What Could Twitching Of Legs Suggest?

hi i had a back operation in july of 2008 which was sending of the scale pain down my right leg. is it still normal to still have some twiching down the leg after all this time? ever since the operation i have felt these twiches but not for a while, until the last few day. is this normal? i was told by my Dr that the twiching could come and go for the rest of my life or may stop all togeather.