A Clinical Trial of Early Ventilation in Amyotrophic Lateral Sclerosis (EVENT ALS)

Inclusion Criteria: * Diagnosed with ALS using the Gold Coast Criteria within the last 6 months * Age ≥18 years * Willingness and ability to participate in study procedures * Provision of signed and dated informed consent form Exclusion Criteria: 1. Current or prior or recommended/prescribed use of NIV including: i) bi-level positive pressure ventilation, such as a respiratory assist device or home ventilator ii) Current or prior use of continuous positive airway pressure, or "CPAP" therapy 2. Forced vital capacity \<50% of predicted normal 3. Maximal inspiratory pressure \> -60 cmH2O (eg, -50 or -40 cmH2O would be excluded) 4. Chronic use of supplemental oxygen at any part of the day 5. Enrollment in hospice 6. Current tracheostomy 7. Prior history of sleep apnea where non-invasive ventilation was used or recommended 8. Thoracic, abdominal, facial or ophthalmic surgery in the prior 6 weeks 9. Coughing up blood 10. Myocardial infarction in the previous 4 weeks 11. Absolute contraindication to NIV, which includes lethargy, obtundation, facial fractures, active pneumothorax, and airway obstruction (such as a tumor) 12. Presence of cognitive dysfunction that would impair ability to complete study procedures, as determined by neurology attending physician