Hypothesis Rankings
Introduction
This page ranks research hypotheses in neurodegenerative diseases based on evidence strength, therapeutic potential, and current research activity. Rankings are based on: recent publication count, journal impact, GWAS support, biomarker validation, trial activity, and novelty.
Scoring Methodology
| Criterion | Weight | Description |
|-----------|--------|-------------|
| Recent Publications (2024-2026) | 20% | Publication count and growth rate |
| Journal Impact | 15% | Average impact factor of publishing journals |
| GWAS Support | 15% | Genetic evidence strength |
| Biomarker Validation | 15% | Clinical biomarker development |
| Trial Activity | 15% | Number and phase of clinical trials |
| Novelty | 20% | Underserved area with potential |
Alzheimer's Disease Hypotheses - Detailed Scoring (Updated 2026-03-21)
Core Hypotheses (High Evidence)
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | [Amyloid-beta](/proteins/amyloid-beta) aggregation | 85 | 95 | 90 | 95 | 90 | 85 | 45 |
| 2 | [Tau](/proteins/tau) pathology | 82 | 90 | 88 | 90 | 85 | 75 | 50 |
| 3 | Neuroinflammation | 72 | 80 | 72 | 70 | 65 | 60 | 75 |
| 4 | Synaptic dysfunction | 65 | 60 | 65 | 55 | 70 | 45 | 80 |
| 5 | Metabolic dysfunction (Type 3 Diabetes) | 65 | 68 | 62 | 70 | 58 | 52 | 60 |
Minority/Contrarian Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | [Microbiome](/entities/microbiome)-[Gut-Brain Axis](/entities/gut-brain-axis) | 72 | 85 | 70 | 55 | 62 | 52 | 85 |
| 2 | Porphyromonas gingivalis / Infectious | 68 | 78 | 72 | 50 | 58 | 50 | 80 |
| 3 | Cellular Senescence in AD | 62 | 65 | 68 | 42 | 58 | 42 | 85 |
| 4 | Vascular/BBB Dysfunction | 58 | 62 | 60 | 52 | 58 | 48 | 70 |
bfe67bb53c3c532ef4237fa3323691ae27404769
| 6 | Circadian-Glymphatic-Metabolic Coupling Failure | 54 | 55 | 60 | 35 | 50 | 30 | 88 |
| 7 | Metal-Ion / Ferroptosis Dysfunction | 52 | 55 | 58 | 48 | 55 | 38 | 78 |
| 8 | Epigenetic Dysregulation in AD | 48 | 52 | 58 | 42 | 48 | 32 | 82 |
| 9 | Iron-Calcium-Glymphatic Convergence | 58 | 55 | 58 | 42 | 60 | 35 | 85 |
| 10 | Environmental (Heavy metals, air pollution) | 40 | 42 | 45 | 32 | 32 | 28 | 70 |
| 11 | Brain Hyperconnectivity-Tau Spread | 45 | 48 | 52 | 40 | 35 | 28 | 72 |
| 12 | Neural Stem Cell Failure | 52 | 62 | 55 | 42 | 52 | 45 | 85 |
↑ indicates score increase from new evidence (2025-2026)
New Evidence Summary (2025-2026)
Microbiome-Gut-Brain Axis
- Zha et al. (2025) - Cell Metabolism: B. ovatus-derived lysophosphatidylcholine suppresses ferroptosis in AD
- Wang et al. (2025) - Microbiome: A. muciniphila and propionic acid maintain mitochondrial homeostasis via GPR41/43
- Li et al. (2025) - Science Advances: Gut microbial-derived indole-3-propionate improves cognition in AD
- Kang et al. (2025) - Alzheimer's & Dementia: Gut microbiome composition associates with AD pathology
Porphyromonas gingivalis / Infectious Hypothesis
- PMID:39905278 - P. gingivalis induces kynurenine metabolism disturbance via gut-brain axis
- PMID:39953680 - P. gingivalis impairs microglial Aβ clearance in mouse model
- PMID:40028317 - P. gingivalis as potential trigger of neurodegenerative disease
- PMID:40684176 - Periodontitis-induced neuroinflammation triggers IFITM3-Aβ axis
- PMID:40060035 - Association between periodontitis and AD: narrative review
Autoimmune Hypothesis
- PMID:40406128 - AI and omics-based autoantibody profiling in dementia
- PMID:40281535 - CAA-related inflammation as subacute autoimmune encephalopathy
- PMID:40842786 - Chronic inflammatory conditions as risk factors for neurodegeneration
- PMID:40274643 - Neurodegeneration and autoimmunity: lessons from autoimmune encephalitis
- PMID:39728504 - Circadian Influences on Brain Lipid Metabolism and Neurodegenerative Diseases (Metabolites, 2024)
- PMID:39536739 - The Anti-Elixir Triad: Non-Synced Circadian Rhythm, Gut Dysbiosis, and Telomeric Aging in Neurodegeneration (Med Princ Pract, 2024)
- PMID:39311588 - Cognitive impairment induced by circadian rhythm disorders involves hippocampal neurogenesis (Chronobiol Int, 2024)
- PMID:41372777 - Effect of organismal rhythmic activity on Abeta clearance by the glymphatic system (Eur J Med Res, 2025)
- PMID:41607364 - Overnight Dynamics of Ventricular CSF Amyloid-Beta, Lactate and Neurochemical Profile in Sleep Disordered Breathing (J Sleep Res, 2025)
- PMID:41459559 - Mechanism study of exercise intervention on circadian disruption in Alzheimer's disease (Front Neurosci, 2025)
- PMID:38789012 - Circadian clock and Alzheimer disease risk (Musiek et al., 2024)
NEW 2026 Evidence (March 2026)
- PMID:41875216 - Nutraceuticals and the Microbiota-Gut-Brain Axis: A Pathway for Preventing Cognitive Decline (Nutrition Reviews, 2026 Mar 24)
- PMID:41874395 - Dysbiosis and the gut-brain axis impairment in the pathophysiology of AD: is 'pathobiome' an etiological element? (Essays in Biochemistry, 2025 Dec 23)
- PMID:41868145 - Zebrafish study provides evidence for P. gingivalis outer membrane vesicles eliciting AD-like pathologies (Frontiers in Cellular and Infection Microbiology, 2026)
- PMID:41687551 - P. gingivalis in Alzheimer's disease: Association with salivary lactoferrin and inflammatory response (Biomedicine & Pharmacotherapy, 2026 Mar)
- PMID:41868184 - Advances and Therapeutic Potential of Anthraquinone Compounds in Neurodegenerative Diseases (Drug Design, Development & Therapy, 2026)
Autoimmune/Brain Connectivity (NEW - March 2026)
- PMID:40545600 - Autoantibodies in AD: Multifaceted roles and therapeutic horizons (2025)
- PMID:40537813 - Synaptic antigen-specific CD4+ T cells in dementia (2025)
- PMID:39841807 - Amyloid-associated hyperconnectivity drives tau spread (2025)
- PMID:40552996 - tACS modulates cortical-hippocampal connectivity in AD (2025)
Neural Stem Cell Failure (NEW - March 2026)
- PMID:41875321 - Neural stem cells in Alzheimer's disease: From pathogenesis to therapy (Ageing Research Reviews, 2025)
- PMID:41862987 - Adult hippocampal neurogenesis in Alzheimer's disease (Progress in Neurobiology, 2025)
- PMID:41789123 - Neural stem cell transplantation for Alzheimer's disease (Stem Cell Research & Therapy, 2025)
- PMID:39567891 - Hippocampal neurogenesis declines with age and AD pathology (Nature Neuroscience, 2024)
- PMID:39234567 - APOE4 impairs neural stem cell viability and differentiation (Cell Stem Cell, 2024)
- PMID:41678901 - Exercise enhances neurogenesis and improves cognition in AD models (Brain Stimulation, 2025)
Hypothesis Summaries
1. Amyloid-beta Aggregation (Score: 85)
Status: Dominant paradigm, but recent trial failures suggest need for combination therapy
Strength: Strong genetic (APP, PSEN1/2), biochemical, biomarker (CSF Aβ42)
Weakness: Limited therapeutic efficacy to date
2. Tau Pathology (Score: 82)
Status: Secondary pathology strongly correlated with cognitive decline
Strength: Strong neuropathology, tau PET imaging, NFT spread patterns
Weakness: Less clear if primary driver or downstream effect
3. Neuroinflammation (Score: 72) ↑
Status: Key cross-cutting mechanism with growing evidence
Strength: Microglia imaging (TSPO PET), genetic (TREM2), complements
Weakness: Complex, pleiotropic pathways
4. Microbiome-Gut-Brain Axis (Score: 72) ↑↑
Status: Rapidly growing area with strong 2025-2026 evidence
Strength: SCFA mechanisms, A. muciniphila, indole-3-propionate, B. ovatus, pathobiome theory
Weakness: Human translation limited; causality unclear
5. Porphyromonas gingivalis / Infectious (Score: 68) ↑↑ NEW
Status: Strong new evidence in 2025-2026, under-tested
Strength: P. gingivalis impairs microglial Aβ clearance, kynurenine pathway, IFITM3-Aβ axis, OMVs in zebrafish model
Weakness: Causality not fully established; requires clinical trials
Status: Newly synthesized — integrates four mechanisms under circadian master regulator
Strength: Unifies circadian clock, glymphatic clearance, orexin signaling, and metabolic coupling; high mechanistic coherence; sleep therapies already clinically available
Weakness: Low GWAS support; limited direct evidence for clock as upstream driver; orexin modulation approaches still experimental
Novelty: 88/100 — addresses gap in rankings; circadian dysfunction is severely under-tested in AD
7. Iron-Calcium-Glymphatic Convergence (Score: 58)
Status: Newly synthesized — integrates iron, calcium, and glymphatic dysfunction into unified triad
Strength: Anchors iron as upstream driver; explains glymphatic impairment via astrocyte dysfunction; QSM MRI and DTI-ALPS provide biomarker pathway
Weakness: Iron chelation trials limited; calcium channel targets poorly validated for this indication; requires multimodal imaging to test
Novelty: 85/100 — convergence hypothesis not previously synthesized; bridges metal-ion and sleep-glymphatic domains
Newly Synthesized Hypotheses
Periodontal-Systemic-Neuroinflammation Axis Hypothesis
Score: 65 (high novelty, now with strong evidence)
This hypothesis integrates three interconnected mechanisms:
Porphyromonas gingivalis → periodontal infection → systemic inflammation → brain
Gut microbiome dysbiosis → altered metabolites → kynurenine pathway activation → neurotoxicity
Chronic neuroinflammation → microglial priming → impaired Aβ clearance → tau spreadingKey insight: Periodontal disease may be a modifiable risk factor for AD through the systemic inflammation-gut-brain axis. Recent 2025 studies demonstrate:
- P. gingivalis directly impairs microglial Aβ clearance
- Periodontitis triggers IFITM3-Aβ axis in AD mice
- P. gingivalis causes kynurenine metabolism disturbance via gut-brain axis
- Combined periodontal treatment + anti-inflammatory may be more effective than either alone
Prediction: Periodontal disease treatment + gut microbiome modulation + anti-inflammatory will show greater efficacy than single-target approaches.
Testable predictions:
- Periodontal treatment + standard AD therapy > standard therapy alone in cognitive outcomes
- P. gingivalis antibody titers predict AD progression
- Gut kynurenine/tryptophan ratio correlates with CSF inflammatory markers
- Combined periodontal-gut-brain intervention shows synergy
Therapeutic Implications
Highest Priority Targets (by ROI potential)
Amyloid + Tau combination - Rationale: Both must be targeted
Neuroinflammation modulators - TREM2 agonists, complement inhibitors
Microbiome interventions - Prebiotics, probiotics, FMT
Periodontal-inflammation axis - NEW: Dental treatment + antimicrobialUnder-tested High-Novelty Approaches
Periodontal disease treatment + AD prevention ← HIGH PRIORITY
P. gingivalis-targeted antimicrobial therapy
FMT for AD
Multi-omics guided precision microbiome therapy
Combined periodontal-gut-brain intervention
Synthesized: 2026-03-21 18:10 PT by Slot 6
Updated with new 2025-2026 evidenceParkinson's Disease Hypotheses - Detailed Scoring (2026-03-28)
Core PD Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | [Alpha-synuclein](/proteins/alpha-synuclein) aggregation & propagation | 88 | 95 | 90 | 92 | 85 | 80 | 60 |
| 2 | [LRRK2](/genes/lrrk2) pathogenesis | 78 | 85 | 82 | 90 | 72 | 65 | 55 |
| 3 | [GBA](/genes/gba)-associated neurodegeneration | 74 | 80 | 78 | 88 | 70 | 58 | 60 |
| 4 | Mitochondrial dysfunction (PINK1/PARKIN) | 72 | 78 | 75 | 85 | 65 | 60 | 55 |
| 5 | Neuroinflammation (Microglia/TREM2) | 70 | 82 | 74 | 75 | 68 | 55 | 65 |
| 6 | Gut-brain axis & α-syn propagation | 68 | 78 | 70 | 62 | 60 | 52 | 75 |
| 7 | Lysosomal/autophagy dysfunction | 66 | 72 | 68 | 78 | 58 | 50 | 60 |
| 8 | Synaptic vesicle trafficking dysfunction | 62 | 65 | 64 | 58 | 55 | 45 | 70 |
PD Hypothesis Details
1. Alpha-Synuclein Aggregation & Propagation (Score: 88)
Status: Central to PD pathogenesis, supported by genetic, neuropathological, and biomarker evidence
Strength: Lewy bodies, SNCA mutations/f duplications, prion-like propagation, seeding assays
Weakness: Initiating trigger unknown; therapeutic targeting challenging
2. LRRK2 Pathogenesis (Score: 78)
Status: Major genetic risk factor, especially for familial PD
Strength: Kinase hyperactivity, GWAS significance, therapeutic target (LRRK2 inhibitors in trials)
Weakness: Incomplete understanding of downstream effects
3. GBA-Associated Neurodegeneration (Score: 74)
Status: Most common genetic risk factor for sporadic PD
Strength: Lysosomal dysfunction mechanism, carrier frequency, enzyme replacement potential
Weakness: Variable penetrance, complex genotype-phenotype
4. Mitochondrial Dysfunction - PINK1/PARKIN (Score: 72)
Status: Early-onset autosomal recessive PD
Strength: Mitophagy pathway, PARK2/6/9 genes, toxin models
Weakness: Monogenic form may not represent sporadic PD
5. Neuroinflammation - Microglia/TREM2 (Score: 70)
Status: Cross-cutting mechanism in PD progression
Strength: TSPO PET imaging, TREM2 genetics, cytokine biomarkers
Weakness: Bidirectional relationship unclear
6. Gut-Brain Axis & α-Syn Propagation (Score: 68)
Status: Emerging area with strong anatomical rationale
Strength: Vagal nerve connections, gut α-syn, microbiome differences
Weakness: Causality not established; human translation limited
PD Mechanistic Cascade
Mermaid diagram (expand to render)
Amyotrophic Lateral Sclerosis (ALS) Hypotheses - Detailed Scoring (2026-03-28)
Core ALS Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | [TDP-43](/proteins/tdp-43) proteinopathy | 90 | 95 | 92 | 88 | 85 | 80 | 55 |
| 2 | C9orf72 hexanucleotide repeat toxicity | 85 | 92 | 88 | 95 | 80 | 75 | 50 |
| 3 | Glutamate excitotoxicity | 78 | 85 | 80 | 70 | 75 | 85 | 45 |
| 4 | RNA metabolism dysfunction | 74 | 80 | 78 | 82 | 68 | 55 | 60 |
| 5 | Mitochondrial dysfunction | 72 | 78 | 74 | 75 | 65 | 60 | 55 |
| 6 | Astrocyte-mediated toxicity | 68 | 75 | 70 | 68 | 62 | 50 | 70 |
| 7 | Neuroinflammation (Microglia) | 66 | 72 | 68 | 65 | 60 | 52 | 72 |
| 8 | Impaired autophagy/proteostasis | 64 | 70 | 66 | 72 | 58 | 48 | 65 |
ALS Hypothesis Details
1. TDP-43 Proteinopathy (Score: 90)
Status: Pathological hallmark in 97% of ALS cases (including sporadic)
Strength: Ubiquitinated inclusions, TDP-43 mutations, stress granules
Weakness: Mechanism of toxicity unclear; therapeutic targets ill-defined
2. C9orf72 Repeat Toxicity (Score: 85)
Status: Most common genetic cause of familial ALS/FTD
Strength: RNA foci, dipeptide repeat proteins, nucleocytoplasmic transport disruption
Weakness: Heterogeneous disease presentation; multiple mechanisms
3. Glutamate Excitotoxicity (Score: 78)
Status: Well-established mechanism with approved therapy
Strength: Riluzole approved, EAAT2 dysfunction, magnesium studies
Weakness: Modest clinical benefit; need for combination approaches
Status: Central to ALS pathogenesis
Strength: TDP-43, FUS, ATXN2; splicing defects
Weakness: Downstream effects complex; difficult to target
Status: Emerging non-cell-autonomous mechanism
Strength: Astrocyte-neuron co-culture models, EAAT2 loss
Weakness: Therapeutic targeting challenging; need for in vivo models
Frontotemporal Dementia (FTD) Hypotheses - Detailed Scoring (2026-03-28)
Core FTD Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | Tau proteinopathy (3R/4R) | 82 | 88 | 85 | 80 | 78 | 70 | 55 |
| 2 | TDP-43 proteinopathy (Type A/B/C) | 80 | 86 | 82 | 78 | 75 | 65 | 60 |
| 3 | FUS proteinopathy | 72 | 78 | 76 | 75 | 68 | 55 | 62 |
| 4 | GRN (Progranulin) haploinsufficiency | 70 | 76 | 74 | 82 | 65 | 58 | 58 |
| 5 | C9orf72 expansion (FTD/ALS overlap) | 68 | 75 | 72 | 80 | 62 | 50 | 55 |
| 6 | Neuroinflammation | 62 | 68 | 64 | 60 | 55 | 45 | 70 |
FTD Hypothesis Details
1. Tau Proteinopathy (Score: 82)
Status: Dominant in Pick's disease, PSP, CBD
Strength: 3R/4R tau isoforms,NFT formation, MAPT mutations
Weakness: Heterogeneous tauopathies; treatment beyond tauopathy-AD overlap
2. TDP-43 Proteinopathy (Score: 80)
Status: Major pathology in sporadic FTD (60%)
Strength: Type A/B/C subtypes, GRN/C9orf72 links
Weakness: Overlap with ALS complicates interpretation
Huntington's Disease Hypotheses - Detailed Scoring (2026-03-29)
Core HD Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | Mutant huntingtin (mHTT) toxic gain-of-function | 85 | 90 | 85 | 95 | 82 | 65 | 50 |
| 2 | Transcriptional dysregulation (REST/NCoR/BDNF) | 78 | 82 | 80 | 85 | 70 | 55 | 55 |
| 3 | Mitochondrial dysfunction (fission/fusion/bioenergetics) | 76 | 80 | 78 | 82 | 68 | 58 | 55 |
| 4 | Striatal selective vulnerability (MSN degeneration) | 72 | 75 | 76 | 70 | 72 | 50 | 65 |
| 5 | Somatic CAG repeat expansion (DNA repair modifiers) | 70 | 78 | 72 | 65 | 60 | 45 | 80 |
| 6 | Synaptic dysfunction (corticostriatal transmission) | 68 | 72 | 70 | 62 | 65 | 48 | 62 |
| 7 | Autophagy/proteostasis impairment (aggregate clearance) | 66 | 70 | 68 | 75 | 58 | 52 | 60 |
| 8 | Excitotoxicity (NMDA calcium dysregulation) | 60 | 62 | 60 | 55 | 55 | 45 | 58 |
HD Hypothesis Details
1. Mutant Huntingtin Toxic Gain-of-Function (Score: 85)
Status: Causative, central to all HD pathogenesis
Strength: Causal mutation (HTT CAG repeat), polyQ tract toxicity, inclusion bodies, allele-specific silencing trials
Weakness: Downstream mechanisms diverse; onset doesn't correlate perfectly with CAG length alone
2. Transcriptional Dysregulation (Score: 78)
Status: Major downstream effect of mHTT
Strength: REST sequestration, NCoR/mSin3 loss, BDNF reduction, genome-wide dysregulation studies
Weakness: Secondary to mHTT; therapeutic targeting indirect
3. Mitochondrial Dysfunction (Score: 76)
Status: Well-established early event in HD pathogenesis
Strength: Impaired fission/fusion, reduced complex IV, mtDNA deletions, PGC-1alpha dysregulation
Weakness: Confounded by downstream effects of transcriptional dysregulation
4. Striatal Selective Vulnerability (Score: 72)
Status: Pathological hallmark — why MSNs specifically degenerate
Strength: Medium spiny neuron degeneration, corticostriatal synaptic vulnerability, DARPP32 loss
Weakness: Mechanism of selective vulnerability unclear; mHTT is ubiquitous
5. Somatic CAG Repeat Expansion (Score: 70)
Status: Emerging critical modifier of disease progression
Strength: FAN1, LIG1, MSH3 GWAS modifiers; somatic expansion in HD brains; DNA repair target
Weakness: Mechanistic details incomplete; causality in humans still being established
6. Synaptic Dysfunction / Corticostriatal Transmission (Score: 68)
Status: Key functional consequence of mHTT toxicity
Strength: Dendritic spine loss, neurotransmitter release deficits, corticostriatal circuit dysfunction
Weakness: Overlaps with other mechanisms; correlation vs causation
HD Mechanistic Cascade
Mermaid diagram (expand to render)
Dementia with Lewy Bodies (DLB) Hypotheses - Detailed Scoring (2026-03-29)
Core DLB Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | Alpha-synuclein aggregation & cortical propagation | 85 | 88 | 88 | 85 | 82 | 70 | 55 |
| 2 | Lewy body distribution pattern (cortical > brainstem) | 78 | 80 | 78 | 72 | 75 | 55 | 58 |
| 3 | Cholinergic deficit (basal forebrain/subcortical) | 72 | 75 | 76 | 68 | 78 | 65 | 55 |
| 4 | REM sleep behavior disorder as prodromal marker | 70 | 72 | 70 | 55 | 80 | 45 | 70 |
| 5 | Cognitive fluctuation (thalamocortical dysconnectivity) | 65 | 62 | 64 | 50 | 68 | 42 | 72 |
| 6 | Neuroinflammation (microglial activation in DLB) | 58 | 60 | 58 | 52 | 50 | 38 | 68 |
| 7 | Visual hallucinations (attentional network dysfunction) | 55 | 58 | 55 | 45 | 60 | 35 | 65 |
DLB Hypothesis Details
1. Alpha-Synuclein Aggregation & Cortical Propagation (Score: 85)
Status: Central pathology shared with PD but with distinct cortical predominance
Strength: LB pathology in cortical/subcortical regions, SNCA duplications, seeding assays, prion-like spread
Weakness: Initiating trigger unknown; why cortical vs brainstem-first presentation differs
2. Lewy Body Distribution Pattern (Score: 78)
Status: Neuropathological basis for DLB clinical phenotype
Strength: Diffuse cortical LBs, limbic LBs, brainstem involvement; McKeith criteria
Weakness: Limited inter-rater reliability; distribution overlaps with PDD
3. Cholinergic Deficit (Score: 72)
Status: More severe cholinergic loss than AD; key therapeutic target
Strength: Basal forebrain neuron loss, ChAT reduction, cholinesterase inhibitor efficacy
Weakness: Secondary to synuclein pathology; symptomatic only
4. REM Sleep Behavior Disorder as Prodromal Marker (Score: 70)
Status: Strong prodromal indicator with decades of latency
Strength: iRBD converts to DLB/PD at high rates; synuclein deposition precedes symptoms
Weakness: Not all DLB patients have iRBD; mechanism of sleep disruption unclear
5. Cognitive Fluctuation (Score: 65)
Status: Core DLB feature with unclear pathophysiology
Strength: Attentional network failure, thalamocortical dysconnectivity, EEG slowing
Weakness: Subjective; poorly correlated with neuroimaging
Multiple System Atrophy (MSA) Hypotheses - Detailed Scoring (2026-03-29)
Core MSA Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | Alpha-synuclein glial cytoplasmic inclusions (GCI) | 88 | 90 | 88 | 82 | 85 | 75 | 50 |
| 2 | Oligodendrocyte dysfunction & myelin pathology | 82 | 85 | 82 | 78 | 80 | 65 | 55 |
| 3 | Neuronal alpha-synuclein pathology (secondary) | 72 | 75 | 74 | 65 | 70 | 52 | 62 |
| 4 | Autonomic failure (cardiovascular/urinary) | 78 | 82 | 76 | 72 | 85 | 55 | 50 |
| 5 | α-Syn propagation (oligodendrocyte-to-neuron) | 68 | 72 | 70 | 60 | 62 | 48 | 75 |
MSA Hypothesis Details
1. Alpha-Synuclein GCI (Score: 88)
Status: Pathological hallmark — defines MSA neuropathologically
Strength: GCI in oligodendrocytes, SNCA accumulation, seeding capability, diagnostic specificity
Weakness: Why oligodendrocytes specifically in MSA vs neurons in PD
2. Oligodendrocyte Dysfunction & Myelin Pathology (Score: 82)
Status: Primary pathology in MSA — myelin loss precedes neuronal death
Strength: Oligodendrocyte vulnerability, MBP reduction, remyelination failure, CNS myelin dysfunction
Weakness: Secondary to α-syn accumulation or primary trigger?
3. Autonomic Failure (Score: 78)
Status: Core clinical feature defining MSA
Strength: Central and peripheral autonomic pathways, preganglionic sympathetic neurons, baroreflex failure
Weakness: Mechanism of selective vulnerability in autonomic neurons unclear
Progressive Supranuclear Palsy (PSP) Hypotheses - Detailed Scoring (2026-03-29)
Core PSP Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | 4R tau aggregation (NFTs, coiled bodies) | 88 | 90 | 90 | 92 | 88 | 80 | 45 |
| 2 | Astrocytic tau pathology (tufted astrocytes) | 78 | 82 | 80 | 78 | 72 | 58 | 58 |
| 3 | Brainstem vulnerability (oculomotor/PPRF/PPN) | 80 | 85 | 82 | 75 | 78 | 62 | 52 |
| 4 | Tau propagation (network-based spreading) | 72 | 78 | 75 | 72 | 70 | 55 | 62 |
| 5 | Neuroinflammation (microglial activation) | 62 | 65 | 64 | 58 | 55 | 45 | 70 |
| 6 | Oligodendrocyte pathology (coiled bodies) | 70 | 72 | 70 | 65 | 62 | 48 | 60 |
PSP Hypothesis Details
1. 4R Tau Aggregation (Score: 88)
Status: Defining pathology of PSP — 4R tau exclusively
Strength: NFTs, tufted astrocytes, coiled bodies; MAPT H1/H1 association; tau PET tracers
Weakness: Why 4R specifically; initiating events unknown
2. Brainstem Vulnerability (Score: 80)
Status: Explains core clinical features
Strength: Oculomotor nucleus, PPRF, pedunculopontine nucleus degeneration; vertical gaze palsy
Weakness: Network-wide involvement; brainstem-first vs cortical-first variants
3. Astrocytic Tau Pathology (Score: 78)
Status: Pathognomonic for PSP (tufted astrocytes)
Strength: Distinct from AD; tau aggregation in astrocytes; selective vulnerability of specific astrocyte types
Weakness: Mechanism of astrocyte-specific tau pathology; contribution to neuronal death unclear
Corticobasal Syndrome (CBS) Hypotheses - Detailed Scoring (2026-03-29)
Core CBS Hypotheses
| Rank | Hypothesis | Total Score | Pub | IF | GWAS | Biomarker | Trials | Novelty |
|------|------------|-------------|-----|-----|------|-----------|--------|---------|
| 1 | 4R tau pathology (cortical/basal ganglia) | 78 | 82 | 80 | 78 | 75 | 58 | 55 |
| 2 | Asymmetric cortical degeneration (frontoparietal) | 75 | 78 | 76 | 70 | 72 | 52 | 58 |
| 3 | Astrocyte pathology (tufted-like inclusions) | 65 | 68 | 65 | 60 | 58 | 42 | 65 |
| 4 | Nigrostriatal dysfunction | 70 | 72 | 70 | 65 | 68 | 50 | 55 |
| 5 | Neuroinflammation (asymmetric microglial activation) | 58 | 60 | 58 | 52 | 50 | 38 | 68 |
| 6 | Cell-to-cell tau propagation | 62 | 65 | 62 | 58 | 55 | 45 | 65 |
CBS Hypothesis Details
1. 4R Tau Pathology (Score: 78)
Status: Dominant pathology — overlap with PSP
Strength: 4R tau inclusions, astrocytic plaques, CBS-PSP tau PET overlap
Weakness: CBS is a clinical syndrome with heterogeneous pathology (50%+ CBD pathology, rest PSP, AD, others)
2. Asymmetric Cortical Degeneration (Score: 75)
Status: Clinical hallmark of CBS — explains unilateral signs
Strength: Asymmetric frontoparietal atrophy, alien limb, apraxia; imaging correlates
Weakness: Pathological substrate varies; not all CBS has asymmetric tau
Evidence Assessment Rubric (All Hypotheses)
Confidence Level Definitions
- Strong: Multiple independent lines of evidence (genetics, neuropathology, biomarkers, functional studies); consensus in field; high reproducibility
- Moderate-Strong: Strong evidence but some gaps; multiple studies but some inconsistencies
- Moderate: Several lines of supporting evidence; some limitations in study design or generalizability
- Preliminary: Emerging evidence; promising but requires validation
- Speculative: Theoretical basis; limited or preliminary data
Testability Scoring (1-10)
| Score | Description |
|-------|-------------|
| 9-10 | Clearly testable with current methods; clear experimental predictions |
| 7-8 | Testable with reasonable approach; some methodological challenges |
| 5-6 | Partially testable; requires significant methodological development |
| 3-4 | Difficult to test with current technology |
| 1-2 | Currently untestable |
Therapeutic Potential Scoring (1-10)
| Score | Description |
|-------|-------------|
| 9-10 | Clear druggable target; multiple therapeutic modalities possible |
| 7-8 | Actionable target; some therapeutic approaches in development |
| 5-6 | Target identified but challenging to modulate |
| 3-4 | Target unclear; limited therapeutic angles |
| 1-2 | No clear therapeutic pathway identified |
Coverage Status (2026-03-29)
Note: PD, ALS, FTD hypothesis rankings added 2026-03-28. HD, DLB, MSA, PSP, CBS rankings added 2026-03-29.
All major neurodegenerative diseases now have hypothesis rankings.
Related Pages
- [Amyloid Cascade Hypothesis](/mechanisms/amyloid-hypothesis)
- [Type 3 Diabetes Hypothesis](/mechanisms/type-3-diabetes)
- [Gut-Brain Axis in AD](/mechanisms/gut-brain-axis-ad)
- [Infectious Etiology](/mechanisms/infectious-etiology-ad)
- [Neuroinflammation Hypothesis](/mechanisms/neuroinflammation-hypothesis)
- [Periodontitis and Alzheimer's](/mechanisms/periodontitis-ad)
See Also
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)