Silent infarcts in stroke patients:: patient characteristics and effect on 2-year outcome

Although silent infarcts (SIs) are frequent in stroke patients, their clinical significance remains controversial, and their effect on stroke outcome remains unclear. This study evaluated the prevalence of SI on computed tomography, associated factors, and the effect on outcome in stroke patients. We studied 202 consecutive patients admitted for acute ischaemic or haemorrhagic stroke with clinical deficits lasting more than 24 h. Survivors were followed up for 24 months; no patient was lost to follow-up. Patients with Rankin scores of 2 or lower were considered separately. New vascular events were also recorded. Computed tomography showed that one-fourth of patients (52/202) had at least one SI; these were located in deep hemispheric areas in 46 patients, superficial hemispheric areas in 5, and the posterior fossa in 7. Logistic regression analysis showed the factors independently associated with SI to be severe leukoaraiosis (OR 1.71, 95% CI 1.26-2.31) and small-vessel occlusion as presumed cause of the index stroke (OR 2.66, 95% CI 1.22-5.79). SI did not affect vital or functional outcome or the occurrence of new vascular events within 2 years after stroke. Whether they affect cognitive outcome remains under evaluation over a longer follow-up period.