Dual-tracer [ 18 F]-AV133 and [ 18 F]-FDG PET/MR multiparametric characterization of Parkinson's disease motor subtypes.
Combined PET/MR imaging accurately distinguishes tremor-dominant from postural-instability Parkinson's subtypes.
Dual-tracer [ 18 F]-AV133 and [ 18 F]-FDG PET/MR multiparametric characterization of Parkinson's disease motor subtypes.
Two major motor subtypes are widely recognized in Parkinson's disease (PD): tremor-dominant (tremor-dominant) subtype and the postural instability-gait difficulty (postural instability-gait difficulty) subtype.
This study aimed to investigate the neural correlates of tremor-dominant and postural instability-gait difficulty subtypes using multiparametric analysis with hybrid positron emission tomography/magnetic resonance (PET/MR) and two tracers: [ 18 F]-fluoropropyl-(+)-dihydrotetrabenazine ([ 18 F]-AV133) and [ 18 F]-fluorodeoxyglucose ([ 18 F]-FDG).
A total of 42 patients with PD (22 tremor-dominant, 20 postural instability-gait difficulty) and 27 healthy controls (healthy controls) were enrolled.
PIGD-PD also exhibited reduced [ 18 F]-FDG uptake in the lateral/medial prefrontal cortices (P=0.008 and 0.019), putamen (P<0.001), thalamus (P<0.001), pons (P<0.001), and cerebellum (P<0.001).
For PIGD-PD patients, correlation analyses revealed that bilateral putaminal [ 18 F]-AV133 binding, prefrontal/putaminal [ 18 F]-FDG uptake, and gray matter volume in the orbital superior frontal gyrus, middle temporal gyrus, and cerebellum were significantly negatively correlated with UPDRS-III scores (r ranging from -0.833 to 0.607, all P<0.05).
TD-PD and PIGD-PD exhibit distinct patterns of presynaptic dopaminergic dysfunction, cerebral hypometabolism, and gray matter atrophy.
These neuroimaging differences may partially account for the divergent clinical manifestations between the two motor subtypes, Multimodal integration achieved excellent discrimination.