CEREBRAL HEMORRHAGE
Cerebral amyloid angiopathy (CAA)
Created 13/04/2021, last revision 07/05/2023
- a heterogeneous group of sporadic or familial disorders characterized by deposition of amyloid beta-peptide (Aβ) in the walls of small to medium-sized cerebral and leptomeningeal vessels in the absence of systemic amyloidosis
- sporadic form affects mainly the elderly population
- rare familial forms (Icelandic, Arctic, or Dutch type) occur at younger ages
- CAA is responsible for ~2-10% of primary intracranial hemorrhages (30-70% of lobar hematomas in elderly patients) [Chao, 2006]
- CAA may also present with transient neurological symptoms or encephalopathy
Pathology
- amyloid deposition in small to medium-sized cerebral arteries without systemic amyloidosis
- type 1 CAA- amyloid deposits within cortical capillaries, leptomeningeal and cortical arteries, and arterioles
- type 2 CAA – deposits are present in leptomeningeal and cortical arteries but not in capillaries
- there is some association with typical Alzheimer’s changes, such as neuritic plaques and neurofibrillary tangles
- the reason for the increased deposition of Aβ in sporadic CAA is still unclear (a combination of increased production of the peptide with abnormal clearance has been proposed)
- increased production is the dominant cause in familial forms
- apolipoprotein E (APOE) ε2 and ε4 are associated with an increased risk of CAA

Clinical presentation
- Transient Focal Neurological Episodes (TFNE), also called “amyloid spells“
- recurrent lobar intracerebral hemorrhage (ICH)
- convexial SAH
- hemocephalus
- arteriolopathy with leukoaraiosis and encephalopathy
- development of vascular dementia in advanced stages of the disease
- transient positive and negative symptoms (also called “amyloid spells”)
- positive symptoms – “aura-like” spreading paresis, visual phenomena (monocular blurred vision, flashes, teichopsia), limb twitching
- negative symptoms – transient focal symptoms – paresis, speech, and visual disturbances
- positive symptoms predominate
- usually, there are multiple stereotyped episodes, typically lasting 10-30 minutes
- occurs in approx. 14% of CAA patients [Charidimou, 2012]
- very often caused by convexial SAH
- FLAIR, DWI/ADC, and GRE/SWI are optimal for diagnostic workup
- frequently, convexial SAH is seen along with microbleeds or parenchymal hematoma, but also with recent lesions on DWI – etiology is heterogeneous
- FLAIR, DWI/ADC, and GRE/SWI are optimal for diagnostic workup
- may be confused with TIA (antithrombotic drugs further increase the risk of ICH) or stroke (high risk of ICH during thrombolysis)
- TFNE is often followed by subsequent ICH (37.5%/2 months)!! [Charidimou, 2012]
Diagnostic evaluation
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Therapy
- no causal treatment
- monitor and treat arterial hypertension
- treat acute hematoma according to standard protocols → management of intracerebral hemorrhage
- antiplatelet and anticoagulant therapy increases the risk of bleeding ⇒ assess individual risk-benefit ratio in each patient (Biffi, 2010]
Anticoagulation in patients with suspected CAA
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Thrombolysis in patients with suspected CAA
- IVT is feasible in a patient with CMBs < 10 (AHA/ASA 2019 IIa/B-NR)
- with CMBs >10, IVT is associated with a higher risk of ICH; the expected benefit of treatment must outweigh the risk (AHA/ASA 2019 IIb/B-NR)
- consider IVT in a patient with a severe deficit without poor premorbid condition