Excellent Outcome of Acute Necrotizing Encephalopathy in an Adult With Bacterial Infections, Case Report

Abstract

Acute necrotizing encephalopathy (ANE) is a rare para-infectious encephalopathy that classically occurs in children. However, ANE should be considered in the differential diagnosis of adults with symmetric brain lesions after a prodromal illness given recent reports of coronavirus disease of 2019 (COVID-19) to presumably cause ANE in adults. We report a case of a 29-year-old male presenting with fever, malaise, and rapid deterioration into coma. Brain magnetic resonance imaging revealed multifocal symmetric areas of diffusion restriction and surrounding vasogenic edema involving bilateral thalami, pons and cerebellar hemispheres with a core of susceptibility artifact, and minimal thalamic contrast enhancement, most consistent with ANE. Extensive infectious workup revealed isolated Escherichia coli and Neisseria gonorrhoeae in his urine. Despite the severe encephalopathy on initial presentation, the patient improved with intravenous antibiotics and supportive management with minimal residual deficits at 9 months follow-up. We aim to provide an overview of the radiological features, differential diagnosis, treatment and prognosis of ANE. Becoming familiarized with this rare but devastating disease will improve detection, treatment, and ultimately prognosis, especially in the era of a new pandemic.

Keywords: MRI; all immunology; all infections; case report; post infectious.

Figure 1.

MRI of the brain. Apparent diffusion coefficient (A, E, I) shows symmetric restriction in thalami, pons, and cerebellum. Thalami lesions (A) are characterized by concentric layers of hemorrhagic necrosis at the inner core, followed by cytotoxic edema in the middle layer, and vasogenic edema at the outermost layer. FLAIR (B, F, J) hyperintensities in thalami, pons, and cerebellum encompass more territory and have edematous appearance. Echo planar imaging (EPI) shows hemosiderin deposition in bilateral thalami lesions (C, G, K). Faint contrast enhancement only seen on thalami lesions on T1 weighted images with gadolinium contrast (T1 + G) (D, H, L).