Could Balance Disorder Be Due To Tylenol?

My wife awoke Weds morning (4/8/15) unable to walk a straight line without tilting/listing to the LEFT. She underwent a series of tests in the hospital ER. They were a CT scan of the head, a sonogram of the carotid arteries, tri-MRI of the head, neck and brain, and a series of eye/hand/foot coordination, as well as strength tests. All these showed no abnormalities. An ENT doctor was consulted for the inner ear and he did not find any problems as well. This problem occurred within a three hour period as my wife was up at 3:00 AM Weds morning and took a Tylenol PM to try and alleviate achy leg syndrome and awoke at 6:00AM unable to walk without falling over to the left. Any help would be appreciated....... Sincerely.........Jim Worley