Hyperbaric Oxygen Therapy for Persistent Post Stroke Depression

Hyperbaric Oxygen Therapy for Persistent Post Stroke Depression: A Prospective, Randomized, Double Blind Study

The study evaluates the effect of HBOT on depression in patients suffering from persistent symptoms of post stroke depression (PSD) in an double blind sham control study.

Post-stroke depression (PSD) is a prevalent mental health complication, affecting approximately 33% of stroke survivors. Its occurrence not only hinders rehabilitation and recovery from motor and cognitive deficits post-stroke but also escalates the risk of subsequent neurovascular events. Both biological and psychological factors are instrumental in the onset of PSD.

Ischemia plays a pivotal role in the development of long-term PSD due to its impact on specific brain regions, neurotransmitter systems, neural connectivity, inflammatory responses, and mitochondrial dysfunction.

brain ischemia can instigate a protracted cycle of inflammation, levels and functions of neurotransmitters, impaired mitochondrial function, that directly impinges on the brain's ability to undergo neuroplastic changes. This relationship underscores the importance of targeting the cure of brain ischemia in therapeutic strategies for PSD. Managing the brain ischemia could potentially salvage neuroplasticity and mitigate the mental and cognitive decline associated with PSD.

The new protocols of hyperbaric oxygen therapy (HBOT), using the hyperoxic-hypoxic paradox (HHP), is one of the first therapeutic intervention already in clinical use today for the specific goal of inducing regeneration of damaged brain tissue.

Cumulative data from recent years provide convincing evidence that HBOT can induce neuroplasticity leading to repair of chronically impaired brain functions and improved quality of life in post-stroke patients.

Both neurological and cognitive functions were improved even years after the stroke.

The observed restoration of neuronal activity in the metabolically dysfunctional stunned areas indicates that HBOT is a potent means of delivering sufficient oxygen needed for activation of neuroplasticty and restoration of impaired functions.

HBOT was found to be effective in small clinical trials for patients suffering from post-stroke depression. In a meta-analysis done by Liang et al. the efficacy and safety of HBOT for PSD was evaluated. A total of 27 RCTs involving 2250 participants were identified. Patients in HBOT group had a higher response rate than patients in control group (response rate: 69.4% vs 51.2%, odds ratio [OR] = 2.51, 95% confidence interval [CI] [1.83-3.43], P = 0.000). HBOT significantly reduced Hamilton Depression (HAMD).

The aim of the current study is to evaluate the effect of HBOT on depression in patients suffering from persistent symptoms of post stroke depression (PSD) in an double blind sham control study.

Inclusion Criteria:

1. Age between 50 -85
2. Suffered an ischemic stroke 6 months to 7 years prior to their inclusion
3. Treated or being treated by antidepressants for at least 3 months
4. Diagnosis of PSD based on HDRS-17 score of 17 and above.
5. Stable psychological and pharmacological treatment for more than three months prior to inclusion.
6. Subject willing and able to read, understand and sign an informed consent.

Exclusion Criteria:

1. Inability to attend scheduled clinic visits and/or comply with the study protocol
2. Diagnosis of a psychiatric disorder prior to the recent stroke including: major depression, schizophrenia or bipolar disease.
3. Diagnosis of aphasia or major cognitive decline
4. History of Deep brain stimulation (DBS)
5. History of traumatic brain injury, brain tumors, brain surgery, chronic subdural haemorrhages, Epilepsy
6. Active malignancy
7. Substance use at baseline.
8. History of other neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), Lewy body dementia (LBD), Frontotemporal dementia (FTD), Multiple sclerosis (MS), Amyotrophic lateral sclerosis (ALS), Creutzfeld Jacob disease (CJD), Multisystem atrophy (MSA), Pseudobulbar palsy (PSP), Corticobasal degeneration (CBD), Wernicke Korsakoff syndrome
9. Serious suicidal ideation
10. Renal or liver insufficiency, electrolyte imbalances
11. Chronic heart failure with ejection fraction of 30 or less
12. HBOT for any reason prior to study enrolment
13. Chest pathology incompatible with pressure changes (including active asthma or COPD)
14. Ear or Sinus pathology incompatible with pressure changes (above 3 otolaryngologist visits a year)
15. An inability to perform an awake brain MRI
16. No evidence of vascular related lesions in the brain MRI
17. Active smoking
18. Participation in another study