A multimodal MRI-based study of early-stage Parkinson's disease across age-at-onset groups

This study aimed to investigate distinct iron deposition and neurite microstructural alterations in deep gray matter nuclei between early-onset Parkinson's disease (EOPD) and late-onset Parkinson's disease (LOPD) patients using quantitative susceptibility mapping (QSM) and neurite orientation dispersion and density imaging (NODDI), and to evaluate the ability of these quantitative metrics to distinguish EOPD and LOPD from their corresponding healthy controls.

Fifty-three early-stage PD patients (15 EOPD and 38 LOPD) and 58 healthy controls (17 young healthy controls and 41 older healthy controls) underwent multimodal MRI. QSM-derived magnetic susceptibility and NODDI-derived parameters (NDI, Viso, ODI) were analyzed in the substantia nigra pars compacta (SNc), substantia nigra pars reticulata (SNr), red nucleus (RN), globus pallidus (GP), putamen (PT), and caudate nucleus (CN).

In EOPD, the iron content in deep gray matter nuclei was not significantly different from that in young healthy controls, but ODI was reduced in the left SNc. In LOPD, increased QSM values were observed in bilateral SNc, PT, and left CN, alongside decreased NDI and increased Viso in the left SNc, and reduced ODI in bilateral SNc and PT. Multivariate logistic regression analysis revealed that the combination of the NDI and ODI in the left SNc could effectively differentiate patients with EOPD from young healthy controls, whereas the optimal combination for distinguishing patients with LOPD from older healthy controls consisted of the NDI, ODI, and QSM in the left SNc.

Multimodal MRI revealed distinct spatial involvement patterns in early-stage EOPD and LOPD and showed potential for distinguishing PD patients from their corresponding healthy controls.