Is this really necessary at this point?

[Brad4131]

I have been having muscular twitching/fasiculations for the past 6 months or so.  They are located primarily in my calf muscles, although they have occurred in the arms, shoulders, chest, and back.  They occur only in relaxed muscles and stop upon contraction of the affected muscle.  No weakness or atrophy-in fact I either lift weights or walk every day.  Upon prodding from my wife, I talked to my GP about it.  He ran a couple of simple blood tests (fine) and referred me to a neuro.  

I went through a brief consultation/physical exam by a neurologist about 6 weeks ago.  To my knowledge, there were no issues other than the fact he did see my calf and shoulder muscles twitch while I was there.

At that time, he called for some more blood work and asked that I come back in 6 weeks for an EMG.  One of the blood tests he asked for was the Athena Diagnostics FALS screening.  I thought this was very odd as I have no family history of MND.  He did allude to the fact that he was assisting a colleague in a study of FALS.  He also told me not to worry, but he was putting MND as a potential diagnosis so my insurance company would pay for the test.  

After doing a little research on my own, I decided to forgo that particular test as it seems unnecessary to me at this point.  If I understand things correctly, this test screens for a genetic mutation present in 10-20% of patients with FALS.  FALS only accounts for about 20% of all ALS cases, so it would appear we are screening for a small subset of a small subset of a rare condition.

Since my primary concern is peace of mind that the twitching is benign (and since a clean genetic test would not rule out the more prevalent form of ALS), is there any reason at all for me to even consider the genetic test at this point?  To the doctor's defense, I did lose my mother at an early age; but it had nothing to do with mnd; nor is there any history of mnd in her side of the family.

[Neuro Forum]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.

Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is nor can I recommend for or against any genetic testing. However I will try to provide you with some useful information.

You are correct in stating that only a minority of patients with ALS, even familial ALS, will have a mutation in the commercially available gene test for FALS. Therefore, the genetic test may not necessarily exclude the diagnosis of ALS if the test shows no abnormality. However, if it is does show an abnormality, it would help make a diagnosis of ALS. You should not undergo genetic testing unless you are fully informed of the benefits and implications; if you continue to have questions about whether or not to get this test, discussion with a genetic counselor would be one option.

One of the most common cause of muscle twitching in the absence of any other symptoms (weakness, stiffness, difficulty talking or swallowing, and others) is benign fasciculation syndrome, which I will abbreviate as BFS. This is a condition in which there are involuntary twitches of various muscle groups, most commonly the legs but also the face, arms, eyes, and tongue. If the diagnosis is confirmed and other causes are excluded, it can be safely said that the likelihood of progression or occurrence of a serious neurologic condition is low. In such cases, the twitches may be related to anxiety/stress, caffeine, and often occur after recent strenuous activity or muscle over-use. It is important in such cases to reduce stress/anxiety levels and to reduce caffeine intake.

An EMG is a good idea to help exclude other causes and make the diagnosis of BFS. Other conditions, other variants of motor neuron disease besides ALS (such as a condition called Kennedy's syndrome, some viruses, and other motor neuron diseases) could also be suggested or help be excluded with EMG. Continued follow-up with your neurologist is recommended.

Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.

[TJM24]

First off, you sound like classic BFS (benign fasciculation syndrome).  Did your neuro mention this possibility?  If I were you, I'd say "no thanks" to this type of testing.  Get the EMG.  An EMG after this long of twitching would show anything nasty like MND.  In order for fasciculations to be present with MND there would be some weakness/atrophy and the EMG would pick it up. I'm no expert, but I've been through this and am still twitching (mine started in January), but if you are twitching that long and have an EMG come back clean and have a normal clinical exam, I'd guess your doc will be able to rule out MNDs.  
Check out this site if you want to talk to some people with lots of BFS experience:
http://www.nextination.com/aboutbfs/