Clinical aspects of cerebral amyloid angiopathy.

Amyloid depositions mainly consist of proteins with a fibrillary structure. A large number of different proteins have amyloidogenic properties. Amyloids are now categorized on the basis of their chemical structure, but the clinical classification of localized and systemic amyloid is still useful. The proteins that can be found in cerebral amyloid angiopathy are cystatin C, beta/A4 and transthyretin. Cerebral amyloid angiopathy can remain symptom-free, but can also give a broad spectrum of clinical and radiological manifestations, including (vascular) dementia, cerebellar and cerebral hemorrhage, subarachnoid hemorrhage, and leukoencephalopathy. It is debated whether amyloid angiopathy plays a causative role in Alzheimer's disease, but it is strongly correlated with the presence of cerebral plaques. In this review, the clinical spectrum of cerebral amyloid angiopathy will be described, based on retrospective studies from the literature. Hereditary cerebral hemorrhage with amyloidosis (Dutch) will be presented as a 'prospective' model to study the clinical effects of amyloid angiopathy.