Detrimental effects of COVID-19 in the brain and therapeutic options for long COVID: The role of Epstein–Barr virus and the gut–brain axis

Abstract:

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in a serious public health burden worldwide. In addition to respiratory, heart, and gastrointestinal symptoms, patients infected with SARS-CoV-2 experience a number of persistent neurological and psychiatric symptoms, known as long COVID or “brain fog”. Studies of autopsy samples from patients who died from COVID-19 detected SARS-CoV-2 in the brain. Furthermore, increasing evidence shows that Epstein–Barr virus (EBV) reactivation after SARS-CoV-2 infection might play a role in long COVID symptoms.

Moreover, alterations in the microbiome after SARS-CoV-2 infection might contribute to acute and long COVID symptoms. In this article, the author reviews the detrimental effects of COVID-19 on the brain, and the biological mechanisms (e.g., EBV reactivation, and changes in the gut, nasal, oral, or lung microbiomes) underlying long COVID.

In addition, the author discusses potential therapeutic approaches based on the gut–brain axis, including plant-based diet, probiotics and prebiotics, fecal microbiota transplantation, and vagus nerve stimulation, and sigma-1 receptor agonist fluvoxamine.

Source: Hashimoto, K. Detrimental effects of COVID-19 in the brain and therapeutic options for long COVID: The role of Epstein–Barr virus and the gut–brain axis. Mol Psychiatry (2023). https://doi.org/10.1038/s41380-023-02161-5 https://www.nature.com/articles/s41380-023-02161-5 (Full text)

A Pilot Study of Short-Course Oral Vitamin A and Aerosolised Diffuser Olfactory Training for the Treatment of Smell Loss in Long COVID

Abstract:

Background: Olfactory dysfunction (OD) is a common neurosensory manifestation in long COVID. An effective and safe treatment against COVID-19-related OD is needed.
Methods: This pilot trial recruited long COVID patients with persistent OD. Participants were randomly assigned to receive short-course (14 days) oral vitamin A (VitA; 25,000 IU per day) and aerosolised diffuser olfactory training (OT) thrice daily (combination), OT alone (standard care), or observation (control) for 4 weeks. The primary outcome was differences in olfactory function by butanol threshold tests (BTT) between baseline and end-of-treatment. Secondary outcomes included smell identification tests (SIT), structural MRI brain, and serial seed-based functional connectivity (FC) analyses in the olfactory cortical network by resting-state functional MRI (rs–fMRI).
Results: A total of 24 participants were randomly assigned to receive either combination treatment (n = 10), standard care (n = 9), or control (n = 5). Median OD duration was 157 days (IQR 127–175). Mean baseline BTT score was 2.3 (SD 1.1). At end-of-treatment, mean BTT scores were significantly higher for the combination group than control (p < 0.001, MD = 4.4, 95% CI 1.7 to 7.2) and standard care (p = 0.009) groups. Interval SIT scores increased significantly (p = 0.009) in the combination group. rs–fMRI showed significantly higher FC in the combination group when compared to other groups. At end-of-treatment, positive correlations were found in the increased FC at left inferior frontal gyrus and clinically significant improvements in measured BTT (r = 0.858, p < 0.001) and SIT (r = 0.548, p = 0.042) scores for the combination group.
Conclusions: Short-course oral VitA and aerosolised diffuser OT was effective as a combination treatment for persistent OD in long COVID.
Source: Chung TW-H, Zhang H, Wong FK-C, Sridhar S, Lee TM-C, Leung GK-K, Chan K-H, Lau K-K, Tam AR, Ho DT-Y, et al. A Pilot Study of Short-Course Oral Vitamin A and Aerosolised Diffuser Olfactory Training for the Treatment of Smell Loss in Long COVID. Brain Sciences. 2023; 13(7):1014. https://doi.org/10.3390/brainsci13071014 https://www.mdpi.com/2076-3425/13/7/1014 (Full text)

The potential role of Rhodiola rosea L. extract WS® 1375 for patients with post-COVID-19 fatigue

Abstract:

Fatigue and physical exhaustion are the dominant symptoms of post-coronavirus (COVID-19) conditions that might even develop after only mild acute disease. Post-acute infection syndromes have been observed after various infections, e.g., Coxiella burnetii, Ebola, Dengue, Polio, severe acute respiratory syndrome (SARS), Chikungunya, West Nile Virus, Borrelia, or Giardina lamblia. The similarities in symptoms and courses suggest a high likelihood of common pathogenetic pathways, including persistent infection, autoimmune reactions, dysregulation of the microbiome, inability to repair tissue damage, or endothelial dysfunction.

Some herbal drugs, so-called adaptogens, exert effects resulting in an increase in the resistance or regulatory potential of organisms against biological, chemical and physical burden or stress. Therefore, it seems possible that adaptogens can be helpful in cases of post-COVID-19 symptoms. One of these adaptogens is Rhodiola rosea L. The proprietary ethanolic extract made from roots and rhizomes of Rhodiola rosea WS® 1375 has been reported to modulate neuroinflammation in response to stress stimuli in preclinical models. Moreover, it activated the synthesis or resynthesis of adenosine triphosphate (ATP) in skeletal muscle mitochondria and counteracted muscle fatigue.

In three clinical trials with subjects suffering from burnout symptoms, prolonged or chronic fatigue symptoms or life-stress symptoms, clinically relevant improvements of fatigue and exhaustion were reported over 4 to 12 weeks of treatment at a very favorable tolerability and safety profile in heterogeneous patient populations. In conclusion, Rhodiola rosea extract WS® 1375 has a promising pharmacological and therapeutic profile for the treatment of fatigue and physical exhaustion associated with post-COVID-19 conditions.

Source: Wegener T, Edwards D, Kasper S. The potential role of Rhodiola rosea L. extract WS® 1375 for patients with post-COVID-19 fatigue. hb TIMES Schw Aerztej. 2023;8(1):56-61. doi:10.36000/hbT.2023.09.001 https://schw-aerztej.healthbooktimes.org/article/74319-the-potential-role-of-rhodiola-rosea-l-extract-ws-1375-for-patients-with-post-covid-19-fatigue (Full text)

Chronic inflammation, neuroglia dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

Highlights:

  • Plasmalogens (Pls) are lipids containing a vinyl-ether bond in their glycerol backbone
  • Pls have antioxidant properties and are important for curved membrane assemblies
  • Post-COVID-19 symptoms are highly prevalent and share several features with ME/CFS
  • Pls depletion is a shared biological hallmark of ME/CFS and acute COVID-19 syndrome
  • Pls replacement is a promising tool against neuroinflammation in these two conditions

Abstract:

After five waves of COVID-19 outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties (“brain fog”), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions.

Of great interest, recent evidence revealed a significant reduction of plasmalogens contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms.

Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Source: Chaves AM, Braniff O, Angelova A, Deng Y, Tremblay MÈ. Chronic inflammation, neuroglia dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome. Brain Res Bull. 2023 Jul 7:110702. doi: 10.1016/j.brainresbull.2023.110702. Epub ahead of print. PMID: 37423295. https://www.sciencedirect.com/science/article/pii/S0361923023001272?via%3Dihub (Full text)

The Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Long Covid: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog

Abstract:

Long Covid is a heterogeneous clinical condition in which Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and brain fog stand out among the different clinical symptoms and syndromes. The cerebral metabolic alterations and neuroendocrine disorders seem to constitute an important part of Long Covid.

Given the substantial lack of drugs and effective therapeutic strategies, hypothalamic phospholipid liposomes which have been on the market for several years as adjuvant therapy of cerebral metabolic alterations resulting from neuroendocrine disorders, can be taken into consideration in an overall therapeutic strategy that aims to control the Long Covid associated symptoms and syndromes. Their pharmacological mechanisms and clinical effects strongly support their usefulness in Long Covid. Our initial clinical experience corroborates this rationale. Further research is imperative in order to obtain robust clinical evidence.

Source: Menichetti, F. The Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Long Covid: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog. Preprints.org 2023, 2023070005. https://doi.org/10.20944/preprints202307.0005.v1 https://www.preprints.org/manuscript/202307.0005/v1 (Full text available as PDF file)

Long COVID treated successfully with antivirals in a rituximab-treated follicular lymphoma patient with persistent negative-antibodies to SARS-CoV2

Abstract:

Long COVID is a well-known complication to COVID-19 that affect millions of people worldwide and causes wide range of symptoms. We present a rare case of a previously diagnosed follicular lymphoma patient, who had a long COVID with persistent negative SARS-CoV-2 antibodies and required an aggressive antiviral treatment.

Source: Tayar E, Isber R, Isber N. Long COVID treated successfully with antivirals in a rituximab-treated follicular lymphoma patient with persistent negative-antibodies to SARS-CoV2. Heliyon. 2023 Jun;9(6):e17149. doi: 10.1016/j.heliyon.2023.e17149. Epub 2023 Jun 21. PMID: 37378376; PMCID: PMC10284434. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10284434/ (Full text)

Etiopathogenic theories about long COVID

Abstract:

The main etiopathogenic theories of long coronavirus disease (COVID) are listed and a conjunction of them is carried out with the objective of deciphering the pathophysiology of the entity, finally the main lines of treatment existing in real life are discussed (Paxlovid, use of antibiotics in dysbiosis, triple anticoagulant therapy, temelimab).

Source: Del Carpio-Orantes L. Etiopathogenic theories about long COVID. World J Virol. 2023 Jun 25;12(3):204-208. doi: 10.5501/wjv.v12.i3.204. PMID: 37396704; PMCID: PMC10311581. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10311581/ (Full text)

Long COVID and possible preventive options

Abstract:

Most of the people who suffered from COVID-19 fully recovered, but approximately 10–20% of them developed a wide variety of symptoms after they recover from their initial illness. Long COVID can develop at any patient; however, several studies suggest that the development of Long Covid syndrome may be linked to severity of acute illness.

Some of the risk factors are hospitalization (with mechanical ventilation), Intensive Care Unit admission, age (over 50 years), gender (female) and comorbidities. Since the precise mechanism of Long COVID has not been clarified, neither the management of Long COVID-19 syndrome has been solved yet.

Promising results have been published with vaccines as they effectively reduced the risk of Long COVID; however, other data suggest that vaccination results only partial protection in the post-acute phase of the disease. Recently, the orally effective antiviral agents (Paxlovid, molnupiravir) are preferred for outpatient management, and they highly reduce the progression of mild-to-moderate COVID-19 to severe one, and consequently, might reduce the development of Long COVID. Finally, recently, several clinical trials are in progress with either dietary supplements or drugs with different mechanisms of action.

Additional information on the precise mechanisms, risk factors of Long COVID may result in successful preventive and therapeutic management of Long Covid 19 syndrome.

Source: Sebők S, Gyires K. Long COVID and possible preventive options. Inflammopharmacology. 2023 Jun 21. doi: 10.1007/s10787-023-01204-1. Epub ahead of print. PMID: 37344737. https://link.springer.com/article/10.1007/s10787-023-01204-1 (Full text)

Oligosaccharides as Potential Regulators of Gut Microbiota and Intestinal Health in Post-COVID-19 Management

Abstract:

The COVID-19 pandemic has had a profound impact worldwide, resulting in long-term health effects for many individuals. Recently, as more and more people recover from COVID-19, there is an increasing need to identify effective management strategies for post-COVID-19 syndrome, which may include diarrhea, fatigue, and chronic inflammation. Oligosaccharides derived from natural resources have been shown to have prebiotic effects, and emerging evidence suggests that they may also have immunomodulatory and anti-inflammatory effects, which could be particularly relevant in mitigating the long-term effects of COVID-19.

In this review, we explore the potential of oligosaccharides as regulators of gut microbiota and intestinal health in post-COVID-19 management. We discuss the complex interactions between the gut microbiota, their functional metabolites, such as short-chain fatty acids, and the immune system, highlighting the potential of oligosaccharides to improve gut health and manage post-COVID-19 syndrome. Furthermore, we review evidence of gut microbiota with angiotensin-converting enzyme 2 expression for alleviating post-COVID-19 syndrome.

Therefore, oligosaccharides offer a safe, natural, and effective approach to potentially improving gut microbiota, intestinal health, and overall health outcomes in post-COVID-19 management.

Source: Cheong KL, Chen S, Teng B, Veeraperumal S, Zhong S, Tan K. Oligosaccharides as Potential Regulators of Gut Microbiota and Intestinal Health in Post-COVID-19 Management. Pharmaceuticals (Basel). 2023 Jun 9;16(6):860. doi: 10.3390/ph16060860. PMID: 37375807; PMCID: PMC10301634. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10301634/ (Full text)

Scientific Rationale for the Treatment of Cognitive Deficits from Long COVID

Abstract:

Sustained cognitive deficits are a common and debilitating feature of “long COVID”, but currently there are no FDA-approved treatments. The cognitive functions of the dorsolateral prefrontal cortex (dlPFC) are the most consistently afflicted by long COVID, including deficits in working memory, motivation, and executive functioning. COVID-19 infection greatly increases kynurenic acid (KYNA) and glutamate carboxypeptidase II (GCPII) in brain, both of which can be particularly deleterious to PFC function.
KYNA blocks both NMDA and nicotinic-alpha-7 receptors, the two receptors required for dlPFC neurotransmission, and GCPII reduces mGluR3 regulation of cAMP-calcium-potassium channel signaling, which weakens dlPFC network connectivity and reduces dlPFC neuronal firing. Two agents approved for other indications may be helpful in restoring dlPFC physiology: the antioxidant N-acetyl cysteine inhibits the production of KYNA, and the α2A-adrenoceptor agonist guanfacine regulates cAMP-calcium-potassium channel signaling in dlPFC and is also anti-inflammatory. Thus, these agents may be helpful in treating the cognitive symptoms of long COVID.
Source: Fesharaki Zadeh A, Arnsten AFT, Wang M. Scientific Rationale for the Treatment of Cognitive Deficits from Long COVID. Neurology International. 2023; 15(2):725-742. https://doi.org/10.3390/neurolint15020045 https://www.mdpi.com/2035-8377/15/2/45 (Full text)