Effects of Exercise and Sleep on Motor Learning and Functional Abilities in Multiple Sclerosis

Effects of Aerobic Exercise and Daytime Sleep on Neurorehabilitation and Functional Abilities in Multiple Sclerosis: Evidence of Training the Brain in Neurorehabilitation

The ExSiMS study is a randomized, controlled crossover study including 20 individuals (18-70 years) diagnosed with relapsing remitting Multiple Sclerosis (MS) This project investigates, through behavioral and neurophysiological measurements, how aerobic exercise on an ergometer bike and sleep in the form of a nap and overnight sleep may enhance cortical motor skill learning evaluated by a complex hand motor skill test and thereby improve functional capacity in individuals with MS. Beyond the effect on motor skill learning, the project investigate the effect on electroencephalography (EEG) - electromyography (EMG) coherence.

The study hypothesizes that individuals with neurological conditions, such as multiple sclerosis (MS), may experience beneficial effects on specific motor rehabilitation through systematically planned cardiovascular exercise and sleep scheduling, due to positive impacts on memory consolidation.

Aims:

• Investigate the brain's neurophysiological responses and memory effects following a training intervention and, separately, sleep, in the form of a power nap, in individuals with MS.
• Examine whether these effects persist beyond the few days previously observed in healthy individuals by implementing a longer-term intervention.
• Explore whether the training effect is influenced by disease activity in the brain, such as during relapses and during immunosuppressive treatment.
• Assess whether the presence of abnormally reduced cognitive endurance (fatigue) affects the impact of the intervention involving exercise and sleep.

The study is based on documented positive effects of physical activity and sleep in both young and older adults, as well as in individuals recovering from stroke. The research thus offers promising perspectives for broader applications within neurorehabilitation, and particularly for MS, as the disease is associated with functional impairments. At the same time, both physical exercise and sleep represent meaningful interventions that should be thoughtfully integrated into rehabilitation strategies.

The ExSiMS-project consists of both a proof-of-concept study and a longitudinal study.

In both studies, participants will perform a visuomotor accuracy tracking task (VATT) with their dominant hand on the main experimental days. The participants will wear EEG and EMG electrodes during the VATT. This will make it possible to investigate cortical activity during skill acquisition and later analyse the corticomuscular coherence. After the VATT, the participants will be randomized to either 20 min aerobic exercise on an ergometer bike, a short 30-minute nap or control (sitting rest). The interventions will run over a longer period of time in the longitudinal study.

The participants will be asked to do a retention test of the visuomotor accuracy tracking task 24 hours later.

The studies will run over more experiment days divided into two experiment blocks of at least two experiment days separated by between two weeks to three months.

Methods:

• Electroencephalography (EEG) and Electromyography (EMG)
• Actigraphy/Accelerometry
• Visuomotor Accuracy Tracking Task (VATT)
• Training on an Ergometerbike: Graded Exercise Test (GXT), High Intensity Interval Training (HIIT)
• Polysomnography (PSG)

Inclusion Criteria:

• Competent individuals (aged 18-70) diagnosed with early relapsing-remitting MS
• Expanded Disability Status Score, 1 < EDSS < 4.5
• MRC muscle strength ≥ 4+ in the dominant hand

Exclusion Criteria:

• Implanted devices, such as pacemakers or stimulators
• Epilepsy or neuromuscular diseases