Chapter 31 - Progressive Supranuclear Palsy

Summary

PSP was identified in 1963 by Richardson, Steele and Olszewski, as an “unusual syndrome” characterized by axial rigidity, bradykinesia, postural instability with falls, cognitive deficits, and supranuclear vertical gaze palsy, with uniform tau pathology predominating in the neurons of the pallido-nigro-luysian axis. The classical view is that tau protein and neuropil thread accumulation appears mainly in the subthalamic nucleus, red nucleus, substantia nigra, pontine tegmentum, striatum, oculomotor nucleus, medulla, and dentate nucleus, but there is growing evidence that cortical tau pathology is also common. Tau pathology uniformly predominates in the neurons of the pallido-nigro-luysian axis, but clinical PSP subtypes confirmed differential distribution patterns of neuronal, astroglial, and oligodendroglial tau pathologies both in total tau load and cell-type specific vulnerability patterns of brain regions, suggesting distinct dynamics or circuit-specific segregation of propagation of tau pathologies with accumulation of brainstem neurofibrillary tangles. Here, the novel clinicopathologic classification of PSP syndromes with specifically underlying neuropathology is discussed.