SHM Converge Scientific Abstract ePoster Gallery-Personality and Memory Loss: A Case of Autoimmune Encephalitis

Pdf Summary

This case report describes an atypical presentation of LGI1 autoimmune encephalitis (AE) in a 38-year-old woman with hypothyroidism. She initially presented with a four-month history of progressive personality and behavior changes, short-term memory loss, odor-triggered confusion, and headaches. Her initial workup, including CT and MRI brain imaging, was unrevealing, and she was discharged while autoimmune CSF studies were pending. One week later, she returned with new-onset tonic-clonic seizures.<br /><br />On admission, her vital signs and neurologic exam were largely normal aside from leukocytosis. Prior extensive testing, including EEG, lumbar puncture, metabolic studies, toxicology, and infectious workup, had been negative. EEG during this admission showed bilateral subclinical focal seizures requiring multiple antiepileptic medications. A later review of her MRI revealed abnormal bifrontal sulcal and juxtacortical FLAIR hyperintensities, which had initially been read as normal. CSF autoimmune testing eventually returned positive for VGKC-LGI1 antibodies, confirming the diagnosis.<br /><br />Her hospital course was complicated by recurrent seizures and later hyponatremia consistent with SIADH. She was treated with IV steroids, antiepileptic medication adjustment, and later rituximab, after which she remained seizure-free as an outpatient.<br /><br />The report emphasizes that LGI1 AE typically affects older men and is classically associated with faciobrachial dystonic seizures, memory decline, hyponatremia, and medial temporal lobe MRI abnormalities. This patient differed from the classic pattern in several ways: she was a middle-aged woman, had no FBDS, developed tonic-clonic seizures, had delayed hyponatremia, and showed atypical bifrontal MRI findings. The case highlights the need for early recognition of autoimmune encephalitis to avoid misdiagnosis and improve outcomes.

Asset Subtitle

Lucas T. Hopkins

Meta Tag

Author List Chitra Kanyadan, Javeria Naz, Lucas T. Hopkins

Category Clinical Vignettes

Concept Autoimmune Encephalitis

Concept LGI1 encephalitis

Concept Amnesia

Concept Altered Mental Status

Concept Seizure

Distinguished Non-Finalist

Presenter Organization Wellstar Health System

Presenting Author Lucas T. Hopkins

Track Adult

Keywords

LGI1 autoimmune encephalitis

VGKC-LGI1 antibodies

tonic-clonic seizures

hyponatremia

SIADH

memory loss

personality changes

bifrontal FLAIR hyperintensities

rituximab

autoimmune encephalitis

Autoimmune Encephalitis

LGI1 encephalitis

Amnesia

Altered Mental Status

Seizure