Post-stroke dementia (PSD) is an increasingly frequently diagnosed type of dementia. PSD occurs in at least 1/3 of patients with a stroke within 1 year of the incident, and doctors alert that there will be more patients. What is post-stroke dementia? What are its causes? What are the risk factors for developing dementia after stroke?
Post-stroke dementia( PSD- post-stroke dementia) is any type of dementia that develops after a stroke, regardless of the likely cause .
Research shows that post-stroke dementia most often appears several months after the onset of a stroke. The incidence of PSD 3 months after ischemic stroke ranges from 6 to 31.8%, depending on the study. In turn, the risk of dementia one year after having a stroke is estimated at 16.8-24% (the differences in the results are the result of the use of various diagnostic criteria by the researchers). The risk remains elevated for many years after having a stroke.
Post-stroke dementia - causes
The cause of post-stroke dementia, contrary to what the name might suggest, is not a stroke. Stroke only increases the risk of developing dementia (and dementia is a risk factor for stroke). Research shows that the most common cause of post-stroke dementia is vascular dementia, with which post-stroke dementia is often misidentified. Vascular dementia plays a significant role in the development of PSD in the following circumstances: when a post-stroke patient is too young to have Alzheimer's disease, when dementia appeared shortly after the stroke, and when cognitive functions were normal prior to the stroke and were impaired immediately after the stroke. stroke. Post-stroke dementia of vascular aetiology is most likely when the focus, most often ischemic, includes centers "topographically strategic" for cognitive functions: the thalamus, the insular cortex, the mesial structures of the temporal lobe, the base of the frontal lobe of the dominant hemisphere and the area where the temporal, parietal and occipital lobes meet.
The second most common cause of post-stroke dementia is degenerative dementia, or Alzheimer's disease, which is seen in 19-61% of PSD patients (depending on the study). Dementia is in third placemixed.
Post-stroke dementia - risk factors for developing post-stroke dementia
Research by scientists clearly shows that the most important risk factor for dementia in people after stroke is age. The size of the ischemic focus, pre-existing diseases of the white matter of the brain, low blood pressure in the cerebral vessels, and temporal lobe atrophy (usually associated with AD) are also important. The presence and severity of cognitive symptoms after stroke is also positively correlated with the risk of dementia. Surprisingly, the size of the area of tissue damaged during the stroke and the location of the damage are of less importance. The role of other factors is ambiguous:
- demographic factors: older age, lower level of education, dependence on other people
- vascular risk factors: hypertension, diabetes, heart attack, cardiac arrhythmias, circulatory failure, history of stroke
- data from neuroimaging: the so-called silent strokes, i.e. asymptomatic, brain atrophy, atrophy of the medial part of the temporal lobe, changes in the white matter of the brain, size of the stroke, number and location of old ischemic lesions
- data related to stroke: greater neurological deficit on admission to hospital, worse course of stroke, recurrent stroke, supratentorial location of stroke, left hemisphere stroke, anterior and posterior vascularization stroke, extensive central artery vascularization stroke brain, strategic strokes, multifocal injuries, frontal lobe stroke, dysphasia
- other: intellectual decline not meeting the criteria for pre-stroke dementia, epileptic seizures, sepsis, previous presence of nephropathy
Based on:
Klimkowicz-Morawiec A., Szczudlik A.,Post-stroke dementia , [in:]Dementia. Theory and practice , pp. edited by Leszek J., Wrocław 2011
Kolan M.,Cognitive disorders and ischemic diseases of the brain , Symposium: Neurocells in pathology and he alth, 2009-2011, Pomeranian Medical University in Szczecin
Leys D., Hénon H., Mackowiak-Cordoliani M, Pasquier F.,Poststroke dementia , "The Lancet Neurology" 2005, No. 4