Racial, ethnic, and sex disparities in the incidence and cognitive symptomology of long COVID-19

Abstract:

Background: The pandemic has highlighted and exacerbated health inequities in both acute coronavirus disease 2019 (COVID-19) and its longer-term sequelae. Given the heterogeneity in definitions of long COVID and the lack of centralized registries of patients with the disease, little is known about the differential prevalence among racial, ethnic, and sex subgroups. This study examines long COVID among Black, White, Asian, and Hispanic Americans and evaluates differences in the associated cognitive symptomology.

Method: Data from four releases of the Census Bureau’s Household Pulse Survey detailing COVID-19 incidence and the duration and type of symptoms among a nationally representative sample of adults from June 1, 2022, through October 17, 2022, were combined. Binary logistic regression assessed the relative likelihood of long COVID among those who had been diagnosed COVID between racial, ethnic, and sex subgroups. Among those reporting long COVID, differences in the prevalence of difficulty understanding and difficulty remembering were assessed. Empirical models accounted for household, regional, vaccination, and insurance differences between respondents. Two-stage selection models were applied to test the robustness of the results.

Results: Among respondents who tested positive for COVID-19, Blacks (OR=1.097, CI=1.034-1.163), females (OR=1.849, CI=1.794-1.907), and Hispanics (OR=1.349, CI=1.286-1.414) were more likely to experience long COVID (symptoms lasting for 3 months or longer) compared to Whites, males, and non-Hispanics respectively. However, those with private health insurance (OR=0.634, CI=0.611-0.658) and who received the COVID vaccine (OR=0.901, CI=0.864-0.94) were less likely to have endured COVID symptoms than their counterparts. Symptoms of long COVID varied significantly between population subgroups. Compared to Whites, Blacks were more likely to have trouble remembering (OR=1.878, CI=1.765-1.808) while Hispanics were more likely to report difficult understanding (OR=1.827, CI=1.413, 2.362). Females, compared to males, were less likely to experience trouble understanding (OR=0.664, CI=0.537, 0.821), but more likely to report trouble remembering (OR=1.34, CI=1.237, 1.451).

Conclusions: Long COVID is more prevalent among Blacks, Hispanics, and females, but each group appears to experience long COVID differently. Therefore, additional research is needed to determine the best method to treat and manage this poorly understood condition.

Source: Jacobs MM, Evans E, Ellis C. Racial, ethnic, and sex disparities in the incidence and cognitive symptomology of long COVID-19. J Natl Med Assoc. 2023 Feb 13:S0027-9684(23)00025-1. doi: 10.1016/j.jnma.2023.01.016. Epub ahead of print. PMID: 36792456; PMCID: PMC9923441. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9923441/ (Full text)

Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study

Abstract:

Background and purpose: Long COVID with regard to the neurological system deserves more attention, as a surge of treated patients are being discharged from the hospital. As the dynamic changes in white matter after two years remain unknown, this characteristic was the focus of this study.

Methods: We investigated 17 recovered COVID-19 patients at two years after discharge. Diffusion tensor imaging, neurite orientation dispersion and density imaging were performed to identify white matter integrity and changes from one to two years after discharge. Data for 13 revisited healthy controls were collected as a reference. Subscales of the Wechsler Intelligence scale were used to assess cognitive function. Repeated-measures ANOVA was used to detect longitudinal changes in 17 recovered COVID-19 patients and 13 healthy controls after one-year follow-up. Correlations between diffusion metrics, cognitive function, and other clinical characteristics (i.e., inflammatory factors) were also analyzed.

Results: Longitudinal analysis showed the recovery trends of large-scale brain regions, with small-scale brain region deterioration from one year to two years after SARS-CoV-2 infection. However, persistent white matter abnormalities were noted at two years after discharge. Longitudinal changes of cognitive function showed no group difference. But cross-sectional cognitive difference between recovered COVID-19 patients and revisited HCs was detected. Inflammation levels in the acute stage correlated positively with white matter abnormalities and negatively with cognitive function. Moreover, the more abnormal the white matter was at two years, the greater was the cognitive deficit present.

Conclusion: Recovered COVID-19 patients showed longitudinal recovery trends of white matter. But also had persistent white matter abnormalities at two years after discharge. Inflammation levels in the acute stage may be considered predictors of cognition and white matter integrity, and the white matter microstructure acts as a biomarker of cognitive function in recovered COVID-19 patients. These findings provide an objective basis for early clinical intervention.

Source: Huang S, Zhou X, Zhao W, Du Y, Yang D, Huang Y, Chen Y, Zhang H, Yang G, Liu J, Luo H. Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study. Theranostics. 2023 Jan 1;13(2):724-735. doi: 10.7150/thno.79902. PMID: 36632218; PMCID: PMC9830428. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9830428/ (Full text)

Co-Ultramicronized Palmitoylethanolamide/Luteolin normalizes GABAB-ergic activity and cortical plasticity in long COVID-19 syndrome

Abstract:

Objective: Transcranial magnetic stimulation (TMS) studies showed that patients with cognitive dysfunction and fatigue after COVID-19 exhibit impaired cortical GABAB-ergic activity, as revealed by reduced long-interval intracortical inhibition (LICI).

Aim of this study was to test the effects of co-ultramicronized palmitoylethanolamide/luteolin (PEA-LUT), an endocannabinoid-like mediator able to enhance GABA-ergic transmission and to reduce neuroinflammation, on LICI.

Methods: Thirty-nine patients (26 females, mean age 49.9 ± 11.4 years, mean time from infection 296.7 ± 112.3 days) suffering from persistent cognitive difficulties and fatigue after mild COVID-19 were randomly assigned to receive either PEA-LUT 700mg + 70mg or PLACEBO, administered orally bid for eight weeks. The day before (PRE) and at the end of the treatment (POST), they underwent TMS protocols to assess LICI. We further evaluate short-latency afferent inhibition (SAI) and long-term potentiation (LTP)-like cortical plasticity.

Results: Patients treated with PEA-LUT but not with PLACEBO showed a significant increase of LICI and LTP-like cortical plasticity. SAI remained unaffected.

Conclusions: Eight weeks of treatment with PEA-LUT restore GABAB activity and cortical plasticity in long Covid patients.

Significance: This study confirms altered physiology of the motor cortex in long Covid and indicates PEA-LUT as a candidate for the treatment of this post-viral condition.

Source: Viviana Versace, Paola Ortelli, Sabrina Dezi, Davide Ferrazzoli, Alessia Alibardi, Ilenia Bonini, Michael Engl, Roberto Maestri, Martina Assogna, Valentina Ajello, Elke Pucks-Faes, Leopold Saltuari, Luca Sebastianelli, Markus Kofler, Giacomo Koch. Co-Ultramicronized Palmitoylethanolamide/Luteolin normalizes GABAB-ergic activity and cortical plasticity in long COVID-19 syndrome. Clinical Neurophysiology, 2022, ISSN 1388-2457, https://doi.org/10.1016/j.clinph.2022.10.017. https://www.sciencedirect.com/science/article/pii/S1388245722009385 (Full text)

 

Even mild COVID-19 may have long-term brain impacts

Research presented at the Alzheimer’s Association International Conference suggests even mild cases of COVID-19 may be associated with cognitive deficits months after recovery.

One Argentinian study of 234 seniors who previously had COVID-19 found that more than half showed some degree of cognitive impairment months later. One in three had severe “dementia-like” impairments in memory, attention and executive function — a much higher proportion than the 5%–8% of seniors in the general population who have dementia at a given time.

“This could be the start of a dementia-related epidemic fueled by this latest coronavirus,” stated presenting author Dr. Gabriel de Erausquin of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio. Researchers will follow the study participants over the next three to five years to see if these problems resolve or worsen.

The study didn’t look at participants’ cognitive performance prior to infection. However, those who lost their sense of smell while sick with COVID-19 tended to have more severe cognitive impairments months later, even if their other symptoms had been mild. According to de Erausquin, “once the virus has affected the olfactory bulb and caused effects there — changes that we can see with imaging — then other places in the brain that are connected to it also become abnormal, either in function or structure or both.”

Other research presented linked SARS-CoV-2 infection with an uptick in biomarkers of brain injury, neuroinflammation and Alzheimer disease. One American study of 310 patients with COVID-19 found that those with new neurological symptoms had higher levels of t-tau, NfL, GFAP, pTau-181, and UCH-L1 in their blood, as well as indicators of inflammation such as C-reactive protein, compared to patients without neurological symptoms. “These findings suggest patients who had COVID-19 may have an acceleration of Alzheimer-related symptoms and pathology,” according to presenting author Dr. Thomas Wisniewski of the New York University Grossman School of Medicine.

Earlier this year, de Erausquin and others reported that brain inflammation, stroke and other common complications of viral infections have longstanding links with neurodegenerative disorders. “Therefore, it seems likely to expect that COVID-19-related cardiovascular and cerebrovascular disease will also contribute to a higher longterm risk of cognitive decline and dementia in recovered individuals.”

Several recent studies have documented cognitive deficits post-COVID but like the research presented at the Alzheimer’s Association conference, data on patients’ performance before infection are lacking.

One British study of 81 337 people in EClinicalMedicine found that those who previously had COVID-19 tended to score lower on measures of intelligence, reasoning, problem-solving and planning than people who were never infected.

“These results accord with reports of long-COVID, where ‘brain fog,’ trouble concentrating and difficulty finding the correct words are common,” according to the authors. People who had been hospitalized and put on ventilators had the greatest impairments, but even those who had relatively mild symptoms showed some deficit.

In another study of 57 Americans receiving inpatient rehabilitation after hospitalization for COVID-19, four in five had mild to severe cognitive impairments. More than half had deficits in working memory, while two in five had impaired processing speed, divided attention, and trouble switching between mental tasks.

Similar deficits have also been noted in patients after recovery from other coronaviruses. A 2020 systematic review and meta-analysis found that delirium was common in the acute stage of severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and COVID-19. Following up with patients six weeks to 39 months later, more than 15% reported sleep disorders, mood swings, trouble concentrating, impaired memory and other mental challenges.

Based on this growing body of evidence, British researchers warned in March that health systems will likely see an “influx of patients with psychiatric and cognitive problems who were otherwise healthy prior to COVID-19.” They urged doctors to consider detailed cognitive evaluations for anyone reporting new neurological symptoms after infection with SARS-CoV-2.

In the meantime, the Alzheimer’s Association has formed an international consortium to study the long-term effects of COVID-19 on the brain.

“These new data point to disturbing trends showing COVID-19 infections leading to lasting cognitive impairment and even Alzheimer’s symptoms,” stated Heather Snyder of the Alzheimer’s Association. “It is imperative that we continue to study what this virus is doing to our bodies and brains.”

Source: Duong D. Even mild COVID-19 may have long-term brain impacts. CMAJ. 2021 Aug 30;193(34):E1360-E1361. doi: 10.1503/cmaj.1095958. PMID: 34462298; PMCID: PMC8432319.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8432319/ (Full text)

Effects of SARS-CoV-2 Infection on Attention, Memory, and Sensorimotor Performance

Abstract:

Background: Recovery after SARS-CoV-2 infection is extremely variable, with some individuals recovering quickly, and others experiencing persistent long-term symptoms or developing new symptoms after the acute phase of infection, including fatigue, poor concentration, impaired attention, or memory deficits. Many existing studies reporting cognitive deficits associated with SARS-CoV-2 infection are limited by the exclusive use of self-reported measures or a lack of adequate comparison groups.

Methods: Forty-five participants, ages 18-70, (11 Long-COVID, 14 COVID, and 20 No-COVID) underwent behavioral testing with the NIH Toolbox Neuro-Quality of Life survey and selected psychometric tests, including a flanker interference task and the d2 Test of Attention.

Results: We found greater self-reported anxiety, apathy, fatigue, emotional dyscontrol, sleep disturbance and cognitive dysfunction in COVID compared No-COVID groups. After categorizing COVID patients according to self-reported concentration problems, we observed declining performance patterns in multiple attention measures across No-COVID controls, COVID and Long-COVID groups. COVID participants, compared to No-COVID controls, exhibited worse performance on NIH Toolbox assessments, including the Eriksen Flanker, Nine-Hole Pegboard and Auditory Verbal Learning tests.

Conclusion: This study provides convergent evidence that previous SARS-CoV-2 infection is associated with impairments in sustained attention, processing speed, self-reported fatigue and concentration. The finding that some patients have cognitive and visuomotor dysfunction in the absence of self-reported problems suggests that SARS-CoV-2 infection can have unexpected and persistent subclinical consequences.

Source: O’Connor EE, Rednam N, O’Brien R, O’Brien S, Rock P, Levine A, Zeffiro TA. Effects of SARS-CoV-2 Infection on Attention, Memory, and Sensorimotor Performance. medRxiv [Preprint]. 2022 Sep 23:2022.09.22.22280222. doi: 10.1101/2022.09.22.22280222. PMID: 36172134; PMCID: PMC9516858. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9516858/ (Full text)

Memory alterations after COVID-19 infection: a systematic review

Abstract:

SARS-CoV-2 infection has a wide range of both acute and long-term symptoms. Memory alterations have been frequently reported in studies that explore cognition. The main objective of the systematic review is to update and further analyze the existing evidence of objective memory impairments in long-COVID-19 considering sample and study design characteristics, as well as to explore associations between memory performance and their epidemiological, clinical, and pathological features.

A total of 13 studies were identified by searching in PubMed, Web of Science, and PsycInfo databases up to May 6, 2022. Most studies evaluated verbal component of memory in the short-term and long-term recall up to 30 min and mainly performed a single assessment completed at 4-6 months after the infection. The samples mainly consisted of middle-aged adults that required hospitalization. Samples were not stratified by sex, age, and severity.

Poor verbal learning was reported in most cases (6-58%), followed by deficits in long-term (4-58%) and short-term (4-37%) verbal memory. Visuospatial component of memory was studied less than verbal component, showing impairment of long-term retention of visual items (10-49%). COVID-19 severity in the acute stage was not systematically associated with poor memory performance. Verbal memory deficits were associated with anxiety and depression.

The existing literature on objective memory assessment in long-COVID suggests further research is warranted to confirm memory dysfunction in association with epidemiological, pathological, and clinical factors, using both verbal and visuospatial tests, and exploring in deep long-term memory deficits.

Source: Llana T, Zorzo C, Mendez-Lopez M, Mendez M. Memory alterations after COVID-19 infection: a systematic review. Appl Neuropsychol Adult. 2022 Sep 15:1-14. doi: 10.1080/23279095.2022.2123739. Epub ahead of print. PMID: 36108666.  https://pubmed.ncbi.nlm.nih.gov/36108666/

COVCOG 2: Cognitive and Memory Deficits in Long COVID: A Second Publication From the COVID and Cognition Study

Abstract:

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been often characterized as a respiratory disease. However, it is increasingly being understood as an infection that impacts multiple systems, and many patients report neurological symptoms. Indeed, there is accumulating evidence for neural damage in some individuals, with recent studies suggesting loss of gray matter in multiple regions, particularly in the left hemisphere. There are several mechanisms by which the COVID-19 infection may lead to neurological symptoms and structural and functional changes in the brain, and cognitive problems are one of the most commonly reported symptoms in those experiencing Long COVID – the chronic illness following the COVID-19 infection that affects between 10 and 25% of patients. However, there is yet little research testing cognition in Long COVID.

The COVID and Cognition Study is a cross-sectional/longitudinal study aiming to understand cognitive problems in Long COVID. The first paper from the study explored the characteristics of our sample of 181 individuals who had experienced the COVID-19 infection, and 185 who had not, and the factors that predicted ongoing symptoms and self-reported cognitive deficits.

In this second paper from the study, we assess this sample on tests of memory, language, and executive function. We hypothesize that performance on “objective” cognitive tests will reflect self-reported cognitive symptoms. We further hypothesize that some symptom profiles may be more predictive of cognitive performance than others, perhaps giving some information about the mechanism. We found a consistent pattern of memory deficits in those that had experienced the COVID-19 infection, with deficits increasing with the severity of self-reported ongoing symptoms. Fatigue/Mixed symptoms during the initial illness and ongoing neurological symptoms were predictive of cognitive performance.

Source: Guo P, Benito Ballesteros A, Yeung SP, Liu R, Saha A, Curtis L, Kaser M, Haggard MP, Cheke LG. COVCOG 2: Cognitive and Memory Deficits in Long COVID: A Second Publication From the COVID and Cognition Study. Front Aging Neurosci. 2022 Mar 17;14:804937. doi: 10.3389/fnagi.2022.804937. PMID: 35370620; PMCID: PMC8967943. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8967943/ (Full study)

Neurocognitive Profiles in Patients With Persisting Cognitive Symptoms Associated With COVID-19

Abstract:

Objective: A subset of individuals with coronavirus disease 2019 (COVID-19) appears to develop persisting cognitive and medical symptoms. Research in the acute stages of illness, generally utilizing cognitive screening measures or case reports, suggests presence of deficits in attention and executive function. This observational study investigated cognitive functioning among individuals with persistent cognitive complaints about 5.5 months after COVID-19 infection.

Methods: Patients with polymerase chain reaction confirmed COVID-19 and persistent cognitive complaints underwent comprehensive in-person neuropsychological evaluations. Patients with prior neurological disorders were excluded. When diagnosed, 40% required hospitalization, 15% were in an intensive care unit, 10% needed mechanical ventilation, and 10% experienced delirium.

Results: This sample was predominately women (90%), White non-Hispanic (70%), with average education of 15 years. Mild cognitive deficits were seen on tests involving attention and processing speed or executive function. Seventy percent of patients were diagnosed with a mood disorder prior to COVID-19 infection. At the time of testing, 35%-40% endorsed moderate to severe mood symptoms and 85% noted significant fatigue as measured by the Fatigue Severity Scale.

Conclusions: The pattern of cognitive deficits, although mild, is consistent with prior research at the acute stage of the illness. These findings suggest that psychological factors and other persisting symptoms (e.g., sleep, fatigue) may play a significant role in subjective cognitive complaints in patients with persisting complaints post COVID-19 who did not require intensive treatment. These patients would likely benefit from resources to manage persisting or new mood symptoms and compensatory strategies for the cognitive inefficiencies they experience.

Source: Krishnan K, Miller AK, Reiter K, Bonner-Jackson A. Neurocognitive Profiles in Patients With Persisting Cognitive Symptoms Associated With COVID-19. Arch Clin Neuropsychol. 2022 Feb 5:acac004. doi: 10.1093/arclin/acac004. Epub ahead of print. PMID: 35136912. https://academic.oup.com/acn/advance-article/doi/10.1093/arclin/acac004/6522998 (Full text)

Chronic fatigue syndrome and cognitive deficit are associated with acute-phase neuropsychiatric manifestations of COVID-19: A 9-month follow-up study

Abstract:

The prevalence of long-COVID symptoms is rising but it is not still possible to predict which patients will present them, and which types of symptoms they will present. We followed up 95 patients with confirmed COVID-19 for 9 months to identify and characterize long-COVID symptoms.

Easy fatigability was the most common symptom (51.04%), followed by anxiety (38.54%), dyspnea (38.54%), and new-onset headache (38.54%). There was no association between COVID-19 severity in the acute phase and the number of long-COVID symptoms (F(1,93) = 0.75, p = 0.45), and cognitive function (MoCA) scores (F(1,90) = 0.073, p = 0.787) at follow-up. Being female (F(1,92) = – 2.27, p = 0.02), having a higher number of symptoms (F(1,93) = 2.76, p = 0.0068), and experiencing constitutional neuropsychiatric symptoms (F(1,93) = 2.529, p = 0.01) in the acute phase were associated with having chronic fatigue syndrome at follow-up.

Moreover, constitutional neuropsychiatric symptoms in the acute phase were associated with a lower MoCA score (F(1,93) = 10.84, p = 0.001) at follow-up. Specific clinical presentations such as constitutional neuropsychiatric symptoms in the acute phase might be predictors of debilitating long-COVID symptoms such as chronic fatigue syndrome and cognitive deficits.

Source: Mirfazeli FS, Sarabi-Jamab A, Pereira-Sanchez V, Kordi A, Shariati B, Shariat SV, Bahrami S, Nohesara S, Almasi-Dooghaee M, Faiz SHR. Chronic fatigue syndrome and cognitive deficit are associated with acute-phase neuropsychiatric manifestations of COVID-19: A 9-month follow-up study. Neurol Sci. 2022 Jan 21. doi: 10.1007/s10072-021-05786-y. Epub ahead of print. PMID: 35059902. https://pubmed.ncbi.nlm.nih.gov/35059902/