Sonny Hon - Academia.edu (original) (raw)

Papers by Sonny Hon

Research paper thumbnail of Production and Validation of Putonghua- and Cantonese-Chinese Language National Institutes of Health Stroke Scale Training and Certification Videos

International Journal of Stroke, 2010

Background and purposes The National Institutes of Health Stroke Scale (NIHSS) is an integral par... more Background and purposes The National Institutes of Health Stroke Scale (NIHSS) is an integral part of acute stroke assessment. We report our experience with new Putonghua- and Cantonese-Chinese language NIHSS (PC-NIHSS and CC-NIHSS) training and certification videos. Methods A professional video production company was hired to create the training and certification videos for both PC-NIHSS and CC-NIHSS. Two training and certification workshops were held in Chengdu and Beijing, and two workshops in Hong Kong. The instruction, training and group A certification videos were presented to workshop attendees. Unweighted κ statistics were used to measure the agreement among raters, and the inter-rater agreements for PC-NIHSS and CC-NIHSS videos were compared with those of original English language NIHSS (E-NIHSS) videos. Results The pass rates using PC-NIHSS and CC-NIHSS videos were 79% and 82%, respectively. All possible responses on individual scale items were included. Facial palsy and l...

Research paper thumbnail of Treatment received by cancer patients

<p>Treatment received by cancer patients.</p

Research paper thumbnail of Multi-variate Cox regression model of recurrent stroke in patients with and without cancer

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Research paper thumbnail of Cancer patients are at increased risk of recurrent stroke and cardiovascular mortality

Journal of the Neurological Sciences, 2013

leu) compared to patients with no CAD (p b 0.05). In MI patients APA is 1.41fold (2.92 ± 0.24 vs.... more leu) compared to patients with no CAD (p b 0.05). In MI patients APA is 1.41fold (2.92 ± 0.24 vs. 3.54 ± 0.13) higher than in patients with no MI (p b 0.05). We observed a marked increase in free radical formation on admission as demonstrated by CIIb 1.23-fold (64.75 ± 11.94 vs. 94.31 ± 10.00 mV/s * 106 leu) in patients with AF compared to patients with CA only (p b 0.05). Conclusion: In patients with CA and CVD there is an increased free radical formation even in the first 24 h, which justifies adjunctive antioxidant therapy.

Research paper thumbnail of Rapidly progressive ataxia during rehabilitation and a difficult road to diagnosis

gressed? Lessons learned from diabetes mellitus, metabolic syndrome and inflammation. J Am Geriat... more gressed? Lessons learned from diabetes mellitus, metabolic syndrome and inflammation. J Am Geriatr Soc 2013;61:845–846. 5. Viscogliosi G, Andreozzi P, Ettorre E, et al. Arterial aging impacts on the risk of late-life depressive and cognitive disorders. Is it time for prevention? Geriatr Gerontol Int 2014;14:227–228. 6. Sheline YI, Pieper CF, Barch DM et al. Support for the vascular depression hypothesis in late life depression: results from a two site prospective antidepressant treatment trial. Arch Gen Psychiatry 2010;67:277–285. 7. Pan A, Keum N, Okereke OI et al. Bidirectional association between depression and metabolic syndrome: A systematic review and meta-analysis of epidemiological studies. Diabetes Care 2012;35:1171–1180. 8. Valkanova V, Ebmeier KP. Vascular risk factors and depression in later life: A systematic review and meta-analysis. Biol Psychiatry 2013;73:406– 413. 9. Fazekas F, Chawluk JB, Alavi A et al. MR signal abnormalities at 1.5 T in Alzheimer’s dementia and normal aging. AJR Am J Roentgenol 1987;149:351–356. 10. Nasreddine ZS, Phillips NA, B edirian V et al. The Montreal Cognitive Assessment, MoCA: A brief screening tool for mild cognitive impairment. J Am Geriatr Soc 2005;53:695–699.

Research paper thumbnail of Kaplan-Meier estimate of percentage of cardiovascular mortality

<p>Kaplan-Meier estimate of percentage of cardiovascular mortality.</p

Research paper thumbnail of Multi-variate Cox regression model of cardiovascular mortality in patients with and without cancer

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Research paper thumbnail of Number of patients with fatal and non-fatal recurrent stroke

Until 2003, stroke was the third leading cause of death (after neoplasm and heart diseases) in Ho... more Until 2003, stroke was the third leading cause of death (after neoplasm and heart diseases) in Hong Kong,1 and since then it has become the fourth leading cause of death2 (pneumonia being the third). We have witnessed a secular change in stroke pattern and significant improvement in stroke case fatality rate locally in the past two decades.3-5 The proportion of ischaemic strokes increased from 62% in 1984 to 84% in 2002.3-5 The 30-day fatality rate decreased from 25% in 1989 to 11% in 2002.4,5 However, data on long-term prognosis after stroke, including mortality and recurrence, are scarce. The burden of stroke can only be meaningfully evaluated if we have reliable data on its long-term outcomes. The purpose of this study was to explore the long-term outcomes of patients with first-ever stroke.

Research paper thumbnail of Variants, Clinical Characteristics and Prognostic Factors of Guillain Barré Syndrome in Chinese (P01.135)

Neurology, 2013

OBJECTIVE: To investigate the variants, clinical characteristics and prognostic factors of Guilla... more OBJECTIVE: To investigate the variants, clinical characteristics and prognostic factors of Guillain Barre Syndrome (GBS) in Hong Kong Chinese. BACKGROUND: The variants, clinical characteristics and prognostic factors of adults with GBS in Hong Kong has not been widely studied previously. DESIGN/METHODS: We performed a retrospective review of adults with GBS admitted to Queen Mary Hospital, Hong Kong during the period 1997-2011. RESULTS: Mean age of the patients was 57+/-17 years and the mean hospital stay was 36+/-69 days. Male:female ratio was 1.5:1. Of the 63 patients with GBS, 4.8% had acute motor axonal neuropathy, 17.5% with Miller-Fisher syndrome and 77.8% were of the acute inflammatory demyelinating polyneuropathy together with other unspecified subtypes. 49.2% had preceding upper respiratory tract illness, 4.76% preceding gastrointestinal illness, whilst 7.94% received vaccination during the 6weeks preceding onset of neurological symptoms. 22.2% patients were admitted to Int...

Research paper thumbnail of Sphenopalatine Ganglion Stimulation to Augment Cerebral Blood Flow

Stroke, 2019

Background and Purpose— Many patients with acute ischemic stroke are not eligible for thrombolysi... more Background and Purpose— Many patients with acute ischemic stroke are not eligible for thrombolysis or mechanical reperfusion therapies due to contraindications, inaccessible vascular occlusions, late presentation, or large infarct core. Sphenopalatine ganglion (SPG) stimulation to enhance collateral flow and stabilize the blood-brain barrier offers an alternative, potentially more widely deliverable, therapy. Methods— In a randomized, sham-controlled, double-masked trial at 41 centers in 7 countries, patients with anterior circulation ischemic stroke not treated with reperfusion therapies within 24 hours of onset were randomly allocated to active SPG stimulation or sham control. The primary efficacy outcome was improvement beyond expectations on the modified Rankin Scale of global disability at 90 days (sliding dichotomy), assessed in the modified intention-to-treat population. The initial planned sample size was 660 patients, but the trial was stopped early when technical improveme...

Research paper thumbnail of Using the National Institutes of Health Stroke Scale

Research paper thumbnail of Cerebrovascular Disease

Medical Clinics of North America, 2009

Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors... more Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors in preparations of microvessels obtained from ipsilateral and contralateral cerebral cortices. The disruption of nerve pathways connecting the hemispheres (callosal transection) partially reverses the effect of common carotid occlusion on /3-adrenergic receptor density in capillaries of the contralateral cortex. In addition, the destruction of the central noradrenergic system by intraventricular injection of 6-hydroxydopamine abolishes the effect of ischemia on capillary ,3-adrenergic receptor function in both hemispheres. The results suggest that /3-adrenergic receptors located on microvessels are partially regulated by neuronal pathways and that focal ischemia induces neurochemical and functional changes in remote areas of the brain. Circulation 73, No. 4, 784-788, 1986. THE BRAIN is extremely sensitive to ischemia; in fact the deprivation of blood supply induces a failure in synaptic transmission and neuronal death. Both neurotransmitter function and metabolism appear altered in various cerebral areas after ischemia.1-)2 These events are accompanied by changes in microvascular functions such as increased permeability to water and decreased glucose uptake and oxygen consumption. 3-16 Recent publications have demonstrated the existence of f3-adrenergic receptors coupled to adenylate cyclase in cerebral capillaries, which seem to be involved in the regulation of microvascular function. 17-24 In a previous study we investigated the effect of common carotid occlusion on f3-adrenergic receptor function in preparations of cerebral capillaries obtained from gerbils and rats.25' 26 The results indicated a significant decrease in the number of 8-adrenergic receptors in brain microvessels of both the ipsilateral and contralateral hemispheres. Notably, in occlusion of either the right or left carotid artery the reduction in receptor density is more pronounced in the left hemisphere,

Research paper thumbnail of Beh�et's aortitis and aortic regurgitation: a report of two cases

J Am Soc Echocardiogr, 2004

Research paper thumbnail of Outcomes after first-ever stroke

Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine, 2007

To determine the outcomes after first-ever stroke, including mortality, dependence, and recurrenc... more To determine the outcomes after first-ever stroke, including mortality, dependence, and recurrence. Retrospective study on a prospectively collected cohort. Regional hospital, Hong Kong. A cohort of 755 patients presented to our hospital from 1996 to 1998 with their first-ever stroke. Mortality and stroke recurrence rate at 30 days, 1 year, and 5 years from the onset of the stroke. Dependence in activity of daily living at 5 years from the onset of stroke. The mortality rate was 15.1% at 30 days, 22.5% at 1 year, and 39.7% at 5 years from the onset of the first-ever stroke. The rate of stroke recurrence was 0.9% at 30 days, 7.0% at 1 year, and 21.2% at 5 years from the onset of first-ever stroke. Among patients presenting with ischaemic strokes, 109 (20.6%) had a recurrence, of which 92 (84%) were ischaemic strokes and 17 (16%) were haemorrhagic. Among patients presenting with intracerebral haemorrhage, 25 (23.1%) had a recurrence, of which 12 (48%) were haemorrhagic strokes and 13 ...

Research paper thumbnail of Long-term prognostic implications of visit-to-visit blood pressure variability in patients with ischemic stroke

American journal of hypertension, 2014

Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerot... more Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerotic diseases. High BPV has recently been shown to predict all-cause and cardiovascular mortality in patients with lacunar infarct. Whether BPV has prognostic implications in patients with ischemic stroke subtypes, other than those due to small-vessel occlusion, remains uncertain. We prospectively followed up the clinical outcome of 632 consecutive ischemic stroke patients without atrial fibrillation. The average BP and BPV, as determined by the coefficient of variation of the systolic and diastolic BP, were recorded during a mean 12 ± 6 outpatient clinic visits. The average age of the population was 71 ± 11 years. After a mean of 76 ± 18 months of follow-up, 161 patients died (26%); 35% (n = 56 of 161) of these deaths were due to cardiovascular causes. Sixteen percent and 5% developed recurrent stroke and acute coronary syndrome (ACS), respectively. After adjusting for mean systolic BP an...

Research paper thumbnail of Delayed recovery from ertapenem induced encephalopathy: case-report and a possible mechanism

International Journal of Clinical Pharmacy, 2013

Case The objective of this case report is to report a patient with moderate renal impairment who ... more Case The objective of this case report is to report a patient with moderate renal impairment who developed ertapenem-induced encephalopathy with delayed recovery of up to 2 weeks despite receiving and appropriately adjusted dosage of ertapenem. The patient was managed conservatively with full recovery. Carbapenem related neurotoxicity most commonly manifests as seizure with an estimated incidence of 3 %. There are increasing reports of encephalopathy being related to ertapenem and most commonly subsides within days and extended recovery of up to 2 weeks have only been reported in patients with end-stage renal failure. Conclusions Prolonged ertapenem induced encephalopathy can occur in patients with moderate renal impairment. These patients can be managed conservatively and they should make a complete recovery. Keywords Chronic kidney failure Á Delirium Á Ertapenem Impacts on practice • Equations for estimating glomerular filtration rate may not be accurate in the elderly. This may lead to unexpected side effects. • Prolonged ertapenem induced encephalopathy can occur in patients with moderate renal impairment.

Research paper thumbnail of Clinical diagnosis of patients with cerebrovascular disease

Primary Care: Clinics in Office Practice, 2004

Effective management of cerebrovascular disease patients depends on accurate diagnosis. Outpatien... more Effective management of cerebrovascular disease patients depends on accurate diagnosis. Outpatient ambulatory visits have advantages and disadvantages over inpatient encounters. In ambulatory patients, the key questions are as follows: What is the diagnosis (what and where are the vascular and brain lesions)? How urgent is the problem? Should the patient be hospitalized? What tests should be ordered, and how soon? What treatment should be prescribed? What explanations and instructions should be given? This article focuses on making the diagnosis and planning the evaluation of a patient suspected of having cerebrovascular disease.

Research paper thumbnail of Stroke Patients with a Past History of Cancer Are at Increased Risk of Recurrent Stroke and Cardiovascular Mortality

PLoS ONE, 2014

Background and Purpose: Cancer patients are at increased risk of cardiovascular and cerebrovascul... more Background and Purpose: Cancer patients are at increased risk of cardiovascular and cerebrovascular events. It is unclear whether cancer confers any additional risk for recurrent stroke or cardiovascular mortality after stroke. Methods: This was a single center, observational study of 1,105 consecutive Chinese ischemic stroke patients recruited from a large stroke rehabilitation unit based in Hong Kong. We sought to determine whether patients with cancer are at higher risk of recurrent stroke and cardiovascular mortality. Results: Amongst 1,105 patients, 58 patients (5.2%) had cancer, of whom 74% were in remission. After a mean follow-up of 76618 months, 241 patients developed a recurrent stroke: 22 in patients with cancer (38%, annual incidence 13.94%/year), substantially more than those without cancer (21%, 4.65%/year) (p,0.01). In a Cox regression model, cancer, age and atrial fibrillation were the 3 independent predictors of recurrent stroke with a hazard ratio (HR) of 2.42 (95% confidence interval (

Research paper thumbnail of Cerebrovascular Disease

Medical Clinics of North America, 2009

Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors... more Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors in preparations of microvessels obtained from ipsilateral and contralateral cerebral cortices. The disruption of nerve pathways connecting the hemispheres (callosal transection) partially reverses the effect of common carotid occlusion on /3-adrenergic receptor density in capillaries of the contralateral cortex. In addition, the destruction of the central noradrenergic system by intraventricular injection of 6-hydroxydopamine abolishes the effect of ischemia on capillary ,3-adrenergic receptor function in both hemispheres. The results suggest that /3-adrenergic receptors located on microvessels are partially regulated by neuronal pathways and that focal ischemia induces neurochemical and functional changes in remote areas of the brain. Circulation 73, No. 4, 784-788, 1986. THE BRAIN is extremely sensitive to ischemia; in fact the deprivation of blood supply induces a failure in synaptic transmission and neuronal death. Both neurotransmitter function and metabolism appear altered in various cerebral areas after ischemia.1-)2 These events are accompanied by changes in microvascular functions such as increased permeability to water and decreased glucose uptake and oxygen consumption. 3-16 Recent publications have demonstrated the existence of f3-adrenergic receptors coupled to adenylate cyclase in cerebral capillaries, which seem to be involved in the regulation of microvascular function. 17-24 In a previous study we investigated the effect of common carotid occlusion on f3-adrenergic receptor function in preparations of cerebral capillaries obtained from gerbils and rats.25' 26 The results indicated a significant decrease in the number of 8-adrenergic receptors in brain microvessels of both the ipsilateral and contralateral hemispheres. Notably, in occlusion of either the right or left carotid artery the reduction in receptor density is more pronounced in the left hemisphere,

Research paper thumbnail of FP10-MO-05 Transient global amnesia: diffusion weighted imaging findings and their implications

Journal of the Neurological Sciences, 2009

surrogate reporter for gliosis) was noninvasively and longitudinally imaged using small animal op... more surrogate reporter for gliosis) was noninvasively and longitudinally imaged using small animal optical scanner, IVIS-100 and a modified confocal scanning laser ophthalmoscope (SLO) to measure the progression of gliosis. Results: We demonstrated that the neurotoxicant-induced gliosis can be longitudinally imaged and quantified in the neonatal mouse brain and in the adult mouse retina. Using the retinal imaging platform, we have further identified a small molecular compound with neurotoxicity-suppressing and dopaminergic protecting properties in a mouse model of Parkinsonism. Conclusions: The real-time fluorescent imaging methods described here are useful pre-clinical tools for detecting neuroand retino-toxicity of various origins and for screening for potential neuroprotectants in vivo.

Research paper thumbnail of Production and Validation of Putonghua- and Cantonese-Chinese Language National Institutes of Health Stroke Scale Training and Certification Videos

International Journal of Stroke, 2010

Background and purposes The National Institutes of Health Stroke Scale (NIHSS) is an integral par... more Background and purposes The National Institutes of Health Stroke Scale (NIHSS) is an integral part of acute stroke assessment. We report our experience with new Putonghua- and Cantonese-Chinese language NIHSS (PC-NIHSS and CC-NIHSS) training and certification videos. Methods A professional video production company was hired to create the training and certification videos for both PC-NIHSS and CC-NIHSS. Two training and certification workshops were held in Chengdu and Beijing, and two workshops in Hong Kong. The instruction, training and group A certification videos were presented to workshop attendees. Unweighted κ statistics were used to measure the agreement among raters, and the inter-rater agreements for PC-NIHSS and CC-NIHSS videos were compared with those of original English language NIHSS (E-NIHSS) videos. Results The pass rates using PC-NIHSS and CC-NIHSS videos were 79% and 82%, respectively. All possible responses on individual scale items were included. Facial palsy and l...

Research paper thumbnail of Treatment received by cancer patients

<p>Treatment received by cancer patients.</p

Research paper thumbnail of Multi-variate Cox regression model of recurrent stroke in patients with and without cancer

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Research paper thumbnail of Cancer patients are at increased risk of recurrent stroke and cardiovascular mortality

Journal of the Neurological Sciences, 2013

leu) compared to patients with no CAD (p b 0.05). In MI patients APA is 1.41fold (2.92 ± 0.24 vs.... more leu) compared to patients with no CAD (p b 0.05). In MI patients APA is 1.41fold (2.92 ± 0.24 vs. 3.54 ± 0.13) higher than in patients with no MI (p b 0.05). We observed a marked increase in free radical formation on admission as demonstrated by CIIb 1.23-fold (64.75 ± 11.94 vs. 94.31 ± 10.00 mV/s * 106 leu) in patients with AF compared to patients with CA only (p b 0.05). Conclusion: In patients with CA and CVD there is an increased free radical formation even in the first 24 h, which justifies adjunctive antioxidant therapy.

Research paper thumbnail of Rapidly progressive ataxia during rehabilitation and a difficult road to diagnosis

gressed? Lessons learned from diabetes mellitus, metabolic syndrome and inflammation. J Am Geriat... more gressed? Lessons learned from diabetes mellitus, metabolic syndrome and inflammation. J Am Geriatr Soc 2013;61:845–846. 5. Viscogliosi G, Andreozzi P, Ettorre E, et al. Arterial aging impacts on the risk of late-life depressive and cognitive disorders. Is it time for prevention? Geriatr Gerontol Int 2014;14:227–228. 6. Sheline YI, Pieper CF, Barch DM et al. Support for the vascular depression hypothesis in late life depression: results from a two site prospective antidepressant treatment trial. Arch Gen Psychiatry 2010;67:277–285. 7. Pan A, Keum N, Okereke OI et al. Bidirectional association between depression and metabolic syndrome: A systematic review and meta-analysis of epidemiological studies. Diabetes Care 2012;35:1171–1180. 8. Valkanova V, Ebmeier KP. Vascular risk factors and depression in later life: A systematic review and meta-analysis. Biol Psychiatry 2013;73:406– 413. 9. Fazekas F, Chawluk JB, Alavi A et al. MR signal abnormalities at 1.5 T in Alzheimer’s dementia and normal aging. AJR Am J Roentgenol 1987;149:351–356. 10. Nasreddine ZS, Phillips NA, B edirian V et al. The Montreal Cognitive Assessment, MoCA: A brief screening tool for mild cognitive impairment. J Am Geriatr Soc 2005;53:695–699.

Research paper thumbnail of Kaplan-Meier estimate of percentage of cardiovascular mortality

<p>Kaplan-Meier estimate of percentage of cardiovascular mortality.</p

Research paper thumbnail of Multi-variate Cox regression model of cardiovascular mortality in patients with and without cancer

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Research paper thumbnail of Number of patients with fatal and non-fatal recurrent stroke

Until 2003, stroke was the third leading cause of death (after neoplasm and heart diseases) in Ho... more Until 2003, stroke was the third leading cause of death (after neoplasm and heart diseases) in Hong Kong,1 and since then it has become the fourth leading cause of death2 (pneumonia being the third). We have witnessed a secular change in stroke pattern and significant improvement in stroke case fatality rate locally in the past two decades.3-5 The proportion of ischaemic strokes increased from 62% in 1984 to 84% in 2002.3-5 The 30-day fatality rate decreased from 25% in 1989 to 11% in 2002.4,5 However, data on long-term prognosis after stroke, including mortality and recurrence, are scarce. The burden of stroke can only be meaningfully evaluated if we have reliable data on its long-term outcomes. The purpose of this study was to explore the long-term outcomes of patients with first-ever stroke.

Research paper thumbnail of Variants, Clinical Characteristics and Prognostic Factors of Guillain Barré Syndrome in Chinese (P01.135)

Neurology, 2013

OBJECTIVE: To investigate the variants, clinical characteristics and prognostic factors of Guilla... more OBJECTIVE: To investigate the variants, clinical characteristics and prognostic factors of Guillain Barre Syndrome (GBS) in Hong Kong Chinese. BACKGROUND: The variants, clinical characteristics and prognostic factors of adults with GBS in Hong Kong has not been widely studied previously. DESIGN/METHODS: We performed a retrospective review of adults with GBS admitted to Queen Mary Hospital, Hong Kong during the period 1997-2011. RESULTS: Mean age of the patients was 57+/-17 years and the mean hospital stay was 36+/-69 days. Male:female ratio was 1.5:1. Of the 63 patients with GBS, 4.8% had acute motor axonal neuropathy, 17.5% with Miller-Fisher syndrome and 77.8% were of the acute inflammatory demyelinating polyneuropathy together with other unspecified subtypes. 49.2% had preceding upper respiratory tract illness, 4.76% preceding gastrointestinal illness, whilst 7.94% received vaccination during the 6weeks preceding onset of neurological symptoms. 22.2% patients were admitted to Int...

Research paper thumbnail of Sphenopalatine Ganglion Stimulation to Augment Cerebral Blood Flow

Stroke, 2019

Background and Purpose— Many patients with acute ischemic stroke are not eligible for thrombolysi... more Background and Purpose— Many patients with acute ischemic stroke are not eligible for thrombolysis or mechanical reperfusion therapies due to contraindications, inaccessible vascular occlusions, late presentation, or large infarct core. Sphenopalatine ganglion (SPG) stimulation to enhance collateral flow and stabilize the blood-brain barrier offers an alternative, potentially more widely deliverable, therapy. Methods— In a randomized, sham-controlled, double-masked trial at 41 centers in 7 countries, patients with anterior circulation ischemic stroke not treated with reperfusion therapies within 24 hours of onset were randomly allocated to active SPG stimulation or sham control. The primary efficacy outcome was improvement beyond expectations on the modified Rankin Scale of global disability at 90 days (sliding dichotomy), assessed in the modified intention-to-treat population. The initial planned sample size was 660 patients, but the trial was stopped early when technical improveme...

Research paper thumbnail of Using the National Institutes of Health Stroke Scale

Research paper thumbnail of Cerebrovascular Disease

Medical Clinics of North America, 2009

Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors... more Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors in preparations of microvessels obtained from ipsilateral and contralateral cerebral cortices. The disruption of nerve pathways connecting the hemispheres (callosal transection) partially reverses the effect of common carotid occlusion on /3-adrenergic receptor density in capillaries of the contralateral cortex. In addition, the destruction of the central noradrenergic system by intraventricular injection of 6-hydroxydopamine abolishes the effect of ischemia on capillary ,3-adrenergic receptor function in both hemispheres. The results suggest that /3-adrenergic receptors located on microvessels are partially regulated by neuronal pathways and that focal ischemia induces neurochemical and functional changes in remote areas of the brain. Circulation 73, No. 4, 784-788, 1986. THE BRAIN is extremely sensitive to ischemia; in fact the deprivation of blood supply induces a failure in synaptic transmission and neuronal death. Both neurotransmitter function and metabolism appear altered in various cerebral areas after ischemia.1-)2 These events are accompanied by changes in microvascular functions such as increased permeability to water and decreased glucose uptake and oxygen consumption. 3-16 Recent publications have demonstrated the existence of f3-adrenergic receptors coupled to adenylate cyclase in cerebral capillaries, which seem to be involved in the regulation of microvascular function. 17-24 In a previous study we investigated the effect of common carotid occlusion on f3-adrenergic receptor function in preparations of cerebral capillaries obtained from gerbils and rats.25' 26 The results indicated a significant decrease in the number of 8-adrenergic receptors in brain microvessels of both the ipsilateral and contralateral hemispheres. Notably, in occlusion of either the right or left carotid artery the reduction in receptor density is more pronounced in the left hemisphere,

Research paper thumbnail of Beh�et's aortitis and aortic regurgitation: a report of two cases

J Am Soc Echocardiogr, 2004

Research paper thumbnail of Outcomes after first-ever stroke

Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine, 2007

To determine the outcomes after first-ever stroke, including mortality, dependence, and recurrenc... more To determine the outcomes after first-ever stroke, including mortality, dependence, and recurrence. Retrospective study on a prospectively collected cohort. Regional hospital, Hong Kong. A cohort of 755 patients presented to our hospital from 1996 to 1998 with their first-ever stroke. Mortality and stroke recurrence rate at 30 days, 1 year, and 5 years from the onset of the stroke. Dependence in activity of daily living at 5 years from the onset of stroke. The mortality rate was 15.1% at 30 days, 22.5% at 1 year, and 39.7% at 5 years from the onset of the first-ever stroke. The rate of stroke recurrence was 0.9% at 30 days, 7.0% at 1 year, and 21.2% at 5 years from the onset of first-ever stroke. Among patients presenting with ischaemic strokes, 109 (20.6%) had a recurrence, of which 92 (84%) were ischaemic strokes and 17 (16%) were haemorrhagic. Among patients presenting with intracerebral haemorrhage, 25 (23.1%) had a recurrence, of which 12 (48%) were haemorrhagic strokes and 13 ...

Research paper thumbnail of Long-term prognostic implications of visit-to-visit blood pressure variability in patients with ischemic stroke

American journal of hypertension, 2014

Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerot... more Blood pressure (BP) variability (BPV) is a novel risk factor for the development of atherosclerotic diseases. High BPV has recently been shown to predict all-cause and cardiovascular mortality in patients with lacunar infarct. Whether BPV has prognostic implications in patients with ischemic stroke subtypes, other than those due to small-vessel occlusion, remains uncertain. We prospectively followed up the clinical outcome of 632 consecutive ischemic stroke patients without atrial fibrillation. The average BP and BPV, as determined by the coefficient of variation of the systolic and diastolic BP, were recorded during a mean 12 ± 6 outpatient clinic visits. The average age of the population was 71 ± 11 years. After a mean of 76 ± 18 months of follow-up, 161 patients died (26%); 35% (n = 56 of 161) of these deaths were due to cardiovascular causes. Sixteen percent and 5% developed recurrent stroke and acute coronary syndrome (ACS), respectively. After adjusting for mean systolic BP an...

Research paper thumbnail of Delayed recovery from ertapenem induced encephalopathy: case-report and a possible mechanism

International Journal of Clinical Pharmacy, 2013

Case The objective of this case report is to report a patient with moderate renal impairment who ... more Case The objective of this case report is to report a patient with moderate renal impairment who developed ertapenem-induced encephalopathy with delayed recovery of up to 2 weeks despite receiving and appropriately adjusted dosage of ertapenem. The patient was managed conservatively with full recovery. Carbapenem related neurotoxicity most commonly manifests as seizure with an estimated incidence of 3 %. There are increasing reports of encephalopathy being related to ertapenem and most commonly subsides within days and extended recovery of up to 2 weeks have only been reported in patients with end-stage renal failure. Conclusions Prolonged ertapenem induced encephalopathy can occur in patients with moderate renal impairment. These patients can be managed conservatively and they should make a complete recovery. Keywords Chronic kidney failure Á Delirium Á Ertapenem Impacts on practice • Equations for estimating glomerular filtration rate may not be accurate in the elderly. This may lead to unexpected side effects. • Prolonged ertapenem induced encephalopathy can occur in patients with moderate renal impairment.

Research paper thumbnail of Clinical diagnosis of patients with cerebrovascular disease

Primary Care: Clinics in Office Practice, 2004

Effective management of cerebrovascular disease patients depends on accurate diagnosis. Outpatien... more Effective management of cerebrovascular disease patients depends on accurate diagnosis. Outpatient ambulatory visits have advantages and disadvantages over inpatient encounters. In ambulatory patients, the key questions are as follows: What is the diagnosis (what and where are the vascular and brain lesions)? How urgent is the problem? Should the patient be hospitalized? What tests should be ordered, and how soon? What treatment should be prescribed? What explanations and instructions should be given? This article focuses on making the diagnosis and planning the evaluation of a patient suspected of having cerebrovascular disease.

Research paper thumbnail of Stroke Patients with a Past History of Cancer Are at Increased Risk of Recurrent Stroke and Cardiovascular Mortality

PLoS ONE, 2014

Background and Purpose: Cancer patients are at increased risk of cardiovascular and cerebrovascul... more Background and Purpose: Cancer patients are at increased risk of cardiovascular and cerebrovascular events. It is unclear whether cancer confers any additional risk for recurrent stroke or cardiovascular mortality after stroke. Methods: This was a single center, observational study of 1,105 consecutive Chinese ischemic stroke patients recruited from a large stroke rehabilitation unit based in Hong Kong. We sought to determine whether patients with cancer are at higher risk of recurrent stroke and cardiovascular mortality. Results: Amongst 1,105 patients, 58 patients (5.2%) had cancer, of whom 74% were in remission. After a mean follow-up of 76618 months, 241 patients developed a recurrent stroke: 22 in patients with cancer (38%, annual incidence 13.94%/year), substantially more than those without cancer (21%, 4.65%/year) (p,0.01). In a Cox regression model, cancer, age and atrial fibrillation were the 3 independent predictors of recurrent stroke with a hazard ratio (HR) of 2.42 (95% confidence interval (

Research paper thumbnail of Cerebrovascular Disease

Medical Clinics of North America, 2009

Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors... more Common carotid occlusion in the rat significantly decreases the density of ,-adrenergic receptors in preparations of microvessels obtained from ipsilateral and contralateral cerebral cortices. The disruption of nerve pathways connecting the hemispheres (callosal transection) partially reverses the effect of common carotid occlusion on /3-adrenergic receptor density in capillaries of the contralateral cortex. In addition, the destruction of the central noradrenergic system by intraventricular injection of 6-hydroxydopamine abolishes the effect of ischemia on capillary ,3-adrenergic receptor function in both hemispheres. The results suggest that /3-adrenergic receptors located on microvessels are partially regulated by neuronal pathways and that focal ischemia induces neurochemical and functional changes in remote areas of the brain. Circulation 73, No. 4, 784-788, 1986. THE BRAIN is extremely sensitive to ischemia; in fact the deprivation of blood supply induces a failure in synaptic transmission and neuronal death. Both neurotransmitter function and metabolism appear altered in various cerebral areas after ischemia.1-)2 These events are accompanied by changes in microvascular functions such as increased permeability to water and decreased glucose uptake and oxygen consumption. 3-16 Recent publications have demonstrated the existence of f3-adrenergic receptors coupled to adenylate cyclase in cerebral capillaries, which seem to be involved in the regulation of microvascular function. 17-24 In a previous study we investigated the effect of common carotid occlusion on f3-adrenergic receptor function in preparations of cerebral capillaries obtained from gerbils and rats.25' 26 The results indicated a significant decrease in the number of 8-adrenergic receptors in brain microvessels of both the ipsilateral and contralateral hemispheres. Notably, in occlusion of either the right or left carotid artery the reduction in receptor density is more pronounced in the left hemisphere,

Research paper thumbnail of FP10-MO-05 Transient global amnesia: diffusion weighted imaging findings and their implications

Journal of the Neurological Sciences, 2009

surrogate reporter for gliosis) was noninvasively and longitudinally imaged using small animal op... more surrogate reporter for gliosis) was noninvasively and longitudinally imaged using small animal optical scanner, IVIS-100 and a modified confocal scanning laser ophthalmoscope (SLO) to measure the progression of gliosis. Results: We demonstrated that the neurotoxicant-induced gliosis can be longitudinally imaged and quantified in the neonatal mouse brain and in the adult mouse retina. Using the retinal imaging platform, we have further identified a small molecular compound with neurotoxicity-suppressing and dopaminergic protecting properties in a mouse model of Parkinsonism. Conclusions: The real-time fluorescent imaging methods described here are useful pre-clinical tools for detecting neuroand retino-toxicity of various origins and for screening for potential neuroprotectants in vivo.