Hyperbaric Oxygen Therapy Improves Neurocognitive Functions: Randomized Controlled Trial

Each year, about 795,000 Americans suffer from a stroke, and roughly 185,000 of that population recognize the symptoms from previous attacks. Since strokes carry the third highest rate for disabilities among patients, it’s not uncommon for survivors to undergo brain injuries, contributing to a loss of function.

Most strokes contribute primarily to motor dysfunction, leading most treatment options to revolve around speech, physical, and occupational therapy to repair stability, strength, and mobility. However, 50% of post-stroke patients also endure severe cognitive ailments alongside sensory and vision concerns, inspiring us to test the effects of hyperbaric oxygen therapy for neurological conditions.

At NexGen Hyperbaric, our team of scholarly physicians is constantly researching ischemic and hemorrhagic strokes to bring patients closer to a symptom-free existence. Below are our current findings on neurocognitive functions and HBOT studies and what we do to assist post-stroke patients in Edwards, CO.

What Are Neurocognitive Functions?

Neurocognitive functions are cognitive functions that tie to cortical networks and neural pathways in the brain. Impairments within these networks or pathways contribute to lower performances in functions or a lack thereof.

Ischemic strokes, originating from a limited or temporary absence of blood flow to a particular part of the brain, are responsible for 68% of all stroke cases. Still, they don’t cause as much neurocognitive damage as hemorrhagic strokes. Hemorrhagic strokes comprise 32% of stroke cases and develop from one or more ruptured blood vessels, exposing the brain to internal bleeding.

Not only are hemorrhagic strokes more closely tied to cognitive dysfunction, but they tend to attack multiple cognitive domains simultaneously, including the four main domains: executive function, memory, language, and visual-spatial. These deficits also have a high chance of occurring with severity among seniors and patients with a stroke history or prior injury to their global cognitive functions.

A Study on the Effects of HBOT on Neurocognitive Functions

While domain-specific cognitive rehabilitation exists, aiding many post-stroke patients in recovery one to three months after injuries, their restricted success rates don’t guarantee results in most cases. Luckily, hyperbaric oxygen therapy for neurological conditions has shown promising signs of enhancing the memory domain in multiple clinical studies.

Since the body uses oxygen to heal, exposing the brain to 100% oxygen with enhanced pressure allows for more oxygen intake and faster healing during HBOT. When using hyperbaric oxygen therapy for brain injury, patients receive high oxygen concentration levels in the bloodstream and affected tissues. This process increases energy levels for brain tissue regeneration.

It encourages neuroplasticity, allowing the brain to reorganize or rewire itself and grow new neurons after sustaining injuries. HBOT also stimulates axonal growth, cell proliferation, neural fiber maturation, and neuron function and communication.

As of now, further studies are necessary to uncover the relationship between HBOT and neurocognitive functions concerning other types of strokes and anatomical locations. Read on as we summarize a 2020 Israeli research study, headed by Amir Hadanny at Sagol Center for Hyperbaric Medicine and Research and published in the journal Restorative Neurology and Neuroscience, that examined HBOT cognitive benefits during the late chronic stage of post-stroke individuals.

The Study’s Objective and Methods

The primary objective of the Israeli study was to determine the benefits of hyperbaric oxygen therapy for neurocognitive deficits using three analyses.

The first analysis compared ischemic and hemorrhage stroke origins alongside their anatomical locations. The second looked at the cortical and subcortical, two primary stroke locations, and the third used dominance analysis to reduce unknown hemisphere dominance by omitting left-handed patients.

The entire study also dismissed patients with inadequate stroke information, including not knowing the nature of the attack and not having proper HBOT cognitive evaluations before or after the study to test improvements. The study, which ran for almost ten years from January 2008 to December 2017, tested 162 patients, each with at least three months post-injury.

Before starting the study, doctors also collected patient medical records and divided the patients into groups based on the information. The stroke subsets included stroke origins, anatomical location, and affected brain hemisphere. Then, patients entered a multi-place hyperbaric chamber, beginning hyperbaric oxygen therapy for neurological conditions.

The protocol consisted of conducting treatments five days weekly with 100% oxygen levels at 2 ATA, each day requiring 40 to 60 90-minute sessions. Patients received five-minute rests every 20 minutes, where they breathed regular surrounding air before returning to the air machine.

Additional Read: How Hyperbaric Oxygen Therapy Can Diminish Fibromyalgia Syndrome

Results of the Study

Despite the anatomical location, affected brain side, or stroke type, 86% of all patients involved in hyperbaric oxygen therapy for cognitive impairment saw massive improvements. Both cortical and subcortical strokes lead to clinically significant improvements (CSI) defined with a >0.5 standard deviation. While all domains received positive results, the memory domain saw the highest post-score results between 2.34 and 20.

Ischemic Vs. Hemorrhagic Strokes

With overall cognitive changes of 94.6% and 83.33% with ischemic and hemorrhagic strokes, respectively, researchers observed no substantial differences between the two. The only cognitive domain that saw significant differences in CSI between the two was information processing speed. Ischemic stroke patients had a 1.36 mean score, and Hemorrhagic stroke patients exceeded that with a 5.39 mean score.

Still, researchers found no significant differences between global cognitive scale (GCS), memory, executive function (EF), attention, and motor skill. The mean score found among ischemic stroke patients, resting at 83.87, was barely higher than the 76.82 mean score of hemorrhagic stroke patients. Therefore, oxygen therapy benefits for brain improvements transcend stroke type, providing similar outcomes.

Cortical Vs. Subcortical

Stroke locations showed differences in more domains than stroke type during hyperbaric oxygen therapy for neurological conditions. For one, patients with strokes located within the cortical had a significantly higher speech statistic at 39 (50.6%) than patients with subcortical strokes with 15 (30%) CSI.

Subcortical strokes, however, provided better results with 92.37 EF and 88.44 attention domain improvements, contrary to cortically-located strokes with 85.19 EF and 80.78 attention improvement. Still, the overall CSI difference between both stroke locations is not worth noting, with a 90% CSI change in subcortical stroke patients and an 87.23% change in cortical stroke patients.

Brain Hemisphere Side

Finally, researchers completed the right-handed analysis of hyperbaric oxygen therapy for cognitive impairment. This comparison showed differences in motor and speech symptoms only when comparing dominant and subdominant stroke sides. Patients who obtained strokes on their non-dominant hand had a 50 or 89.3% improvement in motor skills compared to dominant side post-stroke patients with a 40 or 74.1% growth.

It was the opposite for speech symptoms since the dominant side showed better results at 30 or 55.6% compared to the 13 or 23.2% change in non-dominant sides. As with stroke types and locations, the brain hemisphere side did not turn up differences at the baseline level of cognitive function. The dominant side had a 90.57% overall CSI, and non-dominant right-side patients had a 76.47% CSI.

Limitations of The Study and Future Research Directions

Hyperbaric oxygen therapy for neurocognitive deficits proved oxygenation for post-stroke patients beneficial. However, some limitations restricted a complete understanding of HBOT, including inconsistent controlled factors.

In this study, some patients received up to 60 90-minute sessions daily, while others obtained the bare minimum of 40 daily sessions. Although patients from either session had strong CSI post-treatments, doctors did not test the differences between the two sessions to determine whether one surpassed the other. Therefore, it was unclear which produces optimal neuroplasticity with few side effects.

The study also failed to show long-term effects resulting from treatments. This missing data bars us from noting any further improvements post-treatment or regressive patterns within the primary cognitive domains. Therefore, we suggest future researchers consider long-term studies that monitor patients far beyond treatment time and refrain from using retrospective data.

How Hyperbaric Oxygen Therapy Could Be Useful in Improving Neurocognitive Functions

For doctors wondering how to prevent neurodegenerative diseases within patients, which cause cells in the nervous system and brain to deteriorate, limiting and eventually ceasing cognitive function, consider HBOT treatments. This HBOT study provided published statistics on the largest patient group population undergoing post-stroke treatment.

It uncovered promising results, proving this successful form of therapy sends increased amounts of oxygen to damaged or weakened tissues, healing them. Hence, cognitive domains reflect favorable CSI, allowing stroke patients to recover more than ever before within a short period.

Additional Read: Other Off-Label Conditions That Can Be Treated With Hyperbaric Oxygen Therapy

The Bottom Line

Since this study pulled no substantial differences in overall CSI when comparing stroke types, locations, and hemispheres, these factors shouldn’t determine patient eligibility for treatment. Instead, doctors should examine functional imaging, which measures major changes in function, including blood flow, chemical composition, and metabolism.

Doing so fully monitors positive or negative effects according to body reactions and tracks differences in baseline cognitive function. However, doctors should conduct further research into post-stroke patient treatment with oxygenation to determine patient eligibility and which patients will benefit most with few side effects.

For more on hyperbaric oxygen therapy for neurological conditions or to partner with us for optimal post-stroke patient care, contact NexGen Hyperbaric in Edwards, CO, at 888-567-4302 today.