Cerebral Strokes Associated with Pregnancy and the Puerperium

Thirty-one cases of ischaemic cerebral stroke occurring in association with childbirth were fully investigated. The pathological basis of non-haemorrhagic carotid territory strokes in pregnant or puerperal women proved to be similar to that in non-pregnant women of the same age group. Over 70% were due to occlusive cerebral arterial disease or ischaemic lesions unrelated to thrombosis of the intracranial venous system. Comparisons are made with some other reported series in which only a minority of the patients were investigated by angiography, but in which intracranial venous occlusion was assumed to be the primary lesion. It seems likely that many of these patients may also have suffered arterial rather than venous lesions.     

Elevated Intracranial Pressure and Cerebral Edema following Permanent MCA Occlusion in an Ovine Model

Introduction

Malignant middle cerebral artery (MCA) stroke has a disproportionately high mortality due to the rapid development of refractory space-occupying cerebral edema. Animal models are essential in developing successful anti-edema therapies; however to date poor clinical translation has been associated with the predominately used rodent models. As such, large animal gyrencephalic models of stroke are urgently needed. The aim of the study was to characterize the intracranial pressure (ICP) response to MCA occlusion in our recently developed ovine stroke model.

Materials and Methods

30 adult female Merino sheep (n = 8–12/gp) were randomized to sham surgery, temporary or permanent proximal MCA occlusion. ICP and brain tissue oxygen were monitored for 24 hours under general anesthesia. MRI, infarct volume with triphenyltetrazolium chloride (TTC) staining and histology were performed.

Results

No increase in ICP, radiological evidence of ischemia within the MCA territory but without space-occupying edema, and TTC infarct volumes of 7.9+/-5.1% were seen with temporary MCAO. Permanent MCAO resulted in significantly elevated ICP, accompanied by 30% mortality, radiological evidence of space-occupying cerebral edema and TTC infarct volumes of 27.4+/-6.4%.

Conclusions

Permanent proximal MCAO in the sheep results in space-occupying cerebral edema, raised ICP and mortality similar to human malignant MCA stroke. This animal model may prove useful for pre-clinical testing of anti-edema therapies that have shown promise in rodent studies.     

Recent Observations on Mesenchymal Tumours in Adults and Children

Recognition of the types and characteristics of mesenchymal tumours is important, since each type has biological features peculiar to itself that govern its growth and behaviour and it is essential to know these if treatment is to be effectual. Because many differentiated cell types are capable of acting as facultative fibroblasts, histological diagnosis is often in error. It has been found that no matter how bizarre a tumour may appear, if explanted in vitro, the cells will betray their true nature. By this means the various mesenchymal tumour types have been classified, many examples collected and followed up and their biological potentialities recorded. In more recent studies these uncommon tumours in children have been studied and many of them found to be less malignant than in adults. New varieties of mesenchymal tumours have been discovered in recent years, such as pseudosarcomatous fasciitis, elastofibroma dorsi, and bizarre variants of smooth muscle tumour.     

A Biomechanical Model of Tumor-Induced Intracranial Pressure and Edema in Brain Tissue

Brain tumor growth and tumor-induced edema result in increased intracranial pressure (ICP), which, in turn, is responsible for conditions as benign as headaches and vomiting or as severe as seizures, neurological damage, or even death. Therefore, it has been hypothesized that tracking ICP dynamics may offer improved prognostic potential in terms of early detection of brain cancer and better delimitation of the tumor boundary. However, translating such theory into clinical practice remains a challenge, in part because of an incomplete understanding of how ICP correlates with tumor grade. Here, we propose a multiphase mixture model that describes the biomechanical response of healthy brain tissue—in terms of changes in ICP and edema—to a growing tumor. The model captures ICP dynamics within the diseased brain and accounts for the ability/inability of healthy tissue to compensate for this pressure. We propose parameter regimes that distinguish brain tumors by grade, thereby providing critical insight into how ICP dynamics vary by severity of disease. In particular, we offer an explanation for clinically observed phenomena, such as a lack of symptoms in low-grade glioma patients versus a rapid onset of symptoms in those with malignant tumors. Our model also takes into account the effects tumor-derived proteases may have on ICP levels and the extent of tumor invasion. This work represents an important first step toward understanding the mechanisms that underlie the onset of edema and ICP in cancer-afflicted brains. Continued modeling effort in this direction has the potential to make an impact in the field of brain cancer diagnostics.     

神经电生理在颅内动脉瘤夹闭术中联合颅内压、脑灌注压监测的应用效果研究

摘要 目的：探讨神经电生理在颅内动脉瘤夹闭术中联合颅内压（ICP）、脑灌注压（CPP）监测的应用效果。方法：选取2018年12月～2020年1月我院进行开颅手术治疗的颅内动脉瘤患者60例,采用简单随机化分组方法分为两组,每组30例。对照组实施颅内动脉瘤夹闭手术,观察组在对照组基础上,术中应用神经电生理、ICP、CPP监测。比较两组动脉瘤夹闭情况,术后第1 d新发神经功能缺损情况,术前、术后1 d、术后3个月格拉斯哥昏迷评分（GCS）、美国国立卫生研究院脑卒中量表（NIHSS）评分及术后3个月预后优良率。结果：两组动脉瘤均完全夹闭,观察组术后第1 d新发神经功能缺损率6.67%（2/30）低于对照组的26.67%（8/30）（P＜0.05）;术后1 d观察组GCS评分高于对照组,NIHSS评分低于对照组（P＜0.05）;排除失访病例后,观察组术后3个月GOS分级、mRS分级优良率分别为88.89%、88.89%,与对照组的88.00%、84.00%比较,差异无统计学意义（P＞0.05）。结论：采用神经电生理联合ICP、CPP监测,能够实时掌握颅内动脉瘤夹闭术患者脑组织血流情况,根据监测结果及时采取相应干预措施,可预防不可逆的脑缺血改变,改善术后早期患者意识状态,减少术后早期神经功能缺损的发生。     

重度颅脑损伤合并神经原性肺水肿机械通气的观察与护理

目的：探讨重型颅脑损伤合并神经原性肺水肿（NPE）病人机械通气的护理经验,提高此类病人的治疗成功率。方法：回顾性分析2000年～2007年18例颅脑损伤患者合并NPE的临床护理资料,对这些患者进行了机械通气治疗,观察和总结护理的临床效应。结果：18例患者中肺水肿消退11例,死亡7例。11例存活患者经过随访,死亡4例,植物生存1例,重残1例,中残2例,好3例。结论：重型颅脑损伤合并NPE预后不良,死亡率高;机械通气是治疗NPE的有效方法,正确积极的护理可提高患者的治愈率。     

Ornithine Decarboxylase Activity and Edema Formation in Cerebral Ischemia of Conscious Gerbils

Abstract: General anesthetic agents often affect the biochemical and physiologic changes triggered by cerebral ischemia. This study examined the regional activities of ornithine decarboxylase (ODC) in gerbils subjected to 5 min of bilateral carotid occlusion without anesthesia. At 2, 4, and 6 h of reperfusion, significant ODC activity was observed in both the cortex and the hippocampus. Pretreatment with α-difluoromethylornithine (DFMO) significantly blocked the ODC activity at 2, 4, and 6 h. Significant edema formation was found at 2, 4, and 6 h. At 2 h, edema formation was unaffected by administration of DFMO. However, DFMO treatment reduced later edema formation at 4 and 6 h. These results demonstrate that ODC activity and edema formation are delayed in gerbils after the induction of transient ischemia even with the removal of anesthetic agents and their potentially protective effects. These findings suggest that ODC activity and its induction of delayed cerebral edema are specific to cerebral ischemia and not to an anesthetic effect. DFMO treatment reduced both the ODC activity and edema formation, indicating a role for polyamines in postischemic edema formation.     

伽玛刀治疗术后顽固性脑水肿的临床分析

目的:探讨伽玛刀治疗术后顽固性脑水肿发生的临床特点和相关影响因素。方法:总结432例颅内病变经伽玛刀治疗患者,发生顽固性脑水肿87例,以年龄,性别,病灶部位,90%病灶容积的边缘剂量,病灶的平均直径,病灶与正常脑组织的关系作为影响因素,分析伽玛刀治疗术后顽固性脑水肿的相关性。结果:伽玛刀治疗术后顽固性脑水肿的总发生率20.1%,其中以脑内动静脉畸形发生率最高,达41.9%;脑水肿发生率与年龄,病灶部位,90%病灶容积的边缘剂量,病灶平均直径,病灶与正常脑组织关系等因素密切相关。结论:伽玛刀治疗术后顽固性脑水肿发生率较高,值得临床重视。     

Effects of Dexamethasone and Cox Inhibitors on Intracranial Pressure and Cerebral Perfusion in the Lipopolysaccharide Treated Rats with Hyperammonemia

IntroductionSystemic inflammation may affect the brain by aggravating the stage of encephalopathy and increasing intracranial pressure (ICP) especially if liver insufficiency with hyperammonemia is present. The aim of this study was to determine if the influence of concomitant hyperammonemia and lipopolysaccharide (LPS) on the brain can be prevented by dexamethasone and cyclooxygenase (COX) inhibitors.MethodFifty-four male Wistar rats, 6 in each group, were divided into the following groups: Saline+saline; LPS (2mg/kg)+saline; LPS+indomethacin (10mg/kg); LPS+diclofenac (10mg/kg); LPS+dexamethasone (2mg/kg) in experiment A. Experiment-B included the following groups: LPS+NH3 (140μmol/kg/min)+saline; LPS+NH3+indomethacin; LPS+NH3+diclofenac and LPS+NH3+dexamethasone. ICP was monitored via a catheter placed in cisterna magna and changes in CBF were recorded by laser Doppler flowmetry.ResultsLPS with and without NH3 induced a similar increase in plasma 6-keto-prostaglandin-F_1α (6-keto-PGF_1α) concentration together with a concomitant rise in CBF and ICP. Indomethacin and diclofenac prevented the increase in ICP by LPS alone, and with the addition of NH3 the increase in both CBF and ICP, which was associated with a decrease in 6-keto-PGF_1α. Dexamethasone only reduced the LPS induced increase in ICP but not CBF, and partly the 6-keto-PGF_1α plasma concentration in the combined setup.ConclusionThese data indicate that activation of cycloooxygenases is of central importance for development of cerebral hyperemia and high ICP during concomitant systemic inflammation and hyperammonemia.     

微创颅内血肿清除术治疗高血压脑出血的效果分析

目的:探讨微创颅内血肿清除术在高血压脑出血治疗中的应用效果。方法:选择我院收治的80例高血压脑出血患者(2014年12月至2015年12月),通过随机数字表将其分为实验组和对照组。在患者知情同意基础上,实验组患者(42例)采用微创颅内血肿清除术进行治疗,而对照组患者(38例)使用开颅血肿清除术进行治疗。观察并比较两组患者治疗前后颅内压、GCS评分(格拉斯哥昏迷评分)、神经功能,同时对两组患者治疗有效性以及安全性进行评价。结果:治疗前,两组患者颅内压、神经功能以及GCS评分无明显差异性(P0.05),而治疗后,实验组患者上述指标值明显优于对照组,且差异性明显(P0.05)。实验组患者总有效率明显高于对照组(P0.05),而不良反应发生率却低于对照组(P0.05)。结论:颅内血肿清除术治疗高血压脑出血不仅能有效降低颅内压,改善患者神经功能及其昏迷症状,并且安全性较高。