Ischemic events are a recognized complication of flow diversion stents (FDS) in middle cerebral artery (MCA) aneurysms, often related to branch or perforator coverage. However, the clinical significance of isolated lenticulostriate artery territory infarcts following FDS remains incompletely understood.

We retrospectively reviewed consecutive patients treated with FDS for MCA aneurysms between January 2013 and December 2024. Baseline demographics, vascular risk factors, aneurysm and procedural characteristics were collected. Functional outcomes were assessed by the modified Rankin Scale (mRS) at discharge and at 6 months. All patients underwent magnetic resonance imaging (MRI) within 24–48 hours after treatment.

Forty-two patients were included (69% women; mean age 55.1 years). Diffusion-weighted imaging identified ischemic lesions in 6 patients (14.2%), exclusively within the lenticulostriate artery territory; 4 were clinically silent, and 2 patients (4.8%) had an mRS ≥ 2 at discharge. Ischemic lesions were significantly associated with diabetes mellitus (χ² = 19.385, p < 0.001) and dyslipidemia (χ² = 5.933, p = 0.015). No significant associations were observed with hypertension, smoking status, antiplatelet regimen, device type, or device size. Higher stent-to-vessel diameter ratios showed a non-significant trend toward lower odds of perforator territory ischemia.

In this single-center study, flow diversion for MCA aneurysms was associated with a measurable rate of lenticulostriate territory ischemia, most of which was clinically silent. The strong associations with metabolic comorbidities and the observed influence of device–vessel relationships highlight the importance of patient selection and vascular risk factor optimization. Prospective studies with standardized imaging and neurocognitive follow-up are warranted to clarify the long-term significance of asymptomatic ischemic lesions.