Spasticity, a disorder of muscle tone with its origin within the central nervous system, is usually a major component of cerebral palsy. It manifests as a velocity-dependent increase in tonic stretch reflex.
Patients with spasticity show increased resistance to passive limb motion.
Clinical characteristics of spasticity include the following:
- Crossed adductor reflexes
- Cocontraction of agonist and antagonist muscles is a major problem.
Symptoms of the upper motoneuron syndrome can be divided into positive and negative categories:
- Positive symptoms include spasticity and released flexor reflexes
- Negative symptoms include loss of finger dexterity, weakness and loss of selective control of muscles and limb segments.
Ref: Mayer NH. Clinicophysiologic concepts of spasticity and motor dysfunction in adults with an upper motoneuron lesion. Muscle Nerve 1997;20(suppl 6):S1-S13.