Cerebral amyloid angiopathy

Definition

Cerebral amyloid angiopathy is a neurological condition in which proteins called amyloid build up on the walls of the arteries in the brain. The condition increases the risk of hemorrhagic stroke and dementia.

Alternative Names

Amyloidosis - cerebral; CAA

Causes, incidence, and risk factors

The cause of cerebral amyloid angiopathy is unknown. Persons with this condition have deposits of amyloid protein in the walls of the brain arteries. The protein is usually not deposited anywhere else in the body.

The major risk factor is increasing age. The rate of the condition is much greater in those older than 60.

Symptoms

Cerebral amyloid angiopathy can cause bleeding into the brain, usually in the outer parts of the brain, called the lobes, and not the deep areas. Symptoms occur because bleeding in the brain harms brain tissue. If there is a lot of bleeding, immediate symptoms occur and resemble a stroke. Such symptoms include:

• Drowsiness
• Headache (usually in a specific part of the head)
• Neurologic changes that may start suddenly, including:
  • Confusion, delirium
  • Double vision, decreased vision
  • Sensation changes
  • Speech difficulties
  • Weakness or paralysis
• Seizures
• Stupor or coma (rarely)
• Vomiting

Other symptoms can include:

• Episodes of confusion
• Headaches that come and go
• Loss of mental function (dementia)
• Sensation changes (unusual sensations) that come and go
• Seizures

Signs and tests

Cerebral amyloid angiopathy is difficult to diagnose with certainty without a sample of brain tissue. This is usually done after death or when a biopsy of the blood vessels of the brain is done.

A physical exam can be relatively normal if you have a small bleed, but you may show some brain function changes. It is important for the doctor to ask detailed questions about your medical history. Your symptoms and the results of your physical exam and any imaging tests may cause your doctor to suspect this problem.

A CT scan or MRI of the head may show:

• Bleeding in the brain
• Signs of prior bleeding in the brain

Magnetic resonance angiography (MRA) of the brain can help with the diagnosis of large bleeds and may be used to rule out arteriovenous malformation or aneurysm as the cause of the bleed.

Another type of MRI scan can help show tiny areas where blood has escaped from blood vessels into brain tissue.

Treatment

There is no known effective treatment. The goal of treatment is to relieve symptoms. In some cases, rehabilitation is needed for weakness or clumsiness. This can include physical, occupational, or speech therapy.

Occasionally, some patients may benefit from medications that help improve memory, such as those used to treat Alzheimer's disease.

Seizures, sometimes called “amyloid spells,” may be treated with anticonvulsants such as phenytoin (Dilantin) and carbamazepine (Tegretol).

Support Groups

Expectations (prognosis)

The disorder slowly gets worse but varies from person to person.

Complications

• Dementia
• Hydrocephalus (rarely)
• Seizures
• Repeated episodes of bleeding in the brain

Calling your health care provider

Go to the emergency room or call the local emergency number (such as 911) if you have a sudden loss of movement, sensation, vision, or speech.

Prevention

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References

Kinnecom C, Lev MH, Wendell L, et al. Course of cerebral amyloid angiopathy-related inflammation. Neurology. 2007 Apr 24;68(17):1411-6.

Zivin JA. Hemorrhagic cerebrovascular disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 432.