Hello,

Is the doctor who saw the spasticity your neurologist? A movement disorder specialist? Both conditions cause an increase in tone. I've read this description many times, in many places:

"Rigidity is caused by an involuntary increase in muscle tone and it typically affects the muscles of the limb, prior to axial involvement. Initially, rigidity is unilateral, however, as the disease progresses, it becomes bilateral. Resistance is constant throughout flexion and extension and is not velocity dependent.

This is in contrast to the situation with spasticity, which is velocity dependent and has variable resistance through the range of motion (known as the clasp-knife phenomenon).

Rigidity may be described as cogwheeling, which is thought to reflect rigidity with superimposed tremor. Rigidity in the axial muscles results in the flexed posture that is characteristic of PD."

More here:

http://www.wemove.org/spa/spa_meas.html

The following study concludes that:

"Conclusions: Velocity dependence analysis indicates that rigidity and spasticity have approximately equal velocity dependent properties. For differentiating these two types of hypertonia, position dependent properties may be employed."

"spasticity showed progressively increasing muscle tension relative to position; rigidity showed increased (relative to the norm) but constant muscle tone over the entire stretch range"

Quantitative analysis of the velocity related pathophysiology of spasticity and rigidity in the elbow flexors
H-M Lee1, Y-Z Huang2, J-J J Chen3 and I-S Hwang

http://jnnp.bmjjournals.com/cgi/cont...tract/72/5/621

I can't answer your question about the existence of spasticity in IPD.

~Zucchini