Therapy
NIV is the mainstay of therapy for SDB in patients with NMD and has been associated with a slower decline in FVC and improved survival in some cases, as demonstrated in studies of patients with DMD or ALS. Generally, a bi-level PAP mode is preferred; the expiratory positive airway pressure prevents micro-atelectasis and improves V/Q matching and the inspiratory positive airway pressure reduces inspiratory muscle load and optimizes ventilation. As weakness progresses, patients may have difficulty creating enough negative force to initiate a spontaneous breath, thus a mode with a set respiratory rate is preferred that can be implemented in bi-level PAP or more advanced modes such as volume-assured pressure support (VAPS) modality. For patients who are unable to tolerate NIV, particularly those with severe bulbar disease and difficult to manage respiratory secretions, tracheostomy with mechanical ventilation may ultimately be needed. This decision should be made as part of a multidisciplinary shared decision-making conversation with the patient, their family, and their team of providers.
Summary
Sleep is a particularly vulnerable state for patients with NMD, and in many patients, disturbances in sleep may be the first clue to their ultimate diagnosis. It is important that sleep medicine and pulmonary specialists understand the pathophysiology and management of NMD as they can play a vital role in the interdisciplinary care of these patients.
Dr. Greer is a Sleep Medicine Fellow, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine; Dr. Collop is Professor of Medicine and Neurology, Director, Emory Sleep Center; Emory University, Atlanta, Georgia.