Robert,

It is my understanding that biomarkers precede clinical symptoms such as tremor. The goal is to establish a common set of markers to nab people early on before motor symptoms start. I think two of the more common predictors are anosmia or deficit in recognizing certains smells like pickles. Seriously, they use a scratch and sniff test. The other which holds a little more weight is REM Sleep Disorder; this is where people act out their dreams. If you experience both you are doomed:


Combination of 'idiopathic' REM sleep behaviour disorder and olfactory dysfunction as possible indicator for alpha-synucleinopathy demonstrated by dopamine transporter FP-CIT-SPECT

What I find alarming is that many of us will not have these markers. I, for one have an intact sniffer and do not have or never have had REM sleep disorder, so what does that say?

Further, I have read that the onset of PD is rapid and closely linked to a causative; this would be pre-motor phase. The progression of PD is not necessarily linked to cause. This strongly correlates to the flu pandemic of 1918. The flu can cause brain damage resulting in PD but the symptoms which are basically a sign of progression show years later. This happened with survivors of that flu...they awakened years later to PD motor symptoms. I guess I fail to see how biomarkers matter at this point when the damage is done early on; there are no symptoms, and any number of things possibly cause it. How do they know if biomarkers appear early enough to halt or reverse anything? I think it is a laudable goal but the cart is way before the horse, imho.

Laura