1、Unilateral optic neuropathy following subdural hematoma: a case report硬膜下血肿后出现的单侧视神经病变：1 例病案报道Alexandra Kretz1 , Christoph Preul1 , Hans-Joerg Fricke2 , Otto W Witte1 and Christoph Terborg3 1 Department of Neurology, University of Jena Medical School, Erlanger Allee 101, Jena D-07747, Germany2 Depar
2、tment of Internal Medicine, Haemato-Oncology, University of Jena Medical School, Erlanger Allee 101, Jena D-07747, Germany3 Department of Neurology, Asklepios Klinik St. Georg, Lohmhlen Str. 5, Hamburg D-20099, Germanyauthor email corresponding author emailJournal of Medical Case Reports 2010, 4:19d
3、oi:10.1186/1752-1947-4-19The electronic version of this article is the complete one and can be found online at:http:/ November 2009Accepted: 22 January 2010Published: 22 January 2010 2010 Kretz et al; licensee BioMed Central Ltd.This is an Open Access article distributed under the terms of the Creat
4、ive Commons Attribution License (http:/creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.AbstractIntroductionUnilateral optic neuropathy is commonly due to a prechiasmatic affliction of the
5、 anterior visual pathway, while losses in visual hemifields result from the damage to brain hemispheres. Here we report the unusual case of a patient who suffered from acute optic neuropathy following hemispherical subdural hematoma. Although confirmed up to now only through necropsy studies, our ca
6、se strongly suggests a local, microcirculatory deficit identified through magnetic resonance imaging in vivo.Case presentationA 70-year-old Caucasian German who developed a massive left hemispheric subdural hematoma under oral anticoagulation presented with acute, severe visual impairment on his lef
7、t eye, which was noticed after surgical decompression. Neurologic and ophthalmologic examinations indicated sinistral optic neuropathy with visual acuity reduced nearly to amaurosis. Ocular pathology such as vitreous body hemorrhage, papilledema, and central retinal artery occlusion were excluded. A
8、n orbital lesion was ruled out by means of orbital magnetic resonance imaging. However, cerebral diffusion-weighted imaging and T2 maps of magnetic resonance imaging revealed a circumscribed ischemic lesion within the edematous, slightly herniated temporomesial lobe within the immediate vicinity of
9、the affected optic nerve. Thus, the clinical course and morphologic magnetic resonance imaging findings suggest the occurrence of pressure-induced posterior ischemic optic neuropathy due to microcirculatory compromise.ConclusionAlthough lesions of the second cranial nerve following subdural hematoma
10、 have been reported individually, their pathogenesis was preferentially proposed from autopsy studies. Here we discuss a dual, pressure-induced and secondarily ischemic pathomechanism on the base of in vivo magnetic resonance imaging diagnostics which may remain unconsidered by computed tomography.I
11、ntroductionUnilateral optic neuropathy (ON) following subdural hematoma has been confirmed by necropsy studies. In these studies, microcirculatory compromise of the optic nerve was proven as a pathogenic mechanism 1. In this case report, diffusion-weighted images (DWI) of magnetic resonance imaging
12、(MRI) scans showed signal alteration in the ipsilateral optic nerve as a strong evidence for the development of microvascular deficit. Thus, our case is in line with results from autopsies. To the best of our knowledge, this is the first case presentation that demonstrates microvascular impairment w
13、ith optic neuropathy in vivo.前言尸检研究已证实硬膜下血肿后可出现单侧视神经病变(optic neuropathy，ON)。这些研究证明视神经的微循环损害是其致病机制 1。本例磁共振成像(magnetic resonance imaging，MRI)扫描的弥散加权成像(diffusion-weighted images，DWI)显示同侧视神经的信号发生改变，为微血管缺陷进展的有力证据，因此本病例符合尸检研究结果。据我们所知，这是首例说明体内视神经病变微血管损害的病案报道。Case presentationA 70-year-old Caucasian man of
14、German nationality receiving warfarin therapy for the primary prevention of chronic atrial fibrillation was admitted to our hospital due to symptoms of a coronary syndrome. An initial international normalized ratio (INR) of 1.7 was elevated to therapeutic ranges (INR = 2.5). Three days later, the pa
15、tient was found comatose after a first-ever generalized seizure. Cerebral computed tomography (CT) revealed a subdural hematoma measuring 16 mm at its maximum thickness and covering almost the entire left convexity which caused a massive midline shift (Figure 1A). Rapid cerebral MRI of the same day
16、depicted a beginning ipsilateral uncal herniation towards the chiasmatic cistern (Figure 1B). Immediately after INR normalisation, surgical evacuation of the subdural hematoma and decompressive craniectomy were performed without any complications.病情介绍一位服用华法林作为慢性房颤初级预防的 70 岁的男性德国籍白种人因发生冠状动脉综合征症状入住本院。
17、国际标准化比率(international normalized ratio， INR)由最初的 1.7 升高至治疗范围(INR = 2.5)。3 天后，患者在第一次癫痫大发作后处于昏迷状态。脑计算机体层成像 (computed tomography，CT) 显示出最大厚度为 16mm 的硬膜下血肿，几乎 覆盖整个左侧大脑凸面，并引起大范围的中线移位 (Figure 1A)。当天行快速脑 MRI 检查，发现起自同侧钩回疝向交叉池的颞叶沟回疝 (Figure 1B)。INR 正常化后立即行硬膜下血肿的手术清除和去骨瓣减压术，无并发症发生。Figure 1. Computed tomography
18、 of subdural hematoma and cerebral magnetic resonance imaging depicting early uncal herniation and mesiotemporal ischemic brain injury. (A) Preoperative cranial computed tomography scan reveals space-occupying subdural hematoma covering the left convexity. The hematoma causes a considerable midline
19、shift at the level of the lateral ventricles. (B) Early diffusion- weighted magnetic resonance imaging (diffusion-weighted imaging) depicts a slight uncal herniation and a midline deviation at the level of the chiasmatic basal cistern. (C) Diffusion-weighted imaging sequences four days after surgery
20、 show circumscribed signal hyperintensity in the left uncal region indicative of local ischemic injury. Note the close anatomic proximity to the distal prechiasmatic course of the left optic nerve. (D) Corresponding hyperintensity in T2-weighted images indicates edema of the left temporomesial lobe
21、that is consecutive to hypoperfusion and residual to preceding uncal herniation.图 1。硬膜外血肿的计算机体层成像和脑磁共振成像显示出早期颞叶沟回疝和近颞叶缺血性脑损伤. (A)术前头颅计算机体层成像扫描可见覆盖左侧大脑凸面的占位性硬膜下血肿。血肿导致侧脑室层面相当大的中线移位。(B) 交叉基底池层面的早期弥散加权磁共振成像（弥散加权成像）可见轻微的颞叶沟回疝和中线偏移。(C) 术后 4 天的弥散加权成像序列可见左侧钩回区局限性高信号，提示局部有缺血性损伤。注意其解剖紧靠左侧视神经前交叉行程的远端。(D) T2 加
22、权图像上相应的高信号提示左颞叶内侧水肿，与低灌注相邻，为先前钩回疝的残留。Two days after extubation and recovery from anaesthesia, the patient complained of severe sinistral visual loss. Neurologic and ophthalmologic examinations confirmed a severely reduced visual acuity on his left eye with concomitant afferent pupillary defect. A no
23、rmal vascular fundoscopy and the lack of papilledema led to the working diagnosis of posterior ON. Four days after the surgery, a follow-up DWI of the cerebral MRI (Figure 1C) showed a signal hyperintense lesion within the left lateral, mesiobasal temporal lobe that was immediately adjacent to the d
24、istal prechiasmatic course of the affected optic nerve. Dull signal attenuation in corresponding apparent diffusion coefficient (ADC) maps, and gadolinium enhancement in T1 (not shown) led to the diagnosis of a subacute cerebral ischemic event.拔管后 2 天，患者从麻醉中恢复过来，主诉有严重的左侧视力丧失。神经系统和眼科学检查证实有严重的左眼视力下降伴瞳
25、孔传入缺陷。血管眼底镜检查正常，无视乳状水肿，得出最可能的诊断为后部 ON。手术后 4 天，复查脑 MRI 的 DWI (图 1C)发现左外内侧基底颞叶可见一高信号病变，紧邻受累视神经交叉前行程的远端。相应表观弥散系数(apparent diffusion coefficient，ADC)图中模糊的信号衰减和 T1中的钆增强（未显示）可得出亚急性脑缺血事件的诊断。The corresponding hyperintensity of T2-weighted images indicated focal brain edema in line with regional hypoperfusio
26、n and the preceding uncal shift (Figure 1D). Thus, pathomorphologic and sequence-specific MRI criteria suggest a primary mechanic compression followed by secondary microcirculatory impairment of the afflicted brain area. In support of this hypothesis, DWI alterations were not manifest at the initial
27、 MRI diagnostics. Although not directly proven by MRI but due to its close anatomic course and the temporal coincidence of optic nerve affliction, an equal dual pathomechanism was believed to be the cause of the appearance of ON. Further cerebral or orbital pathologies were not apparent (not shown).
28、 Within weeks, the patient was released for rehabilitation without further visual improvement.T2 加权图像上相应的高信号提示局灶性脑水肿，与区域低灌注和先前的钩回疝改变相符(图 1D)。因此，病理形态学与序列特异性 MRI 标准提示存在原发的机械性压迫后继发的受累脑部的微循环损害。 DWI 的改变未在最初的 MRI 诊断上显示出来支持了这一假设。尽管未直接由 MRI 所证实，但由于其紧靠视神经的解剖行程且和视神经病变存在时间上的一致，故一个平等的双重病理机制被考虑为 ON 出现的原因。进一步的脑部或
29、眶部病变并不明显（未显示）。几周后，患者康复出院，没有明显的视力改善。Discussion讨论To date, only a few cases of ON following subdural hematoma are presented, and their pathomorphologic in vivo findings do not at all elucidate its aetiology. Generally, reports do not present the existence of papilledema or of radiologic in vivo evidenc
30、e of optic nerve compression by mass effects 2. In contrast, autopsy studies confirm optic nerve necrosis that is remote from space occupying lesions 1.迄今为止，仅有为数不多的硬膜下血肿后 ON 病例见诸报道，其体内的病理形态学结果并不能完全解释其病因。一般来讲，这些报告未能说明视乳状水肿的存在或给出视神经受容积效应受压的体内放射学证据2。相反，尸检研究证明远离空间占位性病变的视神经却发生坏死1。The pathophysiology of O
31、N has been discussed in the context of diverse aetiological events, and adequate diagnostic approaches have already been proposed. Table 1 provides an overview of selected publications focussing on key diagnostic means to identify and characterize vascular, mechanical, and pharmacologic aetiologies
32、of ON (Table 1).ON 的病理生理学在多种病因事件中已有讨论，并提出过多种诊断方法。表 1 对集中于识别和定义 ON 血管性、机械性及药理学病因的主要诊断手段的代表性论文作一概述（表 1）。Table 1. Overview of the different aetiologies of optic neuropathy.表 1。视神经病变的不同病因概述At present, only a few cases refer to the diagnostic value of MRI in ON. By means of MRI, unilateral 3 and simultan
33、eous bilateral 4 ischemic ON were diagnosed. It was concluded that DWI and ADC maps of MRI may be useful in detecting ischemia of any white matter tracts that are disparate from the brain and spinal cord. MRI diagnostics may even prove suitable in distinguishing ischemic events from optic neuritis 3
34、, while also providing the opportunity to simultaneously detect anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). Likewise, MRI venography in relation to DWI and ADC maps unequivocally confirmed that ON can be caused by cavernous sinus thrombophlebitis 5.目前，仅有
35、少数的 ON 病例提及 MRI 的诊断价值。通过 MRI 检查，可以诊断单侧3和同时发生的双侧 4缺血性 ON。有人认为， MRI 的 DWI 和 ADC 图在检测来自脑和脊髓不同部位的白质束缺血也许有帮助。MRI 诊断甚至适合用于鉴别视神经炎中的缺血事件3，同时也能为前部缺血性视神经病变(anterior ischemic optic neuropathy，AION)和后部缺血性视神经病变(posterior ischemic optic neuropathy，PION) 的同时检测提供机会。同样，与 DWI 和 ADC 图有关的 MRI 静脉造影明确地证实ON 可由海绵窦血栓性静脉炎所引起
36、 5。Using the MRI technique, we now provide a pathophysiologic insight on ON following space occupying subdural hematoma early in vivo. Radiological signs of herniation were discrete, although highly sensitive MRI revealed a mechanic, pressure-induced brain lesion of the mesiobasal temporal lobe in p
37、roximity to the affected optic nerve. However, focal ischemic injury was missed in detecting basal brain shift by CT. Since MRI pathologies fulfilled the criteria of ischemic compromise, we suggest that the local increase in intracranial pressure (ICP) exceeded the perfusion pressure of both structu
38、res, namely the formation of the uncus and the nearby passing optic nerve. Consistent with this notion of a microcirculatory deficit, the lesion did not follow the characteristic extent of a vascular territory.MRI 技术的应用让我们现在对体内早期空间占位性硬膜下血肿后发生的 ON 有了病理生理上的认识。尽管高敏感的 MRI 在靠近受累视神经的内侧基底颞叶处可显示一个机械的压力所致脑部病
39、变，但疝形成的放射学征象是不连续的。然而，CT 在检测基底部脑改变时却未发现局灶性脑缺血损伤。由于 MRI 病理符合缺血性损害的诊断标准，因此我们提出颅内压(ntracranial pressure，ICP)的局部升高超出了两种结构，即钩回与行经附近视神经的灌注压。与这一微循环缺陷见解相一致的是，病变没有循沿血管分布区的特定范围。ConclusionsWe suggest that rare cases of acute ON following subdural hematoma are due to local pressure-induced optic nerve infarction
40、. This pathomechanism may remain neglected when massive brain shift is lacking or when CT is the only diagnostic means. The use of serial MRI may help balance the discrepancy between the paucity of clinical reports and frequent neuropathological findings of anterior visual pathway damage in space-oc
41、cupying brain injury 1.结论我们提出硬膜下血肿后发生急性 ON 的罕见病例是由于局部压力导致的视神经梗塞。 当缺乏大面积的脑部改变或仅用 CT 作为诊断手段时，这一病理机制可能仍会被忽略。系列 MRI 的应用也许有助于平衡空间占位性脑损伤中前视觉通路损伤临床报告的资料缺乏与常见神经病理检查发现间的差异 1。AbbreviationsADC: apparent diffusion coefficient; AION: anterior ischemic optic neuropathy; CT: computed tomography; DWI: diffusion-wei
42、ghted imaging; FLAIR: fluid attenuated inverse recovery; ICP: intracranial pressure; INR: international normalized ratio; MRI: magnetic resonance imaging; ON: optic neuropathy; PION: posterior ischemic optic neuropathy.ConsentWritten informed consent was obtained from the patient for publication of
43、this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.Competing interestsThe authors declare that they have no competing interests.Authors contributionsAK and CP interpreted the patient data and clinical course rega
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