Skin biopsy findings and results of neuropsychological testing in the first confirmed cases of CADASIL in Norway

Abstract
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is characterized by mutations in the notch3 gene. The mutation can be demonstrated by a gene test. The first group of Norwegian patients with CADASIL confirmed by gene testing was recently described. The present study includes six of the original nine patients with demonstrated notch3 mutation plus one patient with symptoms, who had been unwilling to go through gene testing. These seven patients underwent skin biopsy for electron microscopy. One patient was cognitively too impaired, but six went through neuropsychological testing. By electron microscopy characteristic granular osmiophilic material (GOM) was detected in all skin biopsies. The material is seen as granular deposits in the basal lamina of the smooth muscle layer, often making impressions upon adjacent smooth muscle cells. It seems important that blood vessels over a certain size (diameter >20 microm) are examined. A varying extent of cognitive decline was noted amongst all by neuropsychological testing. In cases with multiple infarctions reduction of perceptual speed, visuospatial skills and working memory could be demonstrated. Four patients showed executive dysfunction.