Spastic weakness of the muscles innervated by the cranial nerves, i.e., the muscle of the face, pharynx, and tongue, due to bilateral lesions of the corticospinal tract.

Progressive supranuclear palsy (PSP) is a late-onset neurodegenerative disease involving the gradual deterioration and death of specific volumes of the brain. The condition leads to symptoms including loss of balance, slowing of movement, difficulty moving the eyes, and cognitive impairment...