Table 1 Inclusion and exclusion criteria

1) Those from 35 to 85 years of age admitted within 7 days after stroke onset

1) Those aged < 35, or > 85

2) Those with radiologically-confirmed cerebral infarction in brain MRI (including T2*-gradient echo MRI)

2) Those with systolic blood pressure > 220 mmHg, or diastolic blood pressure > 120 mmHg

3) Those with hypertension

3) Those with secondary hypertension (eg. renal, renovascular, endocrinologic, gestational, and etc.)

4) Those who understand the study protocol and signed the informed consent

4) Night-shift workers (sleeping during the day and work from midnight to 4 AM due to job or other reasons)

5) Those who were prescribed an intravenous recombinant tissue-plasminogen activator or anticoagulants

6) Those who had severe stroke (NIHSS ≥ 20)

7) Those who had life threatening medical conditions (hypertensive encephalopathy, aortic dissection, acute myocardial infarction, severe congestive heart failure and etc.)

8) Those with confirmed cardioembolic risk factors such as atrial fibrillation