Cerebral amyloid angiopathy (CAA)

Created 13/04/2021, last revision 09/05/2022

  • a heterogeneous group of sporadic or familial diseases characterized by amyloid deposits in the walls of small and medium-sized cerebral vessels
  • mainly affects older people, rare familial forms (Icelandic and Dutch type) appear in younger age
  • CAA is responsible for ~2-10% of primary intracranial hemorrhages (30-70% of lobar hematomas in elderly patients) [Chao, 2006]


  • amyloid deposits in small and medium-sized cerebral arteries without systemic amyloidosis
  • some association exists with typical Alzheimer’s changes such as neuritic plaques and neurofibrils
Cerebral amyloid angiopathy

Clinical presentation

  • Transient Focal Neurological Episodes (TFNE), also called “amyloid spells
  • recurrent lobar intracerebral hemorrhages (ICH)
  • convexial SAH
  • hemocephalus
  • arteriolopathy with leukoaraiosis and encephalopathy
  • development of vascular dementia at an advanced stage of the disease
  • transient positive and negative symptoms (also “amyloid spells”)
    • positive symptoms – “aura-like” spreading paresis, visual phenomena (monocular blurred vision, flashes, teichopsia), twitching of limbs
    • negative symptoms – transient focal symptoms – paresis, speech disorders, visual
  • positive symptoms predominate
  • usually, there are multiple stereotyped episodes, typically lasting 10-30 minutes
  • occurrence in about 14% of CAA patients [Charidimou, 2012]
  • very often caused by the convexial SAH
    • FLAIR, DWI/ADC, and GRE/SWI are optimal for diagnostic workup
    • frequently, there is a detection of convexial SAH as well as microbleeds or parenchymal hematoma, but also fresh lesions on DWI – thus, the etiology is heterogeneous
  • there is possible confusion with TIA (antithrombotic drugs further increase the risk of ICH) or stroke (high risk of ICH during thrombolysis)
  • the occurrence of TFNE is often followed by subsequent ICH (37.5% / 2 months)!! [Charidimou, 2012]

Diagnostic evaluation

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  • currently, there is no causal treatment
  • treat hematoma according to standard protocols   → treatment of intracerebral hemorrhage
  • antiplatelet and anticoagulant therapy increases the risk of bleeding ⇒ individual risk-benefit assessment in each patient  (Biffi, 2010]

Anticoagulation in patients with suspected CAA

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Thrombolysis in patients with suspected CAA

  • in a patient with CMBs < 10, IVT is possible (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 severe deficit in a patient without premorbid severe condition
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