Cognitive decline before and after a first‐ever stroke in Africans

Abstract

Objectives There is a knowledge gap on the impact of pre‐existing cognitive decline on poststroke decline in indigenous Africans. We describe the trajectories of domain‐specific cognitive and activities of daily life (ADL) functioning across the first year of stroke in Nigerians with pre‐existing cognitive decline. Materials and Methods Prospective observational study. Prestroke cognitive decline was ascertained retrospectively using the 16‐item Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE). Assessments for global cognition, learning, memory, executive and ADL functioning were conducted at 3 time points using the Mini‐Mental state examination (MMSE), 10‐words list learning and delayed recall test (10 WDRT), Animal naming test and Barthel index, respectively. Results Among 150 stroke survivors, prestroke cognitive decline was found in 25 (16.7%, 95% C.I = 11.5%–23.6%). In linear regression analyses adjusting for the effect of age, education, stroke severity and comorbid diabetes mellitus, prestroke cognitive decline predicted poor memory scores at one year [Adjusted standardized mean difference (SMD) = −0.6, 95% C.I = −1.1, −0.1, p = 0.016)]. The association of prestroke cognitive decline with poststroke poor memory was substantially mediated by age (SMD = −0.9, 95% C.I = −1.4, −0.4, p < 0.001). Conclusion Pre‐existing cognitive decline in this sample was associated with an age‐mediated poor memory function at one‐year poststroke. Early institution of targeted cognitive rehabilitation in stroke survivors with pre‐existing cognitive decline may reduce the neurocognitive burden of stroke in Black Africans.

Association of β-cell function and cognitive impairment in patients with abnormal glucose metabolism

“…Besides, insulin deficiency also damages vascular function through effects on vasoreactivity, lipid metabolism, and inflammation [ 30 ]. As reported, lower β-cell function may lead to elevated intima-media thickness [ 31 ] and increased risk of recurrent stroke [ 32 ], both of which have been found associated with cognitive impairment [ 33 , 34 ]. In addition, insulin plays an important role in synaptic plasticity of hippocampus.…”