Problem is you can have mixed tremors (not a formal term, just my way of calling it).

I have a slight resting tremor on my right hand since I was diagnosed a couple of years ago (the SPECT is quite clear in this, I could clearly tell something was wrong on my brain's left side). This tremor is always there.

But I always tell my neurologist that my worse secondary PD symptom is anxiety. I have clearly noticed higher anxiety doing my job (which is not a life or death job, just business management); and even though I realize that my response is disproportionate I can't avoid it. In those situations I have tremor in both of my hands. This tremor is reduced if I take propanolol.

I think (another hypothesis, I'm not a doctor) that the dopamine / glutamate unbalance in PD may be a cause for anxiety.