This is the description of progressive supranuclear palsy (PSP) written by Parkinson’s Australia in 2002.
Finally I’ve found a definition of pseudobulbar palsy:
“pseudobulbar palsy [nerve problems that affect the muscles of the palate, tongue and throat, causing problems with swallowing, gagging and speech]”

This August 8, 2000 document on the phases/stages of progressive supranuclear palsy (PSP) was written by two caregivers who were members of the now-defunct Johns Hopkins PSP Listserv. Many neurological diseases, such as Alzheimer’s and Parkinson’s, have “stages.” So this was an attempt by two PSP caregivers to have the same guide posts for the PSP community.