Middle cerebral artery stenosis in a Portuguese population: what happened during nearly a decade of follow-up?

Abstract

Background: Intracranial atherosclerotic stenosis is a major cause of stroke, particularly in Asia, but its impact in Caucasian-European populations remains poorly studied. Objectives: To assess the progression of middle cerebral artery (MCA) stenosis in a Portuguese population and its association with cerebrovascular events, cognitive and functional status, vascular risk factors, and available treatments. Methods: A single-center, cross-sectional cohort study with a 9-year retrospective analysis of Portuguese patients with MCA stenosis (>50% luminal narrowing) without extracranial stenosis. Patients with large vessel or diffuse small vessel disease were excluded. Assessments included transcranial Doppler ultrasound, cognitive (MMSE/MoCA), and functional (mRankin scale) evaluations. Results: Among 22 patients, 17 (77.3%) were male, with a mean age of 76 years. Four (18.2%) died, including one (4.5%) from stroke. Of 18 reassessed patients (72.2% male, mean age 74.3 years), two (12.5%) had cerebrovascular events. At baseline, 45.5% had moderate (50-70%) and 54.5% had severe (>70%) stenosis. At follow-up, stenosis worsened in 16.7%, remained stable in 38.9%, and improved in 44.4%, with significant reductions in systolic (-106.4 cm/s) and diastolic (-69.7 cm/s) MCA velocities (p<0.001). Cognitive (MMSE p=0.627; MoCA p=0.326) and functional (p=0.851) status remained unchanged. No association was found between stenosis progression and clinical variables, except for patients on calcium channel blockers (CCB), who more frequently showed stability or improvement (p=0.043). Conclusion: CCB may positively influence MCA stenosis progression, though its clinical relevance remains unclear, as most patients remained stable or improved regardless of functional or cognitive outcomes.