79 results on '"Ka-Sing Wong"'
Search Results
2. Association Between the Apolipoprotein E Gene Polymorphism and Atherosclerotic Middle Cerebral Artery Stenosis.
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Zhengsheng Zhang, Xiang-yan Chen, Larry Baum, Ho Keung Ng, Vincent Mok, and Ka Sing Wong
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- 2018
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3. Autonomic Dysfunction Predicts Clinical Outcomes After Acute Ischemic Stroke: A Prospective Observational Study.
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Li Xiong, Ge Tian, Howan Leung, Soo, Yannie O. Y., Xiangyan Chen, Ip, Vincent H. L., Mok, Vincent C. T., Chu, Winnie C. W., Ka Sing Wong, Leung, Thomas W. H., Xiong, Li, Tian, Ge, Leung, Howan, Chen, Xiangyan, and Wong, Ka Sing
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- 2018
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4. Histological Characteristics of Intracranial Atherosclerosis in a Chinese Population: A Postmortem Study.
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Wen Jie Yang, Fisher, Mark, Lu Zheng, Chun Bo Niu, Paganini-Hill, Annlia, Hai Lu Zhao, Yun Xu, Ka Sing Wong, Ho Keung Ng, and Xiang Yan Chen
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ATHEROSCLEROSIS ,IMMUNOSTAINING ,VERTEBRAL artery - Abstract
Background: Anterior and posterior circulation atherosclerosis differ in vascular risk factors and stroke mechanisms. However, few studies have compared the pathological features between these lesions. Using a series of intracranial artery specimens, we characterized the intracranial atherosclerotic lesions and compared pathological features among different arteries of the intracranial vasculature. Methods: Intracranial large arteries of 32 consecutively recruited autopsy cases of Chinese adults aged 45 years or older were examined pathologically using routine histology and immunostaining, to characterize the pathological features of the atherosclerotic lesions. We analyzed middle cerebral arteries (MCAs) (both left and right), vertebral arteries (VAs) (side more affected) and basilar arteries (BAs). Results: Progressive atherosclerotic lesions were present in 91(71%) of the 128 arteries examined. Features of complicated plaques were infrequently detected: plaque hemorrhage was encountered in 12%, neovasculature in 12%, lumen thrombi in 13%, macrophage infiltration in 20%, and calcification in 25% of arteries. Luminal narrowing of MCA was the most severe, followed by VA; the BA least stenotic (37 ± 25 vs. 30 ± 24 vs. 20 ± 20%, all p < 0.05). MCA had more eccentric (vs. concentric) plaques than VA (69 vs. 25%, p = 0.003) and BA (69 vs. 38%; p = 0.03). Lumen thrombi were more frequent in BA, and calcification most commonly occurred in VA atherosclerotic lesions. Conclusion: Intracranial atherosclerotic plaques were commonly present in this sample, but the lesions generally lacked features of complicated plaques. MCA lesions had demonstrable differences compared with VA and BA lesions. Further studies are needed to determine whether these characteristics indicate a distinctive atherosclerotic phenotype for the intracranial vasculature. [ABSTRACT FROM AUTHOR]
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- 2017
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5. Prediction of Recurrent Stroke or Transient Ischemic Attack After Noncardiogenic Posterior Circulation Ischemic Stroke.
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Changqing Zhang, Yilong Wang, Xingquan Zhao, Liping Liu, ChunXue Wang, Yuehua Pu, Xinying Zou, Yuesong Pan, Ka Sing Wong, Yongjun Wang, Zhang, Changqing, Wang, Yilong, Zhao, Xingquan, Liu, Liping, Wang, ChunXue, Pu, Yuehua, Zou, Xinying, Pan, Yuesong, Wong, Ka Sing, and Wang, Yongjun
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- 2017
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6. Impaired cerebral autoregulation: measurement and application to stroke.
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Li Xiong, Xiuyun Liu, Ty Shang, Smielewski, Peter, Donnelly, Joseph, Zhen-ni Guo, Yi Yang, Leung, Thomas, Czosnyka, Marek, Rong Zhang, Jia Liu, Ka Sing Wong, Xiong, Li, Liu, Xiuyun, Shang, Ty, Guo, Zhen-Ni, Yang, Yi, Zhang, Rong, Liu, Jia, and Wong, Ka Sing
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STROKE ,BLOOD pressure ,PERFUSION ,BLOOD flow measurement ,INTRACRANIAL arterial diseases - Abstract
Cerebral autoregulation (CA) is a protective mechanism that maintains cerebral blood flow at a relatively constant level despite fluctuations of cerebral perfusion pressure or arterial blood pressure. It is a universal physiological mechanism that may involve myogenic, neural control as well as metabolic regulations of cerebral vasculature in response to changes in pressure or cerebral blood flow. Traditionally, CA has been represented by a sigmoid curve with a wide plateau between about 50 mm Hg and 170 mm Hg of steady-state changes in mean arterial pressure, defined as static CA. With the advent of transcranial Doppler, measurement of cerebral blood flow in response to transient changes in arterial pressure has been used to assess dynamic CA. However, a gold standard for measuring CA is not currently available. Stroke has been the leading cause of long-term adult disability throughout the world. A better understanding of CA and its response to pathological derangements can help assess the severity of stroke, guide management decisions, assess response to interventions and provide prognostic information. The objective of this review is to provide a comprehensive insight about physiology of autoregulation, measurement methodologies and clinical applications in stroke to help build a consensus for what should be included in an internationally agreed protocol for CA testing and monitoring, and to promote its translation into clinical bedside practice for stroke management. [ABSTRACT FROM AUTHOR]
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- 2017
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7. Transcranial Doppler.
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Sharma, Vijay K., Ka Sing Wong, and Alexandrov, Andrei V.
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- 2016
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8. Biomarkers, Natural Course and Prognosis.
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Arenillas, Juan F., López-Cancio, Elena, and Ka Sing Wong
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- 2016
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9. Stroke Mechanisms.
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Ka Sing Wong, Caplan, Louis R., and Kim, Jong S.
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- 2016
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10. Epidemiology.
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Gorelick, Philip, Ka Sing Wong, and Liping Liu
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- 2016
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11. Recurrent stroke risk and cerebralmicrobleed burden in ischemic stroke and TIA.
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Wilson, Duncan, Charidimou, Andreas, Ambler, Gareth, Fox, Zoe V., Gregoire, Simone, Rayson, Phillip, Toshio Imaizumi, Fluri, Felix, Hiromitsu Naka, Horstmann, Solveig, Veltkamp, Roland, Rothwell, Peter M., Kwa, Vincent I. H., Thijs, Vincent, Yong-Seok Lee, Young Dae Kim, Yining Huang, Ka Sing Wong, Jäger, Hans Rolf, and Werring, David J.
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- 2016
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12. Postmortem Study of Validation of Low Signal on Fat-Suppressed T1-Weighted Magnetic Resonance Imaging as Marker of Lipid Core in Middle Cerebral Artery Atherosclerosis.
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Wen-Jie Yang, Xiang-Yan Chen, Hai-Lu Zhao, Chun-Bo Niu, Bing Zhang, Yun Xu, Ka-Sing Wong, Ho-Keung Ng, Yang, Wen-Jie, Chen, Xiang-Yan, Zhao, Hai-Lu, Niu, Chun-Bo, Zhang, Bing, Xu, Yun, Wong, Ka-Sing, and Ng, Ho-Keung
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- 2016
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13. Magnetic Resonance Imaging of Plaque Morphology, Burden, and Distribution in Patients With Symptomatic Middle Cerebral Artery Stenosis.
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Dieleman, Nikki, Wenjie Yang, Abrigo, Jill M., Winnie Chiu Wing Chu, van der Kolk, Anja G., Siero, Jeroen C. W., Ka Sing Wong, Hendrikse, Jeroen, Xiang Yan Chen, Yang, Wenjie, Chu, Winnie Chiu Wing, Wong, Ka Sing, and Chen, Xiang Yan
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- 2016
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14. Impact of collaterals on the efficacy and safety of endovascular treatment in acute ischaemic stroke: a systematic review and meta-analysis.
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Xinyi Leng, Hui Fang, Leung, Thomas W. H., Chen Mao, Zhongrong Miao, Liping Liu, Ka Sing Wong, Liebeskind, David S., Leng, Xinyi, Fang, Hui, Mao, Chen, Miao, Zhongrong, Liu, Liping, and Wong, Ka Sing
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CEREBROVASCULAR disease ,ENDOVASCULAR surgery ,STROKE treatment ,META-analysis ,SYSTEMATIC reviews - Abstract
Objective: We aimed to investigate the role of pretreatment collateral status in predicting the efficacy and safety of endovascular treatment (EVT) in acute ischaemic stroke due to cervical and/or cerebral arterial occlusions.Methods: Relevant full-text articles published since 1 January 2000, investigating correlations between collateral status and any efficacy or safety outcome in patients undergoing EVT in cohort or case-control studies, or randomised clinical trials, were retrieved by PubMed and manual search. Two authors extracted data from eligible studies and assessed study quality. Risk ratios (RR) were pooled for good versus poor collaterals for outcomes based on a random-effects model. Sensitivity and subgroup analyses were conducted.Results: In total, 35 (3542 participants) and 23 (2652 participants) studies were included in qualitative review and quantitative meta-analysis, respectively. Overall, good pretreatment collaterals increased the rate of favourable functional outcome at 3 months (RR=1.98, 95% CI 1.64 to 2.38; p<0.001), and reduced the risks of periprocedural symptomatic intracranial haemorrhage (RR=0.59, 95% CI 0.43 to 0.81; p=0.001) and 3-month mortality (RR=0.49, 95% CI 0.38 to 0.63; p<0.001), as compared with poor collaterals, in patients with acute ischaemic stroke under EVT. No individual study could alter the estimate of overall effect of collateral status, but there were moderate to significant heterogeneities between subgroups of studies with different modes of EVT, different arterial occlusions and different collateral grading methods.Conclusions: Good pretreatment collateral status is associated with higher rates of favourable functional outcome, and lower rates of symptomatic intracranial haemorrhage and mortality, in patients with acute ischaemic stroke receiving endovascular therapies. [ABSTRACT FROM AUTHOR]- Published
- 2016
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15. Enhancing cerebral perfusion with external counterpulsation after ischaemic stroke: how long does it last?
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Li Xiong, Wenhua Lin, Jinghao Han, Xiangyan Chen, Thomas Leung, Yannie Soo, Ka Sing Wong, Xiong, Li, Lin, Wenhua, Han, Jinghao, Chen, Xiangyan, Leung, Thomas, Soo, Yannie, and Wong, Ka Sing
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ENHANCED external counterpulsation ,STROKE risk factors ,STROKE rehabilitation ,ANTERIOR cerebral artery ,REGULATION of blood pressure ,DISEASES ,CEREBRAL artery physiology ,ARTIFICIAL blood circulation ,BLOOD pressure ,CEREBRAL arteries ,CEREBRAL circulation ,CEREBRAL ischemia ,COMPARATIVE studies ,RESEARCH methodology ,MEDICAL cooperation ,RESEARCH ,STROKE ,TRANSCRANIAL Doppler ultrasonography ,EVALUATION research ,RANDOMIZED controlled trials ,DISEASE complications - Abstract
Objective: External counterpulsation (ECP) is a non-invasive method used to augment cerebral perfusion in ischaemic stroke. We aimed to investigate time-course effects on blood pressure elevation and cerebral blood flow augmentation induced by ECP in ischaemic stroke.Methods: Patients with acute unilateral ischaemic stroke and large artery occlusive disease were recruited to receive 35 daily 1 h ECP treatment sessions. Serial transcranial Doppler monitoring of bilateral middle cerebral arteries was performed on days 3, 5, 7, 10, 14, 21, 28 and 35 after stroke onset. Flow velocity changes before, during and after ECP and continuous beat-to-beat blood pressure data were recorded. The cerebral augmentation index (CAI) is the increase in the percentage of the middle cerebral artery mean flow velocity during ECP compared with baseline.Results: The CAI in patients with stroke was significantly higher on the ipsilateral side and on the contralateral side on day 3 (ipsilateral CAI, 9.3%; contralateral CAI, 7.2%), day 5 (7.0%; 6.7%), day 7 (6.8%; 6.0%), day 10 (6.0%; 5.1%), day 14 (4.7%; 2.6%) and day 21 (4.1%; 2.2%) after stroke onset than that in controls (-2.0%) (all p<0.05). There was a significant trend of decreasing CAI on the ipsilateral and contralateral sides over time after a stroke. Differences in the percentage increase in the mean blood pressure did not change significantly over time in patients with stroke.Conclusions: Blood pressure elevation persists throughout ECP treatment, which consists of 35 sessions. However, cerebral blood flow augmentation may last at least 3 weeks and then appears to return to baseline 1 month after acute stroke onset. [ABSTRACT FROM AUTHOR]- Published
- 2016
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16. Compensatory patterns of collateral flow in stroke patients with unilateral and bilateral carotid stenosis.
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Hui Fang, Bo Song, Bo Cheng, Ka Sing Wong, Yu Ming Xu, Sin Yee Ho, Stella, Xiang Yan Chen, Fang, Hui, Song, Bo, Cheng, Bo, Wong, Ka Sing, Xu, Yu Ming, Ho, Stella Sin Yee, and Chen, Xiang Yan
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CAROTID artery stenosis ,CEREBRAL circulation ,HEMODYNAMICS ,INTERNAL carotid artery ,STROKE ,COLLATERAL circulation ,ULTRASONIC imaging ,BRAIN ,CAROTID artery ,SEVERITY of illness index - Abstract
Background: Collateral pathways are important in maintaining adequate cerebral blood flow in patients with carotid stenosis. We aimed to evaluate the hemodynamic patterns in relation to carotid stenosis in acute stroke patients.Methods: Consecutive 586 stroke patients in a hospital based cohort were included in the present study. Carotid duplex was performed to identify patients with absolute minimal diameter reductions of 50% or greater in their internal carotid arteries (ICAs). Color velocity imaging quantification ultrasound (CVIQ) was used to measure extracranial arterial blood flow volume (BFV) in bilateral common carotid arteries (CCAs) and bilateral vertebral arteries (VAs). The absolute values of BFV and the ratios were compared between patients with and without ICA stenosis.Results: Among 586 acute ischemic stroke patients (mean age: 67.5 ± 12.4y), ICA stenosis was detected in 112 patients (19.1%), including unilateral ICA stenosis in 81 patients (13.8%) and bilateral ICA stenosis in 31 patients (5.3%). Among patients with unilateral ICA stenosis, the BFV in contralateral CCA was significantly higher than that in ipsilateral CCA (325.5 ± 99.8 mL/min vs. 242.2 ± 112.2 mL/min, P < 0.001). Among patients with bilateral ICA stenosis, the sum of BFV in bilateral VAs accounted for 22% of the whole cerebral blood flow, which was significantly higher than that in those without ICA stenosis (14.8%, P < 0.001) or with unilateral ICA stenosis (16.9%, P = 0.007).Conclusions: In patients with unilateral carotid stenosis, contralateral carotid blood flow increases to compensate decreased blood flow, while posterior circulation may compensate for the decreased brain perfusion in those with bilateral carotid stenosis. [ABSTRACT FROM AUTHOR]- Published
- 2016
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17. In Vitro Assessment of Histology Verified Intracranial Atherosclerotic Disease by 1.5T Magnetic Resonance Imaging: Concentric or Eccentric?
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Wen-Jie Yang, Xiang-Yan Chen, Hai-Lu Zhao, Chun-Bo Niu, Yun Xu, Ka-Sing Wong, Ho-Keung Ng, Yang, Wen-Jie, Chen, Xiang-Yan, Zhao, Hai-Lu, Niu, Chun-Bo, Xu, Yun, Wong, Ka-Sing, and Ng, Ho-Keung
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- 2016
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18. Combined external counterpulsation and endovascular stenting treatment for symptomatic vertebrobasilar artery stenosis: two case reports.
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Li Xiong, Xiang Yan Chen, Wai Hong Leung, Thomas, and Ka Sing Wong, Lawrence
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ENHANCED external counterpulsation ,SURGICAL stents ,ARTERIAL stenosis - Abstract
Symptomatic vertebrobasilar artery (VBA) stenosis has a poor prognosis. Intravascular stents provide a new therapeutic approach, but the long-term outcome of stenting compared with medical outcome is controversial. External counterpulsation (ECP) is a noninvasive method to improve perfusion of vital organs. We report two cases of this combination with ECP treatment in addition to receiving endovascular stenting. Two patients experienced posterior ischemic stroke. Digital subtraction angiography revealed a severe basilar or vertebral artery stenosis. Computed tomographic perfusion revealed significantly decreased perfusion of posterior artery territories. Both of them underwent combined ECP treatment and endovascular stenting of the stenosed basilar or vertebral artery, without recurrent stroke within 30 days after stenting. The two patients were independent (modified Rankin scale ≤2) at the 12-month follow-up time. Combined ECP treatment and endovascular stent placement may be effective and safe for patients with symptomatic VBA stenosis who failed aggressive medical treatment. [ABSTRACT FROM AUTHOR]
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- 2015
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19. Apathy and suicide-related ideation 3 months after stroke: a cross-sectional study.
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Wai Kwong Tang, Lara Caeiro, Chieh Grace Lau, Huajun Liang, Vincent Mok, Ungvari, Gabor S, and Ka Sing Wong
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Background: Both apathy and suicide are common in poststroke patients. However, the association between poststroke apathy and suicide-related ideation (SI) in Chinese stroke patients is not clear and poorly understood. The aim of this study was to examine the association between apathy and SI in stroke. Methods: A cross-sectional study was conducted to investigate the association in 518 stroke survivors from Acute Stroke Unit of the Prince of Wales Hospital in Hong Kong. Geriatric Mental State Examination-Version A (GMS) and Neuropsychiatric Inventory-apathy subscale (NPI-apathy) were employed to assess poststroke SI and apathy, respectively. Patients’ clinical characteristics were obtained with the following scales: the National Institutes of Health Stroke Scale (NIHSS), the Mini-Mental State Examination (MMSE), and the Geriatric Depression Scale (GDS). Results: Thirty-two (6.2%) stroke survivors reported SI. The SI group had a significantly higher frequency of NPI-apathy than the non-SI group (31.2% vs 5.3%, p < 0.001). The SI group also had higher GDS scores (10.47 ± 3.17 vs 4.24 ± 3.71, p < 0.001). Regression analysis revealed that NPI-apathy (OR 2.955, 95% CI 1.142-7.647, p = 0.025) was a significant predictor of SI. The GDS score also predicted SI (OR 1.436, 95% CI 1.284-1.606, p < 0.001). Conclusions: The current findings show that poststroke apathy is an independent predictor of SI 3 months after stroke. Early screening for and intervention targeting apathy through medication and psychological treatments may be necessary to improve stroke patients’ apathy and reduce SI. [ABSTRACT FROM AUTHOR]
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- 2015
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20. Apathy and suicide-related ideation 3 months after stroke: a cross-sectional study.
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Wai Kwong Tang, Caeiro, Lara, Lau, Chieh Grace, Huajun Liang, Mok, Vincent, Ungvari, Gabor S., and Ka Sing Wong
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APATHY ,SUICIDE ,STROKE ,CEREBROVASCULAR disease ,SUICIDAL ideation - Abstract
Background: Both apathy and suicide are common in poststroke patients. However, the association between poststroke apathy and suicide-related ideation (SI) in Chinese stroke patients is not clear and poorly understood. The aim of this study was to examine the association between apathy and SI in stroke. Methods: A cross-sectional study was conducted to investigate the association in 518 stroke survivors from Acute Stroke Unit of the Prince of Wales Hospital in Hong Kong. Geriatric Mental State Examination-Version A (GMS) and Neuropsychiatric Inventory-apathy subscale (NPI-apathy) were employed to assess poststroke SI and apathy, respectively. Patients' clinical characteristics were obtained with the following scales: the National Institutes of Health Stroke Scale (NIHSS), the Mini-Mental State Examination (MMSE), and the Geriatric Depression Scale (GDS). Results: Thirty-two (6.2%) stroke survivors reported SI. The SI group had a significantly higher frequency of NPI-apathy than the non-SI group (31.2% vs 5.3%, p < 0.001). The SI group also had higher GDS scores (10.47 ± 3.17 vs 4.24 ± 3.71, p < 0.001). Regression analysis revealed that NPI-apathy (OR 2.955, 95% CI 1.142-7.647, p = 0.025) was a significant predictor of SI. The GDS score also predicted SI (OR 1.436, 95% CI 1.284-1.606, p < 0.001). Conclusions: The current findings show that poststroke apathy is an independent predictor of SI 3 months after stroke. Early screening for and intervention targeting apathy through medication and psychological treatments may be necessary to improve stroke patients' apathy and reduce SI. [ABSTRACT FROM AUTHOR]
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- 2015
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21. Thrombotic thrombocytopenic purpura with concomitant small- and large-vessel thrombosis, atypical posterior reversible encephalopathy syndrome and cerebral microbleeds.
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Wong Li Yu, Thomas Leung, Yannie Soo, Jessamyn Lee, and Ka Sing Wong
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THROMBOPENIC purpura ,WHITE matter (Nerve tissue) ,BASAL ganglia ,THALAMUS - Abstract
We report a case of thrombotic thrombocytopenic purpura (TTP) with uncommon imaging features, namely concomitant small- and large-vessel thrombosis, atypical locations of posterior reversible encephalopathy syndrome (PRES) and microbleeds. A 58-year-old Chinese woman presented with slurred speech and multiple petechiae over lower limbs. Blood tests showed thrombocytopenia. Neuroimaging showed multiple acute small infarcts and PRES in the sub-cortical white matter, basal ganglia, thalamus, brainstem and occipital lobe. Microbleeds were noted. She was treated as TTP with infusion of cryo-reduced plasma (CRP). Patient subsequently developed dense right hemiplegia. Computed tomography of brain demonstrated a new major left middle cerebral artery territory infarct. She was stabilized after 2 weeks of treatment with daily CRP infusion, then received rehabilitation for major stroke. Early recognition of TTP provides the best chance of recovery as most lesions are reversible when TTP was treated. However, concurrent large artery thrombosis could cause major morbidity and mortality. [ABSTRACT FROM AUTHOR]
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- 2015
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22. Subcortical white matter infarcts predict 1-year outcome of fatigue in stroke.
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Wai Kwong Tang, Yang Kun Chen, Hua Jun Liang, Chiu Wing Chu, Winnie, Chung Tony Mok, Vincent, Ungvari, Gabor S., and Ka Sing Wong
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LEUKOENCEPHALOPATHIES ,FATIGUE (Physiology) ,STROKE ,CORONARY disease ,SPONTANEOUS cancer regression - Abstract
Background Fatigue is common in stroke survivors. Lesion location may influence the risk of poststroke fatigue (PSF) but it is uncertain whether location has an impact on the prognosis of PSF. This study examined the association between PSF outcome and infarct location. Methods The study sample comprised 435 Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university affiliated regional hospital in Hong Kong. Three and fifteen months after the onset of the index stroke a research assistant administered the Fatigue Severity Scale (FSS). PSF was defined as a FSS score of 4.0 or above. Of the 139 patients with PSF three months poststroke, 97 (69.8%) attended the 15-month follow-up, when 50 (51.5%) patients still had PSF ('non-remitters') and 47 (48.5%) did not report fatigue ('remitters'). The presence and location of infarcts were evaluated with magnetic resonance imaging. Results In comparison with the remitters, the non-remitters were more likely to have subcortical white matter infarcts (40.0% vs 21.3%, p = 0.046). These infarcts remained an independent predictor of non-remission of PSF in the multivariate analysis, with an odds ratio of 4.208 (p = 0.011). Conclusions The results suggest that subcortical white matter infarcts may influence the outcome of PSF. Further investigations are needed to explore whether infarcts have any impact on the response of PSF to pharmacological or psychological interventions. [ABSTRACT FROM AUTHOR]
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- 2014
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23. Dual antiplatelets reduce microembolic signals in patients with transient ischemic attack and minor stroke: subgroup analysis of CLAIR study.
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Lau, Alexander Y., Yudong Zhao, Chen, Christopher, Leung, Thomas W., Jianhui Fu, Yining Huang, Suwanwela, Nijasri C., Zhao Han, Kay Sin Tan, Ratanakorn, Disya, Markus, Hugh S., and Ka Sing Wong
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Background Short course of dual antiplatelet therapy for early secondary prevention is a promising treatment for patients with minor stroke or transient ischemic attack at high risk of recurrence. Methods We examined the efficacy and safety of dual antiplatelets in patients with transient ischemic attack or minor stroke, defined as National Institute of Health Stroke Scale scores 0–3, in a subgroup analysis of Clopidogrel plus aspirin versus Aspirin alone for Reducing embolization in patients with acute symptomatic cerebral or carotid artery stenosis (CLAIR) study. Microembolic signals on transcranial Doppler monitoring was used as surrogate marker for recurrent stroke risk. Patients with ≥1 microembolic signals at baseline were randomized to receive dual therapy (aspirin 75–160 mg daily and clopidogrel 300 mg day 1 then 75 mg daily) or monotherapy (aspirin 75–160 mg daily) for seven-days. Results Sixty-five of 100 patients recruited had transient ischemic attack or minor stroke: 30 received dual therapy and 35 received monotherapy. Mean onset-to-randomization was 2·3 days in dual therapy group and 3·2 days in monotherapy group (P = 0·03). At day 7, the proportion of patients with ≥1 microembolic signals was 9 of 29 patients in dual therapy group and 18 of 34 patients in monotherapy group (adjusted relative risk reduction 41·4%, 95% CI 29·8–51·1, P < 0·001). The median number of microembolic signals on day 7 was 0 in dual therapy group and 1·0 in monotherapy group (P = 0·046). No patients had intracranial or severe systemic hemorrhage. Conclusions Early dual therapy with clopidogrel and aspirin reduces microembolic signals in patients with minor ischemic stroke or transient ischemic attack, without causing significant bleeding complications. [ABSTRACT FROM AUTHOR]
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- 2014
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24. Distal Single Subcortical Infarction Had a Better Clinical Outcome Compared With Proximal Single Subcortical Infarction.
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Changqing Zhang, Yilong Wang, Xingquan Zhao, David Wang, Liping Liu, Chunxue Wang, Yuehua Pu, Xinying Zou, Wanliang Du, Jing Jing, Yuesong Pan, Ka Sing Wong, and Yongjun Wang
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- 2014
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25. Brainstem infarcts predict REM sleep behavior disorder in acute ischemic stroke.
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Wai Kwong Tang, Hermann, Dirk M., Yang Kun Chen, Hua Jun Liang, Xiang Xin Liu, Winnie Chui Wing Chu, Ahuja, Anil T., Abrigo, Jill, Mok, Vincent, Ungvari, Gabor S., and Ka Sing Wong
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BRAIN stem ,SLEEP disorders ,RAPID eye movement sleep ,DISEASE prevalence ,LEWY body dementia - Abstract
Background Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance in which patients enact their dreams while in REM sleep. The behavior is typically violent in association with violent dream content, so serious harm can be done to the patient or the bed partner. The prevalence of RBD is well-known in Parkinson's disease, Lewy body dementia, and multiple systems atrophy. However, its prevalence and causes in stroke remained unclear. The aim of this study was to determine factors influencing the appearance of RBD in a prospective cohort of patients with acute ischemic stroke. Methods A total of 2,024 patients with first-ever or recurrent acute ischemic stroke were admitted to the Acute Stroke Unit at the Prince of Wales Hospital between January 2010 and November 2011; 775 of them received an MRI scan. Within 2 days of admission, a research nurse collected demographic and clinical data and assessed the severity of each stroke using the National Institute of Health Stroke Scale (NIHSS). One hundred and nineteen of the 775 patients meeting study entry criteria formed the study sample. All eligible participants were invited to attend a research clinic 3 months after the onset of the index stroke. In the attendance, a research assistant administered the MMSE and the 13-item RBD questionnaire (RBDQ). Results Among 119 stroke patients, 10.9% were exhibited RBD, defined as an REM sleep behavior disorder questionnaire score of 19 or above. The proportion of patients with acute brainstem infarct was significantly higher in RBD patients than those without RBD. Compared with patients without RBD, RBD patients were more likely to have brainstem infarcts and had smaller infarct volumes. In a multivariate analysis, in which stroke location and infarct volume were inserted, brainstem infarcts were an independent predictor of RBD (odds ratio = 3.686; P = 0.032). Conclusions The results support the notion of a predominant role of brainstem injury in the development of RBD and suggest that patients with brainstem infarcts RBD should be evaluated by a clinical neurologist. [ABSTRACT FROM AUTHOR]
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- 2014
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26. Learning curve of Wingspan stenting for intracranial atherosclerosis: single-center experience of 95 consecutive patients.
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Chun Ho Yu, Simon, Wai Hong Leung, Thomas, Kwok Tung Lee, and Ka Sing Wong, Lawrence
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VASCULAR surgery ,CEREBRAL arteriosclerosis ,CLINICAL competence ,LONGITUDINAL method ,RESEARCH funding ,SURGICAL stents ,DESCRIPTIVE statistics - Abstract
Background Symptomatic brain hemorrhage was a significant cause of periprocedural stroke or death following stenting in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis trial, which called into question the safety of Wingspan stenting for intracranial atherosclerosis. This study analyzed the role of a learning curve in the safety and outcome of Wingspan stenting from the experience of 95 consecutive patients at a single center. Methods In this prospective study the endpoints were major stroke or death (modified Rankin Scale score >3) within 30 days, other neurological complications, technical procedural problems, technical success in completion of angioplasty and stenting and recurrent ischemic stroke in the corresponding vascular territory after 30 days. Data splitting into quarters was used for learning curve analysis. Results The periprocedural major stroke or death rate was 4.2% (4/95), minor stroke rate was 5.3% (5/95), total 9.5% (9/95). The technical procedural problem rate was 11.6% (11/95) and the technical success rate was 93.7% (89/95). The 89 patients were followed for 38.9 ±22.7 months (median 40.8, range 0.2-72, 3463 patient-months) after stenting. The risk of recurrent ischemic stroke in the corresponding vascular territory was 0.7% per patient per year (2/3463 patient-months). Guidewire- or angioplasty-related hemorrhage was the major cause of periprocedural major stroke or death (3/4, 75%) and did not occur in the last quarter. Periprocedural intracerebral hemorrhage was uncommon and perforator stroke did not occur. Conclusions There may be a learning curve for mastering the safety precautions of Wingspan stenting for intracranial atherosclerosis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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27. Evaluating Intracranial Atherosclerosis Rather Than Intracranial Stenosis.
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Xinyi Leng, Ka Sing Wong, and Liebeskind, David S.
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- 2014
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28. Cerebral Microbleeds as a Predictor of 1-Year Outcome of Poststroke Depression.
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Wai Kwong Tang, Yangkun Chen, Huajun Liang, Winnie Chiu Wing Chu, Vincent Chung Tong Mok, Gabor Sandor Ungvari, and Ka Sing Wong
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- 2014
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29. Geographic and Sex Difference in the Distribution of Intracranial Atherosclerosis in China.
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Yuehua Pu, Liping Liu, Yilong Wang, Xinying Zou, Yuesong Pan, Yannie Soo, Leung, Thomas, Xingquan Zhao, Ka Sing Wong, and Yongjun Wang
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- 2013
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30. Predictors of good functional outcome in counterpulsation-treated recent ischaemic stroke patients.
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Wenhua Lin, Jinghao Han, Xiangyan Chen, Li Xiong, Ho Wan Leung, Thomas W Leung, Yannie Soo, and Lawrence Ka Sing Wong
- Abstract
Objectives: External counterpulsation (ECP) is a non-invasive method being investigated for ischaemic stroke. We aimed to explore predictors of good functional outcome for ECP-treated ischaemic stroke patients who completed a minimum of 10 sessions. Methods: We analysed our ECP registry of ischaemic stroke patients with cerebral large artery stenosis who underwent ECP therapy at the Prince of Wales Hospital from 2004 to 2010. We included 155 patients who completed at least 10 sessions of ECP and had 3-month follow-up data as well as 52 medical controls. Functional outcomes were dichotomised into good outcome (modified Rankin Scale (mRS) 0-2) and bad outcome (mRS 3-6). We compared the differences in two groups in terms of demographics, medical history and parameters of ECP treatment. Results: At 3 months after stroke, 70.5% of patients who finished the whole course of ECP had a good outcome (only 46.5% in the unfinished group and 38.5% in the medical group). Among all 207 recruited cases, 119 (57.5%) patients had a good outcome at 3 months after stroke. Compared with the bad outcome group, patients in the good outcome group were younger and had a lower baseline National Institutes of Health Stroke Scale (NIHSS) and longer ECP therapy duration. Multivariate logistic regression showed that ECP duration (OR 1.032), baseline NIHSS (OR 0.734) and age (OR 0.961) were independent predictors for a favourable outcome. Conclusions: Duration of ECP therapy is first found to be an important predictor for good outcome of ECP-treated ischaemic stroke patients, in addition to the well-known prognostic factors such as age and NIHSS. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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31. Atrophy of the left dorsolateral prefrontal cortex is associated with poor performance in verbal fluency in elderly poststroke women.
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Yang-Kun Chen, Wei-Min Xiao, Defeng Wang, Lin Shi, Chu, Winnie C. W., Mok, Vincent C. T., Ka Sing Wong, Ungvari, Gabor S., and Wai Kwong Tang
- Subjects
ATROPHY ,PREFRONTAL cortex ,EXECUTIVE function ,COGNITION ,STROKE patients ,NERVOUS system regeneration ,SEX differences (Biology) - Abstract
The article presents a study which investigates the association between atrophy in the prefrontal cortex with executive function and verbal fluency in elderly male and female who are poststroke patients. Topics discussed include neural regeneration, sex differences, and brain atrophy. Also mentioned are neuroimaging, magnetic resonance imaging, and cognitive processes.
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- 2013
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32. Angiographic Features, Collaterals, and Infarct Topography of Symptomatic Occlusive Radiation Vasculopathy.
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Zou, Winnie X. Y., Leung, Thomas W., Yu, Simon C. H., Wong, Edward H. C., Leung, S. F., Soo, Yannie O. Y., Ip, Vincent H. L., Chan, Anne Y. Y., Lam, Wynnie W. M., Siu, Deyond Y. W., Abrigo, Jill, Kwok Tung Lee, Liebeskind, David S., and Ka Sing Wong
- Published
- 2013
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33. Prognostic Value of Inflammatory Mediators in 1-Year Outcome of Acute Ischemic Stroke with Middle Cerebral Artery Stenosis.
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Xiping Gong, Xinying Zou, Liping Liu, Yuehua Pu, Yilong Wang, Yuesong Pan, Yannie O. Y. Soo, Thomas W. H. Leung, Xingquan Zhao, Yongjun Wang, and Ka Sing Wong
- Subjects
CORONARY artery stenosis ,INFLAMMATORY mediators ,STROKE treatment ,DISEASE progression ,TREATMENT effectiveness ,C-reactive protein - Abstract
Background and Purpose. Inflammation exists in inception, progression, and reperfusion of acute ischemic stroke. Insightful understanding of correlation in inflammatory mediators and stroke severity with intracranial artery stenosis may improve rational stroke therapy. Methods. We prospectively recruited 977 patients with acute noncardioembolic ischemic stroke with MCA stenosis by MRA as none to mild (<50%), moderate (50-69%), severe (70-99%), or occlusive (100%). The peripheral levels of WBC, homocysteine (HCY), and high sensitivity C-reactive protein (hs-CRP) were recorded. All patients were assessed of 1-year outcome by mRS as favorable (0-2) or poor (3-6). Results. The levels of WBC, HCY, and hs-CRP had no significant differences in patients with categorized MCA stenosis (all P > 0.05). Higher levels of WBC, HCY, and hs-CRP were found in patients with 1-year poor outcome (all P < 0.05), but only hs-CRP is an independent predictor (OR 1.06,95% CI 1.027-1.093, P = 0.0003). The combination of any two of increased hs-CRP (>3mg/L), WBC (>6.91 x 10
9 /L), and HCY (>15 µmol/L) had higher power in predicting 1-year poor outcome than the single elevated mediator. Conclusions. Elevated hs-CRP independently predicts 1-year poor outcome in acute stroke. The combination of increased hs-CRP, WBC, or HCY had a stronger predictive value in poor outcome than individual elevated mediator. [ABSTRACT FROM AUTHOR]- Published
- 2013
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34. Correlation of Large Artery Intracranial Occlusive Disease With Carotid Intima-Media Thickness and Presence of Carotid Plaque.
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Xin Yi Leng, Xiang Yan Chen, Ping Chook, Li Xiong, Wen Hua Lin, Jing Yi Liu, Tomlinson, Brian, Thomas, G. Neil, Tai Hing Lam, Lam, Karen S. L., Cheung, Bernard M. Y., and Ka Sing Wong
- Published
- 2013
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35. Association of a genetic variant in the apolipoprotein A5 gene with the metabolic syndrome in Chinese.
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Kwok Leung Ong, Chao Qiang Jiang, Bin Liu, Ya Li Jin, Tso, Annette W. K., Tam, Sidney, Ka Sing Wong, Tomlinson, Brian, Cheung, Bernard M. Y., Jie Ming Lin, Xiao Jun Yue, Lam, Karen S. L., Tai Hing Lam, and Thomas, Graham Neil
- Subjects
METABOLIC syndrome ,APOLIPOPROTEINS ,CHINESE people ,TRIGLYCERIDES ,CARDIOVASCULAR diseases risk factors ,DISEASES - Abstract
Single nucleotide polymorphisms (SNPs) in the apolipoprotein A5 gene ( APOA5) are associated with hypertriglyceridaemia in our population. We studied the associations of SNPs in APOA5 with the metabolic syndrome (MetS) in the Hong Kong and Guangzhou Chinese. We genotyped five tagging SNPs in 1330 unrelated subjects from the Hong Kong Cardiovascular Risk Factor Prevalence Study cohort with follow-up after a median interval of 6·4 years; 1952 subjects from the Guangzhou Biobank Cohort Study-Cardiovascular Disease Subcohort were used to replicate the findings. The MetS was defined according to the consensus criteria proposed jointly by several organizations in 2009. The SNP rs662799 (−1131T>C) was associated with the MetS (odds ratio = 1·47, P = 0·00082) and the number of its components present (regression coefficient = 0·204, P = 4·6 × 10) after adjusting for age, sex, smoking, drinking and education in Hong Kong subjects at baseline. Similar association of this SNP was found in Hong Kong subjects at follow-up ( P = 0·010 and 0·00021, respectively) and in Guangzhou subjects ( P = 0·0041 and 0·017, respectively). The association of rs662799 with the number of the MetS components was significant regardless of age, sex, obesity and alcohol drinking, but almost disappeared after further adjusting for plasma triglycerides. Our results showed that the −1131T>C polymorphism in APOA5 was associated with the MetS because of its strong effect on plasma triglycerides. This may partly explain the higher cardiovascular risk in people with this polymorphism. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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36. A single nucleotide polymorphism in APOA5 determines triglyceride levels in Hong Kong and Guangzhou Chinese.
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Chao Qiang Jiang, Bin Liu, Cheung, Bernard M. Y., Tai Hing Lam, Jie Ming Lin, Ya Li Jin, Xiao Jun Yue, Kwok Leung Ong, Tam, Sidney, Ka Sing Wong, Tomlinson, Brian, Lam, Karen S. L., and Thomas, G. Neil
- Subjects
GENETIC research ,GENETIC polymorphisms ,NUCLEOTIDES ,TRIGLYCERIDES - Abstract
Single nucleotide polymorphisms (SNPs) in the apolipoprotein A5 (APOA5) gene have been associated with hypertriglyceridaemia. We investigated which SNPs in the APOA5 gene were associated with triglyceride levels in two independent Chinese populations. In all, 1375 subjects in the Hong Kong Cardiovascular Risk Factor Prevalence Study were genotyped for five tagging SNPs chosen from HapMap. Replication was sought in 1996 subjects from the Guangzhou Biobank Cohort Study. Among the five SNPs, rs662799 (-1131T>C) was strongly related to log-transformed triglyceride levels among Hong Kong subjects (β=0.192, P=2.6 × 10
−13 ). Plasma triglyceride level was 36.1% higher in CC compared to TT genotype. This association was confirmed in Guangzhou subjects (β=0.159, P=1.3 × 10−12 ), and was significantly irrespective of sex, age group, obesity, metabolic syndrome, hypertension, diabetes, smoking and alcohol drinking. The odds ratios and 95% confidence interval for plasma triglycerides ≥1.7 mmol/l associated with TC and CC genotypes were, respectively, 1.81 (1.37-2.39) and 2.22 (1.44-3.43) in Hong Kong and 1.27 (1.05-1.54) and 1.97 (1.42-2.73) in Guangzhou. Haplotype analysis suggested the association was due to rs662799 only. The corroborative findings in two independent populations indicate that the APOA5-1131T>C polymorphism is an important and clinically relevant determinant of plasma triglyceride levels in the Chinese population. [ABSTRACT FROM AUTHOR]- Published
- 2010
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37. Coexisting Small Vessel Disease Predicts Poor Long-Term Outcome in Stroke Patients with Intracranial Large Artery Atherosclerosis.
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Jian Hui Fu, Yang Kun Chen, Xiang Yan Chen, Vincent Mok, and Ka Sing Wong
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ATHEROSCLEROSIS ,CEREBROVASCULAR disease patients ,PERIPHERAL vascular diseases ,BRAIN imaging ,MAGNETIC resonance imaging ,REGRESSION analysis ,QUANTITATIVE research ,DIAGNOSIS - Abstract
Background and Purposes: Until now, limited data are available about the potential effect of coexisting small vessel disease (SVD) on the long-term outcome of stroke patients with intracranial large artery atherosclerosis (ILAA). Methods: A prospective study was performed on 293 patients with symptomatic ILAA, who were divided into 4 groups (group I, single intracranial large artery atherosclerosis (SILAA) without SVD; group II, multiple intracranial large arteries atherosclerosis (MILAA) without SVD; group III, SILAA with SVD; group IV, MILAA with SVD) and followed up for recurrent stroke or death. Results: The 3-year cumulative risks of recurrent stroke were 18% for SILAA without SVD, 38% for MILAA without SVD, 21% for SILAA with SVD and 34% for MILAA with SVD. The 3-year cumulative risks of death were 6, 7, 20 and 22%, respectively. Compared with SILAA without SVD, more recurrent stroke occurred in MILAA without SVD (log-rank 3.83; p = 0.050) and MILAA with SVD (log-rank 7.79; p = 0.014), and the higher risk of death (log-rank 9.472; p = 0.002) was found in group MILAA with SVD. A Cox proportional-hazards regression model showed that MILAA with SVD may be a predictor of recurrent stroke (hazard ratio 2.001; 95% CI 1.108-3.934; p = 0.044), and a borderline predictor for death (hazard ratio 3.180; 95% CI 0.895-10.987; p = 0.073). Conclusion: Coexisting SVD is very common and may predict poor outcome in stroke patients with symptomatic ILAA. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2010
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38. Atherosclerotic Vascular Disease Rather than Metabolic Syndrome Predicts Ischemic Stroke in Diabetic Patients.
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Xiang Yan Chen, Thomas, G. Neil, Yang Kun Chen, Chan, Juliana C. N., and Ka Sing Wong
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ATHEROSCLEROSIS ,METABOLIC syndrome ,CEREBROVASCULAR disease ,PEOPLE with diabetes ,STENOSIS ,TRANSCRANIAL Doppler ultrasonography - Abstract
Background and Purpose: The purpose of this study was to evaluate the effect of metabolic syndrome on ischemic stroke in Chinese subjects with type 2 diabetes. Methods: Anthropometric parameters (waist circumference and body mass index), blood pressure, and plasma biochemical (lipid and glycemic profiles) were collected. Subjects with type 2 diabetes were categorized by the criteria of the updated Adult Treatment Panel III (ATP III) with the modified definitions of obesity in Asians. Transcranial Doppler was performed to define middle cerebral artery stenosis. Results: Of 2,197 patients (age 55.4 ± 11.3 years; male 40.8%; median follow-up period 8.7 years, interquartile range 7.8–9.5 years) without symptoms of cerebrovascular disease, evidence of middle cerebral artery stenosis was identified in 272 subjects (12.4%). According to NCEP ATP III criteria, 1,324 (60.3%) patients had MetS at baseline. Ischemic stroke occurred in 184 (8.4%, 184/2197) patients during follow-up. Patients with incident stroke had a higher prevalence of MetS compared with those without stroke (p = 0.004), and the number of components of MetS was also significantly increased in patients with stroke (p = 0.001). Cox regression demonstrated that MetS was not associated with incident stroke. Conclusions: In Chinese type 2 diabetic patients, metabolic syndrome does affect stroke occurrence with a higher stroke incidence among those with metabolic syndrome, but stroke occurrence seems to be better explained by other vascular risk factors than by metabolic syndrome. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2010
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39. Failure to detect association between polymorphisms of the sodium channel gene SCN1A and febrile seizures in Chinese patients with epilepsy.
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Chunbo Zhang, Virgina Wong, Ping Wing Ng, Colin Hiu Tung Lui, Ngai Chuen Sin, Ka Sing Wong, Larry Baum, and Patrick Kwan
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GENETIC polymorphisms ,EPILEPSY ,DEVELOPMENTAL disabilities ,BRAIN diseases ,PEOPLE with epilepsy ,SPASMS - Abstract
A recent study in Caucasians found an association between the single nucleotide polymorphism (SNP) of SCN1A, IVS5N +5 G>A (rs3812718), and febrile seizures (FS). We examined whether this and other tagging SNPs of SCN1A were associated with an increased risk of FS in Han Chinese. A total of 728 Han Chinese patients with focal epilepsy were recruited: 97 had a history of FS (58% male, mean age 35 ± 12 years) and 631 did not (50% male, mean age 40 ± 15 years). Genotyping was performed for IVS5N +5 G>A and seven other tagging SNPs selected from the HapMap database. Genotyping was also performed in 848 ethnically matched population controls (50% male, mean age 37 ± 17 years). There was no statistically significant difference in either allele or genotype frequency of any of the SNPs studied between epilepsy patients with and without FS, and between epilepsy patients with FS and controls. The results do not suggest that SCN1A SNPs are susceptibility factors for FS in Han Chinese. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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40. Detection of the Siphon Internal Carotid Artery Stenosis: Transcranial Doppler versus Digital Subtraction Angiography.
- Author
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Yong You, Qing Hao, Leung, Thomas, Mok, Vincent, Xiangyan Chen, Alex Lau, Howan Leung, and Ka Sing Wong
- Subjects
ARTERIAL stenosis ,CAROTID artery disease diagnosis ,TRANSCRANIAL Doppler ultrasonography ,DIGITAL subtraction angiography ,COMPARATIVE studies - Abstract
BACKGROUND Transcranial Doppler (TCD) is widely applied to evaluate the intracranial large artery stenosis. We aimed to evaluate the accuracy of TCD in detecting siphon internal carotid artery (SICA) stenosis against digital subtraction angiography (DSA). METHODS A total of 145 patients with TCD and DSA performed were recruited. The SICA and other intracranial arteries were evaluated through transorbital and transtemporal acoustic window by TCD. We defined the best cutoff value for significant SICA stenosis by receiver-operating characteristic (ROC) curve analyses and calculated the sensitivity, specificity, and positive and negative predictive values (PPV and NPV). RESULTS Mean age of the patients was 65.7 years (range 28-88 years) and 75.1% (109/145) were men. The peak systolic velocity (PSV) = 120 cm/second had the largest area under the ROC curve (area under the ROC curve = .868) compared with the MFV = 70 cm/second and MFV = 80 cm/second (area under the ROC curve = .822 and .845). So the criteria for SICA stenoses were defined as PSV = 120 cm/second plus additional parameters (abnormal spectrum, circumscribed velocity changes, or side-to-side difference). Twenty-nine patients were diagnosed with SICA stenosis or occlusion on TCD. Fourteen patients had abnormal TCD findings that were not confirmed by DSA. One patient with normal TCD but DSA showed mild (40%) stenoses. Accuracy parameters for TCD were as follows: sensitivity = 96.7% (95% confidence interval [CI]= 80.9-99.8), specificity = 93.9% (95% CI = 89.9-96.4), PPV = 65.9% (95% CI = 50.0-79.1), NPV = 99.6% (95% CI = 97.2-1.0). Most false-positive patients (11 of 15 patients) had other significant intracranial large arteries lesions. CONCLUSIONS The criteria have limited but acceptable sensitivity and specificity in detecting SICA stenoses. Abnormal findings of siphon carotid on TCD require further clarification. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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41. Effects of Statins on Progression of Subclinical Brain Infarct.
- Author
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Jian Hui Fu, Mok, Vincent, Lam, Wynnie, Wong, Adrian, Chu, Winnie, Yunyun Xiong, Ping Wing Ng, Tak Hon Tsoi, Yeung, Vincent, and Ka Sing Wong
- Subjects
STATINS (Cardiovascular agents) ,CEREBRAL infarction ,CEREBROVASCULAR disease ,DISEASE progression ,RANDOMIZED controlled trials ,STENOSIS ,MAGNETIC resonance imaging ,MULTIVARIATE analysis ,THERAPEUTICS - Abstract
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. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2010
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42. Pilot Study of New Diagnostic Criteria for Middle Cerebral Artery Stenosis by Transcranial Doppler.
- Author
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Qing Hao, Shan Gao, Thomas Wai Hong Leung, Ming Hui Guo, Yong You, and Ka Sing Wong
- Subjects
CEREBRAL arteries ,ANGIOGRAPHY ,MAGNETIC resonance ,STENOSIS ,RADIOSCOPIC diagnosis - Abstract
BACKGROUND AND PURPOSE Current criteria for middle cerebral artery (MCA) stenosis by transcranial Doppler were mainly based on the flow velocity acceleration, ignoring other useful parameters. We tested the accuracy of new criteria using magnetic resonance angiography (MRA) as the confirmative method. METHODS A compositive score for each MCA was calculated according to following parameters: Velocity Scale (score 0-6 for peak systolic velocity <140 to ≥300 cm/second), Hemodynamic Scale (score 0-5 for diffuse or focal velocity increase; score 0-6 for differences between bilateral MCA; score 17 for damping velocity), and Spectrum Scale (score 0-2 for normal spectrum, turbulence, and musical murmurs). RESULTS The median scores in normal-mild, moderate, and severe groups on MRA differed significantly ( P < .001). The optimal cutoff score for <50% and ≥50% stenosis was 3 with the PPV of 72.3% (95% confidence interval [CI]: 65.3% to 78.5%) and negative predictive value (NPV) of 89.5% (95% CI: 85.9% to 92.3%), for moderate and severe stenosis was 6 with the PPV of 85.9% (95% CI: 76.7% to 92.0%) and NPV of 61.9% (95% CI: 50.6% to 72.1%). Both scores performed better than peak systolic or mean velocity. CONCLUSIONS This new method was feasible and reliable and showed some advantages over the velocity-only method. Further studies using digital subtraction angiography as the gold standard are needed to ameliorate the new criteria. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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43. Frequency of Microemboli Signal in Stroke Patients Treated with Low Molecular Weight Heparin or Aspirin.
- Author
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Qing Hao, Hui Meng Chang, Meng Cheong Wong, Ka Sing Wong, and Christopher Chen
- Subjects
CEREBROVASCULAR disease patients ,TRANSIENT ischemic attack ,ASPIRIN ,HEPARIN ,CEREBRAL arteries - Abstract
BACKGROUND AND PURPOSE Microemboli signal (MES) detected by transcranial Doppler (TCD) may represent ongoing embolic phenomenon and is a predictor of recurrent stroke or transient ischemic attack. We sought to study the frequency of MES in stroke patients with large artery occlusive diseases treated with low molecular weight heparin (LMWH) or aspirin. METHODS Patients participating in the Fraxiparine in Ischemic Stroke (FISS)-tris study were recruited. MES detection was performed from middle cerebral artery on the 1st, 3rd, and 7th days after randomization. The correlation between the presence of MES and the treatment was determined by the χ
2 test. RESULTS Among 47 patients, 26 were randomized to LMWH and 21 to aspirin. On day 1, MES were detected in 10 patients (7/26 on LMWH, 3/21 on aspirin; P= .475). On day 3, 12 patients had MES (7/25 on LMWH, 5/20 on aspirin; P= .821). On day 7, 11 patients had MES (6/25 on LMWH, 5/20 on aspirin; P= .938). The median of the number of MES on days 1, 3, and 7 was 4 (range 1-10), 5 (range 1-42), and 3 (range 1-33) for the LMWH group and 1 (range 1-15), 4 (range 1-10), and 2 (range 1-4) for the aspirin group. CONCLUSIONS There were no significant differences in the frequency of MES between patients with large artery occlusive disease treated with LMWH and aspirin. [ABSTRACT FROM AUTHOR]- Published
- 2010
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44. Acute basal ganglia infarcts in poststroke fatigue: an MRI study.
- Author
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Wai Kwong Tang, Yang Kun Chen, Mok, Vincent, Chu, Winnie C. W., Ungvari, Gabor S., Ahuja, Anil T., and Ka Sing Wong
- Subjects
CEREBROVASCULAR disease patients ,BASAL ganglia ,INFARCTION ,FATIGUE (Physiology) - Abstract
Lesions located in the basal ganglia (BG) are thought to be involved in the fatigue observed in neurological disorders. However, the significance of the location of infarcts in poststroke fatigue (PSF) is unknown. This study examined the association between BG infarcts and PSF. A total of 334 Chinese patients with acute ischemic stroke consecutively admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. At admission, a host of demographic and clinical characteristics was collected and the number and location of acute infarcts were evaluated with MRI. All participants were assessed for PSF with the fatigue severity scale (FSS) 3 months after their index stroke. PSF was defined as a mean FSS score of 4.0 or more. Depressive symptoms were measured by the geriatric depression scale (GDS). Seventy-eight (23.4%) patients had PSF. In the univariate analysis, the PSF group included more females, had higher GDS scores, and a higher number of acute infarcts, and the PSF patients were more likely to have acute infarcts at the BG. Acute BG infarct remained an independent predictor of PSF in the multivariate analysis. In conclusion, these results suggest that BG infarcts may play a role in the development of PSF. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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45. Different Distribution Patterns of Cerebral Microbleeds in Acute Ischemic Stroke Patients with and without Hypertension.
- Author
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Jian Sun, Yannie Oi Yan Soo, Wynnie Wai Man Lam, Ka Sing Wong, Jin Sheng Zeng, and Yu Hua Fan
- Subjects
BLOOD pressure ,HYPERTENSION ,CEREBROVASCULAR disease patients ,MEDICAL care research ,CARDIOVASCULAR diseases - Abstract
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 , T2 and gradient-echo T2 *. 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. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]- Published
- 2009
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46. Statins for Asymptomatic Middle Cerebral Artery Stenosis: The Regression of Cerebral Artery Stenosis Study.
- Author
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Mok, Vincent C. T., Lam, Wynnie W. M., Chen, X. Y., Wong, Adrian, Ping Wing Ng, Tak Hon Tsoi, Yeung, Vincent, Liu, Roxanna, Yannie Soo, Leung, T. W., and Ka Sing Wong
- Subjects
STATINS (Cardiovascular agents) ,ANTICHOLESTEREMIC agents ,ENZYME inhibitors ,CAROTID artery ,ATHEROSCLEROSIS - Abstract
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. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
47. Gene-wide tagging study of association between ABCB1 polymorphisms and multidrug resistance in epilepsy in Han Chinese.
- Author
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Kwan, Patrick, Wong, Virginia, Ping Wing Ng, Colin Hiu Tung Lui, Ngai Chuen Sin, Wai Sang Poon, Ho Keung Ng, Ka Sing Wong, and Baum, Larry
- Subjects
GENETIC polymorphisms ,MULTIDRUG resistance ,EPILEPSY ,PEOPLE with epilepsy ,MESSENGER RNA ,GENE expression ,HEALTH of Chinese people - Abstract
Aims: It remains controversial whether polymorphisms of the multidrug resistance gene ABCB1 are associated with pharmacoresistance in epilepsy. To further study the potential association, we genotyped a broad set of tagging SNPs, and explored whether any associations were affected by other host factors. We correlated any association with cerebral mRNA expression of ABCB1. Materials & methods: A total of 12 tagging and candidate SNPs of ABCB1 were genotyped in 464 Chinese epilepsy patients (270 drug responsive, 194 drug resistant). Genotype and allele distributions in drug-responsive and drug-resistant patients were compared. ABCB1 mRNA was quantified by real-time PCR in brain samples resected from 20 patients with drug-resistant epilepsy. Its level was compared between patients with different genotypes of ABCB1 SNPs found to be associated with drug resistance. Results: The intronic polymorphism rs3789243 (p = 0.009 for allele analysis) and the coding polymorphism 2677G/T/A (p = 0.02), and haplotypes containing them, were associated with drug resistance. The 2677G/T/A genotypes remained significantly associated with drug resistance after multiple logistic regression and correction for multiple comparisons. The associations with drug resistance were found in males (p = 0.004 for rs3789243 and p = 0.0007 for 2677T/A>G) but not females, and in patients with localization-related (p = 0.006 for rs3789243 and p = 0.01 for 2677T/A>G) but not idiopathic-generalized epilepsy. ABCB1 mRNA levels did not correlate with genotypes. Conclusion: In Chinese epilepsy patients, the ABCB1 intronic polymorphism rs3789243 and the coding polymorphism 2677, and haplotypes containing them, may be associated with drug resistance, without an effect on mRNA expression. There was preliminary evidence of interactions between these polymorphisms and gender and epilepsy syndrome. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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48. Emotional incontinence and executive function in ischemic stroke: A case-controlled study.
- Author
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W.K. TANG, YANGKUN CHEN, WYNNIE W.M. LAM, VINCENT MOK, ADRIAN WONG, GABOR S. UNGVARI, Y.T. XIANG, and KA SING WONG
- Subjects
CEREBROVASCULAR disease ,BASAL ganglia ,PATHOLOGICAL physiology ,CEREBROVASCULAR disease patients ,FRONTAL lobe ,PSYCHOLOGY ,PHYSIOLOGY - Abstract
AbstractFrontal 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.) [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
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49. Is Counterpulsation a Potential Therapy for Ischemic Stroke?
- Author
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Jing Hao Han and Ka Sing Wong
- Subjects
MEDICAL research ,ENHANCED external counterpulsation ,CEREBRAL circulation ,CEREBROVASCULAR disease patients ,PREVENTIVE medicine - Abstract
Background: Despite the rapid progress in stroke prevention, effective acute stroke treatment except for thrombolysis is still lacking. Hypoperfusion is related to unfavorable functional outcome, further strokes and long-term mortality. Therefore, the need for a safe and effective way of increasing the cerebral blood flow seems obvious. Currently, there is a growing body of evidence to suggest that external counterpulsation (ECP) may enhance the blood supply to the brain and thus may be beneficial to patients with ischemic stroke. Methods: A MEDLINE search in combination with a search for papers in Chinese literature in the Wan Fang and China Academic Journal databases was carried out. Results: Preliminary investigations suggested that ECP may improve the clinical outcome of stroke patients. However, well-designed clinical studies exploring the therapeutic effects of ECP in ischemic stroke are very limited. Conclusions: Randomized-controlled trials with a large sample size are needed to further define the efficacy and safety of ECP in acute stroke management. Future studies should provide insight into the value of ECP in ischemic stroke as well as its possible mechanisms. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
50. Middle Cerebral Artery Stenosis Increased the Risk of Vascular Disease Mortality among Type 2 Diabetic Patients.
- Author
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Thomas, G. Neil, Xiang-Yan Chen, Jian Wen Lin, Tomlinson, Brian, Lam, Wynnie W.M., Liu, Roxanna, Yeung, Vincent T.F., Chan, Juliana C.N., and Ka Sing Wong
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MORTALITY ,DEATH (Biology) ,DIABETES ,DEATH ,DISEASES - Abstract
Background: In Chinese populations, middle cerebral artery (MCA) stenosis is the most commonly identified intracranial vascular lesion, and has been shown to be associated with an increased risk of secondary stroke mortality, but has yet to be reported for primary events. We assess whether asymptomatic MCA stenosis is associated with mortality in Chinese type 2 diabetic patients. Methods: The presence of MCA stenosis was determined by transcranial Doppler and mortality data were collated in the Hong Kong Death Registry. Cox proportional hazards regression was used to determine if the MCA stenosis (n = 272, 53.7% 2-vessel disease) in 2,197 diabetics was associated with all-cause or vascular disease mortality, including after adjustment for conventional vascular risk factors. Anthropometric and fasting biochemical parameters were compared between diabetic patients with MCA stenosis and without evidence of stenosis. Results: A total of 191 deaths were identified (30.9% of vascular disease origin) during a follow-up of 18,279 patient years over 8.32 years. After adjustment for age, gender and diabetes duration, the hazard ratios for vascular mortality for 1- and 2-vessel disease were 2.47 (95% CI = 1.13–5.38) and 4.47 (95% CI = 2.24–8.82), p < 0.001 for trend, for increasing vascular mortality with increasing severity of cerebrovascular involvement, but 0.81 (95% CI = 0.45–1.47) and 2.23 (95% CI = 1.45–1.47), p = 0.001 for trend, for all-cause mortality. For vascular mortality, further adjustments for anthropometric and fasting biochemical parameters, or existing disease and treatment history increased the hazard ratios for 1-vessel disease slightly but attenuated the risk for 2-vessel disease evidently, 2.81 (95% CI = 1.10–7.16) and 2.85 (95% = CI 1.11–7.33), p = 0.026. Conclusion: The presence of MCA stenoses was an independent predictor of vascular mortality in these diabetics. More aggressive treatment of risk factors in these subjects merits further evaluation. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
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