Transcript Chapter 2: Background - Ontario Stroke Network

Screening for Stroke and
Cognitive Impairment
Chapter 2:
Background
Vascular Cognitive Impairment
• “Vascular Cognitive Impairment (VCI) includes the cognitive and
behavioural disorders associated with cerebrovascular disease and
risk factors, from mild cognitive deficits to frank dementia.”1
• “VCI is a syndrome with cognitive impairment affecting at least one
cognitive domain (e.g., attention, memory, language, perception or
executive function) and with evidence of clinical stroke or subclinical
vascular brain injury.”1
• “VCI encompasses a large range of cognitive deficits, from relatively
mild cognitive impairment of vascular origin (VaMCI) to Vascular
Dementia (VaD) the most severe form of VCI.”1
• “VCI also plays a role in patients with Alzheimer’s disease pathology
who have coexisting vascular lesions.”1
Vascular Cognitive Impairment
• The first step for health care providers in Taking Action for cognitive
changes is to understand the frequency of occurrence for VCI in patients.1
• “VCI affects up to 60% of stroke survivors and is associated with poorer
recovery and decreased function in activities of daily living and
instrumental activities of daily living.”1
• “Cognitive abilities in the areas of executive function, attention and
memory appear important in predicting functional status at discharge.”1
• “Cognitive impairment increases long-term dependence and is associated
with increased mortality rates (61% versus 25%)”1,4
Vascular Cognitive Impairment
• “Cognitive impairment can be chronic and progressive after stroke; post
stroke dementia is estimated to occur in 26% of stroke patients by 3
months and adversely affects recovery.”1
Classification and Diagnostic Criteria for Vascular Cognitive
Impairment and Dementia can be found at:1
http://www.strokebestpractices.ca/wp-content/uploads/2012/04/Table72A-EN.pdf
Covert Strokes
• Cognitive impairment due to covert vascular pathology is
becoming more prevalent1.
• Covert strokes, e.g., lacunes are common (23% of
community elderly) and are associated with cognitive
decline, dementia, and stroke1.
• For every clinically evident stroke there could be as many
as 10 previous “covert” strokes1.
• Signs of covert stroke can often present as signs and
symptoms of cognitive impairment1.
Incidence of
Cognitive Impairment
in a Stroke Prevention Clinic
In this study two-thirds of stroke prevention clinic patients demonstrated evidence for
cognitive impairment irrespective of their final diagnosis or the presence of white
matter changes, which further supports the need for cognitive screening in a
secondary stroke prevention clinic setting10.
Dementia
• Stroke and dementia are interconnected, sharing common
risk factors and each increases the risk of the other4.
• About 10% of patients hospitalized with their first stroke
have pre-stroke dementia, and an additional 10% will have
new dementia as a consequence of the stroke4.
• Approximately 25% of hospitalized stroke patients will have
dementia when evaluated during the first year post stroke4.
• In stroke patients with recurrent stroke the rates of
dementia can be greater than 30%4.
Dementia
• Vascular dementia is the second most common cause of
dementia after Alzheimer Disease1.
• The combination of Alzheimer disease and vascular
disease results in the most common type of dementia in
the elderly1.
• “A single macroscopic hemispheric infarct is sufficient to
cause dementia in people with intermediate Alzheimer
pathology.”1
Dementia
• Approximately one in three persons will develop stroke,
dementia, or both, and the incidence for both increases
exponentially with age4.
• Increasing age, lower education level, cerebral atrophy,
white matter disease, premorbid disability, and
diminished cognition pre-stroke are non-stroke factors
associated with post-stroke dementia4.
Post-stroke Dementia
Incidence in Inpatients
Chart shows incidence (linear regression –solid line, 95% CI –dashed lines) of post-stroke
dementia in hospital pts of either first or recurrent stroke, and excludes pre-stroke dementia.
There is a rapid rise in dementia incidence in the immediate post-stroke period.
Incidence of dementia increases linearly at a rate of 3.0% (1.3-4.7%) per year above the initial
post-stroke incidence of approximately 20% at three to six months4.