title: Cognitive impairment after lacunar stroke: systematic review and meta-analysis of incidence, prevalence and comparison with other stroke subtypes.
abstract: BACKGROUND
  Cognitive impairment and dementia are common after stroke. It is unclear if risk differs between ischaemic stroke subtypes. Lacunar strokes might be less likely to affect cognition than more severe, larger cortical strokes, except that lacunar strokes are associated with cerebral small vessel disease (SVD), which is the commonest vascular cause of dementia.
  
  
  METHODS
  We searched MEDLINE and PsychINFO for studies of mild cognitive impairment (MCI) or dementia after lacunar or cortical ischaemic stroke. We calculated the OR for cognitive impairment/dementia in lacunar versus non-lacunar stroke, and their incidence and prevalence in lacunar stroke as a pooled proportion.
  
  
  RESULTS
  We identified 24 relevant studies of 7575 patients, including 2860 with lacunar stroke; 24% had MCI or dementia post stroke. Similar proportions of patients with lacunar and non-lacunar stroke (16 studies, n=6478) had MCI or dementia up to 4 years after stroke (OR 0.72 (95% CI 0.43 to 1.20)). The prevalence of dementia after lacunar stroke (six studies, n=1421) was 20% (95% CI 9 to 33) and the incidence of MCI or dementia (four studies, n=275) was 37% (95% CI 23 to 53). Data were limited by short follow-up, subtype classification methods and confounding.
  
  
  CONCLUSIONS
  Cognitive impairment appears to be common after lacunar strokes despite their small size, suggesting that associated SVD may increase their impact. New prospective studies are required with accurate stroke subtyping to assess long term outcomes while accounting for confounders.
authors: Division of Clinical Neurosciences, University of Edinburgh, Bramwell Dott Building, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK. stephen.makin@ed.ac.uk
authors: Stephen David James
authors: SD
authors: Makin
authors: Sarah
authors: S
authors: Turpin
authors: Martin S
authors: MS
authors: Dennis
authors: Joanna M
authors: JM
authors: Wardlaw
mesh_terms: D059345:Cerebral Small Vessel Diseases / Q000150:complications / Q000523:psychology; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000523:psychology; D003627:Data Interpretation, Statistical; D003704:Dementia / Q000523:psychology; D006801:Humans; D015994:Incidence; D007360:Intelligence; D007361:Intelligence Tests; D009483:Neuropsychological Tests; D016017:Odds Ratio; D015995:Prevalence; D020521:Stroke / Q000150:complications / Q000453:epidemiology / Q000523:psychology; D059409:Stroke, Lacunar / Q000150:complications / Q000453:epidemiology / Q000523:psychology*; D014057:Tomography, X-Ray Computed
keywords: Cognition; Dementia; Stroke