Factors related to the initial stroke severity of posterior circulation ischemic stroke.

BACKGROUND: Posterior circulation (PC) stroke, which was previously less well known than anterior circulation (AC) stroke, has become more identified due to the development of imaging equipment. Recently, the initial stroke severity assessed by the NIH Stroke Scale (NIHSS) was reported as a useful measure for predicting the outcome of PC as well as AC stroke. The aim of our study was to investigate the factors related to the stroke severity of PC ischemic stroke as assessed by the baseline NIHSS and the predictors of progressive neurological deficit and 3-month outcome. METHODS: All patients with first-time PC stroke (onset ≤ 7 days), admitted for a 5-year period and given a complete evaluation including brain MRI and angiographic studies, were enrolled. Patients were divided into two groups by the baseline NIHSS: moderate-to-severe stroke (MTSS, NIHSS > 5) and mild stroke (MS, NIHSS ≤ 5). Baseline characteristics, symptoms and progression, etiological subtypes, lesion characteristics from imaging, and patient 3-month outcome assessed by the modified Rankin Scale (mRS) were compared between the two groups. RESULTS: Among 604 enrolled patients with PC ischemic stroke, 143 belonged to the MTSS group and 461 to the MS group. In logistic regression analysis, MTSS was independently associated with white blood cell count (odds ratio, OR = 1.00, p = 0.001), high sensitivity C-reactive protein level (OR = 1.23, p = 0.004), dysarthria (OR = 2.59, p = 0.013), weakness (OR = 6.43, p < 0.001), dysphagia (OR = 5.77, p < 0.001) and decreased consciousness (OR = 10.54, p < 0.001). The independent predictors associated with progressive neurological deficit were MTSS (OR = 3.82, p = 0.001), the distal territory classified by lesion location (OR = 0.09, p = 0.004) and dysphagia (OR = 2.38, p = 0.010). The independent predictors associated with a 3-month mRS of 3-6 were MTSS (OR = 7.69, p < 0.001), diplopia (OR = 0.26, p = 0.023), visual field defect (OR = 4.87, p = 0.014), dysphagia (OR = 3.15, p < 0.001) and progressive neurological deficit (OR = 4.27, p < 0.001). CONCLUSIONS: The initial severity categorization of PC ischemic stroke by the NIHSS has provided several distinctions and could help with the prediction of neurological deficit progression and 3-month clinical outcome.

Long-term outcome in posterior cerebral artery stroke.

INTRODUCTION: Previous studies on posterior cerebral artery (PCA) strokes focused mainly on topography and underlying pathophysiology. However, there are no data on long-term prognosis and its association with the localization of the infarct. METHODS: All consecutive PCA strokes registered in the Athens Stroke Outcome Project between 01/1998 and 12/2009 were included in the analysis. The New England Posterior Circulation Registry criteria were applied to classify them in relation to topography: (i) pure PCA infarcts, including pure cortical-only and combined cortical/deep PCA infarcts (groups A and B respectively), and (ii) PCA-plus strokes, including cortical-only and combined cortical/deep PCA strokes with ≥1 concomitant infarcts outside PCA territory (groups C and D respectively). Patients were prospectively followed up to 10 years after stroke. RESULTS: Amongst 185 (8.1%) PCA patients that were followed up for 49.6±26.7months, 98 (53%), 24 (13%), 36 (19.5%), and 27 (14.6%) were classified in group A, B, C, and D, respectively. Infections and brain edema with mass effect were more frequently encountered in PCA-plus strokes compared to pure PCA (P<0.05 and <0.01 respectively). At 6 months, 56% of cortical-only PCA patients had no or minor disability, compared to 37%, 36%, and 26% in the other groups (P=0.015). The 10-year probability of death was 55.1% (95%CI: 42.2-68.0) for pure PCA compared to 72.5% (95%CI: 58.8-86.2) for PCA-plus (log-rank 14.2, P=0.001). Long-term mortality was associated with initial neurologic severity and underlying stroke mechanism. CONCLUSIONS: Patients with pure PCA stroke have significantly lower risk of disability and long-term mortality compared to PCA strokes with coincident infarction outside the PCA territory.

[Topography of ischemic strokes in Abidjan (Côte d'Ivoire): a computed tomographic approach]. / Approche tomodensitométrique des accidents vasculaires cérébraux ischémiques à Abidjan (Côte d'Ivoire).

OBJECTIVE: The authors used computed tomography (CT) to assess and categorize the topography of ischemic strokes (IS) among blacks living in Abidjan, the commercial and administrative center of Côte d'Ivoire, in West Africa. METHODS: This retrospective study analyzed CT data of patients admitted to the Sainte Anne Marie Polyclinic (the principal private hospital in the country) and to the neurology department of the university hospital center in Cocody, from January 1, 2000, to December 31, 2001. The study included patients who met World Health Organisation criteria for stroke and had CT performed during the hospitalization for this stroke. We examined CT data to find early and late signs of IS, analyze lesion diameter (15 mm cutoff used to distinguish infarcts from lacuna), and determine their topography (cerebral arterial territory and localization, that is, brain lobes, basal ganglia and posterior cerebral fossa). RESULTS: We included 260 subjects (58% males) with a median age of 45 years (range: 20-80 years). CT findings were abnormal for 224 patients with infarcts (72.7%), lacuna (27.3%), or both (8%). As reported elsewhere, the anterior arterial territory was most often affected (83.9%) with a middle cerebral artery lesion in 79.4% of patients. Posterior territory (16.1%) lesions and lacuna were probably underestimated because CT exploration is reported to be less useful for this area than for the carotid area. On the other hand, CT diagnoses infarcts more easily than it does lacuna. CT was normal for 36 patients although performed no more than 3 days after IS. These patients did not undergo CT angiography, which might have shown cerebral artery occlusion. CONCLUSION: Our study included IS of all types and typography. Stroke registries in Africa would provide useful data for better assessment of prevalence for specific topographic and etiologic types of stroke.

Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification and vascular territory of ischemic stroke lesions diagnosed by diffusion-weighted imaging.

BACKGROUND: The association between the location and the mechanism of a stroke lesion remains unclear. A diffusion-weighted imaging study may help resolve this lack of clarity. METHODS AND RESULTS: We studied a consecutive series of 2702 acute ischemic stroke patients whose stroke lesions were confirmed by diffusion-weighted imaging and who underwent a thorough etiological investigation. The vascular territory in which an ischemic lesion was situated was identified using standard anatomic maps of the dominant arterial territories. Stroke subtype was based on the Trial of ORG 10172 in Acute Stroke Treatment, or TOAST, classification. Large-artery atherosclerosis (37.3%) was the most common stroke subtype, and middle cerebral artery (49.6%) was the most frequently involved territory. Large-artery atherosclerosis was the most common subtype for anterior cerebral, middle cerebral, vertebral, and anterior and posterior inferior cerebellar artery territory infarctions. Small vessel occlusion was the leading subtype in basilar and posterior cerebral artery territories. Cardioembolism was the leading cause in superior cerebellar artery territory. Compared with carotid territory stroke, vertebrobasilar territory stroke was more likely to be caused by small vessel occlusion (21.4% versus 30.1%, P<0.001) and less likely to be caused by cardioembolism (23.2% versus 13.8%, P<0.001). Multiple-vascular-territory infarction was frequently caused by cardioembolism (44.2%) in carotid territory and by large-artery atherosclerosis (52.1%) in vertebrobasilar territory. CONCLUSIONS: Information on vascular territory of a stroke lesion may be helpful in timely investigation and accurate diagnosis of stroke etiology.

Oxfordshire Community Stroke Project classification but not NIHSS predicts symptomatic intracerebral hemorrhage following thrombolysis.

BACKGROUND: The Oxfordshire Community Stroke Project (OCSP) classification is a simple tool to categorize clinical stroke syndromes. We compared the outcomes of stroke patients after intravenous thrombolysis stratified by the baseline National Institutes of Health Stroke Scale (NIHSS) score or by the OCSP classification. METHODS: We assessed the safety of thrombolysis in consecutive stroke patients who received intravenous thrombolysis within 3h after onset. The patients were grouped by the NIHSS score into mild to moderate stroke (≤ 20) and severe stroke (>20), and also by the OCSP classification as having total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), posterior circulation infarcts (POCI), or lacunar infarcts (LACI). Symptomatic intracerebral hemorrhage (SICH) was used as the primary outcome. RESULTS: Of the 145 patients included in the study, 45 had a baseline NIHSS score>20. Their stroke syndromes were as follows: 78 with TACI, 29 with PACI, 16 with POCI, and 22 with LACI. The proportion of SICH was comparable between patients with high or low NIHSS score (11.1% vs. 9.0%, P=0.690). The chance of SICH was highest in patients with TACI (15.4%), followed by LACI (4.5%), PACI (3.4%), and POCI (0%). After adjustment for age, baseline glucose, and use of antiplatelet agents before admission, SICH was significantly increased in patients with TACI relative to those with non-TACI (odds ratio 5.92; 95% confidence interval 1.24-28.33, P=0.026). CONCLUSIONS: The OCSP clinical classification may help clinicians evaluate the risk of SICH following intravenous thrombolysis.

Stroke of the posterior cerebral circulation.

AIM: Identification of stroke etiology aids in developing secondary prevention and treatment strategies for posterior circulation stroke (PCS). Studies have identified large vessel atherosclerotic disease as the predominant etiology and others have cited cardioembolism. This study was designed to describe the prevalence, outcome, and stroke mechanisms of PCS and to analyze the strengths and weaknesses of the classifications used. METHODS: A comprehensive MEDLINE search identified seven studies evaluating the etiology of PCS. Incoherent data and lack of prospective studies made performance of a thorough meta-analysis impossible. Special attention was paid to the design of trials and the classifications used. In a similar way, the limitations of each study were clearly determined. RESULTS: Seven trials encompassing 8057 patients, of which 23% were isolated PCS and 4% were combined ACS and PCS, were analyzed. Overall, large vessel atherosclerotic disease was responsible for 35% of PCS, cardioembolism for 18%, small vessel disease for 13% and undetermined etiology for 15%. Strokes of mixed and "other" etiology represented 4% and 8% of PCS respectively. Major sequelae were observed in 10.8-17.7% of patients with no sequelae noted in 7-28% of patients. Mortality ranged from 4-10% and it was directly related to stroke in 2-5%. CONCLUSION: Large vessel atherosclerotic disease was the most common stroke subtype identified. Conclusions are inconsistent between the studies, highlighting the difficulties in systematic investigations of stroke etiology and the need for a unified approach to stroke classification.

Spectrum of superficial posterior cerebral artery territory infarcts.

Posterior cerebral artery (PCA) territory infarction is not uncommon. Published series were concentrated either on isolated deep PCA territory infarcts or on incomplete calcarine artery territory infarcts. Although, correlations between clinical symptoms, causes of stroke and outcome at 6-months in patients with superficial PCA territory stroke are less well known. We sought prospectively stroke causes, infarct topography, and clinical findings of 137 patients with superficial PCA territory infarcts with or without mesencephalic/thalamic involvement, representing 11% of patients with posterior circulation ischemic stroke in our Stroke Registry. We analyzed patients by subdividing into three subgroups; (1). cortical infarct (CI) group; (2). cortical and deep infarcts (CDI) (thalamic and/or mesencephalic involvement) group; (3). bilateral infarcts (BI) group. We studied the outcomes of patients at 6-month regarding clinical findings, risk factors and vascular mechanisms by means of comprehensive vascular and cardiac studies. Seventy-one patients (52%) had cortical (CI) PCA infarct, 52 patients (38%) had CDI, and 14 patients (10%) had bilateral PCA infarct (BI). In the CDI group, unilateral thalamus was involved in 38 patients (73%) and unilateral mesencephalic involvement was present in 27% of patients. The presumed causes of infarction were intrinsic PCA disease in 33 patients (26%), proximal large-artery disease (PLAD) in 33 (24%), cardioembolism in 23 (17%), co-existence of PLAD and cardioembolism in 7 (5%), vertebral or basilar artery dissection in 8 (6%), and coagulopathy in 2. The death rate was 7% in our series and stroke recurrence was 16% during 6-month follow-up period. Features of the stroke that was associated with significant increased risk of poor outcome included, consciousness disturbances at stroke onset (RR, 66.6; 95% CI, 8.6-515.5), mesencephalic and/or thalamic involvement (RR, 3.79; 95% CI, 1.49-9.65), PLAD (RR, 2.71; 95% CI, 1.09-6.73), and basilar artery disease (RR, 5.94; 95% CI, 1.73-20.47). The infarct mechanisms in three different types of superficial PCA territory stroke were quite similar, but cardioembolism was found more frequent in those with cortical PCA territory infarction. Although, the cause of stroke could not reliably dictate the infarct topography and clinical features. Visual field defect was the main clinical symptom in all groups, but sensorial, motor and neuropsychological deficits occurred mostly in those with CDI. Outcome is good in general, although patients having PLAD and basilar artery disease had more risk of stroke recurrence and poor outcome rather than those with intrinsic PCA disease.