OBJECTIVES: Experimental evidence has indicated the benefit of simvastatin in 
the treatment of subarachnoid hemorrhage (SAH). Recently, acute simvastatin 
treatment was not shown to be beneficial in neurological outcome using modified 
Rankin Scale. Cognitive function is another important dimension of outcome 
assessment and yet had not been investigated in statin studies for aneurysmal 
subarachnoid hemorrhage. We therefore explored whether acute simvastatin 
treatment would improve cognitive outcomes.
METHODS: The study recruited SAH patients with acute simvastatin treatment 
enrolled in a randomized controlled double-blinded clinical trial 
(ClinicalTrials.gov Identifier: NCT01038193). A control cohort of SAH patients 
without simvastatin treatment was identified with propensity score matching of 
age and admission grade. Primary outcome measure was Montreal Cognitive 
Assessment (MoCA). Secondary outcome measures were delayed ischaemic deficit 
(DID), delayed cerebral infarction, modified Rankin Scale (mRS), and Mini-Mental 
State Examination (MMSE).
RESULTS: Fifty-one SAH patients with acute simvastatin treatment and 51 SAH 
patients without simvastatin treatment were recruited for analysis. At 3 months, 
there were no differences in MoCA scores (MoCA: 21+/-6 vs. 21+/-5, p=0.772). 
MoCA-assessed cognitive impairment (MoCA<26) was not different (75% vs. 80%, OR 
0.7, 95%CI 0.3 to 1.8, p=0.477). There were also no differences in DID, delayed 
cerebral infarction, favorable mRS outcome, and MMSE scores, and MMSE-assessed 
cognitive impairment between both groups.
CONCLUSIONS: The current study does not support that acute simvastatin treatment 
improves cognitive outcome after aneurysmal subarachnoid hemorrhage.