Autoimmune encephalitis related to LGI1 antibodies with negative MRI study: Description of two cases

Med Clin (Barc). 2024 Jan 12;162(1):35-38. doi: 10.1016/j.medcli.2023.06.024. Epub 2023 Jul 28.
[Article in English, Spanish]

Abstract

Background: Leucine-rich glioma inactivated 1 (LGI1) antibody-related autoimmune encephalitis is easily misdiagnosed clinically because of its complex and diverse clinical manifestations. We present two cases of LGI1 antibody-related encephalitis with negative imaging findings and perform a literature review on this disease entity.

Case description: The first case was that of a 60-year-old man who presented with involuntary movement of the paroxysmal right limb. The second case was that of a 66-year-old man who presented with hearing hallucinations, involuntary shaking of the right limb, and progressive cognitive impairment. Both patients in this study showed negative magnetic resonance imaging (MRI) results. Routine cerebrospinal fluid (CSF) and biochemical examinations showed no significant abnormalities, and positive LGI1 antibodies were detected in both the CSF and serum.

Conclusion: Based on our experience and the literature review, we recommend that LGI1 antibody-related encephalitis should be considered when faciobrachial dystonic seizures, acute and subacute-onset seizures, low serum sodium (possibly with low CSF chloride), and cognitive-psychiatric disorders are encountered, even in the absence of specific radiographic and altered CSF findings.

Keywords: Autoimmune encephalitis; Encefalitis autoinmunitaria; Imágenes negativas; LGI1; Negative imaging.

Publication types

  • Review
  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Autoantibodies
  • Autoimmune Diseases of the Nervous System* / complications
  • Autoimmune Diseases of the Nervous System* / diagnostic imaging
  • Encephalitis* / diagnostic imaging
  • Glioma* / complications
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Leucine
  • Limbic Encephalitis* / diagnostic imaging
  • Magnetic Resonance Imaging / adverse effects
  • Male
  • Middle Aged
  • Seizures / etiology

Substances

  • Leucine
  • Intracellular Signaling Peptides and Proteins
  • Autoantibodies
  • LGI1 protein, human

Supplementary concepts

  • Autoimmune limbic encephalitis
  • Hashimoto's encephalitis