Spasticity is a state of excessive muscle tone manifested by increased resistance to passive stretching and exaggerated reflexes. It is most often detected during rapid passive movement of a muscle, which shows heightened resistance. Spasticity is typically caused by upper motor neuron lesions and most commonly affects the arm and leg muscles. Chronic spasticity may lead to muscle fibrosis, contractures, and functional limitations.

History and physical examination

When assessing spasticity, obtain a detailed history that includes the onset, duration, and progression of increased muscle tone. Ask about events that may precipitate or worsen the spasticity, and inquire about associated muscular changes, such as weakness, spasms, or functional limitations. Review the patient’s history for trauma, degenerative disease, vascular insults, or neurologic disorders.

Conduct a full neurologic examination, including:

• Muscle tone evaluation (resistance to passive movement)

• Deep tendon reflexes (DTRs)

• Assessment for clonus

• Evaluation of muscle wasting and contractures

• Sensory and motor function in all limbs

Take vital signs and document any signs of autonomic dysfunction, especially in patients with spinal cord involvement.

Pathophysiology

Spasticity arises from disruption of the pyramidal and extrapyramidal tracts that modulate muscle tone. Motor fibers from the motor cortex, basal ganglia, brainstem, and spinal cord converge at the anterior horn of the spinal cord, regulating muscle stretch via the stretch reflex arc. Normally, muscle stretch triggers reflexive contraction, which is modulated by inhibitory signals to maintain muscle length and tone.

Damage to descending inhibitory tracts removes this modulation, producing uninhibited muscle stretch, exaggerated reflex activity, and uncontrolled contraction. Over time, persistent hypertonicity leads to fibrosis and contracture formation.

Emergency interventions

• If spasticity is associated with recent trauma or tetanus, monitor airway and respiratory function closely.

• Provide ventilatory support if respiratory muscles are involved.

• Administer pain relief and antispasmodic medications as indicated.

• In cases of severe, uncontrolled spasticity, nerve blocks or surgical intervention may be necessary for permanent relief.

• Maintain a calm environment to reduce reflex-triggered spasms.

Medical causes

Special considerations

• Prepare the patient for diagnostic studies, including electromyography (EMG), muscle biopsy, MRI, or CT of brain and spinal cord.

• Implement passive range-of-motion exercises, splinting, traction, and heat therapy to prevent contractures and reduce spasms.

• Provide pain control and antispasmodics.

• Maintain bed rest as needed in acute episodes.

• In chronic, severe spasticity, consult neurology or surgical teams for interventions such as nerve blocks or surgical transection.

Patient counseling

• Teach safe use of assistive devices to maintain independence.

• Educate the patient and caregivers on spasm prevention techniques, proper exercise regimens, and skin protection.

• Discuss the importance of follow-up with physical therapy and neurology specialists.

Pediatric pointers

• In children, spasticity may indicate cerebral palsy, especially if observed in early motor milestones.

• Evaluate for coexisting developmental delays, contractures, and functional limitations.

• Early physical therapy and orthopedic interventions are critical for long-term function.

References

1. Brainin, M., Norrving, B., Sunnerhagen, K. S., Goldstein, L. B., Cramer, S. C., Donnan, G. A., … Graham, G. (2011). Post stroke chronic disease management: Towards improved identification and interventions for post stroke spasticity-related complications. International Journal of Stroke, 6(1), 42–46.

2. Yelnik, A. P., Simon, O., Parratte, B., & Gracies, J. M. (2010). How to clinically assess and treat muscle overactivity in spastic paresis. Journal of Rehabilitative Medicine, 42(9), 801–807.