Difference in Strokes When Right-Handed vs. Left-Handed

Strokes affect different parts of the brain depending on where the blood flow disruption occurs. A stroke on the right side of the brain can produce symptoms that are different than a stroke on the left side of the brain. Similarly, a stroke may affect you differently if you are left-handed vs. right-handed.

This article reviews the main differences between strokes in people that are right-handed vs. people that are left-handed.

Your Handedness

Your dominant hand is the hand that you prefer to use for tasks that require coordination, particularly handwriting. Most people also have a hand preference in sports such as tennis, baseball, ​and football. Some people may even notice that one foot is dominant (it is on the same side of the body as the dominant hand).

About 10% of the population is born left-handed. Usually, parents can tell if a child is left-handed by around the age of 14-18 months, although some babies demonstrate hand preference even earlier. Historically, a variety of myths from just about every culture have deemed left-handedness as evil or inferior to right-handedness.

However, with the advancement of medical science, it is currently well-recognized in most parts of the world that neither left-handedness nor right-handedness is inferior or superior to the other. Believe it or not — this revelation is less than 70 years old.

The Language Center of the Brain

The vast majority of right-handed patients as well as approximately 70% of the left-handed patients have their language center located in the left hemisphere. The other 30% of left-handed patients process language on the right or in both hemispheres.

There are several regions in the brain that work together to control language function. The best understood are the Broca’s area and the Wernicke’s area, both located on the dominant side of the brain. The Broca’s area allows us to produce fluent speech while the Wernicke’s area allows us to understand the meaning of the language that we speak and hear.

Stroke and Right-Handedness or Left-Handedness

Neurologists usually ask if you are right-handed or left-handed during a neurological evaluation. The reason for this is that any problem that affects the brain manifests differently depending on whether you are right-handed or left-handed.

A stroke of the dominant frontal lobe or the dominant temporal lobe can cause a condition called aphasia, which is a serious disturbance of speech and communication.

But another important brain function is controlled by either the right side of your brain or the left side of your brain depending on your handedness. This is a much more subtle function called visual spatial perception.

Visual spatial perception is your awareness of the position of both sides of your environment in relation to your body. Visual spatial perception is controlled by a region in your brain located in the non-dominant hemisphere.

A stroke involving certain regions of the non-dominant cerebral cortex can cause a condition called hemiagnosia, which is a diminished awareness of one side of your body or a deficit in the perception of one side of your surroundings, described as hemispatial neglect. If you have a stroke in the sensory portion of your non-dominant cerebral cortex, this serious handicap can result.

Left-Handedness and Weakness After a Stroke

The motor portion of one side of your brain controls the movements of the opposite side of your body. If you are left-handed, a stroke in the right cortical or subcortical motor region of the brain can cause weakness of your dominant left arm and leg. This would be a significant problem for you because you depend on your dominant side to carry out intricate movements.

If you are left-handed, a stroke on the left side of your brain would affect the non-dominant right side of your body. You can more easily adapt to weakness on the non-dominant side of your body because most of the time your dominant side can take over. However, a non-dominant stroke can still have a significant effect.

A Word From Verywell

Your whole brain works together as a highly sophisticated machine. The functions of language and spatial perception are each highly concentrated on opposite sides of the brain.

Interestingly, your left- or right-hand dominance reflects the organization of your brain. Your hand preference provides a clue to your medical team about which side of your brain is affected by a stroke. This is one of the reasons you may experience a stroke differently than someone else who has had a stroke.

Recovery after a stroke takes time and usually requires post-stroke rehabilitation therapy, which helps in regaining physical and cognitive abilities after a stroke.