American and Canadian health agencies convened an expert panel to begin filling an important diagnostic gap – the lack of widely accepted standards for identifying a decline in mental function due to strokes or other conditions affecting the brain’s blood vessels.

Current methods for evaluating stroke damage do not include assessment of mental function, and standard Alzheimer tests miss many cases of impairment due to small or large strokes because the symptoms may differ from the typical Alzheimer pattern.

In a report in the Aug. 29 Stroke, a journal of the American Heart Association, the team presents their first recommendations for standard methods to detect stroke-related decline. They also endorse “vascular cognitive impairment” (VCI) as the standard name for the condition, because the term is broad and includes mild forms of the disease that may be the most treatable. Other terms used in current medical literature include “vascular dementia,” “post-stroke dementia,” and “multi-infarct dementia.”

The report also recommends standards for gathering data on VCI in research studies and brain autopsies, and analyzes the current usefulness of animal models, laboratory diagnostic tests, and genetic risk factors.

“More than 60 percent of individuals who have a stroke may experience some impact on their mental function, and this important initiative will help us identify them and ensure they get appropriate treatment, support and services for those symptoms,” says William H. Thies, Ph.D., Alzheimer’s Association vice president of medical and scientific relations. “Further, autopsy evidence shows that somewhere between 30 and 50 percent of those with Alzheimer’s also have signs of brain vascular issues.

"Standard assessment and research tools will help us better understand VCI and how VCI and Alzheimer’s interact," Thies continues. "Treating and preventing coronary heart disease has been one of the great medical success stories of the twentieth century. In theory, there’s no reason we can’t extend that success to vascular disease of the brain.”

The classic symptom most closely associated with Alzheimer’s disease is inability to learn and remember new information. In early stages, VCI often differs from Alzheimer’s by having a stronger impact on “executive function,” as evidenced by difficulty with reasoning and problem solving; slowed capacity to process and react to information; and impairment in the ability to focus attention and to shift from one task to another.

VCI may or may not significantly affect memory in any given individual, depending on whether vascular disease is present in the brain’s memory regions. The proposed standards provide more sensitive tools to assess executive function and other patterns of change associated with VCI.

The expert panel describes publication of these first standards as “…an open invitation for debate, study and validation.”

The agencies sponsoring the panel are the National Institute of Neurological Disorders and Stroke (NINDS), one of the U.S. National Institutes of Health, and Canadian Stroke Network, a nonprofit collaboration involving government, industry, and academic researchers.