Icahn Study Shows That Cognitive Decline And Brain Fog Can Persist Up To 8 Months After Contracting COVID-19 And The Scale Is Astounding!
Cognitive Issues and COVID-19:
A new study by researchers from Icahn School of Medicine at Mount Sinai, New York has shown that that cognitive decline and brain fog can persist up to 8 months after contracting COVID-19!
Individuals who have survived COVID-19 frequently complain of cognitive dysfunction, which has been described as brain fog. The prevalence of post–COVID-19 cognitive impairment and the association with disease severity are not well characterized.
Past studies on the topic have been limited by small sample sizes and suboptimal measurement of cognitive functioning.
The Cognitive Issues-COVID-19
study team investigated rates of cognitive impairment in survivors of COVID-19 who were treated in outpatient, emergency department (ED), or inpatient hospital settings.
The study team analyzed data in this cross-sectional study from April 2020 through May 2021 from a cohort of patients with COVID-19 followed up through a Mount Sinai Health System registry. Study participants were 18 years or older tested positive for SARS-CoV-2 or had serum antibody positivity, and had no history of dementia. Participant demographic characteristics (eg, age, race, and ethnicity) were collected via self-report. Cognitive functioning was assessed using well-validated neuropsychological measures: Number Span forward (attention) and backward (working memory), Trail Making Test Part A and Part B (processing speed and executive functioning, respectively), phonemic and category fluency (language), and the Hopkins Verbal Learning Test–Revised (memory encoding, recall, and recognition). The Mount Sinai Health System Institutional Review Board approved this study, and informed consent was obtained from study participants. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE
) reporting guideline.
The average mean (IQR) age of 740 participants was 49 (38-59) years, 63% (n = 464) were women, and the mean (SD) time from COVID-19 diagnosis was 7.6 (2.7) months.
The study findings showed that the most prominent deficits were in processing speed (18%, n = 133), executive functioning (16%, n = 118), phonemic fluency (15%, n = 111) and category fluency (20%, n = 148), memory encoding (24%, n = 178), and memory recall (23%, n = 170).
The study findings also showed that hospitalized patients were more likely to have impairments in attention (odds ratio [OR]: 2.8; 95% CI: 1.3-5.9), executive functioning (OR: 1.8; 95% CI: 1.0-3.4), category fluency (OR: 3.0; 95% CI: 1.7-5.2), memory encoding (OR: 2.3; 95% CI: 1.3-4.1), and memory recall (OR: 2.2; 95% CI: 1.3-3.8) than those in the outpatient group.
The findings also showed that patients treated in the ED were more likely to have impaired category fluency (OR: 1.8; 95% CI: 1.1-3.1) and memory encoding (OR: 1.7; 95% CI: 1.0-3.0) than those treated in the outpatient setting. No significant differences in impairments in other domains were observed between groups.
The study findings were published in the peer reviewed journal: JAMA Network.
The study alarmingly showed that high rates of cognitive dysfunction or brain fog have been found an average of 7.6 months after patients have been treated for COVID-19.
The clinical study of 740 individuals with no prior history of memory problems included people treated in the outpatient setting as well as those who were admitted to a hospital or treated in emergency departments (EDs).
The study team notes that, although older populations are well known to be susceptible to cognitive impairment after a serious illness, this study has implications for younger people as well.
Lead researcher Dr Jacqueline H. Becker, PhD, a clinical neuropsychologist at the Division of General Internal Medicine, Icahn School of Medicine told Thailand Medical News, "Many individuals believe that they will survive COVID and they'll be just fine and for the majority of the population I think that's true. But I think our study findings suggests there are long-term cognitive repercussions from COVID that may impact individuals across various age groups and the spectrum of disease severity."
The most commonly reported deficits were in processing speed, executive functioning, phonemic fluency, category fluency (tested by listing as many animals as you can in a minute, for instance, memory encoding, and memory recall.
The study findings however showed that deficits varied by the treatment setting.
Interestingly hospitalized patients were more likely to have impairments in attention (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.3 - 5.9), executive functioning (OR, 1.8; 95% CI, 1.0 - 3.4), category fluency (OR, 3.0; 95% CI, 1.7 - 5.2), memory encoding (OR, 2.3; 95% CI, 1.3 - 4.1), and memory recall (OR, 2.2; 95% CI, 1.3 - 3.8) than those in the outpatient group.
Also, patients treated in the ED were more likely to have impaired category fluency (OR, 1.8; 95% CI, 1.1 - 3.1) and memory encoding (OR, 1.7; 95% CI, 1.0 - 3.0) than outpatients. No significant differences in impairments in other domains were observed between groups.
Dr Helen Lavretsky, MD, professor in-residence, Department of Psychiatry, University of California, Los Angeles, and a geriatric integrative psychiatrist, told media that the numbers in this study confirm trends she is seeing in her post-COVID clinic.
Dr Lavretsky said, "It is devastating for young individuals, especially, who were in their best health up until they got COVID. Some improve right after COVID, but then lapse and brain fog or cognitive impairment is one of the top three most common symptoms. Others include fatigue and anxiety."
Dr Lavretsky said the research echoes the question of other studies in how long these symptoms will last. "Is it forever? We're coming up on almost two years of the same symptoms."
Dr Lavretsky stressed, "The scale of how COVID-19 affects the cognitive functions of individuals is simply astounding especially in younger people. Normally people of this age don't have this type of impairment. Maybe in the single-digit proportion. This is not unlike other viral diseases like HIV, for instance or Lyme Disease. What is really shocking is the scale ie so many have it."
Dr Lavretsky noted that because so many individuals have been infected with COVID-19 the numbers with these cognitive effects translate to hundreds of thousands, which will come with great cost to the healthcare system and work productivity losses.
She warned, "Disability will break the bank. Within the next year, we will all realize how tremendous this problem is."
Dr Tracy Vannorsdall, PhD, associate professor of psychiatry and behavioral sciences, Johns Hopkins Medicine, Baltimore, Maryland, also told media that she is also seeing similar effects after COVID illness.
This research shows that the lasting effects are prevalent at all levels of illness from COVID-19, Vannorsdall said, adding that the findings also add concern to what happens to young COVID survivors as they age.
Dr Vannorsdall added, "Some of the proposed mechanisms for COVID-related cognitive difficulties overlap with those we see in neuro degenerative conditions. There is an eye toward examining folks and following them long-term to get a sense of whether earlier-life COVID will put people at higher risk for cognitive difficulties later on."
Dr Vannorsdall said the findings of this study suggest clinicians should be asking more questions about cognitive function and memory.
She said that one of the strengths of this study is that Becker's team used a more detailed cognitive battery than previous literature has shown. The kinds of impairment are differentiated so clinicians can more easily target treatment and rehabilitation to areas of weakness.
All study participants were at least 18 years old, spoke English or Spanish, tested positive for SARS-CoV-2 or were positive for antibodies, and had no history of dementia. Age, race, and ethnicity were self-reported.
The study team used well-validated neuropsychological tools to measure cognitive function: Digit Span Forward (attention) and Backward (working memory), Trail Making Test Part A (processing speed) and Part B (executive functioning), phonemic and category fluency (language), and the Hopkins Verbal Learning Test-Revised (memory encoding, recall, and recognition).
Dr Becker added, "Past studies on the topic have been limited by small sample sizes and suboptimal measurement of cognitive functioning.”
The study team notes that a limitation of the study is that some participants may have presented to Mount Sinai Health System because of health concerns, which could introduce sampling bias.
Dr Becker said they will continue to follow these participants through the registry long-term, and further work will compare them with controls.
Dr Becker added, “Findings may help determine opportunities for intervention and treating reversible symptoms, such as depression, which may contribute to cognitive impairment. Cognitive screening of post-COVID patients as standard of care may be prudent regardless of COVID severity. At the system level, I think there's also a great need to implement culturally competent cognitive services to better serve racially and ethnically diverse patients."
The emerging seriousness and vast medical symptoms associated with Long COVID or PASC (Post-acute Sequelae of COVID-19) is expected to cause a serious impact on public healthcare all over the world in coming months and years.
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