Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
Department of Psychiatry, Center for Psychiatric Neuroscience, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Prilly, Switzerland.
Schizophr Bull. 2023 Jan 3;49(1):196-207. doi: 10.1093/schbul/sbac113.
Although the thalamus has a central role in schizophrenia pathophysiology, contributing to sensory, cognitive, and sleep alterations, the nature and dynamics of the alterations occurring within this structure remain largely elusive. Using a multimodal magnetic resonance imaging (MRI) approach, we examined whether anomalies: (1) differ across thalamic subregions/nuclei, (2) are already present in the early phase of psychosis (EP), and (3) worsen in chronic schizophrenia (SCHZ).
T1-weighted and diffusion-weighted images were analyzed to estimate gray matter concentration (GMC) and microstructural parameters obtained from the spherical mean technique (intra-neurite volume fraction [VFINTRA)], intra-neurite diffusivity [DIFFINTRA], extra-neurite mean diffusivity [MDEXTRA], extra-neurite transversal diffusivity [TDEXTRA]) within 7 thalamic subregions.
Compared to age-matched controls, the thalamus of EP patients displays previously unreported widespread microstructural alterations (VFINTRA decrease, TDEXTRA increase) that are associated with similar alterations in the whole brain white matter, suggesting altered integrity of white matter fiber tracts in the thalamus. In both patient groups, we also observed more localized and heterogenous changes (either GMC decrease, MDEXTRA increase, or DIFFINTRA decrease) in mediodorsal, posterior, and ventral anterior parts of the thalamus in both patient groups, suggesting that the nature of the alterations varies across subregions. GMC and DIFFINTRA in the whole thalamus correlate with global functioning, while DIFFINTRA in the subregion encompassing the medial pulvinar is significantly associated with negative symptoms in SCHZ.
Our data reveals both widespread and more localized thalamic anomalies that are already present in the early phase of psychosis.
尽管丘脑在精神分裂症的病理生理学中具有核心作用，导致感觉、认知和睡眠改变，但该结构内发生的改变的性质和动态在很大程度上仍难以捉摸。我们使用多模态磁共振成像（MRI）方法，研究了以下问题：（1）异常是否存在于不同的丘脑亚区/核；（2）是否存在于精神病早期（EP）；（3）在慢性精神分裂症（SCHZ）中是否恶化。
分析 T1 加权和弥散加权图像，以估计灰质浓度（GMC）和从球平均技术获得的微结构参数（神经元内体积分数[VFINTRA]、神经元内弥散率[DIFFINTRA]、神经元外平均弥散率[MDEXTRA]、神经元外横向弥散率[TDEXTRA]），分析了 7 个丘脑亚区。
与年龄匹配的对照组相比，EP 患者的丘脑显示出以前未报道的广泛的微结构改变（VFINTRA 减少，TDEXTRA 增加），这与整个大脑白质的类似改变相关，表明丘脑白质纤维束的完整性改变。在两个患者组中，我们还观察到更局部和异质的变化（GMC 减少、MDEXTRA 增加或 DIFFINTRA 减少），在丘脑的中背侧、后外侧和腹前侧部分，表明改变的性质在亚区之间存在差异。整个丘脑的 GMC 和 DIFFINTRA 与整体功能相关，而包含内侧丘脑枕的亚区的 DIFFINTRA 与 SCHZ 的阴性症状显著相关。
我们的数据揭示了广泛存在和更局部的丘脑异常，这些异常已经存在于精神病的早期阶段。
