Association of the ASCO classification with the executive function subscores of the Montreal cognitive assessment in patients with postischemic stroke.

BACKGROUND: The ASCO classification can evaluate the etiology and mechanisms of ischemic stroke more comprehensively and systematically than conventional stroke classification systems such as Trial of Org 10172 in Acute Stroke Treatment (TOAST). Simultaneously, risk factors for cognitive impairment such as arterial sclerosis, leukoaraiosis, and atrial fibrillation can also be gathered and graded using the ASCO classification.

METHODS: Sixty patients with postischemic stroke underwent cognitive testing, including testing by the Japanese version of the Montreal cognitive assessment (MoCA-J) and the mini-mental state examination (MMSE). Ischemic strokes were categorized and graded by the ASCO classification. In this phenotype-based classification, every patient is characterized by the A-S-C-O system (A for Atherosclerosis, S for Small vessel disease, C for Cardiac source, and O for Other cause). Each of the 4 phenotypes is graded 0, 1, 2, or 3, according to severity. The conventional TOAST classification was also applied. Correlations between individual MoCA-J/MMSE scores and the ASCO scores were assessed.

RESULTS: The total score of the ASCO classification significantly correlated with the total scores of MoCA-J and MMSE. This correlation was more apparent in MoCA-J than in MMSE, because MoCA-J scores were normally distributed, whereas MMSE scores were skewed toward the higher end of the range (ceiling effect). Results for individual subtests of MoCA-J and MMSE indicated that cognitive function for visuoexecutive, calculation, abstraction, and remote recall significantly correlated with ASCO score.

CONCLUSIONS: These results suggest that the ASCO phenotypic classification of stroke is useful not only for assessing the etiology of ischemic stroke but also for predicting cognitive decline after ischemic stroke.