secondary Outcomes

The 6-Minute Walk Test measures functional exercise capacity, with normative values exceeding 450 meters for healthy adults over 60 years while PD values typically range from 300-400 meters, with improvements of 30-50 meters being clinically meaningful. The Parkinson's Disease Questionnaire-39 (PDQ-39) assesses quality of life across 8 domains including mobility, activities of daily living, emotional well-being, stigma, social support, cognitions, communication, and bodily discomfort, each scored on a 0-100 scale. The Epworth Sleepiness Scale measures daytime sleepiness with scores ranging from 0-24, where a score exceeding 10 indicates excessive daytime sleepiness, which is common in PD due to sleep fragmentation. The Beck Depression Inventory screens for depression with 21 items scoring 0-63, as depression and fatigue often co-occur in PD.

Clinical Significance

Current Treatment Landscape

Pharmacological options for PD fatigue are limited. Modafinil has mixed evidence and is not FDA-approved for PD fatigue. Methylphenidate may improve fatigue but has abuse potential. Dopamine agonists may help some patients but can worsen fatigue in others. Antidepressants may help if depression contributes. This creates a significant treatment gap that exercise can address.

Broader Health Benefits

Beyond fatigue, exercise provides multiple benefits for individuals with PD. Motor symptoms improve through slowed progression and improved mobility. Non-motor symptoms including sleep, mood, and cognition also benefit. Cardiovascular health improves through reduced cardiovascular mortality. Bone health benefits from osteoporosis prevention. Fall prevention improves through better balance and strength. Social engagement increases through group exercise reducing isolation.

Implementation Challenges

Key barriers to exercise in PD include fatigue itself creating a cycle of inactivity leading to deconditioning and more fatigue, motor fluctuations between "on" and "off" periods, freezing of gait, orthostatic hypotension, fear of falling, and limited access to specialized exercise programs.

Inclusion Criteria

Participants must be aged 40-80 years with a Parkinson's Disease diagnosis confirmed using UK Brain Bank criteria or equivalent. They must have clinically significant fatigue as indicated by a Fatigue Severity Scale score ≥4, be able to perform exercise safely, and have stable PD medication with no changes in the past 4 weeks.

Exclusion Criteria

Exclusion criteria include severe cardiovascular disease such as unstable angina, recent MI, or severe heart failure, orthopedic limitations preventing exercise, active depression requiring medication change, uncontrolled sleep disorders including severe sleep apnea or narcolepsy, dementia precluding safe participation, and uncontrolled medical conditions such as diabetes or hypertension.

Trial Location

The University of Aarhus in Denmark is a leading European center for movement disorders research, with expertise in Parkinson's disease rehabilitation, exercise physiology, neuroimaging of movement disorders, and clinical trial methodology.

Future Directions

This trial contributes to the growing evidence base for exercise as medicine in PD. Results may inform guidelines for exercise prescription in PD fatigue, healthcare coverage for exercise programs, development of tailored exercise interventions, and biomarkers predicting exercise response.

References

See Also

• [AMPK Agonist Therapy for Neurodegeneration](/wiki/ideas-payload-ampk-agonist-neurodegeneration) — activates
• [BrainSpan Atlas](/wiki/datasets-brainspan-atlas) — protects_against
• [Brain-Derived Neurotrophic Factor (BDNF)](/wiki/proteins-bdnf) — activates
• [BMAL1 (ARNTL) Gene](/wiki/genes-bmal1) — regulates
• [NRF2 — Nuclear Factor Erythroid 2-Related Factor 2](/wiki/proteins-nrf2) — modulates
• [PPARGC1A Gene](/wiki/genes-ppargc1a) — activates
• [ULK1 Protein](/wiki/proteins-ulk1) — activates