From the Guidelines
Spasticity is defined as velocity-dependent hyperactivity of tonic stretch reflexes, resulting in significant pain and functional disturbances, particularly contractures and skin hygiene issues. This condition is characterized by abnormal muscle tone and increased muscle stiffness or tightness that interferes with normal movement, speech, or posture, typically affecting the antigravity muscles 1. The underlying mechanism involves hyperexcitability of the stretch reflex due to reduced inhibitory signals from the brain, causing muscles to contract more readily in response to stretching. Some key points to consider about spasticity include:
- It is one of the most important impairments for patients after stroke, and can result in significant pain and functional disturbances 1
- The most impairing state from spasticity may be contractures, rendering the affected limb functionless, and skin hygiene may also be a problem 1
- Treatment options typically involve a stepwise approach, beginning with the least-invasive modalities and progressing to more invasive, including positioning, passive stretching, and range of motion exercise, as well as oral medications like tizanidine, baclofen, dantrolene, and diazepam 1. The most effective treatment approach should prioritize the least-invasive modalities, such as positioning, passive stretching, and range of motion exercise, to provide relief and prevent contractures, with oral medications used as needed to manage symptoms.
From the Research
Definition of Spasticity
- Spasticity is a component of the upper motor neuron (UMN) syndrome, resulting from various neurologic conditions such as stroke, brain injury, spinal cord injury, multiple sclerosis, and cerebral palsy 2, 3, 4, 5, 6.
- It is characterized by a velocity-dependent increase in resistance, i.e., hypertonia, and can manifest as involuntary muscle hyperactivity, rigidity, dystonia, and spasms 3, 4.
- Spasticity can be described as a phenomenon of uncontrolled, repetitive, involuntary contractions of skeletal muscles, leading to significant pain and limited mobility 3.
Clinical Presentation
- Spasticity presents as upper motor neuron symptoms, including increased tone, clonus, spasms, spastic dystonia, and co-contractions 5.
- The impact of spasticity can vary from a subtle neurological sign to severe spasticity causing pain and contractures 5.
- External factors such as constipation, urinary tract infections, or pressure ulcers can worsen existing spasticity 5.
Forms of Muscle Hyperactivity
- Spasticity sensu strictu: involuntary muscle hyperactivity triggered by rapid passive joint movements 4.
- Rigidity: involuntary muscle hyperactivity triggered by slow passive joint movements 4.
- Dystonia: spontaneous involuntary muscle hyperactivity 4.
- Spasms: complex involuntary movements usually triggered by sensory or acoustic stimuli 4.