Early Tc-99m-ethylcysteinate dimer brain SPECT patterns in the acute phaseof stroke as predictors of neurological recovery

Objectives: Accurate prediction of outcome in acute stroke would help in id entifying subgroups of patients for therapeutic trials and intravenous thro mbolysis. The purpose of this study was to prospectively test the hypothesi s that brain SPECT, with Tc-99m-L,L-ethylcysteinate dimer (ECD), a tracer s ensitive to cell function, performed in the first hours after stroke onset, adds predictive power to concomitant neurological evaluation. Methods: Twe nty-four patients with a first-ever middle cerebral artery stroke were pros pectively studied with ECD-SPECT within 12 h after stroke onset. Neurologic al evaluation was performed using Orgogozo's scale at admission and 3 month s later in order to calculate the percent Martinet-Vila evolution indices ( EI%). Semiquantitative visual analysis of SPECT images was performed in 6 c ortical regions relevant for carotid artery territory. Both the extent and the intensity of cortical reduced ECD uptake were calculated, leading to an 'ischemia' score, corresponding to the sum of regions of interest (ROI) wh ere ECD uptake was between 40 and 80% of the contralateral healthy hemisphe re, and an 'irreversibly damaged tissue' (IDT) score, corresponding to an u ptake below 40%, and a total score (ischemia + IDT). Each patient was assig ned to one of three patterns: (1) pattern I with severe ECD cortical uptake reduction defined by at least one ROI with uptake under 40%, (2) pat tern II with moderate ECD cortical uptake reduction (40-80%) only and (3) patter n III with normal ECD uptake. Results: There were 11 patients (46%) with pa ttern I ECD-SPECT. This group had almost invariably(10/11 patients) a poor outcome. The 12 patients (50%) classified in pattern ii had a variable clin ical outcome, ranging from improvement to deterioration. The single patient with a normal SPECT (pattern III) had a full clinical recovery. Both total score and IDT sco re were strong ly significantly correlated with neurolog ical recovery EI% (respectively p = 0.006 and 0.004). Their predictive valu e was significantly higher than, and independent of, day 0 neurological eva luation. No patient had an increased ECD uptake. Conclusion: Our results sh ow that the degree of ECD cortical uptake reduction, measured on early brai n SPECT, is a strong predictor of neurological recovery. ECD-SPECT data hav e a higher predictive value than day 0 neurological evaluation. The apparen tly better predictive value of ECD over hexamethylpropyleneamine oxime may reflect this tracer's brain retention mechanisms which are weighted more to wards cell function than towards perfusion. ECD-SPECT is easily obtainable and may help in selecting out from therapy those patients who are likely to have either very good or very poor spontaneous outcome, and thus improve t he assessment of acute stroke and the choice of therapeutic strategy. Copyr ight (C) 2000 S. Karger AG, Basel.