From the Department of Neurology, John Hunter Hospital (A.B., T.L., C.G.-E., V.K., C.R.L., M.P.) and Hunter Medical Research Institute (A.B., T.L., C.G.-E., E.H., V.K., C.R.L., M.P.), University of Newcastle, New South Wales, Australia; Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Lausanne, Switzerland (B.M.); Department of Radiology, CHUV, Lausanne, Switzerland (B.M.); and LTS5, EPFL, Lausanne, Switzerland (B.M.).
Stroke. 2018 Feb;49(2):384-390. doi: 10.1161/STROKEAHA.117.019276. Epub 2018 Jan 4.
Transient ischemic attack (TIA) initiates an ischemic cascade without resulting in frank infarction and, as such, represents a novel model to study the effects of this ischemic cascade and secondary neurodegeneration in humans.
Patients with suspected TIA underwent acute brain perfusion imaging, and those with acute ischemia were enrolled into a prospective observational study. We collected baseline and 90-day magnetic resonance imaging, including MP-RAGE (high-resolution T1 sequence) and cognitive assessment with the Montreal Cognitive Assessment. Brain morphometry and within patient statistical analysis were performed to identify changes between baseline and 90-day imaging and clinical assessments.
Fifty patients with TIA with acute perfusion lesions were studied. All patients experienced a decrease in global cortical gray matter (=0.005). Patients with anterior circulation TIA (n=31) also had a significant reduction in the volume of the pons (<0.001), ipsilesional parietal lobe (<0.001), occipital lobe (=0.002), frontal lobe (<0.001), temporal lobe (=0.003), and thalamus (=0.016). Patients with an anterior perfusion lesion on acute imaging also had a significant decrease in Montreal Cognitive Assessment between baseline and day 90 (=0.027), which may be related to the volume of thalamic atrophy (=0.28; =0.009).
In a prospective observational study, patients with TIA confirmed by acute perfusion imaging experienced a significant reduction in global gray matter and focal structural atrophy related to the area of acute ischemia. The atrophy also resulted in a proportional decreased cognitive performance on the Montreal Cognitive Assessment. Further studies are required to identify the mechanisms of this atrophy.
短暂性脑缺血发作（TIA）会引发缺血级联反应，但不会导致明显的梗死，因此可作为研究人类该缺血级联反应及继发神经退行性变的新型模型。
疑似 TIA 患者行急性脑灌注成像，且存在急性缺血的患者被纳入前瞻性观察研究。我们收集基线和 90 天的磁共振成像，包括 MP-RAGE（高分辨率 T1 序列）和蒙特利尔认知评估的认知评估。进行脑形态计量学和患者内统计分析，以确定基线和 90 天影像学及临床评估之间的变化。
50 例 TIA 伴急性灌注病灶患者参与研究。所有患者的全脑皮质灰质体积均减少（=0.005）。前循环 TIA（n=31）患者的脑桥体积（<0.001）、对侧顶叶（<0.001）、枕叶（=0.002）、额叶（<0.001）、颞叶（=0.003）和丘脑（=0.016）体积也显著减少。急性影像学检查存在前循环灌注病灶的患者，在基线和第 90 天之间的蒙特利尔认知评估也显著下降（=0.027），这可能与丘脑萎缩体积相关（=0.28；=0.009）。
在一项前瞻性观察研究中，经急性灌注成像证实的 TIA 患者经历了全脑灰质和与急性缺血区相关的局灶性结构萎缩的显著减少。这种萎缩还导致蒙特利尔认知评估的认知表现呈比例下降。需要进一步研究来确定这种萎缩的机制。
