Contralateral hemispheric cerebral blood flow can predict short-term clinical outcomes in patients with recent small subcortical infarcts.

Background: The potential association between contralateral hemispheric cerebral blood flow (CBF) and short-term clinical outcomes of recent small subcortical infarcts (RSSIs) remains unclear. Arterial spin labeling (ASL) can quantify CBF noninvasively. This study aimed to investigate the relationship between contralateral hemispheric CBF and 3-month outcome in patients with RSSIs using ASL.

Methods: Consecutive patients with a diagnosis of RSSIs were recruited. All enrolled participants underwent ASL examination with post-labeling delay (PLD) of 1.5 and 2.5s. Hemispheric CBF values and the ratios of CBF between the affected and unaffected hemispheres were calculated for both PLDs. The 90-day modified Rankin Scale (mRS) was used to evaluate the functional outcome, with patients classified into good (mRS 0-1) and poor (mRS 2-6) outcome groups. Univariate and multivariable logistic regression were conducted to evaluate the association between contralateral hemispheric CBF and mRS at 90 days after RSSIs.

Results: 105 patients (62.4 ± 13.1years; 73 men) were included in this study. 71 patients (67.6%) showed favorable 90-day clinical outcomes. Patients with favorable outcomes exhibited lower baseline NIHSS (P<0.001), smaller lesion volume (P = 0.028), smaller white matter hyperintensities volume (P = 0.041) and higher contralateral CBF at both PLDs (P<0.001) compared to those with poor outcomes. After adjusting for significant factors identified in inter-group comparisons and univariate analysis, higher contralateral CBF was an independently predictive factor of an excellent clinical outcome at 90 days, both at 1.5s PLD (OR = 0.861, P = 0.001) and 2.5s PLD (OR = 0.877, P = 0.004).

Conclusions: Contralateral hemispheric CBF is independently associated with 3-month outcomes in RSSI patients.