PEM induced only by sensory/cognitive exertion - what does it indicate about the pathophysiology of ME?

yes its interesting isnt it. I wonder if it's a severity thing? Not saying you're mildly affected Tigerlilea just saying about myself...
When i was 'mildly' affected at the very beginning (i say mild as opposed to mainly house/bedbound as i am now, not suggesting anyone who is considered mild is only sufffering mildly!) but at that stage I didnt have any kind of sensory issues, i was in denial that i was even ill, & with PEM being delayed my symptoms made no sense at all.
But i pretty sure I didnt have PEM triggered by cognitive stuff on it's own. It was only when i went rapidly downhill & became severe that i started to have sensory issues & cognitive induced PEM.

I do wonder though if the reason I think i didnt have it when milder is that it was difficult to ever do enough cognitive sensory exertion on it's own (appropriate to the much looser limits of being mild - i mean then i could have walked maybe a mile, I did a full day's work - unable to do anything else & often off sick for a couple wks at a time with what dr called 'a virus'... but i did work full time then. God it was hard.
But there would have been no instance of doing enough purely cognitive exertion - which, appropriate to my then level of severity would have been lying down reading for a couple of days straight - to be able to notice it giving me PEM. Because there was always need to be doing something physical long before that - getting a meal for example. So i'm not sure how i ever would have tested whether cog. exert. alone caused it or not.

To further explain what i mean... For example in overly simplistic physical terms... if you had to walk 2miles before PEM onset, but only ever got the opportunity to walk 1, you'd never find out that walking 2 triggered PEM. I never had cause/opportunity to discover if cognitve activity alone would have caused PEM when i was mild because i never did enough of it on it's own.

Just ruminating.

 

This is a good point, and also raises the question of whether thresholds for physical and cognitive exertion can be different.

Most days I probably can't do enough cognitive activity to trigger PEM because of attention deficits, but I can also hyper-focus. When I've really dived into something, I'll go anything up to 15 hours without eating because I'm so engrossed that I've forgotten. I've can do this for day after day, apparently without PEM.

It's possible there's a cognitive threshold that I haven't reached, or that the symptoms of cognitive PEM are so different that I don't recognise them, or that a raised heart and respiratory rate are necessary for me to get PEM. I get it easily from conversation, because this probably affects my heart and respiratory rate more than, say, having a shower – I laugh a lot, am physically expressive, and because I spend a lot of my time alone, I can get so over-stimulated that I don't control my breathing properly when talking.

I wonder if people who're severely affected might get the same significant increases in cardiovascular activity from simply sitting up, or becoming emotionally engaged through cognitive activity (e.g., reading something moving or funny)?

 

I think this may well be true for some but is a dangerous assumption for others.

Both cognitive exertion and sensory stimulus can trigger worse PEM for me with a longer recovery period than physical exertion, depending on the physical exertion of course.

Although PEM from both physical and mental exertion and sensory issues ate very similar, they are not the same. I find it much harder to cope with cognitive PEM & the complete loss of function it causes.

 

My experience is the opposite.

Initially cognitive issues caused me as much trouble as pain.

By the time I was diagnosed I was described as having moderate ME though I was still working. Ti a certain extent I could arrange my own schedule and it was possible for me to work from home.

Purely cognitive exertion (though I was upright at the time) definitely caused me problems.

One of the reasons, even in the early stages, that I worked from home as often as I could was I couldn't hear myself think in an office. I was okay in an environmental with background machinery noise but not phones ringing, printers going and other people's voices.

Sensory issues with stimuli that previously didn't bother me was a problem I experienced very early on. I suffered migraines for many years but this was a different thing.

 

I believe they can.

In a relatively good phase I can go for a walk with IM and be fine. We'll chat quietly as we go.

Doing the same walk with other family members, even if we split into groups due to narrow paths, is a much bigger cognitive load and will exact a higher payback despite it not being physically more taxing.

 

Exactly. My brain actually shuts down when my heart races and breathing increases. I have to stop talking in order to preserve my physical energy so that I can continue the walk.

 

Laughter ups PEM levels significantly for me. Laughter is a very physical activity, I've found to my cost.

I used to go on some retreats and we used to have a really good laugh, sometimes I'd be in tears.

The following day, or the day after, I'd feel.like I'd been beaten about the torso with a baseball bat. It would physically hurt to try to raise my arms, especially upper arms away from my sides. I'd be as weak as a kitten.

 

yes, the signal for me to lie down if i'm sitting up or standing & trying to think/speak, is my cognitive function just disappears and will not appear again until i am supine

 

Same. I do get prolonged (several days) cognitive fatigue (and headache worsening) from cognitive activity, but I don't get PEM related muscle issues or flu symptoms from it, whereas I do get those symptoms from physical stressors.
For me, sensory sensitivity (and OI) result from PEM, rather than the other way around.

Note that lying in bed in funny positions while reading, or sitting in a car or on a plane in the same position for hours can be a physical stressor... Prolonged stiffness from sitting in a car for 2 hours straight is not PEM from cognitive activity.

Nonetheless, there are potential common factors - impaired capillary blood flow in the muscles or brain and prolonged "central fatigue" (which is due to lower excitability of the muscle cortex, which is turn triggered by feedback of peripheral afferents).

 

As most of you know, I have no medical knowledge, so this is just my own thought from an engineer's perspective.

The one common factor I would have thought is energy demand. When we are looking, listening, etc, there is considerable signal processing involved, which is pretty intensive. The very act of thinking is pretty demanding also I believe.

So although this is a medically uninformed comment, to me at a very top-level view, it seems to tie in well with the usual ME/CFS problem of being unable to supply energy at the rate it is needed.

 

I used to get terrible sensory overload when I was first ill but these days (12 years on) it’s not so bad. It had been helped immeasurably by the gabapentin I was prescribed to help with sleep years ago, which given gabapentin was originally developed as an anti-epileptic drug makes some sense to me (not that I understand the mechanisms of either, more on the basic level of understanding that a brain affecting drug has helped my affected brain!).

But what I find interesting (in a horrible, I-wish-you-didn’t-have-to-cope-with-this-too kind of way ) is how closely my daughter’s symptoms mirror my own. Her sensory overload is way worse than mine ever was, she wears sunglasses all the time, ear plugs or ear defenders too (even in her own home on bad days and she lives alone), can’t cope with car journeys of more than about ten minutes without feeling nauseous and overwhelmed by the visual input and the noise (and she had never had travel sickness previously), and noise overload like people talking or traffic or even the sound of the waves when we’re at the beach reduces her to tears of distress and exhaustion. Airport security lines are hell for her, much worse than for me, and we have to get her taken through with assistance because she becomes so ill and distressed at the noise and light and movement. Busy stations, public places like pubs and shops are really exhausting and challenging for her to cope with and she can take days to recover from a single outing. Cognitive load exhausts her, especially talking, and the neuro-fatigue (apparently this is the correct term for it given its cause) can be crippling for her. Yet she doesn’t have ME, she has a brain injury.

 

So sorry to hear this about your daughter @Blueskytoo.

 

In my own case I don't think it's simply the brain prioritising one task over another, although I daresay there may be times when it does. It isn't about OI problems and being supine either, although at times they are a factor.

This morning, for example, I needed to sort a problem out on my current account with the bank. It's a fairly new app based account we switched to as our old joint, household account closed recently.

I was lying supported in bed, I had to call customer services and they asked me to go through various steps in the app while they put me on hold. The problem was even with the volume turned right down I could still hear the chirpy "on hold" music. I made a complete hash of what I was supposed to be doing and got myself into a right muddle.

In the end the nice customer service chap and IM had to take over and sort it out and the bank have offered to put a note on their systems that I have sensory difficulties.

Of course, now the "dee-dee-dee-de-dah-dah" sound has stopped I have realised that all I had to do was put the bank on hold while they had me on hold & that would have stopped the racket. While I could hear it, I couldn't think to do that.

It's taken me a good hour to try to get my brain to settle down and I doubt I'll be safe to use anything more challenging than cutlery - certainly not sharp kitchen knives or the like- for at least the rest of the day.

Typing this is taking a monumental effort - way more than it normally would.

Edit - typos

 

Bless you, Barry, thank you. She’s had a rough few years what with one thing and another, and she has some potentially serious health issues to live with on top of the brain injury, but she’s living independently now and is managing to work two days a week at a local stable whose owner is also her best friend. She’s a horse worshipper and always has been, so this has been the making of her. She’s doing brilliantly, really. When I talk about her symptoms it sounds awful and desolate, and she is and always will be disabled by them, but she has learned to cope with them and minimise the stresses on herself, just like all of us, and she has a good and fulfilling life that she’s living with gusto and appreciation. You honestly wouldn’t know there was a thing wrong on meeting her, it’s only after talking with for a while you start to notice she doesn’t always use quite the right word or has to ask you to explain something or repeat it. But she’s upfront with people about her issues and makes a joke of them a lot of the time to put people at their ease with her. She’s amazing. I’m so proud of her.

 

IM just discovered that I appear to have broken the banking app.

He just got off the phone from them and although our account is fine, there's a mismatch between the information displayed by the app on my phone and what the bank sees. IM's phone tallies with mine.

The bank have had to refer it to tech support. The app isn't new, it's been around for over a year so if it was a bug you'd think it would have been found already. Then I came along.

A good morning's work on my behalf I think.

 

I could have written that myself. I cannot do anything, any. thing. while music playing/someother "background" sound like neighbours talking etc. I've actually made similar cock ups & got myself in financial difficulty because of mistakes made while attampting to deal with bank stuff while there was sensory input going on in background.

For me it all amounts to the same thing, if it's able to do anything at all, the system cannot do more than one thing at once.... if i'm standing up (or during PEM if i'm just sitting up), then i cannot do congitive things like thinking or speaking, if there is sensory input going on then i cannot do thinking or speaking either. There simply isnt enough juice to go round to all those functions.

So i guess it's not really the brain 'prioritising' as such, but having to devote all energy resources to those activites it doesnt have a 'choice' about... ie if the body is upright then channelling the energy away from muscles & into thinking, would lead to bodily collapse & possible injury, & if there is music playing/bright lights flashing etc it has no choice but to process that, leaving nothing left for thinking.

 

Apart from my own inability to think straight and getting confused this morning's exercise has highlighted an angle I hadn't thought of before.

When in cognitive difficulties I must behave unpredictably - I don't mean in an an emotional, might lash out kind of way, though I can become annoyed very, very quickly when I'm struggling.

A relative of mine writes and troubleshoots banking interfaces. from what they've told me in the past, when software interfaces or apps like this are tested they'll try to test them based on selections people are likely to make and in what order. They'll deliberately set out to do things in the wrong order to see how the software responds.

This is fed back to development to make the software as user friendly & robust as possible.

Whatever I did must have been quite unpredictable, going well beyond simple lack of familiarity and lack of intuition on what to do next. Quite scary when these apps are designed to be used by technodummies.

This is something I make sure to highlight when filling in my ESA form as I cannot reliably follow safety instructions such as going to a designated fire assembly point, using a fire extinguisher, operating an escape lever etc - even when clear instructions are available.

 

I'm actually quite amazed how members here can write long articulate posts. I can not write more than 2 small paragraphs.

Question for those with cognitive PEM or cognitive impairment. Do you have a sore head/forehead when you are mentally drained? I can recover much quicker from cognitive fatigue than I can from physical exhaustion.

 

I have a headache in the upper front of my head 100% of the time, but it is deeper, I wouldn't describe it as a sore forehead (front of head above eyes) at all.

This pain gets much worse when mentally drained. It is quite likely this is related to some sort of blood flow or cerebral perfusion issue.

 

@Mij I have a weird sensation in the forhead/front of my face, not with bad pain exactly - more like intense discomfort, with a weird sort of 'thick' or numb feeling. Like i've been hit in the nose/upper face with a football but without the major pain you'd have if that happened. IT's a more dull ache & Like someone stuffed treacle, or liquid cement up my nose & into my head, so that all thoughts have to trudge through it. It is very like being stoned on weed. Very like that, despite it being about 30yrs since i had that experience it is soooo similar to what i remeber

I actually often write more when i'm goofy, because my ability to summarise dissapears, i cant seem to explain in a direct/succinct way at all, so i ramble a lot more i think.