Pathway Anchored Multimodal Clustering Reveals Circuit Level Signatures in Parkinson's Disease

Vinod, A., Eliendula, A.S., Bhardwaj, S., Dev, A., Dominic, A., Bajaj, C.

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Pathway-Anchored Multimodal Signatures in Parkinson's Disease showing six neuroanatomical circuits

Multimodal biomarker patterns map onto six clinically relevant brain pathways, highlighting disease heterogeneity across motor, cognitive, limbic, and vascular domains.

Key findings

  • A pathway-anchored co-clustering framework (SRVCC) integrates structural MRI, DTI, and DaT-SPECT within six predefined neuroanatomical circuits.
  • Multimodal Pathway Integrity Scores (MPIS) reveal circuit-level imaging heterogeneity linked to motor severity and cognitive function.
  • Five imaging-driven patient clusters emerge with distinct nigrostriatal, frontostriatal, and sensory-visuospatial profiles.
  • Lower nigrostriatal and frontostriatal pathway integrity is associated with higher motor burden; sensory-visuospatial pathway shows the strongest association with cognitive function.
Parkinson's Subgroup Landscape showing nearest-neighbor patient placement

Incoming patients are placed within a population-derived subgroup landscape. The nearest cohort and key clinical features are surfaced to the treating neurologist.

Six neuroanatomical pathways and their clinical associations

Six neuroanatomical pathways — nigrostriatal, frontostriatal, sensory-visuospatial, limbic, microvascular, and balance/cerebellar — mapped to their clinical burden domains.

Cohort and methods

The study draws from the PPMI cohort: 185 Parkinson's disease patients, 72 healthy controls, and 37 SWEDD participants, all with baseline T1 MRI, DTI, and DaT-SPECT imaging.

The SRVCC (Scalable Robust Variational Compositional Co-clustering) framework learns joint patient and feature clusters. Multimodal Pathway Integrity Scores aggregate circuit-specific imaging features (fractional anisotropy, mean diffusivity, regional volume, and specific binding ratios) with equal modality weighting across six predefined PD-relevant circuits.