■先前的影像学研究表明,糖尿病性视网膜病变(DR)与大脑的结构和功能异常有关。然而,DR患者表现出异常神经血管偶联的程度仍在很大程度上未知.
■31名DR患者和31名性别和年龄匹配的健康对照者接受了静息状态功能磁共振成像(rs-fMRI)以计算功能连接强度(FCS)和动脉自旋标记成像(ASL)以计算脑血流量(CBF)。该研究比较了两组之间整个灰质的CBF-FCS耦合和每个体素的CBF/FCS比率(代表每单位连接强度的血液供应)。此外,采用支持向量机(SVM)方法区分糖尿病视网膜病变(DR)患者和健康对照(HC).
■与健康对照组相比,整个灰质的CBF-FCS耦合减少。具体来说,DR患者表现出主要在初级视觉皮层的CBF/FCS比值升高,包括右钙裂隙和周围皮质。另一方面,降低的CBF/FCS比率主要在电机前和辅助电机区域观察到,包括左额中回.
■CBF/FCS比值升高表明DR患者的脑灰质体积可能减少。其比率的降低表明DR患者的区域CBF降低。这些发现表明,视觉皮层中的神经血管去耦,以及辅助运动和额回,可能代表糖尿病视网膜病变的神经病理学机制。
UNASSIGNED: Previous imaging studies have demonstrated that diabetic retinopathy (DR) is linked to structural and functional abnormalities in the brain. However, the extent to which DR patients exhibit abnormal neurovascular coupling remains largely unknown.
UNASSIGNED: Thirty-one patients with DR and 31 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI) to calculate functional connectivity strength (FCS) and arterial spin-labeling imaging (ASL) to calculate cerebral blood flow (CBF). The study compared CBF-FCS coupling across the entire grey matter and CBF/FCS ratios (representing blood supply per unit of connectivity strength) per voxel between the two groups. Additionally, a support vector machine (
SVM) method was employed to differentiate between diabetic retinopathy (DR) patients and healthy controls (HC).
UNASSIGNED: In DRpatients compared to healthy controls, there was a reduction in CBF-FCS coupling across the entire grey matter. Specifically, DR patients exhibited elevated CBF/FCS ratios primarily in the primary visual cortex, including the right calcarine fissure and surrounding cortex. On the other hand, reduced CBF/FCS ratios were mainly observed in premotor and supplementary motor areas, including the left middle frontal gyrus.
UNASSIGNED: An elevated CBF/FCS ratio suggests that patients with DR may have a reduced volume of gray matter in the brain. A decrease in its ratio indicates a decrease in regional CBF in patients with DR. These findings suggest that neurovascular decoupling in the visual cortex, as well as in the supplementary motor and frontal gyrus, may represent a neuropathological mechanism in diabetic retinopathy.