- NIHSS ≥ 10* or any NIHSS with an intracranial clot should be demonstrated on neurovascular imaging (TCD or CTA) in any one of the following areas: distal internal carotid artery (ICA) carotid artery (CA), middle cerebral artery (MCA - M1 or M2), posterior cerebral artery (PCA - P1 or P2), distal vertebral or basilar artery.