Type:
Educational Exhibit
Keywords:
Hypertension, Haemorrhage, Dementia, Imaging sequences, MR, CT, Neuroradiology brain
Authors:
B. Futácsi, K. Karlinger; Budapest/HU
DOI:
10.1594/ecr2013/C-1839
Background
While cerebral amyloid angiopathy is a relatively common cause of non-traumatic intracerebral hemorrhage in the elderly (12-15% of hemorrhages above the age of 60) [1],
it still remains under-diagnosed.
It is probably because on the one hand CAA only makes up 2% of all ICH [2],
and on the other CAA bleeds lack explicit clinical or imaging features.
However,
certain imaging clues together with the clinical data can be suggestive for CAA.
In the following section we aim to lay out an overview on the ways our understanding of the disease has evolved.
A. History of CAA
1907 Alzheimer - deposition of a “peculiar and difficult to stain” substance in intracranial vessels [1]
1909 Oppenheim – amyl+oid = “starch like” substance.
Falsely believed to be iodine containing fatty- or carbohydrate deposit.
Now known,
amyloid appears in many diseases,
and it is an irregularly folded superoxidized β-structure protein derivate.
/CAA related amyloid is not deposited in extracerebral organs and should not be confused with systemic amyloidosis./
1979 Okazaki – association of dementia and lobar hemorrhage [1]
1990s Boston Diagnostic Criteria - international categorization tool of CAA related hemorrhages
2012 Molecular imaging of Alzheimer’s disease (AD); β-amyloid specific radiopharmaceuticals – (florbetapir F18) might provide future insight for more subtle,
less severe forms of the disease [3]
B.
Pathophysiology
Note: only 40% of CAA patients show AD at autopsy.
The two diseases are overlapping but not directly linked! [2]
C.
Clinical appearance
- intracranial hemorrhage– consequent neurologic deficit
- transient focal neurologic episodes (TIA-like attacks) amyloid spell
- slowly progressing dementia (25-40%) [4]
- rapid neurologic and cognitive impairment
Age related prevalence ( Table 1 )
- age is a very important differential diagnostic factor for CAA related hemorrhage
- incidence rapidly increases over 55 years
- over 70 years CAA is the most common cause of ICH
Interesting to know: despite the seemingly high prevalence,
only a small portion (5.6%) of CAA patients actually develop bleeding! [5]