Knowledge is contagious! Infectious encephalitis is a difficult diagnosis, but patterns on MRI can suggest an etiology. Most know herpes & the temporal lobe Do YOU know any more? Here’s a figure to help you remember the most “common” encephalitis patterns for different organisms Since CSF PCR studies take time, imaging can provide helpful clues: ▶️ Temporal lobe 🔸Although other infectious agents may involve the temporal lobe, statistically this is overwhelming HSV-1 ▶️ Deep Gray 🔸Think of flaviviruses such as Japanese encephalitis & West Nile encephalitis ▶️ Splenium 🔸Think of common infections, especially infections kids get—rotavirus, influenza, COVID. ▶️ Brainstem 🔸This is most commonly enteroviruses (hand, foot and mouth disease). 🔸Remember, all the motor fibers for the hand, foot, & mouth meet in the brainstem, so this is where the encephalitis from hand, foot & mouth will be! ▶️ Infarcts 🔸Think VZV. Varicella and Vasculitis both start with V! ▶️ White matter 🔸Think of immunocompromised viruses (HIV, PML/JC virus) Hopefully, now you will have an infectious curiosity for the MR findings in encephalitis!😂