Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China.
Stroke. 2021 Jul;52(7):2319-2327. doi: 10.1161/STROKEAHA.120.032464. Epub 2021 May 11.
Ipsilateral thalamic diaschisis (ITD) initially describes functional depression of the thalamus ipsilateral to a supratentorial lesion, but accumulating evidence has shown morphological changes also occur. Therefore, we aimed to characterize thalamic perfusion and diffusion related to ITD over time and their inter-relationships after middle cerebral artery infarction.
Eighty-five patients with middle cerebral artery infarction who underwent diffusion kurtosis imaging and arterial spin labeling were retrospectively included. ITD was diagnosed as ipsilateral thalamic hypoperfusion present on ≥2 cerebral blood flow maps. The thalamic asymmetrical index was calculated as (ipsilateral value−contralateral value)/contralateral value×100%. Finally, the inter-relationships of thalamic perfusion and diffusion were analyzed.
ITD was present in 56/85 patients (65.9%, ITD+). In ITD+ patients, larger abnormal perfusion volume, higher perfusion-infarct mismatch and lower rates of focal hyperperfusion were observed than ITD− patients. Infarction affecting the corona radiata were more frequent among ITD+ patients. Mean kurtosis were slightly but significantly increased within the ipsilateral thalamus compared with the contralateral one in ITD+ patients of subacute and chronic groups, while fractional anisotropy was significantly increased in subacute group but decreased in chronic group for both ITD+ and ITD− patients. Mean diffusivity was significantly increased in ITD+ patients of chronic group. Furthermore, the AICBF was negatively and significantly correlated with AIMK and AIFA in ITD+ patients in subacute group, and AIMD, even after adjustment for abnormal perfusion volume and days from symptoms onset, in chronic group. ITD+ patients had significantly higher National Institutes of Health Stroke Scale and modified Rankin Scale scores at admission and discharge and also showed a trend to independent association with clinical outcome at discharge.
The combination of arterial spin labeling and diffusion kurtosis imaging can reveal early, time-specific thalamic perfusion and diffusion changes after middle cerebral artery infarction. ITD-related hypoperfusion was significantly correlated with underlying microstructural alterations.
同侧丘脑去抑制（ITD）最初描述的是大脑上病变对侧丘脑的功能抑制，但越来越多的证据表明，其形态也会发生变化。因此，我们旨在描述大脑中动脉梗死后随时间推移 ITD 相关的丘脑灌注和弥散的特征，以及它们之间的相互关系。
回顾性纳入 85 例接受弥散峰度成像和动脉自旋标记的大脑中动脉梗死患者。诊断同侧丘脑低灌注的 ITD 标准为≥2 张脑血流图上存在同侧丘脑低灌注。计算丘脑不对称指数作为（同侧值-对侧值）/对侧值×100%。最后，分析丘脑灌注和弥散的相互关系。
85 例患者中，56 例（65.9%，ITD+）存在 ITD。与 ITD-患者相比，ITD+患者的异常灌注体积较大、灌注-梗死不匹配较高、局灶性高灌注率较低。ITD+患者中，梗死累及放射冠更为常见。亚急性期和慢性期 ITD+患者的同侧丘脑平均峰度较对侧略有但显著增加，而亚急性期 ITD+和 ITD-患者的各向异性分数均显著增加，慢性期 ITD+患者则显著降低。慢性期 ITD+患者的平均弥散度显著增加。此外，亚急性期 ITD+患者的 AICBF 与 AIMK 和 AIFA 呈负相关，且在调整异常灌注体积和症状出现后时间后，慢性期 ITD+患者的 AIMD 也呈负相关。入院和出院时，ITD+患者的美国国立卫生研究院卒中量表和改良 Rankin 量表评分均较高，且在出院时与临床结局呈独立相关趋势。
动脉自旋标记和弥散峰度成像的联合应用可以揭示大脑中动脉梗死后早期、特定时间的丘脑灌注和弥散变化。与 ITD 相关的低灌注与潜在的微观结构改变显著相关。
