Features of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy.

Abstract

The cerebral small vessel system plays a fundamental role in maintaining higher brain function.1 Although lacunar stroke has been recognized as a disease in which small vessels are mainly affected, advances in neuroradiological examination extend our knowledge of small vessel disease to white matter lesions, microbleeds, and cortical microinfarction.2 Accumulating evidence indicates that the risk factors and the therapeutic strategies are different for large vessel disease and small vessel disease.3 Moreover, the recent discoveries on monogenic disorders, which mainly affect small vessels, clearly indicate that the human cerebral small vessels have distinct molecular characteristics of cerebral large vessels.4 However, little is known about the molecular pathogenesis of small vessel disease and how it is different from that of large vessel disease. The investigation of hereditary small vessel disease is necessary to clarify the molecular pathogenesis of cerebral small vessel disease (CSVD). Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is the most common dominant inherited CSVD, whereas cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a rare form of inherited CSVD.5,6 Fukutake6,7 has proposed the clinical triad for CARASIL, leukoencephalopathy, alopecia, and lumbago and has summarized the clinical findings of CARASIL in these patients. The identification of the causative gene for CARASIL allows a new understanding of the molecular pathogenesis of CSVD.5 Although CARASIL has been considered to be restricted to Japan, we now know that CARASIL exists in other populations. In this review, we update the clinical findings of CARASIL confirmed by genetic analysis and molecular pathogenesis of CARASIL. In 1976, Maeda et al8 reported familial unusual encephalopathy of the Binswanger’s type without hypertension in siblings whose parents were consanguineous. They showed early adult-onset dementia, pseudobulbar palsy, and pyramidal and extrapyramidal symptoms. Postmortem …