Increased prevalence of microangiopathic brain lesions among siblings of patients with lacunar stroke. A prospective multicenter study.

Background: Family and twin studies suggest predisposing genetic factors in stroke. Lacunar infarcts represent a homogeneous phenotype, which is a prerequisite for genetic analyses. Applying an affected sib -pair analysis, we prospectively assessed the prevalence of microangiopathic brain lesions (MBL) and associated risk factors among siblings of patients with lacunar stroke.

Methods: Index patients fulfilled clinical criteria of a lacunar stroke in combination with a corresponding MBL on CT or MRI. Siblings were characterized as affected if MBL demonstrated on MRI. The prevalence of MBL was compared with population prevalence data extracted from other studies.

Results: From 784 patients screened, 81 index patients with lacunar stroke and 97 siblings were recruited, of which 42% were identified as affected. Compared with data from unselected historical controls and stratified by age groups, prevalence was between 2 and 5 times higher.

Conclusions: Our results indicate that genetic stroke studies are feasible even in subtypes of ischemic stroke. The high prevalence of MBL among siblings of patients with lacunar infarct might suggest a familial aggregation. However, due to the small sample size these results need to be interpreted with caution and require confirmation by planned genetic analyses.