The central nervous system is the most important part of the human body due to its ability to control all the functions of the body. It has mainly consisted of two parts including; brain and spinal cord. The brain is known as the center of control where all the thoughts and body movements are organized along with the interpretation of the external environment.
Under specific circumstances, a protein named beta-amyloid accumulates in the walls of small to medium blood vessels (mostly in the arteries and less frequent in the veins) of the central nervous system as well as meninges. This condition is known as cerebral amyloid angiopathy (CAA). This deposition of amyloid is only seen in the brain so the disorder is not related to any other form of amyloidosis called systemic amyloidosis.
This condition is found secondary in many patients who already suffering from Alzheimer’s disease (AD) but it is also found in the brains of the elderly population having healthy neurological systems. Meanwhile, in many cases, cerebral amyloid angiopathy may lead to dementia, intracranial hemorrhage or any other transient neurologic events.
Cerebral Amyloid Angiopathy Symptoms:
Beta-amyloid is the protein that causes this condition and also responsible for the occurrence of Alzheimer’s disease (AD). So the patients experiencing Alzheimer’s dementia and brain bleeds are considered prone to cerebral amyloid angiopathy (CAA) but it is also found in the cases who have shown no history of dementia. As the brain bleeds are also experienced in many other medical conditions such as hypertension which is considered to be the most common reason for the hemorrhage strokes commonly known as the brain bleeds. But the brain bleeds resulting from the CAA are distinguished on the location confined to the particular lobe of the brain which makes them slightly different.
There are many signs and symptoms which can be used as an indication for the hereditary cerebral amyloid angiopathy including;
- Recurrent strokes and dementia in the population having Flemish and Italian types of CAA.
- Frequent strokes, impaired movements, numbness, tingling, confusion or dementia in the patients having Piedmont type of CAA.
Other than hereditary cerebral amyloid angiopathy may include the symptoms;
- Dementia
- Brain bleeds
Cerebral Amyloid Angiopathy Causes
CAA is generally identified in the elderly population or many familial forms such as Iowa, Flemish, and Dutch.
The major cause of this condition is known to be the deposition of beta-amyloid in the walls of cerebral meninges and vessels. In the Flemish type of CAA, several large plaques are observed in the pedigree as dense-core deposits.
This accumulation is caused due to the two reasons including;
- Over-production of the beta-amyloid protein
- Abnormal clearance of the beta-amyloid protein
- Mutations in amyloid precursor proteins
The underlying reason for these abnormalities is still unknown. As under normal conditions, the beta-amyloid is flushed out from the body through four different pathways known as;
- Endocytosis through microglial cells and astrocytes
- Enzymatic degradation
- Through blood-brain barrier
- Cleared by drainage through periarterial spaces.
So any kind of interruption or modification may cause the abnormality in these pathways and lead to the poor clearance resulting in the deposition of beta-amyloid especially in the case of the elderly population. Meanwhile, in the case of familial types of CAA, the over-production of beta-amyloid is considered to be the reason.
Different types of hereditary CAA are caused due to the genetic mutations involving Dutch, Italian, Iowa, Flemish, and piedmont type.
Cerebral Amyloid Angiopathy Diagnosis
A few tools have been suggested by the professionals to investigate CAA, including;
- Susceptibility weighted imaging
- Biopsies
CAA enhances the risk of intracerebral hemorrhage (ICH) so the choice of diagnostic tool is very important to detect the signs of this condition including; micro-bleeds, prior lobar ICH, or cortical superficial siderosis.
Cerebral Amyloid Angiopathy Treatment
There is no cure for this condition so professionals mainly focus on the treatment of the symptoms. This disease can be managed by several ways commonly known as;
- Physical therapy
- Occupational therapy
- Speech therapy
The type of management also depends upon the severity of the condition as in case of aggressive experience of associated hypertension, acute management is recommended. This acute management involves the control of hypertension and the provision of supportive care and alternatively, it is known as supportive management.
Patients suffering from this condition named CAA should be avoided for the implementation of antiplatelet and anticoagulant therapies as these only made the condition worse. This is called chronic management which mainly aims for the minimization of the re-bleeding by avoiding the above-stated therapies in the specified patients.
Surgical removals are not recommended as these have not been proven very beneficial in history.