Disease-Specific Metabolic Patterns in Progressive Supranuclear Palsy with Richardson's Syndrome and Variants: A...

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Progressive supranuclear palsy (PSP) is a rare tauopathy with diverse clinical presentations.
• The PSP-related metabolic pattern (PSPRP) aids in distinguishing PSP from other parkinsonian syndromes.
• Type-specific metabolic patterns in PSP phenotypes require further characterization.

Purpose of the Study:

• To identify distinct metabolic patterns for each PSP subtype.
• To assess the utility of these patterns in monitoring disease progression.
• To evaluate their ability to predict conversion from variant PSP (vPSP) to PSP with Richardson's syndrome (PSP-RS).

Main Methods:

• ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET imaging was used for PSP-RS, PSP-P, PSP-PGF, and PSP-PI.
• Scaled subprofile modeling/principal-component analysis identified type-specific patterns (PGFRP, PIRP).
• Evaluated pattern similarity to PSPRP, classification ability, and longitudinal predictive value for vPSP to PSP-RS conversion.

Main Results:

• Type-specific patterns showed topographic similarity and association with PSPRP.
• The PSP-PGF-related pattern (PGFRP) involved the striatum more extensively.
• Patterns effectively distinguished PSP-RS from vPSP, increased with follow-up, correlated with clinical progression, and predicted vPSP to PSP-RS conversion.

Conclusions:

• PSP phenotypes possess unique metabolic covariance patterns with overlap but also distinct features compared to PSPRP.
• These type-specific patterns are valuable for tracking PSP progression over time.
• The identified patterns show potential for predicting clinical conversion in vPSP.