[Cadasil and other hereditary small vessel diseases of the brain--increasingly diagnosed conditions underlying familial ischaemic stroke and dementia].

: CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) has recently gained great interest in vascular neurology as the most common heritable cause of stroke and vascular dementia in adults. This autosomal dominant small vessel disease of the brain--unlike the sporadic, hypertensive form--appears already in adult midlife in the absence of vascular risk factors with ischemic episodes and progressive dementia, its first manifestation can be migraine with aura, and is often associated with psychiatric disturbances. The magnetic resonance imaging (MRI) changes showing a characteristic pattern may precede symptoms by more than a decade. The identification of the mutation of the NOTCH 3 gene responsible for the disorder encoding a transmembrane receptor of vascular smooth muscle cells - has given great impetus on research to understand the molecular and vascular pathogenesis of the disease. The special importance of this latter lies in the fact that CADASIL provides a pure genetic model for subcortical cerebral ischemia and vascular dementia without the confounding factors of comorbidities and advanced age. Thus insights into CADASIL may help us better understand the more common sporadic forms as well. Moreover CADASIL is one of the best studied examples of secondary migraine. Currently we have far less knowledge on other forms of hereditary small vessel disease of the brain such as CARASIL, HERNS, CRV, HVR, PXE etc. Neurologists are becoming more and more familiar with CADASIL, and with the wider availability of MRI it is increasingly diagnosed. However the disorder is still probably underrecognised. This review aims to summarize our current knowledge on CADASIL with special emphasis on diagnostic and differential diagnostic points for the practising neurologist.