Cerebrovascular diseases: Weakened, narrowed or dilated cerebral vessels? Causes and symptoms

Cerebrovascular diseases combine a wide group of diseases based on impaired brain function due to impeded blood supply.

Cerebrovascular diseases = cerebrovascular diseases. 
Cerebral - of or relating to the brain, vascular - of or relating to blood vessels. 
Abbreviated as CVD.

Brain vessels can be affected by several diseases. These can be congenital or acquired during life. They have been going on for a long time, but mostly acute.

The most well-known disease that causes a failure of brain function is a stroke. It is divided into several subtypes.

It is therefore a group of diseases affecting the flow of blood to and through the brain. As a result, cerebral vascular insufficiency will cause brain function to fail.

This is manifested by various symptoms, depending on the location, extent and rate of disruption of the blood supply to the brain cells.

Cerebrovascular diseases are among the most serious conditions.

They belong to the group of cardiovascular diseases.

This group also includes ischemic heart disease and myocardial infarction. The causes of these cardiovascular diseases and CVD are related, except for the location of the problem. There are a number of common risk factors behind their emergence.

FAQ:

What are cerebrovascular diseases?

What causes narrowed, dilated or weakened blood vessels?

What are the typical symptoms and what causes reduced blood supply?

How are these diseases treated?

A summarised factsheet on cerebral blood flow 

The brain - brain tissue must be constantly supplied with blood. Disruption of blood flow to the brain is immediately detected as a disorder of its function.

Why?

The brain, its nerve cells, require the two most important substances in order to function: oxygen and sugar. They serve as the main fuel.

Here are some interesting facts about brain consumption:

• it needs about 115 grams of sugar a day
• 100 grams of brain tissue requires about 5.5 mg of sugar
  • 75 mg per minute 
• 100 g mozgového tkaniva potrebuje asi 3,5 ml kyslíka
  • 50 ml O₂per minute for the entire brain
  • = 15 - 20% oxygen demand for the whole human body
• 50 - 60 ml of blood per 100 g of brain per minute
• about 750 ml of blood per minute flows through the brain at rest
  • with high brain activity, blood flow can increase by up to 50%
• vascular insufficiency (inadequate blood supply):
  • 2 - 8 seconds till the brain has consumed the oxygen
  • after 12 seconds without oxygen, cognitive impairment, collapse, and unconsciousness ensue
  • after 3 - 4 minutes irreversible brain damage begins
  • after 9 minutes without oxygen, brain survival is not possible
    • the exception is the state of hypothermia of the body, when the brain activity and consumption decrease

Two major paired arteries supply blood to the brain.

They are the vertebral artery and the internal carotid artery. They branch off and are connected in the brain to the so-called Circle of Willis, also called loop of Willis, cerebral arterial circle, and Willis polygon.

The Circle of Willis consistsconsists of 5 main arteries, extending from the carotid arteries and spinal arteries:

1. arteria cerebri anterior dx. et sin. - anterior cerebral artery, left and right
2. a. communicans anterior - anterior communicating artery
3. a. cerebri media dx. et sin. - middle cerebral artery, left and right
4. a. communicans posterior dx. et sin. - posterior communicating artery
5. a. cerebri posterior - posterior cerebral artery, branching off a. basilaris (basilar artery) which branches off vertebral arteries

These major arteries further branch into smaller ones.

The cerebral veins drain blood from the brain through a so-called complex sinus system. The veins are superficial and deep.

Gravity ensures the return of blood from the brain to the body, to the paired internal jugular vein.

The cerebral sinuses are stored in the dura mater.

Want to know more about cerebrovascular disease?
What causes it 
How doe sit manifest? 
What is the treatment? Can we prevent it? 
Read on.

Cerebrovascular diseases

Cerebrovascular diseases associate a wide range of diseases that are involved in cerebral circulatory disorders.

Therefore, they affect the blood vessels of the brain.

Most often, these are vessels damaged and narrowed due to atherosclerosis, causing thrombosis in the damaged vessel and closing off the vessel completely.

Another form is embolism, i.e. the introduction of a blood clot from another place in the body, e.g. from the heart.

The result is a stroke.

However, the issue of CVD does not end there. Other diseases with a different mechanism of origin should also be considered.

Cerebrovascular diseases also include:

• ischemic stroke
  • infarction
  • transient ischemic attack (TIA)
• hemorrhagic stroke
  • intracerebral hemorrhage
  • subarachnoid hemorrhage
  • intraventricular hemorrhage
• cerebral aneurysm
• venous thrombosis - vein thrombosis
• vascular malformation
  • arteriovenous malformations and venous malformations

Cerebrovascular diseases arise from a variety of causes. They are generally divided into congenital or acquired.

Congenital diseases are, for example...

The group of congenital patients is affected by genetic equipment, as in the case of arteriovenous malformations or CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy).

Arteriovenous malformations form a tangle of blood vessels, mixing arteries and veins. This connection is pathological, as the direct connection of the arteries and veins does not protect the low-pressure veins from the increased pressure in the arteries.

Risk of rupture and bleeding from malformation.

In some cases, they are lifelong unnoticed and asymptomatic. On the other hand, there are also those where the risk of a blood vessel ruptures increases every year.

The mentioned disease CADASIL (Cerebral Autosomal Dominant Arteriopathy) is caused by a mutation in genes and is an inherited disease. It can develop at a young age after the age of 30.

It is based on numerous infarcts of small cerebral arteries. They are caused by progressive hypertrophy of vascular wall smooth muscle cells.

This results in various difficulties, from intense migraines, through mental disorders, cognition, to several neurological problems. It is divided into three subtypes, which differ from each other.

The disease is often confused with other diseases, such as psychiatric disorders.

And then there is also the acquired form...

During our lives, we participate in the development of various diseases through poor lifestyle. Of course, genetic predisposition and heredity also have a certain relationship to their development.

Increasing age and natural wear and tear also contribute to them.

These are therefore factors that we cannot influence by our actions and those that can be influenced.

This is also why some risk factors are mentioned for CVDs:

• advanced age - with age, the risk of physiological wear and tear of the body increases
• being male - men are more at risk for cardiovascular disease overall
• heredity and family occurrence
• high blood cholesterol
• high blood pressure - hypertension, even at BP higher than 140/90 the risk of complications increases
• smoking - active and passive
• excessive alcohol intake
• diabetes - diabetes mellitus - vascular damage
• heart rhythm disorder due to the risk of thrombi and embolism
• being overweight and obesity - a generally increasing risk factor
• excess saturated fatty acids - fat in the diet
• lack of exercise and sedentary lifestyle
• injury and a higher risk of cerebral aneurysm

We can influence most of these factors during our lifetime = modifiable risk factors.
Healthy lifestyle = reduces the risk of vascular disease.

Atherosclerosis is a similar case.

In short, it occurs due to a build-up of plaque inside the lining of the artery wall. Fat and other components are pathologically stored in blood vessels. Over the years, this process causes a narrowing of the lumen of the blood vessels and narows the space for free blood flow.

The vascular wall is rigid, less elastic. This is also why high blood pressure develops. Hypertension is subsequently a risk factor that further pathologically affects the entire human body.

In addition to atherosclerosis and hypertension, thrombosis is also at risk.

Thrombosis, or the formation of blood clots, has a multifactorial cause as well.

Besides blood clotting disorder, damaged artery wall due to atherosclerosis also cause blood clots in the vessels.

Atherosclerosis + thrombosis = possible bloodlessness - ischemia or embolism.

Blood clots form in the heart, too. Examples of conditions causing thrombus formation are cardiac arrhythmia and heart valve disease.

The basic mechanism is impaired blood flow.

Furthermore, these conditions are at high risk for embolism.

An embolism is a condition in which a blood clot forms which is released elsewhere in the body. It then travels through the bloodstream and ends up in a smaller blood vessel.

The blood clot clogs the blood vessel, which results in the non-blood supply part of the embolisation, i.e. ischemia. When a cerebral artery becomes clogged, a form of ischemic stroke arises.

It is these clots that contribute to the development of a stroke due to the aforementioned cardiac arrhythmia or valve damage.

Besides being causes by blood, embolism can occur due to other foreign bodies in the blood. You can read more, for example, in the article Pulmonary embolism.

Another example is brain aneurysm, i.e.is a pathological or abnormal dilation or ballooning of the blood vessel. The dilated wall of the artery is weakened, which creates a risk of artery rupture and bleeding.

A weakened and dilated vascular wall can rupture, causing bleeding.

Subarachnoid hemorrhage is mostly caused by rupture of the intracranial aneurysm. It is a form of bleeding stroke.

Interesting is the percentage share of strokes:

1. 88 % arise from ischemia
2. 9% is bleeding into the brain tissue
3. 3% due to subarachnoid hemorrhage

What if the cause is unknown?

In cerebrovascular diseases, the cause of the outbreak may not always be known. This form of the disease is called idiopathic.

An example is Moyamoya disease.

It is a form of vasculitis that can have primary and secondary causes.

Insufficient blood supply to a part of the brain causes stenosis, i.e. narrowing of the artery. Also, minor bleeding is also caused by neurological issues.

That is how the disease got its name: in conventional angiography, these collateral vessels have the appearance of a "puff of smoke" which are called "moyamoya" in Japanese.

More on Moyamoya diease.

Another group are various cerebral vascular anomalies.

Table: Cerebrovascular anomalies

Table: cerebrovascular diseases

The symptoms of cerebrovascular disease are variable. They may not occur at all during one's lifetime.

However, as a result of insufficient blood supply (ischemia) various neurological symptoms arise: speech and cognitive disorders, paralysis, and loss of consciousness.

Bleeding is characterized by a sharp onset of neurological dysfunction.

The most serious complication of insufficient blood supply or bleeding is death.

In the case of transient ischemic attacks, the condition improves in several hours.
Transient - temporary ischemia of the brain = transient ischemic attack,or TIA.

The opposite of a transient condition is permanent brain damage due to bloodlessness = cerebral infarction.

Lacunar cerebral infarct = the area of ischemia is usually less than 1 cm. It occurs in a heart attack from the small cerebral arteries.

Cerebral infarction can be caused by thrombosis, atherosclerosis or embolism.

Cardioembolic stroke = asi 15 - 30 %. 
Lacunar stroke 15 - 30 %. 
Atherosclerotic stroke around 25 %. 
Cryptogenic stroke = with an unexplained cause about 20 - 40 %. 
Other causes of heart attacks about 5%. 
The ICD (International Classification of Diseases) code of cerebral infarction is I63. 

Manifestations of cardiovascular disease, or CVD, depend on the location, extent and rate of onset of complications. It also determines the state of current blood flow and collateral circulation.

Collateral circulation - simply put, it is a circular bypass, blood supply via another path.

Some symptpms of CVD include:

• severe and sudden pain - cephalalgia
  • in chronic headaches, it is characterised by a change in the intensity, character or location of the headache
• speech disorders and communication issues, dysarthria, aphasia
  • mispronunciations
  • incomprehensible speech, mumbling, word salad
  • the patient does not understand language
  • the patient understands language, but cannot express themselves
• behavioural disorder, confusion, disorientation
• weakness, inability to move the limb - paralysis
  • unilateral weakening/paralysis - hemiparesis/hemiplegia
  • weakness and partial loss of movement - paresis
  • complete loss of movement - paralysis - plegia
• weakening of facial muscles - facial droop or palsy
• sensitivity disorder - sensing through the skin, limbs, body parts
  • pain or heat perception disorder
  • paresthesias - unpleasant sensations, pins and needles, burning, feeling cold etc.
• visual impairment, loss of vision in one eye
• dizziness
• perception of sound - tinnitus
• balance problems, a pulling sensation to one side
• nausea, vomiting
• hypertension
• body cramps
• loss of consciousness
• respiratory arrest or death

Table: some symptoms according to cerebral artery disease

More information in the article on: Strokes.

Diagnosis is based on medical history, clinical symptoms, neurological examination. All of these methods will complement the examination using imaging techniques.

Early detection of a stroke is important. Early diagnosis is used with early treatment, which aims to eliminate the cause of the cerebral circulatory disorder.

The prognosis and the resulting health condition of the affected person and the present neurological deficit also depend on the speed of recognition of symptoms, through diagnosis to timely professional treatment.

There is an acronym used as a mnemonic to help detect and enhance responsiveness: FAST.

• F = facial drooping - drooping of one side of the face, eye and mouth, the sufferer is not able to smile
• A = arm weakness - upper limbs, sufferers are not able to lift their arms and keep them in a higher position, the inability to hold one arm up, there is one-sided paralysis of the body
• S = speech difficulties - the inability to speak or understand spoken language
• T = time - time is of essence, call an ambulance, check the time so that you'll know when the first symptoms appeared 

The medical history contains information gained from the subjective evaluation of the patient, based on medically relevant complaints., i.e. other diseases and family history, i.e. the occurrence of diseases in the family.

Next, a physical and neurological examination is performed.

The examination reveals whether there was a stroke. However, it is important to do certain examinations using imaging technologies to determine the exact cause.

Important imaging techniques include:

• CT + angiography, cerebral angiography
• MRI
• carotid ultrasound - Doppler, duplex ultrasonography

Also, there is ECG, monitoring of blood pressure and heart activity, and taking blood samples for laboratory examination. In case of unclear etiology (cause), cerebrospinal fluid (suspicion of infectious origin) is also analysed.

More information on other blood vessel diseases: 
Aortic diseases
Carotid artery stenosis
Superficial vein thrombophlebitis
Deep vein thrombosis
Postthrombotic syndrome
Chronic venous disease
Chronic venous insufficiency
Peripheral arterial disease

The course of the disease has no clear features.

There are diseases that are asymptomatic throughout life and do not complicate and worsen the condition.

In other cases, however, there is an abrupt onset with intense difficulties. They can result in severe neurological deficits and death or perception.

For example, the above mentioned temporary ischemia, i.e. blood supply insufficiency.

Transient ischemic attack, or TIA...

Temporary insufficient blood supply starts with a typical pattern of ischemia in the affected part of the brain, but then the issues subside within 24 hours as the brain tissue is supplied with blood again.

Another form is cerebral infarction, when the neurological deficit worsens and the difficulties progress within the first 24 to 72 hours.

On the other hand...

There are cases where the onset of the disease is abrupt with a severe neurological deficit. However, gradually the symptoms get milder and the neurological impairment is not up to such a level.

An example is the transfer of an embolus (blood clot) to a smaller cerebral artery.

So the course of a cerebrovascular disease (CVD) cannot be exactly determined. It depends on the location and extent of the damaged blood supply to the brain tissue as well as the state of the collateral circulation.

Of course, when neurological problems occur, early professional care + diagnosis and early treatment = the possibility of a smaller neurological deficit and a better prognosis.

There is a difference in children

In children, there are fewer disorders due to CVDs.

The main cause in adulthood is atherosclerosis which does not occur in childhood.

The cause is various congenital malformations of the cerebral vessels, as well as heart valve disease and thrombophilic conditions or infections.

They manifest themselves at neonatal age, but also in older children,depending on the main cause.

The ischemic stroke is most common in the first year of life. Subarachnoid hemorrhage in turn in adolescents.

The course of the disease may not be as clear as in adulthood. There are certain symptoms that may or may not directly indicate a stroke.

In childhood, CVD complications manifest themselves as:

• body cramps, cramps in certain body parts or throughout the whole body
• headaches
• in young children, excessive irritability or lethargy, or attenuation of mental functions
• high body temperature - fever above 38 °C and above
• nausea and vomiting
• vision disorders
• and other issues found in adults