Relationship between cerebral blood flow and clinical outcome in acute stroke

The purpose of this study was to determine the relationship between cerebral blood flow (CBF) measurements in acute stroke and early clinical outcome.

The xenon-enhanced computed tomography (XeCT) CBF studies performed in 50 patients in the acute stage (within 8 h) of a hemispheric stroke were retrospectively analyzed. The mean CBF of the symptomatic vascular territory was compared to the corresponding territory in the contralateral hemisphere. Clinical assessment on admission and discharge was performed using the National Institutes of Health stroke scale (NIHSS).

Three groups were defined according to the degree of CBF asymmetry between the symptomatic and the contralateral asymptomatic vascular region. The CBF asymmetry was mild in group A (< or =20%), moderate in group B (>20% and <60%) and severe in group C (> or =60%). Patients in group A (n = 18) had a good outcome with a mean NIHSS score of 2 +/- 2 at discharge. In group B, the patients (n = 22) had intermediate but variable outcomes: 2 patients died and the mean NIHSS score for the survivors was variable (mean NIHSS score: 9 +/- 6). The patients in group C (n = 10) had a very poor outcome: 4 patients died and the survivors had a mean NIHSS score of 15 +/- 1.

Quantitative XeCT CBF measurements may be useful for selecting subgroups of stroke patients with different clinical outcomes. The possibility of predicting patient prognosis as early as in the first hours after the ischemic event may help to identify the appropriate target population that will benefit from aggressive stroke therapy.