I experience what I describe as muscle weakness but I have never been sure if this is connected with muscle strength. It is one of my main symptoms along with muscle pain and general discomfort of the muscles.
First thing in the morning when my feet hit the floor and I rise; my legs are 'jelly-like' in feeling and when I walk at times I describe myself as having 'jelly-legs'. But I am able to walk. So I am not sure what's happening.
Muscle weakness is termed in several criteria and primers I noticed on a quick Google; but I couldn't find any published papers that coined the term and linked it to ME. So could it be a descriptor but not a recognised medical distinction?
Myalgia is of course firmly linked to ME but is muscle weakness? Or is weakness a patient-descriptor i.e. something we use as a term to describe the feeling?
I do experience difficulty in supporting weights at random times and with random weights as has been said I think above; raising a mug of tea can be an issue or supporting a book. But I can't connect these with specific times or for example, following some exertion or activity. However, it is usual to experience this more when I am trying to rest so perhaps it is - as seems to be intimated by the Primer etc. - an example of PEM.
When enduring 'muscle strength tests' I have always been found to be normal. Or at least in these very basic tests nothing abnormal was flagged that warranted further investigation.
The DHSS Primer states:
Fatigue and Post-exertional Malaise
Patients with ME/CFS experience abnormal fatigue that is both more intense and qualitatively different from normal tiredness. The fatigue in ME/CFS may take several different forms: post-exertional fatigue (abnormal exhaustion or muscle weakness following minor physical activity), persistent flu-like feelings, brain fog (mental exhaustion from everyday cognitive effort), and wired fatigue (feeling over-stimulated when very tired).
The type of fatigue that is a core feature of ME/CFS is post-exertional malaise (PEM). PEM is the exacerbation of fatigue and other symptoms (e.g., cognitive difficulties, sore throat, insomnia) following minimal physical or mental activity that can persist for hours, days or even weeks. PEM may be related to abnormal energy metabolism...
The Overview to the 2003 Canadian Criteria states (note this falls under Neurological/Cognitive and not as above):
5. Neurological/Cognitive Manifestations:
Two or more of the following difficulties should be present:
confusion, impairment of concentration and short-term memory consolidation, disorientation, difficulty with information processing, categorizing and word retrieval, and perceptual and sensory disturbances – e.g. spatial instability and disorientation and inability to focus vision.
Ataxia, muscle weakness and fasciculations are common. There may be overload1 phenomena: cognitive, sensory – e.g. photophobia and hypersensitivity to noise - and/or emotional overload, which may lead to “crash”2 periods and/or anxiety.
I am sure muscle weakness, along with soreness, and pain, and spasms; appear in other criteria but I couldn't quickly locate them.
In the NICE Guideline - the
Full Guideline from 2007 - Patient Representative 2 (page 103) provides the following recollection:
...Within months it was clear that I might have CFS/ME, and I knew of other people who had experienced similar problems. There was no formal diagnosis made, just an acceptance by the GP and myself that it was ME. Support came from another person in a similar position and from the National ME organisations and their magazines. Obtaining information was not as easy in 1991 as it is now.
The result was that there was much stress in having many of the strange symptoms that people with CFS/ME experience, but without knowing that these were commonly experienced due to the illness. For example, twitching muscles, muscle weakness, and pains that travelled around my head and body over the
course of a few days, and many more...
NICE (page 148) also says that the (I presume CDC) 2002 criteria includes the phrase :
Unexplained generalised muscle weakness
as part of it's symptoms checklist.
NICE in their Guideline for diagnosis do not include 'muscle weakness' but then again they only include (page 34):
muscle and/or joint pain that is multi-site and without evidence of inflammation
However I wonder if:
general malaise or ‘flu-like’ symptoms
might also be considered by the layman and doctors alike to include reference to 'muscle weakness'?
What I suppose I am getting at is, is Muscle Weakness a defining symptom of ME or part of something else that is considered defining? And is 'muscle weakness' a patient defined term but not medically defined?
When I was infected with a virus, or when I have a cold, even the flu, or when like now I am feeling exhausted, I generally feel weak. But there is a definite feeling of muscle weakness too. And often this is persistent. But whether it is a feeling and part of something else that is more generally defined - like PEM - I really couldn't say.
Muscle problems are for me a defining part of ME, have always been and should always be considered to be so. I think weakness is part of the whole