Symbiosis Center for Medical Image Analysis and Symbiosis Institute of Technology, Symbiosis International University, Lavale, Mulshi, Pune, 412115, Maharashtra, India.
Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Hosur Road, Bengaluru, 560029, Karnataka, India.
J Neurol. 2024 May;271(5):2521-2528. doi: 10.1007/s00415-024-12184-9. Epub 2024 Jan 24.
Free water (FW)-corrected diffusion measures are more precise compared to standard diffusion measures. This study comprehensively evaluates FW and corrected diffusion metrics for whole brain white and deep gray matter (WM, GM) structures in patients with Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) and attempts to ascertain the probable patterns of WM abnormalities.
Diffusion MRI was acquired for subjects with PD (n = 133), MSA (n = 25), PSP (n = 30) and matched healthy controls (HC) (n = 99, n = 24, n = 12). Diffusion metrics of FA, MD, AD, RD were generated and FW, corrected FA maps were calculated using a bi-tensor model. TBSS was carried out at 5000 permutations with significance at p < 0.05. For GM, diffusivity maps were extracted from the basal ganglia, and analyzed at an FDR with p < 0.05.
Compared to HC, PD showed focal changes in FW. MSA showed changes in the cerebellum and brainstem, and PSP showed increase in FW involving supratentorial WM and midbrain. All three showed increased substantia nigra FW. MSA, PSP demonstrated increased FW in bilateral putamen. PD showed increased FW in left GP externa, and bilateral thalamus. Compared to HC, MSA had increased FW in bilateral GP interna, and left thalamic. PSP had an additional increase in FW of the right GP externa, right GP interna, and bilateral thalamus.
The present study demonstrated definitive differences in the patterns of FW alterations between PD and atypical parkinsonian disorders suggesting the possibility of whole brain FW maps being used as markers for diagnosis of these disorders.
与标准扩散测量相比，自由水（FW）校正扩散测量更为精确。本研究全面评估了 FW 和校正扩散指标在帕金森病（PD）、进行性核上性麻痹（PSP）和多系统萎缩（MSA）患者的全脑白质和深部灰质（WM、GM）结构中的应用，并试图确定 WM 异常的可能模式。
对 PD（n=133）、MSA（n=25）、PSP（n=30）患者和匹配的健康对照组（HC）（n=99、n=24、n=12）进行弥散 MRI 采集。生成 FA、MD、AD、RD 扩散指标，并使用双张量模型计算 FW 和校正 FA 图。TBSS 在 5000 次置换下进行，显著性阈值为 p<0.05。对于 GM，从基底节提取扩散图，并在 FDR 下进行分析，显著性阈值为 p<0.05。
与 HC 相比，PD 显示 FW 的局灶性改变。MSA 显示小脑和脑干的变化，PSP 显示额顶叶 WM 和中脑的 FW 增加。所有三种疾病均显示黑质 FW 增加。MSA、PSP 双侧壳核显示 FW 增加。PD 显示左侧 GP 外核和双侧丘脑 FW 增加。与 HC 相比，MSA 双侧 GP 内核对侧丘脑 FW 增加。PSP 右侧 GP 外核、右侧 GP 内核对侧丘脑 FW 增加。
本研究表明 PD 和非典型帕金森病之间 FW 改变模式存在明确差异，提示全脑 FW 图谱可能作为这些疾病诊断的标志物。
