What Causes Progressive Leg Weakness?

Posted on Thu, 2 Feb 2017

Question: Hello, I am a 28 year old male. About 3 weeks ago I was walking and my right leg felt weak like I lost power in that leg. I was still able to walk but it felt funny. I started to worry about ALS. Then later that night that feeling went away. The next day I felt like my left arm was weak, although I was still able to do everyday tasks with it like button a shirt or enter a key in the door. Then that feeling went away but then I started to get muscle twitching on my arms and legs. I do not notice any muscle wasting or atrophy and I am still able to walk fine and do a squat. Sometimes I do have XXXXXXX horses/pain in my leg. The twitching seems to happen more often rightnow and is worrying me. Sometimes I do feel weakness in my leg and arms when I think about it. I did go to the doctor and he doubts this is ALS. He just said to monitor these symptoms, but says it looks like I have good muscle tone. Do these symptoms sound like ALS to you? Thanks.

Answered by Dr. Olsi Taka (1 hour later)

Brief Answer:
Read below

Detailed Answer:
I read your question carefully and I understand your concern.

I do not think that ALS is likely. That is not because of the symptoms in isolation but because of their distribution in time. ALS is an insidiously advancing disease. It may start with weakness in the leg spreading later in the hand but that happens very gradually, over the course of months.
Also weakness is persistent doesn't come and go like in your case. So while you can always consult a neurologist and have an EMG to confirm it, I do not think you should worry much about ALS, anxiety may well be exacerbating those symptoms.

In addition you have another factor which would make ALS extremely unlikely, which is you age. ALS is usually encountered after the age of 45, it is very uncommon under 40, at your age of 28 it would make it an exceptionally rare case.

I remain at your disposal for other questions.

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

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

Thank you Dr. Taka, I appreciate your reply. How about the twitching all over the body, can that be caused by my anxiety and fear? I also heard that once the twitching starts there would already be clinical weakness and muscle wasting, is that correct? Thanks.

Answered by Dr. Olsi Taka (5 hours later)

Brief Answer:
Read below.

Detailed Answer:
Yes usually twitching is on top of the muscle weakness. The muscles which are left without a supplying nerve start to fire spontaneously resulting in the twitches. The fact that they are all over the body so soon confirms it's not ALS (due to its insidious course I mentioned).

Whether anxiety can be responsible for the twitches, yes it can, its one of the most common contributors, often present in what is called benign fasciculations syndrome (BFS, fasciculation is the term for those twitches). However at times (rarely) may be also to electrolyte or thyroid abnormalities, so some routine blood tests (electrolyte panel, creatine kinase, thyroid function) may be done to exclude those.

Let me know if I can further assist you.

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