Stroke-Related Cognitive Impairment
Stroke is a leading cause of death in the USA. A stroke can affect any part of the brain. Strokes are classified as ischemic or hemorrhagic.
A Transient Ischemic Attack (TIA) is a temporary focal neurologic deficit of presumed vascular cause that does not result in neuroimaging evidence of infarction or resolving within 24 hours.
Hemorrhagic stroke results from non-traumatic bleeding into the brain and is classified by the location: intracerebral, intraventricular, subarachnoid, subdural, or epidural
Cognitive problems happen because of damage to the brain. Different parts of the brain control different aspects of thinking skills. If one of the parts of the brain that controls cognition is damaged by a stroke, then this can affect you or your loved one’s ability to do certain things. If cognition has been negatively affected, then you or your loved one may find it difficult to concentrate or remember certain things. You or your loved one may also find it difficult to understand how to do something or know how to respond to what’s going on around you.
The complications that can occur after a frontal lobe stroke fall into four main categories. If you or a loved one has experienced a frontal lobe stroke, you may experience any combination of these effects.
Speech and language problems: comprehension difficulty or fluency difficulty
Cognitive decline: This may include a lack of initiative, mood changes, and inattentiveness. This can also include difficulty solving problems (goal-directed behavior) in different realms of cognition including linguistic, constructive, logical, and reasoning.
Behavior and personality changes: apathy, disinhibition, irritability, carelessness, lack of motivation, inappropriate comments, and/or impulsivity
Muscle weakness: ataxia or dysphagia
The temporal lobe is particularly important in language perception, memory, and hearing. There are a number of stroke-induced changes that are closely linked with the temporal lobe.
This can include:
Loss of short- or long-term memory
Fits of rage
Violent or aggressive behavior
Lack of interest
Abnormally enhanced sexuality
The parietal lobes are important regions of the brain that are critical in the perception of self, and the ability to feel our surroundings. A parietal lobe stroke may cause a loss of sensation affecting one side of the face, arm or leg. The parietal lobe is also involved in language function and analytical thinking. For most people, the left hemisphere of the parietal lobe is the language center of the brain, while the right hemisphere is responsible for cognition, calculation, and spatial orientation
With a right-sided parietal lobe stroke, there may be:
Abnormal sensations on the left side of the body
Inability to see out of the lower left quadrant of each eye
Spatial disorientation, including problems with depth perception and navigating front and back or up and down
Inability to recognize objects to the left side of a space
Inability to recognize the left side of one's own body (referred to by some as "alien hand syndrome")
Loss of proprioception (the ability to know where your body is oriented in your surroundings), causing misjudgment in movement and balance
Lack of awareness or concern about the left-sided impairment (hemispatial neglect)
Impulsive, manic, or inappropriate behaviors
With a left-sided parietal lobe stroke, there may be:
Paresthesia on the right side of the body
Inability to see out of the lower right quadrant of each eye
Difficulty with speech or language comprehension (aphasia)
Problems with simple mathematics
Impaired ability to read, write, and learn new information
Lack of awareness that a stroke had even occurred (anosognosia)
Cautious or hesitant behaviors
With bilateral (left and right side) parietal lobe strokes may result in:
Occipital lobe strokes are less common than strokes affecting the frontal lobes, temporal lobes, and parietal lobes. The occipital lobes are vital for visual processing. A stroke in the occipital lobe can potentially cause:
Vision loss or partial vision loss of one eye or both eyes. Damage to one side of the occipital lobe can cause homonomous loss of vision with exactly the same "field cut" in both eyes.
Brain insults in the parietal-temporal-occipital association area can cause word blindness with writing impairments (alexia and agraphia).
As with other sequelae of stroke, neuropsychological deficits improve over time and tend to recover over time. Rehabilitation efforts focus on restoring function or compensatory strategies. Neuropsychological evaluations provide needed information to identify cognitive and behavioral deficits, quantify severity, and work with rehabilitation team to develop rehabilitation programming. Also enables monitoring of restorative rehabilitation programming over time.