术后脑梗塞

术后脑梗塞并非罕见,一旦发生患者的预后严重恶化,还易引起医患纠纷.但重要的是至今我们对此没有规范的防治方法.此文回答了常见的有关问题:术后脑梗塞的危险因素、发病率、发病机制、既往有脑血管病患者行择期手术的推荐做法和脑梗塞的早期治疗.     

Dynamic CT scan in cerebral infarction

Forty-two dynamic CT studies were performed on 27 patients with cerebral infarction (11 to 75 years of age), and perfusion patterns of low density areas on plain CT were evaluated. The initial studies were performed 1.5 hours to 60 days after acute onset. In 14 patients, repeat studies were carried out to know how the perfusion pattern changes with time. All scannings were done on the level which includes anterior horns and trigones of lateral ventricle, thalamus, and internal capsules. CT scanners used were SIEMENS SOMATOM 2 and GE CT/T 8800. Procedures were as follows: 65% amidotrizomeglumin (1 ml/kg) was injected over 5 seconds through 18G needle placed in a antecubital vein. Injection of the contrast media was started with initiation of the second scanning. Totally 8 and 10 serial scans were performed, in SOMATOM 2 and CT/T 8800 respectively. Perfusion pattern is evaluated by comparing two time-density curves obtained from low density area on plain CT and the same region of contralateral side. The following results were obtained. The perfusion pattern in the low density area on plain CT varies among patients at any periods after onset, ranging from absent perfusion pattern to hyperfusion pattern. No consistent perfusion pattern was obtained at any given time after onset. Repeat dynamic CT revealed that the perfusion pattern in the low density area changed with time variously. The perfusion pattern or change of perfusion pattern did not correlate with outcome of the patient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Silent cerebral infarction in hemodialysis patients

BACKGROUND: Cerebrovascular diseases are very common in hemodialysis (HD) patients. Silent cerebral infarction (SCI) has not been investigated in HD patients although it may be a significant risk factor for cerebrovascular diseases. HYPOTHESIS: Chronic renal failure may be an independent risk factor for SCI and cerebrovascular diseases. METHODS: Cranial magnetic resonance imaging (MRI) was performed on 123 HD patients without symptomatic cerebrovascular disease and on 52 control subjects. We investigated the prevalence of SCI and performed cross-sectional study using multiple logistic analysis to assess the relationship between SCI and the risk factors. RESULTS: The prevalence of SCI was significantly higher in HD patients than in the healthy control group (60 patients (48.8%) vs. 5 patients (9.6%), chi(2) = 22.4, p < 0.0001). Multiple logistic regression analysis with all subjects showed that independent risk factors of SCI were chronic renal failure, hypertension, smoking and age (R(2) = 0.468, p < 0.0001). In only the HD patient group, age and smoking were shown to be independent risk factors of SCI (R(2) = 0.378, p < 0.0001) while HD duration and hypertension were not. CONCLUSIONS: The findings of the present study indicate that chronic renal failure maintained by hemodialysis increases the prevalence of SCI and that age and smoking habits are also significantly associated with SCI in HD patients.     

Mass effect with cerebral infarction

Opinion statement Despite the intensive care management of patients with large cerebral infarcts, mortality rates remain high. Conservative medical management is largely ineffective in this population. Patients at high risk for the development of massive brain edema can be identified within the first few hours of onset. This is important to remember because therapeutic benefit may require early intervention, before the brain is displaced by edema. Induced moderate hypothermia (328C to 338C) and hemicraniectomy with durotomy or duroplasty are two promising therapeutic strategies that may reduce mortality rates and improve outcomes if they are performed before irreversible brain stem injury occurs.     

MRI of acute cerebral infarction

Sequential changes of magnetic resonance imaging (MRI) in sixteen patients with acute cerebral infarction are studied in comparison with the findings of computed tomography (CT). The sixteen patients were examined within 36 hours from the onset of symptoms on resistive type MRI (0.15T) using T1 weighted image (IR2000/500) and T2 weighted image (SE2000/80), and on CT. In general, large infarcted lesions of the cortex-subcortex seemed to be visualized earlier than small lesions of the basal ganglia and brainstem. In 8 patients, the infarcted lesions were detected on MRI earlier than on CT. For example, early detecting time within 12 hours were 2, 6, 7, and 10 hours after onset. In two patients of this group, lesions were detected on T2-weighted image earlier than on T1-weighted image. In two cases, small lesions of the brainstem were detected only on MRI. The size of abnormal findings gradually developed and reached a maximum on days 5 to 7 sequentially. The difference between infarction and perifocal edema was not clear even on MRI. The changes gradually subsided and assumed a stable size after about 2 months. Contrast enhancement effect was observed in four patients. In two of these cases, the signal intensity of T2-weighted imaging was decreased just at the region which was enhanced with contrast medium. MRI is useful for early diagnosis of ischemic cerebral infarction, and may elucidate some aspects of the pathophysiology of ischemic stroke.     

Clinical analysis of cerebral infarction in children

Six cases of cerebral occlusive disease in children were reported. The cerebral arterial occlusive disease had its onset at the age of less than 4 years, except for one case of a 9 year-old. The causes of occlusion were, trauma in two cases, infectious disease in one case, intraarterial myxoma in one case and an unknown reason in two cases. Initial symptoms were sudden onset of hemiplegia in 5 cases, and headache in one case. Angiography revealed stenosis of the main trunk of the middle cerebral artery, or of the anterior cerebral artery in 4 cases. Angiographical manifestations of stenosis in 4 cases were classified into two types, diffuse stenosis and localized stenosis. No stenotic changes were demonstrated in two cases, in which CT revealed a small low density area in the putamen. Follow up angiogram in three cases revealed improvement of stenosis. Though therapy in all cases was conservative, their prognosis is not so poor as had been considered. As the rate of recanalization in children was assumed to be high as compared with adult cases, it was considered that surgical revascularization in the acute stage had to be undergone very carefully.     

Interhemispheric intracranial pressure gradients in massive cerebral infarction

We report continuous bilateral intracranial pressure (ICP) monitoring immediately after transtentorial herniation in a patient with massive cerebral infarction to: 1) determine presence and time course of compartmental ICP differences, and 2) to study effects of therapy on both hemispheres. A 55-year-old man admitted with watershed infarctions in the left anterior-middle-posterior cerebral arteries distribution. Initial investigations demonstrated highly narrowed left extracranial internal carotid artery. Eight days later he developed unexplained lethargy and anisocoria. Head computerized tomography (CT) showed massive left hemispheric infarction, edema, and midline shift. Bilateral subarachnoid bolts demonstrated equally elevated ICP in both hemispheres. Hyperventilation and osmotic therapy produced near-identical ICP reduction bilaterally with resolution of anisocoria. Later, plateau waves and autonomic instability developed. Shortly before loss of brainstem function, interhemispheric ICP gradients (left greater than right) of 30-40 mm Hg developed. Intracranial pressure did not equalize prior to brain death determination. Bilateral ICP monitoring did not reveal an interhemispheric ICP gradient soon after transtentorial herniation in massive MCA infarction. The presence of interhemispheric ICP gradients in massive stroke remains unproven and further clinical study is necessary.     

Hyperbaric oxygen and cerebral infarction in the gerbil

The effectiveness of hyperbaric oxygen in reducing the incidence of cerebral infarction during the first 36 hours after occlusion of the right common carotid artery was investigated in gerbils. After carotid ligation, the gerbils were divided into four groups: controls, which breathed air at ambient pressure; group 1, which received hyperbaric oxygen at 1.5 atmospheres absolute pressure (ATA) for 36 hours, with a 5-minute, 1.5-ATA air break each hour; group 2, which received hyperbaric oxygen at 1.5 ATA for 1 hour alternating with 1 hour air at 1 ATA, for 36 hours; and group 3, which received hyperbaric oxygen at 1.5 ATA with hourly 5-minute air breaks for 18 hours, and ambient air for the second 18 hours. Neurological evaluations and staining of the brain with tetrazolium revealed the following results at 36 hours after carotid ligation: 72% of the controls had cerebral infarcts; 26% of the gerbils in group 1 had infarcts, but all animals died at 24-36 hours after beginning hyperbaric oxygen exposure from oxygen toxicity; 44% of the gerbils in group 2 had infarcts; 11% of the gerbils in group 3 had infarcts during the first 18 hours after carotid ligation, and no infarcts developed in the 18 hours that followed. Hyperbaric oxygen reduces the incidence of cerebral infarction after carotid artery ligation, presumably by allowing time for collateral circulation to develop.     

脑血流速度对外伤性脑梗塞的预测作用

目的观察重型颅脑外伤术后脑血流动力学指标的时程变化规律,揭示脑血流动力学指标对外伤性脑梗塞的预测价值。方法选取重型颅脑外伤术后患者104例,正常对照组40例,TCD检测大脑前、中、后动脉平均血流速度,对数据进行相关统计分析。结果重型颅脑外伤术后第1天大脑中、前、后动脉平均血流速度明显升高,第3天到达高峰,后逐渐下降,经Mann—Whitney U检验,5个时间点的平均血流速度均显著高于对照组（P〈0．001）。重型颅脑外伤术后第1天、第3天、第5天、第7天和第14天,脑梗塞组大脑前、中、后动脉平均血流速度均明显高于非脑梗塞组（P〈0．05）。ROC曲线辨别了大脑巾、前、后动脉平均血流速度的判定界值,对预测重型颅脑外伤术后外伤性脑梗塞有较高的灵敏度和特异度。大脑中动脉平均血流速度的曲线下面积显著大于大脑前、后动脉平均血流速度的曲线下面积（P〈0．05）。结论脑血管痉挛是颅脑外伤继发性脑损伤的重要危险因素．参与外伤性脑梗塞的病理生理机制,大脑动脉平均血流速度,特别是大脑中动脉平均血流速度可早期预测外伤性脑梗塞的发生．可指导临床,降低颅脑外伤的死亡率和致残率。     

Early carotid endarterectomy after cerebral infarction

The objective of the study was to review our recent experience with carotid endarterectomy performed within 30 days of completed cerebral infarction and to evaluate the role of computed tomographic (CT) scanning in the decision-making process. Twenty-seven of 302 operations (9%) were carried out during the 30-day time period. The mean interval between cerebral infarction and surgery was 14 days. Angiography revealed severe stenosis (greater than 75%) of the internal carotid artery in 19 patients. Severe stenosis with deep ulceration found in 6 patients and moderate stenosis (i.e., 50-75%) with deep ulceration was found in 2 patients. CT scans showed recent infarction in 4 patients and an old subcortical lacune in 2 patients. Twenty-two patients were neurologically stable with mild deficits and showed normal results on a CT scan performed 24 hours or more after the ischemic event. These patients underwent early cerebral angiography and carotid endarterectomy without permanent morbidity or mortality. Two patients with moderate stable neurological deficits and findings of recent infarction on CT scans had uneventful postoperative courses. Five patients who were neurologically unstable underwent surgery. The 2 patients with repeated transient ischemic attacks and normal findings on CT scans had uneventful postoperative courses. Two of the three patients with progressive neurological deficits and CT findings of recent cerebral infarction experienced extension of their infarcts after surgery. One of these patients died. Our personal experience, together with a review of previous reports, indicated that patients who have minimal residual neurological deficits and whose CT scans show normal findings are at low surgical risk, perhaps approaching that of patients with transient ischemic attacks.(ABSTRACT TRUNCATED AT 250 WORDS)     

血液透析患者无症状脑梗塞危险因素的探讨

目的探讨维持性血液透析（CHD）患者发生无症状脑梗塞（SCI）的危险因素。方法对无脑血管疾病症状的115例CHD患者和48例尿毒症非透析患者进行头颅核磁共振成像（MRI）检查,研究SCI的发生率,并使用多元回归分析,探讨CHD患者SCI的危险因素。结果CHD患者SCI的发生率显著高于对照组（分别是46．9％、8．3％,P〈0．01）。对所有受试者进行多元回归分析的结果表明,SCI的危险因素包括：慢性肾衰竭、高血压、吸烟和年龄（R^2=0．54,P〈0．01）。在CHD组,年龄和吸烟是独立危险因素（R^2=0．63,P〈0．01）,而与CHD持续时间无关。结论进行CHD的慢性肾衰竭患者SCI的发生率增加,CHD患者的年龄、高血压和吸烟习惯与SCI有密切关系。     

Silent cerebral infarction predicts vascular events in hemodialysis patients

BACKGROUND: Cardiovascular disease is the leading cause of death in hemodialysis (HD) patients. We have previously reported a higher incidence of silent cerebral infarction (SCI) in HD patients compared with the control group using MRI studies. In the present study, we examined whether or not SCI could predict vascular events in HD patients. METHODS: Cranial magnetic resonance imaging (MRI) was performed on 119 HD patients without symptomatic cerebrovascular disease. SCI was detected by MRI, and the patients were prospectively followed up. The end points of the study were the incidence of major events related to vascular events (cerebral events, cardiac events, and sudden deaths). We investigated the prognostic role of SCI in cerebral, cardiac, and vascular events by using the Kaplan-Meier method and Cox proportional hazards analysis. RESULTS: The prevalence of SCI was 49.6% in HD patients. During a follow-up period of maximum 60 months, vascular events, which included 13 cerebral events, 5 cardiac events, and 3 sudden deaths, occurred in 21 patients. The presence of SCI was predictive for a higher cerebral and vascular morbidity compared to the absence of SCI [18.6% (N= 11) vs. 3.3% (N= 2), P= 0.0169, and 30.5% (N= 18) vs. 5.0% (N= 3), P= 0.0006, respectively]. By multivariate Cox proportional hazards analysis, SCI remained a powerful independent predictor of cerebral and vascular events (hazard ratio for cerebral events 7.33, 95% CI 1.27-42.25: for vascular events 4.48, 95% CI 1.09-18.41). CONCLUSION: The findings of the present study indicate that the presence of SCI is a new risk factor for vascular events in HD patients.     

磁共振扩散加权成像在脑梗死超急性期诊断中的应用

目的：探讨磁共振扩散加权成像在急性脑梗死诊断中的应用价值。方法回顾性分析脑梗死患者60例的临床资料,根据磁共振检查距发病时分为＜6h组,6h～组,24h～组,48～72h组,选取病灶中心以及对应的检测部位5×5像素大小区域,测定器ADC值,计算rADC值。结果不同时间点组内健侧和患侧ADC值比较存在显著差异（P＜0.01）,患侧显著低于健侧。组间ADC值以及rADC值比较差异无统计学意义（P＞0.05）。结论 DWI脑梗死超急性期就能显示出清晰异常信号,对脑梗死超急性期的诊断具有显著临床意义。     

儿童脑梗死临床及MRI表现

目的 观察儿童脑梗死的临床及MRI表现。方法 回顾性分析14例7个月～14岁脑梗死患儿临床及MRI资料,均接受头部常规MRI及弥散加权成像(DWI),11例同时接受MR血管造影(MRA),5例同时接受动脉自旋标记(ASL)灌注成像,观察其相关特点。结果 14例中,5例为先天性心脏病及脑动脉瘤术后,2例脑部外伤,2例颅内病毒感染,1例血管肌纤维发育不良,1例非特异性血管炎,3例病因不明;其中6例病变累及基底核区,4例累及单或双侧脑叶,小脑半球受累2例,脑桥及丘脑受累各1例。常规MRI中,14例病灶T1WI均呈稍低信号、T2WI呈稍高信号,1例基底核区及侧脑室旁梗死区见出血转化,2例液体衰减反转恢复(FLAIR)序列图像示病变周围脑沟内血管扩张;DWI中1例病灶呈低信号外,13例病灶呈高或稍高信号。11例接受MRA,其中6例未见异常、5例脑动脉(椎动脉、基底动脉、大脑后动脉、大脑中动脉、颈内动脉)闭塞或重度狭窄。5例急性及亚急性期患儿接受ASL检查,其中4例病变呈高灌注,1例病变中央呈低灌注、边缘呈高灌注。结论 先天性心脏病术后、脑部外伤及颅内感染是儿童脑梗死常见病因;基底核区及脑叶为儿童...