A 70-year-old man presents with a 2-year history of progressive dementia, rigidity, and falls. Autopsy shows neuronal loss in the substantia nigra and basal ganglia with pale-staining neuronal cytoplasmic inclusions that are tau-positive. This is most consistent with:

• A Parkinson disease (alpha-synuclein Lewy bodies)
• B Progressive supranuclear palsy (PSP) with tau-positive globose neurofibrillary tangles and tuft-shaped astrocytes ✓
• C Alzheimer disease with neurofibrillary tangles predominantly in the hippocampus
• D Corticobasal degeneration with astrocytic plaques and ballooned neurons

Explanation

Progressive supranuclear palsy (PSP) is a 4-repeat tauopathy characterised by neuronal loss in the subthalamic nucleus, substantia nigra, globus pallidus, and pons, with tau-positive globose neurofibrillary tangles and tuft-shaped astrocytes on immunohistochemistry. Clinically it presents with vertical gaze palsy, falls, and parkinsonism unresponsive to levodopa. Parkinson disease has alpha-synuclein Lewy bodies; Alzheimer disease has paired helical filament tau tangles predominantly in the medial temporal lobe.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.