This article is part of the HBOT Radar series, where we summarize the latest published hyperbaric oxygen therapy research.
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Disclaimer: This article is intended for educational and informational purposes only. It summarizes published medical research conducted in clinical settings and does not evaluate Brain Spa Hyperbaric products. The hyperbaric chambers offered on this website are non-medical wellness devices and are not intended to diagnose, treat, cure, or prevent any disease. Do not make medical decisions based on this article — consult a qualified healthcare professional.
📌 40 Sessions of Oxygen. 30 ME/CFS Patients. And the First Brain Scans Showing Something Changed.
🔍 What this study explored
There's a disease that affects millions of people worldwide, has no approved treatment, no reliable diagnostic test, and until recently was dismissed by much of the medical establishment as psychological. It's called ME/CFS — myalgic encephalomyelitis/chronic fatigue syndrome — and if you haven't lived through it or watched someone close to you suffer from it, the name barely scratches the surface.
ME/CFS isn't "being tired." It's a debilitating condition where the body's energy system appears fundamentally broken. Profound, crushing fatigue that doesn't improve with rest. Cognitive impairment so severe patients call it "brain fog" — though "brain shutdown" might be more accurate. And the hallmark symptom: post-exertional malaise (PEM), where even minor physical or mental effort can trigger a catastrophic crash lasting days or weeks.
Since COVID-19, ME/CFS has exploded in visibility. An estimated 90% of participants in this study developed ME/CFS after a COVID infection. But the disease has been around for decades, and the lack of effective treatment remains one of the most glaring gaps in modern medicine.
This is why a team at Charité — Universitätsmedizin Berlin, one of Europe's oldest and most respected hospitals, decided to test whether HBOT could help. And they didn't just measure symptoms. They scanned the patients' brains.
🌬️ HBOT protocol used in this study
- Patients: 30 ME/CFS patients (mean age 42, 23 women, 7 men). Diagnosed using the Canadian Consensus Criteria. 90% post-COVID triggered.
- Protocol: 40 HBOT sessions (specific ATA and duration not detailed in available extracts, but consistent with standard clinical HBOT protocols used in the Charité's hyperbaric medicine center)
- Assessments: Baseline, during treatment, and 4 weeks after completion
- Primary outcome: Change in Physical Functioning subscale of SF-36 (a standard quality-of-life questionnaire)
- Secondary outcomes: Fatigue severity, pain, cognitive performance, handgrip strength, exercise capacity
- Brain imaging: Functional MRI (fMRI) — before and after treatment — measuring connectivity patterns between brain regions
- Comparison: Brain scans were also compared against healthy controls to identify what's different in ME/CFS brains
Important note: This is a preprint — it has been posted on medRxiv but has NOT yet undergone peer review. This is an important caveat throughout.
This study was conducted in a clinical hospital setting under medical supervision. Results from clinical research cannot be directly applied to other settings or devices — always consult a healthcare professional.
📊 Key findings
The symptoms improved — but the main endpoint technically missed
Let's be straightforward about this, because honesty matters more than hype.
The primary outcome — the SF-36 Physical Functioning score — improved by an average of 6.3 points. That's a real improvement. But the researchers themselves defined a "clinically meaningful" improvement as 10 points or more. So the average patient improved, but not enough to cross the bar the researchers set for themselves.
However, looking deeper into the data reveals a more nuanced picture. Fatigue decreased significantly (Hedges' g = −0.87 — a large effect size). Pain improved. Cognitive performance improved. Handgrip strength improved. These aren't trivial outcomes for patients who previously had essentially no treatment options.
And importantly: 7 out of 37 enrolled patients dropped out before completing all 40 sessions. The published analysis includes only the 30 completers. If the dropouts had worse outcomes, the real-world effect might be smaller still.
The brain scans told a different story — and it's the most interesting part
Here's where this study goes from "modest clinical improvement" to "genuinely important science."
Before treatment, the ME/CFS patients' brains looked different from healthy controls on fMRI. Specifically, their thalamus — the brain's central relay station that routes sensory information to the cortex — showed abnormally increased connectivity with motor, sensory, and visual brain regions. The thalamus was, in a sense, "hyperconnected" — firing off too many signals to too many places.
This is consistent with an emerging theory that ME/CFS involves a kind of neurological "noise" — the brain's filtering system is overwhelmed, which could explain the sensory sensitivity, cognitive fog, and exhaustion that patients experience.
After 40 HBOT sessions, this thalamic hyperconnectivity normalized. The abnormal connections that distinguished ME/CFS patients from healthy controls were no longer significant. The brain scans of treated patients looked more like healthy brains.
And the clincher: patients whose thalamic connectivity normalized the most were the same patients who improved the most clinically (p < 0.001). The brain changes and the symptom changes tracked together.
This is the first neuroimaging evidence showing HBOT-induced brain changes in ME/CFS. It doesn't prove HBOT fixes the disease — but it shows that something measurable is happening in the brain, and it correlates with how patients feel.
🧠 What this study tells us — and what it doesn't
Why it matters:
This is the first time anyone has shown objective brain changes following HBOT in ME/CFS patients using functional MRI. For a disease that has been dismissed as "all in the head" (and simultaneously had zero evidence of what's happening in the head), having visible, measurable brain data is significant — both scientifically and for the millions of patients fighting for recognition.
The Charité team is not a fringe group. This is Germany's largest university hospital, funded by the German Federal Ministry of Education and Research. The principal investigators (Scheibenbogen, Finke) are established ME/CFS researchers. The study was part of the National Clinical Studies Group (NKSG) — a government-funded platform for developing ME/CFS therapies.
Where to pump the brakes:
- This is a preprint. Not peer-reviewed. The methods, statistics, and conclusions have not been independently vetted. Until peer review and publication in a journal, these results should be treated as preliminary.
- No control group. Every patient received HBOT. Without a sham group, we can't know how much of the improvement was due to HBOT versus placebo effect, natural fluctuation, or the simple benefit of regular medical attention over 8 weeks.
- The primary endpoint missed. The average 6.3-point SF-36 improvement fell below the 10-point threshold the researchers defined as clinically meaningful. This is an inconvenient fact that shouldn't be glossed over.
- 7 dropouts excluded. If those patients dropped out because they weren't improving or were getting worse, the results could be inflated.
- Small sample. 30 patients is enough to detect trends but not enough to be definitive.
- The Science for ME patient community raised valid concerns. Online discussion among ME/CFS patients and researchers noted that 40 sessions is a substantial commitment for patients with severe exercise intolerance — and if 40 sessions still don't achieve clinically meaningful improvement on the primary outcome, the cost-benefit calculation is questionable.
The honest summary: The brain imaging data is genuinely exciting and novel. The clinical improvement is real but modest and falls short of the study's own success threshold. This is a signal worth following, not a treatment to recommend.
📌 Takeaway for the community
- 30 ME/CFS patients (90% post-COVID) received 40 HBOT sessions at Charité Berlin — symptoms improved modestly but the primary outcome fell below the predefined threshold for clinical meaningfulness
- Fatigue, pain, cognition, and grip strength all showed statistically significant improvement — meaningful gains for patients with no approved treatment
- Functional brain imaging revealed that ME/CFS patients had abnormally hyperconnected thalamus regions compared to healthy controls — and this hyperconnectivity normalized after HBOT
- Patients whose brain connectivity improved the most also showed the greatest clinical improvement — the first neuroimaging correlation for HBOT in ME/CFS
- Critical caveats: this is a preprint (not peer-reviewed), has no control group, the primary endpoint technically missed, and 7 of 37 enrolled patients dropped out
- A controlled trial is now needed to confirm whether these effects are truly due to HBOT — and the Charité team is already enrolling for a follow-up study with 60 participants
- This study was conducted in a clinical hospital setting under medical supervision — results cannot be directly applied to other settings or devices
Source: https://www.medrxiv.org/content/10.1101/2025.10.29.25339096v1
Kim L, Cammà G, Kedor Peters C, Mantwill M, Müller O, Leprêtre N, Heindrich C, Rust R, Krill M, Hartung TJ, Reeß LG, Krohn S, von Heymann C, Wittke K, Finke C, Scheibenbogen C. Hyperbaric oxygen therapy improves clinical symptoms and functional capacity and restores thalamic connectivity in ME/CFS. medRxiv preprint. 2025 Oct 31. doi: 10.1101/2025.10.29.25339096.
Educational disclaimer
This content summarizes findings from published medical research for educational purposes only.
The hyperbaric chambers sold on this website are non-medical wellness devices and are not intended to diagnose, treat, cure, or prevent any disease.
The studies discussed here were conducted in clinical medical settings using medical-grade interventions. The inclusion of research summaries does not imply that similar outcomes can be achieved using non-medical wellness devices.
