Even when we know, it's easy to forget that our mental characteristics - our personalities - are just as vulnerable as our bodies to being mutilated by external forces. That's what's so fascinating and so terrifying about Cahalan's experience. When she became paranoid and unstable, some suspected she was having a stress-induced breakdown. (It seems like a reasonable guess; I can't imagine the sort of work habits she described are conducive to long-term mental or physical wellbeing: "Even when the Post kept me out past 4AM working on Meatpacking District club stories, I always made it to the office right on time a few hours later. I never took sick days.") Or, it was suggested, she might be bipolar. But the real cause was inflammation in her brain. That's all it takes to turn a person into someone else.
It's surprising to me how many fruitless examinations she had to go through before they finally detected the inflammation. And then she needed a brain biopsy... I can only begin to imagine the level of dread I would feel at the prospect of someone physically removing a chunk of my brain.
Her case had a happy ending. There's something really heart-warming about her description of how proud and excited she was the first time she wrote an article again after her illness. "Now I met any article, no matter how insignificant, with full and eager enthusiasm." Publicizing her story helped some other patients with the same problem to get correctly diagnosed and treated.