Brain CT scan (with/without contrast). Complete prior to lumbar puncture to exclude significantly increased ICP, obstructive hydrocephalus, mass effect Brain MRI—Increased T2 signal intensity in frontotemporal region → viral (HSV) encephalitis
Herpesviral encephalitis
Japanese encephalitis
Viral encephalitis
Herpesviral meningitis
Tick-borne encephalitis
Eastern equine encephalitis
Fungal meningitis
Postvaccinal encephalitis