Stroke occurring in patients with cognitive impairment or dementia.

OBJECTIVE: To determine how pre-stroke cognitive impairment can be detected, its mechanism, and influence on outcome and management. METHODS: Literature search. RESULTS: (i) A systematic approach with the Informant Questionnaire of Cognitive Decline in the Elderly is recommended; (ii) Pre-stroke cognitive impairment may be due to brain lesions of vascular, degenerative, or mixed origin; (iii) Patients with pre-stroke dementia, have worse outcomes, more seizures, delirium, and depression, and higher mortality rates; they often need to be institutionalised after their stroke; (iv) Although the safety profile of treatment is not as good as that of cognitively normal patients, the risk:benefit ratio is in favour of treating these patients like others. CONCLUSION: Patients with cognitive impairment who develop a stroke have worse outcomes, but should be treated like others.