Rangaraju S, Streib C, Aghaebrahim A, Jadhav A, Frankel M, and Jovin TG. Relationship Between Lesion Topology and Clinical Outcome in Anterior Circulation Large Vessel Occlusions. Stroke. 2015
We use the ASPECT score in my hospital prior to deciding on whether or not a patient is likely to have a good outcome from endovascular thrombectomy. It is used because it is simple. We look at the imaging, and count areas of involvement. The cortical areas are broken up into 7 parts with a point each, and the sub-cortex is broken up into 3 parts, each one of those gets a point: http://www.aspectsinstroke.com/aspects/what-is-aspects/
If the ASPECT score is less than 7, we tend to get a little hesitant about taking the added risk of endovascular therapy. But, that is because we assume that every point on the ASPECT score is created equal. But, are they? That is essentially the question that Dr. Rangaraju and his colleagues aimed to answer in this recently published study.
They used the DWI ASPECTS, which is the MRI cousin of the original ASPECT. The locations are the same. All the patients in this study had either, ICA, M2 or M2 MCA occlusions and were treated with endovascular therapy. There were 213 patients in the study. Their DWI ASPECTS were evaluated within 12-72 hours after thrombectomy, and multivariable logistic regression was used to determine the correlation between the 10 DWI ASPECTS locations and outcome based on the 90-day mRS. The reason they used post-treatment imaging, they argued, was because the pre-treatment ASPECTS may be misleading since the eventual infarct may be significantly different than the first impression on a CT scan due to variation in time to recanalization of the occluded vessel.
The study was well designed, and although the patients were extracted from a prospective endovascular registry, the DWI ASPECTS was calculated retrospectively. There were a few other limitations of the study, but the findings are interesting and probably representative of “real-life” scenarios.
The conclusion of this study suggested that if the left M4 region (superior frontal) or the right M6 region (superior parietal) were involved on the DWI ASPECTS, then the patient was significantly more likely to have a poor outcome after endovascular treatment. Destruction of the left M4 and right M6 territories correspond to aphasia and hemineglect, respectively. It made sense that these two areas should carry more weight with regard to outcome since their effects on independence and function are potentially profound.