# Deciphering Involuntary Movements: A Case of Seronegative Autoimmune Encephalitis With a Kaleidoscopic Presentation

## TL;DR

A 22-year-old man with seizure-like symptoms and involuntary movements was diagnosed with seronegative autoimmune encephalitis after ruling out other causes.

## Contribution

This case highlights the diagnostic challenges and management of SAE with atypical involuntary movements and non-epileptic EEG findings.

## Key findings

- The patient's symptoms improved with immunosuppression after ruling out infectious causes.
- EEG was difficult to interpret due to myogenic artifact, but no epileptic activity was found.
- The case emphasizes the need for careful evaluation to distinguish movement disorders from epilepsy.

## Abstract

Seronegative autoimmune encephalitis (SAE) can have a myriad of presenting symptoms including difficult-to-decipher involuntary movements.

A 22-year-old man without significant medical history presented with seizure-like activity, altered consciousness, and numerous extraneous movements. His electroencephalogram (EEG) was difficult to interpret due to excessive myogenic artifact. The patient was intubated due to retained secretions and inability to protect the airway. He was paralyzed, and EEG showed no epileptic activity. He was treated with immunosuppression for SAE after infectious etiologies were ruled out. He clinically improved and was at his cognitive baseline at the last clinic follow-up.

SAE is a rare entity requiring extensive workup and careful exclusion of other etiologies prior to diagnosis. The prognosis varies but can be improved with prompt immunosuppression and appropriate treatment of seizures if present. Involuntary movements need to be carefully evaluated to differentiate movement disorder from epileptic etiology. When titrating medications, diligence is needed so as not to overmedicate, as signified by this case.