Pressed by her family, he reluctantly agreed to refer her to the epilepsy ward at NYU hospital. It was only because her family didn't believe it that she ended up seeing a second neurologist – 'one of the best in the city' – who told her she just needed to 'lay off the partying'.

She was diagnosed with a mixed episode containing both manic and depressive behaviour and prescribed with an anti-psychotic. What the psychiatrist saw was a psychiatric disorder. He sent her to see a psychiatrist instead. Finally, a blood-and-foaming-at-the-mouth seizure, on the sofa at her boyfriend's flat, led her to see a neurologist. Fear and anger.' She carried on as normal at first, even when the neon signs of Times Square brought on a blinding migraine and the walls of her office 'were breathing visibly, inhaling and exhaling all around me'. 'What I remember most vividly,' she says, 'is the fear. It is, at times, a terrifying read, not least because for much of the time she was herself terrified. So I have these things that are objective facts, but there are still significant blanks.'

And then I interviewed people about myself. So I got my medical records, and I put together a timeline of events – the day I had my brain tap, the day I had my biopsy, and so on.

'The first thing I did was to get the facts. Because I'd been a reporter, I had these tools, but it was an extremely dissociative process. 'I had to bring the idea of journalistic distance to writing about myself. Researching the book involved forensically investigating herself. 'I didn't even know who 'I' was any more.' That uncertainty about herself, and who, under the effects of her illness, she became, is at the heart of Brain on Fire, her account of her illness, a survivor's memoir with a difference: a narrator so unreliable she can't even remember whole scenes that happened to her.įor a while, she disappeared the Susannah Cahalan who was admitted to NYU hospital's epilepsy ward and who, when she watched TV, believed people were talking about her on the news, was not the Susannah Cahalan she'd always known and who she is now. How was she? people continually asked when she was recovering. She's back in zingy red lipstick, drinking coffee in a hipster cafe, pondering the strokes of luck – the bad luck and the good luck – that have brought her here. You wouldn't know any of this meeting Cahalan today. For a period of time, she was, according to the description of one friend, like something from 'a zombie movie'. And, when, eventually, she was admitted to NYU hospital, nobody there knew either. A second neurologist suggested it was 'alcohol withdrawal syndrome' and prescribed different medication.

A psychiatrist said it was bipolar disorder and prescribed medication. The first neurologist she saw told her there was nothing wrong with her.

Cahalan susannah