Epstein-Barr Virus Encephalitis: A Review of Case Reports from the Last 25 Years

Abstract

Although uncommon, Epstein-Barr virus-related neurological disorders represent the seventh most frequent cause of infectious encephalitis in adults. The limited number of publications on EBV encephalitis mainly document isolated clinical cases. This study aimed to summarize published data on EBV encephalitis. A systematic literature search identified 97 EBV encephalitis cases. In the selected cases, EBV-related neurological disorders manifested as lymphocytic pleocytosis in the cerebrospinal fluid (CSF) with moderate hyperproteinorachia. The EBV PCR test was positive in 87% of the CSF samples, with wide-ranging viral loads. When encephalitis occurred in the context of past EBV infections, all of the EBV PCR tests on CSF samples were positive. On the contrary, negative EBV PCR tests on CSF samples occurred only in the context of primary infections. EBV PCR was rarely carried out on blood samples, contributing minimally to the diagnosis. For the treatment of EBV encephalitis, Aciclovir was used alone in 29% of cases, and in association with other drugs in 40% of cases. Ganciclovir (30%), corticoids (52%), and immunoglobulins (15%) were mainly used in association with other drugs. Cerebral imaging was abnormal in 69% of cases, mostly in the cerebellum and basal ganglia. This work highlights that the EBV PCR test on CSF samples is currently the main laboratory diagnostic test to diagnose EBV encephalitis. This diagnostic test is useful; however, it is imperfect. New complementary diagnostic tools, approved treatments, and standardized practices could improve patient management.

Keywords: Epstein-Barr virus; biology; encephalitis; imaging; treatment.

Figure 1

Distribution of patients by (A) age group ([0, 5[ = from 0 to 5 years excluded), (B) immunity characteristics (number = number of cases), and (C) depending on the final diagnosis.

Figure 2

Distribution of (A) white blood cells in the cerebrospinal fluid (CSF) (N = 79), (B) protein concentrations in the CSF (N = 63), and (C) viral load in the CSF (N = 27) and blood (N = 9) for the reported cases of EBV encephalitis.Horizontal bars represent medians, boxes represent the first quartile (Q1 = 25%) and the third quartile (Q3 = 75%), while vertical bars represent the upper limit (Q3 + 1.5 × (Q3 − Q1)) and the lower limit (Q1 − 1.5 ∗ (Q3 − Q1)).