Cerebral angiopathy is a general term for disorders caused by abnormalities within the walls of blood vessels in the brain. These conditions compromise the integrity of cerebral vessels, which can disrupt normal blood flow. This weakening of the vessel walls can also lead to bleeding into the surrounding brain tissue.
Causes and Major Types of Cerebral Angiopathy
The causes of cerebral angiopathy are diverse, involving the gradual accumulation of abnormal substances within arterial walls, inflammatory processes, or genetic predispositions. This buildup stiffens and weakens the vessels, making them prone to cracking and rupture. The specific protein or genetic mutation involved defines the type of angiopathy and its progression.
A common form of this condition is Cerebral Amyloid Angiopathy (CAA), where a protein called amyloid-beta accumulates in the walls of small and medium-sized arteries. This is the same protein associated with the plaques in Alzheimer’s disease, and CAA is frequently identified in older individuals. The amyloid deposits cause vessel walls to become brittle, resulting in tiny microbleeds or larger hemorrhages. CAA occurs sporadically and is strongly linked to the aging process.
Another type is CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy). Unlike CAA, CADASIL is a hereditary condition caused by mutations in the NOTCH3 gene. This defect leads to the accumulation of granular osmiophilic material in the brain’s small arteries. This buildup damages the vessel walls, obstructing blood flow and leading to recurrent small strokes (subcortical infarcts) and widespread changes to the brain’s white matter.
Other rare hereditary forms of cerebral angiopathy exist, each linked to different genetic mutations and proteins. For example, the “Icelandic type” is associated with the protein cystatin C. The “British” and “Danish” types involve mutations related to a protein known as ITM2B.
Recognizable Signs and Symptoms
The signs of cerebral angiopathy can be subtle and develop gradually, depending on the disorder’s type and the location of affected blood vessels. Many individuals may have no noticeable symptoms, with the condition discovered incidentally during brain imaging. When symptoms appear, they result from bleeding or reduced blood flow that damages brain tissue.
Cognitive changes are a common manifestation, ranging from mild memory difficulties to a more progressive cognitive decline. This can affect executive functions, including reasoning, planning, and problem-solving. Headaches are another symptom, which can be temporary or recurrent.
Focal neurological events, which are sudden episodes of dysfunction in a specific brain area, can also occur. These can include sudden weakness on one side of the body, speech difficulty, or sensation changes, mimicking a transient ischemic attack (TIA). Seizures are also a possible symptom, resulting from the irritation of brain tissue by blood. The severity of these signs varies from undetectable microbleeds to major brain hemorrhages.
The Diagnostic Process
Diagnosing cerebral angiopathy begins with a thorough evaluation of a person’s medical history and a neurological exam, including questions about the onset and nature of symptoms like headaches or cognitive changes. This assessment helps rule out other potential causes.
The main tool for identifying changes is brain imaging, with Magnetic Resonance Imaging (MRI) being the preferred method. On an MRI, radiologists look for signs like cerebral microbleeds, which appear as small, dark spots in cases of CAA. Another finding is leukoencephalopathy, or changes to the brain’s white matter, a prominent feature of CADASIL.
Computed tomography (CT) scans are also used, especially in emergencies, to detect larger areas of bleeding. For hereditary forms like CADASIL, a diagnosis can be confirmed through genetic testing for mutations in the NOTCH3 gene. A brain biopsy can provide conclusive evidence by showing protein deposits in vessel walls, but it is rarely performed due to its invasive nature.
Management and Treatment Approaches
There is currently no cure for most forms of cerebral angiopathy, so medical care focuses on managing symptoms and reducing complication risks. A primary strategy is controlling vascular risk factors. This involves managing high blood pressure, as hypertension can strain weakened blood vessels and increase the likelihood of hemorrhage.
Individuals experiencing recurrent headaches or seizures may be prescribed medications to control these episodes. Cognitive symptoms may be addressed through supportive care. In some cases, medications used for dementia might be considered.
Stroke prevention is another aspect of management. The use of antiplatelet or anticoagulant medications (blood thinners) must be carefully weighed, especially in CAA, as they can increase the risk of bleeding. Supportive therapies, including physical, occupational, and speech therapy, can also help individuals recover from the effects of a stroke or manage progressive symptoms.