LGI1 Antibody-Associated Encephalitis Complicated with Sjögren's Syndrome and Acute Cerebral Infarction: A Case Report and Literature Review

Abstract

Background: Anti-LGI1 antibody-associated encephalitis is a rare autoimmune neurological disorder, and primary Sjögren's syndrome is a systemic autoimmune disease with multisystem involvement. The coexistence of these conditions with acute cerebral infarction is extremely rare and highlights complex interactions between autoimmune and vascular mechanisms.

Case presentation: This case report describes a middle-aged female patient diagnosed with LGI1 antibody-associated encephalitis, complicated by Sjögren's syndrome and acute cerebral infarction. The patient presented with an acute onset of symptoms, including delayed response, cognitive impairment, and right-sided weakness. Brain MRI revealed a fresh infarction in the left basal ganglia region. Blood and cerebrospinal fluid tests confirmed the presence of LGI1 antibodies, with blood anti-SS-A antibody levels at +++ and anti-SS-B antibody levels at +, as well as anti- Ro-52 antibody levels at +++.

Conclusions: This report emphasizes the importance of recognizing the overlap between these conditions, as timely diagnosis and intervention can lead to better outcomes in similar cases. By examining the relationship between anti-LGI1 antibody-associated encephalitis, primary Sjögren's syndrome, and acute cerebral infarction, this paper aims to expand the understanding of the complex interactions between autoimmune encephalitis and systemic disorders.