Stroke, depending on its severity, can result in certain motor, cognitive and sensory impairments. While motor deficits after stroke are typically more obvious, cognitive and sensory problems are identified during the course of the rehabilitation process. The link among post-stroke impairments has not specifically been a subject of interest in stroke research until now.
These impairments are also commonly observed with weakness in one side of the body, problems with vision and emotional problems (fear, anxiety, anger, sadness, frustration, and grief). The stroke survivor’s ability to eliminate any of these impairments depends on which side and part of the brain was affected. The degree of brain damage and the survivor’s general health before the stroke also hold great importance.
Due to Apraxia, a common motor disorder caused by stroke, the patient face difficulty with the motor planning to perform tasks or movements when asked, even if the command is understood and the stroke survivor is willing to perform the task. The nature of the brain damage after stroke determines the severity of this condition.
Hand motor impairments after stroke are observed with a deficit in motor execution and higher-order processes (motor planning and motor learning), which lead to impaired dexterity in stroke survivors. Deficits in hand motor control following a stroke can be detected by examining the coordination of fingertip forces and movements during natural movements.
While a number of motor learning therapy protocols are being used to rehabilitate motor control, little is known about the types of motor learning impairment that occur after stroke and what role the location of damage (within the brain) plays in motor relearning.
Nearly half of the stroke survivors are left dependent on others for activities of daily living (ADL). Upper limb dysfunction remains the most common reason behind functional Impairment(s) for many stroke survivors. The functional ambulation limits the stroke survivor’s capacity to execute safe, efficient walking within environmental constraints encountered in everyday life. Paralysis, a loss of muscle function for one or more muscle (caused by damage to the nervous system) can further affect an individual’s functional life after stroke.
The specificity of functional impairment(s) after stroke varies with the region(s) of the central nervous system (CNS) that have sustained damage.
Cognitive deficits after stroke include difficulty in solving problems and planning a day, as well as different kinds of memory problems and communication challenges. Stroke survivors often face difficulty in:
Serval studies reveal that people with left-brain stroke tend to experience more short-term memory problems. Patient with right-brain stroke tend to confuse information or misinterpret and as a consequence, mix up the event details.
In addition to Aphasia, post-stroke communication deficits may include decreased attention, distractibility, the inability to understand the emotional context of a message and the inability to understand body language. Some survivors are even unable to ‘read’ and refrain from certain behaviors such as not getting off a specific topic during conversation. Sometimes, problem-solving ability and decision making are also affected in survivors of right-brain strokes.
An individual’s sensation can also be affected after stroke. While not every stroke survivor will have problems with sensation, some may lack precision and control without having to known sensation. Common sensory impairments post stroke include the loss or reduced touch, the loss or reduced temperature sensation, hypersensitivity to sensation, the loss of sensation from the bladder or bowel, Paresthesia (Altered sensation) and Proprioception (the sense of the relative position of one’s own parts of the body).
Post-stroke vision problems can fall into two categories – vision loss (or vision field loss) and vision perception problems. An individual’s vision depends on eyes to receive information and the brain to process that information. The nerves from each eye are connected to the occipital cortex at the back of the brain, allowing an individual to see. Since most strokes affect one side of the brain, the left side vision in each eye may be affected if the right side of your brain is damaged. Visual field loss after stroke may include Homonymous Hemianopia (visual field loss on the left or right side of the vertical midline) and Quadrantanopia (blindness in a quarter of the visual field).
Stroke-led damage to brainstem makes it difficult to process what the eye sees, resulting in vision perception problems. One may find it difficult to coordinate movement and focus eyes resulting in double vision. Visual neglect (also called inattention) and Agnosia (inability to interpret sensations and hence to recognize things as a result of brain damage after stroke) can often be complemented with double vision.