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

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
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]

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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]

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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