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

Area of Science:

• Neurology
• Geriatrics
• Public Health

Background:

• A knowledge gap exists regarding the impact of pre-existing cognitive decline on post-stroke outcomes in Indigenous Africans.
• Pre-existing cognitive decline may influence the trajectory of cognitive and functional recovery following a stroke.

Purpose of the Study:

• To describe cognitive and activities of daily life (ADL) functioning trajectories in Nigerians with pre-existing cognitive decline during the first year post-stroke.
• To investigate the association between pre-stroke cognitive decline and post-stroke cognitive and ADL functioning.

Main Methods:

• A prospective observational study was conducted with 150 stroke survivors in Nigeria.
• Pre-stroke cognitive decline was retrospectively assessed using the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE).
• Cognitive and ADL functioning were assessed at three 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.

Main Results:

• Approximately 16.7% of stroke survivors exhibited pre-stroke cognitive decline.
• Pre-stroke cognitive decline was a significant predictor of poorer memory scores at one year post-stroke (Adjusted SMD = -0.6, p=0.016).
• The association between pre-stroke cognitive decline and post-stroke memory decline was substantially mediated by age (SMD = -0.9, p < 0.001).

Conclusions:

• Pre-existing cognitive decline is linked to age-mediated memory impairment one year after stroke in this Nigerian cohort.
• Targeted cognitive rehabilitation initiated early in stroke survivors with pre-existing cognitive decline may reduce the neurocognitive burden.
• Findings highlight the importance of identifying and managing cognitive decline in stroke survivors within the Black African population.