This is a page-turner. It is easy to read and also well written. Why the three starts then? Because it's not really a story - at least not in the way I expected. Now some explanation is due. 
 There *is* a story here. A very personal, amazing, gripping story of a person who arrived at the gates of insanity and made it back. However, this is more of a long journalistic article, a collection of facts, than the stuff that makes a good tale. That's not a problem, after all Cahalan is a reporter (and good in what she does, judging from this book), but I feel that "my month of madness" would make more sense as an article, or a series of these, than it does in a book form. (Note: an article, which I didn't read, was indeed published, and I believe it's at the end of the book.) 
 Perhaps though, like the title itself, Cahalan cannot let go of the article part: "My month of madness" is precedes the "Brain on Fire" part as if it needs to hold its hand and explain what is really going on. As a book and as story, it fails after Cahalan is hospitalized and gives way to journalistic reporting. In other words, Cahalan stops telling her story, steps out of her body, and tells it as if it happened to another person. Of course, that's the only way she could have done it, considering the nature of her disease; but then, why even tell it as a personal account at all? Why not just write it from a different point of view all the way through? Why not make it into the tale it almost seems to become? Perhaps because the author doesn't know how not to be a news reporter. She can't let go, as if the facts is all that matters. It doesn't, and that's the problem. 
 At the end, this is a good read with a solid entertainment value - especially if you're interested in some real facts about "going crazy" and the science behind it. It gives a good insight. Do not make the mistake of thinking of this as a story though: it isn't.