When immunity 'takes over' the brain: what is autoimmune encephalitis

The diagnosis is autoimmune encephalitis. This is a condition in which the immune system mistakenly attacks brain cells rather than viruses or bacteria. The disease can begin suddenly in a seemingly completely healthy person, writes Medicalxpress.

What it looks like from the outside

One day, Morrill went cycling with friends along the California coast. A walk, lunch - everything went normally, no one noticed anything strange. At home, his wife asked him how the day had gone and he realised he had no memory of the trip at all.

Then it got worse. Memory lapses, delusions, a feeling that he was "losing his mind". In notes from that time, he describes himself as "loose" and "clinging to any ray of light."

In autoimmune encephalitis, the immune system produces antibodies that attack proteins on the surface of nerve cells. Depending on which structures are damaged, the person experiences:

• confusion, sudden forgetfulness;

• personality and behavioural changes;

• seizures, hallucinations, psychosis.

Neurologist Sam Horng from the Mount Sinai system says: if a person quickly develops strange and increasing mental changes, it is important to think in time about the autoimmune cause - this condition can be treated, and it is very dangerous to miss it.

A disease that is often confused with psychiatry

Encephalitis is an inflammation of the brain, and it comes in many different forms. Most often an infection (viruses, bacteria) is to blame, and then it is it that is treated. But if the infection is ruled out, and the symptoms develop quickly, doctors should also consider the autoimmune variant.

The term "autoimmune encephalitis" combines several diseases that are named after target antibodies - for example, anti-NMDA-receptor encephalitis.

This type particularly affects young women and is often associated with ovarian dermoid cysts. Inside these cysts, there may be brain-like tissue, and the immune system begins to produce antibodies against these proteins. If they get into the brain, they attack NMDA receptors on neurons. The result is dramatic changes in mood and behaviour, possibly hallucinations.

In other patients, antibodies attack areas responsible for memory, movement or perception. As Horng says, the end result is that different "facets of personality" are affected.

Now doctors are being helped by an increasingly detailed list of "guilty" antibodies: they are searched for in the blood and cerebrospinal fluid. New variants are described every year.

Treatment: extinguish the inflammation and remove the antibodies

Nowadays, mainly general anti-inflammatory methods are used:

• plasmapheresis (removing antibodies from the blood),

• administration of donor immunoglobulins,

• high-dose steroids,

• sometimes other drugs that inhibit antibody production.

Large clinics are conducting clinical trials of drugs already used in other autoimmune diseases to specifically reduce the production of pathological antibodies.

If diagnosed early, many patients make a full recovery. But there are also residual disorders, like Morrill's.

"I remember Ulysses, but I don't remember my son's wedding."

Christy Morrill has a rather unusual consequence:

• he remembers facts, dates, literary details perfectly (e.g., that "Ulysses" came out in Paris in 1922 in Sylvia Beach's bookshop)

• but decades of personal memories have been erased - trips, family holidays, a year of study in Scotland, his son's wedding.

Even family photo albums don't bring back the emotions and pictures he's experienced. Neurologist Michael Cohen, who treated Morrill, says such selective loss of "autobiographical" memory is rare and immediately makes one think of unusual diagnoses.

In the end, a cerebrospinal fluid analysis showed encephalitis with antibodies to LGI1, a form that is more common in men over 50. These antibodies disrupt the transmission of signals between neurons, and Morrill's MRI showed lesions in key memory areas.

As the search for a diagnosis and treatment progressed, his condition worsened: he gave up kayaking and reading, and experienced severe delusional episodes. He himself describes it as a "complete breakdown" of his psyche.

To make some sense of what was happening, Morrill began writing haiku - short poems in which he tried to capture a sense of illness and hope that the drugs would still "fuel the fire" in his brain.

"I had never heard of this disease."

Another patient, Chiara Alexander from Charlotte (USA), was also unaware of the existence of autoimmune encephalitis before her diagnosis. At first there were little things: a little forgetfulness, episodes of "hang-ups". That all changed when the first seizure occurred and she was taken to the hospital.

The first seizure was blamed on dehydration. After the second seizure, another doctor suspected something more serious and ordered a lumbar puncture, which revealed the same antibodies - against the background of a dermoid cyst of the ovary.

During the treatment, her symptoms worsened, and she barely remembers part of her time in hospital. She was told that she woke up screaming, and what she remembers herself compares it to "a nightmare in which the devil is trying to catch her".

Alexander says she kept asking about her nine-year-old daughter and when she would be released home - and then forgetting the answers again.

She was lucky: she was diagnosed quickly, the cyst was removed, and after more than a year she was able to return to work fully.

More and more known antibodies - and more and more hope

The patient organisation Autoimmune Encephalitis Alliance already counts about two dozen types of antibodies associated with this group of diseases, and the list is growing.

As doctors and patients share their experiences, diagnoses are being made more quickly, which means the chances of recovery are increasing. Alexander says one of the hardest parts of the disease is feeling completely alone and misunderstood by others, so she consciously seeks out and supports other patients.

Morrill, five years after the onset of the disease, is still grieving the loss of his memory, but lives an active life: spending time with his grandchildren, getting out into nature again and leading an AE Alliance support group. There he uses his haiku to describe the journey - from "disintegration" to accepting that the present and future days can still be filled with meaning and joy.

"I'm entering a period of real pleasure and joy again," he says. - I wasn't pursuing happiness. I just wanted to survive. But now I have that, too."