Stroke Recovery

A stroke happens when blood flow to part of the brain is cut off or reduced, depriving brain cells of oxygen and nutrients. Most strokes, about 85%, are ischemic, caused by a blood clot or narrowed artery blocking blood flow. The rest are hemorrhagic, caused by a blood vessel in the brain bursting. Major risk factors include high blood pressure, atrial fibrillation, diabetes, high cholesterol, smoking, obesity and older age. Symptoms come on suddenly. Heart & Stroke Canada’s FAST test helps people recognize them: Face drooping, Arm weakness, Speech difficulty, Time to call 9-1-1. Other signs can include sudden numbness, vision loss, confusion, dizziness or a severe headache. Survivors often live with lasting effects, such as weakness on one side of the body, speech and memory problems, fatigue and depression, which is why researchers are looking for ways to support recovery months or years after a stroke.

Potential mechanisms of HBOT in Stroke:

Researchers have several theories about how hyperbaric oxygen might help some people in the chronic stage of stroke. After a stroke, some brain tissue near the damaged area may stay alive but not work properly, because it gets too little blood and oxygen to function normally. Scientists sometimes call these “idling” brain cells. In the 2013 Israeli trial, brain scans after treatment showed improved blood flow mainly in areas like this, where tissue was still alive but underactive. Hyperbaric oxygen raises the oxygen dissolved in the blood, which researchers think may give these cells the energy they need to start working again. Laboratory and small human studies suggest it may also encourage new blood vessel growth, support the brain’s natural ability to rewire itself (called neuroplasticity), increase growth factors that help brain cells survive and connect, and reduce inflammation. Some researchers propose that repeated sessions, where oxygen levels rise and then fall, may switch on the body’s natural repair signals.

Studies are focused on the chronic stage of strokes, months or years later after the initial event to help with the lasting effects.

Dr. Efrati is a world-renowned hyperbaric oxygen researcher. A review and the links to his studies are listed below.

This Israeli trial enrolled 74 patients who had had a stroke 6 to 36 months earlier; 59 completed it. One group received 40 HBOT sessions (100% oxygen at 2 atmospheres, 90 minutes, five days a week). The other group waited two months without treatment, then received the same course. Stroke severity scores, daily living ability and quality of life improved after HBOT in both groups but didn’t change during the waiting period. Brain scans showed improved blood flow in areas with damaged but still living tissue. The authors called it a “proof of concept.”

Read the study (PubMed Central)

Researchers looked back at the records of 162 people treated an average of nearly three years after their stroke. Memory, attention and thinking speed scores improved after 40 to 60 sessions.

Read the study (SAGE Journals)

A man eight years post-stroke regained walking ability and showed cognitive gains after 60 sessions plus rehabilitation.

Read the article (NeuroNews International)

Another group of researchers reviewed the records of 91 people who had a stroke between 3 months and 15 years earlier. After 40 to 60 hyperbaric oxygen sessions, all memory measures improved, and brain scans showed increased activity in the areas linked to memory.

Read the study (APA PsycNet)

Researchers followed seven people, all at least a year past an ischemic stroke. Each served as their own comparison: after three months of baseline testing, they received 40 hyperbaric oxygen sessions in two 4-week blocks. Six completed the study. Memory and walking speed (about 20% faster) improved, and these gains held three months later. Arm movement, sleep and overall recovery scores also improved, while language, balance and mood didn’t change significantly. One person withdrew because of ear pain. The authors called the results preliminary because the study was very small and had no control group or blinding.

Read the study (PubMed)

Health Canada Compliance Notice

Health Canada regulates the approved use of HBOT for 13 specific medical conditions. While HBOT is recognized for the 14 conditions outlined by the Undersea & Hyperbaric Medical Society, any additional uses must be assessed through a comprehensive consultation with our qualified naturopathic doctors. Patients are encouraged to discuss their health concerns and explore whether HBOT is appropriate for their care.