Spasticity

Overview

Spasticity is a condition in which muscles are abnormally tight and stiff, and resist movement when stretched. It results from damage to the nerve pathways in the brain or spinal cord that normally control and balance muscle tone. When these signals are disrupted, the affected muscles receive too much excitatory input and not enough control, so they stay contracted and can spasm.

Spasticity is a symptom of an underlying neurological condition rather than a disease on its own. It commonly follows a stroke or brain injury and is a frequent feature of cerebral palsy, multiple sclerosis, and spinal cord injury. The severity ranges from mild tightness that is barely noticeable to severe stiffness that interferes with movement, positioning, comfort, and daily activities. With treatment, many people can reduce its impact and maintain better function.

Symptoms

Spasticity affects how muscles feel and move, and its impact depends on which muscles are involved and how severe it is.

• Muscle tightness and stiffness: Affected muscles feel hard and resist being stretched or moved.
• Increased muscle tone: A limb may feel rigid and difficult to bend or straighten.
• Spasms: Sudden, involuntary muscle contractions that can be uncomfortable or painful.
• Abnormal posture: Limbs may be held in fixed positions, such as a bent elbow or pointed foot.
• Reduced movement and coordination: Difficulty walking, reaching, or performing fine movements.
• Contractures: Over time, persistently tight muscles can shorten and limit joint movement permanently if not managed.

Spasticity can also cause pain, disrupt sleep, and make tasks like dressing or hygiene more difficult.

Causes

Spasticity arises when the control of muscle tone is disrupted by injury or disease affecting the brain or spinal cord.

• Stroke: Damage to brain regions controlling movement can leave muscles on one side tight.
• Cerebral palsy: A common cause in children, due to brain differences present from early life.
• Multiple sclerosis: Damage to nerve coverings disrupts movement signals.
• Spinal cord injury: Interrupts the pathways that regulate muscle tone below the level of injury.
• Brain or spinal cord injury and other conditions: Traumatic injury, lack of oxygen to the brain, and certain neurological diseases can all cause it.

Risk Factors

• Having had a stroke or traumatic brain injury
• A diagnosis of cerebral palsy
• Multiple sclerosis or other diseases affecting the central nervous system
• Spinal cord injury or disease
• Brain injury from lack of oxygen

Factors such as infection, pain, pressure sores, or a full bladder can temporarily worsen existing spasticity.

Diagnosis

Spasticity is diagnosed through clinical examination, with tests aimed at identifying the underlying cause.

• Physical and neurological examination: The clinician assesses muscle tone, reflexes, range of motion, and how movement is affected, often using rating scales to gauge severity.
• Review of medical history: To connect spasticity to a known neurological condition.
• Imaging: Brain or spinal cord scans (MRI or CT) to identify or confirm the underlying cause.
• Functional assessment: Evaluating how spasticity affects walking, daily tasks, and comfort to guide treatment.

Treatment

Treatment aims to reduce stiffness and spasms, prevent complications such as contractures, ease pain, and improve function. A combination of approaches usually works best.

• Physical and occupational therapy: Stretching, range-of-motion exercises, strengthening, and positioning form the foundation of care and help prevent permanent tightening.
• Oral medications: Muscle relaxants and other drugs that reduce muscle tone for more widespread spasticity.
• Botulinum toxin injections: Targeted injections to relax specific overactive muscles.
• Splints, braces, and casts: To maintain position and stretch tight muscles.
• Intrathecal baclofen: A pump that delivers a muscle-relaxing medicine directly around the spinal cord for severe spasticity.
• Surgery: In selected cases, procedures on muscles, tendons, or nerves can improve movement and comfort.

Treating triggers like infection, pain, or pressure sores can also lessen spasticity.

Prevention

Spasticity itself often cannot be prevented when its cause is established, but complications can be reduced and flare-ups limited.

• Keep up regular stretching and prescribed exercises to maintain range of motion
• Use splints, braces, or positioning as recommended
• Treat infections, constipation, and pressure sores promptly, since they can worsen spasticity
• Manage pain, which can increase muscle tightness
• Reduce stroke and injury risk through general healthy habits and safety measures

When to See a Doctor

See a doctor if muscle stiffness or spasms interfere with movement, comfort, sleep, or daily activities, or if spasticity is getting worse. Also seek care if you notice:

• New or rapidly worsening stiffness, which may signal an infection or another problem
• Joints that are becoming fixed or hard to move
• Skin breakdown or pressure sores in areas held in one position

If spasticity follows a sudden event with weakness, slurred speech, or facial drooping, seek emergency care, as this may indicate a stroke.

Related Topics

Frequently Asked Questions

References

1. National Institute of Neurological Disorders and Stroke (NINDS). Spasticity.
2. MedlinePlus, U.S. National Library of Medicine. Muscle spasticity.
3. American Association of Neurological Surgeons (AANS).
4. Mayo Clinic. Spasticity.