Sleep Hypoventilation in Patients with Neuromuscular Diseases Madeleine M. Grigg-Damberger, MD a, *, Lana K. Wagner, MD b , Lee K. Brown, MD b Increasing numbers of patients with neuromus- cular disorders (NMD) are prescribed assisted nocturnal ventilation for sleep-related chronic alveolar hypoventilation, which has resulted in im- proved health, prolonged survival, and increased quality of life for them. 1–4 Most patients with NMD who require nocturnal assisted ventilation are now first prescribed bilevel positive pressure devices, which augment spontaneous breaths and may deliver timed backup breaths when required. These devices incorporate separately adjustable inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP) bilevel positive airway pressure-sponta- neous/timed (BPAP-S/T), with EPAP promoting a patent upper airway and IPAP providing venti- lator assistance in the form of pressure sup- port (PS) (PS 5 IPAP – EPAP). 5–14 Successful nocturnal noninvasive positive pressure ventila- tion (NPPV) in NMD depends on selecting the appropriate patient, interface, ventilator, and pressure settings but also the skills of the prescribing clinician, patient motivation, and family/caregiver support. 5 Sleep specialists can diagnose and treat these patients more comfort- ably with better understanding of their disorders and special needs. The most common form of chronic sleep- disordered breathing (SDB) in patients with NMD is alveolar hypoventilation that typically first develops during rapid eye movement (REM) sleep. The diaphragm is the major muscle for inspiration awake and asleep. Patients with NMD who have significant diaphragmatic weakness depend on intercostal and accessory respiratory muscles to assist the weakened diaphragm. Because these muscles are inhibited during REM sleep, hypoven- tilation first appears during REM sleep. Weak cough reflexes, kyphoscoliosis, impaired central respiratory control, restrictive pulmonary disease, Conflicts of interest: None to declare for any of these authors. a University of New Mexico School of Medicine, MSC10 5620, One University of NM, Albuquerque, NM 87131- 0001, USA; b Division of Pulmonary, Critical Care, and Sleep Medicine, University of New Mexico School of Medicine, 1101 Medical Arts Avenue NE, Building #2, Albuquerque, NM 87102, USA * Corresponding author. E-mail address: mgriggd@salud.unm.edu KEYWORDS  Sleep hypoventilation  Neuromuscular disorders  Bilevel positive pressure ventilation  Duchenne muscular dystrophy  Amyotrophic lateral sclerosis  Myotonic dystrophy KEY POINTS  Sleep-disordered breathing, especially sleep-related hypercapnic hypoventilation, is common in patients with neuromuscular disorders (NMD).  Appropriate timing of nocturnal positive pressure ventilation (NPPV) initiation as well as manage- ment of challenges related specifically to NPPV use in NMD are essential.  A proactive approach is needed when managing the care of these patients, including close follow-up and assessment, serial monitoring of lung function, and frequent titration of their NPPV settings.  Other potential disruptors of sleep should be identified and treated, and ventilation should be maxi- mized by addressing scoliosis, malnutrition, and infections. Sleep Med Clin 7 (2012) 667–687 http://dx.doi.org/10.1016/j.jsmc.2012.09.001 1556-407X/12/$ – see front matter Ó 2012 Elsevier Inc. All rights reserved. sleep.theclinics.com