During an interview with CNN 's Jason Carroll , Thera 's symptoms were apparent : She was twitching uncontrollably , flailing her left arm and jerking her head to one side . School will review environmental tests in the area . Activist Erin Brockovich is looking into a 1970 train derailment . `` Conversion disorder '' causes twitching , stuttering , verbal outbursts . It can be caused by many things including drugs and alcohol abuse.
School will review environmental tests in the area . Activist Erin Brockovich is looking into a 1970 train derailment . `` Conversion disorder '' causes twitching , stuttering , verbal outbursts . It can be caused by many things including drugs and alcohol abuse.