California Mom on Autoimmune Disorder That Took Away Her Memory: 'I Didn’t Believe I Had a Child’

On June 29, 2019, Shannon McCook was walking into a San Francisco toy store with her 1-year-old daughter, Adelei, and husband, Ryan Peterson, when her body was suddenly taken over by a grand mal seizure. Convulsing and bleeding from the mouth, she stumbled into a rack of greeting cards before her husband, who was holding their daughter’s hand, ran over to stabilize her.

“It happened so fast,” Peterson, 36, tells PEOPLE in this week’s issue. “She started violently shaking. I started screaming for help – I didn’t know what was going on.”

After she arrived by ambulance to Sutter’s California Pacific Medical Center, McCook, 36, suffered another seizure while undergoing an MRI. Over the next couple of weeks, McCook would endure an onslaught of more than 50 seizures—the beginning of a horrific two-month ordeal that would leave her stripped of her memory, battling wild hallucinations and psychotic episodes, and, at times, unable to walk or talk. Diagnosed with autoimmune encephalitis—a rare condition that causes the body’s immune system to attack healthy cells and tissues in the brain —McCook spent 50 days in the hospital (including three days in a medically induced coma), and another two weeks in rehab before she was finally able to go home this past September.

“It was a very frightening feeling that I wasn’t in control of my body anymore,” McCook tells PEOPLE. “I lost sense of who I was.”

Autoimmune encephalitis can be triggered by a viral infection, but in many cases the cause is unknown. “It was only 20 years ago that we thought the vast majority of encephalitis cases were all [caused by] viruses,” says Dr. Prashanth Ramachandran, Clinical Instructor of Neurology at the University of California at San Francisco and one of McCook’s neurologists. “We’ve now realized that 30-40% of known cases are autoimmune.” While there is no known cure, treatment focuses on suppressing the immune system to help limit inflammation and allow injured parts of the brain to heal.

Looking back now, McCook and Peterson, who met through friends on a ski trip in 2014 and married in 2017, both say there were signs that something wasn’t right. In the months leading up to that first seizure, McCook had been feeling uncharacteristically moody and depressed.

“I had feelings of paranoia—even around my friends, emotional mood swings and I would cry myself to sleep sometimes,” she says.

She chalked it up to the stress of her job and being a new mom, but they were likely early signs of the disease.

“Mental health symptoms are often under recognized,” says Dr. Maulik Shah, one of McCook’s neurologists and an Associate Clinical Professor of Neurology at UCSF. “Having prominent memory difficulties and marked sudden changes in personality are subtle clues that there could be something going on beyond depression.”

During her hospitalization, she was at times overcome by dark hallucinations that would wipe out her memory and leave her physically incapacitated—unable to walk or talk.

“I lost my grip on reality,” she says. “I didn’t know my name or where I was from or that I had a husband. I just felt these horrifying monsters had kidnapped me and were planning on killing me. I physically fought back against them, kicking and screaming and biting. I had bruises months later on my hands and arms from where I had to be restrained.”

When Peterson, who was with his wife daily, would try to jar her memory with photos from their wedding or the birth of their daughter, “I felt that it was all a lie,” says McCook. “I didn’t even believe that I had a child.”

Within two weeks, medication brought the inflammation in her brain under control and, as her memory slowly returned doctors prepared to send her to rehab at Alta Bates Summit Medical Center Regional Inpatient Acute Rehabilitation Center in Oakland, California. But just days before her release, McCook suffered a sudden allergic reaction to one of her anti-seizure medications, that sparked a high fever and a painful rash and swelling in her body that began to affect her internal organs. “It was a really scary touch-and-go week,” says Peterson. “Doctors sat me down and started talking about mortality rates.”

Finally, on Aug. 16, McCook was well enough to be transferred to a rehab facility, where she began the arduous process of relearning her basic skills, like how to walk and to read and write.

“It was really challenging— like dusting off old memories,” says McCook, who kept her spirits up by leaning on friends and family for support. “I just wanted to go home to see my baby,” says McCook. “That’s how I got through.”

While McCook has been home since September, her challenges are far from over. Despite taking up to 30 pills a day, to control the inflammation, she still has memory lapses and experiences seizures—she had one recently during a friend’s birthday party.

“I found a park bench and Ryan found me and helped me through it,” she says. “He still cries every time I have a seizure, he feels so bad.”

McCook, who has been unable to return to her job as a branded content editor, also has out-patient therapy three to four times a week for her memory and cognitive skills, and a friend recently created a GoFundMe to help with the ever-mounting medical expenses—including monthly IV infusions to boost her immune system.

The hardest part has been coming to terms with all the time she missed with her daughter, who turned 2 in December. “Ryan will point out different things that I’ve taught her and I don’t remember teaching her those things. That’s so heartbreaking,” she says. “But each and every day it slowly comes back to me—the memories of the kind of mom I was before I forgot what it was like to be a mom.”

Despite the “rough days,” McCook is looking forward to the future. “I’m just grateful to be alive, home and rediscovering myself,” she says. “You have to stay positive. Despite it all, you have to own whatever it is that you’re going through. You’re still you.”