What is the difference between progressive supranuclear palsy (psp) and parkinson's disease?

Overlap: Both are degenerative brain disorder. In psp there are eye movement disorder along with some parkinonian features. Also course of the disease is different.

Difft diseases: Psp usually limited to eye movement. Pd affects extremities.

Parkinson's Disease: Progressive supracuclear palsy is a severe form of parkinsonism. It is characterized by no or minimal response to levodopa, prominent subcortical cognitive impairment, severe balance disorder, axial dystonias, and the classical inability to voluntarily move eyes in vertical plane. In contrast, idiopathic parkinson's disease commonly has better response to levodopa, resting tremors, slower decline.