Rare Autoimmune Encephalitis Causes Severe Hallucinations in California Teenager
Clinical case highlights diagnostic challenges when autoimmune disorders mimic acute psychiatric emergencies.
1Acute Presentation and Symptoms
A 16-year-old in California entered an emergency department experiencing severe visual and auditory hallucinations alongside paranoia. Clinical staff observed elevated pulse, rapid breathing, and trembling. The patient interacted with non-existent entities directly in the room, while her family reported an acute behavioral onset occurring just 48 hours prior.
2Initial Medical Workup
Emergency physicians suspected an underlying physical trauma due to unstable vital signs. An initial head CT scan showed no hemorrhage or swelling, and an EEG revealed no anomalies. Initial attempts to collect cerebrospinal fluid failed, prompting pediatric admission rather than an immediate psychiatric transfer due to medical instability.
3Onset of Catatonia
On her second inpatient day, the teenager developed complete catatonia, severely disrupting her responsiveness and motor function. Clinicians administered lorazepam to modulate nervous system signaling, which resolved the catatonic state within days. A subsequent lumbar puncture initially showed normal spinal fluid panels before specialized autoantibody testing occurred.
4Identification of Anti-NIF Antibodies
Follow-up laboratory panels on the patient's cerebrospinal fluid returned positive for autoantibodies targeting neuronal intermediate filament proteins. These structural proteins support nerve cells, and their disruption triggered inflammatory neurological damage. This finding led to a formal diagnosis of autoimmune encephalitis manifesting through primary psychiatric and motor symptoms.
5Ruling Out Underlying Tumors
Because autoimmune encephalitis often arises as a paraneoplastic syndrome triggered by underlying tumors, medical teams performed extensive MRI and PET imaging. These diagnostic scans revealed no malignancies. Consequently, doctors investigated other potential immunological triggers, including a recent systemic respiratory illness the patient contracted during international travel.
6Intensive Immunotherapy Regimen
Treatment commenced with intravenous steroids and donor-derived immunoglobulins to suppress systemic inflammation. Clinicians also administered rituximab to deplete B lymphocytes responsible for generating harmful antibodies. Additionally, the patient underwent five sessions of plasmapheresis across one month to mechanically filter out circulating autoantibodies from her plasma.
7Long-Term Recovery Trajectory
The patient was discharged after nearly two months of hospitalization on a regimen of prednisone, lorazepam, and olanzapine alongside monthly immunoglobulin infusions. Over the following year, her symptoms resolved sufficiently to discontinue antipsychotic medications while maintaining regular immunotherapy protocols to prevent secondary inflammatory relapses.
8Clinical Implications and Rarity
Affecting roughly five to eight per 100,000 individuals, pediatric autoimmune encephalitis typically involves anti-NMDA receptors rather than neuronal intermediate filaments. This case underscores the necessity of comprehensive spinal fluid antibody screening when evaluating sudden, treatment-resistant psychotic symptoms in previously healthy pediatric and adolescent populations.