Imaging in Encephalitis

Abstract

Despite recent advances in diagnostic and therapeutic modalities for infectious and autoimmune encephalitis, the management of patients with suspected or confirmed encephalitis poses a great challenge to physicians. Neuroimaging, including magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning, can play a crucial role in substantiating the diagnosis of encephalitis and eliminating clinical mimics of encephalitis from consideration. Moreover, characteristic neuroimaging patterns can aid in defining specific infectious and autoimmune etiologies. Volumetric and functional MRI, in particular, are being increasingly used to characterize outcomes following encephalitis and can shed light on brain reorganization and function after the acute phase of disease has resolved. Here, we discuss the uses of structural, functional, and PET neuroimaging in the clinical assessment of the acute and recovery phases of encephalitis.

A systematic review of neurological manifestations of SARS‐CoV‐2 infection: the devil is hidden in the details

“…The distinction of encephalopathy and encephalitis needs to be done according to standard criteria [40]. Brain MRI is critical and contrast-enhanced sequences are mandatory [41].…”

Temporal Lobe Hemorrhage as a Complication of HSV Encephalitis, a Case Report

“…The hypothesis include the rupture of the small vessels due to these above causes (11). Magnetic resonance imaging (MRI ) of the brain is the preferred imaging study; T2 images may be more helpful than T1 images (12). Our patient's presentation was consistent with HSV encephalitis but later he developed brain hematoma.…”

COVID‐19 associated brain/spinal cord lesions and leptomeningeal enhancement: A meta‐analysis of the relationship to CSF SARS‐CoV‐2

“…We also found a significant relationship between the presence of CSF autoimmune antibodies and the absence of CNS hyperintense lesions; of the 41 patients who had CSF autoimmune antibody testing, all three patients who had positive results (autoantibodies against: Purkinje cell nuclei/striatal and hippocampal neurons, contactin‐associated protein 2, and N‐methyl‐D‐aspartic acid [NMDA]) had a normal MRI brain 1,16,22–24,33,34, 38,53,54,57,62,67,72–74,77–79,81,82,87,91,94,95,100,104,107,108,111,115,118,119,121 . Patients with autoimmune encephalitis, in general, have a normal MRI brain in ∼33% of cases, but patients with NMDA encephalitis, in particular, have a normal MRI in 50–89% of cases 138,139 . Among patients with autoimmune encephalitis who have an abnormal MRI brain, CNS hyperintense lesions typically involve the limbic system, but can also be present in the cortex, subcortical/deep white matter, basal ganglia, thalami, cerebellum, brainstem, or spine 139 …”