[Young-adult-onset hereditary subcortical vascular dementia: cerebral autosomal recessive arteriosclerosis with subcortical infarcts and leukoencephalopathy (CARASIL)].

The clinical features of a probably autosomal recessive syndrome ("CARASIL"), yet to be confined in Japan and characterized by prematurity of vascular dementia, alopecia and spondylosis deformans are reviewed through comparison with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which has been reported in Europe and North America, and recently in Japan. These two syndromes have many common features, such as familiality, encephalopathy of Binswanger type, and absence of vascular risk factors. There exists, however, a number of differences as follows: (1) Onset of encephalopathy is 32 years of age in "CARASIL" vs. 45 in CADASIL. (2) Male to female ratio is 3.2: 1 vs. 2:1.(3) Two thirds of "CARASIL" patients show stroke and/or stepwise deterioration, while almost all CADASIL patients have stroke. (4) Associated psychiatric features are euphoria, emotional lability and loss of spontaneity vs. severe mood disorders. (5) Migraine is a cardinal feature of CADASIL and vasospasm may occur during cerebral angiography. (6) White matter lesions on MRI are diffuse and homogeneous vs. punctuated and nodular. The latter four differences may mirror the difference in the pathology of arteriopathies. "CARASIL" is clearly different from CADASIL and reflect a second genetic condition with a seemingly direct effect upon the cerebral vasculature.