Stroke is the second leading cause of death worldwide and the third leading cause of disability. In stroke, the damaged area of the brain is associated with a corresponding loss of function. This can manifest as visual disturbances, difficulty moving, sensory impairment or cognitive problems. Most stroke research focuses primarily on motor functions, but an estimated nearly half of stroke survivors suffer from cognitive impairments of varying severity.
Is post-stroke recovery possible even years later?
For a long time, it was believed that recovery from brain injury occurs mainly in the first months after a stroke. However, research over recent decades suggests that even in the chronic phase, the brain may retain a degree of plasticity — the ability to form new functional connections persists.
One method that has been studied in the context of recovery is hyperbaric oxygen therapy (HBOT). This is a procedure in which 100% oxygen is breathed in a specialised chamber at a higher air pressure than normal.
One method that has been studied in the context of recovery is hyperbaric oxygen therapy (HBOT). This is a procedure in which 100% oxygen is breathed in a specialised chamber at a higher air pressure than normal.
Kuidas hapnik ajju jõuab?
Under normal conditions, oxygen is transported mainly by haemoglobin in red blood cells. Under hyperbaric conditions, however, the amount of oxygen dissolved in blood plasma increases significantly. The elevated pressure allows oxygen to diffuse into tissues at a higher concentration than at normal pressure.
This means that even areas where blood supply has been reduced may receive better oxygenation. Such repeated stimulation can trigger mechanisms associated with the formation of new blood vessels, reduction of inflammation and swelling, and neuroplasticity.
Mida näitavad teadusuuringud insuldijärgse baroteraapia ehk HBOT-i kohta?
The connection between post-stroke recovery and hyperbaric oxygen therapy is attracting increasing interest from researchers. However, the volume of studies conducted in the field is still relatively small. The existing scientific literature concludes that in some individuals, hyperbaric oxygen therapy may support post-stroke recovery even years later.
A study published by Efrati et al. included patients with chronic stroke whose stroke had occurred at least 6–36 months before the first hyperbaric therapy session. According to traditional understanding, the intensive recovery period is considered to be mainly the first six months. Participants received 40 hyperbaric therapy sessions (100% oxygen, 2 ATA, 5 times per week). Results were assessed using both neurological scales and brain imaging.
Participants received 40 hyperbaric therapy sessions (100% oxygen, 2 ATA, 5 times per week). Results were assessed using both neurological scales and brain imaging.
The study showed statistically and clinically significant improvements in neurological functions, daily activities and quality of life. Notably, brain imaging revealed increased metabolic activity in areas that had previously been functionally suppressed. The authors therefore concluded that HBOT may trigger neuroplasticity mechanisms even years after a stroke.
Boussi-Gross et alstudied improvements in cognitive functions. The study included patients whose stroke had occurred at least several months earlier and whose condition was assessed before and after 40–60 hyperbaric therapy sessions.
In terms of post-stroke recovery, the important results showed statistically significant improvements in memory, attention and information processing speed. Memory function improved most clearly. The study was significant precisely because most post-stroke interventions focus on motor recovery, whereas cognitive deficits often affect the quality of daily life just as strongly — or even more so.
Also study published by Efrati et al. included patients with chronic stroke whose stroke had occurred at least 6–36 months before the first hyperbaric therapy session. According to traditional understanding, the intensive recovery period is considered to be mainly the first six months. Hadanny et al also analysed patients whose stroke had occurred at least three months earlier and who completed 40–60 hyperbaric therapy sessions. Improvements in cognitive capacity were examined using computer-based tests.
Results showed that 86% of patients achieved clinically significant improvement in at least one cognitive domain. The best results were observed in memory and higher cognitive functions, including information processing speed.
In summary, various researchers have studied the effects of hyperbaric oxygen therapy on both cognitive and motor functions in the chronic post-stroke phase. The main findings suggest that in some patients, a course of hyperbaric therapy may be associated with improvements in memory, attention and information processing, as well as in mobility and daily functioning. While not all patients respond in the same way and research is ongoing, the existing evidence suggests that brain plasticity may persist for years after a stroke — and that in certain cases, hyperbaric oxygen therapy may support both cognitive and functional recovery.
Allikad
Viide:
Boussi-Gross R et al. Improvement of memory impairments in poststroke patients by hyperbaric oxygen therapy. Neuropsychology, 2015.
(Kättesaadav: https://pubmed.ncbi.nlm.nih.gov/26612564/)
Viide:
Efrati S et al. Hyperbaric oxygen induces late neuroplasticity in post stroke patients. PLoS ONE, 2013.
(Kättesaadav: https://pubmed.ncbi.nlm.nih.gov/23335971/)
Viide:
Hadanny A et al. Hyperbaric oxygen therapy improves neurocognitive functions in chronic post-stroke patients. Restorative Neurology and Neuroscience, 2020. (Kättesaadav: https://pubmed.ncbi.nlm.nih.gov/31985478/)
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