Muscle Spasticity: An Overview

Muscle spasticity is a common symptom of numerous neurological conditions that affect the central nervous system such as multiple sclerosis, cerebral palsy, spinal cord injury etc. It causes muscles to contract involuntarily or remain rigidly in flexed positions. This article provides an in-depth understanding of muscle spasticity including its causes, symptoms, impact and available treatment options.

What is Muscle Spasticity?

Muscle spasticity refers to an abnormal increase in muscle tone or increased resistance to passive movement of the muscles. It occurs when there is damage to the central nervous system. Normally the central nervous system maintains a balance between muscle contraction and relaxation through reciprocal innervation. However, in spasticity this balance is disrupted leading to continuous contraction of muscles. Severity of spasticity can range from mild muscle tightness to severe, uncontrollable spasms. Muscle Spasticity usually affects the lower limbs and presents as stiff, jerky movements. Spasticity hampers normal functioning and causes significant discomfort through chronic pain and contractures.

Causes of Muscle Spasticity

Neurological Conditions: Conditions that damage upper motor neurons like stroke, cerebral palsy, spinal cord injury, multiple sclerosis are a leading cause of spasticity. Damage to these neurons disturbs the normal inhibitory mechanisms that regulate muscle tone.

Injury or Damage: Traumatic brain or spinal cord injuries due to accidents or falls can also trigger muscle spasticity. Even minor injuries like whiplash can potentially cause spasticity if the damage affects motor pathways.

Genetic Disorders: Rare genetic disorders involving the central nervous system like amyotrophic lateral sclerosis can sometimes present with spasticity of the limbs.

Signs and Symptoms of Spasticity

The most common signs of spasticity include:

- Stiff, rigid muscles that are difficult to stretch out
- Jerky, involuntary movements of the affected limbs
- Exaggerated reflexes like legs jerking upwards when the sole is rubbed
- Constant muscle contractions causing painful cramping
- Hobbling or scissoring gait with crossover of legs while walking
- Constraint in active and passive movements of joints

For some, spasticity may only interfere with movements occasionally while others experience flares at all times with inability to control limbs. Severe cases can cause immobility, deformities and impair activities of daily living.

Impact of Spasticity

Muscle spasticity substantially diminishes quality of life through various means:

- Limited mobility and dependence on others for self-care activities
- Contractures - Shortening and tightening of muscles causes permanent joint deformities over time
- Chronic pain - Muscle spasms, cramps and pulled tendons lead to constant aching
- Sleep disturbances due to uncontrollable limb jerks during the night
- Social isolation, low self-esteem issues stemming from restricted activities
- Higher risk of skin breakdown from impaired mobility
- Economic burden of assistive devices, medications and therapies required to manage it.