Fig. 14

Early stage (a–d) versus more advanced (e–h) herpes encephalitis. 44-year-old male patient with fever, headache and acute epileptic seizures. 1.5-T axial T2W (a), FLAIR (b) and diffusion-weighted (c) images with an ADC map (d) show subtle T2-FLAIR hyperintensity in the right amygdala and hippocampus with diffusion restriction. Follow-up MRI performed one week later (e–h) shows more pronounced T2-hyperintense bilateral frontotemporal cortical oedema and diffusion restriction, more pronounced in the right hemisphere. PCR was positive for HSV