[Show abstract][Hide abstract] ABSTRACT: Intracranial large artery disease (ICLAD) is a major cause of ischemic stroke. Retinal microvascular changes are associated with stroke, including small vessel cerebral disease and extracranial carotid disease. We examined the relationship between ICLAD and retinal microvascular changes.
This is a prospective cohort of 802 acute ischemic stroke patients. Retinal changes were assessed from photographs by graders masked to clinical data. ICLAD was evaluated using prespecified criteria.
ICLAD was not associated with ipsilateral retinal arteriolar/venular caliber, focal arteriolar narrowing, or arteriovenous nicking. Severe enhanced arteriolar light reflex was independently associated with any ICLAD (P=0.006) and severe ICLAD (P<0.001).
Enhanced arteriolar light reflex, but not retinal vessel caliber, was related to ICLAD. These data suggest that retinal microvascular signs have specific associations with large cerebral vessel disease.
[Show abstract][Hide abstract] ABSTRACT: Family history is a known non-modifiable risk factor of stroke. We aimed to compare the frequency of a family history of vascular disease between ethnic South Asian and Chinese stroke patients. We studied consecutive ethnic South Asian and Chinese ischaemic stroke patients matched for age, gender and presence of diabetes. Among the 152 matched pairs, ethnic South Asian ischaemic stroke patients had a higher frequency of vascular family history (IHD OR 3.465 p<0.001; CVD OR 1.754 p=0.059; and either IHD or CVD OR 2.169 p=0.003) compared to matched ethnic Chinese patients, independent of past IHD history and stroke subtype. In the ethnic South Asian cohort, patients < or = 60 years old had a higher frequency of a family history of IHD (37% vs 13%, p<0.001), CVD (34% vs 15%, p=0.005) and either IHD or CVD (52% vs 25%, p<0.001) compared to those >60 years. Family history of vascular disease is common among ethnic South Asian ischaemic stroke patients, particularly among those < or = 60 years old. We postulate that the higher frequency of a vascular family history among ethnic South Asians compared to ethnic Chinese may be explained by genetic, environmental and lifestyle influences, or interactions between these factors.
Journal of the neurological sciences 07/2009; 285(1-2):118-20. · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: Intracranial large artery disease (ICLAD) is a common stroke subtype that carries a poor prognosis. We studied the association of arterial stiffness, a recognized risk factor for atherosclerosis and ICLAD among ethnic Chinese and South Asian ischemic stroke patients.
Methods: In this prospective study, we recruited consecutive ischemic stroke patients of Chinese and South Asian ethnicity. ICLAD was assessed by transcranial color-coded Doppler or magnetic resonance angiographic studies. Arterial stiffness was measured by carotid-femoral pulse wave velocity (cPWV).
Results: Among the 268 patients studied, the prevalence of ICLAD was 54% and median cPWV was 11.4 m/s (interquartile range 9.0-13.6 m/s). Patients with ICLAD had higher cPWV compared with those without (median 11.7 vs. 11.0 m/s, P = 0.015). In multivariate analysis, patients with ICLAD were significantly more likely to have cPWV measurements in the highest quintile (>14.1 m/s) compared with patients without ICLAD independently of other covariates [odds ratio 2.21, P = 0.038].
Conclusion: This study revealed a novel association between arterial stiffness and ICLAD among ischemic stroke patients. The findings suggest that arterial stiffness may be involved in the pathophysiology of ICLAD. Future studies should investigate the effects of reducing arterial stiffness among stroke patients with ICLAD.
Journal of Hypertension 06/2009; 27(7):1453-1458. · 4.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The association of metabolic syndrome (MetS) and intracranial large artery disease (ICLAD) has been described, but only in cohorts of ethnic Korean patients with stroke. We investigated the relationship of MetS and ICLAD among ethnic Chinese patients.
This is a prospective study of consecutive ethnic Chinese patients with acute ischemic stroke living in Singapore. ICLAD was diagnosed on transcranial color-coded Doppler or magnetic resonance angiography.
Among the 135 patients studied, the frequency of MetS was higher among patients with ICLAD (39% v 16%, P = .003). This association was independent of age, hypertension, and diabetes (P = .003), and individual MetS criteria (P = .004). The prevalence of ICLAD positively correlated with the number of MetS criteria fulfilled (P = .021).
Our findings of an association between MetS and ICLAD among ethnic Chinese patients with stroke concur with findings among ethnic Korean patients. This validation provides a basis for further investigation into the pathophysiologic link between MetS and ICLAD.
Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 01/2009; 18(6):424-7.
[Show abstract][Hide abstract] ABSTRACT: Inflammation, a vascular risk factor, is more pronounced among ethnic South Asians compared to ethnic Chinese in the general population. We compared serum erythrocyte sedimentation rate (ESR) levels between ethnic South Asian and Chinese acute ischemic stroke patients, and further investigated if metabolic syndrome or central obesity could account for any difference detected. We prospectively recruited consecutive ischemic stroke patients within seven days of onset. Measurement of serum ESR was performed within two days of admission. Median serum ESR was higher among the 55 ethnic South Asian (16 mm/h IQR 3-35) compared to the 165 ethnic Chinese patients (9 mm/h IQR 4-19), p=0.004). Serum ESR was correlated with age. Higher serum ESR was associated with female gender, non-smokers, patients with central obesity and low high-density lipoprotein (HDL) cholesterol. Using regression analysis, South Asian ethnicity remained significantly associated with serum ESR, independent of age, gender, smoking status, metabolic syndrome, central obesity and low HDL. Ethnic South Asian ischemic stroke patients have a higher inflammatory state compared to ethnic Chinese patients. As the higher inflammatory state is independent of demographic and risk factors, we propose an underlying genetic or cultural basis for the ethnic difference.
Journal of the Neurological Sciences 11/2008; 276(1-2):126-9. · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients with ischemic stroke have a high prevalence of hypertension and diabetes, which are major risk factors for potentially blinding retinal diseases. We studied the prevalence of retinal diseases, and the need for an ophthalmology referral, among persons with acute ischemic stroke.
We conducted a prospective study of 300 consecutive patients with acute ischemic stroke. Retinal photographs were taken and assessed in a masked fashion. Patients were advised and referred if they required an ophthalmology evaluation.
Of the 286 patients with gradable photographs, retinal abnormalities were detected in 59%. Ophthalmology evaluation was advised for 3% of patients on an urgent basis and 28% on a nonurgent basis and resulted in either acute treatment or active follow-up for all who were subsequently reviewed.
Patients with acute ischemic stroke have a high prevalence of retinal abnormalities. This study suggests that a routine retinal examination may provide an opportunity to detect potentially vision-threatening retinal diseases.
[Show abstract][Hide abstract] ABSTRACT: South Asians are the most prevalent ethnic group in the world. Intracranial disease is the most common vascular lesion worldwide.
We prospectively studied 200 consecutive ethnic South Asian patients with acute ischemic stroke in Singapore.
Intracranial large-artery disease was prevalent among 54% of all stroke subtypes and was independently associated with hypertension and higher serum erythrocyte sedimentation rate.
Among ethnic South Asian patients with ischemic stroke, intracranial large arteries are the predominant site of disease.
[Show abstract][Hide abstract] ABSTRACT: Pathogenic PINK1 mutations have been described in PARK6-linked Parkinson's disease (PD) patients of Asian origin. However, data on the frequency of PINK1 mutations in sporadic early-onset Parkinson's disease (EOPD) Asian patients are lacking. The objectives of this study were to report the frequency of PINK1 mutations of sporadic EOPD in an Asian cohort comprising of ethnic Chinese, Malays, and Indians, and to highlight a PINK1-positive patient who presented with restless legs symptoms. Eighty consecutive sporadic EOPD patients from the movement disorder clinics of two major tertiary institutions in the country were included. We performed sequence analysis of all the coding and exon-intron junctions of the PINK1 using specific primer sets. In addition, we genotyped polymorphisms detected from the analysis in a group of sporadic PD patients and controls. Three different mutations (two homozygous nonsense and one heterozygous missense) in the putative kinase domain were found in three patients, giving a 3.7% frequency of PINK1 mutations in our EOPD cohort. All the mutations were absent in 200 healthy controls. One patient with a novel homozygous nonsense PINK1 mutation presented unusually with restless legs symptoms. Separately, analysis of the frequency of four PINK1 polymorphisms in a group of sporadic PD and controls did not reveal any significant differences. We highlight a 3.7% frequency of PINK1 mutations in an Asian cohort (ethnic Chinese, Malay, and Indian) of EOPD. The phenotypic spectrum associated with PINK1-positive patients may be wider than previously reported. Polymorphisms of PINK1 do not appear to modulate risk of PD in our population.
Movement Disorders 07/2006; 21(6):789-93. · 4.56 Impact Factor