Hydrogen Gas Inhalation Treatment in Acute Cerebral Infarction: A Randomized Controlled Clinical Study on Safety and Neuroprotection
Ono H et al. · J Stroke Cerebrovasc Dis. 2017;26(11):2587–2594.
Study at a glance
Human
Acute ischemic stroke with NIHSS 2–6, treatment within 6–24 hours and selected small-to-medium MRI lesions; major-artery occlusion and thrombolysis recipients were excluded.
3% H₂ through a non-rebreathing face mask for 1 hour twice daily for 7 days, with ozagrel. Edaravone was avoided in the H₂ group. · Reported H₂ concentration 3%; balance gas and inspired O₂ composition were not specified in the checked article. No component flow is calculated from concentration alone.
1 hour twice daily for 7 days; outcomes assessed over 2 weeks.
NIHSS, MRI signal and Barthel Index findings favored H₂. Brunnstrom, mRS and FIM differences were not significant; most vital signs and blood tests were also null. No significant adverse effects were reported. This small, short study does not establish long-term functional benefit, mortality benefit or general safety.
Small single-center trial, short follow-up, incomplete masking, unequal background medication and missing rehabilitation data. Not evidence for unsupervised use, severe stroke, other exposures or modern thrombectomy combinations. Hydrogen Heath Medical Laboratory Co., Ltd. funded the study; sponsors reportedly had no study/report role. S. Ohta disclosed a medical-H₂ patent and no patient-registration/data-collection/interpretation role; other authors declared no conflicts.
What kind of evidence is this?
Human
Randomized parallel-group clinical study; no sham machine and not fully blinded. Outcome collection and analysis were reported masked; allocation concealment was not established.
Other neurological conditions
Inhaled H₂
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Acute ischemic stroke with NIHSS 2–6, treatment within 6–24 hours and selected small-to-medium MRI lesions; major-artery occlusion and thrombolysis recipients were excluded.
50 enrolled and randomized, 25 per group. Nine patients (3 H₂, 6 control) were excluded from the final physical-therapy assessment; endpoint denominators should not be assumed identical.
1 hour twice daily for 7 days; outcomes assessed over 2 weeks.
3% H₂ through a non-rebreathing face mask for 1 hour twice daily for 7 days, with ozagrel. Edaravone was avoided in the H₂ group.
Inhaled H₂-containing gas; not identified as Brown’s gas. Gas concentration was checked by chromatography.
Reported H₂ concentration 3%; balance gas and inspired O₂ composition were not specified in the checked article. No component flow is calculated from concentration alone.
Total gas flow and absolute H₂ flow were not reported in the checked main article.
O₂ concentration and flow in the administered mixture were not reported; pulse oximetry is not a delivered-gas specification.
No H₂ or sham. All controls received edaravone; 76% also received ozagrel and 24% argatroban. Both groups received physical therapy; background medication was not identical.
Outcomes and reported result
NIHSS, MRI relative signal intensity, vital signs, blood tests and rehabilitation scales (Barthel, Brunnstrom, mRS, FIM); no single primary endpoint clearly designated in the checked article.
NIHSS, MRI signal and Barthel Index findings favored H₂. Brunnstrom, mRS and FIM differences were not significant; most vital signs and blood tests were also null. No significant adverse effects were reported. This small, short study does not establish long-term functional benefit, mortality benefit or general safety.
Main full-text methods, results, figures/captions, limitations and declarations compared with the record. Published numerical effect sizes were not reconstructed from graphs; registry history and any supplementary material were not fully checked.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Small single-center trial, short follow-up, incomplete masking, unequal background medication and missing rehabilitation data. Not evidence for unsupervised use, severe stroke, other exposures or modern thrombectomy combinations. Hydrogen Heath Medical Laboratory Co., Ltd. funded the study; sponsors reportedly had no study/report role. S. Ohta disclosed a medical-H₂ patent and no patient-registration/data-collection/interpretation role; other authors declared no conflicts.
Selected mild acute ischemic stroke in a monitored research protocol; no treatment, concentration or device recommendation.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 28669654 · DOI: 10.1016/j.jstrokecerebrovasdis.2017.06.012
PubMed identifies a free article; direct publisher HTML/PDF retrieval was unavailable during this check. A licensed public full-text copy, marked Article in Press, was read on ResearchGate.
Hydrogenology editorial · AI-assisted main full-text comparison, licensed public Article-in-Press copy · 29 October 2026. Publisher PDF, registry history and independent clinical review not completed.
Materials and Methods; Results; Table 1; Figs 1–6 captions; Study Limitations; Discussion; first-page funding/patent disclosures.
AI-assisted comparison with the licensed public main article copy on ResearchGate, checked against PubMed identity and publisher disclosures on 29 October 2026. Sections: Materials and Methods; Results; Table 1 and Figs 1–6 captions; Study Limitations; Discussion; first-page disclosures. No independent clinician review.
29 October 2026
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