Cerebral amyloid angiopathy
Cerebral amyloid angiopathy is deposition of amyloid beta in the walls of small and medium-sized cortical and leptomeningeal arteries, making superficial vessels fragile; it is the most common cause of lobar intracerebral hemorrhage in older adults and also causes cortical microbleeds, superficial siderosis, and vascular dementia. Acute hemorrhage is managed like any intracerebral hemorrhage, and long-term care centers on blood pressure control and avoiding anticoagulation because recurrence risk is high.
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What this article covers
- Overview
Definition: cerebral amyloid angiopathy (CAA) is deposition of amyloid beta protein, similar to the neuritic plaques of Alzheimer disease, in the walls of small and medium-sized cerebral arteries…
- Epidemiology
Most common cause of lobar ICH: CAA is the leading cause of lobar hemorrhage and, after hypertension, the second most common cause of ICH in older adults.
- Risk factors
Advanced age: the dominant risk factor, rising sharply after 55 and highest after 75.
- Pathophysiology
Amyloid deposition: amyloid beta deposits in the walls of cortical and leptomeningeal arterioles, the same protein that forms the extracellular neuritic plaques of Alzheimer disease.
- Clinical features
Acute lobar ICH: sudden focal deficit with headache and impaired consciousness, which separate hemorrhage from ischemic stroke; the deficit tracks the lobe involved.
- Differential diagnosis
Hypertensive ICH: deep location (putamen, thalamus, pons, cerebellum) in a patient with long-standing hypertension, rather than a lobar, cortical bleed.
- Diagnosis
Diagnosis is established on imaging in an older patient: one or more lobar hemorrhages, cortical microbleeds, or cortical superficial siderosis in a patient older than 55, with deep structures spared…
- Management
First, stabilize the airway and lower blood pressure: protect the airway for a GCS of 8 or less, and for a presenting systolic pressure of 150 to 220 mm Hg treat to a target systolic of 140 mm Hg…
- Complications
Recurrent lobar ICH: the defining long-term risk, higher than after hypertensive deep ICH.
- Prognosis
ICH score predicts 30-day mortality: death rises with age 80 or older, volume over 30 mL, GCS below 13, intraventricular extension, and infratentorial location.
- Prevention
Blood pressure below 130/80 mm Hg after any ICH, continued indefinitely, is the main modifiable measure against recurrence.
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- Alzheimer disease
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- Vascular dementia
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- Ischemic stroke
Ischemic stroke is sudden focal neurologic deficit from arterial occlusion confirmed by infarction on neuroimaging. Diagnosis relies on urgent noncontrast head CT to exclude hemorrhage; treatment is IV alteplase within 4.5 hours and mechanical thrombectomy for large-vessel occlusion within an extended window, followed by antiplatelet therapy and risk-factor control.
- Subarachnoid hemorrhage
Subarachnoid hemorrhage is sudden bleeding into the subarachnoid space, most often from a ruptured saccular (berry) aneurysm, presenting as the worst headache of a patient's life. Diagnosis is noncontrast head CT, then lumbar puncture if CT is negative, then catheter angiography to define the aneurysm; management is early aneurysm securement, blood pressure control, and nimodipine to reduce delayed cerebral ischemia from vasospasm.
- Anticoagulants
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