Profile and determinants of vascular cognitive impairment in African stroke survivors: The CogFAST Nigeria Study

Abstract Objective Sub-Saharan Africa faces a potential epidemic of non-communicable diseases including stroke and dementia but little is known about the burden of stroke-related cognitive dysfunction. We assessed the baseline profile and factors associated with vascular cognitive impairment (VCI) in stroke survivors participating in the Cognitive Function After STroke (CogFAST) Nigeria Study. Methods We recruited 217 subjects ( >  45 years old) comprising 143 stroke survivors and 74 demographically matched stroke-free healthy controls. We obtained demographic, clinical and lifestyle information and assessed the cognitive status of the subjects at baseline three months after stroke. Standard neuropsychological tests included the Vascular Neuropsychological Battery, which assessed executive function/mental speed, memory, language, and visuospatial/visuoconstructive functioning. Cognitive impairment and dementia were defined based on the AHA/ASA VCI guidelines and the DSM IV criteria. Results Among the stroke survivors (mean age = 60.4  +  9.5 years, 43.4% female, mean number of years of education = 9.4  +  5.6 years, median modified Rankin score = 2), 57 (39.9%) had cognitive impairment no dementia while 12 (8.4%) were demented at baseline. Multivariate analysis revealed that older age [OR = 1.05 (1.00–1.09)], low education [OR = 5.09 (2.17–11.95)], pre-stroke cognitive decline [OR = 4.51 (1.20–16.88)] and medial temporal lobe atrophy [OR = 2.25 (1.16–4.35)] were independently associated with cognitive dysfunction whereas pre-stroke daily intake of fish [p = 0.022, OR = 0.39 (0.15–0.89)] was inversely associated. Conclusions These results suggest a high frequency of early VCI in older Nigerian stroke survivors. Apart from aging, associated neurodegeneration and cognitive decline, educational level and pre-stroke diet particularly fish consumption were identified as modifiable factors. This emphasizes the vital role of education and healthy nutrition in building reserves to ameliorate cognitive dysfunction after stroke.