Impact of Pre-Stroke Dementia or Mild Cognitive Impairment on Stroke Outcome: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVE

Pre-stroke dementia (PSD) and pre-stroke mild cognitive impairment (PSMCI) are important risk factors for stroke. The present meta-analysis aimed to investigate the impact of PSD or PSMCI on stroke outcomes.

METHODS

Electronic databases (PubMed, EMbase, Google Scholar, Cochrane Library, and TRIP) were screened for eligible studies published prior to March 31, 2021. Risk ratios (RR) and mean differences with 95% confidence intervals (CIs) using random or fixed effect models were used to calculate pooled estimates. Study quality was assessed using the Newcastle Ottawa Scale.

RESULTS

Fifteen studies were included in our meta-analysis. Pooled data from ten studies involving 3,107 PSD and 20,645 non-PSD subjects showed a higher risk of mortality in PSD patients (RR = 2.03; 95% CI: 1.40-2.91; I2 = 89%). Risk of recurrent stroke risk was observed more in patients with PSD compared to non-PSD patients (RR = 2.02; 95% CI: 1.40-2.91; I2 = 0%). Three studies involving 300 mild cognitive impairment (MCI) and 1,025 normal cognition subjects showed a significant increased risk of mortality in stroke patients with MCI (RR = 2.43; 95% CI: 1.81-3.27; I2 = 20%). However, elevated stroke severity was not observed in PSMCI patients.

CONCLUSIONS

Our meta-analysis shows an increased risk of mortality in stroke patients with a history of PSD and PSMCI. Proper clinical management and increased attention are therefore required for the prevention and management of stroke in patients with cognitive deficits.