Schneider J P, Krohmer S, Günther A, Zimmer C
Klinik und Poliklinik für Diagnostische und Interventionelle Radiologie, Abt. Neuroradiologie, Universitätsklinikum Leipzig AöR.
Rofo. 2006 Jun;178(6):618-26. doi: 10.1055/s-2006-926631. Epub 2006 May 15.
In the nine years since the posterior reversible (leuc) encephalopathy syndrome (PRES) was first described, a number of causes have been under discussion. These not only include arterial hypertension, i. e. hypertensive crises, but also various toxic substances, i. e. immunosuppressive or chemotherapeutic agents, that are responsible for the formation of the symptoms and characteristic MR tomographic brain findings.
Initial and follow-up MRI examinations of 8 patients were analyzed. All patients had acute neurological symptoms (headaches, seizures, visual disorders and vigilance disturbances) together with a detectable hypertensive crisis.
MRI disclosed increased signal intensity in subcortical and some cortical lesions in all patient FLAIR sequences. These changes were particularly extensive in the posterior circulation (occipital, cerebellum and brain stem) although they were also detected in brain areas supplied by the carotid artery. However, a cytotoxic genesis of the changes was ruled out in each patient by means of a normal DWI. Furthermore, when the blood pressure was normalized, reversibility of the lesions as proof of the diagnosis was detectable.
The imaging findings can be typically analyzed as a predominantly posterior distribution of encephalopathic lesions with a high probability of reversibility after lowering blood pressure was patients suffering from a critical increase in blood pressure with corresponding neurological symptoms. The exact pathophysiology remains unclear, but the cause currently most favored is a vasculopathy of the posterior circulation due to diminished adrenergic autoregulation in combination with a dysfunction of the endothelial cells. In conclusion, we suggest designating this subpopulation from the non-uniform pool of patients with posterior (leuc) encephalopathy as "hypertensive encephalopathy". "Hypertensive encephalopathy" has to be distinguished from "toxic encephalopathy", particularly due to different therapeutic and prognostic consequences.
自首次描述后部可逆性（白质）脑病综合征（PRES）以来的九年里，人们一直在讨论多种病因。这些病因不仅包括动脉高血压，即高血压危象，还包括各种有毒物质，即免疫抑制剂或化疗药物，它们是症状形成和脑部磁共振断层扫描特征性表现的原因。
分析了8例患者的初次及随访磁共振成像（MRI）检查结果。所有患者均有急性神经症状（头痛、癫痫发作、视觉障碍和意识障碍）以及可检测到的高血压危象。
MRI显示所有患者的液体衰减反转恢复（FLAIR）序列中皮质下和部分皮质病变信号强度增加。这些变化在后循环（枕叶、小脑和脑干）尤为广泛，尽管在颈动脉供血区域也能检测到。然而，通过正常的扩散加权成像（DWI）排除了每位患者病变的细胞毒性起源。此外，当血压恢复正常时，病变的可逆性可作为诊断依据被检测到。
对于血压急剧升高并伴有相应神经症状的患者，影像学表现通常可分析为以脑病性病变主要分布于后部且血压降低后具有高度可逆性为特征。确切的病理生理学尚不清楚，但目前最受青睐的病因是后循环血管病变，这是由于肾上腺素能自动调节减弱以及内皮细胞功能障碍共同作用所致。总之，我们建议将后部（白质）脑病患者这一异质性群体中的这一亚群称为“高血压脑病”。“高血压脑病”必须与“中毒性脑病”相区分，尤其是考虑到不同的治疗和预后结果。
