Cerebral Small Vessel Disease: Bystander or Culprit?

Cerebral small vessel disease (SVD) contributes to about 45% of dementias and causes substantial cognitive, psychiatric, and physical disability. The most common form of monogenic strokes is cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which is caused by mutations in the NOTCH3 gene. This leads to cerebrovascular NOTCH3 protein aggregation and compromises cerebral blood flow. We present the case of a 69-year-old female patient presenting with dysarthria, a past medical history of migraines, and a family history of early-onset stroke. She was treated at a large district general hospital. Non-contrast computed tomography (CT) brain showed changes in keeping with small vessel ischaemic change. Subsequent magnetic resonance imaging (MRI) revealed an acute right frontal lobe infarct with extensive high signal intensity changes. Involvement of the temporal lobes suggested CADASIL as a possible differential diagnosis. The genetic testing confirmed a heterozygous pathogenic NOTCH3 variant. This case highlights the importance of testing for CADASIL in patients with extensive SVD changes coupled with a history of stroke at an early age or family history of strokes. Informed written consent was obtained from the patient to publish her clinical information anonymously.