Unusual MRI findings in an immunocompetent patient with EBV encephalitis: a case report

Abstract

Background: It is well-known that Epstein-Barr virus (EBV) can affect the central nervous system (CNS).

Case presentation: Herein the authors report unusual timely Magnetic Resonance Imaging (MRI) brain scan findings in an immunocompetent patient with EBV encephalitis. Diffusion weighted MRI sequence performed during the acute phase of the disease was normal, whereas the Fast Relaxation Fast Spin Echo T2 image showed diffuse signal intensity changes in white matter. The enhancement pattern suggested an inflammatory response restricted to the brain microcirculation. Acyclovir and corticosteroid therapy was administered. After three weeks, all signal intensities returned to normal and the patient showed clinical recovery.

Conclusion: This report demonstrates that EBV in an immunocompetent adult can present with diffuse, reversible brain white matter involvement in the acute phase of mononucleosis. Moreover, our case suggests that a negative DWI sequence is associated with a favorable improvement in severe EBV CNS infection. More extensive studies are needed to assess what other instrumental data can help to distinguish viral lesions from other causes in the acute phase of disease.

Figure 1

Initial MR imaging of the patient. Magnetic Resonance Imaging of the brain in the acute phase of neurological involvement. Diffusion Weighted MR Imaging of the brain performed in the acute phase of encephalitis (A). Axial T2 FRFSE image shows hyperintensity of white matter with involvement of internal and external capsule (B). Axial T2 FLAIR image demonstrates hyperintensity of white matter; involvement of the ventricular system with reduction in the size of the fourth ventricle is also shown (C). On the T1W Axial FLAIR there is enhancement of cerebral vessels after contrast agent was administered. Hyperintensity of cerebral vessel (D).

Figure 2

MR imaging of the patient at follow-up 3 weeks later. DWI remains the same, without any signal alteration (A). On the Axial T2 FRFSE image, we can see substantial regression of the previous lesions and no new lesions (B). The Axial T2 FLAIR image shows that the fourth ventricle has returned to its normal size. All signal intensities are normalized (C). On the T1W Axial FLAIR there is no enhancement of cerebral vessels after contrast medium was administered, as described above (D).