Anti-N-methyl-ᴅ-aspartate receptor encephalitis preceding stroke: report of an unusual case with literature review.

Anti-N-methyl-ᴅ-aspartate (anti-NMDA) receptor encephalitis is a well-known autoimmune encephalitis caused by antibodies against the GluN1 subunit of the anti-NMDA receptor (anti-NMDAR). Stroke, characterized by abrupt focal neurological deficits due to ischemic or hemorrhagic vascular insults, is rarely preceded by anti-NMDAR encephalitis. Here, we described a case of a 69-year-old female without any prior comorbidities who presented with acute stroke and left hemiparesis with a history of recent onset of neuropsychiatric symptoms. Her cerebrospinal fluid was positive for anti-NMDAR antibody, and significant improvement was noticed after the initiation of immunotherapy. In this patient, stroke occurred following anti-NMDAR encephalitis; however, the pathophysiological link between the two remains unclear. This case presents an interesting and rare clinical intersection between stroke and anti-NMDAR encephalitis, highlighting the difficulty of neurological diagnosis. Due to the unusual association of such pathological conditions, this case contributes to the broader understanding of potential connections between stroke and autoimmune encephalitis, emphasizing the need for a multidisciplinary approach to diagnosis and management.