Macroscopic diagnostic clue for parkinsonism.

Area of Science:

• Neuropathology
• Neurodegenerative Diseases

Background:

• Parkinsonism encompasses diverse neurodegenerative disorders: Lewy body disease (LBD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD).
• Neuropathological diagnosis relies on macroscopic brain assessment for degenerative lesions, guiding microscopic examination.
• Proteinopathies, specifically synucleinopathies (LBD, MSA) and tauopathies (PSP, CBD), underpin these conditions, with glial-predominant forms potentially causing volume reduction.

Purpose of the Study:

• To review macroscopic diagnostic clues for LBD, MSA, PSP, and CBD.
• To aid neuropathologists in refining pathological diagnoses through visual inspection of brain changes.
• To highlight the role of macroscopic findings in differentiating parkinsonism subtypes.

Main Methods:

• Review of neuropathological literature focusing on macroscopic findings in parkinsonian disorders.
• Analysis of disease-specific patterns of brain atrophy and discoloration.
• Correlation of macroscopic observations with underlying proteinopathies (synucleinopathies and tauopathies).

Main Results:

• Macroscopic examination reveals variable atrophy and discoloration indicative of specific neurodegenerative diseases.
• Distinct macroscopic profiles aid in identifying relevant brain regions for microscopic analysis.
• Understanding these visual cues is crucial for accurate pathological classification, despite challenges from disease duration and mixed pathologies.

Conclusions:

• Macroscopic inspection provides essential initial diagnostic clues for parkinsonism subtypes.
• Visual assessment of brain lesions complements microscopic analysis in neuropathology.
• This review offers a guide to macroscopic diagnostic features for improved pathological refinement of LBD, MSA, PSP, and CBD.