California Teen Diagnosed With Autoimmune Encephalitis
A 16-year-old girl received treatment after experiencing hallucinations and catatonia linked to rare inflammation.
Updated on Oct. 14, 2026 in Alzheimer’s
Doctors in California diagnosed a 16-year-old girl with autoimmune encephalitis after she presented with hallucinations and a catatonic state. Her condition required intensive medical intervention including immunotherapy over a nearly two-month hospital stay.
Why it matters
Autoimmune encephalitis is a rare condition occurring when the immune system mistakenly attacks nervous tissue, causing severe inflammation. This case highlights the complexity of diagnosing neurological disorders that can mimic psychiatric conditions.
The patient underwent five sessions of plasmapheresis to separate and replace her plasma after testing positive for neuronal intermediate filament autoantibodies. This rare disorder affects an estimated 5 to 8 out of 100,000 individuals.
The players
The Patient
A 16-year-old girl from California who received treatment for autoimmune encephalitis.
The details
After the patient exhibited psychotic symptoms and hallucinations 48 hours before arriving at the ER, medical teams performed a battery of tests including MRIs, CT scans, and an EEG. She was treated with intravenous steroids, immunoglobulin, rituximab, and specific medications including olanzapine and lorazepam to stabilize her symptoms.
Timeline
Four years before ER admission, the patient began experiencing initial hallucinations.
Three weeks before ER admission, the patient and her family suffered a cough.
48 hours before ER admission, the patient developed acute psychotic symptoms.
On her second day in the hospital, the patient entered a catatonic state.
One year following her discharge, the patient stopped taking psychiatric drugs.
Health Landscape
This case follows the diagnostic protocols for autoimmune encephalitis, which prioritize antibody testing over traditional psychiatric diagnosis. The findings contribute to the ongoing refinement of identifying rare inflammatory conditions that manifest through neurological and behavioral symptoms.
The case underscores the importance of medical investigation when psychiatric symptoms appear suddenly alongside physical changes. Patients or caregivers noticing rapid behavioral shifts should prioritize screenings that can rule out underlying autoimmune or neurological triggers.
The takeaway
Recognizing that sudden behavioral changes can stem from immune-related inflammation is critical for seeking the correct specialist care. Early intervention is essential to prevent long-term neurological damage in cases of autoimmune encephalitis.
Further reading
For more information on neurological conditions, visit the Alzheimer’s section.
Source note: This article includes information reported by Livescience.
