Yanhong Dong

Bio: Yanhong Dong is an academic researcher from National University of Singapore. The author has contributed to research in topics: Montreal Cognitive Assessment & Dementia. The author has an hindex of 24, co-authored 69 publications receiving 1627 citations. Previous affiliations of Yanhong Dong include University Health System & University of New South Wales.

The Montreal Cognitive Assessment is superior to the Mini-Mental State Examination in detecting patients at higher risk of dementia.

Abstract: Background: To examine the discriminant validity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) in detecting patients with cognitive impairment at higher risk for dementia at a memory clinic setting. Methods: Memory clinic patients were administered the MoCA, MMSE, and a comprehensive formal neuropsychological battery. Mild cognitive impairment (MCI) subtypes were dichotomized into two groups: single domain–MCI (sd–MCI) and multiple domain-MCI (md–MCI). Area under the receiver operating characteristic curve (ROC) analysis was used to compare the discriminatory ability of the MoCA and the MMSE. Results: Two hundred thirty patients were recruited, of which 136 (59.1%) were diagnosed with dementia, 61 (26.5%) with MCI, and 33 (14.3%) with no cognitive impairment (NCI). The majority of MCI patients had md–MCI ( n = 36, 59%). The MoCA had significantly larger AUCs than the MMSE in discriminating md–MCI from the lower risk group for incident dementia (NCI and sd–MCI) [MoCA 0.92 (95% CI, 0.86–0.98) vs. MMSE 0.84 (95% CI, 0.75–0.92), p = 0.02). At their optimal cut-off points, the MoCA (19/20) remained superior to the MMSE (23/24) in detecting md–MCI [sensitivity: 0.83 vs. 0.72; specificity: 0.86 vs. 0.83; PPV: 0.79 vs. 0.72; NPV: 0.89 vs. 0.83; correctly classified: 85.1% vs. 78.7%]. Conclusion: The MoCA is superior to the MMSE in the detection of patients with cognitive impairment at higher risk for incident dementia at a memory clinic setting.

Brief screening tests during acute admission in patients with mild stroke are predictive of vascular cognitive impairment 3–6 months after stroke

Abstract: Objectives To determine the prognostic value of brief cognitive screening tests administered in the subacute stroke phase (initial 2 weeks) for the detection of significant cognitive impairment 3–6 months after stroke, the authors compared the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). Methods Patients with ischaemic stroke and transient ischaemic attack were assessed with both MoCA and MMSE within 14 days after index stroke, followed by a formal neuropsychological evaluation of seven cognitive domains 3–6 months later. Cognitive outcomes were dichotomised as either no–mild (impairment in ≤2 cognitive domains) or moderate–severe (impairment in ≥3 cognitive domains) vascular cognitive impairment. Area under the receiver operating characteristic (ROC) curve analysis was used to compare discriminatory ability. Results 300 patients were recruited, of whom 239 received formal neuropsychological assessment 3–6 months after the stroke. 60 (25%) patients had moderate–severe VCI. The overall discriminant validity for detection of moderate–severe cognitive impairment was similar for MoCA (ROC 0.85 (95% CI 0.79 to 0.90) and MMSE (ROC 0.83 (95% CI 0.77 to 0.89)), p=0.96). Both MoCA (21/22) and MMSE (25/26) had similar discriminant indices at their optimal cutoff points; sensitivity 0.88 versus 0.88; specificity 0.64 versus 0.67; 70% versus 72% correctly classified. Moreover, both tests had similar discriminant indices in detecting impaired cognitive domains. Conclusions Brief screening tests during acute admission in patients with mild stroke are predictive of significant vascular cognitive impairment 3–6 months after stroke.

Prevalence of cognitive impairment in Chinese: Epidemiology of Dementia in Singapore study

Abstract: Objective To study the prevalence of and associated factors for cognitive impairment and dementia in community dwelling Chinese from Singapore. Methods This study includes Chinese subjects from the Epidemiology of Dementia in Singapore (EDIS) study, aged ≥60 years, who underwent comprehensive examinations, including cognitive screening with the locally validated Abbreviated Mental Test and Progressive Forgetfulness Questionnaire. Screen positive participants subsequently underwent extensive neuropsychological testing and cerebral MRI. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to internationally accepted criteria. The prevalence of cognitive impairment and dementia were computed per 5 year age categories and gender. To examine the relationship between baseline associated factors and cognitive impairment, we used logistic regression models to compute odd ratios with 95% CI. Results 1538 Chinese subjects, aged ≥60 years, underwent cognitive screening: 171 (15.2%) were diagnosed with any cognitive impairment, of whom 84 were CIND mild, 80 CIND moderate and seven had dementia. The overall age adjusted prevalence of CIND mild was 7.2%; CIND moderate/dementia was 7.9%. The prevalence increased with age, from 5.9% in those aged 60–64 years to 31.3% in those aged 75–79 years and 44.1% in those aged ≥80 years. Multivariate analysis revealed age, diabetes and hyperlipidaemia to be independently associated with cognitive impairment. Conclusions In present study, the overall prevalence of cognitive impairment and dementia in Chinese was 15.2%, which is in the same range as the prevalence reported in Caucasian and other Asian populations.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Practice guideline update summary: Mild cognitive impairment: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

Abstract: Objective To update the 2001 American Academy of Neurology (AAN) guideline on mild cognitive impairment (MCI). Methods The guideline panel systematically reviewed MCI prevalence, prognosis, and treatment articles according to AAN evidence classification criteria, and based recommendations on evidence and modified Delphi consensus. Results MCI prevalence was 6.7% for ages 60–64, 8.4% for 65–69, 10.1% for 70–74, 14.8% for 75–79, and 25.2% for 80–84. Cumulative dementia incidence was 14.9% in individuals with MCI older than age 65 years followed for 2 years. No high-quality evidence exists to support pharmacologic treatments for MCI. In patients with MCI, exercise training (6 months) is likely to improve cognitive measures and cognitive training may improve cognitive measures. Major recommendations Clinicians should assess for MCI with validated tools in appropriate scenarios (Level B). Clinicians should evaluate patients with MCI for modifiable risk factors, assess for functional impairment, and assess for and treat behavioral/neuropsychiatric symptoms (Level B). Clinicians should monitor cognitive status of patients with MCI over time (Level B). Cognitively impairing medications should be discontinued where possible and behavioral symptoms treated (Level B). Clinicians may choose not to offer cholinesterase inhibitors (Level B); if offering, they must first discuss lack of evidence (Level A). Clinicians should recommend regular exercise (Level B). Clinicians may recommend cognitive training (Level C). Clinicians should discuss diagnosis, prognosis, long-term planning, and the lack of effective medicine options (Level B), and may discuss biomarker research with patients with MCI and families (Level C).