Prevalences of sleep-related breathing disorders and severity factors in chronic spinal cord injury and abled-bodied individuals undergoing rehabilitation: a comparative study.

STUDY OBJECTIVES: The objective of this study was to discern distinguishing characteristics of sleep-related breathing disorders in individuals with chronic spinal cord injury (CSCI) compared with participants without CSCI. Additionally, the study investigated factors associated with sleep-related breathing disorder severity. METHODS: This is a cross-sectional analysis of 123 individuals without CSCI, 40 tetraplegics, and 48 paraplegics who underwent attended or partially supervised full polysomnography for suspected sleep-related breathing disorders in a rehabilitation center. Polysomnographic, transcutaneous capnography, and clinical data were collected and compared between the groups. RESULTS: Among tetraplegics, apnea-hypopnea index ≥ 30 events/h (67.5%, P = .003), central apnea (17.5%, P = .007), and higher oxygen desaturation index (80.0%, P = .01) prevailed. Sleep-related hypoventilation was present in 15.4% of tetraplegics and 15.8% of paraplegics, compared with 3.2% in participants without CSCI (P = .05). In the group without CSCI and the paraplegic group, snoring and neck circumference were positively correlated with obstructive sleep apnea (OSA) severity. A positive correlation between waist circumference and OSA severity was identified in all groups, and multivariate logistic regression analysis showed that loud snoring and waist circumference had the greatest impact on OSA severity. CONCLUSIONS: Severe OSA and central sleep apnea prevailed in tetraplegic participants. Sleep-related hypoventilation was more common in tetraplegics and paraplegics than in participants without CSCI. Loud snoring and waist circumference had an impact on OSA severity in all groups. We recommend the routine implementation of transcutaneous capnography in individuals with CSCI. We underscore the significance of conducting a comprehensive sleep assessment in the rehabilitation process for individuals with CSCI. CITATION: Souza Bastos P, Amaral TLD, Yehia HC, Tavares A. Prevalences of sleep-related breathing disorders and severity factors in chronic spinal cord injury and abled-bodied individuals undergoing rehabilitation: a comparative study. J Clin Sleep Med. 2024;20(7):1119-1129.

Apnea central del sueño y respiración periódica / Central Sleep Apnea and Periodic Breathing

La apnea central del sueño es causada por una falla temporal del centro ponto-medular que es el responsable de generar una respiración rítmica. Puede ser un hallazgo fisiológico durante la transición vigilia-sueño o estar presente por múltiples causas. La enfermedad cardiovascular o cerebro-vascular, el síndrome de apneas e hipopneas obstructivas durante el sueño, el uso de opioides y el tratamiento con CPAP son las más frecuentes en la práctica clínica, mientras que en sujetos sanos las apneas centrales se relacionan con la altura durante la exposición recreacional. Este trabajo revisa la fisiopatología de las apneas centrales, su clasificación, las normas para su identificación en los estudios de sueño y un enfoque práctico sobre las opciones terapéuticas disponibles.

Central sleep apnea is caused by a temporary failure of the ponto-medullary center that is responsible for generating rhythmic breathing. It can be a physiological finding during the sleep-wake transition or be present for multiple causes. Cardiovascular or cerebrovascular disease, obstructive sleep apnea/hypopnea syndrome, use of opioids and treatment with CPAP (Continuous Positive Airway Pressure) are the most frequent in clinical practice, while in healthy subjects central apneas are related to high altitude during recreational exposure. This study reviews the physiopathology of central apneas, their classification, the current rules for their identification in sleep studies and a practical approach to the therapeutic options available.

Ondine's curse: myth meets reality.

Ondine's curse is one of the most enchanting mythical tales in the field of Medicine. The nymph Ondine was an immortal water spirit who became human after falling in love for a man, marrying him, and having a baby. In one of the versions of the tale, when she caught her husband sleeping with another woman, she cursed him to remain awake in order to control his own breathing. During the 19th century, the rare syndrome characterized by loss of autonomic breath control, while voluntary respiration remains intact, was cleverly named "Ondine's curse". Nowadays, the term Ondine's curse is usually associated with congenital central hypoventilation syndrome; however, in medical literature, it also designates several respiratory disorders. Here, we present a review of the myth focused on history, arts and medicine.

Sleep-Disordered Breathing among Newborns with Myelomeningocele.

In a matched cohort study, we report that the apnea-hypopnea index is significantly higher in neonates with myelomeningocele (34 ± 22) compared with age-matched controls (19 ± 11; P = .021). Assessment of newborns with myelomeningocele for sleep-disordered breathing may facilitate early treatment; the impact on long-term neurodevelopment is unknown.

The Impact of Altitude on Sleep-Disordered Breathing in Children Dwelling at High Altitude: A Crossover Study.

Study Objectives: Sleep-disordered breathing (SDB) is prevalent among children and is associated with adverse health outcomes. Worldwide, approximately 250 million individuals reside at altitudes higher than 2000 meters above sea level (masl). The effect of chronic high-altitude exposure on children with SDB is unknown. This study aims to determine the impact of altitude on sleep study outcomes in children with SDB dwelling at high altitude. Methods: A single-center crossover study was performed to compare results of high-altitude home polysomnography (H-PSG) with lower altitude laboratory polysomnography (L-PSG) in school-age children dwelling at high altitude with symptoms consistent with SDB. The primary outcome was apnea-hypopnea index (AHI), with secondary outcomes including obstructive AHI; central AHI; and measures of oxygenation, sleep quality, and pulse rate. Results: Twelve participants were enrolled, with 10 included in the final analysis. Median altitude was 1644 masl on L-PSG and 2531 masl on H-PSG. Median AHI was 2.40 on L-PSG and 10.95 on H-PSG. Both obstructive and central respiratory events accounted for the difference in AHI. Oxygenation and sleep fragmentation were worse and pulse rate higher on H-PSG compared to L-PSG. Conclusions: These findings reveal a clinically substantial impact of altitude on respiratory, sleep, and cardiovascular outcomes in children with SDB who dwell at high altitude. Within this population, L-PSG underestimates obstructive sleep apnea and central sleep apnea compared to H-PSG. Given the shortage of high-altitude pediatric sleep laboratories, these results suggest a role for home sleep apnea testing for children residing at high altitude.

Síndrome de Ondina, hipoventilación central congénita idiopática / Ondine´s curse or idiopathic congenital central hyperventilation syndrome

El síndrome de hipoventilación central congénito idiopático, también conocido como síndrome de Ondina, es una enfermedad poco común, caracterizada por la ausencia congénita del control central de la respiración y disfunción del sistema nervioso autónomo. Su incidencia se estima en aproximadamente 1 de cada 200 000 nacimientos al año. Es una enfermedad de transmisión autosómica dominante, derivada de una mutación heterocigótica del gen PHOX2B, presente en 90 % de los pacientes, pero su causa fisiopatológica aún no está claramente dilucidada. Presenta una elevada tasa de mortalidad, y una dependencia a la ventilación mecánica durante el sueño de por vida; sin embargo, gracias a una atención multidisciplinar y coordinada, con estrecha vigilancia y apoyo, podría esperarse que los pacientes con ella puedan llevar una vida relativamente normal. Se realiza el reporte de un caso diagnosticado en el departamento de Antioquia (Colombia), lugar con importantes barreras socioeconómicas que limitan el estudio complejo de este tipo de enfermedades de baja prevalencia global.

Idiopathic congenital central hypoventilation syndrome, also known as Ondine´s curse, is a rare disease characterized by congenital absence of the central control of breathing and autonomic nervous system dysfunction. Its incidence is estimated to be one per 200,000 births a year. It is an autosomal dominant disease derived from a heterozygous PHOX2B gene mutation, present in 90 % of patients, but its pathophysiological cause has not been elucidated yet. It has a high mortality rate and a lifelong dependency on a life-support device during sleep. However, it could be expected that a coordinated multidisciplinary care, with close monitoring and support, could help this kind of patients to have a relatively normal life. This is the report of a case diagnosed with this disease in Antioquia, Colombia, a place with significant socio-economic limitations that hinder a complete study of this type of low overall prevalence disease.

Prevalence of central sleep apnea during continous positive airway pressure (CPAP) titration in subjects with obstructive sleep apnea syndrome at an altitude of 2640 m.

BACKGROUND: The occurrence of central apneas when applying positive pressure (CPAP) to patients with obstructive sleep apnea syndrome (OSAS) is called complex sleep apnea (CompSA). This causes poor adherence to CPAP and persistence of symptoms. In Bogota, a city located at an altitude of 2640 m above sea level, chronic hypoxemia can generate certain instability of the respiratory system during sleep which could increase the presence of central apnea. The aim was to establish the prevalence of central apnea (central apnea index >5/h) in adults with moderate or severe OSAS during CPAP titration, and the factors associated with this. METHOD: Patients over 18 years old with OSAS were referred to the Fundacion Neumologica Colombiana Sleep Center, from January 2008 to June 2010. Polysomnogram (PSG) for CPAP titration was performed according to the American Academy of Sleep Medicine criteria. The prevalence was calculated and the clinical and baseline PSG factors associated with the CompSA were analyzed. RESULTS: We included 988 patients, 58% men. CompSA prevalence was 11.6%. Factors associated with CompSA were: central apneas in the baseline PSG (OR: 5.34 [3.49-8.16]), history of heart failure (OR: 2.53 [1.58-4.07]), and male sex (OR: 1.68 [1.06-2.69]). CONCLUSION: The prevalence of complex sleep apnea in Bogota (11.6%) was intermediate compared to the reported in lower altitudes. The factors associated with the development of CompSA were male sex, heart failure, and the presence of central apnea in the baseline PSG.

Treatment of sleep central apnea with non-invasive mechanical ventilation with 2 levels of positive pressure (bilevel) in a patient with myotonic dystrophy type 1.

We are reporting a case of a 29 year-old female with diagnosis of myotonic dystrophy type 1 (Steinert's disease) with excessive daytime sleepiness, muscle fatigue, snoring, frequent arousals, non-restorative sleep, and witnessed apneas. Pulmonary function tests revealed a mild decrease of forced vital capacity. Nocturnal polysomnography showed an increase of apnea/hypopnea index (85.9 events/h), mainly of central type (236), minimal oxygen saturation of 72%, and end-tidal carbon dioxide values that varied from 45 to 53 mmHg. Bi-level positive airway pressure titration was initiated at an inspiratory pressure (IPAP) of 8 and an expiratory pressure (EPAP) of 4 cm H2O. IPAP was then gradually increased to eliminate respiratory events and improve oxygen saturation. An IPAP of 12cm H20 and an EPAP of 4cm H2O eliminated all respiratory events, and the oxygen saturation remained above 90%. Bi-level positive airway pressure treatment at spontaneous/timed mode showed an improvement in snoring, apneas, and Epworth sleepiness scale decreased from 20 to 10. This case illustrates the beneficial effects of Bi-level positive airway pressure support in central sleep apnea syndrome of a patient with myotonic dystrophy type 1.

Respiración periódica y apneas del sueño centrales en pacientes con insuficiencia cardíaca: hallazgos clínicos y fisiológicos

Introducción: los trastornos respiratorios del sueño son frecuentes en la población general y en especial entre los pacientes con insuficiencia cardíaca severa. La ocurrencia de respiración periódica de Cheyne-Stokes con apneas centrales (RPCS-AC) durante el sueño, agrava el pronóstico y aumenta significativamente la mortalidad a corto plazo. El objetivo de este estudio fue determinar la prevalencia de este trastorno y las características clínico-fisiológicas de los pacientes en nuestro medio. Material y método: se estudiaron 35 pacientes con insuficiencia cardíaca, sin respiración periódica en vigilia, a los que se les realizó polisomnografía, ecocardiograma, espirometría, gasometría arterial y evaluación de los resultados funcionales del sueño. Resultados: se diagnosticó RPCS-AC en 13 pacientes (37%). Los pacientes con RPCS-AC tuvieron un sueño significativamente más fragmentado (ID/h = 32,9 ± 19,4 versus 15,8 ± 14,3, p <0,001); más tiempo en sueño superficial (S1-2 = 77,4 ± 20,1% versus 63,0 ± 16,7%, p = 0,029); menos tiempo en sueño paradojal (REM = 9,9 ± 6,3% versus 16,6 ± 9,8%, p = 0,035) y mayor tiempo en hipoxia severa durante el sueño (TA<90% = 28,4 ± 29,0% versus 2,4 ± 4,7%, p = 0,008). No existieron diferencias en la función cardíaca, el ECG, la espirometría, los gases en sangre en vigilia, ni en las repercusiones funcionales del sueño. Conclusiones: la RPCS-AC es un trastorno frecuente en la insuficiencia cardíaca avanzada que determina repercusiones adversas sobre la estructura del sueño y la oxigenación arterial.

Introduction: sleep breathing disorders are common in general population and particularly among patients with severe heart failure. The occurrence of Cheyne Stokes periodic breathing with central apneas (RPCS-AC) during sleep, worsens the prognosis and significantly increases short term mortality. The objective of this study was to determine the prevalence of this disorder and the clinic-physiological features of patients in our hospital. Methods: thirty-five consecutive patients with heart failure, without periodic respiration during wakefulness were studied with polisomnography, echocardiogram, spirometry, arterial blood gases and functional outcomes of sleep. Results: thirteen patients were diagnosed with RPCS-AC (37%). Patients with RPCS-AC had significantly more fragmented sleep (ID)/h = 32,9 ± 19,4 versus 15,8 ± 14,3, p<0,001); more time in superficial sleep (S1-2 = 77,4 ± 20,1% versus 63,0 ± 16,7%, p = 0,029); less time in paradoxical sleep (REM = 9,9 ± 6,3% versus 16,6 ± 9,8%, p = 0,035) and more time in severe hypoxia during sleep (TA<90% = 28,4 ± 29,0% versus 2,4 ± 4,7%, p = 0,008). There were no differences in cardiac function, EGG, spirometry, arterial blood gases during wakefulness, neither in sleep functional outcomes. Conclusions: RPCS-AC is a frequent disorder in advanced heart failure patients, that causes adverse consequences on sleep structure and arterial oxygenation.

Sleep apnea and REM sleep behavior disorder in patients with Chiari malformations / Apnéia do sono e distúrbio do comportamento da fase do sono com REM em pacientes com malformações de Chiari

BACKGROUND: Chiari malformations (CM) may result in the appearance of REM sleep behavior disorder (RBD) and sleep apnea syndrome (SAS) that can be considered markers of brain stem dysfunction. PURPOSE: To evaluate the frequency of RBD and SAS in patients with CM type I and II. METHOD: Were evaluated 103 patients with CM by means of full night polysomnography. Were scoring different sleep stages, frequency of abnormal movements (through video monitoring) and abnormal respiratory events. RESULTS: Of the 103 patients, 36 showed CM type I and 67 CM type II. Episodes of RBD were observed in 23 patients. Abnormal apnea-hypopnea index (AHI) was observed in 65 patients. CONCLUSION: The high rate of RBD suggests that this parassomnia and the increased frequency of central sleep apnea episodes, may be considered as a marker of progressive brain stem dysfunction.

INTRODUÇÃO: Malformações de Chiari (MC) podem gerar o aparecimento de distúrbio comportamental da fase do sono com REM (DCR) e síndrome da apnéia do sono (SAS), sugerindo a ocorrência de disfunção do tronco cerebral. OBJETIVO: Avaliar a freqüência de DCR e SAS em pacientes com MC I ou II. MÉTODO: Utilizou-se a polissonografia de noite inteira para a avaliação de 103 pacientes. Classificaram-se as diferentes fases do sono e analisou-se a freqüência de movimentos anormais (monitorada por vídeo) e de eventos respiratórios anormais. RESULTADOS: Dos 103 pacientes analisados, 36 eram portadores de MC I e 67 de MC II. Episódios de DCR foram observados em 23 pacientes. O índice de apnéia/hipopnéia foi considerado anormal em 65 pacientes. CONCLUSÃO: A alta freqüência de DCR e o aumento da freqüência de episódios de apnéia central do sono podem ser considerados manifestação de disfunção progressiva do tronco cerebral.