Case Study

I have a Case Study for you:

45 y/o female is admitted to a Psychiatry unit with a hx of Bipolar Affective Disorder. She has been treated for this successfully and been in remission for a number of years. Her chief complaint is "my legs and arms don't work right". Family reports loss of sleep and the patient has been falling, and has fallen at least 20 times in the past 2 weeks, prior to admission. There are no abnormal lab values. She has contralateral paralysis and vertical nystagmus. She is also having a slight cough. Social hx is negative for alcohol and positive for tobaccoism, with a 35 pack yr hx of smoking. The team and some of the nurses believe she is feigning her sx. What do you think her diagnosis really is???