SUMMARY
# Sleep and Respiratory Network Interaction in ALS — Experiment Design
## Background and Rationale
Amyotrophic Lateral Sclerosis (ALS) is characterized by progressive motor neuron degeneration, but emerging evidence suggests that sleep and respiratory dysfunction may represent early pathophysiological changes rather than merely late-stage complications. The brainstem regions controlling sleep-wake cycles and respiratory rhythm generation share anatomical proximity and neurochemical pathways, yet
METHODOLOGY NOTES
Phase 1 (Months 1-3): Recruit 120 participants across four groups: early-stage ALS (n=40, ALSFRS-R >35), intermediate ALS (n=40, ALSFRS-R 25-35), advanced ALS (n=20, ALSFRS-R <25), and age-matched controls (n=20). Obtain informed consent and baseline clinical assessments including ALSFRS-R, King's staging, and respiratory symptom questionnaires. Phase 2 (Months 4-18): Conduct comprehensive baseline evaluations every 6 months including overnight polysomnography with respiratory monitoring, pulmonary function testing (FVC, SNIP, MIP), diaphragmatic electromyography, and actigraphy for circadian rhythm assessment. Perform brain and cervical spine MRI with diffusion tensor imaging focusing on brainstem respiratory centers and sleep-wake nuclei. Collect cerebrospinal fluid for neurofilament light chain, phosphorylated tau, and inflammatory markers via lumbar puncture. Phase 3 (Months 19-36): Continue longitudinal follow-up assessments at 6-month intervals with identical protocol. Monitor di