Background: We recently observed that 13% of 1,008 consecutive adults aged 15-49 years with first-ever ischemic stroke had one or more silent brain infarcts (SBIs), and more than 5% presented with leukoaraiosis on CT or MRI. We sought to investigate the features of and risk factors for magnetic resonance (MR)-defined SBIs and leukoaraiosis in these patients.
Methods: We analyzed the radiologic features of SBIs and leukoaraiosis in MR-scanned patients (n = 669) blinded to clinical data and examined their relation with subtype of the overt stroke. We used logistic regression to identify factors predisposing to SBIs and leukoaraiosis.
Results: Of the 669 patients included, 86 (13%) had SBIs, 50 (7%) had leukoaraiosis, 17 (3%) had both, and 550 had no SBIs or leukoaraiosis and served as controls. The majority (54%) had a single SBI, 20% had two SBIs, and 27% had three or more SBIs. Most SBIs were located in basal ganglia (39%) or subcortical regions (21%), but cerebellar SBIs also were rather frequent (15%). Leukoaraiosis was mainly mild to moderate. Independent risk factors for SBIs were type 1 diabetes (odds ratio [OR] 5.78, 95% confidence interval 2.37-14.10), obesity (OR 2.12, 1.07-4.19), smoking (OR 1.69, 1.05-2.72), and increasing age (OR 1.08, 1.04-1.13). Risk factors for leukoaraiosis were type 1 diabetes (OR 9.75, 3.39-28.04), obesity (OR 2.42, 1.04-5.68), female sex (OR 2.25, 1.16-4.34), and increasing age (OR 1.19, 1.10-1.29). Small-vessel disease was the predominant cause of stroke in both those with SBIs (31%) and leukoaraiosis (44%).
Conclusions: Silent brain infarcts and leukoaraiosis are not uncommon among young stroke patients--type 1 diabetes being the strongest risk factor.