Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) happens when amyloid (abnormal) proteins build up in blood vessels in your brain. The proteins damage your blood vessels and cause bleeding inside your brain. The condition is the most common cause of cognitive decline in people aged 60 and older. Treatment manages issues that may increase bleeding in your brain.


What is cerebral amyloid angiopathy?

Cerebral amyloid angiopathy (CAA) is a condition that causes bleeding inside your brain that damages your brain tissue. It happens when amyloid (abnormal) proteins build up in your brain’s blood vessels and make your blood vessels leaky. This leads to bleeding in your brain that can be small (microbleeds) or larger brain bleeds (intracranial hemorrhage).

Cerebral amyloid angiopathy is the most common cause of cognitive decline, which is when you gradually lose your thinking abilities. Experts estimate that 23% to 29% of people in the general population above the age of 50 have moderate to severe cerebral amyloid angiopathy.


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Symptoms and Causes

What are cerebral amyloid angiopathy symptoms?

Symptoms vary depending on how much blood is leaking into your brain. For example, you could have cerebral amyloid angiopathy without having symptoms. That can happen if you only have silent microbleeds, when very little blood is seeping into your brain. But if you have a large brain bleed, you may have neurological issues like confusion or difficulty talking. In some cases, a large brain bleed may lead to coma. In some cases, people learn they have cerebral amyloid angiopathy after having a brain MRI for another issue.

More severe bleeding causes noticeable symptoms like:

What happens when you have cerebral amyloid angiopathy?

Cerebral amyloid angiopathy is a type of hemorrhagic stroke. If you have this condition, there are clumps of amyloid (abnormal) proteins that cling to the inside wall of blood vessels in your brain.

Over many years, your blood vessel walls gradually weaken and develop microscopic cracks or fissures that let blood seep into your brain. When blood leaks from ruptured vessels, it damages brain tissue.

Often, this blood flow is like a very slow leak of air from a tire. If you’re like most people, you won’t notice changes like memory loss or confusion. And when you do, you may think those symptoms are a natural consequence of growing older. But symptoms get worse over time as amyloid proteins do more damage to your blood vessel walls and larger amounts of blood flow into your brain.

Can cerebral amyloid angiopathy develop quickly?

It can, but that usually happens if you inherit certain genetic mutations (changes) that cause the condition. For example, the most common type of inherited cerebral amyloid angiopathy causes life-threatening strokes.

These serious strokes are the first symptom. People who survive a stroke often have dementia, epilepsy and recurring strokes that do further damage to their brains. Most people with this type of cerebral amyloid angiopathy die within 10 years of developing symptoms. Inherited cerebral angiopathy is very rare.

What causes cerebral amyloid angiopathy?

Experts don’t know the exact cause, but research suggests the following conditions or situations may increase your risk:


Diagnosis and Tests

How is cerebral amyloid angiopathy diagnosed?

There’s no conclusive way to diagnose this condition while a person is alive. The only way to do that is to examine samples of a person’s brain under a microscope, which is only possible during an autopsy after death.

While experts may not be able to confirm cerebral amyloid angiopathy before death, they can still make a highly probable presumptive diagnosis based on a brain MRI or positron emission tomography (PET) scan with amyloid tracer labeling.

Management and Treatment

Is there a cure for cerebral amyloid angiopathy?

No, there isn’t a cure or a way to prevent this condition. If imaging tests show you may have this condition, your healthcare provider will focus on ways to reduce the chance you’ll develop brain bleeds, have more brain bleeds or have more severe brain bleeds.

For example, chronic hypertension increases your risk of brain bleeds. If tests show signs of cerebral amyloid angiography and you have hypertension, your provider will carefully watch your overall health and blood pressure. They may recommend medication and lifestyle changes to reduce blood pressure.

If you have cerebral amyloid angiopathy and you take anticoagulants (blood-thinning medication) for conditions like a blood clotting disorder, it could increase the chance that bleeding in your brain will get worse. If that’s your situation, your provider will recommend that you stop your anticoagulant medication and suggest other ways to keep your blood from clotting.


Outlook / Prognosis

How long can you live with cerebral amyloid angiopathy?

That depends on your situation. Factors like your age, symptoms and overall health, including conditions that increase your risk of developing serious brain bleeds, will have an impact on how long you’ll live. Your healthcare provider is your best resource for information about what you can expect.

Living With

How do I take care of myself?

Understanding your risk is the best way to take care of yourself. For example, if tests show you have cerebral amyloid angiopathy, but you don’t have symptoms, your healthcare provider will recommend ways you can avoid high blood pressure or the need to take blood thinners.

When should I see my healthcare provider?

Contact your provider right away if your symptoms get worse. For example, cerebral amyloid angiopathy affects your thinking abilities, like your memory. If you or those close to you notice you’re having memory issues, your provider may want to order imaging tests to check for new bleeding in your brain.

When should I go to the emergency room?

You should go to the emergency if symptoms like headache, confusion or difficulty speaking suddenly become worse. You may be having a hemorrhagic stroke that can cause permanent brain damage or death. Stroke warning signs include:

  • Muscle weakness or paralysis that affects your face so one or both sides of your face droop when you smile.
  • Muscle weakness in your arms, with one arm being weaker than the other.
  • More difficulty speaking.
  • Sudden severe headache.

What questions should I ask my doctor?

Here are some suggested questions if tests show you may have cerebral amyloid angiopathy:

  • What do imaging tests show?
  • Will the bleeding in my brain get worse?

Additional Common Questions

Is cerebral amyloid angiopathy the same as dementia?

No, it’s not, but there is a connection: Cerebral amyloid angiopathy causes hemorrhagic stroke, which can lead to vascular dementia.

A note from Cleveland Clinic

Cerebral amyloid angiopathy (CAA) is bleeding in your brain. It causes symptoms like cognitive decline, which is the gradual loss of thinking abilities like memory and reasoning. Cognitive decline often starts when you’re age 50 and older, so you could think age alone is why you have trouble remembering a word. But changes that seem to be getting worse could be symptoms of cerebral amyloid angiopathy — and reasons to talk to a healthcare provider.

Medically Reviewed

Last reviewed on 03/07/2024.

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