Strokes: Warning Signs & Brain Function Impacts

What is a Stroke?

A stroke occurs when the blood flow to the cerebral arteries in the brain is disrupted, and some brain cells don’t get the oxygen and nutrients they need. The affected brain cells die and that area of the brain can’t function as it did when they were alive. The American Heart Association/American Stroke Association says that strokes are the #5 cause of death and a leading cause of disability in the United States.

As shown in the image below, with an Ischemic stroke (left), blood clot stops flow of blood to an area of the brain. With a Hemorrhagic stroke (right), blood leaks into brain tissue.

(Ischemic & Hemorrhagic Stroke Images: https://www.scientificanimations.com, CC BY-SA 4.0)

How Are People Affected by Stroke?

Left and Right Brain Hemispheres & Brain Functions

The right hemisphere of the brain controls the left side of the body, and the left hemisphere of the brain controls the right side of the body. For these reasons, if a stroke occurs in the right side of the brain, the left side of the body will be affected. Some functions are controlled by both hemispheres of the brain, and other functions are controlled by either the left or right hemisphere, as the infographic below demonstrates.

In summary, depending on which hemisphere of the brain a stroke occurs in, different functions may be impacted as follows:

Left Hemisphere of the Brain

the right side of the body, ie hand, arm, leg movements
language – spoken language and written language
reasoning and analytical skills, including mathematical and scientific functions & calculations

Right Hemisphere of the Brain

the left side of the body, ie hand, arm, leg movements
spatial orientation
artistic functions, creativity, and awareness, including music
insight

6 Regions of the Brain & Brain Functions

The left and right hemisphere of the brain are divided into 6 regions that each control different functions, as the infographic below demonstrates.

In summary, depending on which region and hemisphere a stroke occurs in, different functions may be affected as follows:

Frontal Region of the Brain

Personality, behaviour control
Speaking and writing abilities
Emotions and arousal
Intelligence
Ability to problem solve, plan, make decisions, put things in order, concentrate
Voluntary movements

Parietal Region of the Brain

Sensations – pain, touch, temperature and the ability to understand and interpret sensory information – size, colour, shape
Understanding space and distance
Mathematical calculations

Occipital Region of the Brain

Vision and interpreting what is seen

Cerebellum Region of the Brain

Balance and posture
Motor coordination (body movement)
Fine motor skills

Brain Stem Region of the Brain

Breathing
Heart rate control
Consciousness, alertness, wakefulness
Swallowing
Blood pressure
Sweating

Temporal Region of the Brain

Language skills and abilities
Hearing
Memory including long-term
Organization and planning
Behaviour and emotions

Warning Signs of Stroke

This video covers what a stroke is, the warning signs (symptoms) to watch out for, what to do in the event of a stroke, and how to reduce the risk of having a stroke.