The Clinical Manifestations, Risk Factors, Etiologies, and Outcomes of Adult Patients with Infectious Meningitis and Encephalitis: Single Center Experience.

(1) Background: Central nervous system (CNS) infections, including meningitis and encephalitis, are serious conditions which are associated with high morbidity and mortality. This study aims to identify the clinical manifestations, etiologies, and outcomes of meningitis and encephalitis in adult patients in Saudi Arabia, addressing the current gap in understanding these conditions within this population. (2) Methods: This is a single-center retrospective study which included all adult patients diagnosed with meningitis and encephalitis from March 2016 to May 2022. (3) Results: This study found that most cases of meningitis and encephalitis occurred due to unknown pathogens. Pretreatment with antibiotics prior to lumbar puncture (LP) was found in 71.2% of patients with meningitis. Altered mental status and seizures were common presenting symptoms among patients with encephalitis while altered mental status and fever were common among patients with meningitis. (4) Conclusions: Adherence to guidelines in treating meningitis and encephalitis and performing LPs in a timely manner are important. Establishing national biobanks with biological samples from patients suspected of having meningitis or encephalitis will significantly enhance our understanding of these conditions in Saudi Arabia.