includes ICAD-related stroke made when a smooth-bordered lesions leading to delayed perfusion on conventional-angiography (without competing stroke etiology) or when irregular-surfaced lesions involving the target vessel during mechanical thrombectomy were unveiled (with or without competing stroke etiology).

Non-ICAD cases (controls) includes patients with posterior circulation stroke attributed to stroke etiologies other than ICAD.

We are aiming to develop a Scoring system based on certain variables derived from both group

sICH is defined as local or remote parenchymal hemorrhage type 2, subarachnoid hemorrhage, and/or intraventricular hemorrhage, combined with a neurological deterioration of 4 points or more on the NIHSS from baseline or leading to death that the physician judged was causative of the deterioration) per ECASS III criteria

a score of 0 to 4 on the modified Rankin scale (range, 0 to 6, with a score of 0 indicating no disability, 4 moderately severe disability, and 6 death) at 90 days, was changed to a good functional status (a modified Rankin scale score of 0 to 3, with a score of 3 indicating moderate disability)