Figure 1.
BASIS and ASPECTS classification.
Patients are classified as BASIS+ if there are proximal cerebral artery occlusions observed on CTA or a significant hypodensities on NCCT. The relevant arterial segment occlusions are depicted in drawing on the left and are defined as including the following arteries: distal (intracranial) internal carotid artery (ICA), proximal (M1 or M2) middle cerebral artery (MCA) and/or basilar artery (BA). If none of these arteries are observed to be occluded on the CTA, then the NCCT is scored using the scheme shown on the right for anterior circulation strokes, which is also used for ASPECTS scoring. If a hypodensity deemed to be consistent with acute ischemic infarction is identified in one of the cerebral regions shown, a point is deducted from the maximum score of 10. Patients with scores of 7 or less are both BASIS+ and ASPECTS+. BASIS+ classification for posterior circulation strokes in the absence of basilar artery occlusion requires bilateral pons or bilateral thalamus hypodensities.
Table 1.
Demographics, comorbidities, and treatment.
Table 2.
Prediction of poor outcome.
Figure 2.
Patient outcomes by NIHSS/BASIS classification.
Patient outcomes, regardless of treatment, are grouped into possible combinations of BASIS and NIHSS. There are significant differences in outcomes amongst the categories (3×2 contingency table p<0.0001). Both the NIHSS≤10/BASIS− and the NIHSS>10/BASIS+ groups are significantly different from each other and from the other categories (****, p<0.0001).