The validity of a simple clinical classification of acute ischaemic stroke

The aim of the study reported here was to test the validity of a simple clinical classification of acute ischaemic stroke (Oxfordshire Community Stroke Project, OCSP) in predicting the site and size of cerebral infarction on computed tomography (CT). Consecutive patients admitted to hospital with acute ischaemic stroke were prospectively identified and classified into one of four clinical syndromes according to the OCSP classification, blind to the result of CT. The CT brain scans were classified blind to the clinical features into those demonstrating: small, medium or large cortical infarcts; small or large subcortical infarcts in the anterior circulation territory; and posterior cerebral circulation territory infarcts. A total of 108 patients were included. A recent infarct was seen. on the CT scan in 91 patients (84%), and the clinical classification correctly predicted the site and size of the cerebral infarct in 80 of these (88%; 95% confidence interval 77–92%). The positive predictive value was best for large cortical infarcts (0.94) and worst for small subcortical infarcts (0.63). The OCSP clinical classification is a reasonably valid way of predicting the site and size of cerebral infarction on CT and can, therefore, be used very early after stroke onset before the infarct appears on the scan.     

Agreement between the clinical Oxfordshire Community Stroke Project classification and CT findings in Poland

The Oxfordshire Community Stroke Project (OCSP) classification provides a simple means of classifying the clinical syndromes associated with acute stroke. The validity of the classification can depend on many factors. Accuracy and time of the clinical and radiological examination are very important. It was used in the International Stroke Trial (IST). The study was conducted in 467 hospitals in 34 countries. Our aim was to assess how well the OCSP classification could predict infarct site and size on computed tomography (CT) scan when performed in a trial within 48 h after the onset of stroke and the clinical assessment was carried out by different doctors in different hospitals. We examined data on the patients randomized in the IST by the seven participating hospitals in Poland. Patients admitted to the hospital were examined by the doctor on duty. Eight aspects of the neurological deficit present just before randomization were recorded. The computer system in the randomization centre employed a validated algorithm to assign the patient to one of the four infarct syndromes: lacunar syndrome (LACS), partial anterior circulation syndrome (PACS), total anterior circulation syndrome (TACS) and posterior circulation syndrome (POCS). We assessed the localization and extent of the recent infarction on available CT scans and correlated these with the computer-assigned OCSP category. CT scans were available for 558/759 (74%) of the patients randomized in Poland. In 458 (82%) of cases, CT was carried out in the first 24 h after the onset of stroke. In 444 (80%) scans, a recent infarct was visible. These radiological lesions were appropriate to the clinical classification in 56% of patients with TACS, 73% with PACS, 61% with LACS and 59% with POCS. In Polish centres in IST, amongst the patients with infarction visible on CT, the OCSP subtype predicted the size and site of the infarct in about two-thirds of cases. These data suggest that, provided its limitations are taken into account, the classification can be usefully applied in multicentre clinical trials (or epidemiological studies) and to aspects of the routine clinical care of patients with acute stroke.     

How well does the Oxfordshire Community Stroke Project classification predict the site and size of the infarct on brain imaging?

OBJECTIVES: The Oxfordshire Community Stroke Project (OCSP) classification is a simple clinical scheme for subdividing first ever acute stroke. Several small studies have shown that when an infarct is visible on CT or MRI, the classification predicts its site in about three quarters of patients. The aim was to further investigate this relation in a much larger cohort of patients in hospital with ischaemic stroke. METHODS: Between 1994 and 1997, inpatients and outpatients with ischaemic stroke were assessed by one of several stroke physicians who noted the OCSP classification. A neuroradiologist classified the site and extent of recent infarction on CT or MRI. RESULTS: Of 1012 patients with ischaemic stroke, 655 (65%) had recent visible infarcts. These radiological lesions were appropriate to the clinical classification in 69/87 (79%) patients with a total anterior circulation syndrome, 213/298 (71%) with a partial anterior circulation syndrome, 105/144 (73%) with a lacunar syndrome, and 105/126 (83%) with a posterior circulation syndrome. Overall, 75% of patients with visible infarcts were correctly classified clinically. If patients without a visible infarct did have an appropriate lesion in the brain (best case), the classification would have correctly predicted its site and size in 849/1012 (84%) patients, compared with only 492/1012 (49%) in the worst case scenario. CONCLUSION: The OCSP classification predicted the site of infarct in three quarters of patients. When an infarct is visible on brain imaging, the site of the infarct should guide the use of further investigations, but if an infarct is not seen, the OCSP classification could be used to predict its likely size and site.     

Does diabetes mellitus affect the course and prognosis of ischemic stroke?

Although diabetes is a well-known risk factor for ischemic stroke, its role in ischemic stroke outcome has not been clarified yet. Stroke subtypes according to the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification, history of hypertension, serum glucose levels, blood pressure and OCSP (Oxfordshire Community Stroke Project) clinical types of admission, the presence of infections and seizures in the acute phase of illness, duration of hospitalisation, early and in-hospital mortality in diabetics and non-diabetic stroke patients were studied. CT scans in both groups were analysed by the size, localisation and number of ischemic foci. Significant differences were found only as regards the history of hypertension, as well as glucose levels and blood pressure on admission. The incidence of arterial hypertension prior to ischemic stroke was higher in the diabetic group. These patients had significantly higher blood glucose, systolic and diastolic blood pressure level on admission than had the non-diabetic group. No differences were found between the two groups on any other analysed variables. Our observations suggest that diabetes has no effect on the course and outcome of ischemic stroke.     

Relationship between pattern of intracranial artery abnormalities on transcranial doppler and Oxfordshire Community Stroke Project clinical classification of ischemic stroke

BACKGROUND AND PURPOSE: The Oxfordshire Community Stroke Project (OCSP) devised a simple classification for acute stroke based on clinical features only, which is of value in predicting prognosis. We investigated whether the pattern of intracranial vascular abnormalities is related to the clinical syndrome. METHODS: Patients with acute ischemic stroke were classified by a stroke physician as having total or partial anterior circulation infarct (TACI or PACI, respectively), lacunar infarct (LACI), or posterior circulation infarct (POCI). Color-coded power transcranial Doppler was done whenever possible. Intracranial arterial velocities were compared in the 4 subtypes of ischemic stroke after adjustment for age and time to transcranial Doppler. RESULTS: Middle cerebral artery velocity was abnormal (hyperemia, reduced velocity, occlusion, or focal stenosis) in 38 of 69 TACIs (55%), 50 of 171 PACIs (29%), and 20 of 236 LACIs or POCIs (8%) (P<0.001). Velocity in the A1 segment of the anterior cerebral artery was reversed in 12 of 69 TACIs (17%), 20 of 171 PACIs (12%), and 8 of 236 LACIs or POCIs (3%) (P<0.001). Basilar artery velocity was abnormal in 8 of 121 POCIs (7%) compared with 5 of 355 (1%) of the other subtypes (P=0.005). Vertebral artery velocity was abnormal (reduced velocity, occlusion, stenosis) in 20 of 121 POCIs (17%) compared with 20 of 355 others (6%) (P=0.01). CONCLUSIONS: Intracranial arterial abnormalities were related to OCSP clinical subtype. Therefore, it is possible to stratify patients according to OCSP classification in trials of new treatments in which treatment effectiveness may depend on the underlying pattern of arterial pathology and before any arterial imaging is available.     

Combined carotid and transcranial ultrasound findings compared with clinical classification and stroke severity in acute ischemic stroke

BACKGROUND: The aim of this study was to assess the association between cerebral hemodynamics and the clinical picture as defined by the Oxfordshire Community Stroke Project (OCSP) classification, as well as the clinical severity as defined by the National Institute of Health Stroke Scale (NIHSS) within the first 6 h of an acute middle cerebral artery (MCA) stroke onset. METHODS: 70 unselected patients were grouped according to the OCSP classification and NIHSS. All patients immediately had extracranial and transcranial Doppler (TCD) ultrasound examinations. RESULTS: In the study population as a whole, there was a significant association between intracranial vascular pathology and the OCSP classification (p<0.001) as well as the NIHSS score (p<0.001). In patients with severe stroke, however, TCD demonstrated the hypothesized proximal MCA(1) occlusion in only 34% of patients with an OCSP-defined total anterior circulation syndrome and in 42% of patients with an NIHSS score of >or=15. In moderate stroke, the OCSP classification was misleading in almost half of the patients with a partial anterior circulation syndrome, i.e. a hypothesized distal MCA(2) occlusion suitable for thrombolysis. CONCLUSIONS: Neither the OCSP classification nor the NIHSS grading provided reliable information about the site or presence of intracranial arterial occlusion in acute stroke within the first 6 h after stroke onset in the individual patient. The results of this study strongly suggest that selection of acute ischemic stroke patients for thrombolysis should also include an assessment of cerebral hemodynamics.     

Predictive value of clinical lacunar syndromes for lacunar infarcts on magnetic resonance brain imaging

OBJECTIVE: We prospectively investigated the predictive value of clinical and CT-supported lacunar syndromes for lacunar infarcts on magnetic resonance (MR) brain imaging. PATIENTS AND METHODS: The 54 prospective, consecutive patients had clinical lacunar syndromes of acute onset and early computed tomography (CT; on admission day, i.e. < or =48 h after onset of symptoms) showing either a small deep infarct or no corresponding lesion. Taking MR (at day 2 to 4 after admission) as the gold standard, the positive predictive value of the CT-supported clinical syndrome for corresponding lacunar lesions was calculated. RESULTS: In 27 (50%) patients, early CT showed a lacunar infarct corresponding to the clinical syndrome, a further 27 (50%) patients had no fresh ischemic lesion. In 51 patients (94%), MR showed a recent lacunar infarct (hyperintense lacune in T2-weighted scans, no demarcation on T1-weighted scans and/or positive gadolinium-enhancement) corresponding to the clinical syndrome (positive predictive value 0.94, 95%, CI: 0.88 to 0.98). In 3 (6%) patients MR was normal. Aside from old unrelated ischemic (macro- and/or microangiopathic) lesions, MR revealed no acute non-lacunar infarct. CT and MR sites of lacunar lesions were matching. Compared to gold standard MR, the sensitivity of early CT for suspected lacunar lesions was 0.53 (95% CI: 0.38 to 0.67). CONCLUSION: Lacunar syndromes were highly predictive for small deep infarcts on MR. Magnetic resonance brain imaging may be redundant in the setting of a lacunar syndrome supported by a CT that excludes non-ischemic causes of stroke; it may therefore be abandoned in order to reduce costs in the health care system.     

Xenon-enhanced computed tomography cerebral blood flow measurements in acute cerebral ischemia: Review of 56 cases

Objective: Ischemic stroke must be diagnosed promptly if patients are to be treated with thrombolytic therapy. The diagnosis of acute cerebral ischemia, however, is usually based on clinical and computed tomography (CT) scan findings. CT scans are often normal in the first few hours after stroke. The purpose of this study was to determine whether Xenon-enhanced CT (XeCT) cerebral blood flow (CBF) studies could increase the sensitivity of stroke detection in the acute stage. Methods: CBF studies performed within 8 hours of symptom onset were evaluated in 56 patients who presented with hemispheric stroke symptoms. Mean CBF in the symptomatic vascular territory was calculated and compared with the corresponding contralateral area. CBF values below 18 mL/100g/min on 2 adjacent regions of interest were considered ischemic lesions. CT scans and angiograms were compared with the XeCt findings. Neurological condition on admission and discharge was evaluated by using National Institutes of Health Stroke Scale (NIHSS) scores. Results: The mean NIHSS score on admission was 12+/-5. Early CT scans were abnormal in 28 (50%) patients. There were 9 (16%) patients who had normal XeCT scans because of spontaneous reperfusion of the ischemic area. XeCT studies showed an ischemic lesion in 47 (84%) patients. In these patients, the mean CBF in the affected vascular territory was 16+/-8 mL/100g/min compared with 35+/-13 mL/100g/min in the contralateral specular territory (P<0.001). There were no false positive or negative XeCT studies, and the location of the perfusion defect corresponded with the CT and/or angiographic findings in all cases. Eight patients died (14%), and the 48 survivors (86%) had a mean NIHSS score of 9+/-6 on discharge. Conclusions: CBF measurements were correlated with the CT and angiographic results and greatly assisted in the diagnosis of acute ischemic stroke. XeCT studies used for estimating the location and extent of cerebral ischemia may be important in the triage of patients for acute stroke therapy.     

Validation of the Oxfordshire Community Stroke Project syndrome diagnosis derived from a standard symptom list in acute stroke

Background: The Oxfordshire Community Stroke Project (OCSP) classification allows distinction of stroke subtypes with different prognosis. OCSP classification inferred from clinical signs filled out on patient entry forms has been used to facilitate subgroup analysis in clinical trials. However, such procedure has not been validated against clinical diagnosis. In preparation for an acute stroke trial, we set out to perform such a validation. Methods: An OCSP syndrome diagnosis of 194 acute stroke patients in four hospitals was made within 24 h using a standard list with neurological signs, to be filled out by a stroke physician or neurological resident on duty. This was compared with OCSP diagnosis within 2 days of stroke onset by a (blinded) stroke neurologist (‘gold standard’). Results: The proportion of the OCSP syndromes was quite similar between standard list and clinical judgement. Sensitivity, specificity, positive and negative predictive values were respectively: LACS: 0.76, 0.88, 0.72, 0.90; TACS: 0.63, 0.93, 0.62, 0.88; PACS: 0.62, 0.76, 0.63, 0.75; POCS: 0.50, 0.98, 0.60, 0.97. Kappa for agreement was 0.63 (LACS), 0.37 (PACS), 0.50 (TACS). Neuro-imaging falsified stroke subtype diagnosis in 40 cases (20.6%) diagnosed using the standard list, and 42 (21.6%) diagnosed by stroke neurologists. Conclusion: A standard list-derived stroke syndrome diagnosis may be used as a clinical test to make an OCSP syndrome diagnosis in acute stroke. The use of such list in acute stroke trials may facilitate uniformity in early stroke subtype diagnosis. However, to increase such uniformity, ancillary methods such as acute MRI should be evaluated.     

急性脑梗死OCSP分型与吞咽困难的相关性分析

目的研究急性脑梗死OCSP分型与吞咽困难发生的关系。方法收集急性脑梗死患者199例,按牛津郡社区卒中项目（OCSP）分型划分为4型,于入院24h之内行标准床旁吞咽功能评估（SSA）,判断有无吞咽困难,比较其吞咽困难发生率的差异。结果199例患者中吞咽困难者占45．73％（91／199）,TACI（完全前循环梗死）中为76％（19／25）;PACI（部分前循环梗死）中为42．25％（50／113）;POCI（后循环梗死）中为35％（14／40）;LACI（腔隙性梗死）中为38．10％（8／21）。各型患者的吞咽困难发生率的差异存在统计学意义（χ^2=11．679,P〈0．05）,两两比较只有TAcI和其他3型之间差异存在统计学意义（P〈0．05）。结论吞咽困难是脑梗死后的常见症状,OCSP各型吞咽困难发生率的不同与缺血损伤不同区域的吞咽中枢以及缺血的范围和程度有关。     

急性脑梗死症状学、影像学及病因学分类之间的关系研究

目的：探讨急性脑梗死症状学、影像学及病因学分类之间的关系。方法：对125例起病48小时内的急性脑梗死患者进行3步骤分类诊断，第一步为症状学分类：(1)完全前循环梗死(TACI)；(2)部分前循环梗死(PACI)；(3)腔隙性梗死(LACI)；(4)后循环梗死(POCI)。第二步为影像学分类：(1)前循环皮质梗死或纹状体内囊区梗死(C0)；(2)低灌流梗死(LFI)；(3)深穿技区的皮质下小梗死(SSI)；(4)除SSI以外的后循环梗死(PCI)；(5)无异常发现(N0)。第三步为病因学分类：(1)大动脉粥样硬化(LAA)；(2)心源性栓塞(CE)；(3)小动脉病(SAD)；(4)其它病因、病因不明或混合性病因。结果：在症状学分类诊断为TACI、PACI和POCI的患者中，CT或MRI所示病灶与其临床症状的对应性良好，但只有67．3％的LACI影像学分类为SSI。大多数TACI患者是由CE造成的。在PACI患者中，CE和LAA的数量相同。只有57．7％的LACI患者被划分为SAD，而28．8％被划分为LAA。用LACI和SSI来预测SAD的阳性预测率较高(78％)。POCI的病因诊断多种多样。结论：除LACI以外，症状学分类与影像学分类的对应性良好，用症状学分类可预测TACI和PACI患者的病因分类，但难以预测POCI患者的病因分类。不少的LACI是由LAA造成的。     

Relationship between the Oxfordshire Community Stroke Project classification and vascular abnormalities in patients with predominantly intracranial atherosclerosis

BACKGROUND: The Oxfordshire Community Stroke Project (OCSP) classification is a stroke classification based on clinical features collected at bedside. Previous studies reported good correlation between vascular abnormalities and OCSP mainly in populations not at risk of intracranial atherosclerosis. There have been limited data on the relationship between intracranial atherosclerosis and the OCSP classification. METHODS: Consecutive Chinese patients admitted to a regional hospital with acute ischemic stroke were studied in Hong Kong. Stroke subtype was classified as total or partial anterior circulation infarct (TACI or PACI), posterior circulation infarct (POCI), or lacunar infarct (LACI), according to the OCSP method. Transcranial Doppler (TCD) was performed whenever possible to evaluate the intracranial arteries as well as the carotid arteries. National Institute of Health Stroke Scale (NIHSS) was used to assess the severity of stroke on admission. RESULTS: Six hundred and ninety-nine consecutive patients were studied. On admission, 24 patients were classified as TACI (3.4%), 96 PACI (13.7%), 111 POCI (15.9%), and 468 LACI (67.0%). Of the 345 patients who had TCD evidence of intracranial or carotid artery abnormalities, 75% had intracranial involvement only, 5% extracranial involvement only and 20% had both intracranial and extracranial involvement. The frequencies of arterial abnormalities were found in 58% of TACIs, 48% of PACIs, 48% of POCIs and 50% of LACIs. There was no evidence that the frequencies of arterial abnormalities were different between the OCSP groups (P=0.8). Middle cerebral artery velocity was abnormal in 9 TACIs (38%), 32 PACIs (33%), 35 POCIs (32%) and 177 LACIs (38%) (P=0.6). Vertebrobasilar velocities were abnormal in 4 TACIs (17%), 20 PACIs (21%), 29 (26%) and 87 LACIs (19%) (P=0.3). The OCSP subtypes were associated with POCIs the severity of stroke. NIHSS score of > or =9 was found in 83% of TACIs, 18% of PACIs, 9% of POCIs, and 12% of LACIs (P<0.0001). CONCLUSIONS: OCSP classification is not significantly related to the presence of vascular abnormalities among patients with predominantly intracranial atherosclerosis.     

缺血性脑卒中OCSP分型与神经影像学及脑血管改变之间的关系

目的以OCSP分型为基础,结合影像学和DSA表现探讨缺血性卒中OCSP分型、神经影像学改变、血管改变之间的关系。方法回顾性分析227例经DSA证实存在血管狭窄患者的临床资料,据患者主要症状和体征、MRI、CT、DSA的结果进行OCSP分型、影像学分型、及血管病变部位分型。分析OCSP分型与神经影像学及脑血管改变之间的关系。结果 OCSP各型所占的比例依次为:(1)部分前循环梗死型(PACI)占47%;后循环梗死型(POCI)占31%;完全前循环梗死型(TACI)占13%;腔隙性梗死型LACI占9%。(2)OCSP分型中前循环梗死型(TACI+PACI)、腔隙性梗死型(LACI)、后循环梗死型(PCI)与影像学分型中皮质梗死和低灌流区梗死(CO+LFI)、皮质下小梗死(SSI)、后循环病变部位梗死(PCI)的一致率分别为77.97%、79.30%、79.30%。(3)OCSP分型中前循环型(TACI+PACI)和后循环型(POCI)与前循环血管狭窄(ICA+MCA)和后循环血管狭窄(VA+BA)一致率分别为78.41%、71.84%。结论 OCSP分型与神经影像学改变分型和血管改变分型的一致性较好。     

Correlation between symptomatic, radiological and etiological diagnosis in acute ischemic stroke

OBJECTIVES: The aim of this study was to correlate with the symptomatic, radiological and etiological diagnosis in acute ischemic stroke. SUBJECTS AND METHODS: Two hundred and fifty patients with first-ever ischemic stroke within 24 h of onset were prospectively studied with 3-step diagnoses: 1) symptomatic diagnosis based on the Oxfordshire Community Stroke Project criteria (OCSP), 2) radiological diagnosis (CT or MRI) and 3) etiological diagnosis based on the Lausanne Stroke Registry criteria. RESULTS: Most of the patients with symptoms of total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI) and posterior circulation infarcts (POCI) had corresponding lesions on CT or MRI, while only 68% of lacunar infarcts (LACI) patients had small subcortical infarction (SSI). More than 60% of patients with TACI were classified into cardioembolism in the third diagnosis, while the etiology of PACI was either CE or large-artery atherosclerosis (LAA) in equal numbers. Only 58% of LACI patients were classified into small-artery disease (SAD) and 29% of them (30 cases) into LAA, of which 23 patients had lesions other than SSI. The positive predictive value of SAD in the combination of LACI and SSI was 0.78. The etiology of POCI was variable. CONCLUSION: Except for LACI, the symptomatic classification by OCSP corresponds well to the radiological diagnosis. The etiological diagnosis can be predicted by OCSP in TACI and PACI, but it is hard in POCI, and a number of LACI are due to LAA.     

貌似大脑半球病变的脑干梗死临床和影像分析

目的　分析貌似大脑半球病变的脑干梗死的临床和影像学特点及临床定位错误的原因。方法　连续1年观察发病 6h内收治的首发脑梗死 118例 ,先行OCSP(theOxfordshirecommunitystrokeproject)分型、NIHSS评分 (thenationalinstitutesofhealthstrokescale)和超早期头颅CT平扫 ,再结合 72h内的头颅MR筛出貌似大脑半球病变的脑干梗死。结果　 118例中首诊分型 5 0例为腔隙梗死 ,其中 4 4例行MR复查并证实貌似大脑半球病变的脑干梗死 12例。头颅CT均未检出脑干病灶 ,MR准确检出了脑干责任灶。病灶多在脑桥的三叉神经根平面、脑桥旁正中动脉的血供分布区。 11例病灶小于 2 0mm ,呈纵向条状、片状。结论　早期行MR有助于明确诊断貌似大脑半球病变的脑干梗死。对有糖尿病病史、起病有头晕、临床呈单纯运动性轻偏瘫或单纯性偏瘫的LACI,要注意其病灶有可能在脑干。     

缺血性脑卒中的亚型分析

目的探讨我国缺血性脑卒中人群亚型和发病的症状学特征。方法对2002年7月～2003年2月因首发缺血性脑卒中于天坛医院住院治疗的300例患者进行MRI、MRA、DSA等影像学检查及其他病因学检查,依据牛津郡社区卒中计划(OCSP)分型法确定每例患者的所属亚型。结果本组患者OCSP分型各亚型的构成比为:腔隙性脑梗死占21．0%,完全前循环梗死21．0%,部分前循环梗死占36．3%,后循环梗死占21．7%。不同性别患者OCSP分型各亚型的分布间差别无显著性意义(P＞0．05)。结论本研究中部分前循环梗死亚型所占比例最高,不同性别患者各亚型的分布无差别。     

Acute small subcortical infarctions on diffusion weighted MRI: clinical presentation and aetiology

OBJECTIVE: To determine the clinical presentation and aetiology of small subcortical infarctions as found on diffusion weighted magnetic resonance imaging (DWI). DWI is both sensitive and specific in the early detection of acute ischaemic brain lesions irrespective of pre-existing vascular damage. METHODS: Ninety three patients were identified showing subcortical or brainstem DWI lesions <1.5 cm in diameter within a maximum of 7 days from the onset of stroke symptoms. The patients' clinical status on admission was reviewed according to the Oxfordshire Community Stroke Project (OCSP). The results of procedures searching for cerebrovascular risk factors, large artery disease, and potential sources of cardiac embolism were included to determine stroke aetiology. Magnetic resonance imaging scans were also reviewed for concomitant changes that could support the aetiologic classification. RESULTS: Only 41 (44.1%) patients presented clinically with a lacunar syndrome according to OCSP criteria. The nine (9.7%) patients who showed two or more DWI lesions in different vascular territories were also significantly more likely to have potential sources of cardiac embolism (5/9, 55.6% v 20/84, 23.8%). Hypertension was significantly more prevalent in the group of patients who showed a microangiopathy related imaging pattern, but this pattern did not exclude the presence of large artery disease or a possible cardioembolic source of stroke. CONCLUSION: Identification of small subcortical infarctions as the cause of stroke appears quite uncertain based on clinical characteristics only. DWI adds significant aetiologic information but does not obviate the search for other potentially causative mechanisms.     

Stroke severity, early recovery and outcome are each related with clinical classification of stroke: data from the 'Tinzaparin in Acute Ischaemic Stroke Trial' (TAIST)

INTRODUCTION: Baseline severity and clinical stroke syndrome (Oxford Community Stroke Project, OCSP) classification are predictors of outcome in stroke. We used data from the 'Tinzaparin in Acute Ischaemic Stroke Trial' (TAIST) to assess the relationship between stroke severity, early recovery, outcome and OCSP syndrome. METHODS: TAIST was a randomised controlled trial assessing the safety and efficacy of tinzaparin versus aspirin in 1484 patients with acute ischaemic stroke. Severity was measured as the Scandinavian Neurological Stroke Scale (SNSS) at baseline and days 4, 7 and 10, and baseline OCSP clinical classification recorded: total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), lacunar infarct (LACI) and posterior circulation infarction (POCI). Recovery was calculated as change in SNSS from baseline at day 4 and 10. The relationship between stroke syndrome and SNSS at days 4 and 10, and outcome (modified Rankin Scale at 90 days) were assessed. RESULTS: Stroke severity was significantly different between TACI (most severe) and LACI (mildest) at all four time points (p<0.001), with no difference between PACI and POCI. The largest change in SNSS score occurred between baseline and day 4; improvement was least in TACI (median 2 units), compared to other groups (median 3 units) (p<0.001). If SNSS did not improve by day 4, then early recovery and late functional outcome tended to be limited irrespective of clinical syndrome (SNSS, baseline: 31, day 10: 32; mRS, day 90: 4); patients who recovered early tended to continue to improve and had better functional outcome irrespective of syndrome (SNSS, baseline: 35, day 10: 50; mRS, day 90: 2). CONCLUSIONS: Although functional outcome is related to baseline clinical syndrome (best with LACI, worst with TACI), patients who improve early have a more favourable functional outcome, irrespective of their OCSP syndrome. Hence, patients with a TACI syndrome may still achieve a reasonable outcome if early recovery occurs.     

Comparison of diffusion-weighted MRI and CT in acute stroke

OBJECTIVE: To compare diffusion-weighted MRI (DWI) and CT with respect to accuracy of localizing acute cerebral infarction; sensitivity, specificity, and interrater reliability for identifying more than one-third middle cerebral artery (MCA) territory involvement; and correlation of acute lesion volume with final infarct volume. METHOD: Nineteen consecutive stroke patients underwent CT and DWI within 7 hours of stroke onset and a follow-up DWI examination 36 hours after symptom onset, which served as the "gold standard" for lesion location and extent of MCA involvement. Each scan was evaluated for acute ischemic lesions by two experienced observers. After 30 days, T2-weighted MRI was obtained for assessment of the final infarct volume. RESULTS: The acute CT and DWI scans were obtained on average 2.6 and 5.1 hours after symptom onset. On DWI the acute lesion was identified correctly in all instances and on CT it was identified correctly in 42 to 63% of patients. Sensitivity for detection of more than 33% MCA involvement was better for DWI (57 to 86%) than for CT (14 to 43%), whereas specificity was excellent for both. Interrater reliability was moderately good for both (kappa, 0.6 for DWI; 0.5 for CT). A positive correlation (r = 0.79; p = 0.001) existed between lesion volume on acute DWI and final infarct volume, whereas no correlation was found between CT volume and final infarct volume. CONCLUSION: When compared with CT, DWI was more accurate for identifying acute infarction and more sensitive for detection of more than 33% MCA involvement. In addition, lesion volume on acute DWI, but not on acute CT, correlated strongly with final infarct volume. Additional studies are required to demonstrate whether these advantages of DWI are clinically relevant in the management of patients with acute stroke.     

Relationship between subtypes of MRI-confirmed acute ischemic stroke based on OCSP and TOAST classifications

BACKGROUND： Two classification systems exist for subtypes of acute cerebral infarction. One was developed for the Trial of Org 10172 in Acute Stroke Treatment （TOAST）, based primarily on etiology. The other is the Oxfordshire Community Stroke Project （OCSP）, based on clinical features.
OBJECTIVE： To evaluate the relationship between OCSP and TOAST classifications in terms of stroke location and etiology in 126 patients with acute ischemic stroke confirmed by transcranial magnetic resonance imaging （MRI）.
DESIGN, TIME AND SETTING： Retrospective case analysis. Transcranial MRI, diffusion weighted imaging, and magnetic resonance angiography were performed in 126 patients with acute stroke during the first 48 hours following admission to the Department of Neurology, Navy General Hospital of Chinese PLA.
PARTICIPANTS： A total of 126 patients with acute stroke, comprised of 71 males and 55 females, admitted to the Navy General Hospital of Chinese PLA between December 2005 and April 2006 were included.
METHODS： Of 126 patients with acute stroke, 13 exhibited total anterior circulation infarcts （TACI）, 51 had partial anterior circulation infarcts （PACI）, 28 suffered posterior circulation infarcts （POCI）, and 34 had lacunar infarcts （LACI） based on OCSP classification. However, according to TOAST classification, 19 cases were a result of large-artery atherosclerosis, 32 by cardioembolism, 36 by small-vessel occlusion, 1 by stroke of other determined etiology, and 38 by stroke of undetermined etiology.
MAIN OUTCOME MEASURES： The corresponding relationship of the subtypes of acute stroke based on OCSP and TOAST.
RESULTS： Of patients with TACI, 8 （61.5%） were caused by cardioembolism. Of patients with PACI, 16 （31.4%） were caused by large-artery atherosclerosis and 17 （33.3%） by cardioembolism. Of patients with POCI, 12 （42.8%） were a result of small-vessel occlusion. Of patients with LACI, 17 （50.0%） were caused by hypertension and arteriolar sclerosi