Title : A rare co-occurrence of streptococcus pyogenes meningitis and anti-N-methyl-D- aspartate receptor encephalitis: A case report
Abstract:
Streptococcus pyogenes meningitis is a rare entity, accounting for less than 1% of bacterial meningitis cases, with fewer than thirty cases reported in the past 25 years. It typically affects young children and older adults. In contrast, anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is the most common autoimmune encephalitis, with an annual incidence of 1.5 per million, frequently associated with ovarian teratomas in women of reproductive age or occurring as a post-infectious complication, most often following herpes simplex virus infection. We describe the case of a 25-year-old female who presented with confusion and seizures, with rapid neurological decline requiring intubation. Cerebrospinal fluid analysis confirmed Streptococcus pyogenes infection by polymerase chain reaction and was positive for anti-NMDAR IgG antibodies. The patient showed marked improvement after initiation of immunosuppressive therapy. This report highlights the unprecedented coexistence of Streptococcus pyogenes meningitis and anti-NMDAR encephalitis, emphasizing the importance of maintaining a high index of suspicion for overlapping infectious and autoimmune etiologies in atypical neuropsychiatric presentations.
Keywords: Anti-NMDAR encephalitis, case report, Bacterial meningitis, Streptococcus pyogenes meningitis
