Intracranial vascular calcification is protective from vasospasm after aneurysmal subarachnoid hemorrhage.

Vasospasm after aneurysmal subarachnoid hemorrhage was noted in some studies to be less frequent and less severe in older age. One hypothesis is that atherosclerosis makes arteries too stiff to spasm. The objective of this study was to assess the association between intracranial calcification, a marker for atherosclerosis, and vasospasm. Charts and nonenhanced computed tomography scans of patients with subarachnoid hemorrhage were retrospectively reviewed. Transcranial Doppler studies were used to categorize vasospasm using mean flow velocity: mild vasospasm 120-199 cm/second and severe ≥ 200 cm/second. Calcification of the intracranial internal carotid artery was quantified by calculating the volume and density of the calcified lesions. A total of 172 patients met study criteria (mean age, 54 ± 13 years; 88 women). Patients who had calcification (n = 90; 52%) were significantly older (61 ± 12 years vs. 46 ± 10 years; P < .0001). Mean calcification score was 532 ± 853. Calcification score was directly associated with age (P < .0001) and inversely associated with mean flow velocity (P = .0027). Only the highest tertile was independently associated with less vasospasm (odds ratio, .34; 95% confidence interval, .12-.93). There was an interaction between calcification score and age in which age greater than 65 years was only protective of vasospasm when combined with the highest calcification tertile. We conclude that intracranial calcification is associated with lower rates of vasospasm. The amount of visualized calcification inversely influences the severity of vasospasm. Calcification, and the underlying presumed atherosclerosis, maybe 1 mechanism by which vasospasm has lower frequency and severity in older age.

Comparison of acute nonthrombolytic and thrombolytic treatments in ischemic stroke patients 80 years or older.

OBJECTIVES: The aim of this study was to compare the clinical outcomes of acute ischemic stroke patients 80 years or older treated with intravenous recombinant tissue plasminogen activator (i.v. rt-PA), or endovascular intervention with or without i.v. rt-PA, or nonthrombolytic medical treatment. METHODS: This study was a retrospective, nonrandomized, observational study of patients, admitted within 9 hours of symptom onset, at 3 academic, university-affiliated hospitals. The main outcome measures were neurologic improvement, defined by improvement in National Institutes of Health Stroke Scale score at 7 days or discharge of 4 or more, or achieving a score of 0; symptomatic and asymptomatic intracerebral hemorrhage; favorable outcome (discharge modified Rankin score 0-2); and in-hospital mortality. RESULTS: A total of 44 patients received i.v. rt-PA, 46 received endovascular intervention with or without i.v. rt-PA, and 66 received nonthrombolytic medical treatment. I.v. rt-PA-treated patients had a significantly clinically higher chance of favorable outcome (odds ratio [OR], 5.6; 95% confidence interval [CI], 1.8-17.5), when compared with nonthrombolytic medical treatment. A significantly higher rate of neurologic improvement was observed among the i.v. rt-PA (7.2; 95% CI, 2.7-19.5) and endovascularly treated patients (5.8; 95% CI, 2-16.8) when compared with nonthrombolytic medical treatment. CONCLUSIONS: A prominently higher rate of neurologic improvement and favorable clinical outcome was observed among acute ischemic stroke patients 80 years or older treated with i.v. rt-PA or endovascular intervention when compared with nonthrombolytic medical treatment, supporting the use of acute thrombolytic therapies in this patient population when contraindications are not present.

Agreement in endovascular thrombolysis patient selection based on interpretation of presenting CT and CT-P changes in ischemic stroke patients.

BACKGROUND: To evaluate the agreement in patient selection based on computed tomography (CT) and CT-perfusion (CT-P) imaging interpretation between stroke specialists in stroke patients considered for endovascular treatment. METHODS: All endovascular-treated acute ischemic stroke patients were identified through a prospective database from two comprehensive stroke centers; 25 consecutively treated patients were used for this analysis. Initial CT images and CT-P data were independently interpreted by five board eligible/certified vascular neurologists with additional endovascular training to decide whether or not to select the patient for endovascular treatment. The CT/CT-P images were evaluated separately and used as the sole imaging decision making criteria, 2 weeks apart from each other (memory wash-out period). For each set of imaging data inter-rater and intra-rater agreement scores were obtained using Cohen's kappa statistic to assess the proportion of agreement beyond chance. RESULTS: Kappa values for the treatment decisions based on CT images was 0.43 (range 0.14-0.8) (moderate agreement), and for the decisions based on CTP images was 0.29 (range 0.07-0.67) (fair agreement) among the five subjects. There was substantial variability within the group and between images interpretation. Observed agreement on decision to treat with endovascular therapy was found to be 75% with CT images and 59% with CT-P images (with no adjustment for chance). Kappa values for intra-rater agreement were -0.14 (ranged -0.27-0.27) (poor agreement). CONCLUSIONS: There is considerable lack of agreement, even among stroke specialists, in selecting acute ischemic stroke patients for endovascular treatment based on CT-P changes. This mandates a careful evaluation of CT-P for patient selection before widespread adoption.

Outcomes after nontraumatic subarachnoid hemorrhage at hospitals offering angioplasty for cerebral vasospasm: a national level analysis in the United States.

BACKGROUND: Primary angioplasty has been introduced for the treatment of symptomatic cerebral vasospasm in patients with subarachnoid hemorrhage (SAH). The data regarding the therapeutic benefit of angioplasty in improving patient outcomes are limited, hence its utilization at hospitals remains controversial and currently is not reimbursed by Medicare or major insurance companies. METHODS: We analyzed the data from Nationwide Inpatient Sample (NIS), a nationally representative dataset of all admissions in the United States from 2005 to 2007. We analyzed the prevalence of angioplasty procedure for cerebral vasospasm at the national level. In-hospital mortality, discharge status, length of stay, and cost of hospitalization were compared between hospitals performing angioplasty with those not performing angioplasty in multivariable model, adjusted for patient's age, utilization of endovascular aneurysm obliteration, and disease severity. RESULTS: Of the 74,356 estimated patients with nontraumatic SAH, 47% (n = 35,172) were admitted to hospitals that perform angioplasty for cerebral vasospasm and only 1307 patients (3.8%) were treated with angioplasty for vasospasm. In multivariable analysis, after adjustment for patient and hospital characteristics, we found that patients admitted to hospitals performing angioplasty had higher rates of discharge to home without supervision (OR 1.3, 95% CI: 1.1-1.6). There was no difference in in-hospital mortality, length of stay, or cost of hospitalization. CONCLUSIONS: Our analysis suggests that the odds of a patient being discharged to home are better at hospitals performing angioplasty for cerebral vasospasm. Provision of angioplasty may be used as a surrogate marker of model of care in management of patients with SAH.

Impact of percutaneous transluminal angioplasty for treatment of cerebral vasospasm on subarachnoid hemorrhage patient outcomes.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) has been introduced for treatment of symptomatic cerebral vasospasm in patients with subarachnoid hemorrhage (SAH). While angiographic improvement is consistently reported, clinical improvement following the procedure varies, and limited data is available regarding overall impact on outcome. METHODS: The authors performed a retrospective analysis of all hospital admissions with aneurysmal SAH over a 6 year period. The length of stay, discharge outcomes (measured by modified Rankin scale [mRS] at discharge), and 1-year mortality among patients with SAH before (4 year period) and after (2 year period) institution of PTA for cerebral vasospasm were compared. Embolization for intracranial aneurysm was used as a therapeutic option throughout the study duration. The effect of institution of PTA for vasospasm after adjusting for age, clinical severity, and use of aneurysm embolization on both discharge outcomes and 1-year mortality in multivariate analysis was evaluated. RESULTS: A total of 146 patients with aneurysmal SAH were admitted during the study duration. There was no difference between the 89 patients admitted in pre-angioplasty period and 57 patients admitted in post-angioplasty period in regards to age, medical co-morbidities, and admission clinical severity of patients (measured by Hunt and Hess grade and Glasgow coma scale). A total of 18 (32%) patients underwent PTA with or without intra-arterial vasodilator treatment in the second period of the study. There was a non significant decrease in rates of severe disability and death (mRS 5-6) at discharge (45 vs. 33%, P = 0.09) and 1-year mortality (32 vs. 22%, P = 0.26) after introduction of PTA for cerebral vasospasm after adjusting for potential confounders. There was no significant difference between the two time periods in regards to length of stay. CONCLUSION: A non significant trend was noted with reduced rate of severe disability and mortality at discharge and 1-year mortality after the introduction of PTA for cerebral vasospasm associated with SAH without increasing the length of hospital stay.

Association of serum glucose concentrations during acute hospitalization with hematoma expansion, perihematomal edema, and three month outcome among patients with intracerebral hemorrhage.

BACKGROUND: There is some evidence that hyperglycemia increases the rate of poor outcomes in patients with intracerebral hemorrhage (ICH). We explored the relationship between various parameters of serum glucose concentrations measured during acute hospitalization and hematoma expansion, perihematomal edema, and three month outcome among subjects with ICH. METHODS: A post-hoc analysis of a multicenter prospective study recruiting subjects with ICH and elevated systolic blood pressure (SBP) ≥170 mmHg who presented within 6 h of symptom onset was performed. The serum glucose concentration was measured repeatedly up to 5 times over 3 days after admission and change over time was characterized using a summary statistic by fitting the linear regression model for each subject. The admission glucose, glucose change between admission and 24 hour glucose concentration, and estimated parameters (slope and intercept) were entered in the logistic regression model separately to predict the functional outcome as measured by modified Rankin scale (mRS) at 90 days (0-3 vs. 4-6); hematoma expansion at 24 h (≤33 vs. >33%); and relative perihematomal edema expansion at 24 h (≤40 vs. >40%). RESULTS: A total of 60 subjects were recruited (aged 62.0 ±15.1 years; 56.7% men). The mean of initial glucose concentration (±standard deviation) was 136.7 mg/dl (±58.1). Thirty-five out of 60 (58%) subjects had a declining glucose over time (negative slope). The risk of poor outcome (mRS 4-6) in those with increasing serum glucose levels was over two-fold relative to those who had declining serum glucose levels (RR = 2.64, 95% confidence interval [CI]: 1.03, 6.75). The RRs were 2.59 (95% CI: 1.27, 5.30) for hematoma expansion >33%; and 1.25 (95% CI: 0.73, 2.13) for relative edema expansion >40%. CONCLUSIONS: Decline in serum glucose concentration correlated with reduction in proportion of subjects with hematoma expansion and poor clinical outcome. These results provide a justification for a randomized controlled clinical trial to evaluate the efficacy of aggressive serum glucose reduction in reducing death and disability among patients with ICH.

Indications and applications for extracranial carotid artery stent placement.

Treatment of high-grade symptomatic carotid stenosis via carotid endarterectomy has been shown to be superior to medical management alone in several studies. Carotid angioplasty and stenting (CAS) has emerged as an alternative approach to endarterectomy to reduce the associated perioperative risks. Several anatomic and physiologic factors that increase the risk of stroke and/or death associated with endarterectomy have been identified. The alternative approach of CAS has been found to be noninferior to endarterectomy for high surgical risk patients with severe symptomatic carotid stenosis and the use of this procedure is supported by the current widely accepted guidelines. In patients with standard surgical risk, the differential benefit of CAS compared with endarterectomy is not clear. Several advantages of CAS have been identified in previous studies in selected patients. The results of CAS will undoubtedly continue to improve with advances in device designs, technological expertise, and appropriate patient selection.

Prehospital neurologic deterioration in patients with intracerebral hemorrhage.

OBJECTIVE: Early neurologic deterioration has been studied in patients with intracerebral hemorrhage during hospitalization, but rates and factors associated with prehospital neurologic deterioration (PND) are unknown. We sought to determine the prevalence of PND among patients with intracerebral hemorrhage during Emergency Medical Services transportation to the hospital. DESIGN: Historical cohort study. SETTINGS: U.S. acute care hospital from 2000 to 2004. PATIENTS: Hospitalized patients with a diagnosis of spontaneous intracerebral hemorrhage were identified by codes of the International Statistical Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). METHODS: The initial Glasgow Coma Scale score ascertained at the scene by the Emergency Medical Services was compared with the subsequent evaluation in the emergency department to identify neurologic deterioration (defined as a decrease in Glasgow Coma Scale of > or = 2 points). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 98 patients with acute intracerebral hemorrhage, 22 patients (22%) showed PND during Emergency Medical Services transport, with a mean decrease in the Glasgow Coma Scale score during transport of 6 points. The patients who demonstrated neurologic deterioration tended to have higher diastolic blood pressure at the scene (p = .045), greater rates of intraventricular extension (p < .0001), and radiologic signs of herniation (p < .0001) on initial computed tomographic scan. There was a statistically significant decrease in diastolic blood pressure between the evaluations of the Emergency Medical Services and the emergency department among both patients with and without PND. CONCLUSIONS: PND occurs in nearly one fifth of patients with intracerebral hemorrhage. Higher diastolic blood pressure at the scene, intraventricular extension, and radiologically evident herniation seem to be associated with PND. Prospective studies are needed to evaluate the efficacy of Emergency Medical Services interventions to reduce this early clinical deterioration.

Neuroimaging in stroke and seizure as neurological emergencies (NISSAN) study.

OBJECTIVE: To report the current national utilization of neuroimaging in the emergency department for the two most common neurological emergencies; stroke and seizure. METHODS: Patients were identified using primary International Classification of Diseases (ICD)-9-CM codes from the 2004 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is designed to collect data on the utilization and provision of care in emergency departments of hospitals in the United States. We analyzed the use of neuroimaging in patients presenting to the emergency department with seizure or stroke. RESULTS: About 60% of 1,190,219 patients with the diagnosis of stroke or seizure had neuroimaging performed emergently. Patients with any type of stroke were more likely to undergo neuroimaging compared to patients with seizure (78% vs. 37%, P < .05). When stroke subtypes were analyzed separately, neuroimaging was performed in the emergency department among 100% of patients with subarachnoid hemorrhage, 79% with ischemic stroke, and 69% with intracerebral hemorrhage. CONCLUSIONS: In a nationally representative study, emergent neuroimaging appeared to be underutilized among patients with ischemic stroke and intracerebral hemorrhage. There is a need to increase the utilization of neuroimaging in the emergency department in anticipation of new acute stroke treatments.

Postprocedure intravenous eptifibatide following intra-arterial reteplase in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Early use of intravenous platelet glycoprotein IIB/IIIA antagonists after intra-arterial (IA) thrombolysis may reduce the risk of reocclusion and microvascular compromise. METHODS: We performed a retrospective study to determine the in-hospital outcomes using serial neurological evaluations and imaging among patients treated with intravenous eptifibatide administered as a 135 microg/kg single-dose bolus, followed by 0.5 microg/kg/min infusions for 20 to 24 hours following treatment with IA reteplase. RESULTS: Twenty patients were treated (mean age +/- standard deviation, 68.4 +/- 14.5 years; median National Institutes of Health Stroke Scale [NIHSS] score was 17). The dose of reteplase ranged from 0.5 to 4 units. Eleven patients demonstrated early neurological improvement, defined as a decline of > or =4 points on the 24 hours NIHSS score compared with initial NIHSS score; neurological deterioration, defined as an increase of > or =4 points on the 24 hours NIHSS score as compared with initial NIHSS score, was observed in one patient. Two asymptomatic intracerebral hemorrhages were observed while no symptomatic hemorrhages were observed on serial computed tomographic scans. CONCLUSIONS: The use of intravenous eptifibatide within 24 hours in selected patients after IA thrombolysis is feasible and safe. Further studies are required to determine the benefit of early use of intravenous eptifibatide following thrombolysis.

Validation of two different grading schemes to identify patients with asymptomatic carotid artery stenosis in general population.

BACKGROUND: Identification of significant asymptomatic carotid artery stenosis (ACAS) is important because of potential stroke-risk reduction offered by carotid endarterectomy. We present an external validation of two previously developed scoring schemes designed to identify patients with ACAS. METHODS: We used the data from the Cardiovascular Health Study (CHS)-a cohort study of cardiovascular risk factors, for external validation. Carotid Doppler ultrasound was performed in study participants. Two grading schemes, which used age more than 65 years, current smoking, and history of coronary artery disease and hyperlipidemia as predictors for ACAS, were validated using this dataset. RESULTS: A total of 5,449 persons (mean age 72 +/- 5 years; 42% men; and 84% white) were screened. The overall prevalence of ACAS of > or =50% was 4.2%. The prevalence of ACAS in the highest risk category was 19% in both stratification schemes. The stratification remained effective in the white sub-population (P < .001), but was not significant in the African American population (P > .05). CONCLUSION: Both schemes were effective in identifying persons with ACAS among general population aged 65 years or greater. A subset with a prevalence of ACAS of greater than 20% can be identified using these schemes making screening cost-effective among white population.

Changes in cost and outcome among US patients with stroke hospitalized in 1990 to 1991 and those hospitalized in 2000 to 2001.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the impact of new treatments by examining the changes between 1990 to 1991 and 2000 to 2001 in in-hospital mortality rates and hospital charges in adult patients with stroke. METHODS: From the Nationwide Inpatient Survey, the largest all-payer inpatient care database in the United States, patients with stroke admitted in 1990 to 1991 or 2000 to 2001 were studied. We analyzed hospital charges (adjusted for inflation based on the Consumer Price Index of the Bureau of Labor Statistics) and patient outcomes by type of institution: rural, urban nonteaching, and urban teaching in 1990 to 1991 and in 2000 to 2001. RESULTS: In 1990 to 1991, there were 1 736 352 admissions for cerebrovascular diseases, and in 2000 to 2001, there were 1 958 018 admissions. The number of admissions in urban teaching hospitals increased by 13%, 19%, and 25%, for ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage, respectively. The overall in-hospital mortality rate relatively declined by 36% for ischemic stroke, by 6% for intracerebral hemorrhages, and by 10% for subarachnoid hemorrhage. The mean hospital charges increased from $10 500 to $16 200 for patients with ischemic stroke, from $18 300 to $28 800 for patients with intracerebral hemorrhage, and from $37 400 to $65 900 for patients with subarachnoid hemorrhage. Mortality rates among patients admitted after ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage were all lower in urban teaching hospitals than in rural and urban nonteaching hospitals and the mean charges per admission were all higher. CONCLUSIONS: There has been an increase in the inflation-adjusted hospital charges for all patients with stroke and a reduction in mortality rates for all stroke subtypes probably related to an increase in the proportion of patients with stroke admitted to urban teaching hospitals.

Acute hypertension in intracerebral hemorrhage: pathophysiology and treatment.

Non-traumatic or spontaneous intracerebral hemorrhage (ICH) is defined as intra-parenchymal bleeding with or without extension into the ventricles and rarely into the subarachoid space. Primary ICH in most cases is associated with chronic hypertension. Acute hypertension is associated with hematoma expansion, and poor neurological outcome. The treatment of hypertension in acute ICH is a topic of controversy. Experiments have shown an area of ischemia around the hematoma, with the reduction of regional cerebral blood flow (CBF) secondary to compression of microvasculature. Not all scientific results agree with the above findings. Recent studies have shown that CBF decreases in the perihematoma region but with concomitant reduction of cerebral metabolism, which would argue against an area of ischemia in the perihematoma region. Based on the above result, there have been several clinical trials looking at clinical outcome and decrease in hematoma expansion rates with reduction of blood pressure acutely after ICH. The parameters for the blood pressure control are still under investigation. The American Heart Association has put forward guidelines for blood pressure control which have been adopted in the centers around the country. We have described the protocol we use at our center for the blood pressure control in patients with acute ICH.

Primary percutaneous transluminal angioplasty for early moyamoya disease.

Moyamoya disease is a progressive steno-oclusive arteriopathy of the circle of Willis that manifests on cerebral angiography with a characteristic net of vessels at the base of the brain representing collateralization. Described initially in Japan where children present with cerebral ischemia and adults with hemorrhagic stroke, it was recognized to have a more benign course in the United States, mainly causing cerebral ischemic events in young adults. Medical treatment is not intended to stop the progression of the disease and surgery is not exempt of risks. We present a patient with early moyamoya disease in the United States in whom primary transluminal angioplasty, a less invasive procedure, was performed to treat the stenotic arteriopathy with good immediate and sustained clinical and angiographic results, without evidence of restenosis at the site of angioplasty 2 years later.

CT angiography with whole brain perfused blood volume imaging: added clinical value in the assessment of acute stroke.

BACKGROUND AND PURPOSE: In CT angiographic and perfusion imaging (CTA/CTP), rapid CT scanning is performed during the brief steady state administration of a contrast bolus, creating both vascular phase images of the major intracranial vessels and perfused blood volume-weighted parenchymal phase images of the entire brain. We assessed the added clinical value of the data provided by CTA/CTP over that of clinical examination and noncontrast CT (NCCT) alone. METHODS: NCCT and CTA/CTP imaging was performed in 40 patients presenting with an acute stroke. Short clinical vignettes were retrospectively prepared. After concurrent review of the vignettes and NCCT, a stroke neurologist rated infarct location, vascular territory, vessel(s) occluded, and Trial of Org 10172 in Acute Stroke Treatment (TOAST) and Oxfordshire Community Stroke Project classifications. The ratings were repeated after serial review of each of the CTA/CTP components: (1) axial CTA source images; (2) CTP whole brain blood volume-weighted source images; and (3) maximum-intensity projection 3-dimensional reformatted images. The sequential ratings for each case were compared with the final discharge assessment. RESULTS: Compared with the initial review after NCCT, CTA/CTP improved the overall accuracy of infarct localization (P<0.001), vascular territory determination (P=0.003), vessel occlusion identification (P<0.001), TOAST classification (P=0.039), and Oxfordshire Community Stroke Project classification (P<0.001) by 40%, 28%, 38%, 18%, and 32%, respectively. CONCLUSIONS: Admission CTA/CTP imaging significantly improves accuracy, over that of initial clinical assessment and NCCT imaging alone, in the determination of infarct localization, site of vascular occlusion, and Oxfordshire classification in acute stroke patients.

Association of ischemic lesion patterns on early diffusion-weighted imaging with TOAST stroke subtypes.

BACKGROUND: Different topographic patterns in patients who experience an acute ischemic stroke may be related to specific stroke causes. OBJECTIVE: To determine if lesion patterns on early diffusion-weighted imaging (DWI) are associated with stroke subtypes determined by the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification. DESIGN: Cross-sectional study. SETTING: General community hospital. Patients We studied 172 consecutive ischemic stroke patients with a symptomatic lesion on DWI performed within 24 hours of stroke onset. MAIN OUTCOME MEASURES: Lesion patterns on DWI were classified into single lesions (corticosubcortical, cortical, subcortical > or =15 mm, or subcortical <15 mm), scattered lesions in one vascular territory (small scattered lesions or confluent with additional lesions), and multiple lesions in multiple vascular territories (in the unilateral anterior circulation, in the posterior circulation, in bilateral anterior circulations, or in anterior and posterior circulations). RESULTS: We found an overall significant relationship between DWI lesion patterns and TOAST stroke subtypes (P<.001). Corticosubcortical single lesions (P =.01), multiple lesions in anterior and posterior circulations (P =.03), and multiple lesions in multiple cerebral circulations (P =.008) were associated with cardioembolism. Multiple lesions in the unilateral anterior circulation (P =.04) and small scattered lesions in one vascular territory (P =.06) were related to large-artery atherosclerosis. Nearly half (11/23) of the patients with a single subcortical lesion that was 15 mm or larger were classified as having cryptogenic strokes (P =.001), although 9 of these patients had a classic lacunar syndrome without cortical hypoperfusion. CONCLUSIONS: Early DWI lesion patterns are associated with specific stroke causes. Conventional 15-mm criteria for lacunes, however, may underestimate the diagnosis of small-vessel occlusion with DWI.

Comparison of MRI and CT for detection of acute intracerebral hemorrhage.

CONTEXT: Noncontrast computed tomography (CT) is the standard brain imaging study for the initial evaluation of patients with acute stroke symptoms. Multimodal magnetic resonance imaging (MRI) has been proposed as an alternative to CT in the emergency stroke setting. However, the accuracy of MRI relative to CT for the detection of hyperacute intracerebral hemorrhage has not been demonstrated. OBJECTIVE: To compare the accuracy of MRI and CT for detection of acute intracerebral hemorrhage in patients presenting with acute focal stroke symptoms. DESIGN, SETTING, AND PATIENTS: A prospective, multicenter study was performed at 2 stroke centers (UCLA Medical Center and Suburban Hospital, Bethesda, Md), between October 2000 and February 2003. Patients presenting with focal stroke symptoms within 6 hours of onset underwent brain MRI followed by noncontrast CT. MAIN OUTCOME MEASURES: Acute intracerebral hemorrhage and any intracerebral hemorrhage diagnosed on gradient recalled echo (GRE) MRI and CT scans by a consensus of 4 blinded readers. RESULTS: The study was stopped early, after 200 patients were enrolled, when it became apparent at the time of an unplanned interim analysis that MRI was detecting cases of hemorrhagic transformation not detected by CT. For the diagnosis of any hemorrhage, MRI was positive in 71 patients with CT positive in 29 (P<.001). For the diagnosis of acute hemorrhage, MRI and CT were equivalent (96% concordance). Acute hemorrhage was diagnosed in 25 patients on both MRI and CT. In 4 other patients, acute hemorrhage was present on MRI but not on the corresponding CT--each of these 4 cases was interpreted as hemorrhagic transformation of an ischemic infarct. In 3 patients, regions interpreted as acute hemorrhage on CT were interpreted as chronic hemorrhage on MRI. In 1 patient, subarachnoid hemorrhage was diagnosed on CT but not on MRI. In 49 patients, chronic hemorrhage, most often microbleeds, was visualized on MRI but not on CT. CONCLUSION: MRI may be as accurate as CT for the detection of acute hemorrhage in patients presenting with acute focal stroke symptoms and is more accurate than CT for the detection of chronic intracerebral hemorrhage.

Clinical-radiological severity mismatch phenomenon: patients with severe neurological deficits without matching infarction on computed tomographic scan.

OBJECTIVE: The objective was to determine the long-term outcome of patients with severe persistent neurological deficits without a large infarction on computed tomographic (CT) scan. METHODS: We analyzed the prospectively collected data as part of the randomized, placebo controlled trial in patients with ischemic stroke presenting within 3 hours of symptom onset. Volume of infarction was measured from CT scan acquired at 3 months. Favorable outcome defined by no significant or slight disability on a modified Rankin scale at 12 months. We determined the outcome of patients with National Institutes of Health Stroke Scale score (NIHSS score) ≥ 10 at 24 hours. RESULTS: Of the 277 patients with NIHSS score ≥ 10 at 24 hours, 88 (32%) met the criteria of clinical-radiological severity mismatch. Compared with patients with NIHSS score ≥ 10 with infarct volume ≥ 20 cc, the patients with NIHSS score ≥ 10 and infarct volume <20 cc were older but there were no differences in the gender, race or vascular risk factors. Patients with clinical-radiological severity mismatch were more likely to have a favorable outcome at 12 months compared with those without mismatch (odd ratio 4.3, 95% confidence interval 1.5-12.6, P = .0063) after adjusting for potential confounders. CONCLUSIONS: We observed that approximately one-fourth of patients with severe neurological deficits have clinical-radiological severity mismatch. Such patients appear to have a high rate of favorable outcomes at 1 year.