A cerebrovascular disease known as a stroke is responsible for almost 50% of all neurological disorders and is the third most common cause of death worldwide, following cancer and heart disease.
The changes in the brain resulting from a disease of the blood vessels cause neurological impairments. As the brain relies on an uninterrupted supply of blood, even a brief interruption in blood flow to a specific region can result in brain damage. Prolonged blood flow disruption leads to ongoing neuronal cell death and results in an irreversible injury.
To diagnose brain damage caused by a cerebrovascular disease, medical professionals such as neurologists can employ radiological tests. Imaging techniques such as CT scans or MRI scans can offer a wealth of information about the impacted brain structures.
Furthermore, it is crucial to have a neurological examination conducted by a psychologist to complement the radiological tests. This can help uncover evidence that imaging techniques may not be able to detect, such as alterations in behavior. Both approaches are essential for a comprehensive and thorough diagnosis.
Stroke is a heterogeneous group of cerebrovascular disorders that result from a vascular mechanism causing brain injury. The use of neuroimaging techniques has increased stroke detection rates over the past few decades. Lifestyle choices are also a contributing factor to the rising incidence of strokes.
The primary risk factors for strokes are related to the accumulation of fats in blood vessels, their calcification, or loss of flexibility. These factors include hypertension, high cholesterol, diabetes, and tobacco use. The likelihood of experiencing a stroke is higher for individuals over the age of 60. Cerebrovascular accident (CVA) occurs when blood flow is interrupted in a specific region of the brain. The resulting lack of oxygen can lead to damage or death of brain tissue over time.
Cerebrovascular accidents (CVAs) typically present as painless and transient symptoms, making them difficult to diagnose. The manifestation of symptoms usually occurs on the opposite side of the body to the affected hemisphere. For instance, if there is reduced blood flow on the right side of the brain, the consequences tend to appear on the left half of the body. Typically, there is a loss of strength or numbness in one side of the body, including the face, arms, legs, and so on. An abrupt loss of vision, either partially or completely in one or both eyes, may also occur. Difficulty speaking or comprehending is another common symptom.
There are two primary classifications of strokes:
- Ischemic strokes: These strokes result from the blockage of an artery or, in rare cases, a vein. Approximately 87% of all strokes are ischemic.
- Hemorrhagic strokes: These strokes result from bleeding. Approximately 13% of all strokes are hemorrhagic.
Ischemic strokes
An ischemic stroke takes place when a blood vessel supplying the brain is obstructed, causing a disruption in blood flow to a section of the brain. As a result, brain cells and tissues begin to die within minutes due to insufficient oxygen and nutrients. Ischemic strokes can be divided into two categories:
- Thrombotic strokes: These are caused by the development of a blood clot within the blood vessels located in the brain.
- Embolic strokes: These are caused by a blood clot or plaque debris that forms elsewhere in the body and then travels through the bloodstream to one of the blood vessels in the brain.
A thrombotic stroke is caused by the formation of a blood clot or thrombus within an artery supplying blood to the brain. This type of stroke typically affects older individuals with high cholesterol, atherosclerosis, or diabetes. Symptoms may occur suddenly, often during sleep or early in the morning, or may develop gradually over several hours or days. Transient ischemic attacks (TIAs), also known as mini-strokes, may precede thrombotic strokes and serve as warning signs. Lacunar infarcts, another type of stroke, occur in small blood vessels in the brain and are often seen in individuals with diabetes or high blood pressure. The term “lacunar” derives from the Latin word for “hole” or “cavity.”
Embolic strokes are a type of ischemic stroke caused by a blood clot that forms in another part of the body and travels to the brain through the bloodstream, blocking a blood vessel in the brain. The clot may originate in the heart, typically due to a condition called atrial fibrillation, or in other parts of the body such as the carotid arteries in the neck or the aorta.
Embolic strokes can occur suddenly and without warning, often resulting in more severe symptoms than other types of ischemic strokes. The symptoms of an embolic stroke depend on the part of the brain that is affected and may include paralysis or weakness on one side of the body, difficulty speaking or understanding language, vision problems, and loss of coordination or balance.
Hemorrhagic strokes
Hemorrhagic strokes occur when a blood vessel that supplies the brain ruptures and causes bleeding. As a result, brain cells and tissues do not receive adequate oxygen and nutrients, and the pressure builds up in surrounding tissues, leading to irritation, swelling, and further brain damage. There are two main categories of hemorrhagic stroke:
- Intracerebral hemorrhage: This type of stroke occurs when bleeding happens from blood vessels inside the brain.
- Subarachnoid hemorrhage: This type of stroke occurs when bleeding takes place in the subarachnoid space, which is the area between the brain and the membranes that cover the brain.
Intracerebral hemorrhage is a type of hemorrhagic stroke that occurs when a blood vessel within the brain ruptures and bleeds into the brain tissue. This type of stroke is often associated with high blood pressure, and the bleeding can occur suddenly and rapidly without any warning signs. The bleeding can be severe enough to cause coma or death, and immediate medical attention is necessary to prevent further brain damage.
Subarachnoid hemorrhage occurs when bleeding happens in the subarachnoid space, which is between the brain and the membrane covering the brain called meninges. This type of hemorrhage is typically caused by an aneurysm or an arteriovenous malformation (AVM), but it can also be due to trauma.
An aneurysm is an abnormal, weakened area on an artery wall, which has a risk of rupturing. It can be present at birth or develop later in life due to factors such as high blood pressure or atherosclerosis. On the other hand, an AVM is a congenital condition where an abnormal tangle of arteries and veins is present, and it can be genetic or part of certain syndromes.
Recurrent strokes
Recurrent strokes refer to the occurrence of a second stroke in a person who has already experienced a prior stroke. It is estimated that approximately 1 in 4 individuals who have suffered a stroke will experience a recurrent stroke within 5 years after the first one. The risk of recurrence is highest in the immediate period following the initial stroke and decreases over time. The likelihood of severe disability and death increases with each recurrent stroke. Within 30 days of a first stroke, around 3% of individuals may have a second stroke, and approximately one-third may have a second stroke within 2 years.
Stroke and cognition
A stroke can impact the cognitive abilities of an individual, including their understanding, organization, and storage of information. This can result in a range of issues and challenges, and it is important to understand how these cognitive impairments can affect daily life. While this information is primarily aimed at those who have experienced a stroke, it can also be useful for their loved ones and caregivers.
What is cognition
Cognition refers to the mental processes and abilities involved in perceiving, processing, and retaining information. It includes functions such as attention, memory, language, perception, problem-solving, decision-making, and reasoning. These processes are controlled by different areas of the brain, and if one of these areas is damaged by a stroke, it can affect a person’s ability to perform these functions. For example, a stroke survivor may have difficulty with memory, attention, problem-solving, and decision-making, which can impact their daily life and ability to communicate with others.
Cognitive assessment
Upon admission to the hospital, a cognitive assessment will typically be conducted to identify any potential cognitive problems. However, some cognitive issues may not be immediately apparent and may only become noticeable after being discharged.
The assessment is typically conducted by a doctor, occupational therapist, or psychologist, and may involve answering questions or completing tasks to evaluate cognitive function. Although some questions or tasks may seem simple, it’s essential to complete the assessment as it can help the stroke team determine the most appropriate course of action to assist with recovery.
Types of cognitive problems after stroke
Different types of cognitive problems can arise after a stroke. These include difficulties with concentration, memory, planning and problem-solving, spatial neglect, apraxia (problems with controlling body movements), visual perception, anosognosia (confusion and denial), and agnosia (problems recognizing things). Each type of cognitive problem is diagnosed and treated in different ways. Your healthcare team can help you understand the specific cognitive problems you may be experiencing and the appropriate treatment plan to manage them.
References:
https://www.hopkinsmedicine.org/health/conditions-and-diseases/stroke/types-of-stroke