Are there early symptoms in Parkinson's Disease?

As in so many medical situations, the answer is yes... and no. The "cardinal triad" of PD: Bradykinesia (slow movements), rigidity (stiffness) and tremor (shaking), usually show up in a different order for different patients and usually start out on one side. By the time the patient has has all the symptoms on both sides, the diagnosis of a parkinsonian syndrome is obvious. commonly, though, it will begin with some shaking in one hand and progress from there. At that stage, there can be quite a bit of uncertainty as to what it represents. When the initial symptom is as vauge as some assymetrical stiffness, you can see how hard it is to be sure early on.

There is no definitive laboratory test to confirm the diagnosis. There are definitive pathological changes in the brain that can confirm the diagnosis, but very few would advocate brain biopsy to determine this earlier in the disease course. There are no proven preventative therapies or "neuroprotective" therapies that would slow the progression of the disease, so treatment centers on symptom reduction. For these reasons, early diagnosis isn't terribly helpful at this point.

Extensive research continues to search for neuroprotective treatments and the early diagnosis tests to make such a strategy effective.