involuntary muscle contractions

[gabriel__0]

  I have been having this problem since I was  17 years old, I am now 24 years old;  it does not interfere with my life but it is something that I deal with this everyday and causes me some degree of stress since I dont understand the reasons why it happens, also it is embarasing if this happens in public. I experience this contractions in my amrs and legs, they are uncotrolable once they begin, it makes my hands and legs (sometimes face) twist or get stiff. first I thought it hapened do to anxiety in certain situations, like getting up from a chair when the bell rang, or starting to run when the baseball couch instructed to do so, but now it happens even when I'm by my self, just sitting down,or laying in bed.  Sometimes i'm able to relax and control it  to a certain degrre.I  would like to know is this is somekind of  chemical imbalance, trigger by anxiety, and maybe you can give me some orientaton on what to do.
  Thank you
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Dear Gabriel:
It is difficult for me to determine what you amy have without the opportunity of examining you. With your history, possibilities I can think of include some rare neurological disorders such as kinesogenic dystonia, hyperexplexia, and the stiff man syndrome. These represent some forms of functional or metabolic (neurotransmitter) disturbance in the basal ganglia or in the spinal cord. The best expert to see for any of these problems is a neurologist who is specialized in movement disorders, preferably from a major academic neurology department near you.
In case you live near Cleveland, I can recommend Dr. R.S. Burns or Dr. Erwin Montgomery at the Cleveland Clinic. They are nationally renowned movement disorder experts