Cerebrovascular disease

Cerebrovascular disease, stroke or cerebrovascular accident (stroke) It is defined as the set of those transitory or definitive alterations in the functioning of one or more areas of the central nervous system, which appear suddenly as a consequence of a failure in the cerebral blood supply.

CVA is the third leading cause of death in the adult population of developed countries. Its immediate mortality is high and approximately 8-24% of cases die in the first 30 days, and between 25-38% in the first year. It is the leading cause of death in people over 80 years of age.

CVA is the pathology most frequently involved in the beginning of acute or progressive functional disability in the elderly. 55% of patients suffer some type of disability, of which 20% is severe. This compromises the quality of life of the elderly and constitutes the second cause of early institutionalization.

The frequency of strokes is about 200 cases per 100,000 inhabitants per year. The possibility of suffering a stroke increases exponentially with age, since its incidence is more than double for each successive decade above 55 years of age. It is a disease mainly of elderly people, since between 76% and 85% of people who suffer a stroke are over 65 years of age. It also predominates in the male sex. Although there may be a family predisposition to some of the causes that cause it, stroke itself is not hereditary.

Types of stroke

The types of stroke are very numerous, since depend on the following factors: nature, size and topography of the lesion, form of establishment or temporal profile, evolution, mechanism of production and etiology, and characteristics of the neuroimaging. Determining the type of stroke is crucial for establishing treatment and predicting its course. In general terms, strokes can be divided, depending on the nature of the injury, into two large groups: cerebral ischemia and cerebral hemorrhage.

Cerebral ischemia

It represents 80-85% of all strokes.

It is the result of a decrease in circulatory supply, which may be limited to a territory, called focal ischemia, or affect the entire brain, then called global ischemia.

Global cerebral ischemia

It occurs when the entire brain is affected simultaneously, by a very accentuated and rapid, secondary to hemodynamic failure due to different causes such as: acute myocardial infarction, severe arrhythmia, hypovolemic shock, cardiac arrest, critical carotid stenosis, etc. The injuries can be very serious and often bilateral. It is also called cerebral hypoxia.

Focal cerebral ischemia

It is the most common. It is divided into two large groups, according to the form of clinical presentation: transient ischemic attack (TIA) and cerebral infarction.

Transient ischemic attack (TIA)

It is an episode of abrupt presentation, established in a few minutes, characterized by the appearance of a focal neurological deficit of the cerebral or retinal circulation, which evolves towards complete resolution in a period of time less than 24 hours.

Cerebral stroke

It supposes a neurological deficit lasting more than 24 hours, which is an expression of the brain cell death. It is important to know that the condition of the elderly person can change over time, since the cerebral infarction once established can remain stable, or it can progress and worsen during the first minutes or hours after onset, gradually, abruptly or fluctuatingly. which occurs in half of the patients; The lost functions can also recover in the 3 weeks following the onset of the clinic.

Stroke attacks can be divided into several types. So they exist:

• Thrombotic cerebral infarction: represents 14-40% of all cerebral infarcts; in the elderly they can represent about 60% of cases. It is the most frequent type in the elderly, as part of a generalized arteriosclerosis. It is characterized because it frequently begins during sleep, with an acute onset in hours or subacute in days, in patients with vascular risk factors such as arterial hypertension. Often there are previous TIAs in the same territory that later become infarcted.
• Cardioembolic cerebral infarction: in general, it represents 15-30% of them and accounts for 40% of stroke in the elderly. Emboli or clots are fundamentally of cardiac origin, favored by the existence of atrial fibrillation, mechanical valve prostheses, mitral or aortic valve disease, congestive heart failure, etc. The onset of the picture is very abrupt, in minutes or hours, frequently in wakefulness and with a maximum deficit from the beginning. Sometimes there is improvement shortly after onset. Hemorrhagic transformation is typical and often without new symptoms. Previous TIAs have occurred many times.
• Lacunar cerebral infarction: It is due to occlusions of small arterioles, generally due to an alteration of the vascular wall, mainly secondary to arterial hypertension or also due to diabetes. They can be asymptomatic, multiple or single, with typical symptoms. They are closely related to vascular dementia.

Cerebral haemorrhage

It represents 15-20% of all strokes.

Cerebral hemorrhage is produced by the rupture of a vascular wall with blood outlet to any of the following structures that give it its name. It is possible to differentiate between:

• Intracerebral hemorrhage or intraparenchymal hematoma: Also called stroke. Represents 15% of hemorrhages. Uncontrolled hypertension is its main cause.
• Subarachnoid hemorrhage: represents 5% cases. Its most common cause is a ruptured aneurysm, except for those caused by trauma.

Risk factors for stroke vary depending on the type of stroke. According to this, they can be classified as:

• Ischemic stroke: we can divide the risk factors into:

• • Not modifiable: Age, male sex; ethnicity (higher risk in Asian people), family factors and geographic location.
  • Potentially modifiable: diabetes mellitus, depending on the type and severity of it, so that it is greater in cases of prolonged evolution and with poor control; Left ventricular hypertrophy.
  • Modifiable: Hypertension, smoking, previous heart disease (especially atrial fibrillation), dyslipidemia.

The presence of previous TIAs acts as a “warning” or “marker” of global arteriosclerotic disease, and especially of brain involvement, and should be taken as a warning sign.

Cerebral haemorrhage

Risk factors are, above all, age, high blood pressure, chronic alcohol abuse, anticoagulation, the existence of previous strokes, and cocaine use.

The symptoms of stroke are determined by the location of the brain damage, the size of the lesion, and the etiology. Onset frequently takes one of the following clinical forms:

• Hemiparesis or total or partial paralysis that affects one side of the body. It presents a variable weakness in degree and extension, distributed over the face, upper and / or lower extremities of one half of the body. It is often accompanied by sensitive alterations, such as a tingling sensation, and dysarthria or clumsiness when speaking.
• Aphasia or difficulty understanding or expressing language.
• Transient monocular blindness, lasting seconds or a few minutes, called amaurosis fugax.
• Sudden instability with paresis and sensory disturbances of any limb, plus loss of vision in one or both visual hemifields, double vision, or vertigo.
• Sudden headache, of previously unknown intensity, often associated with physical exercise in subarachnoid hemorrhage. It may also be more moderate in intracerebral hemorrhage or extensive infarction, but there is no headache in small infarcts.
• In the elderly, atypical presentations such as acute confusional syndrome, falls, or urinary incontinence are not uncommon. Likewise, there is a higher incidence of loss of consciousness, seizures and metabolic disorders.

The treatment approach is mainly the prevention of modifiable risk factors: smoking cessation, diabetes and arterial hypertension control, atrial fibrillation and thrombosis control, etc.

At the acute stage, every stroke is a medical emergency. Early treatment of heart attacks has been shown to reduce sequelae and mortality. Today there are drugs that can dissolve thrombi or clots (fibrinolytic drugs), but that must be administered in the first hours and by neurologists who are experts in stroke. Urgency in treatment is essential to protect the brain. Other treatments are antiplatelet drugs (make it difficult to form thrombi) and anticoagulants (prevent the blood from clotting).

Sometimes surgery may be indicated, removing the atheroma plaque or dilating the artery (angioplasty). In hemorrhagic strokes due to malformations and aneurysms, the ideal treatment is embolization with substances that plug the ruptured arteries.

However, once the injuries are established, the treatment and rehabilitation of neurological deficits will depend on their type, location and intensity.