President of the African Stroke Organisation (ASO), Prof. Rufus Akinyemi, said as many as one in two stroke survivors could develop some form of cognitive impairment, with the condition capable of undermining rehabilitation, independence and overall quality of life.
Akinyemi, a consultant neurologist at the University of Ibadan, disclosed this during an ASO-World Stroke Organisation (WSO) Webinar Series on Post-Stroke Dementia, where experts examined the growing burden of cognitive impairment and dementia following stroke.
He said cognitive impairment should no longer be treated as a secondary or incidental consequence of stroke, stressing that it could have profound effects on a survivor's ability to recover and function independently.
“Post-stroke cognitive impairment is a significant problem,” Akinyemi said, advocating the integration of routine cognitive assessment into stroke care.
According to the neurologist, studies conducted in different countries have consistently reported a substantial burden of cognitive impairment among stroke survivors. However, he noted that reported rates vary because of differences in diagnostic criteria, study populations and assessment methods.
Africa faces particular concern
Akinyemi said the problem deserved particular attention in Africa, where vascular disease contributes significantly to the continent's dementia burden.
He explained that systematic reviews had highlighted the importance of vascular dementia and vascular cognitive impairment in Africa, although the available evidence remained limited because many studies were conducted over relatively short periods and involved selected groups of patients.
Despite these limitations, he said cerebrovascular disease remained an important contributor to dementia across the continent.
The situation, he added, was compounded by the high prevalence of hypertension, diabetes and other vascular risk factors in many African populations.
Akinyemi also pointed to possible genetic factors that could contribute to a higher burden of small-vessel cerebrovascular disease among people of African ancestry, making the prevention and management of vascular risk factors especially important.
Nigerian study reveals extent of problem
Highlighting findings from the COFAS study conducted in Nigeria between 2010 and 2012, Akinyemi said researchers examined cognitive problems associated with vascular brain disease among about 147 stroke survivors.
The study found that approximately 24 per cent of the participants had dementia, while another 40 per cent had cognitive impairment without dementia.
The findings, he said, demonstrated that the effects of stroke on cognition could extend beyond the immediate area of the brain damaged by the event.
Older age and lower educational attainment were associated with a greater risk of cognitive problems, while some dietary and lifestyle factors appeared to have protective effects. Regular fish consumption, for instance, was associated with better outcomes.
Akinyemi, however, cautioned that apparent improvements in cognitive outcomes over time should be interpreted carefully, noting that people with poorer outcomes were more likely to die or drop out of long-term studies.
Multiple factors drive cognitive decline
Explaining why some stroke survivors develop cognitive impairment, Akinyemi said several mechanisms could be involved.
Recurrent strokes, multiple infarcts, small-vessel disease, white-matter lesions, cerebral atrophy and infarcts occurring in strategically important areas of the brain can all contribute to cognitive decline.
He said studies involving brain tissue had also shown that neurodegenerative disease alone could not fully explain why some stroke survivors developed dementia while others did not.
According to him, growing evidence points to neuroinflammation as an important mechanism.
Stroke can trigger inflammation and oxidative stress, which may damage white matter and interfere with communication between different regions of the brain. Such disruption can subsequently affect executive function and other cognitive abilities.
Hypertension remains key target
Akinyemi said preventing and controlling vascular risk factors before and after stroke remained one of the most important ways of reducing the burden of post-stroke cognitive impairment.
“Hypertension is always the number one risk factor for stroke,” he said, calling for stronger measures to detect, treat and control high blood pressure across Africa.
He noted that evidence showing hypertension accounts for a substantial proportion of the population-attributable risk for stroke suggested that better blood pressure control could prevent a considerable number of strokes and, by extension, reduce the number of people exposed to post-stroke cognitive complications.
The professor urged African countries to adopt population-wide approaches to hypertension prevention and control rather than depending largely on hospital-based treatment.
He also cited findings from the SIREN study, which showed an inverse relationship between green-vegetable consumption and hypertension.
Research among stroke survivors, he added, suggested that diets rich in vegetables and legumes might also have protective associations with cognitive performance.
He described such dietary measures as potentially inexpensive interventions, although he stressed that they required further investigation.
Rehabilitation must go beyond physical recovery
Akinyemi called on healthcare workers to make cognitive assessment a routine component of long-term stroke management.
He also urged rehabilitation programmes to address cognitive problems alongside physical disabilities, arguing that successful physical recovery does not necessarily mean that a survivor has regained the ability to live independently.
Rehabilitation, he said, should begin as early as clinically appropriate and involve a multidisciplinary team comprising doctors, nurses, physiotherapists, occupational therapists, psychologists and other relevant professionals.
“Cognitive rehabilitation should be integrated with motor rehabilitation because a patient who walks well but has significant cognitive impairment may still struggle to live independently,” he said.
He further cited evidence supporting cognitive stimulation for people living with mild cognitive impairment and early dementia, while calling for additional research into how such interventions could be adapted for stroke survivors.
Stigma compounds dementia burden
Beyond the medical challenges, Akinyemi expressed concern about the stigma surrounding dementia in parts of Africa.
He said some people living with dementia were wrongly labelled as witches and could subsequently face discrimination, abuse and violence.
Such beliefs, he warned, could cause families to conceal affected relatives or relocate them to rural communities, further limiting access to diagnosis, treatment and rehabilitation.
The neurologist called for greater public education to challenge misconceptions about dementia and promote earlier recognition of cognitive problems.
He also urged African researchers to intensify investigations into the genetic, biological, social and environmental factors associated with post-stroke cognitive impairment.
Another priority, he said, was the development of affordable and culturally appropriate cognitive screening tools that could be used in health facilities with limited resources.
Protecting brain health starts before stroke
Akinyemi said the response to post-stroke dementia must begin long before a stroke occurs and continue throughout the survivor's recovery.
For Africa, he said, addressing the problem would require a combination of prevention, early cognitive screening, appropriate rehabilitation, effective control of vascular risk factors, public education and sustained research.
He urged healthcare providers and policymakers to move away from viewing physical survival after stroke as the end of treatment.
Instead, he said, survival should mark the beginning of a long-term effort to preserve brain function, independence and quality of life.
The message, he stressed, is particularly important as African health systems confront the combined burden of stroke, hypertension, diabetes and dementia, making prevention and early intervention essential to reducing the long-term social and economic consequences of cerebrovascular disease.