In CAA, insoluble Aβ is deposited in the basement membranes of capillary endothelia and as excrescences or Drusen that are smooth and globular, irregular or filamentous.
In CAA associated with Alzheimer's disease, small arteries and arterioles are the most common sites of Aβ amyloid deposition [ 13, 17, 18], but amyloid is also detected in capillaries and in veins at a lower incidence [ 18- 20].
In CAA, Aβ is detected by immunohistochemistry mainly in the tunica media of smaller leptomeningeal arteries but is present in the adventitia on the outer aspects of medium-sized leptomeningeal arteries [ 23], suggesting that Aβ follows the same lymphatic drainage route as tracers in experimental animals [ 7, 9].
In addition, they also display the potential to carry therapeutic agents to reduce cerebrovascular inflammation associated with CAA, which is believed to trigger hemorrhage in CAA patients.
With the use of our previously published method to separately quantify parenchymal amyloid and CAA [ 17, 21], we found a significant decrease in parenchymal amyloid along with a significant concomitant increase in CAA.
The nanocore was also loaded with cyclophosphamide (CYC), an immunosuppressant shown to reduce the cerebrovascular inflammation in CAA.
Another possible mechanism of leukoaraiosis in CAA is as a result of the accumulation of silent ischaemic lesions [3].
The origin of Aβ in CAA is likely to be neuronal, although cerebrovascular cells or the circulation cannot be excluded as a source.
CAA-related impairments of perfusion due to amyloid in the overlying cortical small vessels probably cause the leukoaraiosis in CAA patients [3, 32].
Considering the high prevalence of MBs and SS in CAA patients [24], these abnormal findings should be evaluated in the diagnosis of cSAH.
In the pathological analysis of lobar MBs in CAA patients, various CAA-related pathologies, including acute microhaemorrhages, haemosiderin residua of old haemorrhages and small lacunes ringed by haemosiderin, are proved to produce signal voids on SWI [20].
