Biomedical subjects

David L Nyenhuis

Publications and source records attributed to David L Nyenhuis.

7 recordsLinked to original sources

PubMed2006

National Institute of Neurological Disorders and Stroke-Canadian Stroke Network vascular cognitive impairment harmonization standards.

BACKGROUND AND PURPOSE: One in 3 individuals will experience a stroke, dementia or both. Moreover, twice as many individuals will have cognitive impairment short of dementia as either stroke or dementia. The commonly used stroke scales do not measure cognition, while dementia criteria focus on the late stages of cognitive impairment, and are heavily biased toward the diagnosis of Alzheimer disease. No commonly agreed standards exist for identifying and describing individuals with cognitive impairment, particularly in the early stages, and especially with cognitive impairment related to vascular factors, or vascular cognitive impairment. METHODS: The National Institute for Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN) convened researchers in clinical diagnosis, epidemiology, neuropsychology, brain imaging, neuropathology, experimental models, biomarkers, genetics, and clinical trials to recommend minimum, common, clinical and research standards for the description and study of vascular cognitive impairment. RESULTS: The results of these discussions are reported herein. CONCLUSIONS: The development of common standards represents a first step in a process of use, validation and refinement. Using the same standards will help identify individuals in the early stages of cognitive impairment, will make studies comparable, and by integrating knowledge, will accelerate the pace of progress.

Brain↗

PubMed2006

Vascular cognitive impairment.

Vascular cognitive impairment encompasses a spectrum of clinically defined syndromes ranging from vascular cognitive impairment-no dementia, to vascular dementia. The underlying cerebrovascular pathology includes both overt infarction as well as rarefaction of gray and white matter. Alzheimer's pathology may coexist with vascular pathology. Diagnosis rests on identifying acquired cognitive impairment in the setting of documented cerebrovascular disease, based on clinical presentation and neuroimaging; MRI is more sensitive than CT. The course can be stepwise or gradually progressive. The clinical picture is typically dominated by deficits in executive function rather than the short-term memory deficit typical of Alzheimer's disease. No specific therapies exist, but treatment with anticholinesterase agents and N-methyl-d-aspartate antagonists may result in clinical improvement. Prevention remains paramount, with early recognition of populations at risk and early and aggressive management of risk factors, including hypertension, dyslipidemia, diabetes, and tobacco use as well as antithrombotic therapy, in appropriate populations.

Journal Article↗

PubMed2005

Longitudinal changes in white matter following ischemic stroke: a three-year follow-up study.

Information on longitudinal changes in white matter after stroke is limited. The aim of the present study was to quantitatively investigate longitudinal changes in the microstructural integrity of non-lesioned white matter at 1-3 years following ischemic stroke. In a sample of 80 ischemic stroke patients, we obtained diffusion tensor imaging (DTI) measures of fractional anisotropy (FA), an apparent measure of white matter integrity, in radiologically normal-appearing white matter at baseline and 3 years of follow-up. Mixed model regression analysis results showed a significant improvement in FA from baseline during the first 2 years of follow-up that stabilized by the third year of follow-up. These results demonstrate a long-term improvement in apparent white matter integrity following ischemic stroke that continues, at least, into the second year following the insult.

Aged↗

PubMed2004

The pattern of neuropsychological deficits in Vascular Cognitive Impairment-No Dementia (Vascular CIND).

We examined the pattern of neuropsychological deficits in Vascular Cognitive Impairment-No Dementia (Vascular CIND) by comparing the cognitive and behavioral performance of 41 post-stroke Vascular CIND patients to that of 62 post-stroke patients with no cognitive impairment (NCI). Neuropsychological test scores were grouped into seven cognitive and four behavioral domains, then converted to standardized, weighted principle component scores (PCS) for each domain. Multivariate logistic regression models built on cognitive domains found the immediate recall and psychomotor domains to best predict diagnostic group membership. In a separate model limited to behavioral data, the depressed mood domain best predicted group membership. The combination of immediate memory deficits, psychomotor slowness and depression have also been found in Vascular Dementia (VaD), suggesting that the pattern of deficits in Vascular CIND and VaD neuropsychological deficits are similar. This cognitive and behavioral pattern similarity supports the hypothesis that Vascular CIND lies on a continuum between NCI and VaD.

Activities of Daily Living↗

PubMed2003

The Black Seventh-Day Adventist exploratory health study.

African Americans are at high risk for stroke and dementia. Modifications of lifestyle, however, might lower this risk. The Seventh-Day Adventist (SDA) Church encourages both spiritual adherence and a healthy lifestyle. Members are encouraged to exercise and are discouraged from smoking, drinking alcoholic or caffeinated beverages, or eating meat. The present study describes an exploratory project in 2 Black SDA congregations (N = 82) designed to characterize the lifestyle, dietary, and spiritual health habits of these congregations, and to test the feasibility of collecting such information in the Black SDA community at large. Three separate data collection methods are described and evaluated. Data demonstrate that the sample differs significantly from the African-American community at large in dietary, lifestyle, and spiritual health habits. The Black SDA community represents a unique opportunity to test the effects of diet, lifestyle, and spirituality on risk for stroke and dementia.

Black or African American↗

PubMed2002

Predictors of survival in African American patients with AD, VaD, or stroke without dementia.

BACKGROUND: A hospital-based cohort of African American patients in the Chicago area with AD, vascular dementia (VaD), or stroke without dementia (SWD) were followed for up to 7 years. OBJECTIVE: To describe and analyze predictors of survival in this cohort. METHODS: Proportional hazards regression models were used to analyze risk of death in 113 patients with AD (53 deaths), 79 patients with VaD (31 deaths), and 56 patients with SWD (14 deaths). RESULTS: Patients with AD who were older and had more years of education and lower Barthel ADL scores were at higher risk of death. Patients with VaD who were taking antihypertensive medication were at higher risk of death; those who were taking aspirin or antiplatelet/anticoagulant medication were at lower risk of death; and higher diastolic blood pressure was protective against death. Risk factors for death in the SWD group were older age, having ever been a smoker, and history of atrial fibrillation. Differences in survival across the three groups were not significant after adjusting for age and clinical dementia rating. CONCLUSIONS: Results in patients with VaD support the use of antiplatelet therapy for persons with VaD and suggest that optimal blood pressure may be higher in cognitively compromised poststroke patients than persons in the general population.

Black or African American↗

PubMed2002

Cognitive and functional decline in African Americans with VaD, AD, and stroke without dementia.

OBJECTIVE: To compare the rates of cognitive and functional decline in African American patients diagnosed at baseline with vascular dementia (VaD) (n = 79), AD (n = 113), or stroke without dementia (SWD) (n = 56) and followed for up to 7 years with annual neuropsychological and other examinations. METHODS: Study patients were diagnosed using established criteria for dementia and were administered cognitive screening, functional screening, and neuropsychological measures. Baseline dementia severity was rated using the Clinical Dementia Rating Scale. Random effects modeling was used to examine rates of decline and to compare the rates of decline in the three groups. RESULTS: Both patients with VaD and those with AD showed significant cognitive and functional decline during follow-up; patients with VaD declined at a slower rate than patients with AD; and patients diagnosed with SWD at baseline did not show cognitive or functional decline during follow-up. CONCLUSIONS: Patients with VaD decline at a slower rate than patients with AD. Patients who do not meet criteria for dementia soon after stroke may not be at high risk for developing dementia. Future studies are needed to follow VaD patients with longitudinal, specialized MR protocols, concurrent neuropsychological examinations, and neuropathologic examination to determine possible neuroimaging predictors of progressive cognitive and functional decline and to assess the contribution of Alzheimer's pathology to decline in patients diagnosed with VaD.

Aged↗