From our former beloved moderator Joel
This was discussed extensively with a neurologist who started, and still heads, a neurological association in a large medical center in Houston. He went to Baylor College of Medicine, worked for several years at the Mayo, and serves on the AMA policy board. This is the 4th largest city in the country and his association sees a significant portion of the ALS cases that occur here every year.
As recorded by a patient.
First off, he saw lots of visible twitches throughout my body. No big deal, according to him. In fact, the only reason he gave me an EMG was because of my reflexes, which were slightly brisk. The twitches meant nothing to him.
I asked him to explain to me what an ALS twitch was like, and we ended up in a discussion of fascics and myokymia (I have both). This is coming from memory, so I'll try my best to tell it as I remember it.
In ALS, the nerves located in the small fibre of a muscle begin to lose their connection. As such, they begin a process of slight fasciculation, which is like a distress signal for another nerve to come to it's rescue and reinervate. ALS twitching starts out very fine, and pretty much invisible to the naked eye. However, since these affected muscle fibres are no longer working well, you tend to notice weakness and possibly slight atrophy before you ever notice twitching. The comment about ALS twitching not coming and going is very true, according to him. Once this muscle gets cut off, unless it reinervates, it continues to rhythmically (important, meaning steady and constant) send out these distress signals harder and harder and more frequently. It doesn't stop until complete muscle death, which, by then, you won't need twitches to tell you something is horribly wrong. This is important, because the nerves around it have also begun to lose their connection and are beginning to fasciculate (thus, no new nerve supply can come to the rescue). That means progression of twitching--from a very small localized area with very fine,steady fascics that you cannot even feel or see to a larger group with more intense twitching.
My neuro sees ALS patients come into his office complaining of, say, visible atrophy in their hand. They don't notice the twitching. He then begins to ask them questions about noticeable weakness, and they often say things like "well, now that you mention it, I've been having trouble opening jars." He then puts their hand under a black light (or whatever it was--can't remember) and shows them the fascics.
I think a conclusion can be drawn from what he has told me. ALS twitches are likely incapable of being noticed early on as the muscle is dying, but the resultant weakness and atrophy are not. Sure, when the weakness progresses to affect large areas of surrounding muscle, the twitching becomes intense and noticeable, but by that time, you are having all kinds of physical problems.
If anything, visible twitches are the least likely for concern, because by the time they are visible and thumping, if you have no real weakness, it's benign. But this is also not to say the invisible ones are ALS, either, because I've had very fine twitches in places like my neck and elbow and foot for 2 years now. You don't denerve for two full years and not notice things like not being able to lift your arm or not being able to keep yourself up on both feet. My calves have been visibly ballistic for 2 years straight, and no weakness and no atrophy. In fact, at this point, this intense twitching in my calves actually REASSURES me of a benign condition!
The point I'm trying to make is that whether you can see your twitches or not, you still can't make any conclusions. Everyone twitches. Everyone. Some more than others. What you should watch for are things like falling down constantly or atrophying limbs--and even THEN you are likely not to be diagnosed with it (another story, but I know a girl who has had severe weakness and atrophy in her hand for years and the doctors have definitively ruled out ALS, saying they think it's a viral infection of the brain stem).
Myokymia differs from fascics because there is no nerve (in our case, probably an inflamed nerve) involved in the muscle movement. It is a sort of a wormlike movement of the muscle fiber, and is in no way indicative of anything even remotely serious. Perfectly healthy people have myokymia from time to time. I can describe it best as a rumbling feeling (usually in my quad or hamstring) that rumbles for maybe a few seconds and then goes away.
Now, onto something else. I spoke to a family member this weekend who has long been diagnosed with osteoarthritis and FIBROMYALGIA, and she said her symptoms are twitching, being easily fatigued, muscle soreness, and muscle stiffness (especially in the morning). Sounds a lot like what I have and I suspect a lot like what others here have. It's an inflammation of the nerves in her body, and maybe that is why some here have noticed decreased twitching when taking things like anti-inflammatories.
I'm sure someone will read this and freak out. Just try and remember that if you are already twitching, without serious (the kind of weakness that TELLS you you are weak, not the kind that makes you wonder if you are) weakness and muscle wasting, each day is a day on your side and a confirmation of the benign condition we've been diagnosed with. I asked my neuro in a 12 month follow-up if my twitches from the year prior were ALS-related, would I definitely be having serious muscle weakness, etc., by then and he gave me a very resounding "definitely." It's just a waiting game, really.