Posterior leukoencephalopathy without severe hypertension - Utility of diffusion-weighted MRI
Posterior leukoencephalopathy without severe hypertension - Utility of diffusion-weighted MRI
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DOI：
10.1212/wnl.51.5.1369
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发表时间：
1998-11-01
期刊：
影响因子：
9.9
通讯作者：
Koroshetz, WJ
中科院分区：
文献类型：
--
作者：
Ay, H;Buonanno, FS;Koroshetz, WJ
目的：标准MRI证实了后部白质脑病综合征（PLES）的诊断，最近与越来越多的医疗条件。在PLES中，Ta加权MRI显示高信号从后部脑区域扩散;病理生理学仍然是神秘的。在急性情况下，弥散加权成像（DWI），而不是标准的MR成像，可以区分缺血性损伤与已知引起血管源性脑水肿的条件。DWI在了解PLES的病理生理学和诊断以前没有已知危险因素的患者方面具有潜在价值。研究方法：对3例因其他疾病住院治疗的神经系统综合征伴PLES的女性患者进行了系列CT和MRI研究（包括DWI、表观扩散系数[ADC]图，在一种情况下，还进行了灌注加权成像）。结果：没有患者先前描述过PLES的危险因素;所有患者的血压仅轻度升高。MRI显示大脑后部大的异常T2高信号区，ADC图上相应的高信号-信号特征主要与血管源性水肿一致。还有一个较小的斑片状后皮质区域，ADC降低，DWI明亮，与梗死一致，另一个区域的大面积区域急剧转换为缺血模式。结论：ADC图和DWI可以成功区分PLES和早期脑缺血，从而在治疗决策中发挥关键作用。PLES与比以前报道的更广泛的条件相关，并且并不总是可逆的。高信号DWI信号在患者的综合征可能标志着一个组织阶段的永久性脑损伤。
Objective: Standard MRI confirms the diagnosis of posterior leukoencephalopathy syndrome (PLES), recently associated with an increasing number of medical conditions. In PLES, Ta-weighted MRI demonstrates hyperintensity spreading out from posterior brain regions; the pathophysiology remains mysterious. In the acute setting, diffusion-weighted imaging (DWI), but not standard MR imaging, can distinguish ischemic injury from those conditions known to cause vasogenic brain edema. DWI is potentially valuable in understanding the pathophysiology of PLES and in diagnosing patients who do not have previously known risk factors. Methods: Serial CT and MRI studies (including DWI, apparent diffusion coefficient [ADC] maps, and, in one instance, perfusion-weighted imaging) were performed in three female patients with a neurologic syndrome consistent with PLES while hospitalized for treatment of other conditions. Results: None of the patients had previously described risk factors for PLES; all had only mild elevations in blood pressure. MRI showed large, abnormal, T2 hyperintense regions in the posterior cerebrum with corresponding hyperintensity on ADC maps-signal characteristics predominantly consistent with vasogenic edema. There were also smaller patchy posterior cortical regions with decreased ADC and bright DWI consistent with infarction in one, and dramatic conversion of a large region to an ischemic pattern in another. Conclusions: ADC maps and DWI can successfully differentiate PLES from early cerebral ischemia, thus playing a pivotal role in treatment decisions. PLES is associated with a wider variety of conditions than has been previously reported and is not always reversible. Hyperintense DWI signal in patients with the syndrome likely marks a tissue stage of permanent brain injury.