Effects of Stroke
While the effects of stroke vary widely amongst individuals, there are some common threads that are observed across patients. Whether it be voluntary or involuntary actions, the brain itself controls the workings of the entire body [1]. The brain also controls different actions and parts of the body using different areas. This means that there is a specific part of the brain that controls our ability to speak, our ability to see, our ability to feel things on our skin, and so on.
Another important feature of the brain is that of contralateral control. All this means is that the left side of the brain controls the right side of the body and the right side of the brain controls the left side of the body. For example, whenever you move your left arm, you are using a specific part of your right brain to do so. These two features will become important as we discuss several effects that a stroke can have on daily functioning. Some helpful ways to deal with all of these effects will be discussed in the "Treatment of Stroke Effects" page.
Aphasia and Language Effects
Aphasia (also called dysphasia) is a medical term that refers to the loss of one's ability to either produce or understand speech because of brain damage. These are very common in stroke, since stroke typically leads to brain damage in a specific area of the brain. It occurs within 25 to 40 percent of stroke survivors [2]. There are three different types of aphasia:
- Broca's aphasia, or "expressive" aphasia, refers to the inability to speak properly. This occurs when an area on the left side of the brain known as Broca's area, which is responsible for language production, is the area affected by a stroke. Now, this doesn't mean that patients with Broca's aphasia cannot speak at all. What it really means is that the words that come out might be gibberish or not what they intended to say. For example, if someone with Broca's aphasia wanted to say "I put the towel on the table," they might end up saying "I rang the tower in the maple."
- Wernicke's aphasia, or "receptive" aphasia, refers to the inability to understand speech properly. This occurs when an area towards the side of the brain known as Wernicke's area, which is responsible for language comprehension, is the area affected by a stroke.
- Global aphasia refers to the inability to understand and produce speech. There can be many areas affected: the most common are when strokes lead to cell death in both Wernicke's and Broca's areas or the nerves that connect them [3].
It can be extremely difficult to live with any type of aphasia. Feel free to visit the "Treatment of Stroke Effects" section to read some advice about how to handle it effectively.
Apraxia: Trouble moving any part of the body
Apraxia is a medical term that refers to difficulty moving muscles anywhere on the body. Even though the reasons behind apraxia are not very well understood, we do know that there are many different types of apraxia. The names for these correspond to either the specific nature of the apraxia or the area of affected muscles. Here are just some of the specific subtypes of apraxia:
- Limb-kinetic apraxia : the inability to make subtle motor movements with large limbs such as arms or legs.
- Ideomotor apraxia : the inability to make the intended motor movement in response to a command.
- Ideational apraxia : the inability to do a series of subtle motor movements. This will affect activities such as getting dressed and eating.
- Oral apraxia : the inability to coordinate the movement of the jaw and other related muscles.
- Verbal apraxia : (also known as apraxia of speech) refers to any difficulty moving the facial muscles that are needed to speak [4].
Dysarthria: "slurred" speech
Dysarthria refers to "mumbled" speech that is typically caused by a limited range of movement for the lips, mouth and tongue. There are even rare cases when vocal inflection and intonation can change as well. [5]
Differences between Broca's aphasia, facial apraxia, and dysarthria
All of these effects that have been mentioned before are easily confused, even amongst people familiar with them. Hopefully the table below will help you differentiate between these similar terms.
| Stroke effect | Broca's Aphasia | Oral and Verbal apraxia | Dysarthria |
|---|---|---|---|
| Definition | Inability to produce intended speech | Inability to correctly move facial muscles necessary for speech | "Slurred" speech due to limited mouth movement as well as lips and tongue |
| Disorder type | Language disorder | Muscle disorder without muscle weakness | Muscle disorder with muscle weakness |
Dysphagia: Difficulty swallowing
This swallowing disorder is fairly common in most stroke patients, and disappears within a matter of weeks. However, there are some cases where dysphagia can become a permanent effect of stroke [6]. Please consult your healthcare team about how to approach this problem, and, if you do not have access to one, please begin by consulting this guide from the American Stroke Association.
Vision Changes
It is possible that a stroke can affect a person's vision. Since the visual system is complex, there can be several possible affected brain areas. The area that is most commonly affected is the occipital lobe , the area at the back of the brain that helps to organize and interpret visual information coming from the eye. Some common symptoms are double or blurry vision, partial or complete loss of a visual field, and even complete blindness if the damage is extensive enough [7].
Here are two terms that describe some of the most common visual change symptoms:
- Spatial inattention: This term refers to not paying attention to the side of the body affected by the stroke. For example, if someone asks the patient to copy a picture of a house, they may only copy one side while neglecting to draw the other side. Therefore, It is sometimes known as hemispheric neglect.
- Visual midline shift: In this disturbance, everything that once appeared level will now appear titled. This will affect the person's balance and will need to be addressed using rehabilitation [8].
Physical Effects
Depending on the brain region that is affected, physical effects from stroke can vary. It may be a lot harder to walk, communicate and just do everyday activities. These physical effects, as well as their duration, vary from patient to patient. There will sometimes be random muscle spasms (known as spasticity), which can be painful and may seriously interfere with everyday life.
Hemiparesis is a term that describes weakness or paralysis of one particular side of the body. For example, if one experiences a stroke on the left side of their brain, it is possible that they experience hemiparesis on the right side of their body (the brain exhibits contralateral control, as discussed in the beginning of this page).
Seizures are also common after experiencing a stroke, especially if the affected area is part of the cerebrum, another name for the cerebral cortex. Incontinence is another extremely common effect of stroke and involves the inability to control going to the bathroom. But, one of the most common complaints of all is that of sleep disturbance. There are many other common side effects such as pain, the dropping of the foot, and the clawing of the hand.
The best way to improve all of these is through physical rehabilitation. It may take from the order of weeks to years to regain normal functioning in some of these areas, but it will drastically improve pain management. More educational content on this can be found in the "Treatment of stroke effects" page, but it is not a substitute for medical advice. Please seek a healthcare professional to ensure that the rehabilitation needs are suited for each individual case.
Cognitive Effects
Similar to the physical effects, the cognitive effects of stroke depend on the areas affected. Here are two of the most common cognitive effects that occur after stroke:
- Vascular dementia is a type of memory loss that is mostly associated with left-hemisphere stroke near the front of the brain. Vascular dementia impacts the ability to make decisions, plan ahead, make judgments, and the ability to reason [9].
- Memory loss is a more general term and can be vague in a lot of cases. There are some cases where memory loss is associated with getting older, but a stroke can also directly cause memory loss.
References
[1] https://www.stroke.org/en/about-stroke/effects-of-stroke
[4] https://www.ninds.nih.gov/Disorders/All-Disorders/Apraxia-Information-Page
[5] https://cohenspeech.com/services/aphonia-apraxia/
[6] González-Fernández M, Ottenstein L, Atanelov L, Christian AB. Dysphagia after Stroke: an Overview. Curr Phys Med Rehabil Rep. 2013;1(3):187-196. doi:10.1007/s40141-013-0017-y
[7] https://www.rnib.org.uk/eye-health/eye-conditions/stroke-related-eye-conditions