PSP or Steele–Richardson–Olszewski disease (SROD) is an idiopathic, sporadic disease, with onset in middle or late life. It is characterized clinically by a supranuclear gaze palsy, especially for vertical gaze and particularly downgaze, neck rigidity, and dystonia, a predominantly axial akinetic–rigid parkinsonian syndrome, a pseudobulbar palsy, loss of equilibrium with frequent falls, and a frontal lobe-type dementia. The condition is progressive and leads to death on average about 6 years from the onset.

Neuropathologically, the condition is characterized by widespread neuronal loss, glial...

PSP or Steele–Richardson–Olszewski disease (SROD) is an idiopathic, sporadic disease, with onset in middle or late life. It is characterized clinically by a supranuclear gaze palsy, especially for vertical gaze and particularly downgaze, neck rigidity, and dystonia, a predominantly axial akinetic–rigid parkinsonian syndrome, a pseudobulbar palsy, loss of equilibrium with frequent falls, and a frontal lobe-type dementia. The condition is progressive and leads to death on average about 6 years from the onset.

Neuropathologically, the condition is characterized by widespread neuronal loss, glial changes, and the presence of characteristic NFT, mainly in diencephalic and brainstem nuclei and tau-positive filamentous inclusions in both neurons and glia.