Tests are only warranted when there is an ongoing condition that suddenly has new symptoms or when symptoms get worse or if they seem to fall into an area where a differential diagnosis is necessary. If you have symptoms of MS which by the way twitching is NOT one of them...I have quite a few MS patients and not a one has ever described twtiching...it is usually if you must know...lightning like shock sensations when they bend their heads forward (not a pulling sensation), the loss of sensation (not pins and needles and feeling like a limb is asleep) where they can not tell if you are touching then with a pin or a piece of cotton, brain fog (they suddenly can not remember things), terrible vertigo (think you are sitting in a chair just fine and then you are on the floor) and bladder issues but usually they present with serious visual issues, then an MRI of the brain is warranted. If there is a change in the reflexes on clinical exam WITH a history of decreased range of motion, muscle pain and/or spasm and/or a history of trauma to the area or familial history of degenerative chages - then a MRI is warranted to look at the spine and the associated neuro tissues to see if there is compression due to arthritis, discs or lesions. Sometimes that can cause much of the symptoms we have BUT understand that it is based on other information found in the history and on examination. That is why some of us have had MRIs.Kit