About 6 mo ago my 15 yr old son suddenly started stuttering and having involuntary twitching, usually in one of his arms. There has been no change in the stuttering but the twitching has gone from 2 or3 episodes per week to about ten per day.he says it isn t painful but that he has no warning and no control over them.the twitching usually only lasts a few seconds and he is otherwise completely normal and healthy. One more strange thing is that he seems to have some short term memory loss. Lately, he has been repeating the same story or asking the same question that some one just answered an hour before