WHAT ARE THE CONSEQUENCES OF A STROKE? - NEUROPSYCHOLOGY

In this article, we are going to explain the possible consequences of a stroke, a fairly frequent phenomenon that can have serious effects on health and lifestyle.

According to the National Stroke Association, every 40 seconds a stroke occurs somewhere in the world. And there are approximately 800,000 attacks a year, of which 137,000 die due to the spill.

It is also called a "stroke" or "cerebrovascular accident," and it occurs when blood flow to an area of the brain stops. As a result, brain cells are left without oxygen and therefore die.

In this way, those skills that are associated with the affected brain areas will be affected, so it must be diagnosed and treated as urgently as possible.

Currently there are treatments that can reduce the injuries caused, the most important thing being to quickly recognize the symptoms and go to the hospital. If the patient is treated within the first hour after the stroke, many negative consequences can be prevented.

How do they affect strokes?

Although they damage the brain, strokes can affect the entire body. They can be more or less serious, harming the life of the person to a greater or lesser extent.

The effects include different degrees of muscle weakness or paralysis, speech problems, visual difficulties, balance, motor coordination, numbness of certain parts of the body, behavioral and cognitive changes, etc.

Some manage to fully recover from strokes, although most are left with some kind of sequel.

The consequences of a stroke present a wide variety of clinical signs and symptoms. Disability will vary according to the degree of neurological recovery, the place of injury, the patient's previous state of health and the support systems in place.

Risk factor's

In addition, there are risk factors that can make a person more prone to have a stroke, factors that can be modifiable and others not. Some of the risk factors are: high cholesterol, being overweight and lack of physical activity, tobacco use, hypertension, suffering from diabetes, having already suffered another stroke or transient ischemic attack or suffering from cardiovascular disease.

Having high cholesterol causes it to begin to accumulate on the walls of the arteries, blocking the passage of blood over time.

Being overweight predisposes other risk factors to appear since the circulatory system must use greater effort to function.

Tobacco causes hardening of the walls of the arteries, making the heart work harder, increasing blood pressure, and damaging the walls of the blood vessels.

Hypertension or high blood pressure damages the artery walls and increases the likelihood of clots forming in the blood causing the stroke.

Diabetes causes changes in the blood vessels that are harmful, and the stroke is also more serious if the blood glucose level is high at that time.

Other factors would be being over 55, male, race, and family history.

The consequences of a stroke can be classified according to the location of the damage and according to the cerebral hemisphere where it is located.

Consequences depending on the location of the damage

The first step after a stroke is to locate the injury. There are certain types of seizures that tend to occur in specific areas of the brain.

Its effect will vary by person, location, severity, and number of spills. When a specific area of the brain is damaged, a specific and special function that it is responsible for is affected, so that the person ceases to have optimal functioning in that activity.

However, even if there are certain damaged areas, it is important to know that the brain acts in an integrated way. Any simple activity activates our entire nervous system. For this reason, any injury will affect our brain function as a whole.

Causing an interruption of blood flow in the carotid or anterior circulation, this type of effusion usually manifests with hemiparesis or hemiplegia. The first consists of a reduction in muscle strength only on one side of the body, the side opposite to the damaged cerebral hemisphere. The second, on the other hand, refers to total paralysis on one side of the body.

A sensory or visual field loss may also appear (called hemianopia), which means that we can only see half of our visual field, being "blind" to the other half.

The middle cerebral artery is the one most commonly involved in strokes, while the anterior cerebral artery is less (affected in less than 3% of all strokes). This occurs because the middle cerebral artery supplies two-thirds of the surface of each hemisphere.

Let's talk a little about the consequences that strokes have in each of them:

- Middle cerebral artery (MCA)

It involves areas such as the primary motor cortex, sensory areas of the face and upper extremities, and Broca's and Wernicke's areas (typical associated with language).

Additional symptoms will depend on in which of the two hemispheres the lesion is located. It also influences which of the two subdivisions (upper or M1, or lower or M2) the lesion is located. The main ones are:

Hemiparesis or hemiplegia: behaviorally manifested by significant coordination and balance problems, as the "strong" half of the body pulls and drags the "weak". In this way, the affected person may have notable difficulties sitting, getting up or walking.
Sensory loss
Hemianopia: lack of vision or blindness of only one visual field.
Aphasia (if the left hemisphere is damaged) that includes a set of different impairments of language, such as its production or expression or its understanding when listening or reading it. In addition, it is due to lesions in brain areas that affect language.
Visual perceptual deficits if the right hemisphere is damaged.

- Anterior cerebral artery (ACA)

It has the following consequences:

Weakness or loss of sensation on the side of the body opposite to the brain injury, affecting the lower extremities more.
Urinary incontinence
Paratonic stiffness: difficulties in moving a limb quickly, either in flexion or in extension, and that does not occur when the movement is performed slowly.
Transcortical Motor Aphasia (if it is in the left hemisphere).
Gait apraxia: problems executing the necessary movements to walk correctly, without having muscle problems or paralysis.

- Vertebrobasilar circulation

The vertebrobasilar circulation is the one that supplies the medial temporal lobes, occipitals, brainstem, and cerebellum. The consequences of a spill in these circuits depend on specific structures and are very varied:

Vertigo.
Nausea and vomiting.
Headaches.
Alterations in consciousness, so that they can go into a coma.
Ocular deviations and deficits, such as nystagmus or involuntary eye spasms.
Dysarthria (problems articulating sounds due to brain injuries that control the movements of the phonatory organs).
Diplopia (see double)
Paresthesia or numbness of the face
Motor disorders such as hemiparesis or quadriparesis.
Ataxia or lack of muscle control of the extremities.
Hearing loss
Loss of sensation.
Dysphagia or swallowing problems: sometimes these patients can have difficulty eating, which causes them to lose a lot of weight and even reach states of malnutrition. It is necessary to control that the affected person does not inhale food, choke, or even stay food on the affected side of the mouth. This is seen more in those patients who have a paralyzed side of the tongue or lack of sensation (Caregivers Library, 2016).
Cardiac arrhythmias or respiratory irregularities (associated with effusions in the basilar artery).
Sudden fall crisis or "drop attacks": it is a sudden fall without cause (apparently) while the person is walking or standing.
Hemianopia, memory loss (if the damage is in the medial temporal area), alexia (or inability to read) being able to write, prosopagnosia or condition in which faces cannot be recognized, cortical blindness, etc. They are typical consequences of effusions in the Posterior Cerebral Artery (PCA).

Consequences according to each cerebral hemisphere

It is important to know that normally and in most functions, one hemisphere of the brain will control the opposite side of the body. Therefore, if a stroke involves the right side of the brain, it will cause neurological problems on the left side of the body.

Therefore, depending on the affected hemisphere, all or some of these functions may be affected:

-Language and speech

-View

-Movement and perceptibility

-Perception and orientation of the environment

-Cognitive functions

-Emotional control

-Bladder and bowel control

-Capacity for personal care

-Sexual ability.

- Right hemisphere affected

The right hemisphere participates in the behaviors learned from voluntary initiation, perception and spatial orientation, planning, etc. The consequences of having a spill that covers this area can be:

One-sided spatial neglect

It occurs between 22% and 46% of patients with right hemisphere involvement. It manifests itself in that the patient ignores only one side of his body, as if it did not exist. For example, you only shave, dress, or style your hair on one side of the body; Either eat only half of the food plate or draw half of the objects. However, this condition recovers in an average of 9 weeks.

Anosognosia

It means that there is a lack of awareness about the disease or condition itself, that is, the patient does not feel that he has any problem. It is important in this type of patients that the professional let them know their deficits in order to encourage them to collaborate with the treatment.

Emotional disturbances

Such as indifference, apathy, lack of motivation, impulsiveness, or emotional lability. It is normal that after a stroke it is more difficult to control your own emotions.

In the group of patients who are normally unaware of their own disease, the emotional disturbances are more due to problems with brain function itself.

Communication problems

They have no problem producing language or understanding it. Rather, it is that they cannot use language skills adequately in their pragmatic component. It refers to interpreting the linguistic content through intonation, metaphors, ironies… it does not respect conversation turns, etc.

- Left hemisphere affected

This hemisphere is primarily associated with the learning and use of language in most people. The consequences of an attack in this area are:

Aphasias: covering different deficits in understanding, expression of language, reading or writing.
Apraxia : trouble carrying out voluntary movements despite having adequate strength, mobility, coordination, and understanding. There are different types, as with aphasias, such as ideomotor, constructive, speech…
Emotional disorders: such as depression, which occurs in 50% of patients after a stroke, especially if the damage occupies frontal areas. Anger and frustration are also observed in a very common way, since those affected are often aware of their disabilities, and notice their change after the stroke.
Slow and cautious behaviors and movements .
Possible memory problems .

Lacunar infarcts

A lacunar infarct is an interruption of the blood flow in the small arteries that supply the brainstem and the medial and deep basal areas of the brain.

They are characterized by very small lesions distributed in different subcortical structures. They are highly associated with high blood pressure. If they are very small, this type of heart attack can be asymptomatic.

The most frequent (65%) occur in the lenticular nucleus (in the caudate nucleus of the brain), especially in the putamen,

Consequences of lacunar infarcts:

Pure motor hemiparesis: weakness on one side of the face, arm and leg (without any sensory symptoms).
Pure sensory effusion: sensory symptoms only in one half of the body (without hemiparesis).
Dysarthria, dysphagia, weakness on one side of the face or tongue, motor clumsiness in one hand.
Ataxic hemiparesis, a syndrome that occurs in 87% of lacunar infarcts. It is characterized by both incoordination and weakness in one half of the body, mainly in the legs.

Other cognitive disorders

After a stroke, various cognitive functions can be altered, such as planning, problem solving, following instructions, decision making, attention, concentration, memory, etc.

In addition, all these aspects can be worsened if the patient also has fatigue or tiredness and emotional problems such as anger, depression or anxiety.

Vascular cognitive impairment

Deficits associated with injuries that affect attention, executive function and processing speed, provided spatial orientation and memory remain intact.

Vascular dementia

Loss of cognitive functions that come from cerebrovascular diseases or cardiovascular pathologies, in which, in addition to the previous functions, memory and orientation are also lost. Someone with a stroke is 10 times more likely to develop dementia than someone who has not.

Fatigue

It is very frequent, occurring between 30% and 60% of survivors. It can be extended from 3 to 13 months after the spill. Fatigue or excessive tiredness arises as a result of the alterations due to the accident, and this carries other negative consequences.

It can be a very limiting symptom both on a physical and psychosocial level, affecting functional independence, being linked to disability and neuropsychological problems; and promoting institutionalization and mortality.

It seems that the time since the accident, its severity or the right or left side of the injury does not influence the onset of fatigue, although there is some evidence that the location of the damage may increase the risk of fatigue.

It should be taken into account for cognitive rehabilitation that these patients burn out quickly. Therefore, it is necessary to try to do short sessions or with many breaks and, little by little, increase their duration.

On the other hand, it must be understood that these patients can show great confusion. As we have mentioned, many do not know that they have deficits, but they slightly notice that there are things that have changed: now they feel pain, numbness, do not understand their surroundings, etc.

For this reason, it is essential that those affected know their situation, and are motivated by the family and professionals to collaborate with the treatment.

Effects of a stroke on the cerebellum

The cerebellum is located under the brain, at the back of the skull. It is part of the brain and its main function is to integrate the sensory pathways, through which it receives sensory information through the spinal cord, and the motor pathways, thus controlling action and movements.

This type of spill is less frequent and its common consequences include:

-Sickness

-Vomiting

-Headache

-Ataxia: difficulty in coordinating movements.

Effects of a brain stem stroke

The brainstem is located at the base of the brain above the spinal cord, and is made up of the midbrain, the pons, and the medulla oblongata.

It controls various functions such as breathing, heart rate regulation, and blood pressure, and controls the major nerves involved in eye movement, chewing, swallowing, and speaking. Effects that occur in these types of spills:

-Chew, swallow and speak