Hypertonicity vs spasticity
Clinical evaluation and management of spasticity, Jeffery et. al.2002
1-hypertonicity or spastic dystonia is a continues increase in the muscle tension without regarding to the movement and is dependent upon afferent information from feedback following movements of stretch , decorticat and decerbrate rigidity are a form of spastic dystonia, spastic dystonia is considered to be a form of sustained efferent muscular hyperactivity , dependent on continues supraspinal derive to the alpha motor neuron[1]
The- spasticity is a velocity dependent increase in muscle tone in regarding to passive movement,
-neural component of spasticity: pyramidal tract lesion , pyramidal tract injury doesn't give raise to spasticity[2] (BURKE),
the main symptoms are weakness and loss of dexterity which is greater in distal than in the proximal muscles,
- pyramidal tract is the system which balance the muscle tone.-the key tracts are :
1-DRT : Has inhibitory effect on MRT &VST
2-MRT & 3- VST : they have facilitatory effect on the extensor tone,
- all the three systems are though to inhibit flexor reflex afferents responsible for flexor spasm[3](BROWN 1994)
