Deidre,
I had never heard of PCP. Had to Google it. We have a friend with cerebellar atrophy, and it sounds similar. A devastating dx, and my heart goes out to you! Do you have a prognosis associated with that?
There are treatments that might halt the PCa progression that seem to have minimal side effects, like zytiga.
With such a big rise, the only way to know what's going on is to get scans. Even then, no telling how long he would survive if nothing was done, but treating often reduces the pain, etc associated with the cancer.
So really sorry that your guy got hit so hard twice. It must be so hard for you. I hope will keep us updated on how you're both doing.
Beth

PSP:
Progressive supranuclear palsy, also called Steele-Richardson-Olszewski syndrome, is an uncommon brain disorder that causes serious problems with walking, balance and eye movements. The disorder results from deterioration of cells in areas of your brain that control body movement and thinking.

Progressive supranuclear palsy worsens over time and can lead to life-threatening complications, such as pneumonia and swallowing problems. There's no cure for progressive supranuclear palsy, so treatment focuses on managing the signs and symptoms.