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Dong-Wha Kang

Publications and source records attributed to Dong-Wha Kang.

At least 19 recordsLinked to original sources
PubMed2007

Early recurrent ischemic lesions on diffusion-weighted imaging in symptomatic intracranial atherosclerosis.

BACKGROUND: Prior observations have shown that early recurrent ischemic lesions (ERILs) on diffusion-weighted imaging occur frequently within the first week after an index stroke. OBJECTIVE: To investigate differential patterns of ERILs among stroke subtypes, particularly intracranial large-artery atherosclerosis (IC-LAA). DESIGN: Retrospective study. SETTING: Tertiary university hospital. PATIENTS: We included 133 patients who experienced an acute ischemic stroke and who underwent initial diffusion-weighted imaging within 24 hours and subsequent diffusion-weighted imaging within 7 days after onset, and whose stroke subtype was IC-LAA, extracranial LAA (EC-LAA), or cardioembolism (CE). MAIN OUTCOME MEASURE: Early recurrent ischemic lesions were defined as new ischemic lesions on follow-up diffusion-weighted imaging, separate from the index stroke lesion. RESULTS: Early recurrent ischemic lesions were observed in the following proportions: 50.9% (28/55) in the IC-LAA group, 47.4% (9/19) in the EC-LAA group, and 44.1% (26/59) in the CE group. Early recurrent ischemic lesions in the IC-LAA group had the following characteristics: (1) they occurred mostly (27 [96.4%] of 28) in the pial area of the same vascular territory as the index stroke; (2) they were more frequently observed in a higher grade of stenosis than in milder stenosis (P<.001), whereas ERILs in the EC-LAA group were not related to the degree of stenosis; (3) they were not associated with subsequent recanalization, whereas ERILs in the CE group were mostly associated with subsequent recanalization (P<.001); and (4) they were more closely associated with clinical recurrence than in the EC-LAA or CE group (P=.02). CONCLUSION: Early recurrent ischemic lesions in the IC-LAA group are relatively frequent and have different patterns than in the EC-LAA or CE group.

Aged↗
PubMed2006

Fluoxetine is not effective in the treatment of post-stroke fatigue: a double-blind, placebo-controlled study.

BACKGROUND AND PURPOSE: Although post-stroke fatigue (PoSF) is common, pharmacological interventions to improve PoSF have rarely been carried out. The purpose of the present study was to evaluate the therapeutic effect of fluoxetine on PoSF. METHODS: We studied 83 consecutive outpatients with PoSF at an average of 14 months after the onset of stroke. The presence of post-stroke depression, post-stroke emotional incontinence and post-stroke anger proneness was also evaluated with the use of a standardized questionnaire. The presence of PoSF and pre-stroke fatigue was assessed. The visual analogue scale (VAS) and Fatigue Severity Score (FSS) were used to assess PoSF. The subjects were given either 20 mg/day of fluoxetine (n = 40) or placebo (n = 43) for 3 months. Follow-up evaluations were done 3 and 6 months after the beginning of the treatment. RESULTS: The initial mean fatigue VAS score and the mean overall FSS score were 5.4 +/- 2.0 and 4.4 +/- 1.2, respectively. There were no differences in the number of patients with PoSF between the fluoxetine group and the placebo group at 3 and 6 months after the treatment. The percent changes in VAS scores and FSS at all follow-up assessments were not significantly different either. However, fluoxetine significantly improved post-stroke emotional incontinence (p < 0.05) and post-stroke depression (p = 0.05) in the patients with PoSF. CONCLUSIONS: Fluoxetine does not improve PoSF, although some concomitant emotional disturbances improved significantly. Our results suggest that PoSF may be associated with diverse etiologies but not closely related to serotonergic dysfunction. Further studies are required to elucidate the causative factors and to find an appropriate treatment for PoSF.

Affective Symptoms↗
PubMed2006

Is 15 mm size criterion for lacunar infarction still valid? A study on strictly subcortical middle cerebral artery territory infarction using diffusion-weighted MRI.

BACKGROUND AND PURPOSE: The 'lacunar hypothesis' has been challenged, since small (diameter <15 mm) subcortical infarcts can be produced by middle cerebral artery disease (MCAD) or cardioembolism (CE), while a larger infarct can occur without evidence of MCAD or CE. We sought to assess whether the lacunar hypothesis based on size is still valid. METHODS: We studied 118 patients who were admitted within 72 h after stroke onset and had acute deep subcortical MCA territory infarcts detected by diffusion-weighted MRI, and who had undergone angiography (mostly MR angiography). Stroke mechanisms were arbitrarily categorized regardless of lesion size: (1) MCAD when there was a corresponding MCA lesion; (2) internal carotid artery disease (ICAD) when there was a significant (>50%) ipsilateral ICAD; (3) CE when there was emboligenic heart disease without MCAD or ICAD, and (4) small vessel disease (SVD) when there was neither CE nor MCAD. SVD was further divided into definite SVD (dSVD, longest diameter <15 mm) or probable SVD (pSVD, longest diameter > or =15 mm). RESULTS: Seventy-three patients (62%) had SVD, of which 38 (32%) had pSVD and 35 (30%) dSVD. Thirty-three patients (28%) had MCAD, five (4%) CE, and seven (6%) ICAD. The infarct diameter in MCAD was not larger than in SVD (p = 0.35), and there was no difference in clinical features or risk factors between MCAD and SVD, or between pSVD and dSVD. CE was distinguished from SVD by its larger size and cortical symptoms. CONCLUSIONS: There are no clinical and lesion-size differences between MCAD and SVD, suggesting that there seems to be no rationale for the 15 mm size criterion for lacunar or small-vessel infarction.

Adolescent↗
PubMed2006

Acute-stage evolution of watershed infarction assessed on diffusion-weighted MR imaging.

BACKGROUND: To investigate acute stage (<5 days) evolution of the watershed infarction (WI) on diffusion-weighted (DW) magnetic resonance (MR) imaging and to evaluate the role of perfusion MR imaging in predicting the progression of watershed infarction. METHODS: Twenty-eight patients with acute WI within 24 h after symptom onset were selected for this study. Criterion for WI was based on DW images. We assessed the infarct volume changes between the initial and follow-up (mean: 2.2 days) DW images. Perfusion images were obtained in 20 patients at the initial work-up and sensitivity, specificity, and accuracy of perfusion-diffusion mismatch in predicting severe infarct progression were evaluated. Clinical outcome was assessed by using National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). RESULTS: Infarct volumes on initial and follow-up DW images were 8.6+/-7.7 cm3 and 20.2+/-27.0 cm3, respectively. Twenty-one cases showed no or slight increment (<15 cm3) of infarct volume on follow-up MR imaging and seven cases showed severe progression (>15 cm3 increment). Among 20 cases in which perfusion maps were obtained, 5 cases showed perfusion-diffusion mismatch: among those, 4 developed severe progression of infarction. Severe progression group showed higher follow-up NIHSS score and poor outcome by 90-day mRS score. CONCLUSION: WI usually begins as a small volume lesion, and progression of infarction during the acute stage is usually limited in most cases. Perfusion imaging may have an important role in predicting severe infarct progression in WI.

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PubMed2006

Silent ischemic lesion recurrence on magnetic resonance imaging predicts subsequent clinical vascular events.

BACKGROUND: Previous studies identified a high frequency of silent ischemic lesion recurrence on magnetic resonance imaging (MRI) after an index stroke. OBJECTIVE: To investigate whether ischemic lesion recurrence on MRI predicts subsequent clinical events. DESIGN: Retrospective cohort study. SETTING: General community hospital. Patients We recruited 120 patients who experienced an acute ischemic stroke (IS) and who underwent initial MRI within 24 hours of onset and subsequent MRI on day 5. Of those patients, 68 underwent follow-up MRI up to 90 days after onset. MAIN OUTCOME MEASURES: Early silent lesion recurrence was defined as new asymptomatic ischemic lesions on 5-day MRI, and late silent lesion recurrence was defined as those on 30- or 90-day MRI. Patients were followed up for recurrent vascular events by interviews. RESULTS: Among the 104 patients (86.7%) who had available clinical outcome data, 35 (33.7%) had early silent lesion recurrence; 15 (22.1%) of 68 patients had late silent lesion recurrence. Of the patients, 8 experienced a recurrent IS, 3 experienced a transient ischemic attack, and 3 had vascular deaths during a mean +/- SD follow-up of 19.3 +/- 9.0 months. For recurrent IS as a clinical end point, late silent lesion recurrence independently predicted recurrent IS (odds ratio, 6.55; 95% confidence interval, 1.09-39.55) by the Cox proportional hazards model. For combined clinical end points, early (odds ratio, 3.19; 95% confidence interval, 1.02-10.00) and late (odds ratio, 8.09; 95% confidence interval, 1.29-50.91) silent lesion recurrences independently predicted clinical recurrent IS, transient ischemic attack, or vascular deaths. CONCLUSION: These data suggest that silent ischemic lesion recurrence on MRI may be a potential surrogate marker of clinical recurrence.

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PubMed2006

The thickness and texture of temporal bone in brain CT predict acoustic window failure of transcranial Doppler.

BACKGROUND AND PURPOSE: Although transcranial Doppler (TCD) is useful for evaluation and treatment of ischemic stroke, temporal acoustic window failure (TAWF) limits its application. We performed this study to reveal whether initial brain CT of acute stroke patients predicted TAWF. METHODS: We performed TCD in 92 acute ischemic stroke patients (57 males, aged 38-84 years) with brain CT scans. We measured the thickness (BTW) and evaluated the texture of the temporal bone in acoustic windows shown in the CT scan with the use of picture archiving and communication system. The bone mineral density (BMD) of the vertebral bodies, femurs, and whole body was also measured. RESULTS: Doppler signals were adequately obtained in 121 (65.8%) of the 184 middle cerebral arteries (MCA) from both cerebral hemispheres. BTW and inhomogeneity of temporal bone, besides age, sex, and hypercholesterolemia, was strongly correlated with TAWF. BMD was not directly correlated with TAWF, but inhomogeneous temporal bone was correlated with lower BMD scores. If the brain CT scan showed thick (BTW >or= 2.7 mm) and inhomogeneous temporal bone, the possibility of TAWF was 93.5%, while if brain CT scan showed thin (BTW < 2.7 mm) and homogenous temporal bone, it was only 5.4%. CONCLUSIONS: The texture as well as the thickness of the temporal bone was the most important determinant of TAWF. When acute stroke patients had thin and homogeneous temporal bones in initial brain CT scan, TAWF was very rare, and loss of MCA signals on TCD specifcally indicated the absence of blood flow in MCA.

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PubMed2005

Correlation of coronary and cerebral atherosclerosis: difference between extracranial and intracranial arteries.

BACKGROUND: A difference with regard to the correlation with coronary atherosclerosis (CAS) between extracranial carotid atherosclerosis (ECAS) and intracranial cerebral atherosclerosis (ICAS) has been assumed but not proven clearly by direct comparison within the same population. METHODS: A consecutive series of 246 patients undergoing coronary artery bypass graft surgery were reviewed. The severity of CAS was estimated as a CAS score based on coronary angiography. The presence of ECAS and ICAS was screened by transcranial Doppler and carotid duplex sonography, and confirmed by magnetic resonance angiography. RESULTS: The CAS scores in patients with ECAS were observed to be higher than those in patients without ECAS (10.62+/- 4.80 vs. 9.45+/- 4.25; p=0.054 on the Mann-Whitney U test). The difference in CAS scores was smaller between patients with and without ICAS (10.41+/- 4.44 vs. 9.66+/- 4.49; p=0.201). Similar patterns were observed on comparing the correlation of ECAS and ICAS with a quartile of the CAS score. An advanced CAS, which was generated by collapsing the quartiles of the CAS score into 75th percentile or less and more than the 75th percentile, was significantly associated with ECAS, but not with ICAS. These associations remained unchanged after adjustments had been made for age, sex, hypertension, diabetes mellitus, hyperlipidemia, smoking and a history of stroke or transient ischemic attack. CONCLUSIONS: This study suggests that the correlation of CAS with ECAS is stronger than that of CAS with ICAS, and this difference is independent of the classic risk factors for atherosclerosis.

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PubMed2005

Fluoxetine treatment in poststroke depression, emotional incontinence, and anger proneness: a double-blind, placebo-controlled study.

BACKGROUND AND PURPOSE: The efficacy and safety of the selective serotonin reuptake inhibitor fluoxetine have rarely been studied in the treatment of poststroke emotional disturbances. METHODS: Stroke patients (152) who had poststroke depression (PSD), emotional incontinence (PSEI), or anger proneness (PSAP) were studied. PSD was evaluated by Beck Depression Inventory and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, PSEI by Kim's criteria, and PSAP was assessed by Spielberger Trait Anger Scale. Subjects were randomly given either fluoxetine 20 mg/day (n=76) or placebo (n=76) for 3 months. Follow-up evaluations were done 1, 3, and 6 months after the beginning of the treatment. The primary outcome measurement was the scores of emotional disturbances at each follow-up assessment. The secondary outcome measurements were the percentage changes of the scores and the subjective responses of the patients. RESULTS: Although patients in the fluoxetine group more often dropped out because of adverse effects, fluoxetine administration was generally safe. Fluoxetine significantly improved PSEI and PSAP, whereas no definitive improvement of PSD was found. Improvement of PSAP was noted even at 3 months after the discontinuation of the treatment. CONCLUSIONS: Fluoxetine is efficacious in the treatment of PSEI and PSAP. Its effect on PSD is not solidly confirmed.

Aged↗
PubMed2005

Lesion patterns and stroke mechanism in atherosclerotic middle cerebral artery disease: early diffusion-weighted imaging study.

BACKGROUND AND PURPOSE: Patterns and mechanisms of stroke in patients with atherosclerotic middle cerebral artery (MCA) disease remain unclear. We sought to identify lesion patterns and stroke mechanisms associated with MCA disease using early diffusion-weighted imaging (DWI). METHODS: We reviewed 185 acute ischemic stroke patients who had (1) symptomatic lesions located in the unilateral MCA territory on DWI performed within 48 hours of symptom onset, and (2) either corresponding MCA disease, internal carotid artery disease, or cardioembolism. Acute DWI lesion patterns were classified as (1) single (small perforator <2 cm; large perforator > or =2 cm; pial; large territorial; border-zone) and (2) multiple. RESULTS: MCA disease was diagnosed in 63 patients, 32 (50.8%) of whom showed multiple lesions. Concomitant perforator and pial infarcts (14/63, P<0.001), concomitant perforator, pial, and border-zone infarcts (9/63, P<0.001), and single small perforator infarcts (12/63, P=0.001) were identified more often in patients with MCA disease than in those with cardioembolism or internal carotid artery disease. Small perforator infarcts were more common in patients with milder stenosis than with severe stenosis or occlusion of MCA (P<0.001). Whether they occurred singly or in addition to other lesions, pial infarcts were identified more often in patients with severe stenosis or occlusion of MCA (P=0.001). CONCLUSIONS: Perforating artery infarcts, whether single or occurring in addition to pial or border-zone infarcts, are lesion patterns specific for MCA disease. This suggests that local branch occlusion and coexisting distal embolization may be a common stroke mechanism in patients with MCA disease.

Adolescent↗
PubMed2005

Significance of susceptibility vessel sign on T2*-weighted gradient echo imaging for identification of stroke subtypes.

BACKGROUND AND PURPOSE: In contrast to platelet-rich white thrombi, red thrombi in the heart are rich in fibrin and trapped erythrocytes. The magnetic susceptibility effect of deoxygenated hemoglobin in red thrombi may result in hypointense signals on T2*-weighted gradient echo imaging (GRE). We tested the hypothesis that a GRE susceptibility vessel sign (SVS) is specific for cardioembolic stroke. METHODS: This retrospective study examined data from acute ischemic stroke patients who underwent diffusion-weighted imaging, GRE and magnetic resonance angiography (MRA) within 24 hours of stroke onset and who had symptomatic occlusion of large intracranial arteries in the circle of Willis. Hypointense signals within vascular cisterns on GRE corresponding to symptomatic vascular occlusion were termed "GRE SVS." Recanalization was assessed on follow-up MRA performed within 7 days of onset. The relationships between GRE SVS and stroke subtypes and subsequent recanalization were explored. RESULTS: Of the 95 patients who met the inclusion criteria, GRE SVS was observed in 45 (47.4%). GRE SVS was more commonly associated with cardioembolic stroke patients (31 of 40, 77.5%) than with other stroke subtypes (14 of 55, 25.5%; P<0.001). In 66 patients who underwent follow-up MRA, GRE SVS was associated with subsequent recanalization (P<0.001). Multivariate analysis showed that GRE SVS was an independent predictor of cardioembolic stroke and subsequent recanalization (odds ratio, 10.75 and 4.26; 95% CI, 3.68 to 31.47 and 1.12 to 16.30). CONCLUSIONS: GRE SVS may predict cardioembolic stroke and subsequent recanalization. Identifying clot composition may be important in choosing the optimal treatment based on clot characteristics.

Adult↗
PubMed2005

MRI screening before standard tissue plasminogen activator therapy is feasible and safe.

BACKGROUND AND PURPOSE: MRI screening for thrombolytic therapy may improve patient selection. Alternatively, it may excessively delay treatment and thereby lead to worse outcomes. We hypothesized that times to treatment and outcomes in a stroke center with immediate MRI access and interpretation would not differ from those of the typical clinical practice. METHODS: We compared the results of 120 consecutive patients treated with intravenous tissue plasminogen activator (tPA) within 3 hours of onset at our center with those of the 2 largest multicenter registries of tPA use. In addition to standard criteria, MRI specific eligibility criteria were applied in 97 patients. MRI was not performed in 23 patients because of contraindications to MRI or late patient arrival (>2.5 hours). Outcomes were the modified Rankin Scale (mRS) obtained at 3 months. RESULTS: Times to treatment (median door-to-needle time 81.5 minutes; median onset-to-needle time 135 minutes) and outcomes (mRS 0 to 1, 40.8%; mRS 0 to 2, 47.5%) were not inferior to those of the typical clinical practice. Door-to-needle time was shorter in computed tomography (CT) screening (67.5+/-22.5 minutes; n=23) than in MRI screening (86.8+/-21.5 minutes; n=97; P<0.001). However, outcomes were not different between MRI screening (mRS 0 to 1, 42.3%; mRS 0 to 2, 49.5%) and CT screening (mRS 0 to 1, 34.8%; mRS 0 to 2, 39.1%). Neither times to treatment nor MRI screening was predictive of outcomes. CONCLUSIONS: These data demonstrate that MRI screening before tPA therapy is feasible and not associated with unacceptable times to treatment or outcomes.

Adult↗
PubMed2005

Aphasia following striatocapsular infarction may be explained by concomitant small cortical infarct on diffusion-weighted imaging.

BACKGROUND: The underlying mechanism of aphasia following striatocapsular infarction (SCI) remains controversial. We hypothesized that aphasia resulting from SCI might be associated with concomitant cortical lesions, which can be demonstrated by diffusion-weighted imaging (DWI). METHODS: We analyzed 24 patients with left SCI who underwent DWI and MR angiography within 2 days after the onset. Aphasia was assessed by the modified Korean version of the Boston Diagnostic Aphasia Examination test. RESULTS: DWI showed the presence of additional ischemic lesions involving the cortical areas in 13 of 24 SCI patients (54%). Ten patients (42%) showed aphasia. All 10 patients with aphasia had cortical lesions in addition to SCI (p = 0.0002), whereas 21% (3/14) of the nonaphasic patients had additional cortical lesions. Conventional MRI did not reveal the presence of corresponding acute cortical lesions in any of the aphasic patients. There was no difference between the patients with and without aphasia in terms of their stroke etiology. CONCLUSIONS: Our data suggest that aphasia due to SCI in the acute stage may be attributed to direct cortical injury, whose presence can be demonstrated by DWI, even though it might be invisible on conventional imaging.

Aged↗
PubMed2005

Diagnostic and prognostic value of early MR Imaging vessel signs in hyperacute stroke patients imaged <3 hours and treated with recombinant tissue plasminogen activator.

BACKGROUND AND PURPOSE: Analogous to the CT hyperattenuated vessel sign (HMCAS), MR imaging may show hypo- or hyperintense vessels in acute ischemic stroke (AIS) patients. We assessed the diagnostic and prognostic strength of early MR imaging vessel signs in AIS patients treated with intravenous thrombolysis (IVT) within 3 hours of the onset of symptoms. METHODS: We studied AIS patients both treated with IVT and stroke MR imaged within 3 hours of the onset of symptoms and at 2 hours and 24 hours after treatment. We assessed the presence or absence of early vessel signs (hyperintense fluid-attenuated inversion recovery sign [FLAIR HVS]; gradient-echo susceptibility vessel sign [GRE SVS]) compared with a combined MR angiography/perfusion-weighted imaging reference and their strength for predicting clinical outcome (favorable vs. poor, independent vs. dependent, or dead, death), recanalization (by clot composition and flow), and hemorrhage in uni- and multivariate analysis. RESULTS: Fifty-six patients (age range, 76 years +/- 13 years; median National Institutes of Health stroke scale score [NIHSSS], 11) met the inclusion criteria. Forty-four patients (78.6%) had a vessel occlusion at baseline; 22 of them (50%) recanalized. Nineteen patients (33.9%) suffered some form of intracranial hemorrhage (ICH), 24 patients (42.9%) had an independent outcome, 18 patients (32.1%) a favorable outcome, and 14 patients died. Compared with our combined reference for vessel status PWI/MRA, the sensitivities of CT HMCAS, FLAIR HVS, and GRE SVS were 40%, 66%, and 34%, respectively, and improved during the hours that followed. Localization was accurately reflected by FLAIR HVS but not by GRE SVS. Only NIHSSS and age were independent predictors for recanalization and all clinical outcomes in multiple logistic regression analysis. CONCLUSION: Although early vessel signs can be helpful in the diagnosis of intravascular disease, they do not independently predict recanalization, ICH, or any of the three clinical outcomes in a multivariate logistic regression model. Thrombus composition as reflected by signal intensity characteristics on GRE and FLAIR does not predict the therapeutic effect of IVT.

Aged↗
PubMed2004

Diffusion-weighted MRI and 99mTc-HMPAO SPECT in delayed relapsing type of carbon monoxide poisoning: evidence of delayed cytotoxic edema.

BACKGROUND: Carbon monoxide (CO) is a common cause of poisoning, and its sequelae include a progressive (25%) and a delayed relapsing form (75%). We report the diffusion-weighted MRI (DWI) findings in the delayed relapsing form of CO poisoning and characterize the types of edema. METHODS: From November 1, 2000 to June 1, 2003, 5 consecutive patients (2 men, 3 women, range of age: 54-67 years), who had the delayed relapsing type of CO poisoning, underwent DWI, conventional MRI, MR angiography and SPECT. CO poisoning was diagnosed by the presence of a typical clinical history, an abnormally increased level of serum carboxyhemoglobin and MRI findings. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T(2)-weighted echo-planar imaging. RESULTS: DWI showed high signal intensities in bilateral periventricular white matter, in the splenium of the corpus callosum, in internal capsules, and brainstem showing moderately decreased ADC values. In the globus pallidus, the ADC values were rather increased with low signal intensities on DWI. Brain SPECT showed decreased perfusion in bilateral white matter and some parts of the cerebral cortex, which correlated well with the DWI findings. CONCLUSIONS: We suggest that prominent, symmetric restricted diffusion can occur in periventricular white matter, brainstem, and corpus callosum after the delayed relapsing type of CO poisoning. Delayed cytotoxic edema can occur in this setting, which provides a new guidance for the pathogenesis of CO poisoning and the differential diagnosis of white matter diseases.

Aged↗
PubMed2004

Early magnetic resonance imaging findings in patients receiving tissue plasminogen activator predict outcome: Insights into the pathophysiology of acute stroke in the thrombolysis era.

We measured ischemic brain changes with diffusion and perfusion MRI in 42 ischemic stroke patients before and 2 hours (range approximately 1.5 to 4.5 hours) after standard intravenous tissue plasminogen activator (tPA) therapy. The median time from stroke onset to tPA was 131 minutes. Clinical and MRI variables (change in perfusion and/or diffusion weighted lesion volume) were compared between those with excellent outcome defined as 3-month modified Rankin score (mRS) of 0 to 1 and those with incomplete recovery (mRS >1). In multivariate logististic regression analysis, the most powerful independent predictor for excellent outcome was improved brain perfusion: hypoperfusion volume on mean transit time (MTT) map decrease >30% from baseline to 2-hour post tPA scan (p=0.009; odds ratio [95% confidence interval], 20.7 [2.1-203.9]). Except for age < 70 years, no other baseline clinical or imaging variable was an independent predictor of outcome. We propose MTT lesion volume decrease more than 30% 2 hours after tPA as an early marker of long-term clinical benefit of thrombolytic therapy.

Adult↗
PubMed2004

Early blood-brain barrier disruption in human focal brain ischemia.

Loss of integrity of the blood-brain barrier (BBB) resulting from ischemia/reperfusion is believed to be a precursor to hemorrhagic transformation (HT) and poor outcome. We used a novel magnetic resonance imaging marker to characterize early BBB disruption in human focal brain ischemia and tested for associations with reperfusion, HT, and poor outcome (modified Rankin score >2). BBB disruption was found in 47 of 144 (33%) patients, having a median time from stroke onset to observation of 10.1 hours. Reperfusion was found to be the most powerful independent predictor of early BBB disruption (p = 0.018; odds ratio, 4.09; 95% confidence interval, 1.28-13.1). HT was observed in 22 patients; 16 (72.7%) of those also had early BBB disruption (p < 0.001; odds ratio, 8.11; 95% confidence interval, 2.85-23.1). In addition to baseline severity (National Institutes of Health Stroke Scale score >6), early BBB disruption was found to be an independent predictor of HT. Because the timing of the disruption was early enough to make it relevant to acute thrombolytic therapy, early BBB disruption as defined by this imaging biomarker may be a promising target for adjunctive therapy to reduce the complications associated with thrombolytic therapy, broaden the therapeutic window, and improve clinical outcome.

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PubMed2004

Acute stroke patients are being underfed: a nitrogen balance study.

INTRODUCTION: Patients with acute neurological illness may be hypercatabolic. The Harris-Benedict Equation (HBE) is used to estimate energy needs in acute stroke. A "stress factor" for stroke does not exist, and it is not known if the HBE accurately estimates the energy expenditure needs in acute ischemic or hemorrhagic stroke. We sought to assess nitrogen balance in patients with acute stroke and to determine the variables associated with negative nitrogen balance. MATERIALS AND METHODS: This was a case series, single-center study. Eligibility criteria included acute stroke requiring enteral nutrition, tolerating tube feedings at goal, normal urine output, and no underlying catabolic illness. Enteral feeding was adjusted to meet HBE requirements. After 24 hours of goal feeding, a 12-hour urine collection for nitrogen excretion was done. We determined if any of the following variables were associated with negative nitrogen balance: gender, glucose 6.6 mmol/L or more, age 80 years or older, National Institutes of Health Stroke Scale (NIHSS) 20 or higher, mechanical ventilation, and diabetes mellitus. RESULTS: We studied 27 patients (10 with intracranial hemorrhages and 17 with ischemic strokes) during an 18-month period. The median age was 80 (range: 48-90), and the median NIHSS was 19 (range: 4-38). The median time to feeding was 2 days (range: 1-8), the median time from onset to nitrogen balance was 5 days (range: 2-11), and the median interval between initiation of feeding and nitrogen collection was 2 days (range: 1-5)Negative nitrogen balance was seen in 12 of 27 (44%) patients. There was no relation between age, NIHSS, stroke type, admission glucose, history of diabetes, and mechanical ventilation use and nitrogen balance. Only 11 of 27 patients were anabolic. CONCLUSION: Critically ill stroke patients are being underfed using the current methods to estimate caloric needs. Hypercatabolism is common in acute stroke; clinical variables do not seem to allow prediction of this catabolic state.

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