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{{Short description|Disease of blood vessels of the brain}}

factoids

| image = Cerebral amyloid angiopathy - very high mag.jpg| caption = Micrograph of cerebral amyloid angiopathy using congo red stain| pronounce =| field =| symptoms =| complications =| onset =| duration =| types =| causes = Cause of CAA is unknown| risks =| diagnosis = PET scan, CT scan| differential =| prevention =| treatment = Management can be physical, occupational, or speech therapy.| medication =| prognosis =| frequency =| deaths =}}Cerebral amyloid angiopathy (CAA) is a form of angiopathy in which amyloid beta peptide deposits in the walls of small to medium blood vessels of the central nervous system and meninges.WEB, Cerebral amyloid angiopathy: MedlinePlus Medical Encyclopedia,weblink www.nlm.nih.gov, 2015-05-27, WEB,weblink UpToDate, www.uptodate.com, 2019-08-17, The term congophilic is sometimes used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after staining with Congo red. The amyloid material is only found in the brain and as such the disease is not related to other forms of amyloidosis.BOOK, Companion to Clinical Neurology,weblink Oxford University Press, USA, 2009-05-06, 9780199710041, FRCP William Pryse-Phillips MD, FRCP(C) Faculty of Medicine Health Sciences Centre Memorial University of Newfoundland St John's, Newfoundland,

Signs and symptoms

CAA is associated with brain hemorrhages, particularly microhemorrhages. The accumulation of amyloid beta peptide deposits in the blood vessel walls results in damage of the blood vessels and hindrance of normal blood flow, making blood vessels more prone to bleeding WEB, Exploring cerebral amyloid angiopathy: Insights into pathogenesis, diagnosis, and treatment,weblink Since CAA can be caused by the same amyloid protein that is associated with Alzheimer's dementia, brain bleedsBOOK, The Behavioral and Cognitive Neurology of Stroke,weblink Cambridge University Press, 2013-02-28, 9781107310896, Olivier, Godefroy, are more common in people who have a diagnosis of Alzheimer's disease. However, they can also occur in those who have no history of dementia. The bleeding within the brain is usually confined to a particular lobeBOOK, Essential Concepts in Molecular Pathology,weblink Academic Press, 2010-02-16, 9780080922188, William B., Coleman, Gregory J., Tsongalis, and this is slightly different compared to brain bleeds which occur as a consequence of high blood pressure (hypertension) – a more common cause of a hemorrhagic stroke (or bleeding in the brain).WEB, Brain Basics: Preventing Stroke: National Institute of Neurological Disorders and Stroke (NINDS),weblink www.ninds.nih.gov, 2015-05-27, The location of the cerebral microbleed determines whether it is more likely to have been caused by hypertension or CAA. Tsai et al. conducted amyloid PET imaging in an Asian population with cerebral amyloid angiopathy–intracerebral hemorrhage and noticed that superficial cerebellar microbleeds are related to CAA, whereas deep or mixed-location cerebellar microbleeds are more likely related to hypertension.JOURNAL, Superficial Cerebellar Microbleeds and Cerebral Amyloid Angiopathy, Stroke, January 2020, 51, 1, 202–208, 10.1161/STROKEAHA.119.026235,weblink 2023-11-17, Tsai, Hsin-Hsi, Pasi, Marco, Tsai, Li-Kai, Chen, Ya-Fang, Chen, Yu-Wei, Tang, Sung-Chun, Gurol, M. Edip, Yen, Ruoh-Fang, Jeng, Jiann-Shing, 31726962,

Causes

(File:Astrocyte5.jpg|thumb|300px|Astrocyte)CAA has been identified as occurring either sporadically (generally in elderly populations)BOOK, Clinical Neurology of the Older Adult,weblink Lippincott Williams & Wilkins, 2008, 9780781769471, Joseph I., Sirven, Barbara L., Malamut, or in familial forms such as Flemish, Iowa, and Dutch types. In all cases, it is defined by the deposition of amyloid beta (Aβ) in the leptomeningeal and cerebral vessel walls.BOOK, Neurologic Differential Diagnosis: A Case-Based Approach,weblink Cambridge University Press, 2014-04-17, 9781107014558, Alan B., Ettinger, Deborah M., Weisbrot, CAA occurring in the Flemish type has been observed to be linked to large dense-core plaques observed in this pedigree.JOURNAL, Dense-core senile plaques in the Flemish variant of Alzheimer's disease are vasocentric, American Journal of Pathology, 2002, 12163376, 161, 2, S., Kumar-Singh, P., Cras, etal, 10.1016/S0002-9440(10)64207-1, 507–20, 1850756, The reason for increased deposition of Aβ in sporadic CAA is still unclear with both increased production of the peptide and abnormal clearance having been proposed as potential causes.BOOK, Neuropathology and Genetics of Dementia,weblink Springer Science & Business Media, 2012-12-06, 9781461512493, Markus, Tolnay, Alphonse, Probst, Under normal physiology Aβ is cleared from the brain by four pathways: (1) endocytosis by astrocytes and microglial cells, (2) enzymatic degradation by neprilysin or insulysin (3) cleared by way of the blood–brain barrier or (4) drained along periarterial spaces. Abnormalities in each of these identified clearance pathways have been linked to CAA.BOOK, Novel Imaging Techniques in Neurodegenerative and Movement Disorders, an Issue of Pet Clinics,weblink Elsevier Health Sciences, 2013-10-15, 9780323227353, Rathan, Subramaniam, Jorge, Barrio, BOOK, Brain Extracellular Matrix in Health and Disease,weblink Elsevier, 2014-10-30, 9780444634948, In familial forms of CAA, the cause of Aβ build up is likely due to increased production rather than poor clearance.BOOK, PACES for the MRCP: with 250 Clinical Cases,weblink Elsevier Health Sciences, 2013-09-17, 978-0702054662, Tim, Hall, Mutations in the amyloid precursor protein (APP), Presenilin (PS) 1 and PS2 genes can result in increased rates of cleavage of the APP into Aβ. An immune mechanism has also been proposed.BOOK, Mental Disorders: New Insights for the Healthcare Professional: 2011 Edition,weblink ScholarlyEditions, 2012-01-09, 9781464900853, BOOK, Advances in Dementia Research and Treatment: 2012 Edition,weblink ScholarlyEditions, 2012-12-26, 9781464991721, apolipoprotein E (APOE) ε2 and ε4 are associated with increased risk of getting cerebral amyloid antipathy. The use of antiplatelet and anticoagulant therapy increases the risk of getting intracerebral haemorrhage in CAA.

Types

Several familial variants exist.JOURNAL, Revesz, Tamas, Holton, Janice L., Lashley, Tammaryn, Plant, Gordon, Rostagno, Agueda, Ghiso, Jorge, Frangione, Blas, Sporadic and familial cerebral amyloid angiopathies, Brain Pathology (Zurich, Switzerland), July 2002, 12, 3, 343–357, 10.1111/j.1750-3639.2002.tb00449.x, 12146803, 8930792, 1015-6305, 8095796, The condition is usually associated with amyloid beta.BOOK, Neurodegeneration: The Molecular Pathology of Dementia and Movement Disorders,weblink John Wiley & Sons, 2011-09-09, 9781444341232, Dennis, Dickson, Roy O., Weller, However, there are types involving other amyloid peptides:

• the "Icelandic type" is associated with cystatin C amyloid (ACys).BOOK, Neuropsychological Neurology: The Neurocognitive Impairments of Neurological Disorders,weblink Cambridge University Press, 2008-04-24, 9780521717922, A. J., Larner,
• the "British type" and "Danish type" are associated with British amyloid (ABri) and Danish amyloid (ADan) respectively. Both peptides are linked to mutations in ITM2B.BOOK, Oxford Textbook of Old Age Psychiatry,weblink OUP Oxford, 2013-09-26, 9780199644957, Tom, Dening, Alan, Thomas,
• Familial amyloidosis-Finnish type is associated with gelsolin amyloid (AGel).JOURNAL, Biffi, Alessandro, Greenburg, Steven M., Cerebral Amyloid Angiopathy: A Systematic Review, Journal of Clinical Neurology, 2011, 7, 1, 1–9, 10.3988/jcn.2011.7.1.1, 21519520, 3079153,

Pathophysiology

The vascular amyloid pathology characteristic of CAA can be classified as either Type 1 or Type 2, the latter type being the more common. Type 1 CAA pathology entails detectable amyloid deposits within cortical capillaries as well as within the leptomeningeal and cortical arteries and arterioles. In type 2 CAA pathology, amyloid deposits are present in leptomeningeal and cortical arteries and arterioles, but not in capillaries. Deposits in veins or venules are possible in either type but are far less prevalent.JOURNAL, Thal, Dietmar Rudolph, Ghebremidhin, Estifanos, Rüb, Udo, Haruyasu, Yamaguchi, Del Tredici, Kelly, Braak, Heiko, Two types of sporadic cerebral amyloid angiopathy, Journal of Neuropathology & Experimental Neurology, 2002, 61, 3, 282–293, 10.1093/jnen/61.3.282, 11895043, free,

Diagnosis

(File:Compare SWI and GRE CAA.png|thumb|450px|MRI showing low signal foci in cerebral amyloid angiopathy. Conventional gradient echo T2*-weighted image (left, TE=20ms), susceptibility weighted image (SWI) and SWI phase image (center and right, respectively, TE=40ms) at 1.5 Tesla.JOURNAL, Susceptibility-Weighted Imaging: Technical Aspects and Clinical Applications, Part 2, American Journal of Neuroradiology, 2009, 0195-6108, 19131406, 232–252, 30, 2, 10.3174/ajnr.A1461, S., Mittal, Z., Wu, J., Neelavalli, E. M., Haacke, 3805373, )CAA can only be definitively diagnosed by a post-mortem autopsy.JOURNAL, Greenberg, Steven, Charidimou, Andreas, Diagnosis of Cerebral Amyloid Angiopathy: Evolution of the Boston Criteria, Stroke, 2018, 49, 2, 491–497, 10.1161/STROKEAHA.117.016990, 29335334, 5892842, Biopsies can play a role in diagnosing probable cases.BOOK, Cerebral Amyloid Angiopathy in Alzheimer's Disease and Related Disorders,weblink Springer Science & Business Media, 2013, 9789401710077, M. M., Verbeek, R. M. de, Waal, Harry V., Vinters, When no tissue is available for biopsy, the Boston Criteria are used to determine probable CAA cases from MRI or CT scan data. The Boston Criteria require evidence of multiple lobar or cortical hemorrhages to label a patient as probably having CAA. Susceptibility weighted imaging has been proposed as a tool for identifying CAA-related microhemorrhages.BOOK, Principles of Neurological Surgery,weblink Elsevier Health Sciences, 2012, 978-1437707014, Richard G., Ellenbogen, Saleem I., Abdulrauf, Laligam N., Sekhar,

Imaging

Cerebral amyloid angiopathy can be presented with lobar intracerebral hemorrhage or microbleeds in the brain. The bleeding usually occurs on the surfaces of the brain in contrast with intracranial haemorrhage due to high blood pressure which occurs in deep locations of the brain such as basal ganglia and pons. In lobar intracerebral bleed, computed tomography (CT) scan would show hyperdense haemorrhage area and hypodense odema around the haemorrhagic site.JOURNAL, Sharma, Rohit, Dearaugo, Stephanie, Infeld, Bernard, O'Sullivan, Richard, Gerraty, Richard P, August 2018, Cerebral amyloid angiopathy: Review of clinico-radiological features and mimics, Journal of Medical Imaging and Radiation Oncology, en, 62, 4, 451–463, 10.1111/1754-9485.12726, 29604173, free, MRI sequence of gradient echo and susceptibility weighted imaging (SWI) are useful in detecting microbleeds and deposition of iron on the brain cortex (cortical superficial siderosis). Other MRI indicators of CAA include white matter hyperintensities and cortical thinning.JOURNAL, Charidimou, Andreas, Boulouis, Gregoire, Gurol, M. Edip, Ayata, Cenk, Bacskai, Brian J., Frosch, Matthew P., Viswanathan, Anand, Greenberg, Steven M., Emerging concepts in sporadic cerebral amyloid angiopathy, Brain, 1 July 2017, 140, 7, 1829–1850, 10.1093/brain/awx047, 28334869, 6059159, en, 0006-8950,

Management

The aim in cerebral amyloid angiopathy is to treat the symptoms, as there is no current cure. Physical, occupational and/or speech therapy may be helpful in the management of this condition.

History

Gustav Oppenheim was the first to report vascular amyloid β deposits on the vasculature of the central nervous system in 1909. The first paper focusing solely on what would come to be known as CAA was published in 1938 by WZ Scholz. In 1979, H. Okazaki published a paper implicating CAA in certain cases of lobar intracerebral hemorrhage. The Boston Criteria for CAA originated in a 1995 paper from Harvard Medical School.

References

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Further reading

• JOURNAL, Cerebral Amyloid Angiopathy: CT and MR Imaging Findings, RadioGraphics, September 1, 2006, 0271-5333, 1517–1531, 26, 5, 10.1148/rg.265055090, Christine P., Chao, Amy L., Kotsenas, Daniel F., Broderick, 16973779, free,

External links

{{Medical resources| DiseasesDB = 32874I068}}| ICD9 =| ICDO =| OMIM =| MedlinePlus = 000719| eMedicineSubj = neuro| eMedicineTopic = 628| MeshID = D016657}}{{Scholia|topic}}{{Amyloidosis}}{{Medicine}}{{Authority control}}