A woman thought she was in 'The Walking Dead' and acted like she was on PCP, but it was her immune system fighting a benign ovarian tumor

A recent college grad binged "The Walking Dead" until the show begins to creep into her reality, leading to the discovery of a hidden tumor.

• In "A Molecule Away from Madness," author Sara Manning Peskin recounts stories of brain function gone haywire.
• One chapter details the case of a woman who became delusional and aggressive due to an antibody gone rogue.
• Her immune system was trying to fight an ovarian tumor, but her brain cells got caught in the crossfire.

The summer after graduating college, Lauren Kane binged a lot of TV — specifically, she couldn't get enough of "The Walking Dead."

Her mother didn't think much of her daughter's sluggish behavior; after all, she was a recent graduate and deserved the downtime.

But when Lauren seemed feverish and unsteady on her feet one evening, it prompted a visit to the hospital. In the emergency room, Lauren's mental state began to deteriorate. She grew violent towards her doctors, and in the weeks that followed, her sense of reality blurred with the post-apocalyptic world she had been watching on TV.

Lauren's episode is described further in "A Molecule Away from Madness," a book in which Sara Manning Peskin explores cases of brain functioning gone wrong. Other chapters detail genetic mutations and vitamin deficiencies that can have mind-altering effects, but Lauren's symptoms were caused by a uniquely shaped antibody.

In fact, the molecule to blame looked a lot like PCP, a hallucinogenic drug known for its dissociative effects. Lauren's delusions of fighting zombies, punctuated by episodes of unprovoked aggression, resembled a drug-induced episode, her doctors noted.

But her blood tests returned no sign of drugs, and her brain scans looked normal. The underlying problem turned out to be in her ovary, not her brain: a tiny tumor and her immune's system attempt at destroying it had caused her break from reality.

Her delusions were caused by an antibody gone rogue

In the intake room, one guard had asked if Lauren had taken PCP before she came in. The hallucinogen was briefly used as an anesthetic in the 1960s, but it's now illegal and relatively unpopular among recreational drug users due to its unpredictable effects.

Lauren's symptoms matched the fractured sense of reality experienced by PCP users. In the chapter "A Zombie Apocalypse," Peskin wrote of how the drug blocks a receptor in the brain that typically filters fact from fiction.

Although Lauren had not used PCP, her immune system had created a molecule that fit into the same receptor. With her body producing an unlimited supply of PCP-shaped antibodies, it was as if she was hooked up to an IV drip of the drug, Peskin wrote.

However, the antibody was not meant to bind to receptors in Lauren's brain. Her immune system was initially going after a small, non-cancerous tumor in her right ovary, and her brain got caught in the crossfire.

Ovarian tumors have been linked to this syndrome before

Lauren's tumor was made up of a hodgepodge of cells, including some that looked like neurons carrying NMDA receptors. Her immune system registered the tumor as an invader and began churning out custom-made antibodies to fight it.

Unfortunately, those antibodies were also compatible with the NMDA receptors in Lauren's brain. The antibodies attacked those receptors too, destroying her hold on reality along with them.

Cases of anti-NMDA receptor encephalitis are rare, but Lauren fit the picture of the typical patient. The disease is four times as common in women compared to men, with a median age of 21, according to a 2019 case report. 

The majority of affected women share a type of tumor called a teratoma, which can contain odd bits of tissue such as hair and teeth — or vital receptors usually found in the brain.

Doctors were able to remove Lauren's tumor from her ovary after treating her symptoms with immunosuppressant medications. When she eventually returned to reality, she had no memory of the past two months she spent in the hospital.

It took several more months of rehabilitation to improve Lauren's memory to near-normal, and her diagnosis came with a foreboding statistic: one in five people who make anti-NMDA receptor antibodies will experience a relapse with partial symptoms.