Effects of hyperbaric oxygen therapy on functional and structural connectivity in post-COVID-19 condition patients: A randomized, sham-controlled trial

Therapeutic options for the treatment of post-acute sequelae of COVID-19: a scoping review

OBJECTIVES

This scoping review aimed to summarize the available studies to address the question of which therapeutic agents can be utilized for patients with post-acute sequelae of COVID-19 (PASC).

METHODS

We conducted a systematic search in medical databases, including PubMed and Embase, for studies aligned with our objectives published between January 1, 2020, and July 22, 2024. For each study, we summarized the main symptoms targeted, study design, therapeutic regimens, evaluation tools, and clinical outcomes.

RESULTS

A total of 413 studies were identified, and 39 studies were included in this review based on relevance to the research objectives. We primarily focused on high-level evidence studies, such as meta-analyses and randomized controlled trials, but observational studies were included when evidence was scarce. Therapeutic agents evaluated included hyperbaric oxygen, ivermectin, metformin, naltrexone, micronutrient supplements, antifibrotic agents, antiviral agents, and selective serotonin reuptake inhibitors (SSRIs). Among these, hyperbaric oxygen, antifibrotic agents, antiviral agents, and SSRIs demonstrated promising results. However, the heterogeneity of PASC symptoms posed challenges in synthesizing findings for specific symptom-based outcomes.

CONCLUSION

Given the heterogeneity of symptoms, this review highlights the need for standardized and targeted research to better address the diverse therapeutic needs of patients with PASC.

CLINICAL TRIAL

Not applicable.

A double-blind randomized trial of hyperbaric oxygen for persistent symptoms after brain injury

In this double-blind randomized trial, adults with persistent symptoms following non-stroke brain injury received 40 hyperbaric oxygen (HBO2) sessions or 40 sham sessions over 12 weeks. Three months later, all were offered 40 unblinded HBO2 sessions. Participants completed the Neurobehavioral Symptom Inventory (NSI) at baseline, 13 weeks (after 40 chamber sessions), 6 months, 9 months (after the second chamber series), and 12 months, with prime outcome at 13 weeks, and additional questionnaires, neuropsychological tests, and functional measures. We enrolled 49 participants and analyzed 47 due to drop-out/exclusion (26 males, 40 with traumatic brain injury). Baseline NSI was 35.9 ± 15.8 in the HBO2 group (n = 26) and 30.7 ± 16.9 in the sham group (n = 21) (p = 0.28). Mean 13-week change scores were 10.6 ± 10.6 (HBO2 group) and 3.6 ± 5.9 (sham group) (mean difference 7.0, 95% CI 1.7-12.3, p = 0.01). The HBO2 group improved on measures of olfaction, anxiety, sleep difficulties, and vestibular complaints. Both groups reported improvements in depression, headaches, PTSD symptoms, physical quality of life, and degree to which difficulties interfere with daily life. With an additional 40 HBO2 sessions, the original HBO2 group reported additional improvements on NSI at 12 months. Only 15 original sham participants completed the second chamber series, limiting conclusions from that data.

Advances in Neuroimaging and Deep Learning for Emotion Detection: A Systematic Review of Cognitive Neuroscience and Algorithmic Innovations

Background/Objectives: The following systematic review integrates neuroimaging techniques with deep learning approaches concerning emotion detection. It, therefore, aims to merge cognitive neuroscience insights with advanced algorithmic methods in pursuit of an enhanced understanding and applications of emotion recognition. Methods: The study was conducted following PRISMA guidelines, involving a rigorous selection process that resulted in the inclusion of 64 empirical studies that explore neuroimaging modalities such as fMRI, EEG, and MEG, discussing their capabilities and limitations in emotion recognition. It further evaluates deep learning architectures, including neural networks, CNNs, and GANs, in terms of their roles in classifying emotions from various domains: human-computer interaction, mental health, marketing, and more. Ethical and practical challenges in implementing these systems are also analyzed. Results: The review identifies fMRI as a powerful but resource-intensive modality, while EEG and MEG are more accessible with high temporal resolution but limited by spatial accuracy. Deep learning models, especially CNNs and GANs, have performed well in classifying emotions, though they do not always require large and diverse datasets. Combining neuroimaging data with behavioral and cognitive features improves classification performance. However, ethical challenges, such as data privacy and bias, remain significant concerns. Conclusions: The study has emphasized the efficiencies of neuroimaging and deep learning in emotion detection, while various ethical and technical challenges were also highlighted. Future research should integrate behavioral and cognitive neuroscience advances, establish ethical guidelines, and explore innovative methods to enhance system reliability and applicability.

Diffusion tensor imaging features of white matter pathways in the brain after COVID-19 infection

PURPOSE

To determine whether there is a difference in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values in white matter pathways in the subacute period after COVID-19 infection and to evaluate the correlation between diffusion tensor imaging (DTI) metrics and laboratory findings.

MATERIAL AND METHODS

The study included 64 healthy controls and 91 patients. Patients were classified as group 1 (all patients, n = 91), group 2 (outpatients, n = 58), or group 3 (inpatients, n = 33). The ADC and FA values were calculated from 10 distinct neuroanatomic localizations; DTI values were compared between groups.

RESULTS

Decreased FA values in the cingulum, corpus callosum splenium and genu (CCS-CCG), forceps major, inferior fronto-occipital fasciculus (IFOF), and middle cerebellar peduncle (MCP) observed in group 1 compared with the control group. Group 1 showed elevated ADC values in CCG. Lower FA and higher ADC values in CCG were shown in group 3. The FA values for CCS, IFOF, and MCP in group 3 were lower than those in the control group. Group 3 had the highest ADC values in the CCS. Additionally, the FA values of the CCG were lower in group 3 than in group 2. Oxygen saturation levels and FA values in the CCG and SFOF exhibited a positive correlation.

CONCLUSION

We speculate that DTI changes in white matter pathways may be associated with axonal damage and demyelination due to impaired white matter integrity following COVID-19 infection during the subacute period.

CLINICAL SIGNIFICANCE

Our study showed with DTI findings that there is microstructural damage in white matter pathways in the subacute period of COVID-19 infection and that this damage is related to oxygen saturation levels. Many studies in the literature show that microstructural damage in white matter pathways can lead to clinical neurocognitive dysfunction. We suggest that these cases require more comprehensive studies investigating whether chronic white matter damage is reversible and examining its relationship with neurocognitive dysfunctions in the future.

MAIN POINTS

Neurological involvement is not rare in COVID-19 infection. We examined various white matter pathways with DTI during the subacute period of COVID-19 infection. We showed changes in DTI parameters indicating a decrease in white matter integrity and microstructural damage in the subacute period follow-up of cases with COVID-19. We found that there was a positive correlation between oxygen saturation levels and decreased FA values in white matter tracts.

Tackling persistent neurological symptoms in patients following acute COVID-19 infection: an update of the literature

INTRODUCTION

The COVID-19 pandemic has taught myriad lessons and left several questions we are yet to comprehend. Initially, the scientific community was concerned with the management of acute disease and immunization. Once the peak of the pandemic receded, it became clear that a proportion of patients were far from fully recovered. Researchers started to recognize those persisting symptoms as a new entity termed 'Long COVID,' where neurological symptoms are evident and have a major impact on quality of life.

AREAS COVERED

The main purpose of this narrative review is to analyze and synthesize the current literature regarding Long COVID, its relation to the nervous system, and to explore the evidence on treatments for persistent neurological symptoms. The most common reported and observed neurologic manifestations include fatigue, cognitive impairment, pain, polyneuropathy, and neuropsychiatric disorders. A variety of pharmacologic and non-pharmacologic therapies have been evaluated and yielded mixed results. Many of them focused on immunomodulation and none currently have U.S. FDA approval.

EXPERT OPINION

Challenges remain in terms of clinical characterization and prognosis of Long COVID, besides understanding its pathophysiology. Standardization of biomarkers and diagnostic criteria will allow the use of common nomenclature and data elements in the design of future clinical studies.

Is there a rationale for hyperbaric oxygen therapy in the patients with Post COVID syndrome? : A critical review

The SARS-CoV-2 pandemic has resulted in 762 million infections worldwide from 2020 to date, of which approximately ten percent are suffering from the effects after infection in 2019 (COVID-19) [1, 40]. In Germany, it is now assumed that at least one million people suffer from post-COVID condition with long-term consequences. These have been previously reported in diseases like Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). Symptoms show a changing variability and recent surveys in the COVID context indicate that 10-30 % of outpatients, 50 to 70% of hospitalised patients suffer from sequelae. Recent data suggest that only 13% of all ill people were completely free of symptoms after recovery [3, 9]. Current hypotheses consider chronic inflammation, mitochondrial dysfunction, latent viral persistence, autoimmunity, changes of the human microbiome or multilocular sequelae in various organ system after infection. Hyperbaric oxygen therapy (HBOT) is applied since 1957 for heart surgery, scuba dive accidents, CO intoxication, air embolisms and infections with anaerobic pathogens. Under hyperbaric pressure, oxygen is physically dissolved in the blood in higher concentrations and reaches levels four times higher than under normobaric oxygen application. Moreover, the alternation of hyperoxia and normoxia induces a variety of processes at the cellular level, which improves oxygen supply in areas of locoregional hypoxia. Numerous target gene effects on new vessel formation, anti-inflammatory and anti-oedematous effects have been demonstrated [74]. The provision of intermittently high, local oxygen concentrations increases repair and regeneration processes and normalises the predominance of hyperinflammation. At present time only one prospective, randomized and placebo-controlled study exists with positive effects on global cognitive function, attention and executive function, psychiatric symptoms and pain interference. In conclusion, up to this date HBO is the only scientifically proven treatment in a prospective randomized controlled trial to be effective for cognitive improvement, regeneration of brain network and improvement of cardiac function. HBOT may have not only theoretical but also potential impact on targets of current pathophysiology of Post COVID condition, which warrants further scientific studies in patients.

Effect of Hyperbaric Oxygen Therapy on Patients with SARS-CoV-2 Infection: A Retrospective Cohort Study

Objective

The aim of this study was to evaluate the impact of hyperbaric oxygen therapy (HBOT) on patients with SARS-CoV-2 infection and determine its efficacy and safety in reducing treatment failure events.

Methods

A retrospective cohort study involving patients with COVID-19 was conducted. Inverse probability of treatment weighting (IPTW) was used to balance covariates between the HBOT and non-HBOT groups. The primary endpoint was the occurrence of a clinical treatment failure event, defined as all-cause mortality, abandonment of treatment, or transfer to the Intensive Care Unit due to worsening condition.

Results

A total of 720 patients with COVID-19 were enrolled in the study, with 27 patients receiving HBOT and 693 patients not receiving HBOT. The occurrence of treatment failure was significantly lower in the HBOT group compared to the non-HBOT group, with no treatment failure events in the HBOT group versus 36 events in the non-HBOT group. The IPTW database analysis results showed that in comparison to the non-HBOT group, the hazard ratio (HR) for treatment failure in the HBOT group was less than 0.001 (95% CI: <0.001 ~ <0.001, p<0.001). Lymphocyte count >0.8×109/L and HBOT was associated with a significantly lower risk of treatment failure. Glucocorticoid use was associated with a higher risk of treatment failure. The incidence of venous thrombosis events was significantly higher in the HBOT group compared to the non-HBOT group.

Conclusion

This study revealed that adjunctive HBOT significantly reduces the risk of treatment failure in patients with COVID-19 and is associated with satisfactory safety. HBOT shows promise as a beneficial therapy for improving outcomes in COVID-19-infected patients.

Research evidence on the management of the cognitive impairment component of the post-COVID condition: a qualitative systematic review

BACKGROUND

Cognitive impairment (CI) is one of the most prevalent and burdensome consequences of COVID-19 infection, which can persist up to months or even years after remission of the infection. Current guidelines on post-COVID CI are based on available knowledge on treatments used for improving CI in other conditions. The current review aims to provide an updated overview of the existing evidence on the efficacy of treatments for post-COVID CI.

METHODS

A systematic literature search was conducted for studies published up to December 2023 using three databases (PubMed-Scopus-ProQuest). Controlled and noncontrolled trials, cohort studies, case series, and reports testing interventions on subjects with CI following COVID-19 infection were included.

RESULTS

After screening 7790 articles, 29 studies were included. Multidisciplinary approaches, particularly those combining cognitive remediation interventions, physical exercise, and dietary and sleep support, may improve CI and address the different needs of individuals with post-COVID-19 condition. Cognitive remediation interventions can provide a safe, cost-effective option and may be tailored to deficits in specific cognitive domains. Noninvasive brain stimulation techniques and hyperbaric oxygen therapy showed mixed and preliminary results. Evidence for other interventions, including pharmacological ones, remains sparse. Challenges in interpreting existing evidence include heterogeneity in study designs, assessment tools, and recruitment criteria; lack of long-term follow-up; and under-characterization of samples in relation to confounding factors.

CONCLUSIONS

Further research, grounded on shared definitions of the post-COVID condition and on the accurate assessment of COVID-related CI, in well-defined study samples and with longer follow-ups, is crucial to address this significant unmet need.

Randomized Controlled Trials for Post-COVID-19 Conditions: A Systematic Review

Post-coronavirus disease 2019 (COVID-19) syndrome or condition (PCS) is defined as new onset symptoms for at least three months following COVID-19 infection that has persisted for at least two months. Given the global sequelae of COVID-19, there is an urgent need for effective PCS interventions. The aim of this study was to systematically review all interventions for PCS tested in randomized controlled trials. In this International Prospective Register of Systematic Reviews (PROSPERO) registered (CRD42023415835) systematic review, PubMed, Google Scholar, and ClinicalTrials.gov databases were searched between 1st January 2020 and 30th April 2023. Inclusion criteria were (1) randomized controlled trials that tested interventions for (2) PCS as defined above. Studies were independently reviewed, and final decisions regarding extracted data and risk of bias were made by consensus. Trial findings were summarized qualitatively. The review included 23 trials with 1,916 subjects (mean age 44.9, 25.8% males) from 10 countries. The predominant symptom or function targeted by the interventions were general long COVID-19 symptoms (35%), fatigue (30%), breathlessness (17%), olfactory (17%), and brain function (9%). Overall, the majority of trials (74%) were at high risk of bias. A range of interventions were identified, including physical therapies, dietary and regenerative treatments, electrical stimulation, and digital wellness programs with variable effects. While a diverse range of interventions for PCS have been tested, their effectiveness varies, with threats to validity in most studies. Trials focusing on PCS mental health disorders, musculoskeletal complaints, and children are needed. Well-designed RCTs are needed to establish definitive interventions for PCS.

Post-COVID-19 conditions: a systematic review on advanced magnetic resonance neuroimaging findings

Post-COVID conditions (PCCs) cover a wide spectrum of lingering symptoms experienced by survivors of coronavirus disease 2019 (COVID-19). Neurological and neuropsychiatric sequelae are common in PCCs. Advanced magnetic resonance imaging (MRI) techniques can reveal subtle alterations in brain structure, function, and perfusion that underlie these sequelae. This systematic review aimed to synthesize findings from studies that used advanced MRI to characterize brain changes in individuals with PCCs. A detailed literature search was conducted in the PubMed and Scopus databases to identify relevant studies that used advanced MRI modalities, such as structural MRI (sMRI), diffusion tensor imaging (DTI), functional MRI (fMRI), and perfusion-weighted imaging (PWI), to evaluate brain changes in PCCs. Twenty-five studies met the inclusion criteria, comprising 1219 participants with PCCs. The most consistent findings from sMRI were reduced gray matter volume (GMV) and cortical thickness (CTh) in cortical and subcortical regions. DTI frequently reveals increased mean diffusivity (MD), radial diffusivity (RD), and decreased fractional anisotropy (FA) in white matter tracts (WMTs) such as the corpus callosum, corona radiata, and superior longitudinal fasciculus. fMRI demonstrated altered functional connectivity (FC) within the default mode, salience, frontoparietal, somatomotor, subcortical, and cerebellar networks. PWI showed decreased cerebral blood flow (CBF) in the frontotemporal area, thalamus, and basal ganglia. Advanced MRI shows changes in the brain networks and regions of the PCCs, which may cause neurological and neuropsychiatric problems. Multimodal neuroimaging may help understand brain-behavior relationships. Longitudinal studies are necessary to better understand the progression of these brain anomalies.

Effects of Hyperbaric Oxygen Therapy on Long COVID: A Systematic Review

The coronavirus disease (COVID-19) pandemic has resulted in an increasing population that is experiencing a wide range of long-lasting symptoms after recovery from the acute infection. Long COVID refers to this specific condition and is associated with diverse symptoms, such as fatigue, myalgias, dyspnea, headache, cognitive impairment, neurodegenerative symptoms, anxiety, depression, and a sense of despair. The potential of hyperbaric oxygen therapy (HBOT) to improve chronic fatigue, cognitive impairments, and neurological disorders has been established; therefore, the use of HBOT to treat long COVID has also been studied. We conducted a literature search between 1 January 2019 and 30 October 2023, focusing on the clinical efficacy and utility of HBOT for treating long COVID and found ten clinical studies that fit the review topic, including one case report, five one-group pretest-posttest design studies, one safety report from a randomized controlled trial (RCT), and three complete reports of RCTs. Most studies found that HBOT can improve quality of life, fatigue, cognition, neuropsychiatric symptoms, and cardiopulmonary function. Although HBOT has shown some benefits for long COVID symptoms, further rigorous large-scale RCTs are required to establish precise indications, protocols, and post-treatment evaluations.

Advanced magnetic resonance neuroimaging techniques: feasibility and applications in long or post-COVID-19 syndrome - a review

Long-term or post-COVID-19 syndrome (PCS) is a condition that affects people infected with SARS‑CoV‑2, the virus that causes COVID-19. PCS is characterized by a wide range of persistent or new symptoms that last months after the initial infection, such as fatigue, shortness of breath, cognitive dysfunction, and pain. Advanced magnetic resonance (MR) neuroimaging techniques can provide valuable information on the structural and functional changes in the brain associated with PCS as well as potential biomarkers for diagnosis and prognosis. In this review, we discuss the feasibility and applications of various advanced MR neuroimaging techniques in PCS, including perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), functional MR imaging (fMRI), diffusion tensor imaging (DTI), and tractography. We summarize the current evidence on neuroimaging findings in PCS, the challenges and limitations of these techniques, and the future directions for research and clinical practice. Although still uncertain, advanced MRI techniques show promise for gaining insight into the pathophysiology and guiding the management of COVID-19 syndrome, pending larger validation studies.

Pulsed Hyperoxia Acts on Plasmatic Advanced Glycation End Products and Advanced Oxidation Protein Products and Modulates Mitochondrial Biogenesis in Human Peripheral Blood Mononuclear Cells: A Pilot Study on the "Normobaric Oxygen Paradox"

The "normobaric oxygen paradox" (NOP) describes the response to the return to normoxia after a hyperoxic event, sensed by tissues as an oxygen shortage, up-regulating redox-sensitive transcription factors. We have previously characterized the time trend of oxygen-sensitive transcription factors in human PBMCs, in which the return to normoxia after 30% oxygen is sensed as a hypoxic trigger, characterized by hypoxia-induced factor (HIF-1) activation. On the contrary, 100% and 140% oxygen induce a shift toward an oxidative stress response, characterized by NRF2 and NF-kB activation in the first 24 h post exposure. Herein, we investigate whether this paradigm triggers Advanced Glycation End products (AGEs) and Advanced Oxidation Protein Products (AOPPs) as circulating biomarkers of oxidative stress. Secondly, we studied if mitochondrial biogenesis was involved to link the cellular response to oxidative stress in human PBMCs. Our results show that AGEs and AOPPs increase in a different manner according to oxygen dose. Mitochondrial levels of peroxiredoxin (PRX3) supported the cellular response to oxidative stress and increased at 24 h after mild hyperoxia, MH (30% O2), and high hyperoxia, HH (100% O2), while during very high hyperoxia, VHH (140% O2), the activation was significantly high only at 3 h after oxygen exposure. Mitochondrial biogenesis was activated through nuclear translocation of PGC-1α in all the experimental conditions. However, the consequent release of nuclear Mitochondrial Transcription Factor A (TFAM) was observed only after MH exposure. Conversely, HH and VHH are associated with a progressive loss of NOP response in the ability to induce TFAM expression despite a nuclear translocation of PGC-1α also occurring in these conditions. This study confirms that pulsed high oxygen treatment elicits specific cellular responses, according to its partial pressure and time of administration, and further emphasizes the importance of targeting the use of oxygen to activate specific effects on the whole organism.

Long term outcomes of hyperbaric oxygen therapy in post covid condition: longitudinal follow-up of a randomized controlled trial

In our previous randomized controlled trial, we documented significant improvements in cognitive, psychiatric, fatigue, sleep, and pain symptoms among long Coronavirus disease 2019 (COVID) patients who underwent hyperbaric oxygen therapy (HBOT). The primary objective of the present study was to evaluate the enduring 1 year long term effects of HBOT on long COVID syndrome. This longitudinal long-term follow-up included 31 patients with reported post COVID-19 cognitive symptoms, who underwent 40 daily sessions of HBOT. Participants were recruited more than one year (486 ± 73) after completion of the last HBOT session. Quality of life, assessed using the short form-36 (SF-36) questionnaire revealed, that the long-term results exhibited a similar magnitude of improvement as the short-term outcomes following HBOT across most domains. Regarding sleep quality, improvements were observed in global score and across five sleep domains with effect sizes of moderate magnitude during the short-term evaluation, and these improvements persisted in the long-term assessment (effect size (ES1) = 0.47-0.79). In the realm of neuropsychiatric symptoms, as evaluated by the brief symptom inventory-18 (BSI-18), the short-term assessment following HBOT demonstrated a large effect size, and this effect persisted at the long-term evaluation. Both pain severity (ES1 = 0.69) and pain interference (ES1 = 0.83), had significant improvements during the short-term assessment post HBOT, which persisted at long term. The results indicate HBOT can improve the quality of life, quality of sleep, psychiatric and pain symptoms of patients suffering from long COVID. The clinical improvements gained by HBOT are persistent even 1 year after the last HBOT session.

Hyperbaric oxygen effectively addresses the pathophysiology of long COVID: clinical review

Background

The World Health Organization defines long COVID as "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation." Estimations of approximately 50 million individuals suffer from long COVID, reporting low health-related quality of life. Patients develop ongoing persistent symptoms that continue for more than 12 weeks that are not explained by another alternative diagnosis. To date, no current therapeutics are effective in treating the underlying pathophysiology of long COVID.

Discussion

A comprehensive literature search using PubMed and Google Scholar was conducted and all available articles from November 2021 to January 2024 containing keywords long covid and hyperbaric oxygen were reviewed. These published studies, including case series and randomized trials, demonstrate that utilizing Hyperbaric Oxygen Therapy (HBO) provided significant improvement in patients with long COVID.

Conclusion

A large cohort of patients suffer from long COVID or post-COVID-19 syndrome after recovery from their acute infection with no effective treatment options. HBO is a safe treatment and may provide benefit for this population and should continue to be researched for adjunctive treatment of long COVID.

Hyperbaric Oxygen Treatment for Long COVID: From Molecular Mechanism to Clinical Practice

Long COVID symptoms typically occur within 3 months of an initial COVID-19 infection, last for more than 2 months, and cannot be explained by other diagnoses. The most common symptoms include fatigue, dyspnea, coughing, and cognitive impairment. The mechanisms of long COVID are not fully understood, but several hypotheses have been put forth. These include coagulation and fibrosis pathway activation, inflammatory and autoimmune manifestations, persistent virus presence, and Epstein-Barr virus reactivation. Hyperbaric oxygen therapy (HBOT) is a therapeutic method in which a person inhales 100% oxygen under pressure greater than that of the atmosphere. HBOT has some therapeutic effects, including improvement of microcirculation, inhibition of cytokine release leading to a reduction in inflammatory responses, inhibition of autoimmune responses, and promotion of neurological repair. Several clinical trials have been carried out using HBOT to treat long COVID. The results suggest that HBOT helps to improve symptom severity, reduce symptom duration, and enhance patients' quality of life. It is believed that HBOT is an effective option for patients with long COVID, which is worth actively promoting.

Treatable traits for long COVID

Long COVID, or post-acute COVID-19 sequelae, is experienced by an estimated one in eight adults following acute COVID-19. Long COVID is a new and complex chronic health condition that typically includes multiple symptoms that cross organ systems and fluctuate over time; a one-size-fits-all approach is, therefore, not likely to be appropriate nor relevant for long COVID treatment. 'Treatable Traits' is a personalized medicine approach, purpose-built to address the complexity and heterogeneity of complex chronic conditions. This comprehensive review aimed to understand how a treatable traits approach could be applied to long COVID, by first identifying the most prevalent long COVID treatable traits and then the available evidence for strategies to target these traits. An umbrella review of 22 systematic reviews identified 34 symptoms and complications common with long COVID, grouped into eight long COVID treatable trait clusters: neurological, chest, psychological, pain, fatigue, sleep impairment, functional impairment and other. A systematic review of randomized control trials identified 18 studies that explored different intervention approaches for long COVID prevention (k = 4) or management (k = 14). While a single study reported metformin as effective for long COVID prevention, the findings need to be replicated and consensus is required around how to define long COVID as a clinical trial endpoint. For long COVID management, current evidence supports exercise training or respiratory muscle training for long COVID treatable traits in the chest and functional limitation clusters. While there are studies exploring interventions targeting other long COVID treatable traits, further high-quality RCTs are needed, particularly targeting treatable traits in the clusters of fatigue, psychological, pain and sleep impairment.

Functional MRI evaluation of hyperbaric oxygen therapy effect on hand motor recovery in a chronic post-stroke patient: a case report and physiological discussion

Introduction

Impairments in activities of daily living (ADL) are a major concern in post-stroke rehabilitation. Upper-limb motor impairments, specifically, have been correlated with low quality of life. In the current case report, we used both task-based and resting state functional MRI (fMRI) tools to investigate the neural response mechanisms and functional reorganization underlying hyperbaric oxygen therapy (HBOT)-induced motor rehabilitation in a chronic post-stroke patient suffering from severe upper-limb motor impairment.

Methods

We studied motor task fMRI activation and resting-state functional connectivity (rsFC) in a 61-year-old right-handed male patient who suffered hemiparesis and physical weakness in the right upper limb, 2 years after his acute insult, pre- and post-treatment of 60 daily HBOT sessions. Motor functions were assessed at baseline and at the end of the treatment using the Fugl-Meyer assessment (FMA) and the handgrip maximum voluntary contraction (MVC).

Results

Following HBOT, the FMA score improved from 17 (severe impairment) to 31 (moderate impairment). Following the intervention during trials involving the affected hand, there was an observed increase in fMRI activation in both the supplementary motor cortex (SMA) and the premotor cortex (PMA) bilaterally. The lateralization index (LI) decreased from 1 to 0.63, demonstrating the recruitment of the contralesional hemisphere. The region of interest, ROI-to-ROI, analysis revealed increased post-intervention inter-hemispheric connectivity (P = 0.002) and a between-network connectivity increase (z-score: 0.35 ± 0.21 to 0.41 ± 0.21, P < 0.0001). Seed-to-voxel-based rsFC analysis using the right SMA as seed showed increased connectivity to the left posterior parietal cortex, the left primary somatosensory cortex, and the premotor cortex.

Conclusion

This study provides additional insights into HBOT-induced brain plasticity and functional improvement in chronic post-stroke patients.

Immediate and Long-Term Effects of Hyperbaric Oxygenation in Patients with Long COVID-19 Syndrome Using SF-36 Survey and VAS Score: A Clinical Pilot Study

(1) Background: Long COVID syndrome (LCS) is a heterogeneous long-standing condition following COVID-19 infection. Treatment options are limited to symptomatic measures, and no specific medication has been established. Hyperbaric oxygenation (HBO) has been found to have a positive impact on the treatment of COVID-19 infection. This study evaluates both the feasibility and outcome of supportive HBO in patients with LCS. (2) Methods: Within 17 months, 70 patients with proven LCS were prospectively included. Each patient underwent a cycle of 10 subsequent HBO treatment sessions administered for 75 min at 2.2 atmospheres. Evaluation of the patients was performed before the first and after the last HBO session and 3 months afterwards. Statistical evaluation was based on an intention-to-treat analysis using Fisher's exact test and Student's t-test for paired samples. (3) Results: In total, 59 patients (33 females, 26 males; mean age: 43.9 years; range: 23-74 years; median: 45.0) were evaluable. After HBO, a statistically significant improvement of physical functioning (p < 0.001), physical role (p = 0.01), energy (p < 0.001), emotional well-being (p < 0.001), social functioning (p < 0.001), pain (p = 0.01) and reduced limitation of activities (p < 0.001) was confirmed. (4) Conclusions: Physical functioning and both the physical and emotional role improved significantly and sustainably, suggesting HBO as a promising supportive therapeutic tool for the treatment of LCS.

Olfactory Loss and Brain Connectivity after COVID-19: Structural Follow-Up at One Year

The structural connectivity from the primary olfactory cortex to the main secondary olfactory areas was previously reported as relatively increased in the medial orbitofrontal cortex in a cohort of 27 recently SARS-CoV-2-infected (COV+) subjects, of which 23/27 had clinically confirmed olfactory loss, compared to 18 control (COV-) normosmic subjects, who were not previously infected. To complement this finding, here we report the outcome of an identical high angular resolution diffusion MRI analysis on follow-up data sets collected in 18/27 COV+ subjects (10 males, mean age ± SD: 38.7 ± 8.1 years) and 10/18 COV- subjects (5 males, mean age ± SD: 33.1 ± 3.6 years) from the previous samples who repeated both the olfactory functional assessment and the MRI examination after ~1 year. By comparing the newly derived subgroups, we observed that the increase in the structural connectivity index of the medial orbitofrontal cortex was not significant at follow-up, despite 10/18 COV+ subjects were still found hyposmic after ~1 year from SARS-CoV-2 infection. We concluded that the relative hyperconnectivity of the olfactory cortex to the medial orbitofrontal cortex could be, at least in some cases, an acute or reversible phenomenon linked to the recent SARS-CoV-2 infection with associated olfactory loss.