Kyung-Yul Lee

Chorea associated with non-ketotic hyperglycemia and hyperintensity basal ganglia lesion on T1-weighted brain MRI study: a meta-analysis of 53 cases including four present cases.

BACKGROUND Chorea associated with non-ketotic hyperglycemia and high signal intensity lesions on T1-weighted brain magnetic resonance images (C-H-BG) is recognized as a unique syndrome that affects elderly women exclusively. However, its overall clinical features are unclear. MATERIAL AND METHODS The literature describing patients with C-H-BG from 1985 to 2001 was reviewed using MEDLINE. Their clinical features and those of four patients with C-H-BG at this hospital were analyzed. RESULTS This study included 49 patients from the literature and four patients at this hospital. Their mean age at the onset was 71.1 years (range=22-92 years). Women were affected more frequently than men (men/women=17:30). The mean serum glucose level measured after the onset of chorea was 481.5 mg/dl (ranging from 169 to 1264), HbA1c level was 14.4% (ranging from 9.9 to 19.2), and the serum osmolarity was 305.9 mmol/kg (ranging from 291 to 335). Forty-seven patients developed hemichorea. Six patients developed bilateral chorea, and magnetic resonance imaging (MRI) showed bilateral basal ganglia lesions. MRI showed that putamen was involved in all cases (isolated putamen=31 patients, additional basal ganglia lesions=22 patients). None had lesions confined to the caudate nucleus or the globus pallidus. In all, except one, the anterior limb of the internal capsule was spared. Follow-up MRI studies were performed in 22 patients. In most, hemichorea improved along with the disappearance of the lesions. In 39 patients, chorea had ameliorated completely. The remaining 14 cases showed some improvement during the follow-up period. The chorea recurred in seven patients. CONCLUSION C-H-BG is a benign disorder affecting the elderly. It affects men much more frequently than has been reported. The high signal intensity basal ganglia lesion on the T1-weighted brain MRI study was reversible, and correlated with the clinical improvement in chorea.

Early recanalization after intravenous administration of recombinant tissue plasminogen activator as assessed by pre-and post-thrombolytic angiography in acute ischemic stroke patients

Background and Purpose— Recanalization rates after the intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment have been poorly studied in acute stroke. Methods— CT angiography was performed before IV rt-PA in all patients and digital subtraction angiography was undertaken for intra-arterial thrombolysis in cases of no improvement after rt-PA infusion. Results— Forty-five patients were treated with IV rt-PA. Initial CT angiography showed relevant arterial occlusions in 35 patients. Recanalization after rt-PA therapy was demonstrated by digital subtraction angiography in 7 of the 31 patients with the occlusion on initial CT angiography: 2/16 in the internal carotid or proximal middle cerebral artery, 3/11 in the distal middle cerebral artery and 2/4 in the basilar artery occlusion. Conclusions— The early recanalization rate after IV rt-PA use was very low in cases with large proximal arterial occlusions. CT angiography before IV rt-PA may be useful for the prediction of its efficacy.

Blood–Brain Barrier Disruption in Humans Is Independently Associated With Increased Matrix Metalloproteinase-9

Background and Purpose— Matrix metalloproteinases (MMP) may play a role in blood–brain barrier (BBB) disruption after ischemic stroke. We hypothesized that plasma concentrations of MMP-9 are associated with a marker of BBB disruption in patients evaluated for acute stroke. Methods— Patients underwent MRI on presentation and ≈24 hours later. The MRI marker, termed hyperintense acute reperfusion injury marker (HARM), is gadolinium enhancement of cerebrospinal fluid on fluid-attenuated inversion recovery MRI. Plasma MMP-9 and tissue inhibitor of matrix metalloproteinase-1 were measured by enzyme-linked immunosorbent assay. Logistic regression models tested for predictors of HARM on 24-hour follow-up scans separately for MMP-9 and the ratio of MMP-9 to TIMP-1. Results— For the 41 patients enrolled, diagnoses were: acute ischemic cerebrovascular syndrome, 33 (80.6%); intracerebral hemorrhage, 6 (14.6%); stroke mimic, 1 (2.4%); and no stroke, 1 (2.4%). HARM was present in 17 (41.5%) patients. In model 1, HARM was associated with baseline plasma MMP-9 concentration (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.001–1.019; P=0.033). In model 2, HARM was associated with the ratio of MMP-9 to tissue inhibitor of matrix metalloproteinase-1 (OR, 4.94; 95% CI, 1.27–19.14; P=0.021). Conclusions— Baseline MMP-9 was a significant predictor of HARM at 24-hour follow-up, supporting the hypothesis that MMP-9 is associated with BBB disruption. If the association between MMP-9 and BBB disruption is confirmed in future studies, HARM may be a useful imaging marker to evaluate MMP-9 inhibition in ischemic stroke and other populations with BBB disruption.

Distal hyperintense vessels on FLAIR: An MRI marker for collateral circulation in acute stroke?

Background: Hyperintense vessels (HV) on fluid-attenuated inversion recovery imaging are frequently observed in acute ischemic stroke patients. However, the exact mechanism and clinical implications of this sign have not yet been clearly defined. The features of HV and its relevance to other imaging factors are presented here. Methods: Prominence and location of HV were documented in 52 consecutive patients with middle cerebral artery (MCA) territory infarction, before treatment with IV recombinant tissue plasminogen activator. Pretreatment ischemic lesion volume, perfusion lesion volume, and vessel occlusion were determined in addition to recanalization status and ischemic lesion volume on follow-up imaging. NIH Stroke Scale (NIHSS) was used as a measure of clinical severity. Results: HV distal to arterial occlusion was observed in 73% of patients; more frequent in proximal than distal MCA occlusion patients. Among the 38 patients with proximal MCA occlusion, initial perfusion lesion volume was comparable among patients with different grade distal HV. However, patients with more prominent distal HV had smaller initial, 24-hour, and subacute ischemic lesion volumes and lower initial NIHSS scores. Conclusions: The presence of distal hyperintense vessels before thrombolytic treatment is associated with large diffusion–perfusion mismatch and smaller subacute ischemic lesion volumes in patients with proximal middle cerebral artery occlusion. DWI = diffusion-weighted imaging; FLAIR = fluid-attenuated inversion recovery; GRE = gradient recalled echo; HV = hyperintense vessels; MCA = middle cerebral artery; MRA = magnetic resonance angiography; MTT = mean transit time; NIHSS = NIH Stroke Scale; PWI = perfusion-weighted imaging; rt-PA = recombinant tissue plasminogen activator; TE = echo time; TI = inversion time; TIMI = thrombolysis in myocardial infarction; TR = repetition time.

Immediate reocclusion following a successful thrombolysis in acute stroke: A pilot study

Immediate reocclusion after successful thrombolysis was angiographically examined in 29 consecutive stroke patients. The reocclusion, which was associated with a high-grade residual stenosis of initially perfused arteries, occurred in four patients. IV abciximab successfully dissolved the thrombus in all four patients. Rapid thrombotic reocclusion after successful thrombolysis is commonly observed in patients after an acute stroke. Administration of abciximab may lead to reperfusion of the reoccluded artery.

Frequency and Significance of Cardiac Sources of Embolism in the TOAST Classification

Background: This study was aimed at determining the frequency and coexistent patterns of high- and medium-risk cardiac sources of embolism (CSE) as defined by the Trial of ORG 10172 in the Acute Stroke Treatment (TOAST) classification system and at investigating how identified CSE contributed to this classification. Methods: We analyzed data from 2,482 patients with acute cerebral infarctions who registered in the Yonsei Stroke Registry over a 10-year period. Cardiac sources were divided into high- and medium-risk groups based on the TOAST classification. Results: Of the 2,482 patients, 1,130 (46%) underwent echocardiographic studies. At least one CSE was detected in 629 patients (25%). Atrial fibrillation was the most common high-risk CSE. Patent foramen ovale, spontaneous echo contrast and congestive heart failure comprised most of the medium-risk CSE. Atrial fibrillation frequently accompanied coexistent CSE (69%) such as spontaneous echo contrast, congestive heart failure, and left atrial/appendage thrombus, while patent foramen ovale was detected in isolation in more than 90% of the patients. Patients with a high-risk CSE were more likely to be diagnosed with cardioembolism (83%) than patients with only a medium-risk CSE (58%). Conclusions: Our study elucidated the frequency and various coexistent patterns of CSE in Korean stroke patients as defined by the TOAST classification system. In addition, we have demonstrated a higher correlation between high-risk CSE and cardioembolism than with medium-risk CSE and cardioembolism.

Rescue treatment with abciximab in acute ischemic stroke

In acute ischemic stroke, reocclusion after an initially successful thrombolysis treatment can occur and is associated with increased morbidity and mortality. The authors present the successful use of abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, in a patient with a thrombotic occlusion of the proximal middle cerebral artery, which was refractory to combined IV and intra-arterial thrombolysis and percutaneous intracranial balloon angioplasty.

Prediction of long-term outcome by percent improvement after the first day of thrombolytic treatment in stroke patients

BACKGROUND We investigated a method for assessing early improvement and predictive factors of early and late outcomes in patients receiving thrombolytic therapy. METHODS A total of 160 consecutive patients who received thrombolytic therapy were included in the study. Using National Institutes of Health Stroke Scale (NIHSS) scores, percent improvement [(baseline NIHSS score-24-hour NIHSS score)/baseline NIHSS score x 100] was calculated and compared with delta (baseline NIHSS score-24-hour NIHSS score) and with major neurological improvement (MNI, NIHSS score of 0-1 or >or=8 point improvement at 24 h) by receiver operating characteristic (ROC) curve analysis. Finally, we investigated the independent predictors of improvement at 24 h after the thrombolytic therapy and of favorable 3-month outcome (modified Rankin scale score 0-2). RESULTS By pairwise comparison of ROC curves, percent improvement was stronger than delta (p=0.004) and MNI (p<0.001) in predicting long-term outcome. First day improvement (FDI), defined as greater than 20% improvement, was a strong predictor of favorable 3-month outcome (OR 12.55, 95% CI 5.41-29.10). Recanalization (OR 3.30, 95% CI 1.28-8.45), absence of carotid T occlusion (OR 0.09, 95% CI 0.02-0.42) and hemorrhagic transformation (OR 0.25, 95% CI 0.09-0.73) were independent predictors of FDI. Independent predictors of favorable 3-month outcome were FDI, current smoking, absence of carotid T occlusion and hemorrhagic transformation. CONCLUSIONS Percent improvement at 24 h after thrombolytic therapy is a useful surrogate marker for predicting the long-term outcome. Our findings highlight the importance of early stroke management.

Persistent increase of matrix metalloproteinases in cerebrospinal fluid of tuberculous meningitis.

Matrix metalloproteinase (MMP)-2 and MMP-9 were analyzed by gelatin zymography and an enzyme-linked immunosorbent assay (ELISA) in a cerebrospinal fluid (CSF) from patients with tuberculous meningitis (n=24), acute aseptic meningitis (n=23) and the control (n=10). The MMP-2 and MMP-9 levels were significantly higher in the samples from the tuberculous meningitis patients than those from either the aseptic meningitis patients or the controls. In tuberculous meningitis, the patients with late neurologic complications had higher MMP-2 and MMP-9 levels than those without. The persistent increase in the MMP-2 and MMP-9 levels was associated with the development of complications following tuberculous meningitis. Inhibiting the MMPs may be an effective strategy for preventing or reducing the complications in tuberculous meningitis.

Safety and outcome after thrombolytic treatment in ischemic stroke patients with high-risk cardioembolic sources and prior subtherapeutic warfarin use

BACKGROUND Hemorrhage is a major complication of thrombolytic treatment. Concerns have been raised about the risk of hemorrhage in patients having received warfarin. Therefore, different indications for thrombolytic treatment are in use for stroke patients on warfarin. However, it remains uncertain whether the prior warfarin use actually increases their risk of bleeding in patients treated with thrombolysis. METHODS This study included 179 consecutive patients who had high-risk cardioembolic sources and received thrombolytic treatment. Patients were treated with intravenous thrombolytic agents, or underwent intraarterial thrombolysis if their international normalized ratio (INR) was ≤1.7. We compared the frequency of bleeding complications between patients with prior warfarin use and those without. We also investigated whether there were differences in functional outcome and recanalization rates between them. RESULTS A prior warfarin use was present in 28 patients (15.6%). Although INR levels were higher in the prior warfarin group, the frequency of bleeding complications was not different between patients who received prior warfarin and those who did not. No differences were observed in patients with or without prior warfarin use, for successful recanalization rate (Thrombolysis in Myocardial Infarction grade 2 or 3), mortality, or modified Rankin score (≤2) at 3months. CONCLUSIONS Thrombolytic therapy for patients who previously received warfarin and had an INR≤1.7 did not affect bleeding risk, clinical outcome, or recanalization rate. Our data suggest that patients with a history of prior warfarin use may be safely treated with thrombolytic agents when their INR levels are low.