What could be causing the twitching?

[worriedhelpme]

I have had issues with my thumb twitching since Aug07 but this has stopped for the last 6 months and my symptoms have been getting better.

For the last two weeks about 30 minutes after I get to work my thumb starts to twitch.  It twitches all day at work for hours.  About 30 minutes after I leave work my thumb starts to stop twitching, and about an hour later it completely stops until I go to work again the next day. Could this be an environmental factor?  Could it be something I am breathing?  My left thumb twitches and pulsates in the part between my thumb and index finger.  I have had an EMG (over a year ago) which came back that I had an overactive nerve or muscle I can’t remember which it was on my left side. Nerve conduction studies came back normal. EEG came back normal.

I would love to figure out what could be causing it.  I do not believe it is stress related.  When I work in another building at my work for the day the twitching does not start.  What could cause something like this?

Thank you

[Lama Chahine, MD]

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. However I will try to provide you with some useful information.

Since your twitching only occurs at work, a pinched nerve or other peripheral nerve problem is unlikely. I am not sure exactly what your EMG showed, but it would be important to clarify this with the physician who did the EMG if there is concern for some sort of peripheral nerve problem.

One possibility is what is termed focal task-specific tremor or dystonia (dystonia is a specific type of muscle contraction). The task that could trigger the tremor could include writing, holding a phone in a specific way, holding a cup or other object, basically any specific sustained motion with the limb in a specific position. Performing the same task in the same position will repeatedly trigger the tremor/dystonia after a certain amount of time, but performing the same task in a slightly different position would not. It could be that for example, a person holds his/her hand in a certain way to write while at work, because of the way the chair and desk are situated etc, but at home on a desk, the hand is in a slightly different position while writing, so the tremor does not occur.

Some regard these task specific movements tremors or dystonias depending on the exact nature of the movement. The cause of these types of tremors or dystonias is not known, but they are usually isolated and benign, meaning that progression to a more serious neurologic problem is unlikely.

If your symptoms are severe enough to be bothersome or interfere with your occupation, evaluation by a neurologist, and specifically a movement disorders specialist, may benefit you. Sometimes, injection of a small amount of botox into the body part that is involved can stop the symptoms with minimal side effects.

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

[TJM24]

I have twitching pretty much 24/7.  I saw two docs, one a neuro for it.  I was convinced I had ALS or some other motor neuron disease.  Mine was mostly in my left calf but it jumped around all over (eye, nose, index finger on right hand, back, etc).  I got an EMG which was negative.  I'd get such bad cramps in my calves I couldn't run or exercise without feeling like I was going to pull a muscle.  Its all benign fasciculations (twitching) according to my doc.  If you've been having this for some time, and have had a clean emg and haven't had any weakness or atrophy, stop worrying about it.  Its just your thumb and you'll probably never figure out what is causing it.  Stress absolutely can make twitching like this more pronounced.  From what docs have said most have no idea what can cause benign twitching.  The important thing is that its benign.  Lastly, I had a stressful prior job and I developed a solid six month left eye twitch that only went away when I changed jobs.  It was clearly underlying job stress/fatigue/too much computer use.  The nervous system is very sensitive and some people have heightened systems where very subtle/minor things can cause it to be overactive.  If you've been cleared via emg and haven't lost strength, I'd try to forget about it.  I was very worried about my twitching until I found out this week that I have a brain aneurysm.  

[worriedhelpme]

Thanks for your response.  I actually have had muscle weakness in my left arm since this all started and it has not gone away.  I have a hard time holding anything in my left hand and the feeling in my finger tips goes away occasionally. It is hard to do any fine motor skills with my left hand. The twitching was constant for over a year and a half, it never stopped 24/7 and always in the one spot between my thumb and index finer. They suspected a pinched nerve in my neck causing the twitching and the pain. What boggles my mind is things were getting better and now
I find certain things set it off again. Like when I get cold very quickly it twitches.  I had ice cream today and it started to twitch for an hour.  I thought it may also be somehow related to diabetes but they did two random glucose checks and my sugar level was fine. I did not do a fasting glucose check.  Should this have been done?

[TJM24]

I've never read anything linking twitching to glucose/diabetes.  Localized twitching like yours does tend to have a pinched nerve/spine cause to it.  Have the weakness motor problems in the last year and a half gotten worse or remained constant?  You may want to go back to your doc and let him/her know.  But I think you can rest pretty assured that if you had the symptoms and had an emg after the twitching started and it was a clean emg, its not any motor neuron problem. Did they check you for any carpal tunnel problems?  Do you use the left hand on the computer/typing/working etc?

[worriedhelpme]

I have been checked for carpal tunnel and it came back negative.  I am right handed and do not over use my left hand in any way. The weakness is pretty much the same, I just have better days and some days that are not that good. I have always suspected that it may be a pinched nerve but since it has been almost 2 years I would have thought it should have healed itself by now? I still have very little grip strength in my left hand.  Any other sugestions?

[TJM24]

I think it sounds very much like some kind of nerve impingement.  2 yrs its been going on, some good days and some bad.  Its definitely not sounding like some progressive nerve disease or anything like that.  Why not go back to the doc and look into the pinched nerve.  Something in your neck or spine, some mild compression could be causing this and you need not suffer with it.