Tag: long covid neurology

A Cross-Sectional Study of Symptom Prevalence, Frequency, Severity, and Impact of Long-COVID in Scotland: Part II

Abstract:

Background: There has been some effort to map the prevalence, frequency, and severity of symptoms of long-COVID at local and national levels. However, what is frequently absent from such accounts is details of the impact the disease and its symptoms have had on those living with the condition. In this manuscript, we present details of impact to work, caring, and mental health gathered using a cross-sectional survey.

Methods: Data were collected using an online survey which was available from 21st April 2022 to 5th August 2022. Included participants had either self-diagnosed or confirmed long-COVID, were living in Scotland, and were ≥18 years old. Hospitalisation during initial COVID-19 infection was an exclusion criterion. Participants were asked to report on the impact of their illness on everyday activities such as working, studying, or caring. They also completed an assessment of their current mood.

Results: People with long-COVID were often severely impacted in their ability to work and study. Severe impact on work and study were predicted by more severe and more frequent fatigue, more severe pain, and more severe cognitive impairment. Respondents’ ability to care for child dependants was also associated with more severe and more frequent fatigue, as well as more severe cognitive impairments. More severe pain associated with greater impact on adult care. Negative mood correlated most strongly with frequency and severity of neurological symptoms, including lack of attention, loss of smell, impaired sense of smell, loss of taste, impaired sense of taste, and loss of appetite.

Conclusions: Long-COVID has a significant impact on ability to work, study, and care for dependants. The severity of this impact is associated with specific symptom burden, including fatigue, pain, and cognitive impairment.

Source: Mclaughlin M, Cerexhe L, Macdonald E, Ingram J, Sanal-Hayes NEM, Hayes LD, Meach R, Carless D, Sculthorpe N. A Cross-Sectional Study of Symptom Prevalence, Frequency, Severity, and Impact of Long-COVID in Scotland: Part II. Am J Med. 2023 Jul 19:S0002-9343(23)00461-8. doi: 10.1016/j.amjmed.2023.07.009. Epub ahead of print. PMID: 37478960. https://www.amjmed.com/article/S0002-9343(23)00461-8/fulltext (Full text)

Cortical thickness alterations and systemic inflammation define long-COVID patients with cognitive impairment

Abstract:

As the heterogeneity of symptoms is increasingly recognized among long-COVID patients, it appears highly relevant to study potential pathophysiological differences along the different subtypes. Preliminary evidence suggests distinct alterations in brain structure and systemic inflammatory patterns in specific groups of long-COVID patients.

To this end, we analyzed differences in cortical thickness and peripheral immune signature between clinical subgroups based on 3T-MRI scans and signature inflammatory markers in n=120 participants comprising healthy never-infected controls, healthy COVID-19 survivors, and subgroups of long-COVID patients with and without cognitive impairment according to screening with Montreal Cognitive Assessment.

Whole-brain comparison of cortical thickness between the 4 groups was conducted by surface-based morphometry. We identified distinct cortical areas showing a progressive increase in cortical thickness across different groups, starting from healthy individuals who had never been infected with COVID-19, followed by healthy COVID-19 survivors, long-COVID patients without cognitive deficits (MoCA ≥ 26), and finally, long-COVID patients exhibiting significant cognitive deficits (MoCA < 26). These findings highlight the continuum of cortical thickness alterations associated with COVID-19, with more pronounced changes observed in individuals experiencing cognitive impairment (p<0.05, FWE-corrected).

Affected cortical regions covered prefrontal and temporal gyri, insula, posterior cingulate, parahippocampal gyrus, and parietal areas. Additionally, we discovered a distinct immunophenotype, with elevated levels of IL-10, IFNg, and sTREM2 in long-COVID patients, especially in the group suffering from cognitive impairment.

We demonstrate lingering cortical and immunological alterations in healthy and impaired subgroups of COVID-19 survivors. This implies a complex underlying pathomechanism in long-COVID and emphasizes the necessity to investigate the whole spectrum of post-COVID biology to determine targeted treatment strategies targeting specific sub-groups.

Source: Bianca Besteher, Tonia Rocktaeschel, Alejandra Patricia Garza, Marlene Machnik, Johanna Ballez, Dario Lucas Helbing, Katrhin Finke, Philipp Reuken, Daniel Guellmar, Christian Gaser, Martin Walter, Nils Opel, Ildiko Rita Dunay. Cortical thickness alterations and systemic inflammation define long-COVID patients with cognitive impairment. medRxiv 2023.07.21.23292988; doi: https://doi.org/10.1101/2023.07.21.23292988 https://www.medrxiv.org/content/10.1101/2023.07.21.23292988v1v (Full text available as PDF file)

Carotid body dysregulation contributes to the enigma of long COVID

Abstract:

The symptoms of long COVID, which include fatigue, breathlessness, dysregulated breathing, and exercise intolerance, have unknown mechanisms. These symptoms are also observed in heart failure and are partially driven by increased sensitivity of the carotid chemoreflex. As the carotid body has an abundance of ACE2 (the cell entry mechanism for SARS-CoV-2), we investigated whether carotid chemoreflex sensitivity was elevated in participants with long COVID. During cardiopulmonary exercise testing, the VE/VCO2 slope (a measure of breathing efficiency) was higher in the long COVID group than in the controls, indicating excessive hyperventilation.

The hypoxic ventilatory response, which measures carotid chemoreflex sensitivity, was increased in long COVID participants and correlated with the VE/VCO2 slope, suggesting that excessive hyperventilation may be related to carotid body hypersensitivity. Therefore, the carotid chemoreflex is sensitized in long COVID and may explain dysregulated breathing and exercise intolerance in these participants. Tempering carotid body excitability may be a viable treatment option for long COVID patients.

Source: Ahmed El-Medany, Zoe H Adams, Hazel C Blythe, Katrina A Hope, Adrian H Kendrick, Ana Paula Abdala Sheikh, Julian FR Paton, Angus K Nightingale, Emma C Hart. Carotid body dysregulation contributes to the enigma of long COVID. medRxiv 2023.05.25.23290513; doi: https://doi.org/10.1101/2023.05.25.23290513 https://www.medrxiv.org/content/10.1101/2023.05.25.23290513v1.full-text (Full text)

Long COVID, the Brain, Nerves, and Cognitive Function

Abstract:

SARS-CoV-2, a single-stranded RNA coronavirus, causes an illness known as coronavirus disease 2019 (COVID-19). Long-term complications are an increasing issue in patients who have been infected with COVID-19 and may be a result of viral-associated systemic and central nervous system inflammation or may arise from a virus-induced hypercoagulable state. COVID-19 may incite changes in brain function with a wide range of lingering symptoms.
Patients often experience fatigue and may note brain fog, sensorimotor symptoms, and sleep disturbances. Prolonged neurological and neuropsychiatric symptoms are prevalent and can interfere substantially in everyday life, leading to a massive public health concern. The mechanistic pathways by which SARS-CoV-2 infection causes neurological sequelae are an important subject of ongoing research. Inflammation- induced blood-brain barrier permeability or viral neuro-invasion and direct nerve damage may be involved. Though the mechanisms are uncertain, the resulting symptoms have been documented from numerous patient reports and studies.
This review examines the constellation and spectrum of nervous system symptoms seen in long COVID and incorporates information on the prevalence of these symptoms, contributing factors, and typical course. Although treatment options are generally lacking, potential therapeutic approaches for alleviating symptoms and improving quality of life are explored.
Source: Reiss AB, Greene C, Dayaramani C, Rauchman SH, Stecker MM, De Leon J, Pinkhasov A. Long COVID, the Brain, Nerves, and Cognitive Function. Neurology International. 2023; 15(3):821-841. https://doi.org/10.3390/neurolint15030052 https://www.mdpi.com/2035-8377/15/3/52 (Full text)

Altered brain connectivity in Long Covid during cognitive exertion: a pilot study

Abstract:

Introduction: Debilitating Long-Covid symptoms occur frequently after SARS-COVID-19 infection.

Methods: Functional MRI was acquired in 10 Long Covid (LCov) and 13 healthy controls (HC) with a 7 Tesla scanner during a cognitive (Stroop color-word) task. BOLD time series were computed for 7 salience and 4 default-mode network hubs, 2 hippocampus and 7 brainstem regions (ROIs). Connectivity was characterized by the correlation coefficient between each pair of ROI BOLD time series. We tested for HC versus LCov differences in connectivity between each pair of the 20 regions (ROI-to-ROI) and between each ROI and the rest of the brain (ROI-to-voxel). For LCov, we also performed regressions of ROI-to-ROI connectivity with clinical scores.

Results: Two ROI-to-ROI connectivities differed between HC and LCov. Both involved the brainstem rostral medulla, one connection to the midbrain, another to a DM network hub. Both were stronger in LCov than HC. ROI-to-voxel analysis detected multiple other regions where LCov connectivity differed from HC located in all major lobes. Most, but not all connections, were weaker in LCov than HC. LCov, but not HC connectivity, was correlated with clinical scores for disability and autonomic function and involved brainstem ROI.

Discussion: Multiple connectivity differences and clinical correlations involved brainstem ROIs. Stronger connectivity in LCov between the medulla and midbrain may reflect a compensatory response. This brainstem circuit regulates cortical arousal, autonomic function and the sleep-wake cycle. In contrast, this circuit exhibited weaker connectivity in ME/CFS. LCov connectivity regressions with disability and autonomic scores were consistent with altered brainstem connectivity in LCov.

Source: Barnden L, Thapaliya K, Eaton-Fitch N, Barth M, Marshall-Gradisnik S. Altered brain connectivity in Long Covid during cognitive exertion: a pilot study. Front Neurosci. 2023 Jun 22;17:1182607. doi: 10.3389/fnins.2023.1182607. PMID: 37425014; PMCID: PMC10323677. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10323677/ (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)

SARS-CoV-2 infection and viral fusogens cause neuronal and glial fusion that compromises neuronal activity

Abstract:

Numerous viruses use specialized surface molecules called fusogens to enter host cells. Many of these viruses, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can infect the brain and are associated with severe neurological symptoms through poorly understood mechanisms.

We show that SARS-CoV-2 infection induces fusion between neurons and between neurons and glia in mouse and human brain organoids. We reveal that this is caused by the viral fusogen, as it is fully mimicked by the expression of the SARS-CoV-2 spike (S) protein or the unrelated fusogen p15 from the baboon orthoreovirus.

We demonstrate that neuronal fusion is a progressive event, leads to the formation of multicellular syncytia, and causes the spread of large molecules and organelles. Last, using Ca2+ imaging, we show that fusion severely compromises neuronal activity. These results provide mechanistic insights into how SARS-CoV-2 and other viruses affect the nervous system, alter its function, and cause neuropathology.

Source: Ramón Martínez-Mármol et al, SARS-CoV-2 infection and viral fusogens cause neuronal and glial fusion that compromises neuronal activity., Science Advances (2023). DOI: 10.1126/sciadv.adg2248. www.science.org/doi/10.1126/sciadv.adg2248 (Full text)

Do Pre-existing Sleep Disorders Worsen Long COVID Fatigue and Brain Fog?

Abstract:

Introduction: Long COVID is common after COVID-19 infection and leads to functional limitations with most reporting substantial symptom burden from fatigue. Symptoms in sleep disorders are attributed to inflammatory dysregulation and may predispose to fatigue expression. We hypothesize prior diagnoses of sleep disorders are associated with severity of long COVID fatigue.
Methods: A retrospective EMR review was performed of 210 consecutive adult patients (9/2021 to 2/2022) referred at least 3 months after COVID-19 infection seen in a new community-based long COVID clinic. The intake process collected demographics, past medical history, functional questionnaires, and symptom checklists. Primary outcome was Fatigue Severity Scale (FSS) score. Sleep disorders were evaluated as a composite of self-reported insomnia, sleep disordered breathing, and restless legs syndrome as well as subset analyses of each disorder. Secondary outcome was physical functioning measured by ECOG performance scale. Linear analyses were used for FSS and ECOG analyses. Adjustors included age, sex, body mass index (BMI), and whether patient had COVID-19 hospitalization.
Results: Cohort was female (66.2%), aged 51.6±SD14.4 yrs, BMI 29.8 [IQR 26.2, 37.7]). Prior chronic insomnia was present in 9%, sleep disordered breathing in 23%, and RLS in 4%; the pooled history of sleep disorders was 30%. Fatigue was reported in 76% with mean FSS score of 5.44 [interquartile range, IQR: 4.11,6.44]; 48% reported brain fog. The interval between acute COVID infection and clinic evaluation was 10.4±5.34 months and had no association to FSS severity (r = 0.07, p = 0.30). Sleep disorders in aggregate, insomnia, and restless legs syndrome had no associations with fatigue or functional status. Sleep disordered breathing had an association to fatigue in unadjusted (β = 0.68, 95% confidence interval, [CI]:0.13,1.24), but not adjusted models (β = 0.53, 95%CI: -0.06,1.13). Sleep disorders both in aggregate and evaluated individually had no associations to brain fog.
Conclusion: A prior history of sleep disorders contributed little to post-COVID fatigue reported in those presenting to a community-based Long COVID clinic.

Source: Isabelle Carter and others, 0967 Do Pre-existing Sleep Disorders Worsen Long COVID Fatigue and Brain Fog?, Sleep, Volume 46, Issue Supplement_1, May 2023, Pages A426–A427, https://doi.org/10.1093/sleep/zsad077.0967 (Full text is available as PDF file)

Diagnostic value of 24-h ECG recording in Long COVID patients with postural orthostatic tachycardia syndrome

Abstract:

Background: Cardiovascular autonomic dysfunction (CVAD) is a major complication for a large proportion of Long COVID (LC) patients. The main phenotype of CVAD is postural orthostatic tachycardia syndrome (POTS), commonly observed as a sequalae of COVID infection, thus defining a subset of LC patients. POTS is a cardiovascular autonomic disorder characterized by an excessive heart rate (HR) increase and symptoms of orthostatic intolerance when assuming upright posture, occurring predominantly in young and middle-aged women. Since the start of COVID-19 pandemic it has been observed that up to 30% of patients with post-COVID-19 syndrome develop POTS with such symptoms as tachycardia, orthostatic intolerance, fatigue, and cognitive impairment. The heterogeneity of POTS symptoms makes the diagnosis and appropriate management of POTS more difficult and one of the first steps for clinicians is to develop and test relevant diagnostic methods for POTS.
Methods: Patients with persistent symptoms, 3 months after an acute SARS-CoV-2 infection were referred to the multi-disciplinary LC unit at a hospital in Sweden. Consecutive patients seen at this unit from 2021 to 2022 underwent a 24-h ECG recording. LC patients with POTS verified by active standing test and/or head-up tilt testing were prospectively enrolled in the study database and were compared with LC patients without POTS according to 3 specific analyses based on 24-h ECG recording : (1) cardiac autonomic activity expressed by heart rate variability, HRV (SDNN and RMSSD in ms) parameters, (2) awakening HR increase (HR mean 10 min before vs. 30 min after awakening) and (3) HR spikes (number/h if at least over than 30 bpm and at least during 30 s). Control group consisted of healthy subjects from 24-h ECG recordings database (HRV analysis) of a hospital in France. Data were expressed as mean (± standard deviation, SD) and frequencies (%).
Results: A total of 120 LC patients (mean age: 42.7 +/-9.97 y, 88% women) and 100 healthy subjects (mean age: 46.4 +/-10.2 y, 82% women) were included. LC with POTS (42%) was associated with (1) a decrease in most HRV parameters (mean SDNN: 86.8 +/-24.3 vs. 108.7 +/-24.1 ms, p=0.03), and the most reduced components were those related to the parasympathetic tone (mean RMSSD: 34,5 +/-20.4 vs. 45.6 +/-22.1 ms, p=0.04), (2) an abrupt and sustained increase in HR during the first 30 min after awakening (+30%, p<0.05) and (3) a higher number of HR spikes per h (1.4 +/-0.8 vs. 0.8 +/-0.7/h, p<0.001) compared with healthy subjects (HRV) and LC patients without POTS (awakenings and HR peaks) respectively.
Conclusion: A triple analysis of 24-h ECG recordings revealed presence of autonomic dysfunction in LC patients with POTS compared with those without POTS. This novel analysis may be introduced in the clinic for screening and therapy monitoring.

Source: D Hupin and others, Diagnostic value of 24-h ECG recording in Long COVID patients with postural orthostatic tachycardia syndrome, EP Europace, Volume 25, Issue Supplement_1, June 2023, euad122.626, https://doi.org/10.1093/europace/euad122.626 (Full text available as PDF file)

Autoantibody production is enhanced after mild SARS-CoV-2 infection despite vaccination in individuals with and without long COVID

Abstract:

Long COVID patients who experienced severe acute SARS-CoV-2 infection can present with humoral autoimmunity. However, whether mild SARS-CoV-2 infection increases autoantibody responses and whether vaccination can decrease autoimmunity in long COVID patients is unknown.

Here, we demonstrate that mild SARS-CoV-2 infection increases autoantibodies associated with systemic lupus erythematosus (SLE) and inflammatory myopathies in long COVID patients with persistent neurologic symptoms to a greater extent than COVID convalescent controls at 8 months post-infection. Furthermore, high titers of SLE-associated autoantibodies in long COVID patients are associated with impaired cognitive performance and greater symptom severity, and subsequent vaccination/booster does not decrease autoantibody titers.

In summary, we found that mild SARS-CoV-2 infection can induce persistent humoral autoimmunity in both long COVID patients and healthy COVID convalescents, suggesting that a reappraisal of vaccination and mitigation strategies is warranted.

Source: Visvabharathy L, Zhu C, Orban ZS, Yarnoff K, Palacio N, Jimenez M, Lim PH, Penaloza-MacMaster P, Koralnik IJ. Autoantibody production is enhanced after mild SARS-CoV-2 infection despite vaccination in individuals with and without long COVID. medRxiv [Preprint]. 2023 Apr 12:2023.04.07.23288243. doi: 10.1101/2023.04.07.23288243. PMID: 37090595; PMCID: PMC10120795. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10120795/ (Full text)