What is the cause of spasticity in paralysis?

Different theories. There are many different theories about what causes spasticity but the best explanation that i can give you is that under normal circumstances there is a balance between excitation and inhibition of muscle tone and movement. When there is injury or disease of the central nervous system (brain and spinal cord), there is excess excitation and not enough inhibition and the tone of certain muscles.

Related Questions

What can cause spastic paralysis on the right side of the body?

Anatomy. Causes include focal lesions of brain and spinal cord, and some underlying problems could include trauma, stroke, multiple sclerosis, infections, even primary lateral sclerosis. Read more...

What could cause spastic paralysis on the right side of the body?

Central lesion. Brain injury from trauma, bleed, tumor, aneurism, ischemia, infection, or spinal cord injury from similar mechanisms all can cause an upper motor lesion resulting in both paralysis and spasticity simultaneously. Read more...