This is Tomba again. I've been doing more study on this subject so I'll share, but please remember I am no doctor nor laydoctor or anything medical except a cadaver to study later, so always follow your docs advice, not mine.
Not only do the lung muscles weaken due to PD itself & cause these kinds of symptoms, but the dyskinesia from the meds cause them too. Yes, synemett works, but also backfires. Times up. Look under PD & respitory system. There are lung excersizes, etc. 20 per cent deaths in PD caused by pnumonia in PD due to these complications