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N Venketasubramanian

Publications and source records attributed to N Venketasubramanian.

At least 19 recordsLinked to original sources
PubMed2006

Incidence of Parkinson's disease in Singapore.

To investigate the incidence of Parkinson's disease (PD) in Singapore, a parkinsonism-free cohort of 14,835 participants was followed-up and incident cases of PD identified through phone interviews, medical record reviews and a hospital's database. A movement disorders specialist subsequently verified the diagnosis through a medical records review. The age and sex-adjusted (US 1990 population) incidence rate was 32 per 100,000 person years for individuals aged 50 years and above. The rates differed between Chinese, Malays and Indians (p=0.03). The difference in inter-racial rates needs to be interpreted with caution in view of the small numbers. The incidence of PD in Singapore is comparable with that in Western countries.

Age Distribution↗
PubMed2006

Screening for dementia in the older Chinese with a single question test on progressive forgetfulness.

OBJECTIVES: To assess the utility of asking for presence of progressive forgetfulness (PF) prior to administering the Abbreviated Mental Test (AMT) when screening for dementia in the community-dwelling elderly Chinese. METHODS: This was a two-phased community-based survey of elderly subjects (>or=50 yrs). In phase one, subjects were asked for PF and administered the AMT. Those having PF or an impaired AMT performance were evaluated clinically for dementia in phase two, which also included a randomly selected sample of 35 subjects with no PF and who passed the AMT. RESULTS: 2,566 subjects completed phase one interview, of which 128 subjects completed phase two. Overall prevalence of PF, failed AMT and dementia were 2.4%, 2.2%, 0.9% respectively. The sensitivity of PF for dementia was 95.7% with specificity of 45.1%. PF was significantly associated with depression in the young-old (50-74 yrs) but not in the old-old (>or=75 yrs) age group, after adjusting for dementia. The probability of subjects (%) in the four possible diagnostic combinations of PF and AMT in the young-old and (old-old) age groups were 0 (0.06) in the no PF/ passed AMT, 0 (0.44) in the no PF/failed AMT, 0.23 (9.2) in the PF/passed AMT and 3.6 (43) in the PF/failed AMT groups. CONCLUSION: In screening for the most common dementias, AMT administration is not required if PF is absent. AMT is also of no added utility for diagnosing dementia in older subjects with PF. Younger subjects with PF should be closely evaluated for depression especially if they passed the AMT, and dementia, if they failed the AMT.

Age Factors↗
PubMed2005

Prevalence of essential tremor in Singapore: a study on three races in an Asian country.

To investigate the prevalence of Essential Tremor (ET) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians, a community-based survey among a disproportionate random sample of 15,000 individuals (9000 Chinese, 3000 Malays, 3000 Indians) aged 50 years and above was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a screening questionnaire for Parkinson's disease. In phase 2, medical specialists examined participants who screened positive to evaluate for the presence of postural or kinetic tremor of the upper limbs, or head tremor. Participants with suspected ET had their diagnosis confirmed in phase 3 by a movement disorders specialist and fellow based on the latest core diagnostic criteria. Forty participants with classic ET were identified. The prevalence rate (PR) of ET was 2.37 per 1000 (95% CI: 1.65-3.32), age-adjusted to UICC world standard population. The PR was significantly higher in males (p=0.01) and increased significantly with age (p<0.001). Indians (PR=4.94 per 1000, 95% CI: 2.63-9.04) were 1.8 times more likely to have ET than Chinese (PR=2.77 per 1000, 95% CI: 1.78-4.17) (p=0.08). No Malays with ET were identified. The data suggest that the prevalence of ET increases with age, is higher in males and may be higher amongst Indians.

Age Distribution↗
PubMed2004

Prevalence of Parkinson disease in Singapore: Chinese vs Malays vs Indians.

OBJECTIVE: To investigate the prevalence of Parkinson disease (PD) in Singapore and compare the rates between Singaporean Chinese, Malays, and Indians. METHODS: A three-phase community-based survey among a disproportionate random sample of 15,000 individuals (9,000 Chinese, 3,000 Malays, 3,000 Indians) aged 50 years and above who live in central Singapore was conducted. In phase 1, trained interviewers conducted a door-to-door survey using a validated 10-question questionnaire. In phase 2, medical specialists examined participants who screened positive to any of the questions. Participants suspected to have PD had their diagnosis confirmed in phase 3 by a movement disorders specialist. RESULTS: The participation rate was 67% among 22,279 eligible individuals. Forty-six participants with PD were identified of which 16 were newly diagnosed cases. The prevalence rate of PD for those aged 50 and above in Singapore was 0.30% (95% CI: 0.22 to 0.41), age-adjusted to US 1970 census. The prevalence rates increased significantly with age. The age-adjusted prevalence rates among Chinese (0.33%, 95% CI: 0.22 to 0.48), Malays (0.29%, 95% CI: 0.13 to 0.67), and Indians (0.28%, 95% CI: 0.12 to 0.67) were the same (p = 1.0). CONCLUSIONS: The prevalence of PD in Singapore was comparable to that of Western countries. Race-specific rates were also similar to previously reported rates and similar among the three races. Environmental factors may be more important than racially determined genetic factors in the development of PD.

Aged↗
PubMed2004

Large artery ischaemic stroke in severe acute respiratory syndrome (SARS).

Of the 206 patients who contracted Severe Acute Respiratory Syndrome (SARS) in Singapore five developed large artery cerebral infarctions. Four patients were critically-ill and three died. Intravenous immunoglobulin was given to three patients. An increased incidence of deep venous thrombosis and pulmonary embolism was also observed among the critically-ill patients. We believe our experience warrants an increased vigilance against stroke and other thrombotic complications among critically-ill SARS patients in future outbreaks, especially if treatment such as intravenous immunoglobulin, that increases pro-thrombotic tendency, is contemplated.

Adult↗
PubMed2004

Combined diffusion-weighted and spectroscopic MR imaging in Creutzfeldt-Jakob disease.

A 49-year-old woman presented with progressive dementia. Diffusion-weighted MR images showed abnormalities in the cerebral cortex as well as the putamen and caudate head bilaterally. MR spectroscopic imaging revealed marked asymmetric decrease of normal metabolites in the right basal ganglia, with concordant hypoperfusion on single photon emission computed tomography. Diffusion-weighted MR imaging is more sensitive to cortical involvement in sporadic Creutzfeldt-Jakob Disease, and MR spectroscopy may yield evidence of asymmetric involvement. Combined functional and metabolic MR imaging may be useful in studying CJD.

Brain↗
PubMed2002

A case of Sjögren's syndrome or multiple sclerosis? A diagnostic and therapeutic dilemma.

BACKGROUND: Primary Sjögren's syndrome (SS) with central nervous system involvement and antiphospholipid syndrome have been reported to mimic multiple sclerosis (MS). SS has also been found in patients diagnosed with definite MS. PATIENTS AND METHODS: A Chinese lady developed multiple relapsing neurological events involving the brain and spinal cord from the age of 40 years. Magnetic resonance imaging of the brain and spinal cord during acute relapses showed increased T2 signals and spinal cord edema. She later developed positive anti-nuclear antibody and anti-Ro autoantibody followed by sicca symptoms, confirming the diagnosis of SS. She died from aspiration pneumonia following pseudobulbar palsy shortly after SS was diagnosed. CONCLUSIONS: Patients with MS-like disease and autoantibodies should be carefully evaluated for other systemic autoimmune diseases as the treatment and prognosis differ from MS. In particular, sicca symptoms should be sought as they often go unnoticed by patients. This is especially important in Orientals in whom MS is relatively uncommon.

Adult↗
PubMed2002

Hyperhomocyst(e)inemia and risk of ischemic stroke among young Asian adults.

BACKGROUND AND PURPOSE: Hyperhomocyst(e)inemia is emerging as a possible risk factor for stroke, possibly because of accelerated atherosclerosis. There are no previous publications evaluating homocyst(e)ine in young Asian ischemic stroke patients. We conducted a case-control study examining homocyst(e)ine, vitamin B12, and folate levels in young, first-ever Asian ischemic stroke patients. METHODS: We prospectively recruited 109 consecutive young (<50 years) first-ever hospitalized ischemic stroke patients and 88 age/gender-matched hospital-based controls during a period of 18 months. Prevalence of vascular risk factors was assessed; fasting homocyst(e)ine, vitamin B12, and folate were assayed. Stroke mechanisms were subtyped using TOAST study criteria. RESULTS: Mean age was 43.8 (cases) and 43.1 (controls) years; 71.6% were male (cases and controls). Diabetes mellitus, hypertension, and hyperlipidemia were significantly more prevalent in cases. Mean fasting homocyst(e)ine levels were significantly higher in cases (13.7 micro mol/L, 95% CI: 12.7 to 14.9) than controls (10.8 micro mol/L, 95% CI: 9.9 to 11.8, P<0.001). Mean vitamin B12 levels were significantly lower in cases (299.5 pmol/L, 95% CI: 266.7 to 332.3) than controls (394.5 pmol/L, 95% CI: 357.9 to 431.0, P<0.001). Folate levels were not significantly different. Mean homocyst(e)ine levels were significantly elevated in large-artery strokes (16.9 micro mol/L, 95% CI: 14.5 to 19.7, P<0.001) but not other stroke subtypes compared with controls. Compared with the lowest homocyst(e)ine quartile, the highest quartile was significantly associated with an adjusted odds ratio of 4.3 for ischemic stroke and 25.3 for large-artery stroke. Using a logistic regression model, the adjusted odds ratio was 5.17 (95% CI: 1.96 to 13.63, P=0.001) for every 1 micro mol/L increase in log homocyst(e)ine. CONCLUSIONS: Hyperhomocyst(e)inemia is an independent risk factor for ischemic strokes in young Asian adults. The relationship between increasing homocyst(e)ine and stroke risk is strong, graded, and significant. The association with large-artery strokes suggests that hyperhomocyst(e)inemia may increase stroke risk via a proatherogenic effect.

Adolescent↗
PubMed2002

Stroke disease management--a framework for comprehensive stroke care.

Disease management is an approach to patient care that coordinates medical resources for the patient across the entire healthcare delivery system throughout the lifetime of the patient with the disease. Stroke is suitable for disease management as it is a well-known disease with a high prevalence, high cost, variable practice pattern, poor clinical outcome, and managed by a non-integrated healthcare system. It has measurable and actionable outcomes, with available local expertise and support of the Ministry of Health. Developing the programme requires a multidisciplinary team, baseline data on target populations and healthcare services, identification of core components, collaboration with key stakeholders, development of evidence-based clinical practice guidelines and carepaths, institution of care coordinators, use of information technology and continuous quality improvement to produce an effective plan. Core components include public education, risk factor screening and management, primary care and specialist clinics, acute stroke units, inpatient and outpatient rehabilitation facilities, and supportive community services including medical, nursing, therapy, home help and support groups for patients and carers. The family physician plays a key role. Coordination of services is best done by a network of hospital and community-based care managers, and is enhanced by a coordinating call centre. Continuous quality improvement is required, with audit of processes and outcomes, facilitated by a disease registry. Pitfalls include inappropriate exclusion of deserving patients, misuse, loss of physician and patient independence, over-estimation of benefits, and care fragmentation. Collaboration and cooperative among all parties will help ensure a successful and sustainable programme.

Comprehensive Health Care↗
PubMed2002

Update in the management of stroke.

Recent advances have improved the outlook for patients with stroke, Singapore's fourth leading cause of death. Stroke unit care reduces death, dependency and institutionalisation, independent of age, gender and stroke severity. Neuroimaging is essential prior to initiation of specific therapies. While computed tomography (CT) Head remains the most widely used modality, magnetic resonance imaging (MRI), particularly diffusion weighted imaging (DWI) has enhanced the positive diagnosis of ischaemic stroke. General medical measures include close monitoring, adequate oxygenation, avoidance of excessive blood pressure lowering, reduction of hyperthermia, control of hyperglycaemia, adequate nutrition, prevention of complications and early rehabilitation. Despite the risk of fatal intracranial haemorrhage, thrombolysis may improve outcomes in appropriately selected patients with ischaemic stroke. No safe and effective neuroprotectant has been found. While suboccipital craniectomy is established for large cerebellar infarcts and haemorrhage, surgical evacuation of supratentorial haemorrhage has not been shown to be beneficial. Hemicraniectomy reduces mortality after massive hemispheric ischemic stroke. Early and sustained antiplatelet use after atherothrombotic stroke reduces stroke recurrence. Stroke recurrence is also reduced by sustained warfarin use for cardioembolic stroke, carotid endarterectomy for severe symptomatic internal carotid artery stenosis, blood pressure lowering starting after the acute phase of stroke and lipid lowering. On-going clinical trails are likely to provide better treatments in the near future.

Aged↗
PubMed2001

Accuracy of bedside clinical methods compared with fiberoptic endoscopic examination of swallowing (FEES) in determining the risk of aspiration in acute stroke patients.

This prospective study was undertaken to determine the accuracy of bedside clinical methods compared with fiberoptic endoscopic examination of swallowing (FEES) for detecting aspiration in acute stroke patients. Fifty patients underwent an examination of their ability to swallow 50 ml of water in 10-ml aliquots. Later their oxygen saturation levels before and after swallowing 10 ml of water were measured using a pulse oximeter. Oxygen desaturation of more than 2%, was considered to be clinically significant. All patients then underwent a FEES assessment by a speech therapist and were followed up during their inpatient stay for evidence of aspiration pneumonia. The oxygen desaturation test had a sensitivity of 76.9% and specificity of 83.3% (chi2 = 18.154, p = 0.00002), while the 50-ml water swallow test had a sensitivity of 84.6% and specificity of 75.0% (chi2 = 18.001, p = 0.00002). However, when these two tests were combined into one test called "bedside aspiration," the sensitivity rose to 100% with a specificity of 70.8% (chi2 = 27.9, p = 0.000001). Five (10%) patients developed pneumonia during their inpatient stay. The relative risk (RR) of developing pneumonia, if there was evidence of aspiration on FEES, was 1.24 (1.03 < RR < 1.49). We conclude that the oxygen desaturation test combined with the 50-ml water swallow test is suitable as a screening test to identify all acute stroke patients at risk of aspiration for further evaluation and management.

Acute Disease↗
PubMed2001

Hypertensive basal ganglia hemorrhage: a prospective study comparing surgical and nonsurgical management.

BACKGROUND: The optimal treatment of hypertensive supratentorial intracerebral hemorrhage is still debated. Some studies have shown no improvement in survival or functional outcome after surgery when compared to conservative management while others have shown otherwise. METHODS: This study was a prospective trial, matching patients for hematoma volume and Glasgow Coma score on admission. RESULTS: There were a total of 34 patients. Seventeen were treated conservatively and 17 surgically. There was no significant difference between the two groups in terms of age, GCS, hematoma volume, or presence of intraventricular blood. At 3, 6, and 12-month follow-up, they were assessed using the Modified Barthel Index by a blinded observer. There was no difference between the two groups at 3, 6, or 12 months follow-up. The mortality rate was similar in the two groups. CONCLUSIONS: Based on this study and review of the literature, we cannot recommend routine evacuation of clots to treat these hemorrhages.

Adult↗
PubMed2001

Heparin induced thrombocytopenia.

BACKGROUND: Heparin is a widely used antithrombotic agent for treatment of ischemic cerebrovascular disease. One of its most important side-effects is thrombocytopenia which may lead to potentially life-threatening haemorrhagic and thrombotic complications. METHODS: We performed a prospective study to determine the frequency of heparin induced thrombocytopenia. Heparin induced thrombocytopenia is defined as a platelet count of less than 150 x 10(3)/mm3 or a decrease in platelet count to 30% to 50% from baseline. Daily platelet counts were obtained in 50 adult patients who were treated with the same lot of intravenous bovine heparin. Two patients (4%) developed thrombocytopenia with onset varying from four to seven days after heparin was started. In both cases, platelet counts returned to baseline levels three to five days after cessation of therapy. No ischemic or haemorrhagic complications occurred. CONCLUSION: Heparin induced thrombocytopenia is a common complication of intravenous heparin treatment. Clinicians treating patients with heparin should determine platelet counts at baseline and henceforth at regular intervals beginning from the fifth day of therapy. We recommend commencement of warfarin therapy concurrently with heparin infusion and discontinuation of heparin once warfarin has become effective. All doctors must be vigilant to this reversible common complication.

Adult↗
PubMed2001

Stroke pathways.

Stroke pathways are task-orientated structured multidisciplinary care plans which detail essential steps and interventions during the period of care of a "typical" stroke patient. Pathway development and implementation are best achieved by an appointed champion leading a multidisciplinary team of health care workers and administrators, who will also be the end users of the pathway. Pathway development involves reviews of existing clinical practice guidelines and pathways, followed by documentation, interdigitation and prioritization of care requirements at different time points in the various spheres, taking into consideration local philosophies and practices. These spheres could include investigations, pharmacologic treatment, rehabilitative therapy, nursing measures, and patient education. This would result in evidence-based holistic quality care, wide support base, efficient service provision, reduced costs and length of stay, less practice variation, improved communication among disciplines, enhanced patient-staff relationship, ease of audit and research opportunities. Components of the pathway could include a patient summary sheet, multidisciplinary record of the various activities structured on a day-to-day basis, sign-off columns for staff responsible for performing those activity, variance sheet, and separate protocols for specific issues. Implementation requires training of users, pilot runs, feedback, regular revisions, monitoring of compliance, and analysis of variances. Widespread implementation of pathways may be hindered by lack of support, and concerns about increased time requirements and costs, stifling of innovation, restriction of application of clinical judgement, lack of applicability to all patients, misuse and legal issues. However, a well-designed pathway will ensure quality care in a cost-efficient manner, benefiting the patient, carer and the health care service.

Critical Pathways↗
PubMed2000

Elimination of phenytoin in toxic overdose.

Phenytoin is widely used for the management of seizures. Fortunately overdosage with this drug is rare. We performed a prospective study to investigate the elimination kinetics of phenytoin in toxic overdose. All patients were only on phenytoin and not on other anticonvulsants. Phenytoin toxicity was defined by clinical features and correlated with drug levels. Daily phenytoin levels were obtained until they were less than or equal to 15 mcg/ml. Nine patients with age ranging from 20 to 66-years-old were recruited. Sex ratio was male:female, 5:4. Initial phenytoin levels ranged from 34 to 57.5 mcg/ml. Serum phenytoin levels of three patients remained relatively constant for 2-5 days before declining in a steady fashion. Phenytoin levels of the remaining patients declined in an almost linear manner. Regression analysis of all patients showed that the slope terms were highly significant (with low P-values) and corresponding R(2) values were close to 1. Different patients have different rates of metabolism; in seven of nine patients, levels declined between 4.6 and 5.9 mcg/ml per day. Knowledge of the rate of elimination assists the clinician in deciding on the best time to reinstitute phenytoin therapy.

Adult↗