A 65-year-old man presents with progressive difficulty walking, frequent falls, and inability to look down at his feet. Examination reveals axial rigidity, frontal release signs, and impaired vertical saccades, worse for downward gaze. The most likely diagnosis is:
- A Parkinson disease
- B Progressive supranuclear palsy ✓
- C Multiple system atrophy
- D Corticobasal degeneration
Correct answer: B. Progressive supranuclear palsy
Explanation
Progressive supranuclear palsy (PSP) is characterized by early postural instability with falls, axial rigidity, and vertical gaze palsy (especially downward gaze). The gaze palsy is due to lesions in the rostral interstitial nucleus of the medial longitudinal fasciculus and riMLF. Parkinson disease typically has resting tremor, asymmetric onset, and preserved eye movements early. MSA features autonomic dysfunction and cerebellar signs.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.