Montagnese Marcella, Mehta Mitul A, Ffytche Dominic, Firbank Michael, Lawson Rachael A, Taylor John-Paul, Bullmore Edward T, Morgan Sarah E
Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0SZ, UK.
Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 8AF, UK.
Brain Commun. 2025 May 16;7(3):fcaf185. doi: 10.1093/braincomms/fcaf185. eCollection 2025.
Hallucinations negatively impact quality of life in Parkinson's disease, yet their neural mechanisms remain poorly understood, particularly in early disease stages. This study aimed to identify functional connectivity differences associated with visual hallucinations in early Parkinson's disease and to validate these findings across independent datasets. Resting-state functional MRI data from two independent studies were used: the 'Parkinson's Progression Markers Initiative' dataset was used as a discovery cohort ( = 25 hallucinators, = 56 non-hallucinators) and the 'Incidence of Cognitive Impairments in Cohorts with Longitudinal Evaluation' dataset as replication ( = 49 hallucinators, = 55 non-hallucinators overall). Group differences in functional connectivity were assessed within predefined cytoarchitectonic cortical classes and functional networks, followed by whole-brain analysis using Network-Based Statistics. This method identified a subnetwork of reduced functional connectivity in hallucinators, connecting regions involved in the default mode, somatomotor and attentional networks. Associations with clinical measures-including hallucination severity, motor symptoms, cognition and attention-were evaluated. Reduced functional connectivity in hallucinators was significantly associated with baseline and future motor symptoms, cognition and attention in the main cohort and with hallucination severity in the independent cohort. The identified functional subnetwork offers a potential direction for future research on Parkinson's disease psychosis.
幻觉对帕金森病患者的生活质量有负面影响，但其神经机制仍知之甚少，尤其是在疾病早期阶段。本研究旨在确定早期帕金森病中与视幻觉相关的功能连接差异，并在独立数据集中验证这些发现。使用了来自两项独立研究的静息态功能磁共振成像数据：“帕金森病进展标志物计划”数据集用作发现队列（幻觉患者 = 25例，非幻觉患者 = 56例），“纵向评估队列中的认知障碍发生率”数据集用作复制队列（总体幻觉患者 = 49例，非幻觉患者 = 55例）。在预定义的细胞构筑皮层类别和功能网络内评估功能连接的组间差异，随后使用基于网络的统计方法进行全脑分析。该方法在幻觉患者中识别出一个功能连接减少的子网，连接涉及默认模式、躯体运动和注意力网络的区域。评估了与临床指标（包括幻觉严重程度、运动症状、认知和注意力）的关联。幻觉患者中功能连接减少与主要队列中的基线和未来运动症状、认知和注意力以及独立队列中的幻觉严重程度显著相关。所识别的功能子网为未来帕金森病精神病研究提供了一个潜在方向。
