muscle spasm
"I have a rye neck from birth- some call it torticolis.  I have rheumatoid arthritis and fibromyalgia diagnosed in 2005.  I have severe neck and shoulder tightness which causes a headache similar to a migraine.  Nothing short of a chiropractor could ever relieve this pain.  Having rheumatoid arthritis I can no longer go to a chiropractor.  This medication is a life saver for me.  It did make me drowsy and a bit goofy the first few days.  Do not drive until you are used to this medication.  It has been a month now and I take 2 or 3 pills only when the neck gets stiff and sore and it relieves the pain and the headache disappears.  This is the first time in 5 years I have had relief from this pain."