Published first-person account
Susannah Cahalan — the month she lost, and the test that found her
What happened
In 2009, Susannah Cahalan was a 24-year-old New York Post reporter when she slid into paranoia, hallucinations, and seizures. She was on her way to a psychiatric diagnosis for a mind that seemed to be breaking.
What it looked like
Erratic behavior, delusions, and episodes that read as psychosis — until seizures and a worsening physical picture pushed her doctors to look deeper.
What the labs found
A spinal fluid test found antibodies against the NMDA receptor — her immune system was attacking her brain. The diagnosis was anti-NMDA receptor encephalitis, an autoimmune brain inflammation. A drawing test (she was asked to draw a clock, and drew all the numbers crowded on one side) helped point her doctors toward the right side of her brain and the right tests.
What changed
Treated for the autoimmune condition rather than only for psychosis, she recovered and went on to write Brain on Fire, the memoir that introduced millions of readers to this diagnosis.
The test that told the story
CSF (spinal fluid) anti-NMDA receptor antibody testing.
Sources: Cahalan, Brain on Fire (memoir, excerpted widely); Psychiatric Times interview/profile; Yale coverage of autoimmune encephalitis.