Since multiple brain regions are involved in different body functions, damages to specific areas of the brain after stroke leave the victim with several impairments. Neuropsychologists’ evaluation of stroke is based on the general differences between the brain’s left and right hemispheres. Each side of the brain influences different functions differently. The left side of the brain does process information differently from the right side.
In most cases, stroke affects one side of the brain. Movement and sensation for one side of the body are controlled by the opposite side of the brain. This is why left-sided stroke affects the right side of the body and right-sided stroke affects the left side of the body. Some stroke-led impairments are typical to right-sided stroke while some to left-sided stroke. There are certain stroke-led problems that are common to either side. These common symptoms include reduced attention, depression, reduced short-term memory and weakness on one side.
Whether a stroke has affected the front or back of the brain is also important to consider. Stroke affecting the front of the brain tends to affect the ability to recall verbs while stroke that occurs in the back of the brain may cause problems recalling nouns and making sense of what eyes and other senses perceive.
In most people, the left side of the brain controls the ability to speak and understand language. However, in some left-handed people, language is controlled by the right side of the brain and awareness by the left side of the brain. Establishing the location of stroke (left or right, front or back) holds importance in stroke rehabilitation program. Left-handed people tend to recover better from language problems while right-brain stroke patients may have poorer outcomes.
The left side of the brain deals with analyzing things sequentially and putting information in order. The left hemisphere handles details for reading and writing and is more responsible for positive emotions like joy. This justifies why people with left-sided strokes may experience trouble with skilled movements and speech. Common impairments proceeding left-sided stroke include Paralysis of the right side of the body, Aphasia, Apraxia, neglect of the right side, memory issues and slow, cautious and compulsive behavior.
The right side of the brain pulls information together, handles new information and is more responsible for negative feelings like anxiety. This is why about 98% of right-handed stroke survivors face significant problem with language and speech. They may encounter problems with the melody in speech and confusion.
Right-sided Stroke affects the left side of the body. Common impairments proceeding right-sided stroke include Anosognosia (a deficit of self-awareness), Anosodiaphoria, Visual Spatial Dysfunction, brief attention span, Hemispatial Neglect and social misperception (with trouble interpreting nuance, body language, and nonverbal clues).