Periodic Paralysis, myotonia, channelopathy and ME

My experiences, which I’ve discussed at length on The Other Forum, have led me to read up a bit about Periodic Paralysis.

Reading more I feel like it might well have some biological connection to ME and/or POTS. The name is slightly misleading, it does involve symptoms other than paralysis which can include brainfog, phases of weakness and delayed reaction to exercise. They seem to have something like PEM though there are variations in how it expresses.

If you read this account, she could easily have been misdiagnosed with ME:

http://fightinghkpp.blogspot.co.uk/2012/05/the-battle-against-periodic-paralysis.html

I’ve definitely had very similar experiences, as well as more full on paralysis. Although my stamina is very limited, what most intrigues medics is my changing strength. I can have an abnormal neuro exam and EMG showing proximal weakness, then another day I can have a normal neuro exam. I can walk up and down stairs like a healthy, then an hour later not be able to walk a step.

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Periodic Paralysis is a very rare condition and it is properly ‘genetic’, involving specific mutations rather than a collection of genetic tendencies. It is to do with potassium/sodium/calcium channel problems.

I do wonder though if it is one of those conditions that is rarely diagnosed rather than genuinely so rare. Or it might not be so rare for us. In the same way that POTS goes from unlikely to 1/3 probable if you have ME, there might be some reason for comorbidity.

Also people with PP have told me they’ve noticed comorbidity of POTS, so that seems to be a thing (even if it only applies to the POTS&ME subgroup).

In terms of illustrating what I’m wondering:

Is there a small comorbidity like this?



Or do lots of us have a comorbidity that goes undiagnosed?


Or is PP properly separate but ME and POTS are more common so a likely misdiagnosis?

 

If you’re curious to find out more here’s a booklet about diagnosis: https://docs.google.com/open?id=0B-savOlQA6QCZjRjODdlMWYtM2M4NC00ODFlLWE4MDMtMGIyOWFmZjJiMmNi

A common misperception that doctors have is potassium levels are abnormally high or low (for the general population) during episodes. It isn’t necessarily that obvious, it’s about reacting badly to the change in your body. So someone with hypokalemic periodic paralysis may have technically ‘normal’ potassium levels both during episodes and out of them, but during an episode of paralysis (or other symptoms) their potassium will have dropped relative to when they are asymptomatic.

 

BTW this shouldn’t be under MS, I thought I was putting the thread under Neurological.

 

@Jenny TipsforME , my wife has PP, and I also see striking similarities between many of her symptoms and those of other PP patients with symptoms of pwME.

BTW, there is a special PP patient association through Periodic Paralysis International. My wife is part of it, and the info she gets is very helpful since there is a dearth of data on PP - just as there is with ME/CFS. It's an email chain, and it is heavily vetted, but if you are not familiar with it, it may be worth looking into it.

Yes, PP comes with payback for doing certain things, and also for consuming the wrong things. Indeed, part of the diagnostic process involves provoking an episode to discover whether a given patient is hypo or hyper.

And yes, this most certainly is a neurological topic.

 

Yes I remember. You were the one who introduced this to me.

That booklet is through Periodic Paralysis International.

Another line of speculation I have is do we have a similar mechanism going on without the genetic mutations? Eg could damage after a virus cause ion channelopathy?

 

There are autoimmune channelopathies. eg myotonia (a similar thing I’m looking into) can either be genetic or acquired on an autoimmune basis

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3151600/

 

There was another thread on PR and the idea of a sodium channelopathy came up briefly because of something to do with sodium...I think it had something to do with Davis?...I'm sorry, my memory...But like you I too have wondered if somehow at least a subset of pwME triggered a channelopathy. People have acquired channelopathies, so it's not a crazy idea. I suspect no one is looking: very few are looking at PP and very few are looking at ME/CFS, so the odds of someone seriously exploring this as an option likely are remote.

 

That’s the reason I started this thread @duncan my hunch is there’s something to be found here and no one is looking in the right place.

My PR thread was looking for personal answers, but with this thread I’d like to explore the general idea of a connection between periodic Paralysis, ME and POTS. I do think POTS is relevant here. I don’t have the expertise to work out why, but I don’t think the apparent comorbidity and sodium/potassium balance overlap is coincidental.

 

Most neurologists don't know anything about PP even though it falls within their domain. How many neurologists are competent about ME/CFS? The only "expert" I can think of that is a neurologist would be Natelson.

Even when it comes to POTS, most of us get referred to an electrophysiologist instead of a neurologist.

I agree with your premise, @Jenny TipsforME , but I wonder who would have the expertise to test?

I suppose it would be a pwME cohort examined by a PP expert, but if a channelopathy response cannot be provoked - what then? If PEM can be triggered, a sodium or potassium imbalance may not occur. But it would be cool to find out...

 

This is interesting to me as I have had a recurring pattern of what I would term 'mini strokes' or periodic ataxia when I overdo things.

It's not paralysis per se but it's always the same - my right foot starts sticking out, then the whole leg starts dragging, then both legs. I end up unable to do more than shuffle and only by concentrating, unable to lift my head think or speak. Usually a few hours in bed helps but on occasion it's taken weeks to get back to my 'normal'.

Presumably as an inherited disorder periodic paralysis (the symptom) is a lifetime pattern rather than acquired?

 

Yes I agree it would need to be that way around. An interesting thing would be if a PP expert could sort PP patients from pwme correctly (with and without looking at mutations).

 

@Marco , PP can be inherited or acquired, from what I understand. Symptoms can appear early in life or later, even when inherited. My wife was born with certain PP characteristics, but most of the more serious ones appeared after she was an adult.

Also, even though it is referred to as Periodic Paralysis, some (many?) sufferers never experience paralysis - just profound weakness (along with a bevy of other symptoms).

 

@Marco actually no it isn’t necessarily lifelong, though it’s unusual to get past your mid twenties without at least an episode of weakness (some people with the mutations never get full on paralysis, but they know because of family testing).

Interestingly advice is to not disregard weakness which was labelled CFS when thinking back to when it started.

 

Crossed over!

 

@Jenny TipsforME , there are not a whole lot of competent PP experts out there, and even less with any budget. Do you know when the last ATS research by the NIH was performed? YEARS ago.

But I agree - that's likely the way to go. That private email thing that Periodic Paralysis International provides touches on some of the few good specialists from time to time. Those patients are like us - they take research into their own hands as much as they can.

 

I’m not the first to think of this apparently

 

How are channelopathies examined?

It's always "crazy" what illnesses exist! Very interesting, in a way. Thanks for these infos.

 

I thought about a study which looked into channelopathies in ME. You found it

 

I only had "paralyses" two times, both in the right leg. I imagined it to be "exhaustion symptoms". I think there could be several reasons, and it's nothing like you report here.