The current Lancet is a PD special.
Register - a quick and simple process - and you get free access to three papers:
Epidemiology of PD.
Pathogenesis.
Treatments.
I suppose it represents the current state of (conventional) knowledge. ..certainly for the UK.
Perhaps nothing revelatory but worthwhile...and, in terms of medication choice, provides an insight into the approach your neuro - if they're up to speed - is likely to take.
So you know the cause of PD or at least what should be the cause or the cure or at least the treatment. 
Low Magnesium and PD
PD drugs accelerate disease progression 
PD Irreversible?
PD: the gut, covid, etc.
