A 42-year-old woman with a 15-year history of migraine with aura presents with acute confusion and left-sided weakness. MRI shows a new right-sided lacunar infarct, extensive periventricular white matter hyperintensities, and prominent signal changes in the anterior temporal lobes bilaterally. Her 70-year-old mother has vascular dementia. NOTCH3 sequencing reveals a cysteine-altering variant in exon 4 (EGF-r domain). Her neurologist considers starting anticoagulation for secondary stroke prevention. Is this appropriate?