Autoimmune-mediated encephalitis

Autoimmune-mediated encephalitis may occur as a paraneoplastic or as a non-paraneoplastic condition. The role of neuroimaging in autoimmune-mediated encephalitis has changed in the last decade partly due to improvements in sequence optimisation and higher field strength and partly due to the discovery of an increasing number of antibodies to neuronal cell and cell membrane antigens. Imaging is important since it can support the clinical diagnosis particularly in the absence of antibodies. Structural imaging findings can be subtle and are usually best seen on FLAIR images. A progressive as well as a relapsing–remitting course can be observed. Autoimmune-mediated encephalitis is classically linked to involvement of the hippocampus and amygdala, but extensive changes in the temporal cortex, basal ganglia, hypothalamus, brain stem, frontal and parietal cortex are not unusual. This report is based on a review of the literature (except the literature in Japanese) and own findings in patients with autoimmune-mediated encephalitis.