I wanted to take a stab at this one just for the sake that even if Trey has already moved on (which I certainly hope so), or doesn’t read it, that someone else who is tearing themselves apart with panic might.
II can sympathize with what you are going through. Though I hate to admit it, I am a habitual worrier. I check the doors twice to make sure they are locked at night (then occasionally ask my wife if I checked them to make sure). My wife can get away with calling me paranoid because she ruffles my hair when she does it.
There are several people, much more knowledgeable than me, that can and have told you that in the neurological world muscle twitching as a symptom is akin to fever. There are many causes; most of them benign, and of those that remain the vast majority related to treatable conditions. The fact that you have no clinical weakness or atrophy reinforces this.
Use the fever analogy and apply it to the anxiety you are experiencing over ALS. If you had a fever and swollen lymph nodes would your first assumption be that you had bubonic plague? Sounds a little over the top, but those two symptoms are early signs. According to the CDC, a handful of people in the US contract bubonic plague every year. What about fever with headache and nausea? Probably Hanta virus right? I actually had a college professor I was fond of nearly die from Hanta while working in the rural Southwest, and there were documented cases in communities I lived in. Am I trying to tease you or make light of your situation? No, just trying to put it in context with what everyone has been trying to say on the board.
When I first began feeling fasciculation along with other health concerns, I actually thought it was heart related. The pulling in my left bicep and chest felt like pulse-like. Combined with bicep pain, and what I thought was angina, I was sure they were going to find half a french fry blocking an artery.
You want to know the funny thing? I actually felt less stress and concern when I thought I was having a heart attack then later when I had filled my mind with hours reading about neuromuscular disease. With my weight, diet, and stressful job, I am dozens of times more likely to faceplant it in the Walmart parking lot dead of a massive infarction than to contract a terminal nervous system disorder.
When it was first suggested that I might suffer from anxiety, I was offended and felt patronized. “I have two masters degrees from large state institutions,” I thought. “I have had to meet deadlines on several occasions by literally staying up through the night (as I’m sure you might have as well). I’ve been poor enough with children to not know exactly how I was going to pay the bills.” While living in South America, I was mugged, had a gun shot in my direction, and got into an argument with a man whom I found out later had murdered another person in the neighborhood. I “knew” what stress and anxiety felt like. I “knew” what it was like to be on edge.
Then I had the bubbly PA at my GP’s office confess that she had panic attacks in grad school that convinced her that she had something seriously medically wrong with her. I found out that two of the most intelligent and charismatic engineers (rare among engineer’s, the charisma part, I know) I knew were taking medication for depression and anxiety, and whose symptoms had driven them to the doctor’s office. Bright people, not prone to overreaction, with symptoms they thought indicated a potentially life threatening condition. Had they been through extremely stressful situations before? Yes. What was different this time? Who knows?
As others have explained, stress and worry cause real physiological symptoms, many of which are exactly like the ones you describe. Further, when we do have an illness of any kind, worry can make those symptoms worse. You are already doing almost everyone on this board ultimately recommends, and have had very reassuring news.
The “what if” game is as big as you want to make it, and the rabbit hole is deep indeed. Don’t whittle away time you’ll never get back wrestling with an illness that a neurologist has explained there is essentially no indication you have. If you want reassurance re-read what others have already written (I have to give myself this advice often myself). Probing isn’t going to get you any more information, and besides, you’ve been told the doors are locked 4-5 times now :-D