What Causes Involuntary Tremors In Arms?

Posted on Sat, 26 Sep 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sat, 26 Sep 2015 Answered on

Mon, 19 Oct 2015 Last reviewed on

Question : is it common for your arms to shake after about 10 seconds when you are sitting with your arms outstretched behind you to support your back or could this be a sign of als or ms.

Thanks, XXXXXXX

Answered by Dr. Olsi Taka (40 minutes later)

Brief Answer:
No indication of those conditions

Detailed Answer:
I read your question carefully and I am sorry that you have been worrying about such serious neurological diseases.

I can safely say though that you shouldn't worry about either ms or als, not because of that episode at least. ALS doesn't cause limb shaking at all, when there are fasciculation, twitches, they involve isolated muscle fibers groups, not move the limb. Also are not symmetrical or related to assuming certain postures.
It's not typical of MS either, MS can have many presentations but limb shaking is not one of them, only when there is advanced involvement of a limb with paralysis and spasticity can a form of shaking called clonus appear, but obviously your limbs are not paralyzed or spastic. Also at the age of 58 developing ms is very very very unlikely.
As for the cause, what you describe is not a common posture, so it is of no XXXXXXX that your muscles got tired not being able to keep that posture for long and starting shaking.

I remain at your disposal for further questions.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Olsi Taka (1 hour later)

sometimes when I am lying down I have muscles in my upper and lower leg plus muscles in my biceps that twitch periodically and sometime feels like a motor running inside my body. I do not have any problems with speech or swallowing at this point or going up and down stairs sometimes I feel like my balance is off but maybe it could be the medication he prescribed ( 30mg of Mirtazapine), just wanted to see what you make of these problems can stress have a lot to do with this symptoms.
I had a MRI done about 3 weeks ago and my doctor gave me the results and they came back inconclusive is that anything to worry about also I had a few concussions 10 plus years back playing hockey.

Thanks for you time ago XXXXXXX

Answered by Dr. Olsi Taka (3 hours later)

Brief Answer:
Read below

Detailed Answer:
Hello again. If you are worried those twitches are due to ALS I still think that in the absence of weakness and muscle atrophy they do not indicate ALS. Whether stress and anxiety can cause them, yes it can, anxiety can lead to all sorts of manifestations and muscle twitches are the most common one. That motor running inside your body feeling is in no way indicative of ALS either.

As for the MRI, I don't know why it was done. If it was done for ALS, you should know that there are no MRI changes in als, it is done to exclude other causes, so als is not the worry. As for what your doctor has said, I think your doctor should be a little more clear on that. I understand MRI doesn't always make the diagnosis, but still he should tell you whether there are abnormalities and some of the possibilities they indicate, saying it's inconclusive is not enough, can mean anything in the world, doesn't even clarify whether the uncertain findings involve the brain or other structures (ears, sinuses, eye etc). So you should ask your doctor to provide some more detail on that. I am unable to make any comments till then on the MRI, other then considering you have a history of brain trauma some remains of the old injury may be left, sort of like an old scar in the brain, nothing surprising about that.

I hope to have been of help.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar