Alpha-synucleinopathies are a group of neurodegenerative disorders characterized by the accumulation of abnormal alpha-synuclein protein aggregates in the brain. This comparison matrix covers four major alpha-synucleinopathies: Parkinson's Disease (PD), Dementia with Lewy Bodies (DLB), Multiple System Atrophy (MSA), and Progressive Supranuclear Palsy (PSP).
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Year Described | 1817 (James Parkinson) | 1961 (Denong) | 1960 (Menzel) | 1963 (Steele-Richardson-Olszewski) |
| Primary Protein | Alpha-synuclein | Alpha-synuclein | Alpha-synuclein | Tau (4R) |
| Main Pathology | Lewy bodies | Lewy bodies | Glial cytoplasmic inclusions | NFTs, tufted astrocytes |
| Main Gene | SNCA, LRRK2, GBA | SNCA, GBA | SNCA, COQ2 | MAPT |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Core Motor Symptoms | Resting tremor, bradykinesia, rigidity, postural instability | Parkinsonism + hallucinations | Parkinsonism + autonomic failure + cerebellar signs | Vertical gaze palsy, axial rigidity, falls |
| Onset Age (typical) | 60-70 years | 65-80 years | 50-60 years | 60-70 years |
| Disease Duration | 10-20 years | 5-10 years | 5-10 years | 5-10 years |
| Cognitive Decline | Late-stage (PDD) | Early, prominent | Moderate | Early, prominent |
| Hallucinations | Late-stage (drug-induced) | Core feature (recurrent, vivid) | Rare | Rare |
| Autonomic Dysfunction | Mild-moderate (orthostatic hypotension, constipation) | Prominent | Severe (orthostatic hypotension, urinary dysfunction) | Moderate |
| Cerebellar Signs | Rare | Rare | Common (ataxia, nystagmus) | Rare |
| Sleep Disorders | RBD common | RBD common (80%) | RBD common | Night-time behaviors |
| Treatment Response | Good to dopaminergic therapy | Variable, sensitive to antipsychotics | Poor | Poor |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Sporadic Cases | ~90% | ~80% | ~70% | ~95% |
| Familial Cases | ~10% | ~20% | ~30% | ~5% |
| Major Risk Genes | SNCA, LRRK2, GBA, PARKIN, PINK1, DJ-1 | SNCA, GBA, APOE | SNCA, COQ2, GBA | MAPT, STX6, MOPB |
| Inheritance Pattern | Mostly complex | Complex or autosomal dominant | Usually sporadic | Usually sporadic |
| Penetrance | Incomplete | Variable | Variable | Low |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Key Inclusions | Lewy bodies (neuronal) | Cortical Lewy bodies | Glial cytoplasmic inclusions (GCIs) | NFTs, tufted astrocytes |
| Location | Substantia nigra, cortex | Cortex, limbic, brainstem | Basal ganglia, cerebellum, olivary nuclei | Brainstem, basal ganglia, cortex |
| Cell Loss | Substantia nigra dopaminergic | Variable | Multi-system atrophy | Substantia nigra, globus pallidus |
| Neurotransmitter Affected | Dopamine | Dopamine, acetylcholine | Multiple (dopamine, norepinephrine) | Dopamine, GABA |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Motor Symptoms | Levodopa, dopamine agonists, MAO-B inhibitors | Levodopa (variable response) | Levodopa (often poor response) | Limited response |
| Cognitive Symptoms | Cholinesterase inhibitors | Cholinesterase inhibitors (first-line) | No approved therapy | Limited options |
| Autonomic | Midodrine, fludrocortisone | Supportive care | Supportive care | Limited options |
| Disease-Modifying | None approved | None approved | None approved | None approved |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Imaging | DaTscan (reduced dopamine uptake) | Reduced uptake, occipital hypometabolism | Reduced uptake + autonomic testing | MRI: midbrain atrophy |
| CSF | Alpha-synuclein (reduced) | Alpha-synuclein, tau | Alpha-synuclein (reduced) | Tau elevated |
| Sleep | RBD on polysomnography | RBD (core feature) | RBD common | Sleep fragmentation |
| Feature | Parkinson's Disease | Dementia with Lewy Bodies | Multiple System Atrophy | Progressive Supranuclear Palsy |
|---|---|---|---|---|
| Hallmark Sign | Resting tremor | Visual hallucinations | Autonomic failure + cerebellar | Vertical supranuclear gaze palsy |
| Disease Course | Slow progression | Fluctuating course | Rapid progression | Rapid progression |
| Response to Levodopa | Good | Variable | Usually poor | Poor |