Investigating Central Contributions to Fatigue Using Non-invasive Brain Stimulation

Phase 2Not Yet RecruitingNCT07613970

Vrije Universiteit Brussel120 enrolled

Overview

The goal of this interventional study is to understand the contribution of the central components to the manifestation of neuromuscular fatigue in stroke survivors. The study will include adults with a first-ever stroke in the subacute phase. The main question it aims to answer: • How does the brain activity contribute to the manifestation of neuromuscular fatigue in stroke survivors? Researchers will compare stroke participants receiving active vs sham tACS in a single session before the fatiguing contractions to determine whether central changes can influence fatigue onset/progression. Participants will: * Perform repeated leg muscle contractions until fatigue while seated in an experimental setup * Receive either active or sham tACS for 20 minutes before the fatiguing contractions. * Wear non-invasive sensors to record brain activity (EEG) and muscle activity (EMG) during the task * Complete the study during a single experimental session in which fatigue-related changes will be measured throughout the task

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Enrollment

120

Conditions

Stroke Cerebrovascular Accident (CVA)Ischemia Stroke

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: First-ever stroke ≥18 years Subacute phase: 1 week to 6 months post-stroke Quadriceps (hemiplegic side) strength ≤3/5 (Medical Research Council (MRC)) Montreal Cognitive Assessment (MoCA) ≥21 Exclusion Criteria: History of a previous stroke Severe spasticity (Modified Ashworth Scale (MAS) 3-4 in quadriceps/hamstrings) Other neurological, motor, musculoskeletal, or orthopedic conditions affecting trunk stability and lower limb mobility Non-cerebral strokes (e.g., brainstem, cerebellar), or dementia (MoCA ≤20) Current or former athletes. Athletes are defined as individuals who participated in organized competitive sports and engaged in structured training ≥3 sessions per week for ≥1 year within the 5 years preceding stroke Contraindications for tACS (e.g., presence of a deep brain stimulator, pacemaker, head wound, etc.).

Outcomes

Primary Outcomes

Absolute and relative spectral power and ERD/ERS magnitude

Fatigue-related changes in sensorimotor cortical activity will be assessed using EEG-derived absolute and relative spectral power in the mu (8-12 Hz), beta (13-30/35 Hz), and gamma (30/35-100 Hz) frequency bands, as well as changes in event-related desynchronization/event-related synchronization (ERD/ERS) magnitude over time. Measurements will be obtained at pre-fatigue baseline and continuously during the fatiguing task, with data segmented into contraction epochs and grouped into four fatigue phases for analysis.

Time frame: Outcome measure will be recorded at baseline and throughout the fatiguing contractions in the single experimental session (up to 40 minutes) and compared over 4 fatigue phases.

EMG median frequency

Peripheral manifestations of fatigue will be assessed using shifts in EMG median frequency during repeated contractions. Data will be recorded continuously during the task and analyzed across contraction epochs grouped into four fatigue phases.

Time frame: Outcome measure will be recorded throughout the fatiguing contractions in the single experimental session (up to 40 minutes) and compared over 4 fatigue phases.

Time-to-task failure (TTF)

The duration a participant can sustain the prescribed fatiguing exercise until exhaustion

Time frame: Outcome measure will be recorded throughout the fatiguing contractions until exhaustion

Secondary Outcomes

Corticomuscular coherence

The interaction between cortical and muscular activity will be assessed using CMC, which quantifies synchronization between EEG and EMG signals. Corticomuscular coherence will be assessed from simultaneous EEG and EMG recordings during repeated contractions and analyzed across contraction epochs grouped into four fatigue phases.