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Understanding and Managing COVID-19 “Brain Fog”

Rob Smither • Apr 01, 2021


Long after their fever, cough, or other acute symptoms of COVID-19 have passed, some people experience lingering cognitive issues, such as difficulty concentrating or thinking clearly.


This so-called “brain fog” is emerging as one of the most vexing long-term problems encountered by people who otherwise have recovered from their coronavirus infection.


In a recent interview, board-certified neuropsychologist Anthony De Marco, PsyD, ABPP-CN, discussed the nature of “brain fog,” its occurrence not only in COVID-19 but in association with many illnesses, potential risk factors and causes, and approaches to evaluating and managing the issue.


Dr. De Marco, who practices with IGEA Brain, Spine & Orthopedics, also outlined approaches that all people can take to enhance their cognitive function, and explained how he assesses the neurocognitive, emotional, and behavioral complications of a wide range of neurological conditions, as well as age-related cognitive concerns.


Q: There has been considerable media attention to people experiencing “brain fog” in the aftermath of COVID-19. What exactly is this syndrome?


It is important to start by acknowledging that much of what we know at this point is preliminary and developing. However, we do know that there are neurological and neuropsychological symptoms associated with COVD-19 infection.


These symptoms may be mild – such as headaches, fatigue, or loss of taste and smell. In other cases, the symptoms are more severe, and can include confusion or delirium, stroke, seizures, encephalitis or meningitis, or cognitive and emotional symptoms, some of which are more unique to this virus.


“Brain fog” is not an actual condition or formal medical diagnosis, nor is it specific to COVID-19. The term has been used to describe changes in thinking following many critical illnesses, including those that require intensive care treatment. People have reported “brain fog” after stroke, decreased oxygen to the brain, concussion, and treatment with chemotherapy and other medications. So it is an extremely nonspecific constellation or group of cognitive symptoms.


Q: What are the main types of cognitive and emotional symptoms people are experiencing following COVID-19?


First, it is important to emphasize that many individuals will experience no significant cognitive or emotional symptoms and make a nice, unremarkable recovery. Also, when individuals do have cognitive symptoms, they may be very mild and transient in nature, or they can be more chronic.


The cognitive symptoms described by individuals who have had COVID-19 and seen in the literature on similar conditions typically fall into three categories:


  • inattention and distractibility, with difficulty focusing for extended periods of time;
  • slowed information processing, meaning that the process of taking information in and acting on it is slower, inaccurate, and/or inefficient; and,
  • executive dysfunction, which is when our ability to problem-solve, plan and organize, and multitask becomes compromised.


Disruptions in these processes may contribute to memory difficulties that impact daily functioning, which is what most patients and/or their family members notice, and prompt them to seek medical attention/treatment.


Beyond these symptoms, which have driven the discussion of “brain fog,” we know that individuals with a history of psychological illness are at increased risk for infection with COVID-19, and that having been infected with COVID-19 increases one’s risk for psychological distress. Most commonly seen are symptoms of depression and anxiety, with the latter occurring more frequently in women.


Additionally, there may be an increased risk for post-traumatic stress disorder (PTSD) in individuals infected with COVID-19, especially those who were critically ill, isolated, and hospitalized in intensive care units. I think it is important to note, generally speaking, that surveys have shown an elevation of depression, anxiety, and PTSD symptomatology across the general population related to the COVID-19 pandemic, not only due to the fear of infection for oneself and loved ones, but also due to the financial, occupational, and social impact and burden of the pandemic.


In my own practice, I have seen an increased rate of depressive and anxiety-related symptoms in patients over the past year due to the pandemic. Most of these individuals were not infected with the virus. It is important for everyone to know, whether or not they were infected with the virus, that mental health resources are available and that treatment is a telephone call away.


Q: What do we know at this point about factors that may increase a COVID-19 patient’s risk for experiencing “brain fog?” Also, roughly what percentage of people with COVID-19 are affected, and what is known about the potential causes of the condition?


I think it is safe to say, with all other things being equal, that illness severity and the presence of significant respiratory distress, such as patients requiring ICU admission with mechanical ventilation, as well as those with clear neurological involvement (e.g., stroke, seizures, microbleeds in the brain and stroke, and encephalitis or meningitis), are going to be at greater risk for persisting, long-term cognitive symptoms.


There are data from other serious illnesses showing that approximately 25% of individuals who were discharged after being mechanically ventilated for significant respiratory distress go on to experience chronic cognitive impairment, psychological symptoms such depression and anxiety, and a reduced quality of life. So, the most critically ill individuals will be at greater risk for greater cognitive impairment. A caveat to this is that previous studies, including those of other coronaviruses, typically focused on the “sickest of the sick.” Individuals with mild symptoms were not studied. Therefore, it will be important to study COVID-19 patients across the spectrum of illness severity, including mild cases, especially when considering a vague group of symptoms such as “brain fog.”


While age is a general risk factor for cognitive impairment, we do not know a lot about the impact of other demographic variables – such race or ethnicity, socioeconomic status, gender, access to healthcare, or pre-infection intellectual functioning – on risk for this syndrome. This will be an important area of ongoing research.


It is important to keep in mind that the virus presents very differently, with some individuals experiencing respiratory symptoms while others may exhibit gastrointestinal symptoms. So the virus can look very different even among individuals of similar demographic backgrounds, and this will likely influence the likelihood of neurological or neuropsychological symptoms.


Lastly, along with illness severity and demographic variables, comorbid medical and psychiatric symptoms need to be taken into consideration. Certain pre-existing medical or neurological conditions will likely increase the risk of post-COVID-19 cognitive and emotional symptoms.


As for the mechanisms involved, there are likely primary and secondary mechanisms for neurological and neuropsychological symptoms. It has been demonstrated that coronaviruses can be neuroinvasive and even hang around the central nervous system after the infection has cleared, creating the opportunity for long-term neurological and neuropsychological symptoms. Secondary mechanisms for symptoms include conditions such as stroke, seizures, hypoxia, or even treatment-related effects.


Q. When should people experiencing symptoms of “brain fog” seek a medical evaluation?


At this point, because there is no established standard of care, this is a very individualistic question and should be based on clinical considerations. Of course, the individual should no longer be infectious. If an individual is noticing an improvement in symptoms, as many individuals will, a formal evaluation may not be required. However, if an individual’s recovery has plateaued, then a neuropsychological evaluation, or at least a screening, may be warranted.

Given the wide range of symptoms experienced, I think a multidisciplinary care approach is best, which is why I am very excited and honored to be part of the multidisciplinary team of the Saint Barnabas Medical Center/RWJBarnabas Health Medical Group’s Post-COVID CARE Program (https://www.rwjbh.org/saint-barnabas-medical-center/patients-visitors/what-you-need-to-know-about-covid-19/post-covid-care-program/ The program is open to individuals who are more than 4 weeks from their diagnosis and are still experiencing lingering symptoms.


Q: What does the evaluation of “brain fog” symptoms entail?


All of my evaluations, whether for COVID-related cognitive changes, neurodegenerative diseases, movement disorders, epilepsy, or traumatic brain injury, involve the same components.


First, I review all records that are made available to me by either the patient and/or their referring physician. Next, I conduct a thorough interview with the patient, preferably with a family member or friend present, to get a good understanding of the noted changes that brought them in to see me. I also want to understand the functional impact of those changes — that is, how have these changes affected their daily functioning, if at all? It is also important to get a complete history, including an educational and occupational history, medical and psychiatric history, current medications, recent surgeries, recent diagnostic test results, and a psychosocial history, including any recent stressors, and use of substances or alcohol.

It is important for me to take into consideration any factors that can affect one’s thinking, which is essentially everything. The next step would be to conduct standardized testing objectively assessing one’s cognitive and emotional functioning, including attention/concentration, information processing speed, motor functioning, language and visual abilities, and executive functions, along with the presence of psychological distress.


The final component is a feedback session, during which I review the findings and recommendations of the evaluation. In some situations, such as COVID-19 or concussion/traumatic brain injury, serial testing may be indicated to objectively monitor one’s recovery and address persisting issues.


Q: What self-care strategies and medical interventions, if any, are effective in reducing or resolving the symptoms of “brain fog?”

First, my recommendations for general brain/cognitive health apply here. These include:

  • regular physical activity, mental stimulation, and social engagement (as much as is possible in a safe manner at this time);
  • following a healthy diet, such as the Mediterranean or MIND diet;
  • healthy/good sleep hygiene; and
  • management of cardiovascular and cerebrovascular risk factors. A healthy heart equates to a healthy brain.


Not only do these recommendations facilitate cognitive and brain health, but they are good for your mood, as well.


Second, as individuals are recovering from infection, I recommend a gradual return to activity and the use of compensatory strategies to reduce the functional impact of their cognitive symptoms, especially in more severe cases. This is where a neuropsychological evaluation can be most helpful, as the results will inform treatment strategies. Getting back to activity is important, for recovery, mood, and quality of life, so my goal is to assist all of my patients in doing so.


Third, and perhaps most important, is to ensure that underlying psychological distress, regardless of its severity, is addressed, as this can contribute to poor outcomes. In some cases, cognitive remediation may be appropriate, particularly if indicated by the results of a neuropsychological evaluation. If there is pronounced psychological distress, psychotherapy/counseling or psychiatric treatment may be warranted.


When I meet with patients, I try to get an understanding of their thoughts regarding specific recommendations, including barriers that may interfere with their ability or willingness to carry out the recommendations. For instance, some individuals are extremely hesitant to start psychopharmacotherapy, such as treatment with an antidepressant medication, so in these cases, I will focus more on helping them establish psychological care with specific goals in mind.


Q. Looking beyond COVID-19 for a moment, how can older adults experiencing memory problems or related issues distinguish between what reflects the normal course of aging and what warrants medical evaluation?


That is a question that neuropsychologists deal with on a daily basis, and one that we sometimes struggle with, regardless of the reason for referral. How do we know if the observed neurocognitive weaknesses represent an actual change?To address this question, during the evaluation, we are able to make comparisons to a representative population sample that accounts for an individual’s age, education, and other relevant demographic variables. We also make interpretations of performances within an individual, and can estimate an individual’s premorbid or previous level of functioning. So neuropsychological evaluations can be quite sensitive in determining whether an actual change in an individual’s functioning occurred.


Our evaluations are really one of the only true methods of assessing and characterizing an individual’s level of functioning. A neuropsychological evaluation can reveal cognitive changes in conditions, such as concussions, where all other tests, including neuroimaging, are otherwise negative or unremarkable. Therefore, my recommendation for patients and family members is, if there are concerns about cognitive or behavioral changes, discuss these concerns with your primary care physician and/or neurologist, who will then determine if additional tests, including a neuropsychological consultation, is warranted. It cannot hurt to bring it up.


Q. What treatment strategies are you employing for people experiencing cognitive issues?


There are several approaches to managing cognitive changes, with the approach selected for a specific individual based on the nature and degree of impairment. Of course, it is most important to identify and address the underlying etiology of cognitive symptoms, as some conditions, if treated, may result in cognitive improvements. For instance, if there is an underlying nutritional deficiency or endocrine/ metabolic condition, treating that cause should, theoretically, result in an improvement in one’s thinking.


There also are various medications that can be used to enhance cognition or slow down cognitive decline, depending on the underlying condition. For instance, acetylcholinesterase inhibitors can be used in certain neurodegenerative diseases, and stimulants may be used in attention-based disorders or conditions where fatigue is a prominent feature.

Cognitive remediation is also a form of treatment that many individuals will benefit from, whether they have experienced a stroke, traumatic brain injury, or are even in the early stages of a neurodegenerative disease process. Treatment focuses on the development and implementation of compensatory strategies to increase one’s daily functioning, using the results of a neuropsychological evaluation to inform treatment.


There also are many computerized programs and numerous supplements purporting to support brain/cognitive health. All I can really say about those at this point is that there is not much convincing scientific support for these programs or supplements improving cognitive function. I believe caution is warranted with regard to these approaches.


Q. What steps can all people take to preserve or enhance their cognitive function across the lifespan?



Prevention is the best line of defense, and the best approach to prevention is a healthy lifestyle. As I mentioned earlier, regular physical activity, mental stimulation, and social engagement are key, as is good nutrition, adequate sleep, and maintaining cardiac health.


For mental stimulation, I encourage my patients not only to read, but also to learn something new, such as a new language or instrument, especially if this is something that they have been wanting to do.


We all can benefit from increasing our level of physical activity, which for some of us may consist of walking 20-30 minutes a day, three days per week. This is all beneficial for brain health.


There is also a newer book that I have been recommending to patients that incorporates scientifically supported strategies for maintaining cognitive/brain health. It is written by Dr. Michelle Braun, and it is called “High-Octane Brain: 5 Science-Based Steps to Sharpen Your Memory and Reduce Your Risk of Alzheimer’s.”


Dr. De Marco obtained his doctorate in clinical psychology from Yeshiva University, Ferkauf Graduate School of Psychology, and is board-certified in clinical neuropsychology through the American Board of Professional Psychology (ABPP).

He completed his predoctoral internship at the Coatesville VA Medical Center and then went on to complete a two-year postdoctoral fellowship in neuropsychology at the University of Virginia, where he served as chief fellow. Dr. De Marco stayed on faculty at the University of Virginia from 2012 to 2016 before returning to New Jersey. He then established the Neuropsychology Service within St. Luke’s University Health Network’s Center for Neuroscience, where he served as director of neuropsychology and adjunct clinical assistant professor within the Department of Neurology of the Lewis Katz School of Medicine, Temple University, until joining IGEA Brain, Spine & Orthopedics in 2018.


At IGEA, Dr. DeMarco practices with several board-certified neurosurgeons, a board-certified neurologist, a board-certified orthopedic surgeon, and other clinicians. With offices in Paramus, Union, Florham Park, Hazlet, North Brunswick, and New York City, IGEA offers comprehensive, multi-disciplinary care to patients experiencing a wide variety of neurological and musculoskeletal conditions and complaints.


To schedule an appointment with Dr. DeMarco or one of the practice’s other clinicians, or to learn more about IGEA, call 866-467-1770.


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