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Rogić Vidaković M, Šoda J, Jerković A, Benzon B, Bakrač K, Dužević S, Vujović I, Mihalj M, Pecotić R, Valić M, Mastelić A, Hagelien MV, Zmajević Schőnwald M, Đogaš Z. Obstructive Sleep Apnea Syndrome: A Preliminary Navigated Transcranial Magnetic Stimulation Study. Nat Sci Sleep 2020; 12:563-574. [PMID: 32821185 PMCID: PMC7418161 DOI: 10.2147/nss.s253281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/25/2020] [Indexed: 01/14/2023] Open
Abstract
PURPOSE An increase in resting motor threshold (RMT), prolonged cortical silent period duration (CSP), and reduced short-latency afferent inhibition (SAI), confirmed with previous transcranial magnetic stimulation (TMS), suggest decreased cortical excitability in obstructive sleep apnea syndrome (OSAS). The present study included MRI of OSAS patients for navigated TMS assessment of the RMT, as an index of the threshold for corticospinal activation at rest, and SAI as an index of cholinergic neurotransmission. We hypothesize to confirm findings on SAI and RMT with adding precision in the targeting of motor cortex in OSAS. SUBJECTS AND METHODS After acquiring head MRIs for 17 severe right-handed OSAS and 12 healthy subjects, the motor cortex was mapped with nTMS to assess the RMT and SAI, with motor evoked potentials (MEPs) recorded from the abductor-pollicis brevis (APB) muscle. The 120%RMT intensity was used for the SAI by a paired-pulse paradigm in which the electrical stimulation to the median nerve is followed by magnetic stimulation of the motor cortex at inter-stimulus intervals (ISIs) of 18-28 ms (ISIs18-28). The SAI control condition included a recording of MEPs without peripheral stimulation. Latency and amplitude of MEP at RMT at 120%RMT for eleven different at ISIs18-28 were analyzed. RESULTS The study showed a significantly lower percentage deviation of MEP amplitude at ISIs(18-28ms) from the control condition between OSAS and healthy subjects (U=44.0, p=0.01). The intensity of stimulation at RMT was significantly higher in OSAS subjects (U=55.0, p=0.04*). Correlation analysis showed that BMI significantly negatively correlated (ρ=-0.47) with MEP amplitude percentage deviation in OSAS patients. CONCLUSION The nTMS study results in increased RMT, and reduced cortical afferent inhibition in OSAS patients for SAI at ISIs18-28, confirming previous findings of impaired cortical afferent inhibition in OSAS. Future nTMS studies are desirable to elucidate the role of RMT and SAI in diagnostics and treatment of OSAS, and to elucidate the usefulness of nTMS in OSAS research.
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Affiliation(s)
- Maja Rogić Vidaković
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Joško Šoda
- University of Split, Faculty of Maritime Studies, Signal Processing, Analysis and Advanced Diagnostics Research and Education Laboratory (SPAADREL), Split, Croatia
| | - Ana Jerković
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Benjamin Benzon
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Karla Bakrač
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Silvia Dužević
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Igor Vujović
- University of Split, Faculty of Maritime Studies, Signal Processing, Analysis and Advanced Diagnostics Research and Education Laboratory (SPAADREL), Split, Croatia
| | - Mario Mihalj
- University Hospital Split, Department of Neurology, Laboratory of Electromyoneurography, Split, Croatia
| | - Renata Pecotić
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia.,University of Split, Split Sleep Medical Center, Split 21000, Croatia
| | - Maja Valić
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia.,University of Split, Split Sleep Medical Center, Split 21000, Croatia
| | - Angela Mastelić
- University of Split, School of Medicine, Department of Medical Chemistry and Biochemistry, Split, Croatia
| | - Maximilian Vincent Hagelien
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia
| | - Marina Zmajević Schőnwald
- Clinical Medical Centre "Sisters Of Mercy", Department of Neurosurgery, Clinical Unit for Intraoperative Neurophysiologic Monitoring, Zagreb, Croatia
| | - Zoran Đogaš
- University of Split, School of Medicine, Department of Neuroscience, Laboratory for Human and Experimental Neurophysiology (LAHEN), Split, Croatia.,University of Split, Split Sleep Medical Center, Split 21000, Croatia
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Zou Y, Wang W, Jin H, Nie X, Xu J, Liu Y, Kang J. The influence of 5-HT 1A receptors in the dorsal raphé nucleus on genioglossus activity. Respir Physiol Neurobiol 2017; 249:11-15. [PMID: 29208535 DOI: 10.1016/j.resp.2017.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 11/29/2022]
Abstract
Genioglossus activity maintains the patency of the upper airway. 5-HT neurons in the raphe nucleus regulate genioglossus activity. In order to study the influence of 5-HT1A receptors in dorsal raphé nucleus (DRN) on genioglossus EMG during normoxia, adult male Wistar rats were randomly divided into four groups: the artificial cerebrospinal fluid group (ACSF group), the low-concentration of 5-HT1A receptors agonist 8-OH-DPAT group (0.1 mM group), the mid-concentration 8-OH-DPAT group (0.4 mM group) and the high-concentration 8-OH-DPAT group (1.0 mM group). Rats received 0.1 μl ACSF/8-OH-DPAT microinjections into the DRN. EMG activity of the genioglossus was recorded at 5 min, 15 min and 30 min after microinjection. In three 8-OH-DPAT groups, genioglossus EMG activity significantly decreased at 5 min after microinjection and persisted for 30 min. The significantly decreased EMG activity was more pronounced in the mid- and high-concentration groups than in the low-concentration group, indicating that 5-HT1A receptors in the DRN could rapidly and continuously inhibit genioglossus EMG activity during normoxia.
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Affiliation(s)
- Ying Zou
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
| | - Wei Wang
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China.
| | - Hongyu Jin
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
| | - Xinshi Nie
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
| | - Jiahuan Xu
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
| | - Ying Liu
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
| | - Jian Kang
- Institute of Respiratory Disease, The First Hospital of China Medical University, Shenyang City, China
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Supratrigeminal Bilaterally Projecting Neurons Maintain Basal Tone and Enable Bilateral Phasic Activation of Jaw-Closing Muscles. J Neurosci 2017; 36:7663-75. [PMID: 27445144 DOI: 10.1523/jneurosci.0839-16.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 06/07/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Anatomical studies have identified brainstem neurons that project bilaterally to left and right oromotor pools, which could potentially mediate bilateral muscle coordination. We use retrograde lentiviruses combined with a split-intein-mediated split-Cre-recombinase system in mice to isolate, characterize, and manipulate a population of neurons projecting to both the left and right jaw-closing trigeminal motoneurons. We find that these bilaterally projecting premotor neurons (BPNs) reside primarily in the supratrigeminal nucleus (SupV) and the parvicellular and intermediate reticular regions dorsal to the facial motor nucleus. These BPNs also project to multiple midbrain and brainstem targets implicated in orofacial sensorimotor control, and consist of a mix of glutamatergic, GABAergic, and glycinergic neurons, which can drive both excitatory and inhibitory inputs to trigeminal motoneurons when optogenetically activated in slice. Silencing BPNs with tetanus toxin light chain (TeNT) increases bilateral masseter activation during chewing, an effect driven by the expression of TeNT in SupV BPNs. Acute unilateral optogenetic inhibition of SupV BPNs identifies a group of tonically active neurons that function to lower masseter muscle tone, whereas unilateral optogenetic activation of SupV BPNs is sufficient to induce bilateral masseter activation both during resting state and during chewing. These results provide evidence for SupV BPNs in tonically modulating jaw-closing muscle tone and in mediating bilateral jaw closing. SIGNIFICANCE STATEMENT We developed a method that combines retrograde lentiviruses with the split-intein-split-Cre system in mice to isolate, characterize, and manipulate neurons that project to both left and right jaw-closing motoneurons. We show that these bilaterally projecting premotor neurons (BPNs) reside primarily in the supratrigeminal nucleus and the rostral parvicellular and intermediate reticular nuclei. BPNs consist of both excitatory and inhibitory populations, and also project to multiple brainstem nuclei implicated in orofacial sensorimotor control. Manipulation of the supratrigeminal BPNs during natural jaw-closing behavior reveals a dual role for these neurons in eliciting phasic muscle activation and in maintaining basal muscle tone. The retrograde lentivirus carrying the split-intein-split-Cre system can be applied to study any neurons with bifurcating axons innervating two brain regions.
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Akhter S, Abeyratne UR. Detection of REM/NREM snores in obstructive sleep apnoea patients using a machine learning technique. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/5/055022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lipford MC, Ramar K, Liang YJ, Lin CW, Chao YT, An J, Chiu CH, Tsai YJ, Shu CH, Lee FP, Chiang RPY. Serotnin as a possible biomarker in obstructive sleep apnea. Sleep Med Rev 2016; 28:125-32. [DOI: 10.1016/j.smrv.2015.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 08/07/2015] [Accepted: 08/07/2015] [Indexed: 01/21/2023]
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Shin W, Jen R, Li Y, Malhotra A. Tailored treatment strategies for obstructive sleep apnea. Respir Investig 2015; 54:2-7. [PMID: 26718138 DOI: 10.1016/j.resinv.2015.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/07/2015] [Accepted: 09/22/2015] [Indexed: 01/28/2023]
Abstract
Obstructive sleep apnea (OSA) is characterized by repetitive collapse of the upper airway (UA) during sleep and is associated with chronic intermittent hypoxemia, catecholamine surges, and sleep disrupt. Multiple pathophysiological risk factors have been identified and contribute to OSA, including anatomical abnormalities (elevated UA mechanical load), compromised UA dilators, increased loop gain (unstable respiratory control), and decreased arousal threshold. These factors may contribute to the pathophysiology of sleep apnea in different individuals and recent evidence suggests that treatment may be targeted towards underlying pathophysiological mechanism. In some cases, combination therapy may be required to treat the condition.
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Affiliation(s)
- Wonchul Shin
- Department of Neurology, Kyung Hee University College of Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea.
| | - Rachel Jen
- Respiratory Division, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Yanru Li
- Beijing Tongren Hospital, Capital Medical University, Department of Otolaryngology Head and Neck Surgery, Beijing, China.
| | - Atul Malhotra
- University of California at San Diego, Division of Pulmonary, Critical Care and Sleep Medicine, 9300 Campus Point Drive #7381, La Jolla, CA 92037-7381, USA.
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Boentert M, Brenscheidt I, Glatz C, Young P. Effects of non-invasive ventilation on objective sleep and nocturnal respiration in patients with amyotrophic lateral sclerosis. J Neurol 2015; 262:2073-82. [PMID: 26076745 DOI: 10.1007/s00415-015-7822-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 12/14/2022]
Abstract
In amyotrophic lateral sclerosis (ALS), non-invasive ventilation (NIV) is indicated if sleep-disordered breathing (SDB), daytime hypercapnia, or significant diaphragmatic weakness is present. We investigated both short-term and long-term effects of NIV on objective measures of sleep and nocturnal respiration in patients with ALS. Polysomnography (PSG) and transcutaneous capnography were conducted for diagnosis of SDB (T0), for treatment initiation (T1), and follow-up 3, 9, and 15 months later (T2, T3, and T4, respectively). Records from 65 patients were retrospectively analyzed at T0 and T1. At subsequent timepoints, the number of full data sets decreased since follow-up sleep studies frequently included polygraphy rather than PSG (T2, 38 patients, T3, 17 patients, T4, 11 patients). At T0, mean age was 63.2 years, 29 patients were female, and 22 patients had bulbar ALS. Immediate sequelae of NIV initiation included significant increases of slow wave sleep, rapid eye movement sleep, and oxygen saturation. Mean apnea-hypopnea index, respiratory rate, and the maximum transcutaneous carbon dioxide tension were reduced. At T2-T4, normoxia and normocapnia were preserved. Sleep quality measures showed no alteration as diurnal use of NIV gradually increased reflecting disease progression. In contrast to previous reports, improvement of sleep and respiratory outcomes was found in both non-bulbar and bulbar patients. NIV significantly improves objective sleep quality and SDB in the first night of treatment in patients with bulbar and non-bulbar ALS. NIV warrants nocturnal normoventilation without deterioration of sleep quality in the long run with only minor changes to ventilator settings.
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Affiliation(s)
- Matthias Boentert
- Department of Sleep Medicine and Neuromuscular Disorders, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149, Münster, Germany.
| | - Inga Brenscheidt
- Department of Sleep Medicine and Neuromuscular Disorders, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149, Münster, Germany
| | - Christian Glatz
- Department of Sleep Medicine and Neuromuscular Disorders, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149, Münster, Germany
| | - Peter Young
- Department of Sleep Medicine and Neuromuscular Disorders, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149, Münster, Germany
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Sutherland K, Cistulli PA. Recent advances in obstructive sleep apnea pathophysiology and treatment. Sleep Biol Rhythms 2014. [DOI: 10.1111/sbr.12098] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Kate Sutherland
- Department of Respiratory and Sleep Medicine; Center for Sleep Health and Research; Royal North Shore Hospital; University of Sydney; Sydney New South Wales Australia
- Discipline of Sleep Medicine; Sydney Medical School; University of Sydney; Sydney New South Wales Australia
- Woolcock Institute of Medical Research; University of Sydney; Sydney New South Wales Australia
| | - Peter A Cistulli
- Department of Respiratory and Sleep Medicine; Center for Sleep Health and Research; Royal North Shore Hospital; University of Sydney; Sydney New South Wales Australia
- Discipline of Sleep Medicine; Sydney Medical School; University of Sydney; Sydney New South Wales Australia
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Edge D, McDonald FB, Jones JFX, Bradford A, O'Halloran KD. Effect of chronic intermittent hypoxia on the reflex recruitment of the genioglossus during airway obstruction in the anesthetized rat. PROGRESS IN BRAIN RESEARCH 2014; 209:147-68. [PMID: 24746047 DOI: 10.1016/b978-0-444-63274-6.00008-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We sought to test the hypothesis that chronic intermittent hypoxia (CIH)-a feature of sleep-disordered breathing in humans-impairs reflex recruitment of the genioglossus (GG, pharyngeal dilator) during obstructive airway events. Adult male Wistar rats were exposed to 20 cycles of normoxia and hypoxia (5% O2 at nadir) per hour, 8h a day for 7 days (CIH, N=7). The sham group (N=7) were exposed to normoxia in parallel. Following gas treatments, rats were anesthetized with an i.p. injection of urethane (1.5g/kg; 20%, w/v). Fine concentric needle electrodes were inserted into the GG and the costal diaphragm. Discriminated GG motor unit potentials and whole electromyograph (EMG), together with arterial blood pressure and arterial O2 saturation, were recorded during quiet basal breathing and during nasal airway occlusion. Airway occlusion significantly increased GG EMG activity in all animals; but there was no difference in the reflex response to airway occlusion between sham and CIH-treated animals (+105±22% vs. +105±17%, mean±SEM for area under the curve of integrated GG EMG, % increase from baseline, p=0.99). Occluded breaths were characterized by a significant increase in the firing frequency of phasically active units and the recruitment of large motor units that were quiescent under basal conditions. Though there are reports of impaired control of the upper airway following CIH in the rat, we conclude that reflexly evoked motor discharge to the GG is not affected by 7 days of CIH, a paradigm that we have shown increases apnea index in sleeping rats.
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Affiliation(s)
- Deirdre Edge
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
| | - Fiona B McDonald
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - James F X Jones
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Aidan Bradford
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Ken D O'Halloran
- Department of Physiology, Western Gateway Building, University College Cork, Cork, Ireland
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Strohl KP, Butler JP, Malhotra A. Mechanical properties of the upper airway. Compr Physiol 2013; 2:1853-72. [PMID: 23723026 DOI: 10.1002/cphy.c110053] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions.
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Affiliation(s)
- Kingman P Strohl
- Center for Sleep Disorders Research, Division of Pulmonary, Critical Care, and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
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Fregosi RF, Ludlow CL. Activation of upper airway muscles during breathing and swallowing. J Appl Physiol (1985) 2013; 116:291-301. [PMID: 24092695 DOI: 10.1152/japplphysiol.00670.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The upper airway is a complex muscular tube that is used by the respiratory and digestive systems. The upper airway is invested with several small and anatomically peculiar muscles. The muscle fiber orientations and their nervous innervation are both extremely complex, and how the activity of the muscles is initiated and adjusted during complex behaviors is poorly understood. The bulk of the evidence suggests that the entire assembly of tongue and laryngeal muscles operate together but differently during breathing and swallowing, like a ballet rather than a solo performance. Here we review the functional anatomy of the tongue and laryngeal muscles, and their neural innervation. We also consider how muscular activity is altered as respiratory drive changes, and briefly address upper airway muscle control during swallowing.
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Affiliation(s)
- Ralph F Fregosi
- Department of Physiology, University of Arizona, Tucson, Arizona
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Fuller DD, Lee KZ, Tester NJ. The impact of spinal cord injury on breathing during sleep. Respir Physiol Neurobiol 2013; 188:344-54. [PMID: 23791824 DOI: 10.1016/j.resp.2013.06.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 01/07/2023]
Abstract
The prevalence of sleep disordered breathing (SDB) following spinal cord injury (SCI) is considerably greater than in the general population. While the literature on this topic is still relatively small, and in some cases contradictory, a few general conclusions can be drawn. First, while both central and obstructive sleep apnea (OSA) has been reported after SCI, OSA appears to be more common. Second, SDB after SCI likely reflects a complex interplay between multiple factors including body mass, lung volume, autonomic function, sleep position, and respiratory neuroplasticity. It is not yet possible to pinpoint a "primary factor" which will predispose an individual with SCI to SDB, and the underlying mechanisms may change during progression from acute to chronic injury. Given the prevalence and potential health implications of SDB in the SCI population, we suggest that additional studies aimed at defining the underlying mechanisms are warranted.
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Affiliation(s)
- David D Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States; McKnight Brain Institute, University of Florida, Gainesville, FL 32610, United States.
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Ramirez JM, Garcia AJ, Anderson TM, Koschnitzky JE, Peng YJ, Kumar GK, Prabhakar NR. Central and peripheral factors contributing to obstructive sleep apneas. Respir Physiol Neurobiol 2013; 189:344-53. [PMID: 23770311 DOI: 10.1016/j.resp.2013.06.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/03/2013] [Accepted: 06/05/2013] [Indexed: 11/30/2022]
Abstract
Apnea, the cessation of breathing, is a common physiological and pathophysiological phenomenon. Among the different forms of apnea, obstructive sleep apnea (OSA) is clinically the most prominent manifestation. OSA is characterized by repetitive airway occlusions that are typically associated with peripheral airway obstructions. However, it would be an oversimplification to conclude that OSA is caused by peripheral obstructions. OSA is the result of a dynamic interplay between chemo- and mechanosensory reflexes, neuromodulation, behavioral state and the differential activation of the central respiratory network and its motor outputs. This interplay has numerous neuronal and cardiovascular consequences that are initially adaptive but in the long-term become major contributors to morbidity and mortality. Not only OSA, but also central apneas (CA) have multiple, and partly overlapping mechanisms. In OSA and CA the underlying mechanisms are neither "exclusively peripheral" nor "exclusively central" in origin. This review discusses the complex interplay of peripheral and central nervous components that characterizes the cessation of breathing.
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Affiliation(s)
- Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Department of Neurological Surgery and Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.
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Sahin-Yilmaz A, Naclerio RM. Anatomy and physiology of the upper airway. PROCEEDINGS OF THE AMERICAN THORACIC SOCIETY 2011; 8:31-39. [PMID: 21364219 DOI: 10.1016/b978-1-4160-6645-3.00101-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The nose is the major portal of air exchange between the internal and external environment. The nose participates in the vital functions of conditioning inspired air toward a temperature of 37°C and 100% relative humidity, providing local defense and filtering inhaled particulate matter and gases. It also functions in olfaction, which provides both a defense and pleasure for the individual. Understanding normal physiology provides the basis for recognizing abnormalities.
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Affiliation(s)
- Asli Sahin-Yilmaz
- Umraniye Education and Research Hospital, Department of Otolaryngology, Istanbul, Turkey
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Biomechanics of the upper airway: Changing concepts in the pathogenesis of obstructive sleep apnea. Int J Oral Maxillofac Surg 2010; 39:1149-59. [DOI: 10.1016/j.ijom.2010.09.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2010] [Accepted: 09/13/2010] [Indexed: 11/19/2022]
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Abstract
Obstructive sleep apnea (OSA) results from complex interactions between anatomy and physiology. A structurally small and abnormally collapsible upper airway predisposes to disease, and interacts with normal and pathologic physiologic mechanisms to determine severity of disease. Understanding the pathophysiology provides insight into airway collapse, and may improve treatment and lead to potential new medical and surgical treatments for OSA.
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Affiliation(s)
- B Tucker Woodson
- Division of Sleep Medicine, Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin at Froedtert West, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA.
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Abstract
Obstructive sleep apnea (OSA) is a highly significant condition based both on the high prevalence in community and significant consequences. Obstructive sleep apnea syndrome (OSAS), OSA together with hypersomnolence, is seen in 4% of middle-aged men and 2% of middle-aged women. OSA is associated with impaired quality of life and increased risks of motor vehicle accidents, cardiovascular disease (including hypertension and coronary artery disease), and metabolic syndrome. There is some evidence for the use of conservative interventions such as weight loss and position modification. CPAP remains the mainstay of treatment in this condition with high-level evidence supporting its efficacy. Continuous positive airway pressure (CPAP) is an intrusive therapy, with long-term adherence rates of less than 70%. Dental appliances have been shown to be effective therapy in some subjects but are limited by the inability to predict treatment responders. Alternative treatments are discussed but there is little role for upper airway surgery (except in a select few experienced institutions) or pharmacological treatment. The current levels of evidence for the different treatment regimens are reviewed.
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Affiliation(s)
- Craig A Hukins
- Sleep Disorders Centre, Department of Respiratory and Sleep Medicine, Princess Alexandra Hospital, Woolloongabba, Australia.
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Abstract
Considerable progress has been made over the last several decades in our understanding of the pathophysiology of both central and obstructive sleep apnea. Central sleep apnea, in its various forms, is generally the product of an unstable ventilatory control system (high loop gain) with increased controller gain (high hypercapnic responsiveness) generally being the cause. High plant gain can contribute under certain circumstances (hypercapnic patients). On the other hand, obstructive sleep apnea can develop as the result of a variety of physiologic characteristics. The combinations of these may vary considerably between patients. Most obstructive apnea patients have an anatomically small upper airway with augmented pharyngeal dilator muscle activation maintaining airway patency awake, but not asleep. However, individual variability in several phenotypic characteristics may ultimately determine who develops apnea and how severe the apnea will be. These include: (1) upper airway anatomy, (2) the ability of upper airway dilator muscles to respond to rising intrapharyngeal negative pressure and increasing Co(2) during sleep, (3) arousal threshold in response to respiratory stimulation, and (4) loop gain (ventilatory control instability). As a result, patients may respond to different therapeutic approaches based on the predominant abnormality leading to the sleep-disordered breathing.
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Affiliation(s)
- David P White
- Brigham and Women's Hospital Division of Sleep Medicine, Sleep Research at BI, 75 Francis Street, Boston, MA 02115, USA.
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Tamisier R, Wuyam B, Nicolle I, Pépin JL, Orliaguet O, Perrin CP, Lévy P. Awake flow limitation with negative expiratory pressure in sleep disordered breathing. Sleep Med 2005; 6:205-13. [PMID: 15854850 DOI: 10.1016/j.sleep.2004.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 10/20/2004] [Accepted: 10/21/2004] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND PURPOSE Although upper airway collapsibility (UAC) is theoretically useful to anticipate severity of sleep-disordered breathing (SDB), inspiratory UAC measurements are poorly correlated with obstructive sleep apnea (OSA) severity. PATIENTS AND METHODS We investigated in 15 healthy and 35 SDB awake subjects whether negative expiratory pressure (NEP) could be a technique which would allow us to anticipate SDB severity. We characterized in these subjects, both in supine and sitting position, at -5 and -10 cm H(2)O, the flow-volume curves and a new NEP quantitative index (ratio of the 'areas under the curve' of NEP flow-volume loop vs. spontaneous flow-volume loop). RESULTS Abnormal flow-volume curves were significantly more frequent in patients with SDB than in healthy subjects, for both negative pressures in sitting posture and -10 cm H(2)O in supine position. The quantitative index decreased with the severity of SDB, independently of confounding factors (age, body mass index (BMI) and expiratory reserve volume (ERV)). In the supine position, at -5 and -10 cm H(2)O, thresholds of less than 160 and 180% respectively identified in 96.6% of SDB, whereas thresholds of greater than 160 and 180% were adequately classified in 76.9% of controls. CONCLUSIONS NEP flow-volume curves and quantitative index during wakefulness are useful methods to detect UAC. These results, however, should be confirmed by a prospective study in the general population.
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Affiliation(s)
- R Tamisier
- Service de Pneumologie, CHU Nice, France.
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Malhotra A, Trinder J, Fogel R, Stanchina M, Patel SR, Schory K, Kleverlaan D, White DP. Postural effects on pharyngeal protective reflex mechanisms. Sleep 2004; 27:1105-12. [PMID: 15532204 PMCID: PMC3504469 DOI: 10.1093/sleep/27.6.1105] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
STUDY OBJECTIVES Pharyngeal muscle dilators are important in obstructive sleep apnea pathogenesis because the failure of protective reflexes involving these muscles yields pharyngeal collapse. Conflicting results exist in the literature regarding the responsiveness of these muscles during stable non-rapid eye movement sleep. However, variations in posture in previous studies may have influenced these findings. We hypothesized that tongue protruder muscles are maximally responsive to negative pressure pulses during supine sleep, when posterior tongue displacement yields pharyngeal occlusion. DESIGN We studied all subjects in the supine and lateral postures during wakefulness and stable non-rapid eye movement sleep by measuring genioglossus and tensor palatini electromyograms during basal breathing and following negative pressure pulses. SETTING Upper-airway physiology laboratory of Sleep Medicine Division, Brigham and Women's Hospital. SUBJECTS/PARTICIPANTS 17 normal subjects. MEASUREMENTS AND RESULTS We observed an increase in genioglossal responsiveness to negative pressure pulses in sleep as compared to wakefulness in supine subjects (3.9 percentage of maximum [%max] +/- 1.1 vs 4.4 %max +/- 1.0) but a decrease in the lateral decubitus position (4.1 %max +/- 1.0 vs 1.5 %max +/- 0.4), the interaction effect being significant. Despite this augmented reflex, collapsibility, as measured during negative pressure pulses, increased more while subjects were in the supine position as compared with the lateral decubitus position. While the interaction between wake-sleep state and position was also significant for the tensor palatini, the effect was weaker than for genioglossus, although, for tensor palatini, baseline activity was markedly reduced during non-rapid eye movement sleep as compared with wakefulness. CONCLUSION We conclude that body posture does have an important impact on genioglossal responsiveness to negative pressure pulses during non-rapid eye movement sleep. We speculate that this mechanism works to prevent pharyngeal occlusion when the upper airway is most vulnerable to collapse eg, during supine sleep.
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Affiliation(s)
- Atul Malhotra
- Sleep Medicine and Pulmonary/Critical Care Divisions, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Civardi C, Naldi P, Cantello R. Cortico-motoneurone excitability in patients with obstructive sleep apnoea. J Sleep Res 2004; 13:159-63. [PMID: 15175096 DOI: 10.1111/j.1365-2869.2004.00391.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A disordered neuromotor control of pharynx muscles may play a role in the genesis of obstructive sleep apnoea syndrome (OSAS). This raises the possibility of a dysfunction of projections descending from the cortex to segmental nuclei. With single pulse transcranial magnetic stimulation (TMS) we studied the physiology of the corticospinal projection to hand muscles in seven OSAS patients. At first, we compared them with nine age- and sex-matched normal controls in the wake state. The only abnormality was a lengthening of the central silent period (P < 0.001). This supports a steady imbalance of motor cortical interneurone activities towards a state of enhanced inhibition. Then we looked at changes of the motor-evoked potential (MEP) size and latency, according to whether patients were awake, or in a non-rapid eye movement (REM) 2 sleep stage, or during a typical apnoea. During non-REM 2 sleep, the average MEP amplitude was significantly (P < 0.05) smaller than in the awake state. The MEP latency was, in turn, significantly longer (P < 0.05). During apnoeas, the MEP size decreased, and the latency increased further (P < 0.05), indicating an extra depression of the cortico-motoneuronal activity. All TMS changes were detected outside the pharyngeal district, suggesting a widespread dysfunction of the cortico-motoneuronal system in the OSAS, which is more evident during apnoeas.
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Affiliation(s)
- Carlo Civardi
- Section of Neurology, Department of Medical Sciences, Università del Piemonte Orientale A. Avogadro, Novara, Italy
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Veasey SC. Serotonin agonists and antagonists in obstructive sleep apnea: therapeutic potential. ACTA ACUST UNITED AC 2004; 2:21-9. [PMID: 14720019 DOI: 10.1007/bf03256636] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Obstructive sleep apnea hypopnea syndrome (OSAHS) is a prevalent disorder associated with substantial cardiovascular and neurobehavioral morbidity. Yet this is a disorder for which there are no widely effective pharmacotherapies. The pathophysiology of obstructive sleep apnea namely, normal respiration in waking with disordered breathing only in sleep, suggests that this disorder should be readily amenable to drug therapy. Over the past 10 years, we have gained tremendous insight into the neurochemical mechanisms involved in state-dependent control of respiration. It is apparent from this work that there are many potential avenues for pharmacotherapies, including several seemingly conflicting directions for serotonergic therapies. Serotonin delivery is reduced to upper airway dilator motor neurons in sleep, and this contributes, at least in part, to sleep-related reductions in dilator muscle activity and upper airway obstruction. The dilator motor neuron post-synaptic serotonin receptors are 5-HT(2A) and 5-HT(2C) subtypes, and in adults the presynaptic 5-HT receptor in motor nuclei is 5-HT(1B), an inhibitory receptor. Serotonin receptors are also found within central respiratory neuronal groups, and these receptor subtypes include 5-HT(1A) (inhibitory) and 5-HT(2) receptors. Peripherally, stimulation of 5-HT(2A), 5-HT(2C) and 5-HT(3) receptor subtypes have an inhibitory effect on respiration via action at the nodose ganglion. Many of these receptor subtypes and their signal transduction pathways may be affected by oxidative stress in obstructive sleep apnea. These alterations will make finding drug therapies for sleep apnea more challenging, but not insurmountable. Future directions are suggested for elucidating safe, well-tolerated serotonergic drugs for this disorder. Tryptophan was one of the first serotonergic drugs tested for OSAHS. This drug was withdrawn from the market as a result of reports linking tryptophan use with eosinophilic myalgia syndrome and life-threatening pulmonary hypertension. Newer drugs with serotonergic activity tested in persons with sleep-disordered breathing include buspirone, fluoxetine and paroxetine. Trials are presently being conducted to evaluate the effects of 5-HT(2A) and 5-HT(3) antagonists on OSAHS. Many of the drugs tested have not shown significant improvement in sleep apnea. However, with continued effort to elucidate the pharmacology of neurochemical control of state-dependent changes in respiratory control, the availability of pharmacological therapy for this disorder is not too far away.
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Affiliation(s)
- Sigrid C Veasey
- Department of Medicine, Center for Sleep and Respiratory Neurobiology, University of Pennsylvania, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4283, USA.
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Hedner J, Kraiczi H, Peker Y, Murphy P. Reduction of sleep-disordered breathing after physostigmine. Am J Respir Crit Care Med 2003; 168:1246-51. [PMID: 12958052 DOI: 10.1164/rccm.200211-1344oc] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The cholinesterase inhibitor physostigmine (PHYS) was investigated in a double-blind, placebo-controlled, randomized, crossover trial of 10 male patients with moderate to severe obstructive sleep apnea. PHYS (0.12 microg/minute/kg, 7-hour infusion) reduced mean apnea/hypopnea index (AHI) by 13.6 (95% confidence interval [CI], 2.2-25.1) corresponding to 21.4% (95% CI, -5.5 to 47.9) and increased minimum SaO2 by 8.7% (95% CI, -0.3 to 17.7) corresponding to 23.2% (95% CI, 4.8-41.3). During the last third of the night, coinciding with predicted plasma concentration steady state, non-REM sleep AHI decreased by 19.2 (95% CI, 0.1-38.3) or 14.9% (95% CI, -43.6 to 77.7) and REM AHI by 33.8 (95% CI, 13.7-54.0) or 67.5% (95% CI, 49.7-85.3). Mean total sleep time was reduced by 74 minutes (95% CI, 33.9-114.9), but patients with the least pronounced sleep shortening had the largest reduction of AHI (r = 0.73, p < 0.02). The nocturnal decline in heart rate was reduced by PHYS. Moreover, resting (early-night placebo heart rate) was positively correlated with proportional reduction of REM apnea index (r = 0.69, p < 0.02). Body mass index was negatively correlated with reduction of REM AHI (r = 0.77, p < 0.02). This, predominantly REM-related, reduction of obstructive sleep apnea after PHYS may provide a new treatment option if the effects are maintained in long-term studies.
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Affiliation(s)
- Jan Hedner
- Sleep Laboratory, Department of Pulmonary Medicine and Allergology, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden.
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25
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Martial FP, Dunleavy M, Jones JFX, Nolan P, O'Regan RG, McNicholas W, Bradford A. Activity of Dorsal Medullary Respiratory Neurons in Awake Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 536:445-53. [PMID: 14635698 DOI: 10.1007/978-1-4419-9280-2_56] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Affiliation(s)
- F P Martial
- Department of Physiology, Royal College of Surgeons in Ireland, Ireland
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Abstract
Obstructive sleep apnea is a prevalent disorder associated with significant neurobehavioral and cardiovascular morbidities. At present, however, there are no widely effective, well-tolerated pharmacotherapies for obstructive sleep apnea. The pathogenesis of this disorder predicts that sleep apnea should respond to drug therapies. Specifically, respiration during waking in persons with sleep apnea is normal, while collapse of the upper airway occurs exclusively in sleep. This state-dependency in upper airway patency suggests state-dependent changes in neurochemical control of the upper airway dilator motoneurons, and this, in turn, suggests that appropriate medications would maintain upper airway dilator function in sleep and prevent sleep related collapse of the upper airway. The past few years have brought significant insight into the neural mechanisms governing upper airway dilator muscle function. This article provides updates on neurochemical mechanisms, emphasizing a role for serotonergic control, and reviews recent drug therapy trials for sleep apnea. We are currently well poised to develop effective pharmacotherapies for obstructive sleep apnea, with opportunities to target several regions involved in respiratory control.
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Affiliation(s)
- S C Veasey
- Division of Sleep Medicine and Pulmonary, Department of Medicine, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104-4283, USA.
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Feroah TR, Forster HV, Pan L, Schlick NE, Martino P, Rice T. Negative pressure effects on mechanically opposing pharyngeal muscles in awake and sleeping goats. J Appl Physiol (1985) 2001; 91:2289-97. [PMID: 11641373 DOI: 10.1152/jappl.2001.91.5.2289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our aim was to investigate the effects of the negative pressure reflex on mechanically opposing pharyngeal muscles during wakefulness, slow-wave sleep (SWS), and rapid eye movement (REM) sleep. In four goats with isolated upper airways, we measured tracheal airflow and electrical activity of the thyropharyngeus (TP; constricting), the stylopharyngeus (SP; dilating), and the diaphragm (Dia). In the wakefulness state in response to negative pressure tests, TP decreased (65%), SP increased (198%), and tidal volume (VT) (66%) and rate of rise of Dia (Dia(slope), 69%) decreased (P < 0.02). Similarly, during SWS, the negative pressure response of TP (31%), VT (61%), and Dia(slope) (60%) decreased, whereas SP (113%) increased, relative to SWS control (P < 0.02). In REM sleep, the negative pressure response by TP and SP were small, whereas both VT (38%) and Dia(slope) (24%) were greatly decreased (P < 0.02) compared with REM control. Inspiratory duration remained unchanged in response to negative pressure tests in all states. These data provide evidence that mechanically opposing inspiratory and expiratory pharyngeal muscles are reciprocally controlled and their response to negative pressure are state dependent.
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Affiliation(s)
- T R Feroah
- Department of Physiology, Medical College of Wisconsin and Zablocki Veterans Affairs, Milwaukee 53226, USA
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Jelev A, Sood S, Liu H, Nolan P, Horner RL. Microdialysis perfusion of 5-HT into hypoglossal motor nucleus differentially modulates genioglossus activity across natural sleep-wake states in rats. J Physiol 2001; 532:467-81. [PMID: 11306665 PMCID: PMC2278543 DOI: 10.1111/j.1469-7793.2001.0467f.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
1. Serotonin (5-hydroxytryptamine, 5-HT) excites hypoglossal (XII) motoneurons in reduced preparations, and it has been suggested that withdrawal of 5-HT may underlie reduced genioglossus (GG) muscle activity in sleep. However, systemic administration of 5-HT agents in humans has limited effects on GG activity. Whether 5-HT applied directly to the XII motor nucleus increases GG activity in an intact preparation either awake or asleep has not been tested. 2. The aim of this study was to develop a novel freely behaving animal model for in vivo microdialysis of the XII motor nucleus across sleep-wake states, and test the hypothesis that 5-HT application will increase GG activity. 3. Eighteen rats were implanted with electroencephalogram and neck muscle electrodes to record sleep-wake states, and GG and diaphragm electrodes for respiratory muscle recording. Microdialysis probes were implanted into the XII motor nucleus and perfused with artificial cerebrospinal fluid (ACSF) or 10 mM 5-HT. 4. Normal decreases in GG activity occurred from wakefulness to non-rapid eye movement (non-REM) and REM sleep with ACSF (P < 0.01). Compared to ACSF, 5-HT caused marked GG activation across all sleep-wake states (increases of 91-251 %, P < 0.015). Importantly, 5-HT increased sleeping GG activity to normal waking levels for as long as 5-HT was applied (3-5 h). Despite tonic stimulation by 5-HT, periods of phasic GG suppression and excitation occurred in REM sleep compared with non-REM. 5. The results show that sleep-wake states differentially modulate GG responses to 5-HT at the XII motor nucleus. This animal model using in vivo microdialysis of the caudal medulla will enable the determination of neural mechanisms underlying pharyngeal motor control in natural sleep.
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Affiliation(s)
- A Jelev
- Departments of Medicine and Physiology, University of Toronto, Toronto, Canada, M5S 1A8
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