SPASTICITY

Spasticity is a disorder of the body motor system,and especially the central nervous system (CNS), in which certain muscles are continuously contracted. This contraction causes stiffness or tightness of the muscles and may interfere with gait, movement, and speech. The person with the spastic muscles may or may not feel it, know about it or want to do something about it. The human motor system is not always linked with the sensory systems, nor the voluntary-muscle systems.

Voluntary movement is controlled by several interacting systems within the nervous system. Primary control is through the upper motor neurons in the motor cortex of the brain, which send their axons via the cortico-spinal tract to connect to lower motor neurons in the spinal cord. Spasticity is caused by damage to upper motor neurons or to the cortico-spinal tract. It may occur in association with spinal cord injury, multiple sclerosis, cerebral palsy, anoxic brain damage, brain trauma, severe head injury, some metabolic diseases such as adrenoleukodystrophy, and phenylketonuria.

Symptoms may include hypertonia (increased muscle tone), clonus (a series of rapid muscle contractions), exaggerated deep tendon reflexes, muscle spasms, scissoring (involuntary crossing of the legs), and fixed joints. The degree of spasticity varies from mild muscle stiffness to severe, painful, and uncontrollable muscle spasms.

The condition can interfere with rehabilitation in patients with certain disorders, and often interferes with daily activities. Over the years, it may increase in its effect, so more treatments may be needed later. Cold weather and fatigue can trigger spasms more severely than other times. Multi-tasking (such as walking, talking, eating and other activities) can also trigger more severe spasticity.