Hyperbaric Oxygen Therapy for Chronic Fatigue Syndrome (CFS)

Physical performance evaluated by cardiopulmonary exercise test (CPET) on a bicycle or a treadmill. CPET will be used to determine the peak oxygen consumption (Peak VO2), first ventilatory threshold (VT1) and if possible, the second ventilatory threshold (VT2).

A self-report instrument assessing the frequency and severity of post-exertional malaise symptoms in individuals with ME/CFS.

Total scores typically range from the minimum value (no symptoms) to the maximum value (most severe and frequent symptoms), with higher scores indicating worse post-exertional malaise.

A self-reported measure of health-related quality of life across eight domains. Each SF-36 scale is transformed to a 0 to 100 score, where 0 represents the worst health status and 100 represents the best health status.

Higher scores indicate better health-related quality of life.

a self-report questionnaire that assesses sleep quality and disturbances over the previous month.

The measure consists of 19 individual items, creating 7 components that produce one global score.

The score ranges from 0 to 21, with higher scores indicating poorer sleep quality.

The BSI-18 will be used to evaluate psychological distress. An 18 item self-report questionnaire which generates a global stress index (GSI), and three subscales: depression, anxiety, and somatization.

Each item is rated on a 5-point scale, with distress ratings ranging from 0 (not at all) to 4 (extremely).

Higher scores indicate greater psychological distress.

A brief cognitive screening tool with high sensitivity and specificity for detecting mild cognitive impairment (MCI).

The MoCA total score ranges from 0 to 30, with higher scores indicating better cognitive performance.

A score of 26 or above is considered normal and a score lower than 26 is the cutoff point for diagnosis of cognitive impairment.

NeuroTrax (NeuroTrax Corp., Houston, TX) is a computerized neurocognitive battery of tests used to assess brain wellness across multiple cognitive domains, including memory, executive function, visual spatial perception, verbal function, attention, information processing speed, and motor skills

Images will be acquired on MAGNETOM Vida 3T Scanner, T1-weighted images will be used for gray matter and hippocampal volumetric measurement.

Statistical parametric mapping software SPM12, will be used for brain segmentation.

Voxel-based morphometry (VBM) procedure to calculate the whole-brain volumes.

Resting-state and task-related brain EEG measures.

EEG will be recorded using a high-density dry-electrode system (115 channels, EEG-Sense, Israel).

Recordings will include eyes-open rest (3 minutes), eyes-closed rest (3 minutes), and 20 minutes of cognitive tasks (N-Back, Stroop, Flanker, and multiple-object tracking).

EEG data will undergo standard preprocessing (filtering, line-noise and artifact removal, and down-sampling).

Primary EEG outcomes will include spectral measures (peak frequency and relative power; alpha, beta, theta, and delta band power), power spectral distribution, and functional connectivity indices.

Event-related potentials will be extracted for the cognitive tasks, including event-related synchronization and desynchronization (ERS/ERD), with averages computed across artifact-free trials.

Physiological sleep EEG signals will be collected using a home wearable EEG headband (Muse S) paired with a mobile application.

Multi-channel EEG will be recorded from frontal and temporal locations, together with inertial sensors to capture movement and head position.

Primary sleep EEG outcomes will include validated sleep-wake classification and sleep staging metrics (percent time in light, deep, and REM sleep), sleep timing (bedtime, sleep onset, awakenings, final wake time), and sleep continuity indices (wake after sleep onset and sleep efficiency).

Secondary analyses will include signal-level EEG features such as spectral power in conventional frequency bands and spindle-like activity.

Higher sleep efficiency and higher proportions of deep (slow-wave) sleep will be interpreted as better sleep quality.

The 10-min NASA Lean Test (NLT) will be performed by asking the subject to lay supine for 10 min and then leaning against a wall for 10 min, while blood pressure and heart rate are measured

Body composition will be assessed using the seca mBCA Ultra, a clinically validated segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) system.

The device estimates fat mass, fat-free mass, skeletal muscle mass, and total body water based on multi-frequency impedance measurements across body segments.

Outcomes will include absolute values (kg or liters) and relative values (percentage of body weight) for each compartment. Higher fat mass and body fat percentage indicate greater adiposity, whereas higher fat-free mass and skeletal muscle mass indicate greater lean tissue.

Quick, non invasive assessment of the maximal force generated when squeezing a hand dynamometer. Reflecting strength of the hand and forearm muscles and serving as a proxy for overall muscle weakness, fatigability, and disease severity

Whole blood and plasma will be collected and stored for future biomarker analysis

A voluntary test. Participants will undergo a muscle biopsy using a 0.3mm Trucut needle in an aseptic technique. Muscle sample will be analysed using the Oxygraph (Oroboros Inc, Austria) for oxygen respiratory function, as well as staining for mitochondrial proteins and Mitochondrial DNA.