Objective: To determine whether the pattern of nigrostriatal dopaminergic degeneration in DLB mirrors that of “body-first” PD using DAT-SPECT imaging.
Background: Dementia with Lewy bodies (DLB) and Parkinson’s disease (PD) are α-synucleinopathies that share dopaminergic nigrostriatal degeneration but differ in clinical presentation and progression. The α-Synuclein Origin site and Connectome (SOC) model proposes “brain-first” and “body-first” PD subtypes and suggests that DLB may follow a “body-first” trajectory. Whether the nigrostriatal dopaminergic pattern of DLB truly overlaps with that of body-first PD remains unclear.
Method: We retrospectively analyzed DAT-SPECT scans from patients with probable DLB and de novo PD evaluated within two years from symptom onset. PD patients were stratified into “body-first” and “brain-first” subtypes based on polysomnography-confirmed REM sleep behavior disorder preceding motor symptoms. Semi-quantitative DAT-SPECT metrics – including regional specific binding ratios, asymmetry indices, and putamen-to-caudate ratios – were compared across groups, with additional age-adjusted analyses.
Results: Thirty-six patients with DLB, 33 with “body-first” PD, and 36 with “brain-first” PD were included. Compared with both PD subtypes, DLB patients exhibited significantly more symmetric nigrostriatal dopaminergic loss, lower caudate dopamine transporter binding, and higher putamen-to-caudate ratios. No significant differences in any DAT-SPECT metric were observed between “body-first” and “brain-first” PD, both before and after adjustment for age.
Conclusion: DLB showed a symmetric, caudate-weighted DAT-SPECT profile consistent with a more widespread dopaminergic involvement, yet distinct from both PD subtypes. The absence of similar findings in “body-first” PD suggests that DLB may follow a pathophysiological trajectory that is not fully captured by the “brain-first” versus “body-first” dichotomy proposed by the SOC model.
To cite this abstract in AMA style:
G. Palermo, E. Bergamin, G. Bellini, G. Aghakhanyan, D. Frosini, V. Nicoletti, G. Tognoni, D. Volterrani, R. Ceravolo. Nigrostriatal Dopaminergic Patterns in Dementia with Lewy Bodies and Parkinson’s Disease Subtypes: A DAT-SPECT Study within the SOC Framework [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/nigrostriatal-dopaminergic-patterns-in-dementia-with-lewy-bodies-and-parkinsons-disease-subtypes-a-dat-spect-study-within-the-soc-framework/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/nigrostriatal-dopaminergic-patterns-in-dementia-with-lewy-bodies-and-parkinsons-disease-subtypes-a-dat-spect-study-within-the-soc-framework/