Angiopathy is the generic term for a disease of the blood vessels (arteries, veins, and capillaries). [1] This also refers to the condition of damage or rupture of small blood vessels. The best known and most prevalent angiopathy is diabetic angiopathy , a common complication of chronic diabetes.
There are two types of angiopathy: macroangiopathy and microangiopathy . [2]
In macroangiopathy, atherosclerosis and a resultant blood clot forms on the large blood vessels, sticks to the vessel walls, and blocks the flow of blood. Macroangiopathy in the heart is coronary artery disease; in the brain, it is cerebrovascular disease. Macroangiopathy may cause other complications, such as ischemic heart disease, stroke and peripheral vascular disease which contributes to the diabetic foot ulcers and the risk of amputation.
In microangiopathy, the walls of the smaller blood vessels become so thick and weak that they bleed, leak protein, and slow the flow of blood through the body. The decrease of blood flow through stenosis or clot formation impairs the flow of oxygen to cells and biological tissues (called ischemia) and leads to cellular death (necrosis and gangrene, which in turn may require amputation). Thus, tissues which are very sensitive to oxygen levels, such as the retina, develop microangiopathy and may cause blindness (so-called proliferative diabetic retinopathy). Damage to nerve cells may cause peripheral neuropathy, and to kidney cells, diabetic kidney disease (Kimmelstiel-Wilson syndrome).
It is also possible to classify angiopathy by the associated condition: [3]
Chronic diabetes can lead to several problems, one of which is Diabetic Angiopathy. Individuals with diabetic angiopathy notice a constriction in their arteries. This cause many organs to receive insufficient blood and oxygen, which might eventually cause harm. High blood sugar is the primary cause of diabetic angiopathy. Excessive blood sugar levels have the potential to harm tissues and cells. [4]
A form of cerebrovascular illness known as Cerebral Amyloid Angiopathy (CAA) is typified by the buildup of amyloid beta-peptide in the leptomeninges and small to medium sized cerebral blood vessels. [5] Amyloid buildup causes brittle blood vessels, which can lead to lobar intracerebral hemorrhages (ICH). In addition, hemosiderosis, inflammatory leukoencephalopathy, Alzheimer's disease, accidental microbleeds, cognitive deficits, and transitory neurological symptoms may manifest. [6]
The cause of Cerebral Amyloid Angiopathy are unknown. Sometimes it can be hereditary, however, there have been cases where it is developed in the elderly, especially in people over 55 years of age. [3]
High blood sugar is the primary cause of diabetic angiopathy. The endothelium, a smooth layer of the cell wall, is weakened and the artery-lining cells are injured. Rough patches develop along the endothelium and may promote the accumulation of deposits known as plaque. These deposits gradually harden and become more noticeable over time, restricting (stenosing) the artery and impairing normal blood flow. Different organs receive insufficient oxygen-rich blood due to the bottleneck that was formed. [4]
Individuals with cerebral amyloid angiopathy typically have no symptoms. However, spontaneous lobar bleeding is the most frequent clinical sign when symptomatic. The clinical impairments are primarily determined by the site and extent of the bleeding. Larger hemorrhages may result in greater focused deficits, headaches, seizures, speaking difficulties, and muscular weakness. Smaller hemorrhages may produce hemiplegia and diminished consciousness. [7]
Currently, while there is no cure for angiopathy, there are ways through which the symptoms can be managed. For example, therapies. Treatment options for situations of muscle weakness may include speech, occupational, or physical therapy. Medication can be used for potential seizures and memory loss. [3]
lobar intracerebral hemorrhages(ICH) linked to CAA is often recurring. Due to this high prevalence, when there isn't a clear justification for anticoagulation, doctors usually avoid antiplatelet medicines and anticoagulants. Notably, research has shown that people with atrial fibrillation benefit from restarting anticoagulation. [8]
Despite the fact that CAA does not appear to be primarily caused by hypertension, blood pressure reduction has also been linked to advantages in terms of mortality.[8] Blood pressure control reduced the risk of CAA-related ICH by 77%. [9]
Finally, a small body of research has demonstrated the advantages of using immunosuppression to treat the inflammatory forms of CAA. [10]
Cerebrovascular disease includes a variety of medical conditions that affect the blood vessels of the brain and the cerebral circulation. Arteries supplying oxygen and nutrients to the brain are often damaged or deformed in these disorders. The most common presentation of cerebrovascular disease is an ischemic stroke or mini-stroke and sometimes a hemorrhagic stroke. Hypertension is the most important contributing risk factor for stroke and cerebrovascular diseases as it can change the structure of blood vessels and result in atherosclerosis. Atherosclerosis narrows blood vessels in the brain, resulting in decreased cerebral perfusion. Other risk factors that contribute to stroke include smoking and diabetes. Narrowed cerebral arteries can lead to ischemic stroke, but continually elevated blood pressure can also cause tearing of vessels, leading to a hemorrhagic stroke.
Microangiopathy is a disease of the microvessels, small blood vessels in the microcirculation. It can be contrasted to macroangiopathies such as atherosclerosis, where large and medium-sized arteries are primarily affected.
Cerebral edema is excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compression of brain tissue and blood vessels. Symptoms vary based on the location and extent of edema and generally include headaches, nausea, vomiting, seizures, drowsiness, visual disturbances, dizziness, and in severe cases, death.
Infarction is tissue death (necrosis) due to inadequate blood supply to the affected area. It may be caused by artery blockages, rupture, mechanical compression, or vasoconstriction. The resulting lesion is referred to as an infarct (from the Latin infarctus, "stuffed into").
Stroke is a medical condition in which poor blood flow to a part of the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.
Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds, subarachnoid bleeds, epidural bleeds, and subdural bleeds.
In haemodynamics, the body must respond to physical activities, external temperature, and other factors by homeostatically adjusting its blood flow to deliver nutrients such as oxygen and glucose to stressed tissues and allow them to function. Haemodynamic response (HR) allows the rapid delivery of blood to active neuronal tissues. The brain consumes large amounts of energy but does not have a reservoir of stored energy substrates. Since higher processes in the brain occur almost constantly, cerebral blood flow is essential for the maintenance of neurons, astrocytes, and other cells of the brain. This coupling between neuronal activity and blood flow is also referred to as neurovascular coupling.
Moyamoya disease is a disease in which certain arteries in the brain are constricted. Blood flow is blocked by constriction and blood clots (thrombosis). A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are small, weak, and prone to bleeding, aneurysm and thrombosis. On conventional angiography, these collateral vessels have the appearance of a "puff of smoke", described as moyamoya (もやもや) in Japanese.
Cerebral amyloid angiopathy (CAA) is a form of angiopathy in which amyloid beta peptide deposits in the walls of small to medium blood vessels of the central nervous system and meninges. The term congophilic is sometimes used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after staining with Congo red. The amyloid material is only found in the brain and as such the disease is not related to other forms of amyloidosis.
A perivascular space, also known as a Virchow–Robin space, is a fluid-filled space surrounding certain blood vessels in several organs, including the brain, potentially having an immunological function, but more broadly a dispersive role for neural and blood-derived messengers. The brain pia mater is reflected from the surface of the brain onto the surface of blood vessels in the subarachnoid space. In the brain, perivascular cuffs are regions of leukocyte aggregation in the perivascular spaces, usually found in patients with viral encephalitis.
Intracerebral hemorrhage (ICH), also known as hemorrhagic stroke, is a sudden bleeding into the tissues of the brain, into its ventricles, or into both. An ICH is a type of bleeding within the skull and one kind of stroke. Symptoms can vary dramatically depending on the severity, acuity, and location (anatomically) but can include headache, one-sided weakness, numbness, tingling, or paralysis, speech problems, vision or hearing problems, memory loss, attention problems, coordination problems, balance problems, dizziness or lightheadedness or vertigo, nausea/vomiting, seizures, decreased level of consciousness or total loss of consciousness, neck stiffness, and fever.
Intraparenchymal hemorrhage is one form of intracerebral bleeding in which there is bleeding within brain parenchyma. The other form is intraventricular hemorrhage).
Brain ischemia is a condition in which there is insufficient bloodflow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus leads to the death of brain tissue or cerebral infarction/ischemic stroke. It is a sub-type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage.
Vertebral artery dissection (VAD) is a flap-like tear of the inner lining of the vertebral artery, which is located in the neck and supplies blood to the brain. After the tear, blood enters the arterial wall and forms a blood clot, thickening the artery wall and often impeding blood flow. The symptoms of vertebral artery dissection include head and neck pain and intermittent or permanent stroke symptoms such as difficulty speaking, impaired coordination, and visual loss. It is usually diagnosed with a contrast-enhanced CT or MRI scan.
A hemorrhagic infarct is determined when hemorrhage is present around an area of infarction. Simply stated, an infarction is an area of dead tissue or necrosis. When blood escapes outside of the vessel (extravasation) and re-perfuses back into the tissue surrounding the infarction, the infarction is then termed a hemorrhagic infarct (infarction). Hemorrhagic infarcts can occur in any region of the body, such as the head, trunk and abdomen-pelvic regions, typically arising from their arterial blood supply being interrupted by a blockage or compression of an artery.
Charcot–Bouchard aneurysms are aneurysms of the brain vasculature which occur in small blood vessels. Charcot–Bouchard aneurysms are most often located in the lenticulostriate vessels of the basal ganglia and are associated with chronic hypertension. Charcot–Bouchard aneurysms are a common cause of cerebral hemorrhage. Charcot–Bouchard aneurysm rupture might be linked to senile plaque formation in the Alzheimer's disease.
Hereditary cystatin C amyloid angiopathy (HCCAA) is a rare, fatal type of hereditary cerebral amyloid angiopathy found almost exclusively in Iceland. A mutation in the protein cystatin C leads to amyloid dispositions in arteries in the brain, resulting in repeated brain hemorrhages.
Cerebral atherosclerosis is a type of atherosclerosis where build-up of plaque in the blood vessels of the brain occurs. Some of the main components of the plaques are connective tissue, extracellular matrix, including collagen, proteoglycans, fibronectin, and elastic fibers; crystalline cholesterol, cholesteryl esters, and phospholipids; cells such as monocyte derived macrophages, T-lymphocytes, and smooth muscle cells. The plaque that builds up can lead to further complications such as stroke, as the plaque disrupts blood flow within the intracranial arterioles. This causes the downstream sections of the brain that would normally be supplied by the blocked artery to suffer from ischemia. Diagnosis of the disease is normally done through imaging technology such as angiograms or magnetic resonance imaging. The risk of cerebral atherosclerosis and its associated diseases appears to increase with increasing age; however there are numerous factors that can be controlled in attempt to lessen risk.
David John Werring is a British physician, neurologist, and academic specialising in stroke. He is professor of Neurology at the UCL Queen Square Institute of Neurology and current head of Stroke Research Centre and the department of Brain Repair & Rehabilitation at UCL.
The Boston criteria version 2.0 is a set of guidelines designed to diagnose cerebral amyloid angiopathy (CAA), a disease that affects small blood vessels in the brain, particularly those in the cortex and leptomeninges. Although the gold standard for diagnosis is histopathological examination, the Boston criteria provide clinicians with a probabilistic approach for diagnosis largely based on imaging characteristics.