Oh, to those with "twitches" it could be symptomatic of a developing neurological disorder (ie MS or ALS or Parkinsons).. though most twitching could be fasiculations, which are benign and the result of perhaps a lack of certain minerals etc, who knows.
But you will want to go to a neurologist if you're sure its not due to a muscle injury of some sort. Also, if you feel muscle loss around the area of the twitching, that is also not a good sign and more reason to see a doctor asap.