Spasticity Health Article

Definition

Spasticity is an abnormal increase in muscle tone. It may be associated with involuntary muscle spasms, sustained muscle contractions (dystonia), and exaggerated deep tendon reflexes that make movement difficult or uncontrollable. Although it most commonly affects the legs and arms, spasticity can affect any part of the body including the trunk, neck, eyelids, face, or vocal cords.

Description

Spastic muscles are resistant to the normal stretching that occurs during use and may remain contracted for long periods. Spasticity may not be present all the time and varies based on initial muscle tone; length of responding muscle groups; and the person's position, posture, and state of relaxation. Spasticity may increase with anxiety, emotions, pain, or sensory stimulation. It may worsen with movement of the involved muscles. Spasticity may be aggravated by temperature extremes, humidity, skin problems such as a pressure ulcer or ingrown toenail, bladder or bowel problems, infections, and sometimes tight clothing.

The severity of spasticity ranges from slight muscle stiffness to spasms that come and go, to permanent contracture. Spasticity-induced contracture can be treated with medications. If muscle contractures are not treated, fixed contracture can occur, leaving the muscle permanently shortened.

Severe spasticity can interfere with a child's normal functioning, motor and speech development, and/or comfort. Spasticity can be painful, especially if joints are pulled into abnormal positions or if range of motion is limited.

Simple activities of daily living (such as walking, eating, dressing, and bathing) may become time-consuming and difficult for both the child and caregiver. When spasticity limits activity for long periods, it can cause additional medical problems such as sleep disturbances, pressure sores, and pneumonia.

Demographics

The exact incidence of spasticity is not known. Estimates report spasticity may affect over 500,000 Americans and over 12 million people world-wide.

Causes

Spasticity occurs when certain nerve signals do not reach the muscles because of injury or disease that affects parts of the brain or spinal cord. With spasticity, muscles receive improper nerve signals, causing them to contract, while the brain is unable to communicate with the motor nerves to stop the muscles from contracting.

Common neurological conditions associated with spasticity include cerebral palsy, brain injury or trauma, severe head injury, stroke, multiple sclerosis, spinal cord injury, and some metabolic diseases.

Symptoms

Spasticity is characterized by increased muscle tone (hypertonicity) and by muscle stiffness.

Symptoms associated with spasticity include the following:

• increased muscle stretch reflexes
• involuntary contraction and relaxation of muscles (spasms)
• prolonged muscle contractions (dystonia)
• rapid, repetitive jerky motions (clonus)
• exaggerated deep tendon jerks or reflexes
• involuntary crossing of the legs (also called scissoring reflex)
• abnormal posture or abnormal positioning of the shoulder, arm, wrist, or finger
• increased resistance to movement of certain muscle groups

When to call the doctor

If a child has any of the following symptoms, the parent or caregiver should call the child's doctor:

• worsening spasticity
• apparent development of muscle contractures
• worsening overall health

Diagnosis

A diagnosis of spasticity is often made with the diagnosis of cerebral palsy or following a brain or spinal cord injury. A multi-disciplinary team may be consulted to provide an accurate diagnosis of spasticity so the proper treatment can be planned.

The diagnosis of spasticity includes:

• review of personal and family medical history
• review of current medications
• review of other health problems
• physical examination
• diagnostic tests

The medical history helps the physician evaluate the presence of other conditions or disorders that might contribute to or cause the spasticity. Records of previous diagnoses, surgeries, and treatments are reviewed. The child's family medical history is evaluated to determine if there is a history of muscular or neurological disorders.

Questions about the child's medical history may include:

• When were the symptoms first noticed?
• How long have the symptoms lasted?
• Are the symptoms always present?
• What muscles are affected?
• What makes the symptoms improve?
• What specific treatments or techniques have been tried?
• What makes the symptoms worse?
• Do certain activities, emotions, or events seem to aggravate the symptoms?
• Are other symptoms present?
• Is the spasticity preventing function or independence?

The doctor will review the presence of other health problems such as swallowing function, bowel and bladder function, and learning difficulties.

The physical exam may include an evaluation of the child's motor reflexes including muscle tone, mobility, strength, balance and endurance; heart and lung function; cranial nerve function; and an examination of the child's abdomen, spine, throat, and ears. The child's height and weight and blood pressure also are checked and recorded.

To confirm the diagnosis of spasticity, the following tests can be performed to evaluate the child's arm and leg movements, muscular activity, range of motion, and ability to perform self-care activities:

• x rays of the spine and hips
• occupational and physical therapy evaluations to determine upper and lower extremity movement patterns and passive range of motion
• diagnostic blocks with local anesthetics to provide information on the effectiveness of potential treatments
• nerve conduction studies to evaluate muscle or nerve damage
• electromyogram (EMG or myogram) to detect abnormal muscle electrical activity.

Nerve conduction studies and an electromyogram (EMG) are usually performed together to provide a comprehensive assessment of nerve and muscle function. In both tests, the examiner uses a computer, monitor, amplifier, loudspeaker, stimulator and high-tech filters to see and hear how the muscles and nerves are responding during the test.

In the nerve conduction study, small electrodes are placed on the skin over the muscles to be examined. A stimulator delivers a very small electrical current (that does not cause damage to the body) through the electrodes, causing the nerves to fire. In the electromyogram, a very thin, sterilized needle is inserted into various muscles, usually those affected most by spasticity symptoms. The needle is attached by wires to a recording machine. The patient is asked to relax and contract the muscles being examined. The electrical signals produced by the nerves and muscles during these tests are measured and recorded by a computer and displayed as electrical waves on the monitor. The test results are interpreted by a specially trained physician.