Sleep and Circadian Dysfunction as Driver of Neurodegeneration

Experiment: Sleep and Circadian Dysfunction in Neurodegeneration

Rank: 112

Key Question

Is sleep disruption a causal driver of neurodegeneration or merely a downstream marker, and can sleep/circadian restoration slow disease progression?

Background

Sleep disturbances are nearly universal in neurodegenerative diseases, affecting 40-90% of patients with AD, PD, and other disorders. Key questions remain:

Experiment: Sleep and Circadian Dysfunction in Neurodegeneration

Rank: 112

Key Question

Is sleep disruption a causal driver of neurodegeneration or merely a downstream marker, and can sleep/circadian restoration slow disease progression?

Background

Sleep disturbances are nearly universal in neurodegenerative diseases, affecting 40-90% of patients with AD, PD, and other disorders. Key questions remain:

Hypotheses

Validation Protocol

Study Design: Sleep-Circadian-Neurodegeneration (SCAN) Study

Cohort Structure:

| Group | N | Criteria |
|-------|---|----------|
| Subjective cognitive decline with sleep complaints | 100 | Poor sleep, no objective impairment |
| MCI with sleep disorder | 75 | MCI + PSG-confirmed disorder |
| Early AD/PD | 100 | Mild disease + sleep complaints |
| Age-matched good sleep controls | 75 | Normal sleep, no neurodegenerative signs |

Assessments (annual for 4 years):

• Polysomnography (PSG) - full, at baseline and 2 years
• Actigraphy (14 days quarterly)
• Sleep diaries
• Epworth Sleepiness Scale, PSQI

• CSF: Aβ42/40, p-tau181, total tau, α-syn SAA, NfL
• Plasma: NfL, p-tau217, GFAP
• Amyloid PET (Florbetaben)
• Tau PET (MK-6240) in AD cohort
• Dopaminergic PET (FP-CIT) in PD cohort

• AD: MoCA, RBANS, Clinical Dementia Rating
• PD: MDS-UPDRS, Hoehn & Yahr

Key Endpoints

• Primary: Change in neurodegeneration biomarkers per unit of sleep disruption
• Secondary: Does sleep improvement correlate with biomarker stabilization?
• Tertiary: Define sleep-phenotype subtypes within each disease

Model Systems

Animal Models

• Sleep deprivation in 5xFAD mice (amyloid model)
• Sleep fragmentation in P301S tau mice
• Circadian disruption in MPTP/6-OHDA PD model

In Vitro

• Glymphatic clearance assays under sleep-deprived conditions
• Circadian clock gene knockdown in neuronal cultures

Expected Outcomes

Expected Results Timeline

• Year 1: Enrollment complete, baseline biomarkers + PSG
• Year 2: First longitudinal data, sleep-biomarker correlations emerge
• Year 3: Test causality with cross-sectional and longitudinal models
• Year 4: Intervention arm results, mechanistic validation

Feasibility Assessment

| Dimension | Score | Rationale |
|-----------|-------|-----------|
| Mechanistic Impact | 9/10 | Addresses fundamental question of sleep-neurodegeneration relationship |
| Cure Proximity | 7/10 | Sleep interventions are low-risk; could slow progression |
| Feasibility | 8/10 | Standard sleep and biomarker techniques; multi-site |
| Cost Efficiency | 8/10 | Sleep interventions are inexpensive |
| Timeline | 7/10 | 4-year study reasonable |
| Cross-Disease Value | 10/10 | Applicable to AD, PD, ALS, FTD, all neurodegenerative diseases |
| Biomarker Enablement | 9/10 | Sleep measures are biomarkers; correlates with progression |
| Combinability | 9/10 | Sleep intervention can combine with all disease-modifying approaches |
| De-risking Value | 8/10 | Low-risk intervention could benefit millions |
| Novelty | 8/10 | First comprehensive multi-disease sleep-neurodegeneration study |

Total Score: 83/100

Cost Estimate

| Item | Cost |
|------|------|
| Polysomnography (baseline + 2yr) | $1,200,000 |
| Biomarker analysis (CSF + plasma) | $1,800,000 |
| PET imaging | $1,500,000 |
| Actigraphy and sleep monitoring | $400,000 |
| Clinical assessments | $600,000 |
| Data management and analysis | $500,000 |
| Total | $6,000,000 |

References

• Nedergaard M, et al. Sleep drives metabolite clearance from the adult brain. Science. 2013.
• Musiek ES, et al. Circadian clock proteins and neurodegeneration. Nat Rev Neurosci. 2020.
• Ju YE, et al. Sleep and neurodegeneration: A critical appraisal. Lancet Neurol. 2023.

See Also

• [Sleep-Circadian Neurodegeneration Mechanism](/mechanisms/sleep-circadian-neurodegeneration)
• [AD Knowledge Gaps](/gaps/ad-knowledge-gaps-ranked)
• [PD Knowledge Gaps](/gaps/parkinsons)
• [Experiment Priority Index](/experiments/experiment-priority-index)