Value of FDG-PET as a Supporting Biomarker for Dementia with Lewy Bodies at Stages of Early Dopaminergic Loss

Ziel/Aim Metabolic network expression and dopamine availability were found to provide complementary information underlying the disease process in Parkinsonism. Disease-Related Patterns (DRP) in ¹⁸ F-fluorodesoxyglucose positron emission tomography (FDG-PET) were proposed to be used as an additional supporting biomarker in early diagnosis of Parkinson’s disease, multi-system atropy, progressive supranuclear palsy and corticobasal syndrome [1]. Therefore, we aimed to evaluate the diagnostic potential of a corresponding metabolic DRP in Dementia with Lewy bodies (DLB) as supporting biomarker in DLB.

Methodik/Methods We used the hitherto largest DLB cohort from the European consortium (E-DLB) with 84 patients having both dopamine transporter single photon emission computed tomography (DaT-SPECT) and metabolic (FDG-PET) imaging biomarkers available. The DLB related pattern (DLB-RP) was computed by voxel-wise comparison against healthy controls. Regional DLP-RP alterations were compared between DLB subjects with and without significant dopamine deficiency (2SD threshold).

Ergebnisse/Results The DLB-RP in FDG-PET was characterized by a relative hypometabolism in the parietal, occipital and, to a lesser extent, frontal and temporal cortices and a relative hypermetabolism in the basal ganglia, parts of the limbic system, the motor cortices and the cerebellum. Subjects without dopamine deficiency already showed a significant parietal hypometabolism and a significant hypermetabolismus in the motor cortex and cerebellum compared to healthy controls, but occipital hypometabolism and limbic hypermetabolism was only present with concurrent dopamine deficiency.

Schlussfolgerungen/Conclusions Patients with clinical DLB and normal DaT-SPECT already express parts of a metabolic DLB-RP in FDG-PET when compared to healthy controls. Detection of metabolic alterations at early stages of dopaminergic loss could serve as a supporting biomarker for timely diagnosis of DLB.

• Literatur/References

• 1 Ko J.H., Lee C.S., Eidelberg D. , Metabolic network expression in parkinsonism: Clinical and dopaminergic correlations. J Cereb Blood Flow Metab, 2017; . 37 (2): p. 683-693.