The brain is a highly complex organ divided into specialized regions, each responsible for a specific function. A stroke is a lack of blood supply to the brain and can damage particular areas, resulting in a variety of impairments involving movement, speech, integrative function, emotion and cognition. Strokes are the leading cause of disability in the United States, and impairment level depends upon stroke type, severity and location, according to The University of Maryland Medical Center.
Movement
Strokes, particularly located in movement-related areas of the brain, cause a myriad of movement impairments, for example, paralysis. Paralysis can abate over the course of weeks post-stroke, but hemiparesis, or the weakening of one half of the body remains. Despite muscular weakness, increased muscular tone, or hypertonia, occurs, making joints rigid and difficult to move. Lastly, spasticity is a common problem, characterized by involuntary muscle contraction in response to rapid movement of a limb. Overall, each type of movement impairment is caused by a lack of nerve signaling from the brain responsible for the production of movement, according to the University of Texas.
Speech
Difficulties speaking and retrieving words are common afflictions following a stroke, particularly within damage to the left hemisphere of the brain. The left temporal lobe houses Broca’s area, which is responsible for speech production, and Wernicke’s area for language perception and understanding. Speech articulation is also affected by strokes within the brainstem, an area that controls the muscles of speech, according to the University of Maryland Medical Center and the University of Ohio State University Medical Center.
Integrative Function
The ability to integrate sensory information within the brain is a very important function in order to react to your environment. For example, sensory information is used to plan movements like reaching out to pick up a cup of coffee. The parietal lobe is the site of sensory integration, and a stroke to this area can give rise to an affliction called visual neglect. Visual neglect is the inability to perceive your surroundings on the opposite side to the stroke location. Therefore, you would only see half of a clock, half of your face in a mirror and half of the your dinner on a plate, but you lack the ability to realize that you are only seeing half, according to Dartmouth College.
Emotion
A stroke can injure regions of the brain responsible for the regulation of emotion for example the amygdala, temporal lobe or frontal lobe. Damage to any of these areas leads to emotional outbursts, anxiety or depression, according to the University of California, San Francisco.
Cognition
Severe or repeated strokes can damage brain regions related to memory and cognition so much so that vascular dementia results. Vascular dementia is much like Alzheimer’s disease, and is caused by a lack of blood flow within the brain. Symptoms include absentmindedness, poor memory and difficulty problem solving, according to the University of California, San Francisco.
