F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Muscle Uptake in Antiglutamic Acid Decarboxylase Antibody-positive Stiff-person Syndrome.

Antiglutamic acid decarboxylase-65 (anti-GAD65) autoantibodies have been identified in variety of rare neurologic disorders most frequently in stiff-person syndrome (SPS), condition characterized by muscle rigidity and overlying painful spasms, typically affecting axial and limb musculature. In anti-GAD65-related neurologic disorder, malignancy screening is often performed with 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Here, we present an interesting image of 18FFDG PET/CT whole body showing muscle uptake and FDG brain showing thalamic hypometabolism in SPS.