[Diagnosis, pathomechanism and treatment of CADASIL]

During the past 10 years, our understanding of the pathomechanism and pathophysiology of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) has improved through clinical examination, imaging studies, pathological studies, cell experiments and the development of transgenic mice. Although epidemiological studies of CADASIL in Japan have been limited, more than 100 cases of this condition have been diagnosed in Japan. In our laboratory, we diagnosed 37 CADASIL cases genetically and identified three features common to Japanese cases. One is the wide distribution of onset age for clinical symptoms other than migraine, with the onset of symptoms being later than age 60 in 22% of cases. Second, the majority (65%) of Japanese CADASIL cases have stroke risk factors, such as hypertension, hyperlipidemia, or smoking. Third, in 22% cases there was no definite family history of stroke. However, the previous diagnostic criteria proposed by Dabous excluded several definite cases in our cohort. Therefore, to avoid missing undiagnosed cases of CADASIL, we have generated new diagnostic criteria for Japanese CADASIL based on the knowledge accumulated during the past 10 years, and compared sensitivity of two criteria. In our diagnosed Japanese CADASIL cases, the sensitivity of the new criteria was 19% and 78% for probable and possible cases, respectively, and only one case was (Fig. 3) missed when using the new criteria. In comparison, the sensitivity of Dabous's was 11% and 51% for probable and possible cases, respectively, and 24% cases were excluded due to hypertension, elderly onset or no family history, although these cases showed recurrent strokes, white matter lesions and NOTCH3 mutations. Using our new criteria, diagnosis of CADASIL can be made even in cases with elderly onset, stroke risk factors, and obscure family history.