Paraproteinosis and amyloidosis of the cerebral vessels and senile plaques

Blood-brain barrier in Alzheimer dementia and in non-demented elderly. An immunocytochemical study

Peroxidase-antiperoxidase staining of formalin-fixed brain was employed to compare the blood-brain barrier (BBB) function in five patients with Alzheimer's disease/senile dementia of the Alzheimer type (AD/SDAT) and three patients with AD/SDAT combined with multi-infarct dementia (MID/SDAT) with that of six non-demented aged controls. The diffusion of serum proteins through the BBB was visualized with antisera to albumin, prealbumin, immunoglobulin, C1q, C3c and to fibrinogen. A similar patterns of diffusion was seen in AD/SDAT and non-demented aged individuals. Neuron and glial cells were stained with different antisera in the vicinity of the diffusion. Senile (neuritic) plaques were occasionally visualized with antisera to IgG, C1q and C3c but not with antisera to albumin, prealbumin and fibrinogen in both demented and non-demented aged individuals. Neurofibrillary tangles were not labelled with any of the antisera studied. These results indicate that the BBB is compromised equally in AD/SDAT and in the non-demented elderly.

Cerebral amyloid angiopathy: incidence and complications in the aging brain. I. Cerebral hemorrhage

The clinical and pathologic findings in eleven patients with fatal cerebral hemorrhages related to cerebral amyloid angiopathy (CAA) are described. The hemorrhages were bihemispheric, though not necessarily of simultaneous onset in four patients, and favoured the fronto-parietal cortex and white matter in ten patients. Dissection into the subarachnoid space was common. Cerebrovascular lesions or cardiomegaly related to hypertension coexisted with those of CAA in three cases. Seven patients were not demented prior to the ictus. Ten of eleven brains contained abundant senile plaques and/or neurofibrillary tangles, whether or not the patient had been clinically demented. In the elderly, CAA is an important etiologic consideration for cerebral hemorrhage, especially if the hemorrhage occurs in a peripheral location in the brain and is superimposed on a history of dementia.

Cerebral amyloid angiopathy

Cerebral amyloid angiopathy is nonspecific disease entity that has been associated with a number of neuropathologic conditions, the most prominent being dementia and cerebral hemorrhage. It occurs more commonly than is generally appreciated, with implications that may be overlooked. Amyloid deposits are found in the vessels of the leptomeninges and cerebral cortex. There is often a close topographic relation to senile plaques, the histologic abnormality characteristic of Alzheimer's disease and senile dementia. Because of this relation and the well documented presence of amyloid in senile plaques, a similar natural history has been postulated for each. Histochemical studies indicate, however, that there are distinct differences between the amyloid deposits in cerebral vessels and senile plaques. An association between cerebral amyloid angiopathy and other forms of amyloidosis has similarly failed to be established, and a successful form of therapy has yet to be devised.