What is one of the most common causes of limbic encephalitis?
Cancer or tumors (paraneoplastic syndrome)
Given the diagnosis of antibody-negative limbic encephalitis, what is the most likely reason for the 18F-FDG PET/CT being performed?
Evaluate for malignancy (likely paraneoplastic syndrome)
What is the most common malignancy to cause limbic encephalitis?
Small cell lung cancer (SCLC)
How does autoimmune encephalitis typically appear on 18F-FDG PET/CT?
No one common metabolic pattern is seen in all autoimmune encephalitis cases. Some are hypermetabolic only, some are hypometabolic only, and some are a mixture of hypo- and hypermetabolic.
Right greater than left basal ganglia mild CT hypoattenuation corresponding with significantly reduced FDG uptake in the right greater than left basal ganglia.
Focus of intense uptake in the right posterior long gyrus of insula and adjacent subcortical white matter, without anatomic correlate.