Prevalence and determinants of subclinical brain infarction: the Northern Manhattan Study.
OBJECTIVE
Risk factors for subclinical brain infarcts (SBI) have not been well studied, especially in Hispanic and black populations who may be at higher risk for vascular disease. We examined the prevalence and determinants of SBI in a multiethnic community cohort.


METHODS
The Northern Manhattan Study (NOMAS) includes 892 stroke-free participants who underwent brain MRI. Baseline demographic and vascular risk factor data were collected. The presence of SBI was determined from the size, location, and imaging characteristics of the lesion based on fluid attenuated inversion recovery (FLAIR) T1 and T2, and proton density MRI sequences. We calculated the prevalence of SBI and cross-sectional associations with sociodemographic and vascular risk factors, using logistic regression to adjust for relevant covariates.


RESULTS
Among 892 subjects (mean age 71.3 years), 158 (17.7%) had SBI (13.5% had 1 lesion, 4.3% had >1 lesion). Of the total 216 infarcts, most were small (<1 cm, 82.4%) and subcortical (82.9%). SBI prevalence increased with age (<65: 9.7%; 65 to 75: 16.4%; >75: 26.1%), was increased among men (21.3% vs 15.2% in women), and was increased among blacks (24.0% vs 18.1% in whites and 15.8% in Hispanics). The presence of SBI was independently associated with older age (per year: OR 1.06, 95% CI 1.04 to 1.09), male sex (OR 1.79, 95% CI 1.22 to 2.61), and hypertension (OR 2.08, 95% CI 1.35 to 3.22) adjusting for age, sex, race-ethnicity, and vascular risk factors. A significant interaction (p = 0.002) between race and age was observed such that younger black subjects had greater odds of having SBI.


CONCLUSIONS
SBI were detected in nearly 18% of subjects in a multiethnic community-based cohort. Age, male sex, and hypertension were independently associated with SBI. Subclinical cerebral infarcts are more prevalent than symptomatic infarcts and may increase the true public health burden of stroke.
Prabhakaran
S
S
Rush University Medical Center, Chicago, IL, USA.
Wright
C B
CB
Yoshita
M
M
Delapaz
R
R
Brown
T
T
DeCarli
C
C
Sacco
R L
RL
D017677:Age Distribution; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D001921:Brain / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D020520:Brain Infarction / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology*; D002536:Cerebral Arteries / Q000473:pathology* / Q000503:physiopathology; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D038524:Diffusion Magnetic Resonance Imaging; D005006:Ethnicity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D015995:Prevalence; D044469:Racial Groups; D012307:Risk Factors; D017678:Sex Distribution; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology*