Progressive Supranuclear Palsy Medical Slides

Present red flags for PSP over PD: early falls within the first year (backward), vertical supranuclear gaze palsy (initially slow downward saccades), symmetric onset (PD is asymmetric), axial-predominant rigidity (PD is appendicular), poor levodopa response (<30% improvement), frontal-executive cognitive changes early, and pseudobulbar affect. Emphasize that the PSP-Parkinsonism phenotype can initially mimic PD, making longitudinal follow-up and re-evaluation essential.

Present two pathognomonic signs: (1) "Hummingbird" or "penguin" sign on midsagittal MRI — midbrain atrophy with preserved pons creating a bird-like silhouette, midbrain AP diameter <9.35 mm, midbrain-to-pons ratio <0.52; (2) "Morning glory" sign on axial view — concavity of the lateral midbrain margin. These have high specificity (>90%) but emerge in advanced disease. SWI sequences showing midbrain T2 hypointensity from iron deposition are an earlier finding.

Organize by the 2017 MDS criteria phenotypic classification: Richardson syndrome (classic PSP with early vertical gaze palsy and falls), PSP-Parkinsonism (asymmetric, tremor, initial levodopa response — mimics PD), PSP-CBS (corticobasal syndrome with apraxia and cortical sensory loss), PSP-SL (speech/language predominant — progressive non-fluent aphasia), and PSP-FTD (behavioral variant frontotemporal dementia features). This taxonomy helps learners recognize that PSP is broader than the classic Richardson presentation.