Presentation
Seizures, agitation, fever and reduced level of consciousness for 4 days.
Patient Data
Bilateral hypoattenuation of the temporal lobes and insular cortices (right>left). No associated local mass effect, hydrocephalus or downward herniation. No intracranial hemorrhage or leptomeningeal enhancement.
This limited study demonstrates bilateral asymmetric FLAIR and T2W hyperintense signals involving the medial temporal lobes, insular cortices, and inferior frontal lobes. The basal ganglia are spared—no acute hydrocephalus. DWI/ADC, SWI, and post-contrast imaging sequences were not done as the patient was restless.
Case Discussion
The CSF showed pleocytosis and high protein. Herpes simplex virus (HSV) infection was confirmed on PCR. The limbic system's clinical findings and predominant involvement in imaging are highly suggestive of herpes simplex encephalitis. The patient was commenced on anti-virals but subsequently succumbed to the infection.
Differential includes an MCA territory infarct; however, sparing the basal ganglia helps distinguish it from herpes encephalitis. Autoimmune encephalitis is a consideration within the correct clinical scenario of underlying malignancy.