A 24-year old got a mysterious disease where her body attacked her brain — and everyone thought it was in her mind

caroline walsh 2
Caroline, in the middle, with her


There’s a blank year in 25-year-old Caroline Walsh’s
once-spotless memory.

She’s pieced parts together from stories her friends have told
her and a collection of photos on Facebook. But she cannot
remember the day it all began — when her father found her in the
middle of a seizure, her body writhing on the floor. She
also can’t remember waking up with her hands tied to a hospital
bed, begging her sister to help her escape, or the next day when
she proclaimed she was the Zac Brown Band.

Instead, Walsh’s first recollection of that time is of a recovery
room filled with family and flowers. By then, her doctors
had diagnosed her with a mysterious disease called autoimmune
encephalitis, or AE for short. While there’s lot we still don’t
know about the condition, experts believe it’s part of a larger
class of illnesses in which the body turns on itself.

In Walsh’s case, the disease attacked her brain, setting off a
chain reaction of symptoms that mimicked those of other mental
illnesses like depression and schizophrenia. If treated properly
and early enough, people with AE can make a near-complete
recovery. But if they go undiagnosed or land in a psychiatric
ward, they can die.

Something brewing

A stroll down a real street called Memory Lane in London leads
you to the London Institute of Psychiatry, where J.A.N. “Nick”
Corsellis sliced into the brains of three corpses and found the
first evidence of AE.

Deep in the dense part of the brain called the limbic system, the
normally lithe network of rubbery-smooth tissue had become puffy
and inflamed. It was as if something had attacked it from within.

Most of the people these brains once belonged to had been
diagnosed with cancer, then seemed to make a full recovery.
But their personalities
began to change
. A partner or friend was usually the first to
notice an odd shift in their behavior — usually a progressive
increase in forgetfulness, though others experienced a sudden
bout of mania or depression. A 58-year old bus driver found
himself waking up most days not knowing where he was.

Corsellis saw inflammation in parts of the brain linked with
memory and mood, but he couldn’t explain what had caused the
swelling that triggered the symptoms.

“The first question to arise … is whether the assertion of a
connection between carcinoma [cancer] and ‘limbic encephalitis’
is now justified, even if it cannot be explained,” he wrote in a
1968 paper in the journal Brain. It was first time the condition
was mentioned in a scientific journal.

Walsh’s symptoms became noticeable one day at work when she
started repeating herself. She joked with a co-worker that she
was coming down with early-onset Alzheimer’s.

“I was just getting very confused all the time,” Walsh says.

The next week, more mysterious problems cropped up — Walsh had a
knack for remembering names, but one day when she met up with
some new friends, she introduced herself half a dozen times and
struggled to commit anyone’s name to memory.

“They’d say it and then a couple minutes later I’d have no clue
what their name was or what we were even talking about,” she

At the office the next day, things got worse. “My
personality was just off. I thought it was work. I pulled my boss
aside into a conference room and I started to cry, which was just
not me,” she says. When she wasn’t feeling stressed and anxious,
she felt depressed.

“Something was just brewing, I could feel it,” she says.

When the body attacks itself

Our immune system is our body’s defense against the outside

Most of the action is coordinated by white blood cells, which
direct the lines of attack like football coaches, churning out
antibodies that target the opponent for destruction.

white blood cell
A white blood


But sometimes the process can go awry. In generating an immune
response against a virus or other disease, the body can wind
up up attacking itself — a larger class of illnesses
known as autoimmune diseases.

It’s as if “some wires get crossed,” says Brenden
, a neuroradiologist at Henry Ford hospital in Detroit
who’s part of the small community researching autoimmune

Sometimes, this abnormal response can be caused by a virus
like the flu or a bacterial infection. Other times, certain types
of cancer appear to be the source.

“In picking targets that match the cancer, the body may also pick
targets that match places in your body that don’t have cancer,”
says Kelley.

Knee deep in the water

Three months later, Walsh relocated to her childhood home outside
of Boston, and saw two doctors who both incorrectly diagnosed her
with the flu.

Then one morning around 4 a.m., as her dad, a Boston police
officer, got ready for work, he heard a loud crash. He found his
daughter on the ground, her limbs thrashing. He screamed her
name, but she didn’t respond.

The most common cause of the type of seizure that Walsh had that
day — known as a grand mal seizure (literally “great sickness” in
French) — is epilepsy. Other causes can include extremely low
blood sugar, high fever, and stroke.

At the hospital, Walsh’s doctors tested her extensively, doing
multiple lumbar punctures or “spinal taps,” a painful, dangerous
procedure that involves collecting and analyzing the protective
fluid surrounding her brain and spinal cord. In most cases, this
is where doctors will first spot autoimmune encephalitis, Kelley

But sometimes, as in Walsh’s case, the characteristic markers of
inflammation are too subtle to draw a definite conclusion.

caroline walsh 1
Caroline at the hospital.
Caroline Walsh

When Caroline’s sister Alana arrived at the hospital, Caroline
was lying motionless on her hospital bed under the harsh
lighting. Her hands had been encased in heavily padded mitts that
looked like boxing gloves, and were fastened to the railings on
her bed to keep her from pulling out the IV tubes keeping her
hydrated. She asked Alana to come closer so she could whisper
something into her ear.

“You have to fight ’em, you have to get me out of here,” said
Caroline, motioning her head towards the nurses as she eyed them

When Alana asked her sister what she was talking about, Caroline
explained that she’d been abducted while she was asleep and was
now being held hostage at the hospital.

A few hours later, after drifting into the sleepy, dazed state
she was in for much of her hospital stay, she woke with a jolt
and proclaimed she was the country singer the Zac Brown Band. She
started belting out her favorite song of his, a catchy tune about
taking a break from reality called “Knee Deep.”

“Gonna put the world away for a minute,” she sang,
getting louder with every verse. “Pretend I don’t live
in it.”

When her family couldn’t stop Caroline’s crooning, Alana got up
and closed the doors to her room in an attempt to keep her from
waking up everyone on the ward. Caroline continued.

“Mind on a permanent vacation, t
he ocean is my
only medication, w

ishin’ my condition ain’t ever gonna
go away.”

Over the next week, Walsh proceeded to seize more than a hundred
times. Alana recalls that nearly every time she sat down to talk
with her, Caroline would seize half a dozen times. They weren’t
massive seizures like the one that had landed her in the
hospital, but small, barely perceptible ones.

“You’d know because her eyes would drift away and she’d stare in
one spot, she was having little ones almost every minute,” says
Alana. “She was very shaky and confused; her heart rate was
extremely high, and the doctors just seemed so confused by
everything every time we talked to them, they were like she can’t
be going into these seizures all the time, it’s just too much.”

Eventually, the doctors decided to put her in a medically-induced

Smoke from the fire

In children, infections like strep throat appear to be a trigger
of AE. Susan
, a pediatrician in New York, says she’s seen
hundreds of cases of a related condition, called PANS (pediatric
acute-onset neuropsychiatric syndrome), in her patients. Her
first case, in 1998, was a five-year old girl from Brooklyn who
flew into a panic about keeping the clothes she wore on the
Jewish holiday of Shabbat separate from her regular clothes.

“She was driving her mother crazy,” Schulman says. At first, she
believed the girl had childhood
obsessive-compulsive disorder
, but medication made the
child’s symptoms worse, and she returned to Schulman’s office
with more intense OCD symptoms and a nasty case of strep throat.
Strangely, after Schulman treated the strep with antibiotics, the
OCD symptoms vanished.

“I said you know what, that’s odd,” Schulman says.

caroline walsh 3Caroline

Around the same time, an NIH pediatrician named Susan Swedo
published an article
in the American Journal of Psychiatry
describing 50 cases of
a phenomenon she called “pediatric autoimmune neuropsychiatric
disorders associated with streptococcal infections.” Schulman
realized that the sudden psychiatric symptoms she had observed in
her young patients — which ranged from OCD to rage and paranoia —
were likely connected to their infections.

“I see infection as the match that lights the autoimmune
reaction. The inflammation is the fire; the symptoms you see is
the smoke coming out of the fire,” Schulman says.

Autoimmune conditions that affect the brain only represent a
fraction of all autoimmune diseases. Scientists have identified
as many as 80
, which range from type 1 diabetes, which develops when
the body attacks its insulin-producing cells, to multiple
sclerosis, psoriasis, and rheumatoid arthritis. More are being
recognized each year.

Kelley and others at Henry Ford are currently researching
autoimmune diseases that affect the brain. By working with
scientists who specialize in the brain and the immune system,
Kelley hopes to find out what these conditions have in common so
the team can eventually figure out what causes them.

“A lot of these conditions are variants on the same theme,” he

In Walsh’s case, “these are people who tend to not have a lot of
other medical problems and then all of a sudden they feel like
they’re going crazy, they’re losing themselves,” Kelley says. “It
tends to be very clear that something’s not right, but precisely
what’s going on can be difficult to piece together.”

Putting the pieces together

When Walsh woke up in her hospital room, she wasn’t sure why she
was there.

“I was like why are all these people in my room? Why is it
decorated with all of these flowers?,” she recalls.

A day or so before, a specialist had diagnosed Walsh with
autoimmune encephalitis and started her on a regimen of powerful
steroids, now considered one of the best treatments for the
disease. The drugs began to reduce the inflammation in her brain.
In Walsh’s case, the affected area was her hippocampus, the
region responsible for making and storing memories.

“I just remember I kept asking, ‘What?’ you know, ‘Wait, why am I
here?’ and they would tell me, but I kept forgetting,” she says.

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Caroline at Spaulding Rehabilitation


In patients whose autoimmune encephalitis seems to be triggered
by cancer (as opposed to Walsh’s, which may have been set off by
the flu), the treatment focuses on treating or removing the
cancer first. “When you remove the cancer, you remove the
stimulus,” Kelley says.

The treatment for autoimmune encephalitis can vary based on
the trigger, but timing is always key. If doctors treat whatever
is triggering the condition, many people with the disease can go
on to lead fairly normal, full lives.

“It’s a race against time in a way,” Kelley says.

As Walsh began to regain her ability to remember, she realized
she’d have to re-learn a lot of basic things.

“I remember going to get up to use the bathroom, and one of the
nurses went to bring me a wheelchair and I was like, ‘Oh no I
don’t need that,'” says Walsh. “So then I just thought about
standing and suddenly I just had no idea, I couldn’t function to

She regained those skills over the next 10 days at Spaulding
Rehabilitation Center, the same place the survivors of the Boston
Marathon bombing were brought after the attack. There, Walsh
re-learned how to put one foot in front of the other and how to
hold a spoon.

Walsh now works part-time as a nanny and volunteers with
Spaulding and the Boston Boys and Girls Club. Instead of going
back to sales, she plans to work with children in some capacity.
She recently attended a Spaulding fundraising event with her
sister, Alana, where she bumped into the physical therapist who
helped her walk in a straight line for the first time.

“We were in our dresses and we were both dancing together,” Walsh
says, “and Alana was like, ‘You know she taught you to walk