While strokes are the leading cause of death worldwide, not all incidents result in death. The condition occurs when blood supply to part of the brain is disrupted, causing dizziness, weakness, or paralysis on one side of the body. Your handedness – the preference for using one hadn’t over another – will usually reflect the organisation of the brain. This right or left hand dominance could determine the outcome of an acute stroke incident, as it can provide clues about which side of your brain could be affected.
Hand dominance has been cited as an important factor in the performance of motor skills, with the dominant hand being used for daily and recreational activities.
It is estimated as little as ten percent of the population is left-handed, yet very little is known about what being left- or right-handed means for brain function.
Researchers have observed stroke sufferers have their dominant hand affected by an incident.
One study in particular, found that right-handed patients who have a stroke on the left side of the brain tend to recover their speaking abilities more slowly than left-handers.
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Doctor Athwal, Consultant Neurologist at the Wellington Hospital Stroke Rehabilitation Centre, said: “Any problem that affects the brain – including stroke – may manifest differently depending on handedness.
“Neurologists usually ask people whether they are right or left-handed to better understand the effects of a stroke.
“Handedness reflects which side of an individual’s brain contains the dominant hemisphere and which side the non-dominant hemisphere.
“In a right-handed person, for example, the dominant hemisphere is on the left.”
Furthermore, some studies have found that a stroke will produce different symptoms depending on whether it occurs on the left or right side of the brain.
The vast majority of right-handed patients and well as 70 percent of left-handed patients have their language centre located in the in the left hemisphere of their brain, the other 10 percent of left-handed patients use both hemispheres to control language function.
Doctor Athwal explained: “One important difference between right and left sides is language function. This is the ability to express and understand language in all its forms, not just speaking.
“In nearly all right-handed people, and in about half of left-handed people, the language centre is on the left, in an area called the left temporal lobe.
“A stoke here can affect the ability to understand or express language, or both. Because language is such an important function a stroke on the left side of the brain can have a greater impacts than one on the right.”
When a stroke affects the sensory portion of the non-cerebral cortex, injury can result in handicap.
An acute injury to one side of the brain can cause patients to ignore information from the opposite side.
Therefore, when a stroke occurs on the right-side of the brain, recovering patients may miss seeing food on the left side of their plate.
Doctor Athwal added: “The right side of the brain tends to be more specialised for spatial perception. Damage to the right hemisphere can cause a phenomenon called neglect, also known as hemiagnosia.
“In this condition there is a reduced attention and perception of one side of the surrounding or one side of the body.
“This typically affects the left side of the body from right hemisphere damage. Neglect can affect how severe the stroke effects are and how quickly the person recovers.”
While neuroscientists understand that injuries manifest differently on each side of the brain, they have yet to decipher how different brain arrangement of the brain networks could affects how well people recover from spatial neglect.