If You think you have strongyloides or trichostrongyles this may make sense. The twitching is from 2possible parasitic responses .1) The worms are dying from meds and the reaction they give off(toxins from the bodies , the worms struggling as they die. 2) the encysted ones will be triggered to come out of hibernation and repopulate the colony. they can be in muscles, joints , or wherever they camped in your body , but most will be in intestinal linings . The encysted ones will be with you for awhile , the longer you had them and the severity of the infection will determine if you have a few hundred or many many more. Most will come out in 4to 6 months but some can last for up to 3years . Elevated body temperature from excercise or being outside on hot summer days will speed up the encysted cycle if you are healthy enough .