What is Spasticity?

Spasticity is not a disease in itself but a term used to describe one or more symptoms which can result from malfunctioning of the nervous system, brain or spinal cord.

Spasticity is caused by damage to the portion of the brain that serves the nerve pathways regulating muscles and controlling voluntary movement.

How normal movement occurs

Despite it seeming simple, normal muscle control is actually very complex, involving several regions of the brain and spinal cord. Voluntary movement of a muscle begins when electrical signals are generated in the brain. These electrical signals pass to the spinal cord. The spinal cord then sends signals out to the surface of the muscle involved.

To control physical movement we need to be able to tighten and relax the muscles controlling our joints. All joints are controlled by two opposing sets of muscles one that bends (or flexes) the joint, and another which straightens (or extends) it.

Spastic muscles are resistant to the normal stretching that occurs during use, and may remain abnormally contracted for long periods. This contraction causes stiffness or tightness of the muscles and may interfere with walking, movement, and speech.

Even when we are inactive or relaxed the body maintains muscle tone. To see this, lay your hand, palm up, on a table and let it relax. Its 'natural' position is slightly curled up - this is the result of normal muscle tone. Too little tone and limbs become floppy. But with spasticity there is too much tone. The result being fingers may become curled up or tightened. This increased tone occurs in other areas of the body too.

When this increased muscle tone is left unchecked it can develop into contractures where the muscles become so tightened they can't be straightened out. This can make normal mobility impossible and can also cause painful muscular spasms.

Contractures

A contracture is an abnormal joint posture due to persistent muscle shortening. Contracture is one of the most noticeable consequences of spasticity. Once this happens it sets off a vicious cycle. When a muscle is not regularly put through its full range of motion, its tendons shorten. This makes stretching the muscle even more difficult, so even more shortening and decreased stretch occur. The muscle may also develop scar tissue, further impeding full range of movement. The outcome of untreated contracture is a fixed, often painful, abnormal posture.

Why does Spasticity occur?

Spasticity is a very common complication of a number of neurological conditions including cerebral palsy, brain injuries, spinal cord injuries, multiple sclerosis (MS) and stroke:

Cerebral Palsy

Cerebral Palsy (CP) is a physical impairment that affects movement. It develops as a result of a failure of part of the brain to develop either in the unborn baby or during early childhood. It can take various forms but all are characterised by movement impairment.

Multiple Sclerosis (MS)

Multiple Sclerosis is the most common neurological disorder among young adults. Its causes are unclear, although environmental, genetic and family connections may play a role. The result is damage to a substance called myelin. Myelin is a protective sheath surrounding all the nerve fibres in the brain and spinal cord and damage to this sets off problems in the central nervous system. MS affects around 85,000 people in the UK and three quarters of those with MS experience some form of spasticity.

Head Injuries

Head injuries occur from a variety of causes often through road traffic or other kinds of accidents. Around 10,000 people annually sustain severe brain damage and 30% of these are likely to require treatment for the spasticity that occurs.

Stroke

Strokes occur when there is an interruption of blood supply to a localised area of the brain. When the brain is deprived of blood brain cells die or become damaged. There are around 300,000 people in the UK living with disabilities following a stroke and 20% of these will be affected by spasticity.

What are the symptoms of spasticity?

Where spasticity is present an increase of muscle tone can result in stiff limbs, restricted movement and difficulty in undertaking normal activities such as walking, eating and self care. Spasticity is also often complicated by sudden violent muscle contractions (spasms) which can be very painful.

The symptoms of spasticity can range from slight muscle stiffness to deformity, permanent muscle shortening and contracture. When spasticity pulls joints into abnormal positions or prevents normal range of movement it can be very painful as well as causing other complications eg pressure sores. While spasticity can affect any muscle group, definite clinical patterns occur, creating well-recognised limb deformities.

People with spasticity usually report a feeling of tightness or stiffness in their legs or arms. Occasionally, the legs will cramp up and go into spasm, which can disrupt sleep. Spasticity often makes walking difficult, patients are often stiff-legged and walking requires great effort and there is a general loss of grace and agility about their walk.

Symptoms include:

• Stiffness making actions less precise, particularly delicate movements eg of the hands and fingers to perform certain tasks difficult.
• Muscle spasms - uncontrollable muscle contractions causing pain
• Scissoring (involuntary crossing of the legs),
• Deformities from fixed joints
• Fatigue caused by trying to force the limbs to do something they want to resist.

Other complications include:

• Urinary tract infections
• Chronic constipation
• Fever or other systemic illnesses
• Pressure sores
  

What are the effects of spasticity?

Daily living:

The inability to control muscles independently can bring about difficulty in doing all kinds of every day activities from dressing, to writing, eating, and grooming. This often means relying on others to assist with these activities and a loss of independent living.

Hygiene:

Stiff limbs and contractured muscles can prevent access to such areas as the palm, armpit, or groin, interfering with cleaning and skin breakdown may occur. Spasticity can also make it difficult to deal with urinary or bowel problems including inserting catheters or giving enemas.

Comfort:

Spasticity can cause discomfort in sleeping and sitting. The inability to change positions to ease these activities can result in further pain, stiffness or pressure sores.

Emotional Distress:

Feelings of frustration and helplessness are common as every day tasks become difficult to manage and when there is an increasing need to rely on others for help. Lack of mobility can bring isolation also many people feeling conscious of the physical appearance of their spasticity and want to avoid unnecessary contact with friends, family and wider society. There may also be feelings of guilt about disrupting the lives of those closest who have to care for you.

Treatments

Treatment may include medication, injections, stretching exercises, and other physical therapy regimens to help prevent stiffness and joint contractures and reduce the severity of associated symptoms. Surgery for tendon release or for cutting the nerve-muscle pathway may be considered in some cases.

Frequently a combination of anti-spasticity treatments is far more effective than any single one. Treatment is most effect when the physician other therapists, patient and carers approach the problem together working towards a common goal.

In some cases, no treatment is necessary or desirable. Evaluation by a medical professional is crucial to determine the best course of treatment.

For further information on treatments see Managing Spasticity