Hypertonia

Hypertonia is a condition marked by an abnormal increase in the tightness of muscle tone and a reduced ability of a muscle to stretch (i.e. an increased stiffness). It is generally accompanied by (increased) spasticity of the particular muscles.

Spasticity is a disorder of the body's motor system 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.

Spasticity is usually caused by damage to the portion of the brain or spinal cord that controls voluntary movement. It may occur in association with spinal cord injury, multiple sclerosis, cerebral palsy (see Spastic Diplegia), 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 severe treatments maybe 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.

Treatment

If the cause is fatigue, the first remedy is rest. Massage seems to not be helpful. Stretching or relaxing the muscles involved may also work. Chronic spasms can lead to shortening of the muscles and ligaments. Regular (daily) exercises over the years ahead of these ligaments and muscles are needed to prevent the pain and the crippling of movement.

Treatment may include such medications as baclofen, diazepam, dantrolene, or clonazepam; muscle stretching, range of motion exercises, and other physiotherapy regimens to help prevent joint contractures (shrinkage or shortening of a muscle) and reduce the severity of symptoms; or surgery for tendon release or to block the connection between nerve and muscle, so that the muscle does not contract. The connection between nerve and muscle may also be blocked temporarily, without surgery, by injecting botulinum toxin into the muscle.

Prognosis

The prognosis for those with spasticity depends on the severity of the spasticity and the associated disorder(s). To a small degree spasticity performs the helpful role of exercise, but it is usually bothersome to normal activities in life.

Research

The NINDS supports research on brain and spinal cord disorders that can cause spasticity. The goals of this research are to increase scientific understanding about these disorders and to find ways to prevent, treat, and cure them.