Objective: To examine local and long-distance dopaminergic changes in prodromal DLB (pDLB) patients in a comparison with matched controls and overt DLB dementia patients.

Background: Dopaminergic deficits are a core feature of dementia with Lewy bodies (DLB). The involvement and reconfiguration of dopaminergic circuitries during prodromal disease is still a theme of debate.

Method: We included twenty patients with pDLB, twenty-nine patients with overt-DLB, and fifty-two CG. Each subject underwent a standardized neurological examination and ¹²³I-FP-CIT SPECT to measure brain dopamine transporter (DAT) density. Spatially normalized images underwent the occipital-adjusted specific binding to obtain parametric data. The ANCOVA was applied to assess dopamine transporter (DAT) uptake differences between clinical and control groups, considering age, gender, and motor impairment as variables of no interest. Between-nodes correlation analysis measured molecular connectivity within the ventral and dorsal dopaminergic networks.

Results: Prodromal DLB and DLB patients showed comparable DAT deficits in basal ganglia regions compared with CG. Molecular connectivity analyses revealed extensive connectivity losses, more in ventral than in dorsal dopaminergic network in overt DLB. On the contrary, the pDLB group was characterized exclusively by gained connectivity compared to CG, mostly involving putamen-thalamus-cortical and striatal-cortical connectivity.

Conclusion: This study indicates a comparable basal ganglia deficit in the DAT system in prodromal and overt DLB, and, also, supports a different reorganization of extra-striatal dopaminergic connectivity, in the prodromal and overt phase of DLB. The shift from an increased to a decreased bilateral putamen-thalamus-cortex connectivity might be a hallmark of transition from prodromal to overt DLB.

« Back to 2022 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/connectivity-of-dopaminergic-networks-in-the-continuum-of-dementia-with-lewy-bodies/