The Etiology of Intracranial Artery Stenosis in Autoimmune Rheumatic Diseases: An Observational High-Resolution MR Imaging Study

BACKGROUND AND PURPOSE: Autoimmune rheumatic diseases (AIRD) can cause intracranial artery stenosis (ICAS) and lead to stroke. This study aimed to characterize patients with ICAS associated with AIRD.

MATERIALS AND METHODS: Using data from a high-resolution MR imaging database, we retrospectively reviewed patients with AIRD with ICAS. Stratification into vasculitis, atherosclerosis, and mixed atherovasculitis subtypes was based on imaging findings, followed by a comparative analysis of clinical characteristics and outcomes across these subgroups.

RESULTS: Among 139 patients (mean, 45.1 [SD, 17.3] years; 64.7% women), 56 (40.3%) were identified with vasculitis; 57 (41.0%), with atherosclerosis; and 26 (18.7%), with mixed atherovasculitis. The average interval from AIRD onset to high-resolution MRI was 5 years. Patients with vasculitis presented at a younger age of AIRD onset (mean, 34.5 [SD, 19.4] years), nearly 10 years earlier than other groups (P = .010), with a higher artery occlusion incidence (44.6% versus 21.1% and 26.9%, P = .021). Patients with atherosclerosis showed the highest cardiovascular risk factor prevalence (73.7% versus 48.2% and 61.5%, P = .021) but fewer intracranial artery wall enhancement instances (63.2% versus 100% in others, P < .001). The mixed atherovasculitis group, predominantly men (69.2% versus 30.4% and 24.6%, P < .001), exhibited the most arterial involvement (5 arteries per person versus 3 and 2, P = .001). Over an average 21-month follow-up, 23 (17.0%) patients experienced stroke events and 8 (5.9%) died, with the mixed atherovasculitis group facing the highest risk of stroke events (32.0%) and the highest mortality (12.0%).

CONCLUSIONS: Intracranial arteries are injured and lead to heterogeneous disease courses when exposed to AIRD and cardiovascular risk factors. While atherosclerosis acceleration is common, vasculitis may further contribute to the early development of occlusion and multiple artery involvement. Varied intracranial arteriopathies may result in different outcomes.