Stroke subtypes and risk factors associated with silent infarctions in patients with first-ever ischemic stroke or transient ischemic attack.

The relationship between the presence of silent cerebral infarcts (SCI) and etiology of an acute cerebral ischemia remains controversial. In a population of 306 patients with a first-ever stroke (225) or transient ischemic attack (TIA) (81), we studied the prevalence and associated risk factors of SCI as well as the presumed etiology of the qualifying event. Silent infarction was defined as a focal hypodensity on brain CT, not related to the recent ischemic event. The overall prevalence was 33% (102/306) with a higher rate in stroke patients (83/225, 37%) than in TIA patients (19/81, 23%; p = 0.028). Age (p < 0.01), smoking (p < 0.01), hypertension (p = 0.013), and leukoaraiosis (p = 0.05) were significantly associated with SCI, but only in some degree in TIA patients. Presence of SCI was statistically associated with a small-artery disease (p < 0.01) considered as the cause of the qualifying event. Emboligenic cardiopathy was significantly more frequent in patients without SCI (p < 0.05) in the TIA subgroup. Thus, in patients with silent cerebral infarcts, small-vessel disease may be in most cases the cause of the recent symptomatic cerebral ischemia.