Demencia

doi:10.1093/brain/awr273

Brain 2011: 134; 3716–3727

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BRAIN
A JOURNAL OF NEUROLOGY

Long term incidence of dementia, predictors of mortality and pathological diagnosis in older stroke survivors
Louise M. Allan, Elise N. Rowan, Michael J. Firbank, Alan J. Thomas, Stephen W. Parry, Tuomo M. Polvikoski, John T. O’Brien and Raj N. Kalaria
Downloaded fromhttp://brain.oxfordjournals.org/ by guest on January 22, 2012
Institute for Ageing and Health, Newcastle University, Wolfson Research Centre, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK Correspondence to: Prof. Raj N. Kalaria Institute for Ageing and Health Newcastle University Campus for Ageing and Vitality Newcastle upon Tyne NE4 5PL UK E-mail: raj.kalaria@ncl.ac.uk Correspondence may also beaddressed to: Dr Louise M. Allan. E-mail: louise.allan@ncl.ac.uk

Greater understanding of the risk factors and mechanisms of incident dementia in stroke survivors is needed for prevention and management. There is limited information on the long-term consequences and forms of incident dementia in older stroke survivors. We recruited 355 patients aged 475 years from hospital-based stroke registers intoa longitudinal study 3 months after stroke. At baseline none of the patients had dementia. Patients were genotyped for apolipoprotein E and assessed annually for cognition and development of incident dementia over up to 8 years of follow-up. The effect of baseline vascular risk factors upon incidence of dementia and mortality were estimated by Cox proportional regression analyses adjusted for ageand gender. Standard neuropathological examination was performed to diagnose the first 50 cases that came to autopsy. We found that the median survival from the date of the index stroke was 6.72 years (95% confidence intervals: 6.38–7.05). During the follow-up of a mean time of 3.79 years, 23.9% of subjects were known to have developed dementia and 76.1% remained alive without dementia or diedwithout dementia. The incidence of delayed dementia was calculated to be 6.32 cases per 100 person years whereas that for death or dementia was 8.62. Univariate and multivariate regression analyses showed that the most robust predictors of dementia included low (1.5 standard deviations below age-matched control group) baseline Cambridge Cognitive Examination executive function and memory scores,Geriatric Depression Scale score and three or more cardiovascular risk factors. Autopsy findings suggested that remarkably 575% of the demented stroke survivors met the current criteria for vascular dementia. Demented subjects tended to exhibit marginally greater neurofibrillary pathology including tauopathy and Lewy bodies and microinfarcts than non-demented survivors. Despite initial improvements incognition following stroke in older stroke survivors, risk of progression to delayed dementia after stroke is substantial, but is related to the presence of vascular risk factors. Careful monitoring and treatment of modifiable vascular risk factors may be of benefit in preventing post-stroke dementia in the general population.

Keywords: Alzheimer’s disease; diagnosis; post-stroke dementia; stroke;vascular dementia Abbreviations: CIND = cognitive impairment no dementia; CAMCOG = Cambridge Cognitive Examination

Received May 18, 2011. Revised August 1, 2011. Accepted August 21, 2011 ß The Author (2011). Published by Oxford University Press on behalf of the Guarantors of Brain. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-CommercialLicense (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Long-term consequences of stroke in the elderly

Brain 2011: 134; 3716–3727

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Introduction
Stroke and dementia individually are common, costly, and personally often devastating to patients...