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Sleep-disordered breathing in neuromuscular disease
Sleep-disordered breathing (SDB) is a common sleep disturbance in neuromuscular disease (NMD) affecting 36% to 53% of diagnosed adults (Arens R, et al. Paediatr Respir Rev. 2010;11[1]:24). Disturbances in sleep may serve as the earliest sign of muscle weakness in these patients, at times being detected before their underlying neuromuscular disease is diagnosed. This is of paramount importance to sleep medicine and pulmonary physicians who may be among the first specialists to evaluate these patients and can play a vital role in the recognition and diagnosis of neuromuscular disease. Herein, we will provide a guide to aid the reader in recognizing the early signs and symptoms of NMD as it pertains to sleep, as earlier diagnosis may lead to improved quality of life or possibly even survival, in some cases.
Pathophysiology
To begin, it is important to understand the pathophysiology of NMD and how it is altered during the sleep state. Sleep-related physiologic changes in healthy humans include reduction in upper airway muscle tone, blunting of chemoreceptors associated with pharyngeal dilator augmentation, and sleep stage-specific changes in skeletal muscle tone. In patients with NMD, these changes may not be adequately compensated for, leading to sleep-disordered breathing that can present as sleep apnea, hypoventilation, or hypoxia (Govindarajan R, et al. Sleep Issues in Neuromuscular Disorders: A Clinical Guide. Springer International Publishing AG, Springer Nature 2018).
Central respiratory control
The respiratory centers in the pons and medulla are generally spared from the primary effects of most NMD; however, over time, they may be affected secondarily. Similar to obesity hypoventilation syndrome (OHS), untreated chronic sleep-related hypoventilation from NMD can impair the sensitivity of respiratory chemoreceptors leading to worsening hypoventilation.
Upper airway resistance
Pharyngeal muscle tone is key to maintaining a patent airway during sleep. In some NMD, bulbar muscle weakness with pharyngeal dilator muscle hypotonia leads to increased upper airway resistance, especially during REM sleep, which can result in obstructive sleep apnea (OSA). In addition to weakness affecting the upper airway musculature, anatomical changes may also contribute to sleep-disordered breathing. In Pompe disease, for example, macroglossia and fibro-fatty replacement of tongue muscles may occur, leading to the development of OSA.
Diaphragm weakness
In NMD that affects the diaphragm, there is an increased reliance on the skeletal muscles of respiration to maintain adequate ventilation as the underlying disease progresses. Generally, weakness of the diaphragm will cause disturbances in REM sleep first as, during REM, ventilation predominately depends on the diaphragm and patients lose the assistance of their skeletal muscles. However, over time, the progressive weakening of the diaphragm will progress to involve NREM sleep as well, clinically manifesting with frank sleep apnea, hypoventilation, and, ultimately, chronic hypercapnic respiratory failure.
Inspiratory muscle weakness
As noted above, there are many other muscles used in inspiration in addition to the diaphragm. Other primary muscles include the intercostal and scalene muscles, and accessory muscles include the sternocleidomastoid, pectoralis, latissimus dorsi, erector spinae, and trapezius muscles. While sleep and breathing problems may begin early in the course of a neuromuscular disease, the complex restrictive lung disease pattern that we see in these patients may not develop until the respiratory muscles of the chest wall are involved. This restriction, which corresponds to lower lung volumes, leads to a fall in the caudal traction force of the airways which can lead to reduction in the pharyngeal airway cross section. Because these issues are worsened in the supine position, their pathophysiologic effects on respiration are most notable during sleep, putting patients at higher risk of OSA.
Cardiac abnormalities
Lastly, it should be noted that diseases such as the muscular dystrophies, myotonic dystrophy, mitochondriopathies, and nemaline myopathy can be associated with a cardiomyopathy ,which can lead to central sleep apnea in the form of Cheyne-Stokes breathing.
Sleep-disordered breathing in specific NMDs
In amyotrophic lateral sclerosis (ALS), up to 75% of patients may have SDB, the majority of which is central sleep apnea (CSA) and hypoventilation although they still have a higher prevalence of obstructive sleep apnea (OSA) than the general population. Whether the diaphragm or the pharyngeal muscles are predominantly affected may have something to do with the type of apnea a patient experiences; however, studies have shown that even in bulbar ALS, CSA is most common. It should be noted, that this is not Cheyne-Stokes CSA, but rather lack of chest wall and abdominal movement due to weakness. (David WS, et al. J Neurol Sci. 1997;152[suppl 1]:S29-35).
In myasthenia gravis (MG), about 40% to 60% of patients have SDB, and about 30% develop overt respiratory weakness, generally late in the course of their disease. Many of these patients report excessive daytime sleepiness, often attributed to myasthenic fatigue requiring treatment with corticosteroids. It is important to evaluate for sleep apnea, given that if diagnosed and treated, their generalized fatigue may improve and the need for steroids may be reduced or eliminated altogether. It is also important to note that the respiratory and sleep issues MG patients face may not correlate with the severity of their overall disease, such that patients well-controlled on medications from a generalized weakness standpoint may still require home noninvasive ventilation (NIV) for chronic respiratory failure due to weakness of the respiratory system muscles.
Duchenne muscular dystrophy (DMD), an X-linked disease associated with dysfunction of dystrophin synthesis, is often diagnosed in early childhood and gradually progresses over years. Their initial sleep and respiratory symptoms can be subtle and may start with increased nighttime awakenings and daytime somnolence. Generally, these patients will develop OSA in the first decade of life and progress to hypoventilation in their second decade and beyond. These patients are especially important to recognize, as studies have shown appropriate NIV therapy may significantly prolong their life (Finder JD, et al; American Thoracic Society. Am J Respir Crit Care Med. 2004(Aug 15);170[4]:456-465).
In addition to the well-known motor neuron and neuromuscular diseases mentioned above, neuropathic diseases can lead to sleep disturbances, as well. In Charcot-Marie-Tooth (CMT), pharyngeal and laryngeal neuropathy, as well as hypoglossal nerve dysfunction, lead to OSA. Similar to ALS and MG, there is a significant amount of CSA and hypoventilation, likely related to phrenic neuropathy. In contrast to MG, in CMT, the severity of neuropathic disease does correlate to the severity of sleep apnea.
Testing
Testing can range from overnight oximetry to polysomnogram (PSG) with CO2 monitoring. Generally, all patients with a rapidly progressive neuromuscular disease should get pulmonary function testing (PFT) (upright and supine) to evaluate forced vital capacity (FVC) every 3 to 6 months to monitor for respiratory failure. Laboratory studies that can be helpful in assessing for SDB are the PaCO2 (> 45 mm Hg) measured on an arterial blood gas and serum bicarbonate levels (>27 mmol/L or a base excess >4 mmol/L). Patients can qualify for NIV with an overnight SaO2 less than or equal to 88% for greater than or equal to 5 minutes in a 2-hour recording period, PaCO2 greater than or equal to 45 mm Hg, forced vital capacity (FVC) < 50% of predicted, or maximal inspiratory pressure (MIP) <60 cm H2O. For ALS specifically, sniff nasal pressure < 40 cm H2O and orthopnea are additional criteria that can be used. It is worth noting that a PSG is not required for NIV qualification in neuromuscular respiratory insufficiency. However, PSG is beneficial in patients with preserved PFTs but suspected of having early nocturnal respiratory impairment.
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.
Sleep-disordered breathing (SDB) is a common sleep disturbance in neuromuscular disease (NMD) affecting 36% to 53% of diagnosed adults (Arens R, et al. Paediatr Respir Rev. 2010;11[1]:24). Disturbances in sleep may serve as the earliest sign of muscle weakness in these patients, at times being detected before their underlying neuromuscular disease is diagnosed. This is of paramount importance to sleep medicine and pulmonary physicians who may be among the first specialists to evaluate these patients and can play a vital role in the recognition and diagnosis of neuromuscular disease. Herein, we will provide a guide to aid the reader in recognizing the early signs and symptoms of NMD as it pertains to sleep, as earlier diagnosis may lead to improved quality of life or possibly even survival, in some cases.
Pathophysiology
To begin, it is important to understand the pathophysiology of NMD and how it is altered during the sleep state. Sleep-related physiologic changes in healthy humans include reduction in upper airway muscle tone, blunting of chemoreceptors associated with pharyngeal dilator augmentation, and sleep stage-specific changes in skeletal muscle tone. In patients with NMD, these changes may not be adequately compensated for, leading to sleep-disordered breathing that can present as sleep apnea, hypoventilation, or hypoxia (Govindarajan R, et al. Sleep Issues in Neuromuscular Disorders: A Clinical Guide. Springer International Publishing AG, Springer Nature 2018).
Central respiratory control
The respiratory centers in the pons and medulla are generally spared from the primary effects of most NMD; however, over time, they may be affected secondarily. Similar to obesity hypoventilation syndrome (OHS), untreated chronic sleep-related hypoventilation from NMD can impair the sensitivity of respiratory chemoreceptors leading to worsening hypoventilation.
Upper airway resistance
Pharyngeal muscle tone is key to maintaining a patent airway during sleep. In some NMD, bulbar muscle weakness with pharyngeal dilator muscle hypotonia leads to increased upper airway resistance, especially during REM sleep, which can result in obstructive sleep apnea (OSA). In addition to weakness affecting the upper airway musculature, anatomical changes may also contribute to sleep-disordered breathing. In Pompe disease, for example, macroglossia and fibro-fatty replacement of tongue muscles may occur, leading to the development of OSA.
Diaphragm weakness
In NMD that affects the diaphragm, there is an increased reliance on the skeletal muscles of respiration to maintain adequate ventilation as the underlying disease progresses. Generally, weakness of the diaphragm will cause disturbances in REM sleep first as, during REM, ventilation predominately depends on the diaphragm and patients lose the assistance of their skeletal muscles. However, over time, the progressive weakening of the diaphragm will progress to involve NREM sleep as well, clinically manifesting with frank sleep apnea, hypoventilation, and, ultimately, chronic hypercapnic respiratory failure.
Inspiratory muscle weakness
As noted above, there are many other muscles used in inspiration in addition to the diaphragm. Other primary muscles include the intercostal and scalene muscles, and accessory muscles include the sternocleidomastoid, pectoralis, latissimus dorsi, erector spinae, and trapezius muscles. While sleep and breathing problems may begin early in the course of a neuromuscular disease, the complex restrictive lung disease pattern that we see in these patients may not develop until the respiratory muscles of the chest wall are involved. This restriction, which corresponds to lower lung volumes, leads to a fall in the caudal traction force of the airways which can lead to reduction in the pharyngeal airway cross section. Because these issues are worsened in the supine position, their pathophysiologic effects on respiration are most notable during sleep, putting patients at higher risk of OSA.
Cardiac abnormalities
Lastly, it should be noted that diseases such as the muscular dystrophies, myotonic dystrophy, mitochondriopathies, and nemaline myopathy can be associated with a cardiomyopathy ,which can lead to central sleep apnea in the form of Cheyne-Stokes breathing.
Sleep-disordered breathing in specific NMDs
In amyotrophic lateral sclerosis (ALS), up to 75% of patients may have SDB, the majority of which is central sleep apnea (CSA) and hypoventilation although they still have a higher prevalence of obstructive sleep apnea (OSA) than the general population. Whether the diaphragm or the pharyngeal muscles are predominantly affected may have something to do with the type of apnea a patient experiences; however, studies have shown that even in bulbar ALS, CSA is most common. It should be noted, that this is not Cheyne-Stokes CSA, but rather lack of chest wall and abdominal movement due to weakness. (David WS, et al. J Neurol Sci. 1997;152[suppl 1]:S29-35).
In myasthenia gravis (MG), about 40% to 60% of patients have SDB, and about 30% develop overt respiratory weakness, generally late in the course of their disease. Many of these patients report excessive daytime sleepiness, often attributed to myasthenic fatigue requiring treatment with corticosteroids. It is important to evaluate for sleep apnea, given that if diagnosed and treated, their generalized fatigue may improve and the need for steroids may be reduced or eliminated altogether. It is also important to note that the respiratory and sleep issues MG patients face may not correlate with the severity of their overall disease, such that patients well-controlled on medications from a generalized weakness standpoint may still require home noninvasive ventilation (NIV) for chronic respiratory failure due to weakness of the respiratory system muscles.
Duchenne muscular dystrophy (DMD), an X-linked disease associated with dysfunction of dystrophin synthesis, is often diagnosed in early childhood and gradually progresses over years. Their initial sleep and respiratory symptoms can be subtle and may start with increased nighttime awakenings and daytime somnolence. Generally, these patients will develop OSA in the first decade of life and progress to hypoventilation in their second decade and beyond. These patients are especially important to recognize, as studies have shown appropriate NIV therapy may significantly prolong their life (Finder JD, et al; American Thoracic Society. Am J Respir Crit Care Med. 2004(Aug 15);170[4]:456-465).
In addition to the well-known motor neuron and neuromuscular diseases mentioned above, neuropathic diseases can lead to sleep disturbances, as well. In Charcot-Marie-Tooth (CMT), pharyngeal and laryngeal neuropathy, as well as hypoglossal nerve dysfunction, lead to OSA. Similar to ALS and MG, there is a significant amount of CSA and hypoventilation, likely related to phrenic neuropathy. In contrast to MG, in CMT, the severity of neuropathic disease does correlate to the severity of sleep apnea.
Testing
Testing can range from overnight oximetry to polysomnogram (PSG) with CO2 monitoring. Generally, all patients with a rapidly progressive neuromuscular disease should get pulmonary function testing (PFT) (upright and supine) to evaluate forced vital capacity (FVC) every 3 to 6 months to monitor for respiratory failure. Laboratory studies that can be helpful in assessing for SDB are the PaCO2 (> 45 mm Hg) measured on an arterial blood gas and serum bicarbonate levels (>27 mmol/L or a base excess >4 mmol/L). Patients can qualify for NIV with an overnight SaO2 less than or equal to 88% for greater than or equal to 5 minutes in a 2-hour recording period, PaCO2 greater than or equal to 45 mm Hg, forced vital capacity (FVC) < 50% of predicted, or maximal inspiratory pressure (MIP) <60 cm H2O. For ALS specifically, sniff nasal pressure < 40 cm H2O and orthopnea are additional criteria that can be used. It is worth noting that a PSG is not required for NIV qualification in neuromuscular respiratory insufficiency. However, PSG is beneficial in patients with preserved PFTs but suspected of having early nocturnal respiratory impairment.
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.
Sleep-disordered breathing (SDB) is a common sleep disturbance in neuromuscular disease (NMD) affecting 36% to 53% of diagnosed adults (Arens R, et al. Paediatr Respir Rev. 2010;11[1]:24). Disturbances in sleep may serve as the earliest sign of muscle weakness in these patients, at times being detected before their underlying neuromuscular disease is diagnosed. This is of paramount importance to sleep medicine and pulmonary physicians who may be among the first specialists to evaluate these patients and can play a vital role in the recognition and diagnosis of neuromuscular disease. Herein, we will provide a guide to aid the reader in recognizing the early signs and symptoms of NMD as it pertains to sleep, as earlier diagnosis may lead to improved quality of life or possibly even survival, in some cases.
Pathophysiology
To begin, it is important to understand the pathophysiology of NMD and how it is altered during the sleep state. Sleep-related physiologic changes in healthy humans include reduction in upper airway muscle tone, blunting of chemoreceptors associated with pharyngeal dilator augmentation, and sleep stage-specific changes in skeletal muscle tone. In patients with NMD, these changes may not be adequately compensated for, leading to sleep-disordered breathing that can present as sleep apnea, hypoventilation, or hypoxia (Govindarajan R, et al. Sleep Issues in Neuromuscular Disorders: A Clinical Guide. Springer International Publishing AG, Springer Nature 2018).
Central respiratory control
The respiratory centers in the pons and medulla are generally spared from the primary effects of most NMD; however, over time, they may be affected secondarily. Similar to obesity hypoventilation syndrome (OHS), untreated chronic sleep-related hypoventilation from NMD can impair the sensitivity of respiratory chemoreceptors leading to worsening hypoventilation.
Upper airway resistance
Pharyngeal muscle tone is key to maintaining a patent airway during sleep. In some NMD, bulbar muscle weakness with pharyngeal dilator muscle hypotonia leads to increased upper airway resistance, especially during REM sleep, which can result in obstructive sleep apnea (OSA). In addition to weakness affecting the upper airway musculature, anatomical changes may also contribute to sleep-disordered breathing. In Pompe disease, for example, macroglossia and fibro-fatty replacement of tongue muscles may occur, leading to the development of OSA.
Diaphragm weakness
In NMD that affects the diaphragm, there is an increased reliance on the skeletal muscles of respiration to maintain adequate ventilation as the underlying disease progresses. Generally, weakness of the diaphragm will cause disturbances in REM sleep first as, during REM, ventilation predominately depends on the diaphragm and patients lose the assistance of their skeletal muscles. However, over time, the progressive weakening of the diaphragm will progress to involve NREM sleep as well, clinically manifesting with frank sleep apnea, hypoventilation, and, ultimately, chronic hypercapnic respiratory failure.
Inspiratory muscle weakness
As noted above, there are many other muscles used in inspiration in addition to the diaphragm. Other primary muscles include the intercostal and scalene muscles, and accessory muscles include the sternocleidomastoid, pectoralis, latissimus dorsi, erector spinae, and trapezius muscles. While sleep and breathing problems may begin early in the course of a neuromuscular disease, the complex restrictive lung disease pattern that we see in these patients may not develop until the respiratory muscles of the chest wall are involved. This restriction, which corresponds to lower lung volumes, leads to a fall in the caudal traction force of the airways which can lead to reduction in the pharyngeal airway cross section. Because these issues are worsened in the supine position, their pathophysiologic effects on respiration are most notable during sleep, putting patients at higher risk of OSA.
Cardiac abnormalities
Lastly, it should be noted that diseases such as the muscular dystrophies, myotonic dystrophy, mitochondriopathies, and nemaline myopathy can be associated with a cardiomyopathy ,which can lead to central sleep apnea in the form of Cheyne-Stokes breathing.
Sleep-disordered breathing in specific NMDs
In amyotrophic lateral sclerosis (ALS), up to 75% of patients may have SDB, the majority of which is central sleep apnea (CSA) and hypoventilation although they still have a higher prevalence of obstructive sleep apnea (OSA) than the general population. Whether the diaphragm or the pharyngeal muscles are predominantly affected may have something to do with the type of apnea a patient experiences; however, studies have shown that even in bulbar ALS, CSA is most common. It should be noted, that this is not Cheyne-Stokes CSA, but rather lack of chest wall and abdominal movement due to weakness. (David WS, et al. J Neurol Sci. 1997;152[suppl 1]:S29-35).
In myasthenia gravis (MG), about 40% to 60% of patients have SDB, and about 30% develop overt respiratory weakness, generally late in the course of their disease. Many of these patients report excessive daytime sleepiness, often attributed to myasthenic fatigue requiring treatment with corticosteroids. It is important to evaluate for sleep apnea, given that if diagnosed and treated, their generalized fatigue may improve and the need for steroids may be reduced or eliminated altogether. It is also important to note that the respiratory and sleep issues MG patients face may not correlate with the severity of their overall disease, such that patients well-controlled on medications from a generalized weakness standpoint may still require home noninvasive ventilation (NIV) for chronic respiratory failure due to weakness of the respiratory system muscles.
Duchenne muscular dystrophy (DMD), an X-linked disease associated with dysfunction of dystrophin synthesis, is often diagnosed in early childhood and gradually progresses over years. Their initial sleep and respiratory symptoms can be subtle and may start with increased nighttime awakenings and daytime somnolence. Generally, these patients will develop OSA in the first decade of life and progress to hypoventilation in their second decade and beyond. These patients are especially important to recognize, as studies have shown appropriate NIV therapy may significantly prolong their life (Finder JD, et al; American Thoracic Society. Am J Respir Crit Care Med. 2004(Aug 15);170[4]:456-465).
In addition to the well-known motor neuron and neuromuscular diseases mentioned above, neuropathic diseases can lead to sleep disturbances, as well. In Charcot-Marie-Tooth (CMT), pharyngeal and laryngeal neuropathy, as well as hypoglossal nerve dysfunction, lead to OSA. Similar to ALS and MG, there is a significant amount of CSA and hypoventilation, likely related to phrenic neuropathy. In contrast to MG, in CMT, the severity of neuropathic disease does correlate to the severity of sleep apnea.
Testing
Testing can range from overnight oximetry to polysomnogram (PSG) with CO2 monitoring. Generally, all patients with a rapidly progressive neuromuscular disease should get pulmonary function testing (PFT) (upright and supine) to evaluate forced vital capacity (FVC) every 3 to 6 months to monitor for respiratory failure. Laboratory studies that can be helpful in assessing for SDB are the PaCO2 (> 45 mm Hg) measured on an arterial blood gas and serum bicarbonate levels (>27 mmol/L or a base excess >4 mmol/L). Patients can qualify for NIV with an overnight SaO2 less than or equal to 88% for greater than or equal to 5 minutes in a 2-hour recording period, PaCO2 greater than or equal to 45 mm Hg, forced vital capacity (FVC) < 50% of predicted, or maximal inspiratory pressure (MIP) <60 cm H2O. For ALS specifically, sniff nasal pressure < 40 cm H2O and orthopnea are additional criteria that can be used. It is worth noting that a PSG is not required for NIV qualification in neuromuscular respiratory insufficiency. However, PSG is beneficial in patients with preserved PFTs but suspected of having early nocturnal respiratory impairment.
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.