Tag: cognitive impairment

Cognitive impairment after Long COVID-19: Current Evidence and Perspectives

Abstract:

COVID-19 is a respiratory infectious disease caused by the SARS-CoV-2 virus. Most patients recover after treatment, but COVID-19 treatment may lead to cognitive impairment. Recent studies have found that some recoverers experience cognitive impairments such as decreased memory and attention, and sleep disorder, indicating that COVID-19 may have longerterm effects on cognitive function.

Studies have found that COVID-19 may cause cognitive decline by damaging key brain regions such as the hippocampus and anterior cingulate cortex. Studies have also found that COVID-19 patients have active neuroinflammation, mitochondrial dysfunction, and microglial activation, suggesting that neuroinflammation, mitochondrial stress, and neurodegenerative changes may be potential mechanisms leading to cognitive impairment.

In summary, the possibility of cognitive impairment after COVID-19 treatment deserves close attention. Large-scale follow-up studies will help further explore the impact of COVID-19 on cognitive function and provide evidence to support clinical treatment and rehabilitation practices. Neuropathological and biological studies can explore precise mechanisms in-depth and provide a theoretical basis for prevention, treatment, and intervention research.

Given the risks of long-term COVID-19 and reinfection, it is necessary to integrate basic and clinical research data to maximize the maintenance of patient’s cognitive function and life quality. This also provides important experience in responding to similar public health events. This article integrates clinical and basic evidence of cognitive impairment after COVID-19 and discusses potential mechanisms and future research directions.

Source: Zhi-Tao Li, ZHANG ZHEN, Zhuoya Zhang, Zhi-Yong Wang, Hao Li. Cognitive impairment after Long COVID-19: Current Evidence and Perspectives. Front. Neurol. Sec. Neuroinfectious Diseases. Volume 14 – 2023 | doi: 10.3389/fneur.2023.1239182 https://www.frontiersin.org/articles/10.3389/fneur.2023.1239182/abstract

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)

Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study)

Abstract:

Purpose: Approximately 96% of patients with postural orthostatic tachycardia syndrome (PoTS) report cognitive complaints. We investigated whether cognitive function is impaired during sitting and active standing in 30 patients with PoTS compared with 30 healthy controls (HCs) and whether it will improve with the counter manoeuvre of leg crossing.

Methods: In this prospective pilot study, patients with PoTS were compared to HCs matched for age, sex, and educational level. Baseline data included norepinephrine plasma levels, autonomic testing and baseline cognitive function in a seated position [the Montreal Cognitive Assessment, the Leistungsprüfsystem (LPS) subtests 1 and 2, and the Test of Attentional Performance (TAP)]. Cognitive functioning was examined in a randomized order in supine, upright and upright legs crossed position. The primary outcomes were the cognitive test scores between HCs and patients with PoTS at baseline testing, and among the different body positions.

Results: Patients with PoTS had impaired attention (TAP median reaction time) in the seated position and impaired executive functioning (Stroop) while standing compared with HC. Stroop was influenced by position (supine versus upright versus upright legs crossed) only in the PoTS group. Leg crossing did not result in an improvement in executive function. In patients with PoTS, there was a negative correlation of Stroop with norepinephrine plasma levels while standing.

Conclusion: Compared with HCs, PoTS participants showed impaired cognitive attention and executive function in the upright position that did not improve in the legs crossed position. Data provide further evidence for orthostatic cognitive deterioration in patients with PoTS.

Trial Registration Information: The study was registered at ClinicalTrials.gov (NCT03681080).

Source: Maier, A., Schopen, L., Thiel, J.C. et al. Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study). Clin Auton Res (2023). https://doi.org/10.1007/s10286-023-00950-0 https://link.springer.com/article/10.1007/s10286-023-00950-0 (Full text)

Neuropsychological deficits in patients with persistent COVID-19 symptoms: a systematic review and meta-analysis

Abstract:

Long-term persistent symptoms of COVID-19 affect 30-80% of patients who have recovered from the disease and may continue for a long time after the disease has been overcome. The duration of these symptoms over time might have consequences that affect different aspects of health, such as cognitive abilities.

The main objective of this systematic review and meta-analysis was to objectify the persistent COVID-19 cognitive deficits after acute phase of infection and to summarize the existing evidence. Additionally, we aimed to provide a comprehensive overview to further understand and address the consequences of this disease. Our protocol was registered in PROSPERO (CRD42021260286).

Systematic research was conducted in the Web of Science, MEDLINE, PubMed, PsycINFO, Scopus, and Google Scholar databases from January 2020 to September 2021. Twenty-five studies were included, six of which were analyzed for the meta-analysis, and consisted of 175 patients who had recovered from COVID-19 and 275 healthy individuals. Analyses of cognitive performance of post-COVID-19 patients and healthy volunteers were compared using a random-effects model.

The results showed an overall medium-high effect size (g = -.68, p = .02) with a 95% CI (-1.05 to -.31), with a significantly moderate level of heterogeneity among studies (Z = 3.58, p < .001; I2 = 63%). The results showed that individuals who had recovered from COVID-19 showed significant cognitive deficits compared to controls.

Future studies should carefully assess the long-term progression of cognitive impairments in patients with persistent COVID-19 symptoms, as well as the effectiveness of rehabilitation interventions. Nevertheless, there is an urgent need to know the profile to speed up development of prevention plans as well as specific interventions. Since more information is being obtained and more studies are being conducted on the subject, the need to examine this symptomatology multidisciplinary to achieve greater scientific evidence of its incidence and prevalence has become increasingly clear.

Source: Sobrino-Relaño S, Balboa-Bandeira Y, Peña J, Ibarretxe-Bilbao N, Zubiaurre-Elorza L, Ojeda N. Neuropsychological deficits in patients with persistent COVID-19 symptoms: a systematic review and meta-analysis. Sci Rep. 2023 Jun 26;13(1):10309. doi: 10.1038/s41598-023-37420-6. PMID: 37365191; PMCID: PMC10293265. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10293265/ (Full text)

Cognitive impairment in post-acute sequelae of COVID-19 and short duration myalgic encephalomyelitis patients is mediated by orthostatic hemodynamic changes

Introduction: Cognitive impairment is experienced by people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of COVID-19 (PASC). Patients report difficulty remembering, concentrating, and making decisions. Our objective was to determine whether orthostatic hemodynamic changes were causally linked to cognitive impairment in these diseases.

Methods: This prospective, observational cohort study enrolled PASC, ME/CFS, and healthy controls. All participants underwent clinical evaluation and assessment that included brief cognitive testing before and after an orthostatic challenge. Cognitive testing measured cognitive efficiency which is defined as the speed and accuracy of subject’s total correct responses per minute. General linear mixed models were used to analyze hemodynamics and cognitive efficiency during the orthostatic challenge. Additionally, mediation analysis was used to determine if hemodynamic instability induced during the orthostatic challenge mediated the relationship between disease status and cognitive impairment.

Results: Of the 276 participants enrolled, 256 were included in this study (34 PASC, 71 < 4 year duration ME/CFS, 69 > 10 year ME/CFS duration, and 82 healthy controls). Compared to healthy controls, the disease cohorts had significantly lower cognitive efficiency scores immediately following the orthostatic challenge. Cognitive efficiency remained low for the >10 year ME/CFS 2 and 7 days after orthostatic challenge. Narrow pulse pressure less than 25% of systolic pressure occurred at 4 and 5 min into the orthostatic challenge for the PASC and ME/CFS cohorts, respectively. Abnormally narrow pulse pressure was associated with slowed information processing in PASC patients compared to healthy controls (−1.5, p = 0.04). Furthermore, increased heart rate during the orthostatic challenge was associated with a decreased procedural reaction time in PASC and < 4 year ME/CFS patients who were 40 to 65 years of age.

Discussion: For PASC patients, both their disease state and hemodynamic changes during orthostatic challenge were associated with slower reaction time and decreased response accuracy during cognitive testing. Reduced cognitive efficiency in <4 year ME/CFS patients was associated with higher heart rate in response to orthostatic stress. Hemodynamic changes did not correlate with cognitive impairment for >10 year ME/CFS patients, but cognitive impairment remained. These findings underscore the need for early diagnosis to mitigate direct hemodynamic and other physiological effects on symptoms of cognitive impairment.

Source: Day Heather, Yellman Brayden, Hammer Sarah, Rond Candace, Bell Jennifer, Abbaszadeh Saeed, Stoddard Greg, Unutmaz Derya, Bateman Lucinda, Vernon Suzanne D. Cognitive impairment in post-acute sequelae of COVID-19 and short duration myalgic encephalomyelitis patients is mediated by orthostatic hemodynamic changes. Frontiers in Neuroscience, VOLUME=17, 2023. DOI=10.3389/fnins.2023.1203514. ISSN=1662-453X. https://www.frontiersin.org/articles/10.3389/fnins.2023.1203514 (Full text)

Long COVID: Plasma levels of neurofilament light chain in mild COVID-19 patients with neurocognitive symptoms

Abstract:

It is well known the potential of severe acute respiratory coronavirus type 2 (SARS-CoV-2) infection to induce post-acute sequelae, a condition called Long COVID. This syndrome includes several symptoms, but the central nervous system (CNS) main one is neurocognitive dysfunction. Recently it has been demonstrated the relevance of plasma levels of neurofilament light chain (pNfL), as a biomarker of early involvement of the CNS in COVID-19.

The aim of this study was to investigate the relationship between pNfL in patients with post-acute neurocognitive symptoms and the potential of NfL as a prognostic biomarker in these cases. A group of 63 long COVID patients ranging from 18 to 59 years-old were evaluated, submitted to a neurocognitive battery assessment, and subdivided in different groups, according to results. Plasma samples were collected during the long COVID assessment and used for measurement of pNfL with the Single molecule array (SIMOA) assays. Levels of pNfL were significantly higher in long COVID patients with neurocognitive symptoms when compared to HC (p = 0.0031).

Long COVID patients with cognitive impairment and fatigue symptoms presented higher pNfL levels when compared to long COVID patients without these symptoms, individually and combined (p = 0.0263, p = 0.0480, and 0.0142, respectively). Correlation analysis showed that levels of cognitive lost and exacerbation of fatigue in the neurocognitive evaluation had a significative correlation with higher pNfL levels (p = 0.0219 and 0.0255, respectively). Previous reports suggested that pNfL levels are related with higher risk of severity and predict lethality of COVID-19.

Our findings demonstrate that SARS-CoV-2 infection seems to have a long-term impact on the brain, even in patients who presented mild acute disease. NfL measurements might be useful to identify CNS involvement in long COVID associated with neurocognitive symptoms and to identify who will need continuous monitoring and treatment support.

Source: Gutman E, Salvio A, Fernandes R, et al. Long COVID: Plasma levels of neurofilament light chain in mild COVID-19 patients with neurocognitive symptoms. Research Square; 2023. DOI: 10.21203/rs.3.rs-2921879/v1. https://www.researchsquare.com/article/rs-2921879/v1 (Full text)

Mouse Adapted SARS-CoV-2 Model Induces “Long-COVID” Neuropathology in BALB/c Mice

Abstract:

The novel coronavirus SARS-CoV-2 has caused significant global morbidity and mortality and continues to burden patients with persisting neurological dysfunction. COVID-19 survivors develop debilitating symptoms to include neuro-psychological dysfunction, termed “Long COVID”, which can cause significant reduction of quality of life. Despite vigorous model development, the possible cause of these symptoms and the underlying pathophysiology of this devastating disease remains elusive.

Mouse adapted (MA10) SARS-CoV-2 is a novel mouse-based model of COVID-19 which simulates the clinical symptoms of respiratory distress associated with SARS-CoV-2 infection in mice. In this study, we evaluated the long-term effects of MA10 infection on brain pathology and neuroinflammation. 10-week and 1-year old female BALB/cAnNHsd mice were infected intranasally with 10 4 plaque-forming units (PFU) and 10 3 PFU of SARS-CoV-2 MA10, respectively, and the brain was examined 60 days post-infection (dpi).

Immunohistochemical analysis showed a decrease in the neuronal nuclear protein NeuN and an increase in Iba-1 positive amoeboid microglia in the hippocampus after MA10 infection, indicating long-term neurological changes in a brain area which is critical for long-term memory consolidation and processing. Importantly, these changes were seen in 40-50% of infected mice, which correlates to prevalence of LC seen clinically.

Our data shows for the first time that MA10 infection induces neuropathological outcomes several weeks after infection at similar rates of observed clinical prevalence of “Long COVID”. These observations strengthen the MA10 model as a viable model for study of the long-term effects of SARS-CoV-2 in humans. Establishing the viability of this model is a key step towards the rapid development of novel therapeutic strategies to ameliorate neuroinflammation and restore brain function in those suffering from the persistent cognitive dysfunction of “Long-COVID”.

Source: Gressett TE, Leist SR, Ismael S, Talkington G, Dinnon KH, Baric RS, Bix G. Mouse Adapted SARS-CoV-2 Model Induces “Long-COVID” Neuropathology in BALB/c Mice. bioRxiv [Preprint]. 2023 Mar 20:2023.03.18.533204. doi: 10.1101/2023.03.18.533204. PMID: 36993423; PMCID: PMC10055301. https://www.biorxiv.org/content/10.1101/2023.03.18.533204v1.full (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)

Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction

Abstract:

Objectives: There is no established treatment for chronic fatigue and various cognitive dysfunctions (brain fog) caused by long coronavirus disease 2019 (COVID-19). We aimed to clarify the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for treating these symptoms.

Methods: High-frequency rTMS was applied to occipital and frontal lobes in 12 patients with chronic fatigue and cognitive dysfunction 3 months after severe acute respiratory syndrome coronavirus 2 infection. Before and after ten sessions of rTMS, Brief Fatigue Inventory (BFI), Apathy Scale (AS), and Wechsler Adult Intelligence Scale-fourth edition (WAIS4) were determined and N-isopropyl-p-[123I]iodoamphetamine single photon emission computed tomography (SPECT) was performed.

Results: Twelve subjects completed ten sessions of rTMS without adverse events. The mean age of the subjects was 44.3 ± 10.7 years, and the mean duration of illness was 202.4 ± 114.5 days. BFI, which was 5.7 ± 2.3 before the intervention, decreased significantly to 1.9 ± 1.8 after the intervention. The AS was significantly decreased after the intervention from 19.2 ± 8.7 to 10.3 ± 7.2. All WAIS4 sub-items were significantly improved after rTMS intervention, and the full-scale intelligence quotient increased from 94.6 ± 10.9 to 104.4 ± 13.0. Hypoperfusion in the bilateral occipital and frontal lobes observed on SPECT improved in extent and severity after ten sessions of rTMS.

Conclusions: Although we are still in the early stages of exploring the effects of rTMS, the procedure has the potential for use as a new non-invasive treatment for the symptoms of long COVID.

Source: Sasaki N, Yamatoku M, Tsuchida T, Sato H, Yamaguchi K. Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction. Prog Rehabil Med. 2023 Feb 28;8:20230004. doi: 10.2490/prm.20230004. PMID: 36861061; PMCID: PMC9968785. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9968785/ (Full text)

Association of Post-COVID-19 Condition Symptoms and Employment Status

Abstract:

Importance: Little is known about the functional correlates of post-COVID-19 condition (PCC), also known as long COVID, particularly the relevance of neurocognitive symptoms.

Objective: To characterize prevalence of unemployment among individuals who did, or did not, develop PCC after acute infection.

Design, setting, and participants: This survey study used data from 8 waves of a 50-state US nonprobability internet population-based survey of respondents aged 18 to 69 years conducted between February 2021 and July 2022.

Main outcomes and measures: The primary outcomes were self-reported current employment status and the presence of PCC, defined as report of continued symptoms at least 2 months beyond initial month of symptoms confirmed by a positive COVID-19 test.

Results: The cohort included 15 308 survey respondents with test-confirmed COVID-19 at least 2 months prior, of whom 2236 (14.6%) reported PCC symptoms, including 1027 of 2236 (45.9%) reporting either brain fog or impaired memory. The mean (SD) age was 38.8 (13.5) years; 9679 respondents (63.2%) identified as women and 10 720 (70.0%) were White. Overall, 1418 of 15 308 respondents (9.3%) reported being unemployed, including 276 of 2236 (12.3%) of those with PCC and 1142 of 13 071 (8.7%) of those without PCC; 8229 respondents (53.8%) worked full-time, including 1017 (45.5%) of those with PCC and 7212 (55.2%) without PCC. In survey-weighted regression models excluding retired respondents, the presence of PCC was associated with a lower likelihood of working full-time (odds ratio [OR], 0.71 [95% CI, 0.63-0.80]; adjusted OR, 0.84 [95% CI, 0.74-0.96]) and with a higher likelihood of being unemployed (OR, 1.45 [95% CI, 1.22-1.73]; adjusted OR, 1.23 [95% CI, 1.02-1.48]). The presence of any cognitive symptom was associated with lower likelihood of working full time (OR, 0.70 [95% CI, 0.56-0.88]; adjusted OR, 0.75 [95% CI, 0.59-0.84]).

Conclusions and relevance: PCC was associated with a greater likelihood of unemployment and lesser likelihood of working full time in adjusted models. The presence of cognitive symptoms was associated with diminished likelihood of working full time. These results underscore the importance of developing strategies to treat and manage PCC symptoms.

Source: Perlis RH, Lunz Trujillo K, Safarpour A, Santillana M, Ognyanova K, Druckman J, Lazer D. Association of Post-COVID-19 Condition Symptoms and Employment Status. JAMA Netw Open. 2023 Feb 1;6(2):e2256152. doi: 10.1001/jamanetworkopen.2022.56152. PMID: 36790806; PMCID: PMC9932847. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9932847/(Full text)