Clinical and respiratory characteristics of the patients with ALS.

*<p>Defined as the presence of a hypoxic period (SpO₂<95%) for >10% of the total sleep time.</p><p>Abbreviation: ALSFRSr = Amyotrophic Lateral Sclerosis Functional Rating Scale Revised, ETCO₂ = end-tidal carbon dioxide, FVC = forced vital capacity, SpO₂ = arterial oxygen saturation measured using pulse oximetry, cluster of desaturation ≥5 desaturations (a decrease in SpO₂≥4%) within a 10-min period.</p><p>All continuous values are expressed as mean ± standard deviation.