Evaluating cognitive outcomes in adult patients with acute encephalitis syndrome: a prospective study from a tertiary care center in Nepal

PURPOSE: Although cognitive impairment is a known complication of acute encephalitis syndrome (AES), few studies have evaluated cognitive outcomes in patients with encephalitis. The primary objective of this study was to assess the cognitive profiles of patients diagnosed with AES, which is pivotal for improving rehabilitation strategies and prognostic measures. METHODS: This study was conducted at the Tribhuvan University Teaching Hospital. Adult patients with AES who met inclusion criteria were enrolled. The Montreal Cognitive Assessment (MoCA) tool was used to assess cognitive function at admission, discharge, and 3-month follow-up. RESULTS: Thirty-six patients were enrolled in our study. The mean age of the participants was 43 ± 18 years. Fourteen patients (38.9%) were female, and 22 (61.1%) were male. Tuberculous (TB) meningoencephalitis was present in 14 cases (38.9%), with herpes simplex virus (HSV) encephalitis in 14 (38.9%), bacterial meningoencephalitis in 4 (11.1%), autoimmune encephalitis in 2 (5.6%), and Japanese encephalitis in 2 (5.6%). Patients with bacterial meningoencephalitis had the highest MoCA scores at admission, whereas those with HSV encephalitis had the highest scores at discharge and follow-up. Compared with the scores at admission, the scores at discharge and follow-up increased significantly in patients with TB meningoencephalitis and HSV encephalitis. The MoCA score at discharge was established as a significant predictor of cognitive function at follow-up. CONCLUSION: We found that active treatment can improve the outcomes of AES patients with cognitive impairment. Although infectious etiologies are most common in low-income countries such as Nepal, autoimmune etiologies should not be overlooked.