Facets of ME: Cognitive Dysfunction

Welcome to our second Facets of ME! This is an educational feature in which we choose one aspect of ME to dive into and explore more in-depth once a month. Our goal is to keep it understandable while still providing a great overview and links to even more detailed information. 

The facet of ME that we are exploring this month is cognitive dysfunction, also known as cognitive impairment. Some might refer to it as brain fog. We see so much talk of this in our community. We also see a lot of misunderstanding of the severity and breadth of cognitive dysfunction, especially for those who have not experienced it. 

Cognitive dysfunction or cognitive impairment is a common symptom of ME/CFS and is used for diagnosis in most case definitions. Jaime Seltzer, #MEAction’s Director of Medical and Scientific Outreach shared: 
“Brain fog is a grab-bag of potential neurological symptoms that impair cognition. That can include issues with attention, memory, word-finding, spatial reasoning, even aphasia. These symptoms can vary in presentation and intensity, from being a minor irritation to making it impossible to carry out everyday tasks like reading or driving a car.”

See a thorough list of many forms of cognitive dysfunction on Mepedia.

It commonly occurs or worsens during post-exertional malaise (PEM), which is the hallmark symptom of ME discussed last month.  It can also result from orthostatic intolerance, a common issue in ME.  Many with Long COVID are dealing with cognitive impairment which makes sense with preliminary studies showing that nearly half of people with Long COVID meet the diagnostic criteria for ME. According to the survey of people with Long COVID by the Patient-Led Research Collaborative, “88.0% of the total respondents (3310) experienced cognitive dysfunction, memory loss, or both at similar rates across all age groups.” 

Lived Experience

What does it look like in everyday life? How does it affect quality of life and ability to carry out acts of daily living or the ability to work or participate in school? That varies from person to person and even possibly varies at different points in each person’s illness. Thank you for the amazing community feedback and participation when we asked for your help to describe this symptom. We know it will help people with ME feel seen and understood as well as help those new to the illness, whether through Long COVID or other means, come to understand a bit more about what it means to live with this symptom. We also hope it provides caregivers, medical providers, and allies a broader understanding of this critical symptom. 

The people experiencing it say it best. Here are some examples shared by our community: 

"It feels like part of my brain is missing and I miss it!"

"For me, it feels like part of my brain is missing. It's like it is completely overwhelmed with trying to cope with more than one tiny task at a time. I can talk to someone and understand them, but not if there is another noise at the same time. I can read something or follow slow instructions, but not if there is a distraction. I can type these words, but it takes Herculean concentration and I have to check through what I’ve written many times as I miss words out or can’t recall words that I want to use.”

“When this symptom is really bad and someone asks me to make a decision, even a small one like what to have for dinner, I just can’t do it… The effort to decide, the energy needed to choose, is just more than I’m capable of. I need a lot of time to make any kind of decision.”

“I put things in the wrong places, forget words, and don't know how to explain what it is I'm trying to say. I stare into space for hours because I am lost in my own empty head. I know what I should be doing, but I can't seem to send the message to my body to get it done.”

“I have not been able to read a book in full properly for years (I was a huge reader). Can't easily focus. My thinking process overloads easily, so I can no longer multi task normally. Can't think straight. Poor concentration and focus… I don't feel like my brain is firing on all cylinders. The processing of information is laboured.”

“When you’ve used an eftpos machine thousands of times to pay before but you get out your card and go completely blank. You suddenly don’t know what you’re doing, why you’re doing it or how to do it.”

“I can listen, talk, write, or read, but only one at a time and very slowly. It’s a feeling that cotton has filled your head. Frustrating as all get out. And scary. Very scary.”

“Sometimes like my thoughts and brain are running on delay from reality, like I'm in slow motion. Sometimes like there is a fuzzy cloud between reality and my brain. Sometimes it feels like there is something slowing my thinking down, like the gears are clogged up, like my brain is stuck in thick molasses… When the pain ramps up and thinking slows down, it's like my whole being is screaming to be left alone in quiet. When someone tries to talk to me when I'm like this I get irritable because it hurts to think, it hurts to process, and I need it to stop.”

“Ten years ago I was presenting to VPs of blue chip companies. Today, during conversations about basic household topics, I struggle to recall every fifth word or so. An activity like ordering takeaway on an app can cause me to crash - my brain can’t seem to cope with choosing dishes and then adding payment information. This literally drains all my day's energy.”

“I was doing a degree. My memory started to fail and I found I could not remember what was on the previous page. Then it became the previous paragraph. Finally I gave up when I found that I could not remember the start of the sentence.”

“I used to be able to get all the ingredients (milk, coffee) and boil a kettle, but then I couldn’t remember how to actually make one. I’d just stare at the coffee and milk and wonder why the kettle was boiling. I’d be so scared. Now I have several different methods of making coffee… So hopefully I remember at least one method.”

“I was unable to compare data or grasp instructions, no retention, there was a brain delay. Towards the end, the sensation was that my head was this huge ball the size of a tire; it pulsated in pain. The exhaustion was agonizing.”

“Cognitive dysfunction with my illness has been a decline. I have trouble remembering words, I stop while I’m speaking to try to remember what I wanted to say. It’s a “tip of the tongue” feeling, often… Short and long term memory issues, communication problems…It has been very difficult — as if I’m getting dementia at age 35.”

It is important to clarify in this lived experience section that  those with the most severe side of this symptom would not be able to send in their lived experience. They might not be online at all or it would only be in a very limited way. They are lying in their darkened room staring at their walls unable to read or watch tv or listen to a podcast to help pass the time. It can be agony to be lying in pain unable to do even the bare minimum to distract themselves. Jessica Taylor Bearman and Whitney Dafoe provide examples in their writings now that they are able to communicate more.


This can be an extremely debilitating symptom affecting work, school, and home life. We can do some things to mitigate it but it will probably always be present in some form. First and foremost, we can apply the overall message of #StopRestPace- avoid post-exertional malaise! Cognitive impairment during PEM worsens and we never know when that might become a new permanent symptom. 

Modern Technology

Technology available through smartphones, tablets, and smart watches provides handy ways to set alarms and reminders for important appointments and time to take medications as well as the little things we need to keep up with during the day. You can use calendars on your phone and set as many reminders as you need or you might keep a notes app to jot down thoughts you are afraid you will forget. Setting an alarm and then pushing snooze so it keeps reminding me every 5 minutes until a meeting begins is something I personally utilize.

Low Tech Solutions

Use planners, calendars, sticky notes. A notepad and pen always within easy reach can be a great tool. Prepping your medication for the day or week ahead of time so you can easily see what you did or did not take that day using a pill dispenser can help. 


This is an area where you can be a big help here to organize and remind as needed, working with what the person with ME desires, of course.

Limiting Sensory Stimulation

When trying to perform a cognitive task, it is especially important to limit other sensory stimulation. For example: using the simplified version of a website, focusing on one task at a time, limiting noise while concentrating, etc. You might also need to choose one version of sensory input over another. Perhaps you can listen to an audio book or the audio version of an article easier than reading it in print. It could also be the opposite for you. 

We can put some tools in place to help but it will always come back to limiting your exertion. Your body will not allow you to barrel through unscathed. You might need to greatly limit cognitive tasks because your body allows you no other choice. Pacing is very individualized but it applies to cognitive exertion just as it does to physical exertion. 

Please take a look at #MEAction’s pacing guide to help minimize PEM.

Our friends at  Bateman Horne Center have detailed information meant for medical providers that you can use when talking to yours. We have summarized so please follow the link for detailed information. 

General Principles of Supportive Management

1) Address all other conditions (complete a good medical work-up).  Rule out: anemia, thyroid, diabetes, sleep apnea, low Vit B12, polypharmacy, etc. 

2) “Pace.” Work with patient to recognize energy depletion to prevent symptom escalation. Focus on preventive activity management, and reduce overload.

3) Address the major aspects of illness: pain, sleep, mental health, orthostatic intolerance, and more. 

4) Address potential contributors to “brain fog” and cognitive slowing. Examples include medications, sleep disturbances, orthostatic intolerance, PEM, and more.

5) Medications that might help brain fog and cognitive impairment (please note these come with cautions, see Bateman Horne link for full info and talk to your medical provider)

Meidcations: Wellbutrin/bupropion, Stimulants – caution: can lead to a crash or PEM, ethylphenidate (Ritalin), Dexadrine (Adderall) – caution: can raise BP and HR, Newer drugs for daytime somnolence, Modafinil (Provigil) and armodafinil (Nuvigil) – caution: can disrupt sleep, 

Supplements (a few examples, not supported by strong evidence): Fish oil, omega 3 fatty acids, Phosphatidyl serine, Curcumin (from turmeric), B vitamins (B6, B9, B12) related to homocysteine metabolism, Vitamin E (tocopherol), Vitamin A, Vitamin C

6) Behavioral strategies for managing cognitive impairment: dampen other sensory input, use timers, schedule cognitive tests for your best time of day, etc. 


Neuropsychological testing is not necessary for diagnosis, but it can be used for disability claims and to observe some cognitive impairment such as: attention and processing speed and memory impairments. 

We are not going in depth on testing options but we wanted to point you in the right direction. We also caution to be aware of testing causing PEM especially in depth tests such as Wechsler IQ test. In this list, you can look under memory, executive functioning, intellectual functioning, etc:

Testing: https://www.commondataelements.ninds.nih.gov/Myalgic%20Encephalomyelitis/Chronic%20Fatigue%20Syndrome#pane-166

For more information on cognitive impairment in ME/CFS:

Artist Credits
@corywysz & @miss_diagnoses


4 thoughts on “Facets of ME: Cognitive Dysfunction”

  1. I have found that NAD, an antioxidant cell regenerator, treats my brain fog almost completely. My brain becomes like normal again. Furthermore, NAD is used with dementia patients to help memory and brain function. Also, NAD heals atypical cell growth in the body, thereby preventing disease. I am not affiliated with any NAD products and have nothing to gain by posting this.

  2. I have found all kinds of little things which help for me, as a mainstream novelist (I used to be a researcher in plasma physics at Princeton).

    I think most of what I do is different from most other writers, and I go on about various pieces on my blog, but without them I would never have completed and published the first book in my trilogy with an ME/CFS main character (of three) at 167K words after 15 years, and would not be almost finished with the second book (slightly longer) after only 7 more years.

    Between the brain fog and having zero energy, I occasionally wonder why I bother – but I really like writing fiction, these novels will be my legacy, and the reviews have been embarrassingly good. So this is what I’m doing with the life I have left.

    It is work.

    1. Thank you so much for this. I recently applied for benefits and was assessed as not displaying cognitive difficulties and being orientated . Assessment was at 9am in my own bedroom with no distractions. I have appealed and will use this email in my appeal. I am also applying for medical retirement and will save this for my assessments. I have forwarded to famiky and friends to helpnthem understand me. I am so grateful I could cry. Thank you.

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