Early MoCA-assessed cognitive impairment after aneurysmal subarachnoid hemorrhage and relationship to 1-year functional outcome.

Recent clinical research into aneurysmal subarachnoid hemorrhage (aSAH) has confirmed the long-term effect of cognitive dysfunction on functional outcomes. We hypothesized that early cognitive impairment was a marker of permanent brain injury and hence predicted long-term functional outcome. Hong Kong Chinese patients with aneurysmal subarachnoid hemorrhage were evaluated prospectively by means of the Montreal Cognitive Assessment (MoCA) in the subacute phase (2-4 weeks after aSAH) and by neuropsychological evaluation of functional outcomes in the chronic phase (1 year after aSAH). This multi-center prospective observational study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). One hundred and eight patients completed both the subacute and chronic phase assessments. Cognitive dysfunction in the subacute phase independently correlated with functional outcomes at 1 year, after adjusting for age, admission clinical condition, treatment modality, motor score, and mobility in the subacute phase, but the positive predictive values remained low. MoCA-assessed cognitive impairment in the subacute phase cannot accurately predict functional outcomes at 1 year. Future study should focus on understanding the relative importance of different components of early cognitive impairment.