4 minute read
STROKOG
by CHeBA
STROKOG is a consortium of longitudinal studies of cognitive disorders following stroke, TIA or small vessel disease. Developed under the auspices of VASCOG (Society for the Study of Vascular Cognitive and Behavioural Disorders), it is the first international effort to harmonise work on post-stroke dementia.
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Currently there are 33 international studies participating in STROKOG, which include the following countries: Australia, Bulgaria, China, Finland, France, Germany, Hong Kong, Ireland, Korea, Nigeria, Poland, Singapore, South Africa, Sweden, The Netherlands, Scotland, Ireland, United Kingdom and the USA.
In 2019, the following new studies joined STROKOG: Bulgarian Poststroke Study, Bulgaria; The HKU Stroke Cohort, Hong Kong; STRATEGIC, Australia.
In 2019, the prestigious Neurology journal published the first STROKOG research paper written by CHeBA researchers. The paper focuses on the profile of and risk factors for post-stroke cognitive impairment in diverse ethno-regional groups; we found that diabetes, a history of past stroke, and to a lesser degree, hypertension, smoking and atrial fibrillation are related to poorer cognitive function at 1-6 months after stroke.
Three external researchers from the UK and from Finland collaborated with CHeBA and worked on three separate STROKOG projects in 2019. Dr Eugene Tang from Newcastle University, UK led a project on validating dementia risk score models. Dr Tang found that dementia risk prediction models developed for the general population do not perform well in individuals with stroke. His paper is due to be published in 2020. Dr Clare Flach from King’s College London, UK has been examining stroke recovery associated with cognitive impairment. Dr Hanna Jokinen from the University of Helsinki in Finland is investigating domain-specific cognitive impairment and depression as determinants of post-stroke functional disability. The latter two projects are on-going.
Jess Lo, STROKOG Study Coordinator
In 2019 CHeBA researchers worked on a paper looking at diabetes, prediabetes on cognitive function after stroke. Based on data from 7 international studies, we found that diabetes is strongly associated with worse cognitive function after stroke, but not prediabetes. This paper is due to be published in the high-impact journal Stroke in 2020. CHeBA researchers also began working on the next major project looking at cognitive decline after stroke. Longitudinal data on cognitive assessment were requested from 9 international studies and harmonised. The CHeBA imaging team also proposed to form a Neuroimaging Work Group within STROKOG and a project harmonising MRI scans and analysing white matter hyperintensities and stroke. These projects are on-going in 2020.
CHeBA was invited to present at the Vascular Neurodegeneration Symposium at the Florey Institute of Neuroscience and Mental Health, the University of Melbourne in February.
For a full list of studies involved, see: www.cheba.
unsw.edu.au/consortia/strokog/studies
Type 2 Diabetes, Stroke and Cognitive Performance
New research led by CHeBA found that people with Type 2 diabetes, but not those with prediabetes, had worse cognitive performance three to six months after a stroke than those with normal fasting blood sugar levels. The findings were published in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.
Type 2 diabetes increases the risk of stroke and has been associated with cognitive impairment and may increase dementia risk – which is why Type 2 diabetes is another important target in the prevention of dementia, and the focus should be on early treatment for prediabetes to delay or prevent the progression to Type 2 diabetes.
Previous research by Professor Sachdev and colleagues found that stroke patients with a history of Type 2 diabetes have worse cognitive function compared to stroke patients without Type 2 diabetes.
"In this study, we wanted to know if stroke patients with prediabetes also have worse cognitive function compared to stroke patients without prediabetes or diabetes," Professor Sachdev said.
"This is important because prediabetes is very common, and individuals can have prediabetes for several years before progressing to Type 2 diabetes. Early and aggressive treatment of prediabetes can delay or prevent Type 2 diabetes. Almost all had clot-caused strokes, and a variety of cognitive functions were assessed between three to six months after the stroke. Patients' fasting blood sugar levels measured at hospital admission and medical history were used to define Type 2 diabetes and prediabetes.
Jess Lo
“While our study is focused on cognition after a stroke, there is strong evidence that Type 2 diabetes is associated with cognitive impairment. This is an important message for the general public. Since our study shows no evidence that prediabetes is associated with worse cognitive performance, this emphasises the importance of the early diagnosis and treatment of prediabetes (which is often under-diagnosed) in order to delay or prevent the progression to Type 2 diabetes,” Jess Lo said. The seven studies included in the analysis were all part of STROKOG. The studies were conducted in Australia, France, Korea, the Netherlands, Singapore and the United States.
DOI: 10.1161/STROKEAHA.119.028428Stroke. 2020;51:1640–1646
Lead author and Study Coordinator of STROKOG, Jess Lo, said the research combined data from 1,601 stroke patients (average age 66; 63% male; 70% Asian; 26% white; 2.6% African American) who participated in one of seven international studies from six countries.
The study was funded by the Vincent Fairfax Family Foundation and the National Health and Research Council of Australia.
