Dr. Russo arrives to speak to Mom about what the possible diagnoses are. After she lists a few, Mom pulls her into the hallway and asks her personal opinion. Dr. Russo explains that she and Dr. Najjar have a bet: he thinks it's autoimmune encephalitis; she thinks it's paraneoplastic syndrome, which happens when someone has cancer and the immune system attacks healthy parts of the body along with the tumor. This terrifies Mom.
Mom's terror aside, the bet between Dr. Najjar and Dr. Russo develops the idea that these two doctors are, first and foremost, people with their own individual identities outside of their doctor roles. The fact that Dr. Russo shares this with Mom shows that Dr. Russo is truly becoming part of Susannah's community and is willing to trust Mom.
Meanwhile, samples of Susannah's blood and cerebrospinal fluid are on their way to the lab of Dr. Josep Dalmau. Four years earlier, Dr. Dalmau had begun studying four women who developed psychiatric symptoms and encephalitis. All experienced hallucinations, memory problems, and delusions, and they all had tumors called teratomas in their ovaries. He'd discovered that the women's antibodies had been attacking their brains. He performed tests on rat brains and on kidney cells and discovered that that the antibodies were binding to particular receptors, called NMDA receptors. He called the disease anti-NMDA receptor encephalitis.
Finally, Cahalan is able to situate her experience and her story in a much larger story of this disease, anti-NMDA receptor autoimmune encephalitis. Being able to name and describe the disease offers her a way to truly make sense of what happened to her, as these women exhibited the same symptoms that she did. Again, by situating her story within a much larger one, Cahalan encourages readers to apply the story to themselves and their own situations.
Susannah explains that while it's unclear exactly how NMDA receptors in the brain alter behavior, compromising those receptors can be deadly. In tests with mice, decreasing or eliminating those receptors leads to psychosis, catatonia, or respiratory failure, depending on how many receptors they had. By 2007, Dr. Dalmau had diagnosed a hundred patients, not all women, and had developed two tests to diagnose the disease. Susannah would be the 217th person to be diagnosed since 2007. Susannah wonders how many other patients go without a diagnosis worldwide, since it took so long to reach her own diagnosis.
This new information shows Cahalan developing her sense of responsibility towards these other people, and offers up one of the reasons why she decided to write this book in the first place. Unlike medical literature, an easy-to-read and understandable memoir can spread this information very effectively among the general populace. This also explains why her descriptions of medical technology and terminology are purposefully easy to follow.