Neurological Conditions

Written By Elizabeth Gaffney

Hyperbaric Oxygen Therapy for Neurological Conditions

Introduction

Hyperbaric oxygen therapy (HBOT), in which the patient breathes pure oxygen in a pressurised chamber, may have wide-ranging benefits for patients with neurological disorders, including traumatic brain injury (TBI), Alzheimer’s disease and Parkinson’s disease. HBOT is associated with enhanced oxygen delivery, reduced inflammation and increased neuroplasticity and mitochondrial function. There is robust experimental and clinical evidence supporting HBOT as an adjunctive treatment for a range of neurological conditions.

Mechanism of Action

During HBOT, patients are treated with pure oxygen in a chamber in which the pressure is higher than atmospheric pressure (2 ATA) for 1.5 hours for multiple sessions. HBOT enhances oxygen delivery to tissues (Cannelotto et al., 2024), and the beneficial effects of HBOT on neurological conditions involve several distinct mechanisms.

1. Enhanced oxygen delivery to hypoxic neural tissue: One of the primary challenges in many neurological conditions, such as stroke and TBI, is hypoxic tissue within the brain. HBOT increases the amount of dissolved oxygen in plasma, delivering more oxygen to the brain (Nemoto & Betterman, 2007; Larsson et al., 2010). The increased oxygen availability promotes neuronal ATP production and mitochondrial function (Gottfried et al., 2021).

2. Reduction of inflammation and oxidative stress: Neurological conditions often involve an inflammatory response that exacerbates neuronal damage. HBOT attenuates inflammation by modulating immune cell activity, reducing the levels of pro-inflammatory cytokines (De Wolde et al., 2021). By reducing inflammation and oxidative stress, HBOT helps mitigate brain injury and protects neurons from further damage (Shapira et al., 2018; Fischer & Barak, 2020).

3. Neurogenesis and synaptic plasticity: HBOT may promote neurogenesis and synaptic plasticity (Hu et al., 2014; Efrati et al., 2013). One of the major pathways in HBOT-mediated neurogenesis and synaptic plasticity is the brain-derived neurotrophic factor (BDNF) pathway, which is essential for neural plasticity, learning, and memory (Bin-Alamer et al., 2024). In addition, HBOT can induce cerebral angiogenesis, leading to improved white and grey microstructures indicating regeneration of nerve fibres (Tal et al., 2017).

4. Reduced apoptosis and enhanced cellular repair: HBOT has anti-apoptotic effects, in damaged neural cells (Gottfried et al., 2021). By downregulating apoptosis-inducing factors, such as caspases and Bax proteins, HBOT promotes cellular survival and repair. These anti-apoptotic effects may protect against progressive cell loss in neurodegenerative diseases, where neuronal death is a hallmark feature.

5. Mitochondrial function: HBOT may improve mitochondrial biogenesis via the SIRT-1/PGC1-1a pathway (Hsu et al., 2022).

Benefits to Patients of HBOT for Neurological Conditions

HBOT is generally well tolerated, and serious side effects are rare (Camporesi, 2014; Zhang et al., 2023). Patients with neurological conditions may experience a range of benefits from HBOT that can significantly improve their symptoms and quality of life.

1. Improved cognitive and motor function: For patients who have experienced brain injuries or stroke, cognitive and motor impairments are often significant hurdles to recovery. HBOT is associated with improvements in memory, attention, and executive function, as well as motor coordination and strength (Daly et al., 2018; Rosario et al., 2018; Hadanny et al., 2020).

2. Reduction in pain and spasticity: Chronic pain and spasticity are common in conditions such as stroke and spinal cord injuries, often resulting from abnormal nerve signalling and inflammation. HBOT’s anti-inflammatory effects can alleviate these symptoms, reducing spasticity and enhancing patients’ comfort (Jain et al., 1989; Montgomery et al., 1999). Pain reduction can also lead to decreased reliance on medication, which is a significant benefit given the risks associated with long-term use.

3. Enhanced mood and psychological well-being: Patients with neurological conditions often experience mood disorders, including anxiety and depression, due to both biological factors and the impact of their symptoms on daily life. HBOT may alleviate depression (Liang et al., 2020) and improve quality-of-life scores (Rosario et al., 2018).

4. Potential for slowing disease progression: In neurodegenerative diseases, HBOT may slow disease progression by reducing oxidative stress and protecting against neuronal loss (Ahmadi & Khalatbary, 2021; Yang et al., 2024).

5. Reduced recovery time and hospitalisation: For acute neurological events, such as TBI, timely HBOT intervention may reduce the duration of hospital stays and accelerate recovery (Rockswold et al., 2001; Chen et al., 2022).

Clinical Evidence of HBOT for Neurological Conditions

Numerous studies, clinical trials and systematic reviews support the use of HBOT in the treatment of neurological conditions.

1. Meta-analyses and reviews: There have been several reviews and meta-analyses about the benefits and efficacy of HBOT for traumatic brain injury (Daly et al., 2018; Harch, 2022), Alzheimer’s disease (Somaa, 2021; Yang et al., 2023; Lin et al., 2024), vascular dementia (You et al., 2019; Balasubramanian et al., 2021) and Parkinson’s disease ((Bu et al., 2024; Tan et al., 2024) that have concluded that HBOT may be beneficial. For strokes, Bennett et al. (2014) and Ding et al. (2024) concluded that while HBOT may be beneficial, there is currently insufficient evidence to recommend HBOT for routine treatment.

2. Traumatic brain injury: Systematic reviews of HBOT for traumatic brain injury concluded that HBOT (100% O2, 1.5–2.5 ATA, 20–90 mins, 1–42 sessions) within 24 hours of TBI has the potential to be the first significant treatment in the acute phase of severe TBI (Daly et al, 2018) and, in patients with mild traumatic brain injury, HBOT at 1.5 ATA (40 sessions) leads to symptomatic and cognitive improvements (Harch, 2022). In a study of HBOT for the acute phase of TBI, patients started HBOT (100% O2, 2 ATA, 60 mins, 20 sessions) when their vital signs had stabilised (Chen et al., 2022). Consciousness, cognitive function, and prognosis recovery were improved in HBOT-treated patients compared to controls by decreasing TBI-induced haematoma volumes, promoting the recovery of EEG rhythm, and modulating the expression of serum biomarkers. In a study involving 37 severely brain-injured patients, HBOT (100% O2, 1.5 ATA, 60 mins, ≤7 sessions) reduced intracranial pressure, increased the cerebral metabolic rate of oxygen and decreased ventricular cerebrospinal fluid lactate, indicating that HBOT may enhance aerobic metabolism (Rockswold et al., 2001). In studies of patients with mild-to-moderate TBI, HBOT relieves persistent post-concussion syndrome in adults and children (Harch et al., 2017; Hadanny et al., 2022; Nelson et al., 2024).

3. Stroke: Reviews of the evidence of HBOT for stroke concluded that there is currently insufficient evidence to recommend HBOT for the treatment of strokes (Bennett et al., 2014; Ding et al., 2024). However, one systematic review and meta-analysis concluded that HBOT is beneficial for post-stroke depression, and patients undergoing HBOT monotherapy achieve a response as good or better than patients treated with antidepressants (Liang et al., 2020). In a clinical trial by Efrati et al. (2015), HBOT (100% O2, 2 ATA, 90 mins, 40 sessions) led to significant neurological improvements in post-stroke patients even at chronic late stages (up to 36 months).

4. Alzheimer’s disease: Narrative (Yang et al., 2023) and systematic (Lin et al., 2024) reviews conclude that HBOT is a safe and effective treatment for Alzheimer’s disease patients. The meta-analysis of Lin et al. (2024) included 11 RCTs and 847 participants and found that HBOT (typically 2 ATA, 80–120 mins, up to 130 sessions) can improve markers of cognitive function and decrease serum oxidative stress markers (MDA and SOD) and inflammatory cytokines (IL-1β and TGF-β1).

5. Vascular dementia: Several reviews and meta-analyses have systematically analysed the effect of HBOT on vascular cognitive impairment and dementia and concluded that HBOT can be recommended as an effective and safe complementary therapy for the treatment of dementia (You et al., 2019; Balasubramanian et al., 2021). The meta-analysis of You et al. (2019) included 25 randomised clinical trials and almost 2,000 patients and concluded that HBOT markedly improved the Mini-Mental State Examination (MMSE) scores, activities of daily living, and total efficacy rate, and that 7–8 weeks of 60-minute HBOT sessions produced the maximum therapeutic effect. A study by Xu et al. (2019) included 58 patients with vascular dementia randomly divided into control and HBOT (100% O2, 2 ATA, 60 mins, 60 sessions) groups. After the treatment period, patients receiving HBOT not only showed significantly higher MMSE scores but also higher serum humanin levels. Humanin is a mitochondrial-derived peptide with strong neuroprotective effects (Zárate et al., 2019) that prevents cognitive decline (Yen et al., 2018).

6. Parkinson’s disease: Recent systematic reviews concluded that HBOT has several clinical benefits for patients with Parkinson’s disease (Bu et al., 2024; Tan et al., 2024). In the meta-analysis of Bu et al. (2024), 13 studies and 958 participants were included, and the authors concluded that HBOT at 2–2.5 ATA improves motor function, relieves the severity of the disease, ameliorates cognitive function, and improves sleep quality while alleviating excessive daytime sleepiness in patients with Parkinson’s disease.

Conclusion

Overall, research indicates that HBOT can offer promising neuroprotective benefits for various neurological conditions, including TBI and neurodegenerative diseases. HBOT improves mitochondrial function, reduces neuroinflammation, and enhances oxygen delivery to hypoxic tissues. Clinical evidence, including randomised controlled trials, systematic reviews, and case reports, supports the benefits of HBOT for TBI, Alzheimer’s disease, vascular dementia and Parkinson’s disease, as well as potentially stroke.

References

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Elizabeth Gaffney https://www.sourceprojects.co
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