Discussion 
We present a case of acute ischemic stroke associated with neurosarcoidosis [4]. The stroke’s location pointed to a small-vessel disease mechanism. Although the patient had risk factors such as hypertension and polycythemia, the close proximity of the ischemic lesions to areas of previous leptomeningeal enhancement on MRI supports the hypothesis that the ischemic events were secondary to neurosarcoidosis.
Over the past decade, numerous case reports have described acute ischemic stroke as a rare but important complication of neurosarcoidosis [5,6]. Small-vessel vasculitis is the most common ischemic subtype in these cases, with pontine perforating vessels and lenticulostriate arteries frequently affected. These infarcts tend to be small, often involving the basal ganglia, thalamus, and brainstem [8], while rostral supratentorial vessels are less frequently involved [5]. Post-mortem studies indicate that granulomatous vasculitis primarily targets small vessels, particularly perforating arteries [3,8]. Veins, especially in the periventricular region, may also be involved [9]. Histological findings often show granulomas extending along Virchow-Robin spaces in a perivascular distribution, suggesting mechanisms such as vessel compression or direct arterial wall involvement as contributors to ischemia [10,11].
The mechanisms underlying stroke in neurosarcoidosis are diverse and multifactorial. While large-vessel strokes are rare, they may result from inflammation-induced thrombosis, characterized by non-circumferential vessel wall involvement, or compression from adjacent granulomatous lesions [7]. A Moyamoya-like vasculopathy, unilateral or bilateral, has also been reported [12]. Cardioembolic strokes secondary to cardiac sarcoidosis are less frequent [13]. Hemorrhagic lesions, although uncommon, are clinically significant and may arise from inflammatory vascular damage or anticoagulant use. In some cases, extensive thrombosis involving dual sinuses causes venous outflow obstruction, further contributing to ischemic or hemorrhagic complications. These findings underscore the complex interplay of vascular and inflammatory processes in stroke associated with neurosarcoidosis.
The treatment of ischemic stroke in neurosarcoidosis consists of two key components: managing the stroke itself and addressing the underlying sarcoidosis. For stroke management, antiplatelet monotherapy [14] and lipid-lowering agents [15] are commonly employed for secondary stroke prevention. In treating the inflammation associated with neurosarcoidosis, glucocorticoids remain the first-line therapy, often yielding rapid improvements [16]. Severe cases may require pulse-dose intravenous methylprednisolone (1000 mg daily for 3–5 days), followed by maintenance therapy with oral prednisone (60–80 mg daily). To reduce the risk of stroke recurrence, long-term maintenance with steroid-sparing immunosuppressants is often necessary [17, 18]. Monotherapy with agents such as methotrexate or mycophenolate mofetil has generally been insufficient to achieve remission, with most patients requiring at least two lines of immunosuppression. TNF-alpha inhibitors, particularly infliximab, have demonstrated the highest efficacy in achieving remission. However, infliximab use is associated with challenges, including side effects such as chondritis, infusion reactions related to anti-drug antibodies, and potential drug discontinuation. Relapses have also been reported in patients tapered off infliximab, underscoring the complexity of treatment.
Key clinical messageNeurosarcoidosis can present as ischemic stroke through small-vessel vasculitis, requiring early recognition and targeted immunosuppressive therapy to prevent severe disability.
Author contribution statement   Dr. Suppakitjanusant (Corresponding Author): Conceptualization, Methodology, Project Administration, Visualization, Writing – Original Draft, Writing – Review & Editing. Dr. Srifuengfung: Data Curation, Formal Analysis, Supervision, Visualization, Writing – Review & Editing.Dr. Chaisrimaneepan: Conceptualization, Data Curation, Resources, Supervision, Writing – Review & Editing. Dr. Avila: Conceptualization, Data Curation, Supervision, Writing – Review & Editing.All authors have reviewed and approved the final version of the manuscript.