spasticity
A velocity-dependent increase in muscle tone with exaggerated tendon reflexes, resulting from upper motor neuron lesions.
Full Definition
Spasticity is characterized by increased resistance to passive movement that varies with the speed of stretch, often accompanied by clonus and hyperreflexia. It results from damage to descending motor pathways in the brain or spinal cord, leading to disinhibition of spinal reflexes. The condition typically follows a predictable pattern affecting antigravity muscles and can significantly impair function and cause pain. Management involves medications, physical therapy, and sometimes surgical interventions like intrathecal baclofen pumps.
Usage
Usage note: Distinguish from rigidity, which lacks velocity dependence and occurs in extrapyramidal disorders.
In Context
- "The patient developed progressive spasticity following spinal cord injury." — Clinical progress note
- "Botulinum toxin injections reduced focal spasticity in the affected limbs." — Treatment documentation