Direct and indirect impact of SARS-CoV-2 on the brain

Abstract:

Although COVID-19 is mostly a pulmonary disease, it is now well accepted that it can cause a much broader spectrum of signs and symptoms and affect many other organs and tissue. From mild anosmia to severe ischemic stroke, the impact of SARS-CoV-2 on the central nervous system is still a great challenge to scientists and health care practitioners.

Besides the acute and severe neurological problems described, as encephalopathies, leptomeningitis, and stroke, after 2 years of pandemic, the chronic impact observed during long-COVID or the post-acute sequelae of COVID-19 (PASC) greatly intrigues scientists worldwide. Strikingly, even asymptomatic, and mild diseased patients may evolve with important neurological and psychiatric symptoms, as confusion, memory loss, cognitive decline, chronic fatigue, associated or not with anxiety and depression. Thus, the knowledge on the correlation between COVID-19 and the central nervous system is of great relevance.

In this sense, here we discuss some important mechanisms obtained from in vitro and in vivo investigation regarding how SARS-CoV-2 impacts the brain and its cells and function.

Source: Peron JPS. Direct and indirect impact of SARS-CoV-2 on the brain. Hum Genet. 2023 Apr 1:1–10. doi: 10.1007/s00439-023-02549-x. Epub ahead of print. PMID: 37004544; PMCID: PMC10066989. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10066989/ (Full text)

Case Study: COVID-19 Brain Fog or Auditory Processing Disorder?

A wide array of symptoms have been directly associated with COVID-19 following recovery, but they can also occur several weeks or months after the diagnosis. These include, but are not limited to, damage to the respiratory tract as well as decreased cognition and other brain functions. The nonmedical term used to describe these post-COVID-19 problems is “brain fog.”

The symptoms of brain fog are similar to mild cognitive impairment or, of interest to audiologists, an auditory processing disorder (APD). 2 COVID-19 has neurological consequences and affects specific areas of the brain, such as the cingulate cortex (i.e. emotions, memory, depression, and decision of action). 3 Brain fog is also associated with several symptoms related to hearing and communication, which can affect the accomplishment of routine daily tasks. Many of those can be mistaken for or coexist with APD symptoms. These include “difficulty attending or staying focused, difficulty concentrating, difficulty understanding or remembering instructions, language problems, short-term memory problems,” to mention a few. 2 However, what might appear as a brain fog case could be an undiagnosed or even a pre-existing APD issue. 2 Symptoms could include struggling to keep track of conversations, forgetfulness and memory issues, problems following directions, and several cognitive difficulties. 2

This report presents the case of a 31-year-old medical doctor who was diagnosed with COVID-19 in December 2020, and later identified with APD symptoms that are now commonly seen in post-COVID-19 brain fog patients. Auditory training following the Buffalo Model 4 resolved the patient’s chief complaints following 12 treatment sessions. This issue is one of many that could shed light on the great potential auditory training has in resolving brain fog complaints that overlap with what is commonly seen in APD patients, highlighting the concerns regarding COVID-19’s direct effects on auditory processing.

Source: Alexander, Angela Loucks AuD, MNZAS, CCC-A; DiSogra, Robert M. AuD; Abbas, Fatima BS; Braund, Stacey AuD, CCC-A; Spokes, Chelsea BSpHLSc, MClinAud. Case Study: COVID-19 Brain Fog or Auditory Processing Disorder?. The Hearing Journal 76(04):p 18,19,20,22,23,24, April 2023. | DOI: 10.1097/01.HJ.0000927332.17564.4e https://journals.lww.com/thehearingjournal/Fulltext/2023/04000/Case_Study__COVID_19_Brain_Fog_or_Auditory.2.aspx (Full text)

Chronic cough in post-COVID syndrome: Laryngeal electromyography findings in vagus nerve neuropathy

Abstract:

Background: Despite being a new entity, there is a large amount of information on the characteristics of SARS-CoV-2 infection and the symptoms of the acute phase; however, there are still many unknowns about the clinical features and pathophysiology of post-COVID syndrome. Refractory chronic cough is one of the most prevalent symptoms and carries both a medical problem and a social stigma. Many recent studies have highlighted the role of SARS-CoV-2 neurotropism, but no studies have demonstrated vagus nerve neuropathy as a cause of persistent chronic cough or other COVID-19 long-term effects.

Objective: The main objective was to assess the involvement of the vagus nerve neuropathy as a cause of chronic cough and other post-COVID syndrome symptoms.

Material and methods: This was a single-center observational study with prospective clinical data collected from 38 patients with chronic cough and post-COVID-19 syndrome. Clinical characteristics and laryngeal electromyographic findings were analyzed.

Results: Clinical data from 38 patients with chronic cough after 12 weeks of the acute phase of COVID-19 infection were analyzed. Of these patients, 81.6% suffered from other post-COVID conditions and, 73.6% reported fluctuating evolution of symptoms. Laryngeal electromyography (LEMG) of the thyroarytenoid (TA) muscles and cricothyroid (CT) muscles was pathological in 76.3% of the patients. Of the patients with abnormal LEMG, chronic denervation was the most frequent finding (82.8%), 10.3% presented acute denervation signs, and 6.9% presented myopathic pattern in LEMG.

Conclusions: LEMG studies suggest the existence of postviral vagus nerve neuropathy after SARS-CoV-2 infection that could explain chronic cough in post-COVID syndrome.

Source: García-Vicente P, Rodríguez-Valiente A, Górriz Gil C, Márquez Altemir R, Martínez-Pérez F, López-Pajaro LF, et al. (2023) Chronic cough in post-COVID syndrome: Laryngeal electromyography findings in vagus nerve neuropathy. PLoS ONE 18(3): e0283758. https://doi.org/10.1371/journal.pone.0283758 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0283758 (Full text)

Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem?

Abstract:

The coronavirus pandemic that began in 2019 continues. COVID-19 adversely affects human health not only in the acute, but also in the long-term period of the disease: in a large percentage of cases, health is not fully restored after long periods, requires medical intervention, and is often difficult to correct.

Researchers noted during the first wave of the pandemic in 2020 that about 10-20% of patients did not fully recover by three weeks from disease onset and the possible duration of the recovery period remains insufficiently clear, as do the reasons for differences in course during this period. Prolonged recovery after viral infection is not a feature exclusive to COVID-19, which does not facilitate the management of patients with post-COVID syndrome (PCS).

The mental health impact of COVID-19 is significant, with at least 30% of recovered patients likely to have symptoms of anxiety and/or depression after the acute phase has passed. Since the onset of COVID-19, there has been an increase in sleep disorders by 42%, with every third COVID-19 survivor reporting sleep complaints. In PCS, this condition is referred to as coronasomnia.

The success of therapy for this condition depends on identifying and correcting patients’ mental disorders, as anxiety and depression are often accompanied by sleep disorders this results in a bidirectional interaction between mental disorders and sleep quality. This article presents data on the anti-anxiety drugs Noofen and Adaptol, which help to correct the manifestations of PCS with sleep disorders.

Source: Kotova OV, Medvedev VE, Poluektov MG, Belyaev AA, Akarachkova ES. Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem? Neurosci Behav Physiol. 2023;53(1):16-20. doi: 10.1007/s11055-023-01385-w. Epub 2023 Mar 11. PMID: 36969358; PMCID: PMC10006556. https://link.springer.com/article/10.1007/s11055-023-01385-w (Full text available as PDF file)

 

Functional limitations in individuals with long COVID

Abstract:

Objectives: To examine the extent of long-term functional deficits experienced by individuals hospitalized for COVID-19. Specific objectives were to: 1. describe changes in perceived global health, mobility, participation in daily activities, and employment status from pre-COVID-19 to ≥2 months following infection; and 2. evaluate factors associated with change in function.

Design: We conducted a telephone survey (at least 2 months post infection).

Setting: Population-based study of adults living at home.

Participants: Adult residents in Laval, Quebec, who were discharged home post-hospitalization for COVID-19.

Interventions: Not applicable MAIN OUTCOME MEASURES: Participants responded to a standard questionnaire (Covid-19 Yorkshire Rehabilitation Screen) regarding persistent symptoms and limitations in daily functioning. We calculated the prevalence of changes in perceived global health, mobility, personal care, participation in daily activities, and employment and evaluated associated factors using bivariate analysis and multivariable logistic regression.

Results: Almost all participants (94%) were more fatigued and reported deterioration of their global health status (90%) at least three months after infection. The majority were more short of breath, and experienced pain and anxiety. The change in outcomes indicate a substantial reduction in those reporting ‘good’ health status, mobility, personal care, and daily activities, and less employment. Time since diagnosis was significantly associated with global health, mobility, and participation in daily activities.

Conclusion: This population-based study suggests that individuals hospitalized for COVID-19 infection have symptoms that impact daily functional activities many months after infection. It is imperative that the impact of infection is better understood so that those affected long-term can receive the needed services.

Source: Mazer B, Feldman DE. Functional limitations in individuals with long COVID. Arch Phys Med Rehabil. 2023 Mar 24:S0003-9993(23)00162-4. doi: 10.1016/j.apmr.2023.03.004. Epub ahead of print. PMID: 36966957; PMCID: PMC10036292. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10036292/ (Full text)

A prospective cohort study assessing the relationship between long-COVID symptom incidence in COVID-19 patients and COVID-19 vaccination

Abstract:

Current studies about the long-term effects of COVID-19 show a wide range of symptoms. This prospective cohort study aimed to find the incidence of long-COVID symptoms and the associated risk factors.

We followed 669 confirmed COVID-19 patients. Sociodemographic and clinical data were extracted from medical records and collected via semi-structured telephone interviews on days 10, 30, 60, and 90. The incidence of long-COVID symptoms was 41.6% (95% CI 37.8-45.4%). Females [aOR = 1.5 (95% CI 1.1-2.3)], the elderly [aOR = 4.9 (95% CI 2.0-11.3)], and those who required hospitalization [aOR = 5.0 (95% CI 1.3-3.7)] were at a higher risk of developing long-COVID. Patients with dyspnea at day 10 [aOR: 2.4 (95% CI 1.6-3.7] and fatigue at day 60 [aOR: 3.1 (95% CI 1.5-6.3] were also at risk. While non-vaccinated patients were almost seven times more likely to report long-COVID symptoms than vaccinated patients [aOR: 6.9 (95% CI 4.2-11.3)].

In conclusion, long-COVID was common among COVID-19 patients, with higher rates among females, older age groups, hospitalized patients, and those with dyspnea and fatigue, while vaccination provided protection. Interventions should educate health professionals, raise general public awareness about the risks and consequences of Long COVID, and the value of vaccination.

Source: Abu Hamdh B, Nazzal Z. A prospective cohort study assessing the relationship between long-COVID symptom incidence in COVID-19 patients and COVID-19 vaccination. Sci Rep. 2023 Mar 25;13(1):4896. doi: 10.1038/s41598-023-30583-2. PMID: 36966161; PMCID: PMC10039348. https://www.nature.com/articles/s41598-023-30583-2 (Full text)

Treatment of Long COVID symptoms with triple anticoagulant therapy

Abstract:

Background: Fibrin(ogen) amyloid microclots and platelet hyperactivation are key pathological findings in patients with acute COVID-19 infection and also in those with Long COVID/Post-Acute Sequelae of COVID-19 (PASC). These pathologies may represent a suitable target for pharmacological treatment of Long COVID.

Methods: Here we report on the symptoms displayed by a cohort of 91 South African Long COVID patients at baseline and after a clinician-initiated anticoagulant regime was completed. For laboratory analysis, patients provided a blood sample before and after treatment. Fibrinaloid microclot presence was studied by adding thioflavin T to platelet poor plasma (PPP), whilst platelet hyperactivation was studied using two platelet markers- PAC1 and CD62P (P-selectin). The anticoagulant regime included dual antiplatelet therapy (DAPT- Clopidogrel 75mg + Aspirin 75mg) once a day, and a direct oral anticoagulant (DOAC- Apixaban) 5mg twice a day. A proton pump inhibitor (PPI) pantoprazole 40 mg/day was also prescribed for gastric protection. Each of the treated cases reported their main Long COVID symptoms, and whether their symptoms resolved following treatment or not.

Results: In our cohort a most participants did not report any comorbidities before acute COVID-19 infection. Hypertension and dyslipidaemia were the commonest underlying illnesses, whilst the most commonly reported Long COVID symptoms included fatigue, cognitive dysfunction, shortness of breath, and joint and muscle pains. Following completion of treatment, each of the different symptoms resolved in the majority of patients. This was also reflected in the laboratory analysis, where a decrease in the severity of fibrin amyloid microclotting and the degree of platelet pathology was noted. No serious adverse bleeding events were reported.

Conclusions: Fibrin amyloid microclots, platelet hyperactivation/ aggregation, and  widespread endothelialitis inhibit the transport of oxygen at a capillary/cellular level. This provides a ready explanation for the symptoms of Long COVID. By normalizing the failed clotting physiology and reversal of the endothelialitis, triple anticoagulant therapy represents a promising treatment option that appears to be highly efficacious, and warrants controlled clinical studies. We caution that such a regime must only be followed under expert medical supervision in view of the risk of  bleeding.

Source: Gert J Laubscher, M Asad Khan, Chantelle Venter, Etheresia Pretorius et al. Treatment of Long COVID symptoms with triple anticoagulant therapy, 21 March 2023, PREPRINT (Version 1) available at Research Square https://doi.org/10.21203/rs.3.rs-2697680/v1 (Full text)

The health impact of long COVID: a cross-sectional examination of health-related quality of life, disability, and health status among individuals with self-reported post-acute sequelae of SARS CoV-2 infection at various points of recovery

Abstract:

Objective: The novel Coronavirus (COVID-19) has continued to present a significant burden to global public health efforts. The purpose of this study was to estimate the health-related quality of life, disability, and health status of individuals with self-reported long COVID at various lengths of recovery.

Methods: We conducted a cross-sectional online survey of individuals with self-reported long COVID. Participants were asked to complete the five-item EuroQOL EQ-5D-5L and EQ visual analog scale, the 12-item World Health Organization Disability Assessment Schedule (WHODAS) 2.0 and the 10-item Patient Reported Outcome Measurement Information System (PROMIS) Global Health v1.2 short form. Descriptive and inferential statistics were used to characterize the responses and differences across groups.

Results: Eighty-two participants from 13 countries completed the EQ-5D-5L, 73 completed the WHODAS 2.0 and 80 participants completed the PROMIS. The mean EQ-5D-5L utility score was 0.51. The mean WHODAS score was 49.0. In the previous 30 days, participants reported their symptoms affected them for a mean of 24 days, they were totally unable to carry out usual activities for 15 days, and they cut back or reduced activities for 26 days. The mean PROMIS physical health and mental health scores were 10.7 and 8.6, respectively, corresponding to below-average health. No significant differences were detected across time or according to severity of acute infection.

Conclusions: Long COVID presents a significant chronic health burden to adults in the US and abroad. This health burden may persist for many months post-acute infection.

Source: Tak CR. The health impact of long COVID: a cross-sectional examination of health-related quality of life, disability, and health status among individuals with self-reported post-acute sequelae of SARS CoV-2 infection at various points of recovery. J Patient Rep Outcomes. 2023 Mar 21;7(1):31. doi: 10.1186/s41687-023-00572-0. PMID: 36943643; PMCID: PMC10029785. https://jpro.springeropen.com/articles/10.1186/s41687-023-00572-0 (Full text)

Long Covid: clues about causes

Abstract:(Full text

Many patients report persistent symptoms after resolution of acute COVID-19, regardless of SARS-CoV-2 variant and even if the initial illness is mild [1, 2]. A multitude of symptoms have been described under the umbrella term ‘Long COVID’, otherwise known as ‘post-COVID syndrome’ or ‘post-acute sequelae of SARS-CoV-2 (PASC)’; for simplicity we will use the term Long COVID.

Symptoms are diverse but include breathlessness, fatigue and brain fog, reported to affect up to 69% of cases [3]. Long COVID can be debilitating, 45.2% of patients requiring a reduced work schedule [4]. The WHO estimates that 17 million people in Europe have experienced Long COVID during the first two years of the pandemic [5]. SARS-CoV-2 variants continue to circulate and the risk of post-acute complications remains; a recent study of 56 003 UK patients found that even after Omicron infection, 4.5% suffered persistent symptoms [6].

It is therefore likely that Long COVID will provide a substantial medical and economic burden for the foreseeable future. There is an urgent need to understand mechanisms of disease and develop effective treatments based on this understanding.

Source: Liew F, Efstathiou C, Openshaw PJ. Long Covid: clues about causes. Eur Respir J. 2023 Mar 23:2300409. doi: 10.1183/13993003.00409-2023. Epub ahead of print. PMID: 36958743; PMCID: PMC10040855. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10040855/ (Full text)

What is really ‘Long COVID’?

Abstract:

The previous acute respiratory diseases caused by viruses originating from China or the middle east (e.g., SARS, MERS) remained fast developing short diseases without major sequalae or any long-lasting complications. The new COVID-19, on the other hand, not only that it rapidly spread over the world, but some patients never fully recovered or even if they did, a few weeks later started to complain not only of shortness of breath, if any, but general weakness, muscle pains and ‘brain fog’, i.e., fuzzy memories. Thus, these signs and symptoms were eventually labelled ‘long COVID’, for which the most widely used definition is ‘new signs and symptoms occurring 4-8 weeks after recovering from acute stage of COVID-19’.

The other most frequent manifestations associated with long COVID include headache, loss of memory, smell and of hair, nausea, and vomiting. Thus, long COVID is not a simple disease, but complex disorder of several organ systems malfunctioning; hence, it is probably more appropriate to call this a syndrome.

The pathogenesis of long COVID syndrome is poorly understood, but initial and persistent vascular endothelial injury that often triggers the formation of microthrombi that if dislodged as emboli, damage several organs, especially in the brain, heart and kidney, by creating microinfarcts.

The other major contributory mechanistic factor is the persistent cytokine storm that may last longer in long COVID patients than in others, probably triggered by aggregates of SARS-Co-2 discovered recently in the adrenal cortex, kidney and brain.

The prevalence of long COVID is relatively high, e.g., initially varied 3-30%, and recent data indicate that 2.5% of UK population suffers from this syndrome, while in the US 14.7% of acute COVID-19 patients continued to have symptoms longer than 2 months. Thus, the long COVID syndrome deserves to be further investigated, both from clinical and basic research perspectives.

Source: Szabo S, Zayachkivska O, Hussain A, Muller V. What is really ‘Long COVID’? Inflammopharmacology. 2023 Mar 25:1–7. doi: 10.1007/s10787-023-01194-0. Epub ahead of print. PMID: 36964860; PMCID: PMC10039447. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10039447/ (Full text)