How to understand it: Brain fog 2024 McWhirter

[Andy]

Abstract

‘Brain fog’ is a term that patients use increasingly frequently in the neurology clinic. We may think that we know what patients are talking about but at least some of the time we are likely to be getting it wrong. Patients use the term ‘brain fog’ to describe a wide range of subjective phenomena and symptoms. This paper suggests useful lines of questioning, and discusses the clinical correlates of a range of common ‘brain fog’ experiences.

Paywall, https://pn.bmj.com/content/early/2024/09/19/pn-2024-004112

 

[Hoopoe]

Similar to how a muscle can feel unpleasantly tired and less capacle of doing work, the ability to think can feel impaired, be accompanied by unpleasant sensations of effort and unwellness, with difficulty forming clear thoughts, finding words and recalling things. And I think that sensation of impairment and discomfort is what people refer to as brain fog.

 

[duncan]

"subjective phenomena"??

Which brain fog symptoms would be excluded from "symptoms"?

And why is she acting like the use of brain fog is new, and is primarily a patient thing? In my experience I see doctors using it more, far more than I. I think it's dated and uninformed and demeaning - and almost a red flag that the clinician or researcher is at best condescending, or worse, out of touch.

Fog dissipates, clears up with the sun.

What we have does not.

 

[Arnie Pye]

One thing I find odd about "brain fog" is how doctors seem determined to change the name of it, just like they seemed to be determined to change the name of "Long Covid" for a while. I think they may have lost the battle on Long Covid though.

I came across the name "foggy brain" recently and thought that sounded really absurd. I know I've read other names but my own brain fog prevents me from remembering them right now.

 

[Nightsong]

This isn't as bad as I thought it might be although it has a rather FNDish perspective. The phrase "brain fog" is certainly far too broad a term to be of clinical value and to elucidate whether attentional, affective, higher cognitive etc symptoms are meant by the term is absolutely necessary. Not sure about this:

Patients with functional cognitive symptoms complain bitterly of these sorts of experiences, which they interpret as evidence of brain failure despite continuing to demonstrate intact memory and concentration skills at times. Others have discussed the possibility of brain fog as functional cognitive disorder. In our experience, though, brain fog is only sometimes an isolated cognitive experience. Only in cases where the isolated cognitive nature of symptoms and extent of associated disability is significant would a diagnosis of functional cognitive disorder be considered. We should also bear in mind that patients with many symptoms are vulnerable to accruing many diagnoses, which can cause a loss of focus in treating clinicians

It would probably be best if the use of the term was limited to what was previously called pseudodementia.

Very little evidence for this, I think:

More often, inattention is a transdiagnostic ‘side effect’ of the burden of symptoms. We can hypothesise that symptoms (of any cause) cause attention to be directed towards the body and towards managing the symptoms. Hypervigilance—again, common across a range of illnesses—primes us to ‘scan for threat’ in the body and surroundings. Inattentive lapses result from both processes.

Strategies for optimising routines and environment in order to promote and protect attention and reduce hypervigilance can be extremely valuable in patients with inattentive brain fog, many of whom place high levels of demand on their own function.

The conclusion:

‘Brain fog’ is a term that has arisen from the lay population and has proliferated via media and social media channels. Vividly evocative, brain fog can be an impediment to forward progress, a clouding of previous sharpness, or a feeling that descends and lifts at different times. Crucially, brain fog does not align with a single symptom, disease, illness or syndrome, but is a term validly used to describe a very wide range of subjective experiences.

We should perhaps acknowledge the restrictive nature of the clinical vocabulary that we as physicians use to describe subjective experiences of cognitive, affective, arousal, even somatic symptoms. The core point of this summary is that in order to understand brain fog, we need to ask more questions. Engaging with patients to clarify what they mean by brain fog will help us to understand what the problem is and how we can help. In polysymptomatic patients, this discourse aids therapeutic alliance but also surprisingly frequently reveals straightforward targets for treatment.

The "key points":

► Brain fog is a vivid image used to describe a broad range of subjective experiences; always ask for a description of the brain fog experience.
► Evidence points to brain fog being a transdiagnostic group of symptoms rather than indicating any particular disease.
► Curiosity about brain fog may direct us towards specific treatment targets, such as migraine, dissociation, mood disorder or sleep disorder.
► ‘Cognitive’ brain fog correlates poorly with objective cognitive impairment; but may be prominent in functional cognitive disorders or in illnesses with a large symptom burden.

 

[Andy]

although it has a rather FNDish perspective

Not surprising,

"Research summary
Laura McWhirter's research interests are in cognitive disorders, functional neurological disorders, and brain injury.

Current research interests
Dr McWhirter's current primary research project aims to describe various clinical phenotypes in Long COVID.

Past research interests
Somatosensory attention in functional neurological disorders, Foreign Accent Syndrome, transcranial magnetic stimulation, the history of physical treatments for functional neurological disorder."

https://www.ed.ac.uk/profile/dr-laura-mcwhirter

 

[Mij]

My sister has Hashimoto, her 'brain fog' is brought on by certain foods- mostly carbs.

 

[Eleanor]

‘Cognitive’ brain fog correlates poorly with objective cognitive impairment

... when you test for it using blunt instruments that don't properly identify it, and refuse to do any more specific testing on the grounds that it would 'medicalise' the situation. Then you can happily reassure yourself that the patients are wrong, you are right, and all is for the best in the best of all possible worlds.