Across hospitals from California to Europe, neurologists are seeing a quiet rise in a rare brain condition that looks, at first glance, like stress, burnout or even a psychotic break. Yet behind the confusion, hallucinations and terrifying memory blackouts lies an immune system that has turned on the brain itself.
When an ordinary day suddenly unravels
One morning, 72‑year‑old Christy Morrill set off for a familiar bike ride along the California coast. The weather was clear, the route routine. When he got home, his wife asked how it went. He couldn’t remember the ride at all.
Over the following weeks, the gaps widened. Whole conversations vanished. Family milestones blurred. Then came the delusions, agitation and growing disconnection from reality. What doctors eventually diagnosed was not early dementia, nor a psychiatric crisis, but autoimmune encephalitis – an inflammatory attack on his brain triggered by his own immune system.
Autoimmune encephalitis is a rare but increasingly recognised disease where antibodies target the brain, causing rapid changes in memory, behaviour and perception.
This illness can arrive without warning in people who have never previously been ill, and at almost any age. For some, the first sign is a small slip: difficulty concentrating, losing track of a sentence, misplacing objects. For others, the onset is dramatic, with seizures, hallucinations or violent agitation that leads straight to emergency admission.
What autoimmune encephalitis actually does to the brain
In autoimmune encephalitis, the body’s defence system misidentifies parts of the brain as a threat. It produces antibodies that latch onto crucial receptors on nerve cells, such as NMDA or AMPA receptors, which are key for memory, mood and thinking.
Once those receptors are blocked or disrupted, communication between neurons falters. The result is a bewildering cocktail of symptoms that can shift day by day.
- Short‑term memory loss and difficulty learning new information
- Confusion and disorientation, even in familiar places
- Changes in personality or behaviour, such as aggression or apathy
- Hallucinations, delusions or strong paranoia
- Seizures or unusual movements
- Problems with attention, planning and decision‑making
Some patients talk fluently yet forget what was just said. Others seem outwardly calm while inside they are lost, unable to follow a conversation or remember simple instructions. An Australian research team has highlighted how even basic tasks like writing an email, cooking a meal or paying a bill can become overwhelming obstacles.
People with autoimmune encephalitis can look “normal” at first glance, while silently battling severe cognitive chaos.
When a brain disease is mistaken for a psychiatric disorder
Because early symptoms often involve behaviour and mood, many patients first land in psychiatric units. That misdirection can last for months, or even years.
One published case described a woman treated for schizophrenia for more than two decades. She received antipsychotic drugs, saw therapists and cycled through hospital stays. Only when a neurologist ordered a spinal fluid test did specialists detect antibodies against NMDA and AMPA receptors. Once she was given targeted immune therapy, her thinking and behaviour improved for the first time in years.
Doctors stress that not everyone with psychosis has autoimmune encephalitis. Yet the overlap is large enough that neurologists now push for more routine antibody testing in patients with abrupt-onset hallucinations, catatonia or severe cognitive decline, especially if seizures or fluctuating confusion are also present.
The hidden toll on work, study and relationships
Even when the diagnosis comes relatively early, the condition can turn everyday life into an exhausting obstacle course. Studies suggest that roughly a third of patients never fully return to previous work or study levels.
Short‑term memory gaps make complex jobs nearly impossible. Processing information slows, so meetings feel like listening through thick glass. Fatigue is crushing. Many patients say that by the afternoon their brain has simply “checked out”.
Relationships also shift. Partners and children may feel as though the person they knew has been replaced by someone more anxious, suspicious or withdrawn. Because the illness often leaves no visible mark – no bandages, no cast – friends may struggle to understand why the person is still “not back to normal” months after leaving hospital.
The most painful part for some survivors is not a missing holiday or forgotten party, but the sense that their own life story has holes they can never patch.
Searching for triggers: from tumours to hidden infections
Doctors divide autoimmune encephalitis into cases with a clear trigger and those without. In some patients, a tumour, especially a small ovarian growth called a teratoma, appears to spark the immune attack.
That was the case for Kiara Alexander, a young mother in North Carolina who suffered a sudden seizure and dramatic behavioural changes. Tests revealed antibodies against NMDA receptors, and scans later uncovered an ovarian cyst. Surgeons removed the growth and she began a long course of immune therapy. It took more than a year before she felt ready to return to work.
In other cases, a recent viral infection, such as herpes simplex or – more recently studied – Covid‑19, may prime the immune system into misfiring. Sometimes no trigger can be found at all.
| Potential trigger | Examples | Clinical approach |
|---|---|---|
| Tumour‑related | Ovarian teratoma, lung or breast cancer | Urgent search and removal of tumour plus immune therapy |
| Post‑infectious | Herpes encephalitis, respiratory viruses | Treat infection, then manage immune reaction |
| Unknown cause | No clear trigger identified | Broad immune suppression and long‑term follow‑up |
Treatments that calm an immune system in revolt
Once suspected, autoimmune encephalitis is often treated as a medical emergency. The goal is to stop the immune attack quickly and prevent permanent damage.
Standard first‑line therapies include:
- High‑dose corticosteroids to reduce inflammation
- Intravenous immunoglobulins (IVIG) to modulate the immune response
- Plasma exchange, a procedure that removes harmful antibodies from the blood
If the response is incomplete, doctors move to second‑line drugs, such as rituximab or cyclophosphamide, which more strongly dampen or reset parts of the immune system. Clinical trials are now assessing newer agents used in other autoimmune diseases, with the hope of achieving more precise and longer‑lasting control with fewer side effects.
Timing makes a major difference: patients treated early tend to regain more of their memory, independence and personality than those whose diagnosis is delayed.
Learning to live with gaps in the story
Even after treatment, many survivors face a long rehabilitation. Some memories never return. In Christy Morrill’s case, he retained an impressive store of facts and general knowledge, yet forgot deeply personal episodes: his son’s wedding, trips with his wife, even a year spent studying in Scotland.
To rebuild a sense of self, he keeps diaries, writes short poems and leads a support group for others with autoimmune brain conditions. These activities help him structure his days and slowly regain confidence in his thinking. He says he can now feel moments of calm happiness “without having dared to hope for it”.
Neuropsychologists often recommend practical strategies such as:
- Using phone reminders and calendars for every task, even small ones
- Breaking complex activities into short, clearly defined steps
- Scheduling demanding mental work for times of peak energy, usually mornings
- Involving family or friends in appointments to help remember instructions
Key terms that patients and families keep hearing
The jargon around autoimmune encephalitis can sound overwhelming. Three expressions come up again and again.
- Antibodies: Proteins made by the immune system to target specific threats. In this disease, they mistakenly attack brain receptors.
- CSF (cerebrospinal fluid): The clear liquid bathing the brain and spinal cord. Doctors analyse it via lumbar puncture to look for antibodies and inflammation.
- Relapse: A new phase of symptoms after a period of improvement, sometimes triggered by infection, stress or changes in medication.
Understanding these terms helps families ask sharper questions and push for appropriate testing when symptoms change. For instance, a sudden return of confusion after months of stability might suggest a relapse that needs prompt immune treatment, not just an adjustment of psychiatric medication.
What families can realistically expect
Prognosis in autoimmune encephalitis varies widely. Some patients, especially those treated within days or weeks, return nearly to baseline, with only subtle memory lapses. Others live with lasting difficulties in complex thinking, fatigue or mood regulation, even years after hospital discharge.
Relatives often ask whether the person they love will “come back”. Neurologists usually avoid firm promises. Instead, they talk about trajectories: the fastest gains often happen in the first six to twelve months, followed by a slower phase of adaptation and compensation. Emotional recovery can lag far behind physical progress, particularly in younger patients who must rethink careers, studies or parenting roles.
Support groups, occupational therapy and realistic workplace adjustments can make a decisive difference. A job that allows flexible hours, written instructions and quieter environments may enable someone with lingering cognitive issues to keep working, whereas a high‑pressure, multitasking role might be impossible.
For now, the rise in recognised cases reflects both better testing and a genuine increase in autoimmune diseases worldwide. As research advances, the challenge is not only to refine treatments, but also to catch the illness earlier – before it steals memories that no drug can ever fully restore.
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