The etiological diagnosis and outcome in patients of acute febrile encephalopathy: A prospective observational study at tertiary care center

Background: Acute febrile encephalopathy (AFE) is a clinical term used to an altered mental state that either accompanies or follows a short febrile illness and is characterized by a diffuse and nonspecific brain insult manifested by a combination of coma, seizures, and decerebration. Objective: To identify the etiological diagnosis and outcome in adult patients with AFE. Settings and Design: A prospective observational study was done in patients aged 14 years or above who were admitted with AFE at a tertiary care center in northwest India. Materials and Methods: The non-infectious causes of unconsciousness were excluded and then only a diagnosis of AFE was considered. Cerebrospinal fluid (CSF) analysis and imaging of brain was done to determine the possible etiology. Outcome was assessed at 1 month of follow-up after discharge by using modified Rankin Scale (mRS). Data were analyzed and presented as mean, median, and percentages. A P value of <0.05 was considered significant. Results: Of the total 120 patients studied, pyogenic meningitis was the most common cause accounting for 36.7%, followed by acute viral encephalitis (AVE) in 28.33% of the patients (Japanese B encephalitis in 12.5%, herpes simplex virus encephalitis in 3.33%, and other undetermined viral etiology in 12.5%). Cerebral malaria, sepsis associated encephalopathy (SAE), and tuberculous meningitis were diagnosed in 21.7%, 9.17%, and 4.2% of cases, respectively. Of the total, 16 patients died, 6 with AVE, 3 with pyogenic meningitis, 3 with cerebral malaria, and 4 with SAE. mRS at discharge was >3 in 14 patients with AVE (P < 0.001), and in the remaining it was <3. After 1 month, mRS was >3 in six patients with AVE and in the rest it was <= 1 (P < 0.001). Conclusions: In this study, pyogenic meningitis was the leading cause of AFE, followed by AVE and cerebral malaria. The outcome in cases with AVE can be fatal or more disabling than other etiologies.