Hyperbaric oxygen can induce neuroplasticity and improve cognitive functions of patients suffering from anoxic brain damage

Purpose: Cognitive impairment may occur in 42-50% of cardiac arrest survivors. Hyperbaric oxygen therapy (HBO₂) has recently been shown to have neurotherapeutic effects in patients suffering from chronic cognitive impairments (CCI) consequent to stroke and mild traumatic brain injury. The objective of this study was to assess the neurotherapeutic effect of HBO₂ in patients suffering from CCI due to cardiac arrest. Methods: Retrospective analysis of patients with CCI caused by cardiac arrest, treated with 60 daily sessions of HBO₂.Evaluation included objective computerized cognitive tests (NeuroTrax), Activity of Daily Living (ADL) and Quality of life questionnaires. The results of these tests were compared with changes in brain activity as assessed by single photon emission computed tomography (SPECT) brain imaging. Results: The study included 11 cases of CCI patients. Patients were treated with HBO₂, 0.5-7.5 years (mean 2.6±0.6 years) after the cardiac arrest. HBO₂ was found to induce modest, but statistically significant improvement in memory, attention and executive function (mean scores) of 12%, 20% and 24% respectively. The clinical improvements were found to be well correlated with increased brain activity in relevant brain areas as assessed by computerized analysis of the SPECT imaging. Conclusions: Although further research is needed, the results demonstrate the beneficial effects of HBO₂ on CCI in patients after cardiac arrest, even months to years after the acute event.