Clinical outcome based on central vs. peripheral ASPECTS regions in evaluation of acute ischemic stroke

The aim of the study is to analyse clinical outcome based on whether central or peripheral regions are affected according to Alberts Stroke Programme Early CT Score (ASPECTS) division. A retrospective analysis of 51 patients with acute middle cerebral artery ischemic stroke was done. Patient evaluation was done by using NIHSS scale (The National Institutes of Health Stroke Scale) and non-contrast CT scan was done at the time of admission and on follow-up after 24 to 48 hours. ASPECTS value was measured for each CT scan. Patients were divided in two groups based on the affected ASPECTS region- central lesions (Nucleus caudatus, Nucleus lentiformis, Capsula interna, Insula) and peripheral lesions (M1- M6). The mean ASPECTS score of initial CT scan in central lesion group was 9.452±1.090 and in peripheral lesion group 9.750±0.638; follow-up scan mean ASPECTS score in in central lesion group was 7.000±1.291 and in peripheral lesion group 8.200±1.239. NIHSS scores were higher at the admission and on follow-up in patients that had central regions affected comparing to patients with no central regions affected - initial mean NIHSS scores in central lesion group was 12.290±4.755 and in peripheral lesion group 7.750±6.068; follow-up mean NIHSS scores in central lesion group was 6.097±4.206 and in peripheral lesion group was 3.400 ± 2.927. NIHSS score differences between groups were statistically significant on initial evaluation (Mann-Whitney U test, n= 51, u= 139.500, p<0.01) and on follow-up (Mann-Whitney U test, n= 51, u= 182.000, p<0.02). It is important to analyse affected ASPECTS regions by taking into account that centrally located regions have higher impact on sustaining brain connectivity. Relaying on ASPECTS value alone can lead to unjustified prediction of clinical outcome. Furthermore, stroke occurring in peripheral regions demonstrates the same ASPECTS value as stroke in central regions, but the clinical outcome prognosis could differ significantly.