Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephaloapthy (CADASIL): a hereditary cerebrovascular disease, which can be diagnosed by skin biopsy electron microscopy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebrovascular disease characterized by recurrent subcortical ischemic strokes starting in the third or fourth decade as a result of mutations in the Notch3 gene. Granular osmiophilic material (GOM) deposition around the vascular smooth muscle cells is a specific feature and electron microscopic observations of skin biopsies are useful for this diagnosis. A 39-year-old female with dizziness, abnormal visual fields, and hemiplegia, and a 42-year-old male with tinnitus and dizziness, were suspected of suffering from CADASIL based on MRI findings. Both cases were shown to have characteristic deposits of GOM, 200 to 800 nm in diameter, around the vascular smooth muscle cells of small arteries in the deep dermis, and thus the diagnoses of CADASIL were made, although there was no family history of cerebrovascular disorders or dementia. Dermatologists should be aware of these ultra-structural findings because this disease may occur sporadically and might be more common than initially thought.