Motor and Functional Impairments after Stroke

Stroke, depending on its severity, can result in certain motor impairments, which ultimately lead to a few functional challenges. At times, these limitations (caused by neurological deficits) are enhanced by physical deconditioning due to inactivity. The specificity of such impairments varies with the degree of brain damage and the region(s) of the central nervous system (CNS) that have sustained damage.

Approximately 50% of stroke survivors are left with disabilities due to motor impairments, which make them dependent on others for activities of daily living (ADL). Because motor impairments limit an individual’s capacity to execute ADL and walk safely, the stroke victim suffers certain functional impairments. These impairments are commonly complemented with weakness on one side of the body, problems with vision and emotional challenges (fear, anxiety, sadness, frustration and grief). Additionally, due to Apraxia, the stroke survivor faces difficulty with the motor planning to perform tasks or movements when asked, even if the command is understood and the patient is willing to perform the task.

While a number of motor training 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 relearning the forgotten motor function. Common motor and functional impairments after stroke include:

Paralysis

Paralysis is among the most shared functional disability resulting from stroke as 9 out of 10 survivors experience some degree of paralysis right after a stroke. Paralysis refers to a muscle or a muscle group’s inability to move voluntarily. Muscles are controlled by messages sent from the brain. When a part of the brain is damaged following a stroke, messaging between the brain and muscles do not work properly. Paralysis, which is observed on the opposite side of the damaged brain, may affect any part of the body.

Hand motor impairment

Hand motor impairment is observed due to a deficit in motor execution and a deficit in higher-order processes (motor planning and motor learning), which lead to impaired one-handed motor control in stroke victims. Deficits in hand motor control can be detected by examining movements during natural movements and the coordination of fingertip forces.

Upper limb dysfunction

Upper limb dysfunction remains the most common reason behind functional Impairment(s) after a stroke. Research indicates that only 5% of adult stroke victims regain fully functional upper limb through rehabilitation while 20% regain none.

Understanding post-stroke upper limb impairment is essential to restore its function. However, functional rehabilitation of upper limb can be a bit challenging as Upper limb dysfunction is not static. As motor recovery proceeds, the type and nature of the impairments may change.