Four months ago my sister in law had a headache, lost conciseness, her vision became blurry and the toes on her right foot began to curl. We took her to the hospital and they did every test imaginable and did not come up with a diagnoses. The best they could come up with is that she had a fall 2 months prior and had an untreated concussion. She was released had has had mild headaches since. Today she passed out again and is having the same symptoms. She is heading back to the hospital now. What could this be? She had an MRI and saw a neurologist, all her blood work was normal as were her vital signs, even when unconscious. Please help.