S4:Ep17 – What is Brain Fog?


Voice-over: Welcome to Spotlight on Migraine hosted by the Association of Migraine Disorders. Join us for fresh perspectives by medical experts and advocates as we explore the spectrum of migraine and dig deeper into this complex disease. This episode is brought to you, in part, by our generous sponsors, CHAMP and Amgen.

Stay tuned as Dr. Courtney White explains what brain fog is, why it occurs, and what can be done to manage this bothersome symptom that affects so many people with migraine.

Dr. Courtney White: So today I will be talking about brain fog, a concept involved in migraine that doesn’t get talked about enough, in my opinion. So for as long as we’ve been talking about migraine, we’ve been talking about brain fog. We’ve been talking about that there’s so much torpor or lethargy, heaviness of the head, anxiety, and ennui or listlessness. We’ve been talking about alienation of the mind when we talk about migraine. And we talk about impairment of memory, confusion, incoordination of ideas, confusion, inability to collect our thoughts, feeling silly, losing senses.

Brain fog being associated with migraine is not a new concept. So we’re going to talk a bit about brain fog – what is it, some of the common symptoms, why does it happen, and what can we do about it. So first, what is brain fog? Well brain fog is a myriad of symptoms. It can include language problems, difficulties with speech or reading, involves irritability, mood changes, fatigue, tiredness, problem with concentration usually decreased concentration, feeling a little bit slower in getting things done.

Overall, it leads to problems in what’s called executive dysfunction, being able to carry out higher order activities like cleaning something, grocery shopping, taking care of your children. So often does that occur? As we just talked about, you know, there’s different phases of migraine, and it’s often in the headache phase that we experience these, but it’s not always just when the headache is occurring. It can happen up to 25 to 36 hours before the headache stage, and cognitive symptoms or brain fog can peak about 12 hours before the onset of the migraine attack when you experience the headache part.

You also see it in the postdrome up to 12 to 25 hours and is one of the more common symptoms at the end of the headache phase of a migraine attack. How common is it? Well looking at studies of people who speak about the symptoms they have besides the headache during their migraine attack, we see that cognitive symptoms occur in anywhere from about two-thirds to almost all people who have migraine at about the same frequency as nausea, sensitivity to light, sensitivity to sound, and feeling like their symptoms worsen with physical effort.

These other symptoms – here on the bottom in the light blue – are part of the diagnostic criteria of migraine. The brain fog happens just as frequently, so therefore it’s an integral part of migraine disease. What parts are affected? Well we actually have done testing, objective cognitive tests, on people during their migraine attacks, and we saw objective impairment during an attack in processing speed, attention, both verbal and nonverbal memory. Some of the verbal skills being able to speak, executive function, which we talked about, carrying higher order tasks, and visual motor skills like this here. This diagram is a Trails Test where you have to kind of follow the dots in a pattern requiring some higher order thinking. During an attack, this is a lot harder to do.

We find that frequency and duration, when increased, is correlated with worse cognitive function. So those who have chronic migraine tend to have worse cognitive function. And in folks with chronic migraine, even if they’re having low symptom or no symptoms compared to nonmigraine controls, sometimes will have issues with cognitive functioning. So we know it exists. But the question is why?

So we’ve done PET scans, functional MRI looking at the parts of the brain that are activated during different parts of the migraine attack. And we find that 3 areas, in particular, are more affected than others, including the frontal lobe, which is involved in things like paying attention, making decisions, higher order functions, that executive function we talked about. The thalamus and hypothalamus are involved in things such as processing speed, as well as wakefulness, arousal, and dysfunction in this area can lead to the things like fatigue. And finally, our temporal lobe, another part of the brain that is involved both in memory and language. So when we see that there’s alterations in brain functioning at this time, it explains the symptoms that we see.

Not just the kind of higher-level imaging studies that are used more in research but also on a regular MRI we see changes in the brain in people with migraine. We often see what are called migraine spots, and this is due to changes in cerebrovascular or blood vessel in the brain dysfunction, and it actually changes the brain over time that we can see. Good news though – there’s no correlation between the number of migraine spots and cognitive function. And those with migraine even though they have severe cognitive symptoms during migraine attacks – sometimes in between – looking at people over long term, there seems to be no correlation between having migraine, having more lesions on your brain, and progression to dementia later on.

So I think the most important thing we all want to know is what can we do about it? How do we solve this issue? So, I looked for studies on evidence-based treatments specifically for brain fog associated with migraine. I asked out in social media for other people who had any idea if there’s anything we have. Unfortunately, no studies could be found. So at this point, it’s more based on expert opinion. So a couple of things that can be done to help with treating migraine is first, let’s rule out that this is…let’s make sure there’s not just migraine. If there’s something like increased cerebrospinal fluid pressure or decreased, treating those symptoms can help with some of your cognitive fog. If it is a secondary headache disorder such as giant cell arteritis, temporal arteritis, treating with steroids can help with some of the cognitive issues.

The second, of course, is treating the underlying migraine disease, which is easier said than done for sure. But as we continue to treat migraine and look for those improvements in cognitive function, let’s also manage comorbidities. Things like depression and anxiety can also affect cognitive function. And there are several medications that have been well-known to have cognitive side effects. So we have to figure out a balance – treating migraine disease without using medications that can worsen the cognitive fog, the brain fog if that is a more bothersome symptom for the patient.

Some studies that we can do for our patients that can help us really better define where your challenges are, where your strengths are is neuropsychological testing, and it really kind of maps out to make a more personalized treatment plan rather than some of these general recommendations that I’ve already made. And finally, cognitive rehabilitation has been helpful for other cognitive dysfunction. And what cognitive rehab is is really looking at these cognitive processes, improving on the areas that you do have strength, and also coming up with compensatory mechanisms in situations where you are struggling a little bit more. Learning how to use accessibility devices, making checklists, using phone alarms, things like that to help you out.

So in summary, we know brain fog is real. We know that the cognitive symptoms of a migraine attack happen before, during, and after the headache phase, and it can happen in between attacks. We know why it’s happening because of the nerve dysfunction that is migraine disease. It affects those certain parts of the brain at different times leading to the symptoms specific for it. And in terms of what we can do about it, well at this point, treating the underlying migraine disease is the best option but also support through things like assistive devices, compensatory mechanisms, and cognitive rehabilitation. So thank you very much for your time.

Voice-over: Thank you for tuning into Spotlight on Migraine. For more information on migraine disease, please visit MigraineDisorders.org.


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