title: Evaluation of cognitive impairment by the Montreal cognitive assessment in patients with aneurysmal subarachnoid haemorrhage: prevalence, risk factors and correlations with 3 month outcomes.
abstract: OBJECTIVE
  Identification of patients with aneurysmal subarachnoid haemorrhage (aSAH) with cognitive impairment is important for patient management (medical treatment, cognitive rehabilitation and social arrangements). The Montreal cognitive assessment (MoCA) is currently recommended over the mini-mental state examination (MMSE) by the U.S. National Institute of Neurological Disorder, in the chronic post-stroke setting. We hypothesised that the MoCA has a better correlation with functional outcome at 3 months than the MMSE.
  
  
  METHODS
  We carried out a prospective observational study in Hong Kong over a 2 year period, recruiting patients aged 21-75 years with aSAH admitted within 96 h of ictus. The assessments included the modified Rankin Scale, Lawton Instrumental Activity of Daily Living (IADL), Short Form-36, MoCA and MMSE at 3 months after ictus. Analyses were carried out to compare MoCA with MMSE.
  
  
  RESULTS
  90 patients completed the 3 month assessments. Cognitive impairment (MoCA <26) was determined in 73% of patients at 3 months. Delayed cerebral infarction explained the 31-38% variance in cognitive outcomes (MMSE and MoCA) at 3 months. MoCA demonstrated good discrimination of favourable neurological and IADL outcomes similar to the MMSE in receiver operating characteristics curve analyses.
  
  
  CONCLUSIONS
  MoCA defined cognitive impairment was common at 3 months after aSAH and MoCA correlated with functional outcomes similar, but not superior, to the MMSE. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).
authors.affiliation: Department of Surgery, 4/F Clinical Science Building, Prince of Wales Hospital, 1 Ngan Shing Street, Shatin, New Territories, Hong Kong SAR, China. georgewong@surgery.cuhk.edu.hk
authors.forename: George Kwok Chu
authors.initials: GK
authors.lastname: Wong
authors.forename: Sandy
authors.initials: S
authors.lastname: Lam
authors.forename: Karine
authors.initials: K
authors.lastname: Ngai
authors.forename: Adrian
authors.initials: A
authors.lastname: Wong
authors.forename: Vincent
authors.initials: V
authors.lastname: Mok
authors.forename: W S
authors.initials: WS
authors.lastname: Poon
mesh_terms: D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000453:epidemiology / Q000523:psychology*