Angiographic features, collaterals, and infarct topography of symptomatic occlusive radiation vasculopathy: a case-referent study.

BACKGROUND AND PURPOSE: Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes. METHODS: We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern. RESULTS: ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups. CONCLUSIONS: ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.

MRI of cardiac iron overload.

Transfusion therapy has greatly improved the survival of transfusion dependent thalassemia major (TM) patients; however, the resultant iron load damages tissues including the heart, liver and endocrine organs. Among these, heart complication still remains the leading cause of mortality. Myocardial iron deposition can occur independently of other solid organ involvement; conversely, the heart may be spared despite heavy siderosis in other tissues. Iron chelation treatment diminishes the risk of hemosiderosis; however, the chelation treatment has its own toxicities and might not be available to all patients due to costs. Close monitoring of individual organ iron concentration and function is thus important for optimization of individual patient care. This review outlines the importance and clinical significance of recently available MRI techniques for monitoring cardiac iron load.

Frequency and predictors of proxy-confirmed post-stroke cognitive complaints in lacunar stroke patients without major depression.

OBJECTIVE: Many lacunar stroke patients complained of cognitive decline after stroke. This study aims to investigate the factors underlying post-stroke cognitive complaints in these patients. METHODS: Seventy-five consecutive lacunar stroke patients without major depression were recruited for the study. Stroke severity was measured using NIHSS score and MRI was performed during the acute admission period. At 3 months, objective psychometric performance and depressive symptoms were assessed. Post-stroke cognitive complaints were corroborated by a proxy. Using logistic regression we examined the contribution of demographic features, stroke severity, objective psychometric scores, depressive symptoms, and imaging features (white matter lesion volume and infarct measures) to post-stroke cognitive complaints. RESULTS: Thirty-two (42.7%) patients had post-stroke cognitive complaints. Patients with post-stroke cognitive complaints had more depressive symptoms and worse psychometric performance than those without. In the multivariate logistic regression model, only the severity of depressive symptoms was independently associated with post-stroke cognitive complaints. CONCLUSIONS: This study suggests that post-stroke cognitive complaints are frequent among lacunar stroke patients without major depression and are prominently determined by the subclinical depressive symptomatology.

Papillary lesions of the breast--accuracy of core biopsy.

AIMS: To assess the accuracy of diagnosing papillary breast lesions in core needle biopsy. METHODS AND RESULTS: One hundred biopsy specimens of papillary breast lesions were reviewed and compared with the final excisional diagnoses. The discordant biopsy specimens were stained for oestrogen receptor (ER), cytokeratin (CK) 14 and p63, and these specimens were reclassified based on these results. The overall core biopsy accuracy, false-positive and false-negative rate were 79%, 5% and 16%, respectively. A benign core biopsy specimen diagnosis gave a false-negative rate of 10%, and malignant core biopsy specimen diagnosis did not give any false-positive results. Using homogeneous ER (epithelial), positive CK14 (epithelial) and p63 (myoepithelial) immunoreactivity as benign criteria, the discordant rate was reduced by 30% and 69% when using all three or two of these three criteria for diagnosis. However, false-positive and -negative cases could not be totally eliminated. CONCLUSIONS: Immunohistochemistry is helpful in core biopsy diagnosis of papillary breast lesions, but some cases remained misdiagnosed.

International reproducibility of single breathhold T2* MR for cardiac and liver iron assessment among five thalassemia centers.

PURPOSE: To examine the reproducibility of the single breathhold T2* technique from different scanners, after installation of standard methodology in five international centers. MATERIALS AND METHODS: Up to 10 patients from each center were scanned twice locally for local interstudy reproducibility of heart and liver T2*, and then flown to a central MR facility to be rescanned on a reference scanner for intercenter reproducibility. Interobserver reproducibility for all scans was also assessed. RESULTS: Of the 49 patients scanned, the intercenter reproducibility for T2* was 5.9% for the heart and 5.8% for the liver. Local interstudy reproducibility for T2* was 7.4% for the heart and 4.6% for the liver. Interobserver reproducibility for T2* was 5.4% for the heart and 4.4% for the liver. CONCLUSION: These data indicate that T2* MR may be developed into a widespread test for tissue siderosis providing that well-defined and approved imaging and analysis techniques are used.

Effects of statins on progression of subclinical brain infarct.

BACKGROUND: Subclinical brain infarct (SBI) is associated with subsequent stroke and cognitive decline. A longitudinal epidemiological study suggests that statins may prevent development of SBI. We investigated the effects of statins upon development of brain infarct by performing a post-hoc analysis of the Regression of Cerebral Artery Stenosis (ROCAS) study. METHODS: The ROCAS study is a randomized, double-blind, placebo-controlled study evaluating the effects of simvastatin 20 mg daily upon progression of asymptomatic middle cerebral artery stenosis among stroke-free individuals over 2 years. A total of 227 subjects were randomized to either placebo (n = 114) or simvastatin 20 mg daily (n = 113). The number of brain infarcts as detected by MRI was recorded at baseline and at the end of the study. The primary outcome measure was the number of new brain infarcts at the end of the study. RESULTS: Among the 227 randomized subjects, 33 (14.5%) had SBI at baseline. At the end of the study, significantly fewer subjects in the active group (n = 1) had new brain infarcts compared with the placebo group (n = 8; p = 0.018). The new brain infarcts of subjects in the active group were subclinical. Among the placebo group, the new brain infarcts of 3 subjects were symptomatic while those of the remaining 5 subjects were subclinical. Among putative variables, multivariate regression analysis showed that only the baseline number of SBIs (OR = 6.27, 95% CI 2.4-16.5) and simvastatin treatment (OR = 0.09, 95% CI 0.01-0.82) independently predicted the development of new brain infarcts. CONCLUSIONS: Consistent with findings of the epidemiological study, our study suggests that statins may prevent the development of a new brain infarct.

Would self-expanding stent occlude middle cerebral artery perforators?

BACKGROUND AND PURPOSE: A major concern of intracranial stenting is perforator infarction. It is unclear whether the sustained radial force of a self-expanding stent or subsequent stent restenosis would cause late occlusion of perforators. METHODS: We compared the baseline and poststent (>or=4 months) MRI scans of patients who underwent self-expanding stenting for recurrent ischemic symptoms attributed to a MCA stenosis >or=60%. New infarcts in the ipsilateral striatocapsular region were recorded. RESULTS: MCA stenting was technically successful in 23 of 24 recruited patients. No new perforator territory infarct was found in follow-up MRI scans of all recruited patients. Postoperatively, all patients reported no further TIA or stroke over a median follow-up of 15 months. CONCLUSIONS: The use of a self-expanding stent in patients with high-grade MCA stenosis may not pose a major risk to the perforators.

Lesion patterns and stroke mechanisms in concurrent atherosclerosis of intracranial and extracranial vessels.

BACKGROUND AND PURPOSE: Concurrent atherosclerosis of the intracranial and extracranial cerebrovascular system is common in Asians. The typical lesion patterns and the mechanisms of stroke in patients with concurrent stenoses are unclear. This study aimed to determine these stroke features of such patients in Hong Kong. METHODS: We conducted a cross-sectional cohort study in a university hospital from January 2002 to December 2003. Consecutive Chinese patients with acute ischemic stroke underwent CT brain, MRI brain (with MR angiography and diffusion-weighted imaging sequences), and carotid duplex. RESULTS: In total, 251 patients were included in the analysis. Of these, 109 (43%) had concurrent stenoses. Patients who had concurrent stenoses, as compared with those without concurrent stenoses, had more symptomatic stenoses (84% versus 58%; OR, 4.0; 95% CI, 2.1 to 7.3; P<0.001), more concomitant perforating artery infarct, pial infarct, and borderzone infarct (14% versus 4%; OR, 3.6; 95% CI, 1.4 to 9.7; P=0.007), more multiple diffusion-weighted imaging lesions (55% versus 37%; OR, 2.1; 95% CI, 1.3 to 3.4; P=0.005), and more infarcts in the territory of the leptomeningeal branches of middle cerebral artery (26% versus 13%; OR, 2.2; 95% CI, 1.2 to 4.3; P=0.01). In multivariate regression analysis, smoking; prior stroke; the presence of concomitant pial infarct, pial infarct, and borderzone infarcts; multiple diffusion-weighted imaging lesions; and symptomatic stenoses were significantly associated with concurrent stenoses. Among patients with concurrent stenoses, those who had tandem lesions, as compared with those who had nontandem lesions, had more perforating artery infarct and borderzone infarcts (27% versus 8%; OR, 4.3; 95% CI, 0.9 to 19.8; P=0.04); more concomitant pial infarct, pial infarct, and borderzone infarcts (18% versus 0%; P=0.02), and more multiple diffusion-weighted imaging lesions (65% versus 23%; OR, 6.2; 95% CI, 2.2 to 17.2; P<0.001). Infarcts in the territory of middle cerebral artery leptomeningeal branches and symptomatic stenoses were more common in patients with tandem lesions. CONCLUSIONS: Concomitant perforating artery infarct, pial infarct, and borderzone infarcts; multiple diffusion-weighted imaging lesions, and infarcts in the leptomeningeal branches of the middle cerebral artery were more common in patients with concurrent stenoses, especially those with tandem lesions. This study suggested that the combination of hemodynamic compromise attributable to concurrent stenoses and artery-to-artery embolization is a common stroke mechanism in these patients.

Symptomatic ostial vertebral artery stenosis: treatment with drug-eluting stents--clinical and angiographic results at 1-year follow-up.

PURPOSE: To evaluate the feasibility and preliminary results of using paclitaxel-eluting stents for angioplasty and to treat symptomatic atherosclerotic ostial vertebral artery (VA) stenosis. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this prospective study. Nine men and one woman (average age, 65.9 years +/- 11.6 [standard deviation]) were included. Inclusion criteria were as follows: (a) Patients had angiographic evidence of VA ostial stenosis of 50% or more or stenosis of more than 45% if the contralateral VA was occluded. (b) Refractory vertebrobasilar ischemia, such as a stroke or transient ischemic attack, occurred while patients were taking one antiplatelet medication with optimal cardiovascular risk factor control. (c) Patients did not have another substantial vertebrobasilar stenotic lesion in the same territory. The primary end point was procedure safety, defined as mortality and permanent neurologic morbidity 30 days after stent placement. The secondary end point was clinical effectiveness, defined as recurrent vertebrobasilar ischemic symptoms within 12 months after stent placement and restenosis greater than or equal to 50% of the treated VA segment within 12 months after stent placement. RESULTS: The degree of stenosis ranged from 46% to 83% (mean, 67.3% +/- 11.9). The technical success rate was 100%. Procedure-related complication rate, mortality rate, and permanent neurologic morbidity rate at 30-day follow-up were 0%. At 12-month follow-up, no patient reported recurrent vertebrobasilar ischemic symptoms or had VA restenosis. CONCLUSION: This pilot study suggests that use of paclitaxel-eluting stents in angioplasty and to treat symptomatic atherosclerotic ostial VA stenosis are feasible and promising in terms of potential safety and effectiveness in prevention of recurrent ischemia and restenosis. These results could be helpful in the formulation of a larger prospective randomized controlled trial.

Statins for asymptomatic middle cerebral artery stenosis: The Regression of Cerebral Artery Stenosis study.

BACKGROUND: The progression of cerebral atherosclerosis increases the risk of stroke and vascular events. Given the known benefits of statins in retarding coronary and carotid atherosclerosis progression, we studied the effects of statins on asymptomatic middle cerebral artery (MCA) stenosis progression. METHODS: We conducted a randomized, double-blind, placebo-controlled study to evaluate the effects of simvastatin on the progression of MCA stenosis among stroke-free individuals who had mild to moderately elevated LDL cholesterol (3.0-5.0 mmol/l). Two hundred and twenty-seven subjects were randomized to either placebo (n = 114) or simvastatin 20 mg daily (n = 113). The severity of MCA stenosis at baseline and at the end of the study was graded by MRA into normal, minimal (<10%), mild (10-49%), moderate (50-90%) and severe (>90%). The primary outcome was the change in grading of MCA stenosis over 2 years. RESULTS: At the end of the study, the LDL cholesterol level decreased by 1.43 and 0.12 mmol/l for the active and placebo groups, respectively (p < 0.001). There was no significant difference in the proportion of patients having stable, progressive and regressive MCA stenosis between the placebo (72, 22 and 6%) and active groups (78.6, 15.5 and 5.8%). The all-cause mortality was significantly lower in the active group (n = 0) relative to the placebo group (n = 7, p = 0.014). Any clinical events were also lower in the active group (n = 5) than in the placebo group (n = 13, p = 0.052). CONCLUSIONS: Simvastatin 20 mg daily had no apparent effect upon the evolution of asymptomatic MCA stenosis over 2 years.

The validity, reliability and clinical utility of the Hong Kong Montreal Cognitive Assessment (HK-MoCA) in patients with cerebral small vessel disease.

BACKGROUND/AIMS: To evaluate the psychometric properties of the Hong Kong Montreal Cognitive Assessment (HK-MoCA) in patients with cerebral small vessel disease (SVD). METHODS: 40 SVD patients and 40 matched controls were recruited. Concurrent and criterion validity, inter-rater and test-retest reliability, internal consistency of the HK-MoCA were examined and clinical observations were made. RESULTS: Performance on the HK-MoCA was significantly predicted by both executive (beta = 0.23, p = 0.013) and non-executive (beta = 0.64, p < 0.001) composite scores. It differentiated SVD patients from controls (area under the curve = 0.81, p < 0.001) with an optimal cutoff at 21/22. Reliability, internal consistency and clinical utility were good. CONCLUSION: The HK-MoCA is a useful cognitive screening instrument for use in SVD patients.

Emotional incontinence and executive function in ischemic stroke: a case-controlled study.

Frontal and basal ganglia infarcts and executive dysfunction are thought to be involved in the pathophysiology of poststroke emotional incontinence (PSEI). The study examined whether patients with PSEI have more frontal and/or basal ganglia infarcts and impairment in executive function. A total of 516 Chinese patients with acute ischemic stroke consecutively admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong were screened for PSEI 3 months after the index stroke. According to Kim's criteria, 39 (7.6%) had PSEI. Thirty-nine stroke patients without PSEI served as matched control group. The PSEI group had significantly more frontal and/or basal ganglia infarcts, had lower Chinese Frontal Assessment Battery scores, required more time to complete the Stroop Test, and made more omission and commission errors in the Go-NoGo test. There was no significant correlation between frontal or basal ganglia infarcts and executive function. The correlation between frontal infarct and severity of PSEI was .420. Further follow-up and functional imaging studies are warranted to explore the relationship between PSEI, brain infarcts, and executive dysfunction. (JINS, 2009, 15, 62-68.).

Magnetic resonance imaging assessment of cardiac and liver iron load in transfusion dependent patients.

BACKGROUND: Magnetic resonance imaging (MRI) is an emerging tool to assess organ-specific iron load in patients with transfusion dependent anemia. OBJECTIVE: We performed MRI T2 star (T2*) assessment in 44 transfusion dependent patients to study the prevalence of cardiac and liver iron overload and the relationship of T2* measurement with various clinical and biochemical parameters. RESULT: Mean age of the study subjects was 19.9 years (range 8.8-32.3) and the mean cardiac T2* was 23.4 +/- 13.8 msec. Fifty percent of the subjects had abnormal cardiac T2* (below 20 msec). Cardiac T2* was not found to have any correlation with serum ferritin or liver T2*. Liver T2* value was abnormal in 79% of the subjects and it correlated inversely with both current and 12 months average serum ferritin (r = -0.44, P = 0.003; r = -0.46, P = 0.002). Clinical parameters including age, duration of transfusion, age starting iron chelation therapy, and ratio between transfusion volume and desferrioxamine dosage were not correlated with cardiac and liver T2*. CONCLUSION: We conclude that iron overload in heart and liver is common in our transfusion dependent patients. Liver T2* has inverse correlation with serum ferritin. Cardiac T2* does not have any correlation with the various clinical and biochemical parameters.

Different distribution patterns of cerebral microbleeds in acute ischemic stroke patients with and without hypertension.

BACKGROUND: Cerebral microbleeds (CMBs) were found in patients with and without hypertension. We aimed to investigate different distribution patterns of CMBs in patients with and without hypertension. METHODS: We examined acute ischemic stroke patients using a standardized MRI protocol that included T(1), T(2) and gradient-echo T(2)*. Clinical and imaging characteristics were collected from all patients. RESULTS: Among 998 patients, CMBs were detected in 273 patients (27.3%). Of these, 62 did not have hypertension (22.7%). The incidence of CMBs among patients without hypertension (62/335, 18.5%) was lower than among those with hypertension (211/663, 31.8%; p < 0.01). The location of CMBs in patients without hypertension was limited to the cortical-subcortical (CSC) region in 40.3% (25/62) compared to 20.4% of those with hypertension (43/211; p = 0.01). No significant difference was found between CMB locations within the intra-CSC region in both groups. The severity of white matter changes and systolic blood pressure on admission were found to be independent predictors for CMBs in patients without hypertension. CONCLUSIONS: CMBs in patients with and without hypertension have different distribution patterns and may have a different pathogenesis. Blood pressure controlling is important in both groups because systolic blood pressure is an independent predictor of CMBs in patients without hypertension.

Preliminary findings of external counterpulsation for ischemic stroke patient with large artery occlusive disease.

BACKGROUND AND PURPOSE: We aimed to investigate the feasibility and therapeutic effect of external counterpulsation (ECP) in ischemic stroke. METHODS: The trial was a randomized, crossover, assessment-blinded, proof-of-concept trial. ECP treatment consisted of 35 daily 1-hour sessions. Patients were randomized to either early (ECP weeks 1 to 7 and no ECP weeks 8 to 14) or late group (no ECP weeks 1 to 7 and ECP weeks 8 to 14). Primary outcomes were an overall change in National Institutes of Health Stroke Scale (NIHSS) and cerebral blood flow estimated by color velocity imaging quantification. Secondary outcomes were change in NIHSS, color velocity imaging quantification, favorable functional outcome (modified Rankin scale, 0 to 2), and stroke recurrence at weeks 7 and 14, respectively. RESULTS: Fifty patients were recruited. At week 7, there was a significant change in NIHSS (early 3.5 vs late 1.9; P=0.042). After adjusting for treatment sequence, ECP was associated with a favorable trend of change in NIHSS of 2.1 vs 1.3 for non-ECP (P=0.061). Changes of color velocity imaging quantification were not significant but tended to increase with ECP. At week 14, a favorable functional outcome was found in 100% of early group patients compared to 76% in the late group (P=0.022). CONCLUSIONS: ECP is feasible for ischemic stroke patients with larger artery disease.

Patient-specific decision-making for warfarin therapy in nonvalvular atrial fibrillation: how will screening with genetics and imaging help?

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) accounts for a majority of long-term morbidity and mortality associated with bleeding while on warfarin. Both ICH and warfarin-related ICH appear to have a genetic component. Furthermore, advanced neuroimaging using MRI can now identify individuals at increased risk of ICH. We explore whether screening strategies that include genetic profiling and neuroimaging might improve the safety of chronic anticoagulation for atrial fibrillation by identifying individuals from whom warfarin should be withheld. METHODS: We used a Markov state transition decision model. Effectiveness was measured in quality-adjusted life-years. Data sources included the English language literature using MEDLINE searches and bibliographies from selected articles along with empirical data from our institutions. The base case was a 69-year-old man with newly diagnosed nonvalvular atrial fibrillation. RESULTS: For patients at average risk for thromboembolic events and known to possess a hypothetical genetic profile increasing risk for warfarin ICH, anticoagulation remains the preferred strategy until the relative hazard of ICH exceeds 23.8. Genetic profiling would be favored for patients at low risk of thromboembolism (1.5% per year) if the hypothetical gene variant(s) conferred a relative risk of ICH >4.1. Screening strategies in which patients underwent genotyping and MRI before anticoagulation did not improve aggregate patient outcomes unless the predictive power of MRI exceeded current best guess estimates and patients were at low to moderate risk of thromboembolism. CONCLUSIONS: Currently identified genetic markers of bleeding risk do not confer a risk of ICH sufficiently high to warrant routine genetic testing for patients at average risk of thromboembolism. Even if patients undergo screening with MRI as well as genotyping, currently available data on the role of MRI on risk of ICH and warfarin ICH do not support use of these tests for withholding anticoagulation in patients with atrial fibrillation.

Left ventricular systolic dyssynchrony is a predictor of cardiac remodeling after myocardial infarction.

OBJECTIVES: We sought to determine whether early assessment of left ventricular (LV) dyssynchrony by tissue Doppler imaging may predict progressive ventricular enlargement and cardiac dysfunction after acute myocardial infarction (MI). METHODS: Forty-seven patients (mean age 59.9 +/- 11.6 years) with normal QRS duration underwent tissue Doppler imaging and contrast-enhanced cardiac magnetic resonance imaging (Ce-MRI) at days 2 to 6, 3 months, and at 1 year after the index MI. Systolic dyssynchrony index (Ts-SD) was calculated from 12 LV segments, and infarct size (IS) by Ce-MRI. RESULTS: The remodeling group (n = 16) (defined as an increase in end-systolic volume > or =10% between 1 year and baseline) had greater initial IS (27.2 +/- 9.6 vs 13.7 +/- 4.1%, P < .001) and Ts-SD (50.9 +/- 12.8 vs 33.6 +/- 7.7 milliseconds, P < .001) than nonremodeling group (n = 31). At 1 year, the remodeling group had progressive increase in Ts-SD and decrease in LV ejection fraction (57.3 +/- 18.5 and 36.0 +/- 7.6%, respectively; both P < .05 vs baseline). Both Ts-SD (odds ratio 1.19 [1.07-1.32], P = .001) and IS (odds ratio 1.65 [1.19-2.29], P = .003) were shown to be independent predictors of progressive LV remodeling. A cutoff value of Ts-SD > or =45 milliseconds predicted LV remodeling at 1 year (sensitivity 90.5%, specificity 90.9%, Area-under-curve 0.907) (P = .0005). CONCLUSIONS: Left ventricular systolic dyssynchrony is a newly identified predictor of chronic LV remodeling after acute MI, which is independent and incremental to conventional assessment and IS as measured by Ce-MRI.

A T2* magnetic resonance imaging study of pancreatic iron overload in thalassemia major.

We studied the utility of pancreatic magnetic resonance imaging (MRI) in 72 thalassemia major patients (21 diabetic, 51 normoglycemic). Diabetic patients were significantly older (p<0.0001) and had smaller pancreas volume (p<0.0001). The two groups were comparable for ferritin and MRI-T2* heart, liver and pancreas. Pancreatic T2* signals were abnormal in 80% of both groups, and correlated with heart T2*. In normoglycemic patients, cardiac T2* and log-pancreatic T2* values correlated with homeostatic model assessments HOMA-B (beta cell reserve), HOMA-IR (insulin resistance) and fasting insulin/C-peptide levels. This suggested that improved chelation may improve beta cell reserve and prevent pancreatic atrophy.

Risk vs benefit of anti-thrombotic therapy in ischaemic stroke patients with cerebral microbleeds.

BACKGROUND: Retrospective studies suggested that cerebral microbleeds (MB) on magnetic resonance images (MRI) increase risk of intracerebral haemorrhage (ICH). OBJECTIVE: To compare the benefit of anti-thrombotic agents in stroke prevention (absolute risk reduction 2.49 -6 %) versus risk of ICH in ischaemic stroke patients with MB. MATERIALS AND METHODS: We prospectively studied patients admitted consecutively for acute ischaemic stroke between 1999 and 2004. MB on MRI were documented. Primary end points were subsequent ICH, recurrent cerebral infarct (CI) and mortality. RESULTS: A total of 908 patients were recruited. MB were identified in 252 (27.8 %) patients. Mean follow-up period was 26.6 +/- 15.4 months. Risk of subsequent ICH increased significantly with quantity of MB: 0.6 % (no MB), 1.9 % (1 MB), 4.6 % (2-4 MB) and 7.6 % (>or= 5 MB) (p < 0.001). There was also a significant increase in mortality from ICH: 0.6 %, 0.9 %, 1.5 % and 3.8 % respectively (p = 0.054). Rate of recurrent CI was 9.6 %, 5.6 %, 21.5 % and 15.2 % respectively (p = 0.226). Mortality from CI and myocardial infarction did not increased with quantity of MB. Survival analyses showed that age, presence of MB, mixed cortical-subcortical distribution of MB were independent predictors of subsequent ICH. CONCLUSION: Risk and mortality of ICH increased with quantity of MB. As tendency to recurrent CI exceed that of ICH, anti-thrombotic agents are still warranted. However, in patients with >or= 5 MB, the high risk and mortality of ICH seem to outweigh the modest benefit of antithrombotic agents. Extra precautions should be taken to minimize risk of ICH. Further studies in patients on Coumadin and assessment of functional outcome are warranted to support these preliminary findings.

Clinical features, topographic patterns on DWI and etiology of thalamic infarcts.

Thalamic infarcts may lead to diverse neurological disturbances, which easily results in misdiagnosis. Diffusion-weighed magnetic resonance imaging (DWI) is sensitive for the early diagnosis of the infarct and identification of the territory involved. The aim of this study was to analyze the clinical features, topographic appearance on DWI and etiology of thalamic infarcts. We reviewed clinical data, vascular risk factors, topographic patterns and etiology of thalamic infarcts. The patients were divided into 2 groups according to DWI patterns: isolated thalamic infarcts (ISO-TH) and combined thalamic infarcts (COM-TH). The former were further subdivided into 2 subgroups: inferolateral isolated thalamic infarcts (INF-TH) and non-inferolateral isolated thalamic infarcts (NON-INF) according to the vascular territories. The Patients were also divided according to etiology based on TOAST classification. The association of clinical features, DWI patterns and etiology was analyzed. Twenty nine patients were included, among which, 23 (79.3%) were ISO-TH and 6 (20.7%) were COM-TH. The most common territory involved in the ISO-TH was inferolateral territory [n=17 (73.9%)], followed by tuberothalamic artery territory [n=3 (13.0%)], and posterior choroidal artery territory [n=2 (8.7%)]. In COM-TH, the most common territory also was the inferolateral territory (n=3), followed by posterior choroidal artery territory (n=1). In 2 patients, the lesions involved more than one vascular thalamic territory. Significant association between small-vessel occlusion (SVO) and ISO-TH (INF-TH+NON-IFN) infarcts were found. Our study suggested that SVO was more prevalent in ISO-TH, and COM-TH needed more etiological examination. DWI might provide meaningful clues about etiology of thalamic infarcts.