Cerebral Amyloid Angiopathy: Causes, Symptoms, Diagnosis and Treatment

It is a disease caused by an accumulation in the walls of the blood vessels of an abnormal protein called amyloid.

The deposition of β-amyloid is carried out in the small and medium arteries and, less frequently, in the veins of the cerebral cortex and in the thin covering that covers the brain and the spinal cord under the dura, called the leptomeninge.

This causes these blood vessels to become very brittle and tends to break easily, causing bleeding in the brain.

This is considered as a form of stroke, which is dominated intracerebral hemorrhage, which is caused by the lack of blood flow and is called ischemic stroke.

Cerebral amyloid angiopathy (CAA) has one of the morphological characteristics of Alzheimer’s disease; amyloid is the same abnormal protein that is deposited in the brain in Alzheimer’s disease.

However, they have also been found in neurologically healthy brains of elderly patients.

Cerebral amyloid angiopathy does not affect blood vessels in other parts of the body, it only affects the blood vessels located in the brain.

Causes

The cause of cerebral amyloid angiopathy is unknown, the reason for the increased deposition of Aβ, still not very clear, is believed to be a probable genetic defect present in the amyloid protein gene.

symptom

Cerebral amyloid angiopathy is often asymptomatic, which can cause dementia, intracranial hemorrhage, or transient neurological events.

These symptoms may also include seizures and cognitive decline.

Cerebral amyloid angiopathy is an increasingly important cause of hemorrhagic strokes in older adults, it also contributes to the growing vascular cognitive deterioration. This occurs in patients with cerebral amyloid angiopathy without having suffered a hemorrhagic stroke.

Diagnosis

Usually the tests used to rule out bleeding caused by cerebral amyloid angiopathy from other causes of cerebral hemorrhage include angiography, CT scans, MRIs, and blood tests.

High levels of blood pressure can cause brain hemorrhages, but these are usually located in a different place in the brain than lobar hemorrhages caused by cerebral amyloid angiopathy.

The images observed through the magnetic resonances can help with the diagnosis, showing small asymptomatic cerebral hemorrhages caused by the cracking of the blood vessels.

Within the guidelines for diagnosis, four levels of certainty are considered for the diagnosis of cerebral amyloid angiopathy. The levels are characterized as follows:

  • Definitive cerebral amyloid angiopathy

Complete postmortem examination revealed cortical, lobar, or subcortical cortical hemorrhage that is evidence of severe cerebral amyloid angiopathy.

  • Probable cerebral amyloid angiopathy with pathological test

It is called in this way because there is pathological evidence of support. The existence of clinical data and pathological tissue (evacuated hematoma or cortical biopsy sample) show that there was hemorrhage with the aforementioned characteristics and a certain degree of vascular amyloid deposition is evident.

  • Probable cerebral amyloid angiopathy

In the clinical data and in the findings of magnetic resonance imaging (MRI) images (in the absence of a pathological sample) they show the existence of multiple hematomas in a patient over 60 years of age.

  • Possible cerebral amyloid angiopathy

This diagnosis is considered if the patient is over 60 years of age and the clinical and MRI findings reveal the occurrence of a single subcortical lobar, cortical or cortical hemorrhage without any other cause; as well as multiple hemorrhages with a possible cause, but not definitive; or the existence of some hemorrhage in an atypical place.

The first three levels require that no other cause of bleeding has been recorded.

Treatment

Cerebral amyloid angiopathy (CAA) has no treatment at this time. The treatment of intracranial hemorrhage related to cerebral amyloid angiopathy is identical to the standard management of hemorrhagic stroke.

In this treatment, special attention is given to the reversal of hemorrhage, to the management of intracranial pressure and the prevention of subsequent complications.

If a diagnosis of vasculitis is found on angiography and brain biopsy, a long-term treatment, up to 1 year, with steroids and cyclophosphamide will be indicated.