Nevertheless, a recent study revealed that stroke patients with lacunar infarcts may also benefit from pharmacological reperfusion. However, they did not show clinically significant differences between the collateral flow patterns. used CT perfusion to demonstrate that there was delayed compensatory collateral supply in recent SSI. first observed anterograde and retrograde collaterals in acute lacunar infarction using 4D dynamic susceptibility contrast (DSC) MR perfusion. If we assume the hypothesis is valid, collateral circulation may be observed and plays a critical role in maintaining perfusion in the penumbral region of acute SSI.įorster et al. Nevertheless, it is questionable whether the penumbra hypothesis could be applied in the microcirculation. Small perfusion defects were observed in computed tomography (CT) and magnetic resonance imaging (MRI) perfusion studies and they were shown to be associated with the development of early neurological deterioration (END), and interpreted as indicating the existence of penumbra. However, previous studies of postmortem human brain revealed anastomoses of the major perforators and precapillary arterioles. In the past, lacunar infarction was thought to be caused by the occlusion of a terminal penetrating artery, without collateral circulation and the occurrence of penumbra. BAD is caused by occlusion or stenosis at the origin of the large caliber penetrating arteries due to microatheromas or junctional plaques. However, there are other pathologies including embolism, microatheroma, and branch atheromatous disease (BAD). Recent SSIs are associated with the occlusion of penetrating arteries from different pathologies of SVD, including cerebral amyloid angiopathy and hypertensive arteriopathy. Further studies are warranted to verify these findings and to investigate effective treatments.Ĭlinically evident recent small subcortical infarctions (SSI), commonly called lacunar infarcts, account for around one quarter of all cases of ischemic stroke and are also one of the neuroimaging features of small vessel disease (SVD). Both anterograde and retrograde collaterals may play a critical role in maintaining cerebral perfusion and can have an impact on patient clinical outcomes. 1.34 ml, p = 0.031), and a higher rate of lobar cerebral microbleeds (30 vs. 21% p = 0.028), whereas retrograde collaterals were associated with higher systolic and diastolic blood pressure ( p = 0.031 and 0.020), smaller initial infarction volume (0.81 vs. 0.77 p = 0.024) and a higher rate of deep cerebral microbleeds (48 vs. The anterograde collaterals were associated with higher relative cerebral blood volume (0.91 vs. Patients with hypoperfusion pattern had the highest rate of early neurological deterioration (32%, p = 0.007), the largest initial and final infarction volumes ( p < 0.001 and p = 0.029), the lowest relative cerebral blood flow (0.63, p < 0.001), and the lowest rate of anterograde and retrograde collaterals (19%, p < 0.001 66%, p = 0.002).
The development of anterograde or retrograde collaterals was also evaluated. Using 4D dynamic perfusion MRI, they were divided into three patterns: 25 (24%) with normal perfusion, 31 (30%) with compensated perfusion, and 47 (46%) with hypoperfusion. A total of 103 patients with acute SSI in penetrating artery territories were recruited and underwent MRI within 24 h of stroke onset. We evaluate the hemodynamic changes and collaterals in acute SSI using perfusion magnetic resonance imaging (MRI). The hemodynamic changes of acute small subcortical infarction (SSI) are not well understood.