Exploring the Effects of Exercise on Memory and Cognition in Parkinson´s Disease

The study aims to assess the effects of cardiovascular (aerobic) training on memory formation and cognitive function in people with Parkinson's disease. Participants will be randomly allocated to one of two groups either performing cardiovascular training (experimental group) or stretching (control group) for twelve weeks, three times a week. The primary aim is to examine whether moderate-intense cardiovascular training (MICT) improves procedural memory formation (primary outcome) compared to stretching. Secondary outcomes include episodic memory formation, cognitive function, cardiorespiratory fitness, sleep quality, and brain-derived neurotrophic factor (BDNF) blood concentration levels.

Besides the disabling cardinal motor symptoms, non-motor symptoms are a common clinical feature of Parkinson's disease (PD). These non-motor symptoms include, amongst others, cognitive decline and memory deficits. A growing body of evidence suggests that cardiovascular training has the potential to induce functional and structural brain changes that can translate into improved cognitive function, including memory. While data is mainly derived from studying rodents and healthy populations, cardiovascular exercise might also counteract cognitive decline and memory deficits in people with Parkinson's disease (pwPD). Therefore, the primary aim of the study is to investigate the effects of a twelve-week cardiovascular training on memory formation in pwPD.

In a randomized controlled trial, 60 persons with mild to moderate PD (i.e., Hoehn \& Yahr ≤3) will either perform moderate-intensity cardiovascular training (experimental group) or stretching (control group) for twelve weeks (three times per week, totaling 36 training sessions; duration per training session 30 to 55 min). Participants will perform a procedural memory task before and after the intervention to analyze the effects on non-declarative memory formation (primary outcome). In addition, secondary and exploratory analyses will include the assessment of episodic memory formation, cognitive function, cardiorespiratory fitness, sleep quality, and BDNF blood concentration levels. The findings of the present study contribute to the current discussion on the neuroplastic effects of cardiovascular training and may have important implications for neurorehabilitation in pwPD.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosed Parkinson's disease
* Disease stage ≤3 on the Hoehn \& Yahr scale
* Age ranging from 50 - 80 years
* Naive to the memory tasks (primary outcomes)
* Ability to stand and walk at least 10 meters independently

Exclusion Criteria:

* Atypical Parkinsonism
* Significant level of cognitive impairment (i.e., Montreal Cognitive Assessment \<21)
* Deep brain stimulation or brain pacemaker
* Diagnosed psychiatric illness
* Known clinically relevant neurological, internal or orthopedic conditions besides Parkinsonism that would interfere with the exercise paradigm
* Exceeding the recommended level of cardiovascular exercise for older adults (i.e., cardiovascular exercise done ≥150 min per week of moderate-intensity or ≥75 min per week of vigorous-intensity)