Background and Purpose-Small infarcts in the territory of penetrator arteri
es were described as causing a number of distinct clinical syndromes. The v
ascular pathophysiology underlying such infarcts is difficult to ascertain
without careful pathological study. However, the occurrence of multiple, sm
all infarcts, linked closely in time but dispersed widely in the brain, rai
ses the possibility of an embolic mechanism. The current study determines t
he frequency and clinical characteristics of patients with well-defined lac
unar syndromes and the diffusion-weighted imaging (DWI) evidence of multipl
e acute lesions.
Methods-Sixty-two consecutive patients who presented to the emergency room
with a clinically well-defined lacunar syndrome were studied by DWI within
the first 3 days of admission.
Results-DWI showed multiple regions of increased signal intensity in 10 pat
ients (16%). A hemispheric or brain stem Index lesion") was found in all. l
esion in a penetrator territory that accounted for the clinical syndrome ("
DWI-hyperintense lesions other than the index lesion ("subsidiary infarcti
ons") were punctate and lay within leptomeningeal artery territories in the
majority. As opposed to patients with a single lacunar infarction, patient
s with a subsidiary infarction more frequently (P<0.05) harbored an identif
iable cause of stroke.
Conclusions-Almost 1 of every 6 patients presenting with a classic lacunar
syndrome has multiple infarctions demonstrated on DWI, This DWT finding usu
ally indicates an identifiable cause of stroke and therefore may influence
clinical decisions regarding the extent of etiologic investigations and tre
atment for secondary prevention.