Tag: long covid neurology

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)

Brain disorders: Impact of mild SARS-CoV-2 may shrink several parts of the brain

Abstract:

Coronavirus (COVID-19) is a highly infectious respiratory infection discovered in Wuhan, China, in December 2019. As a result of the pandemic, several individuals have experienced life-threatening diseases, the loss of loved ones, lockdowns, isolation, an increase in unemployment, and household conflict. Moreover, COVID-19 may cause direct brain injury via encephalopathy. The long-term impacts of this virus on mental health and brain function need to be analysed by researchers in the coming years.

This article aims to describe the prolonged neurological clinical consequences related to brain changes in people with mild COVID-19 infection. When compared to a control group, people those who tested positive for COVID-19 had more brain shrinkage, grey matter shrinkage, and tissue damage. The damage occurs predominantly in areas of the brain that are associated with odour, ambiguity, strokes, reduced attention, headaches, sensory abnormalities, depression, and mental abilities for few months after the first infection. Therefore, in patients after a severe clinical condition of COVID-19, a deepening of persistent neurological signs is necessary.

Source: Kumar PR, Shilpa B, Jha RK. Brain Disorders: Impact of Mild SARS-CoV-2 May Shrink Several Parts of the Brain. Neurosci Biobehav Rev. 2023 Mar 31;149:105150. doi: 10.1016/j.neubiorev.2023.105150. Epub ahead of print. PMID: 37004892; PMCID: PMC10063523. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10063523/ (Full text)

Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

Abstract:

We measured brain injury markers, inflammatory mediators, and autoantibodies in 203 participants with COVID-19; 111 provided acute sera (1-11 days post admission) and 56 with COVID-19-associated neurological diagnoses provided subacute/convalescent sera (6-76 weeks post-admission).

Compared to 60 controls, brain injury biomarkers (Tau, GFAP, NfL, UCH-L1) were increased in acute sera, significantly more so for NfL and UCH-L1, in patients with altered consciousness. Tau and NfL remained elevated in convalescent sera, particularly following cerebrovascular and neuroinflammatory disorders. Acutely, inflammatory mediators (including IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) were higher in participants with altered consciousness, and correlated with brain injury biomarker levels. Inflammatory mediators were lower than acute levels in convalescent sera, but levels of CCL2, CCL7, IL-1RA, IL-2Rα, M-CSF, SCF, IL-16 and IL-18 in individual participants correlated with Tau levels even at this late time point.

When compared to acute COVID-19 patients with a normal GCS, network analysis showed significantly altered immune responses in patients with acute alteration of consciousness, and in convalescent patients who had suffered an acute neurological complication. The frequency and range of autoantibodies did not associate with neurological disorders. However, autoantibodies against specific antigens were more frequent in patients with altered consciousness in the acute phase (including MYL7, UCH-L1, GRIN3B, and DDR2), and in patients with neurological complications in the convalescent phase (including MYL7, GNRHR, and HLA antigens).

In a novel low-inoculum mouse model of SARS-CoV-2, while viral replication was only consistently seen in mouse lungs, inflammatory responses were seen in both brain and lungs, with significant increases in CCL4, IFNγ, IL-17A, and microglial reactivity in the brain. Neurological injury is common in the acute phase and persists late after COVID-19, and may be driven by a para-infectious process involving a dysregulated host response.

Source: Benedict D. Michael, Cordelia Dunai, Edward J. Needham, Kukatharmini Tharmaratnam, Robyn Williams, Yun Huang, Sarah A. Boardman, Jordan Clark, Parul Sharma, Krishanthi Subramaniam, Greta K. Wood, Ceryce Collie, Richard Digby, Alexander Ren, Emma Norton, Maya Leibowitz, Soraya Ebrahimi, Andrew Fower, Hannah Fox, Esteban Tato, Mark Ellul, Geraint Sunderland, Marie Held, Claire Hetherington, Franklyn Nkongho, Alish Palmos, Alexander Grundmann, James P. Stewart, Michael Griffiths, Tom Solomon, Gerome Breen, Alasdair Coles, Jonathan Cavanagh, Sarosh R. Irani, Angela Vincent, Leonie Taams, David K. Menon. Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses. medRxiv 2023.04.03.23287902; doi: https://doi.org/10.1101/2023.04.03.23287902 (Full text available as PDF file)

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)

Neurocognitive and psychiatric symptoms following infection with COVID-19: Evidence from laboratory and population studies

Abstract:

Objective: The objective of the current investigation was to examine associations between symptomatic COVID-19 history, neurocognitive function, and psychiatric symptoms using cognitive task performance, functional brain imaging, and a prospective population survey.

Methods: Study 1 was a laboratory study conducted between 3 May 2022 and 16 Nov 2022 involving 120 fully vaccinated community dwelling adults between 18 and 84 years of age (Mage = 31.96 (SD = 20.71), 63.3% female). In this cross-sectional study we examined the association between symptomatic COVID-19 infection history and performance on three computer tasks assessing cognitive function (Flanker interference, delay discounting and simple reaction time) and measured oxygen saturation within the prefrontal cortex using functional near infrared spectroscopy (fNIRS). Study 2 was a 2-wave population survey undertaken between 28 September 2021 and 21 March 2022, examining the prospective relationship between symptomatic COVID-19 and self-reported symptoms of cognitive dysfunction, depressive symptoms, anxiety symptoms, and agitation at 6-month follow up. The sample (N = 2,002, M age = 37.0, SD = 10.4; 60.8% female) was collected using a quota process to ensure equal numbers of vaccinated and unvaccinated individuals. Structural equation modelling with latent variables was performed on the population-level data, evaluating the fit of the proposed mediational model of symptomatic COVID-19 to psychiatric symptoms through cognitive dysfunction.

Results: Findings from Study 1 revealed significant effects of symptomatic COVID-19 history on Flanker interference and delay discounting. Effects on flanker performance were significantly stronger among older adult women (effect: 9.603, SE = 4.452, t = 2.157, p = .033), and were accompanied by task-related changes cerebral oxygenation at the right superior frontal gyrus (F (1, 143.1) = 4.729, p = .031). Additionally, those with a symptomatic COVID-19 infection history showed evidence of amplified delay discounting (coefficient = 0.4554, SE = 0.2208, t = 2.0629, p = .041). In Study 2, baseline symptomatic COVID-19 history was associated with self-reported cognitive dysfunction and a latent variable reflecting psychiatric symptoms of anxiety, depression and agitation at follow-up. Mediational analyses revealed evidence of cognitive mediation of clinically significant psychiatric outcomes: depression (indirect effect = 0.077, SE = 0.026, p = .003) and generalized anxiety (indirect effect = 0.060, SE = 0.021, p = .004).

Conclusions: Converging findings from laboratory and population survey data support the conclusion that symptomatic COVID-19 infection is associated with task-related, functional imaging and self-reported indices of cognitive dysfunction as well as psychiatric symptoms. In some cases, these findings appear to be more amplified among women than men, and among older women than younger.

Source: Hall PA, Ayaz H, Meng G, Hudson A, Sakib MN, Quah ACK, Agar TK, Lee JA, Boudreau C, Fong GT. Neurocognitive and psychiatric symptoms following infection with COVID-19: Evidence from laboratory and population studies. Brain Behav Immun Health. 2023 Mar;28:100595. doi: 10.1016/j.bbih.2023.100595. Epub 2023 Jan 24. PMID: 36713476; PMCID: PMC9870612. https://www.sciencedirect.com/science/article/pii/S2666354623000091?via%3Dihub (Full study)

The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures

Highlights:

  • None of the SARS-CoV-2 original, delta, or omicron strains can infect neurons.
  • The SARS-CoV-2 original, delta, and omicron strains can infect microglia.
  • The CNS cells differentiated from hiPSCs are useful to investigate the infectivity of the virus.

Abstract:

COVID-19 causes neurological damage, systemic inflammation, and immune cell abnormalities. COVID-19-induced neurological impairment may be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which directly infects cells of the central nervous system (CNS) and exerts toxic effects. Furthermore, SARS-CoV-2 mutations occur constantly, and it is not well understood how the infectivity of the virus to cells of the CNS changes as the virus mutates.

Few studies have examined whether the infectivity of cells of CNS – neural stem/progenitor cells (NS/PCs), neurons, astrocytes, and microglia – varies among SARS-CoV-2 mutant strains. In this study, therefore, we investigated whether SARS-CoV-2 mutations increase infectivity to CNS cells, including microglia.

Since it was essential to demonstrate the infectivity of the virus to CNS cells in vitro using human cells, we generated cortical neurons, astrocytes, and microglia from human induced pluripotent stem cells (hiPSCs). We added pseudotyped lentiviruses of SARS-CoV-2 to each type of cells, and then we examined their infectivity. We prepared three pseudotyped lentiviruses expressing the S protein of the original strain (the first SARS-CoV-2 discovered in the world), the Delta variant, and the Omicron variant on their envelopes and analyzed differences of their ability to infect CNS cells. We also generated brain organoids and investigated the infectivity of each virus.

The viruses did not infect cortical neurons, astrocytes, or NS/PCs, but microglia were infected by the original, Delta, and Omicron pseudotyped viruses. In addition, DPP4 and CD147, potential core receptors of SARS-CoV-2, were highly expressed in the infected microglia, while DPP4 expression was deficient in cortical neurons, astrocytes, and NS/PCs.

Our results suggest that DPP4, which is also a receptor for Middle East respiratory syndrome-coronavirus (MERS-CoV), may play an essential role in the CNS. Our study is applicable to the validation of the infectivity of viruses that cause various infectious diseases in CNS cells, which are difficult to sample from humans.

Source: Kase Y, Sonn I, Goto M, Murakami R, Sato T, Okano H. The original strain of SARS-CoV-2, the Delta variant, and the Omicron variant infect microglia efficiently, in contrast to their inability to infect neurons: Analysis using 2D and 3D cultures. Exp Neurol. 2023 Mar 11;363:114379. doi: 10.1016/j.expneurol.2023.114379. Epub ahead of print. PMID: 36914084; PMCID: PMC10008041. https://www.sciencedirect.com/science/article/pii/S0014488623000638?via%3Dihub (Full text)

Potential Prion Involvement in Long COVID-19 Neuropathology, Including Behavior

Abstract:

Prion is a term used to describe a protein infectious particle responsible for several neurodegenerative diseases in mammals, e.g., Creutzfeldt-Jakob disease. The novelty is that it is protein based infectious agent not involving a nucleic acid genome as found in viruses and bacteria.

Prion disorders exhibit, in part, incubation periods, neuronal loss, and induce abnormal folding of specific normal cellular proteins due to enhancing reactive oxygen species associated with mitochondria energy metabolism. These agents may also induce memory, personality and movement abnormalities as well as depression, confusion and disorientation.

Interestingly, some of these behavioral changes also occur in COVID-19 and mechanistically include mitochondrial damage caused by SARS-CoV-2 and subsequent production of reactive oxygen species. Taken together, we surmise, in part, long COVID may involve the induction of spontaneous prion emergence, especially in individuals susceptible to its origin may thus explain some of its manisfestions post-acute viral infection.

Source: Stefano GB, Büttiker P, Weissenberger S, Anders M, Raboch J, Ptacek R, Kream RM. Potential Prion Involvement in Long COVID-19 Neuropathology, Including Behavior. Cell Mol Neurobiol. 2023 Mar 28:1–6. doi: 10.1007/s10571-023-01342-8. Epub ahead of print. PMID: 36977809; PMCID: PMC10047479. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10047479/ (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)

 

Neurologic manifestations of long COVID differ based on acute COVID-19 severity

Abstract:

Objective: To characterize neurologic manifestations in post-hospitalization Neuro-PASC (PNP) and non-hospitalized Neuro-PASC (NNP) patients.

Methods: Prospective study of the first 100 consecutive PNP and 500 NNP patients evaluated at a Neuro-COVID-19 clinic between 5/2020 and 8/2021.

Results: PNP were older than NNP patients (mean 53.9 vs 44.9 y; p < 0.0001) with a higher prevalence of pre-existing comorbidities. An average 6.8 months from onset, the main neurologic symptoms were “brain fog” (81.2%), headache (70.3%), and dizziness (49.5%) with only anosmia, dysgeusia and myalgias being more frequent in the NNP compared to the PNP group (59 vs 39%, 57.6 vs 39% and 50.4 vs 33%, all p < 0.003). Moreover, 85.8% of patients experienced fatigue. PNP more frequently had an abnormal neurologic exam than NNP patients (62.2 vs 37%, p < 0.0001). Both groups had impaired quality of life in cognitive, fatigue, sleep, anxiety, and depression domains. PNP patients performed worse on processing speed, attention, and working memory tasks than NNP patients (T-score 41.5 vs 55, 42.5 vs 47 and 45.5 vs 49, all p < 0.001) and a US normative population. NNP patients had lower results in attention task only. Subjective impression of cognitive ability correlated with cognitive test results in NNP but not in PNP patients.

Interpretation: PNP and NNP patients both experience persistent neurologic symptoms affecting their quality of life. However, they harbor significant differences in demographics, comorbidities, neurologic symptoms and findings, as well as pattern of cognitive dysfunction. Such differences suggest distinct etiologies of Neuro-PASC in these populations warranting targeted interventions.

Source: Perez Giraldo GS, Ali ST, Kang AK, Patel TR, Budhiraja S, Gaelen JI, Lank GK, Clark JR, Mukherjee S, Singer T, Venkatesh A, Orban ZS, Lim PH, Jimenez M, Miller J, Taylor C, Szymanski AL, Scarpelli J, Graham EL, Balabanov RD, Barcelo BE, Cahan JG, Ruckman K, Shepard AG, Slutzky MW, LaFaver K, Kumthekar PU, Shetty NK, Carroll KS, Ho SU, Lukas RV, Batra A, Liotta EM, Koralnik IJ. Neurologic manifestations of long COVID differ based on acute COVID-19 severity. Ann Neurol. 2023 Mar 26. doi: 10.1002/ana.26649. Epub ahead of print. PMID: 36966460. https://onlinelibrary.wiley.com/doi/abs/10.1002/ana.26649 (Full text available as PDF file)