To report bilateral confluent T2 hyperintensities in medial temporal lobes on brain magnetic resonance imaging (MRI) in a patient with newly diagnosed cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Literature search to date did not report T2/FLAIR hyperintensities in medial temporal lobes on brain MRI in CADASIL.

Case report: A 58-year-old woman with lifelong complex migraine headaches, scleroderma and family history of suspected degenerative dementia, presented to emergency department with one-week history of intractable complicated migraines. Brain MRI disclosed extensive, confluent T2/FLAIR white matter disease, including the bilateral medial temporal lobes but acute stroke on diffusion weighted imaging (DWI).

Genetic testing confirmed CADASIL with a positive notch 3 c.3062A>G; p. Tyr1021Cys heterozygous missense mutation, pathogenic and autosomal dominant. A panel for vanishing demyelinating disorders was negative. Lumbar puncture was negative for multiple sclerosis, acute meningitis, encephalitis or active vasculitis but positive for mild nonspecific hyperactive IgG in cerebrospinal fluid (CSF) in this patient with also chronic scleroderma. A comparison with prior brain MRIs revealed progression of the white matter disease over years, comprising also T2 bilateral medial temporal lobe hyperintensities.

Bilateral medial temporal lobe T2/FLAIR hyperintensities in this patient with newly diagnosed CADASIL embodies a novel neuroimaging pattern in CADASIL. This highlights the benefit for CADASIL testing even in patients with only partial clinical features in association with extensive white matter disease. A correlation between progression of white matter disease, activity of Ig G, other CSF markers and co-morbidities in patients with CADASIL is scarcely known and can be studied further.