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Research paper
Evaluation of cognitive impairment by the Montreal Cognitive Assessment in patients with aneurysmal subarachnoid haemorrhage: prevalence, risk factors and correlations with 3 month outcomes
  1. George Kwok Chu Wong1,
  2. Sandy Lam1,
  3. Karine Ngai1,
  4. Adrian Wong2,
  5. Vincent Mok2,
  6. W S Poon1,
  7. Cognitive Dysfunction after Aneurysmal Subarachnoid Haemorrhage Investigators
  1. 1Division of Neurosurgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
  2. 2Division of Neurology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
  1. Correspondence to Dr G K C Wong, Department of Surgery, 4/F Clinical Science Building, Prince of Wales Hospital, 1 Ngan Shing Street, Shatin, New Territories, Hong Kong SAR, China; georgewong{at}


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 US 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 of the US National Institutes of Health (NCT01038193).

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  • Cognitive Dysfunction after Aneurysmal Subarachnoid Haemorrhage Site Investigators: (1) Prince of Wales Hospital: George Wong, Wai Sang Poon, Vincent Mok. (2) Kwong Wah Hospital: John Kwok, Kwong Yau Chan, Peter Woo, Calvin Mak, Peter Pang. (3) Princess Margaret Hospital: Yin Chung Po, Tony Chan, Wai Kei Wong, Simon Lee. (4) Pamela Youde Nethersole Eastern Hospital: Chi Keung Wong, Michael Lee, Rebecca Ng, Alain Wong, Vincent Pang.

  • Funding This study was supported by the Neurosurgery Research and Training Fund, the Chinese University of Hong Kong.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by the Joint NTEC-CUHK Clinical Research Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.