Idiopathic Central Sleep Apnea Research Articles

Change in sleep quality Induced by adaptive servo-ventilation for central sleep apnea: 6-month follow-up of the multicenter nationwide French FACIL-VAA cohort.

A large number of symptomatic individuals with central sleep apnea (CSA) in clinical practice have an indication for adaptive servo-ventilation (ASV) therapy. What are the effects of ASV therapy on sleep quality and PROMs in patients with CSA across a range of devices and indications. This prospective, multicenter, observational cohort study was conducted in France and enrolled participants from June 2017 to February 2020. Adults with predominant CSA at diagnosis or obstructive sleep apnea with central events not controlled with continuous positive airway pressure who had an indication for ASV were eligible. Participants attended clinic visits at baseline, and after 1, 3, 6 and 12 months of follow-up. The primary endpoint was the change in Pittsburgh Sleep Quality Index (PSQI) score from baseline to 6-month follow-up (evaluated using a Wilcoxon signed rank test on paired data). We included 526 individuals (median age 69 years, 88.2% male). The indication for ASV included CSA with cardiovascular/neurologic etiology (38.4%), treatment-emergent CSA (36.1%), idiopathic CSA (14.1%) or drug-induced CSA (11.4%). At 6-month follow-up, study participants were using ASV for a median of 6.1 h/night. The median [interquartile range] change in the PSQI score from baseline to 6 months in the overall study population was -1 [-3; 0] (p<0.001), with significant results across all indications for ASV except for drug-induced CSA, where the median change was similar to the overall result but did not achieve statistical significance (-1 [-2; 1]; p=0.0866). Overall, 65% of participants had a ≥1-point improvement in the PSQI. Individuals with a clinical indication for ASV therapy experienced improved sleep quality during real-world treatment, irrespective of which ASV device was used.

Idiopathic central sleep apnea with periodicity presenting as Cheyne-Stokes breathing – Case report

Cheyne-Stokes breathing (CSB) is described by a cyclic variation in breathing with periods of central apneas or hypopneas alternating with periods of hypopneas in a gradual waxing and waning manner. It is usually seen in patients with congestive cardiac failure or neurologic disorders. We describe this rare case of idiopathic central sleep apnea coming in a periodic fashion presenting as CSB pattern without specific causes. Overnight polysomnography test showed central sleep apnea; but cardiac evaluation and magnetic resonance imaging of the brain could not find any cause of this sleep-disordered breathing. Idiopathic central sleep apnea usually presents with poor quality of sleep, but many of them easily misdiagnosed and do not get any proper treatment.

Unexplained Significant Central Sleep Apnea in Infants: Clinical Presentation and Outcomes.

Unexplained significant central sleep apnea in term infants presents as central apneas with associated oxygen desaturations requiring respiratory support and monitoring for prolonged periods. However, there is a paucity of literature describing idiopathic central sleep apnea (ICSA) in term or near-term infants. Our aim was to describe the clinical manifestations, polysomnography data, interventions, and trajectory of ICSA in infants. This is a retrospective study of infants (gestational age ≥ 35weeks) who presented with significant central apneas and were subsequently diagnosed with ICSA following polysomnography and clinical investigations between January 2011 and April 2021 at a tertiary care hospital in Canada. Polysomnography data, clinical investigations, and treatments were documented. Eighteen infants (male, 78%; median gestational age 38weeks) with ICSA were included. Initial polysomnograms were completed at a median (interquartile range [IQR]) age of 1.2 (0.6-1.6) months (n = 18) and follow-up polysomnograms at 12.4 (10.6-14.0) months (n = 13). Compared to baseline diagnostic polysomnograms, at follow-up there was a significant reduction in the median (IQR) central apnea-hypopnea index (26.1 [18.2-52.9] versus 4.2[2.6-7.2] events/hour; p = 0.001), desaturation index (30.9 [12.2-57.4] versus 3.9[3.0-7.9] events/hour; p = 0.002), average transcutaneous carbon dioxide (41.9 [40.1-47.3 versus 39.4[37.5-42.7] mmHg; p = 0.025), and improved nadir oxygen saturation (79.8 [69.1-83.0] versus 85.5[83.2-87.8]%; p = 0.033), respectively. Prescribed treatments included supplemental oxygen (14/18, 78%), caffeine (5/18, 28%), and noninvasive ventilation (1/18, 6%). Infants with significant unexplained ICSA have a favorable clinical trajectory over time. Further research is needed to understand the etiology of this rare disorder.

P-SP003. Idiopathic central sleep apnea with periodicity presenting as cheyne-stokes breathing

Introduction . Cheyne-Stokes breathing (CSB) is described by a cyclic variation in breathing with periods of central apneas or hypopneas alternating with periods of hyperpneas in a gradual waxing and waning manner. We describe this rare case of idiopathic central sleep apnea coming in a periodic fashion presenting as CSB pattern without specific causes. Results . A 72-year-old male (body mass index: 21.9 kg/m 2 ) with the complaints of excessive daytime sleepiness and fatigue for about 2 years. On detailed sleep history patient denied snoring, cataplexy, hypnogogic hallucination, sleep paralysis and sleep attack. No neurological deficit was seen in clinical evaluation. ENT evaluation was normal. Cardiac evaluation showed artrial fibrillation with no cardiac failure. An overnight Polysomnography (PSG) test showed total sleep time of 443 minutes, sleep latency of 19.0 min, and sleep efficiency of 70.0%. Sleep architecture for stage 1 sleep was 31.7%, stage 2 sleep was 52.4%, slow wave sleep was 12.9%, REM sleep was 3.1%. Total arousal index was 21.8/hr. Mean SaO2 was 96.4%, the lowest SaO2 was 82.8%, and SaO2 below 90% was 0.1%. Snoring was not observed and periodic limb movement index was 8.8/hr. PSG also showed cyclic fluctuation in breathing with periods of central apneas; alternating with periods of hyperpneas in a gradual waxing and waning fashion; but cardiac evaluation and magnetic resonance imaging of the brain could not find any cause of this sleep-disordered breathing. Conclusion . The pathogenesis and etiology of CSA is still vague. We think that further studies and follow up will be required to determine whether idiopathic central sleep apnea presenting as CSB pattern is the initial indication of certain diseases. So we concluded that this case was an idiopathic central sleep apnea with periodicity; presenting as CSB pattern.

842 PAP Therapy in a Pandemic: Management of Severe Mixed Apnea Predominant OSA &amp; CSA during the COVID-19 Pandemic

IntroductionIntroduction/Background: A new protocol and standard of care was created amidst the COVID-19 Pandemic that began in 2020. Traditional split night studies fell out of favor and were replaced by solely diagnostic studies with placement on Auto-PAP therapy if treatment of sleep disordered breathing was required. Some patients, however, required a more tailored approach if diagnostic polysomnogram (PSG) was particularly concerning. Our case report describes the treatment of a patient with severe Mixed Apnea Predominant Obstructive Sleep Apnea (OSA) with accompanying Central Sleep Apnea (CSA) using COVID-19 Precautions.Report of case(s)Case Description: A 48 year old AAM patient with a PMH of HTN, pre-diabetes, GERD, obesity and tobacco abuse initially presented to Sleep Medicine in late January 2020 with complaints of snoring, witnessed apneas, waking up gasping, excessive daytime sleepiness, fatigue, and non-restorative sleep for many years with ESS 24 and FSS 48 on initial evaluation. Diagnostic PSG showed AHI 76.9 with O2 desaturation to 59% and demonstrated the presence of severe Mixed Apnea predominant OSA and CSA with worsening during REM sleep. Because of the severity, he underwent a PAP titration in August 2020 using the AASM COVID-19 sleep study precautions which included use of a negative pressure room. Optimal control of snoring, apneic respiratory events and oxygen desaturations was achieved at 14 cm H2O in the supine body position during REM sleep. Follow up with Sleep Medicine in October and December 2020 showed objective compliance over a 30 day period not completely at goal due to issues with mask desensitization and sleep hygiene, however the patient subjectively reported that he noticed great improvement in snoring, excessive daytime sleepiness and fatigue.Conclusion: Discussion/ConclusionWith a diagnosis of Severe Mixed Apnea Predominant OSA as well as CSA noted during the study, the differential diagnosis included CHF, Chiari malformation, opioid abuse and idiopathic CSA as the cause. Despite a dangerous pandemic, appropriate therapy for certain patients must still be attained. Special protocols developed during the COVID-19 Pandemic allowed for our patient to receive adequate treatment, while ensuring the safety of all involved.Support (if any)References COVID 19: FAQs for Sleep Clinicians. AASM official website. https://aasm.org/covid-19-resources/covid-19-faq/

The influence of opioids and nonopioid central nervous system active medications on central sleep apnea: a case-control study.

Opioids are known to contribute to central sleep apnea (CSA), but the influence of nonopioid central nervous system active medications (CNSAMs) on CSA remains unclear. In light of the hypothesized impact of nonopioid CNSAMs on respiration, we examined the relationships between the use of opioids only, nonopioid CNSAMs alone, and their combination with CSA. Among all adults who underwent polysomnography testing at the University of Michigan's sleep laboratory between 2013 and 2018 (n = 10,606), we identified 212 CSA cases and randomly selected 300 controls. Participants were classified into four groups based on their medication use: opioids alone, nonopioid CNSAMs only, their combination, and a reference group, including those who did not use any of these medications. We defined CSA as a binary outcome and as a continuous variable using central apnea index data. Logistic and linear regression were used to examine associations between medication use, CSA diagnosis, and central apnea index. Study participants included 58% men, and mean age was 50 (± 14 standard deviation years. Nearly half of the study participants did not use opioids or nonopioid CNSAMs, 6% used opioids alone, 27% nonopioid CNSAMs alone, and 16% used a combination of these medications. In adjusted analyses, opioids-only users had a nearly twofold increase in CSA odds, whereas those who used a combination of opioids and nonopioid CNSAMs had fivefold higher odds of CSA relative to the reference group. In contrast, the use of nonopioid CNSAMs alone had protective associations with CSA. This report showed increased odds of CSA, particularly among patients with sleep complaints who were prescribed opioids in combination with nonopioid CNSAMs compared with those who did not use any of these medications.

Transvenous phrenic nerve stimulation to treat idiopathic central sleep apnea.

Idiopathic central sleep apnea (ICSA) is a rare disorder diagnosed when known causes of central sleep apnea are excluded. No established treatments exist for ICSA, and long-term studies are lacking. We assessed the long-term effectiveness and safety of transvenous phrenic nerve stimulation in patients with ICSA. In the remedē System Pivotal Trial, 16/151 (11%) participants with central sleep apnea were diagnosed as having ICSA. Patients were implanted and followed through 18 months of active therapy. Polysomnograms obtained at baseline and at 6, 12, and 18 months were scored by a central laboratory. Sleep metrics and patient-reported quality of life outcomes were assessed. Patients experienced moderate-severe central sleep apnea. The baseline AHI, central apnea index, and arousal index were 40, 25, and 32 events/h of sleep, respectively. These metrics improved at 6, 12, and 18 months of therapy: the AHI decreased by 25, 25, and 23 events/h (P < .001 at each visit), the central apnea index by 22, 23, and 22 events/h (P < .001 at each visit), and the arousal index by 12 (P = .005), 11 (P = .035), and 13 events/h (P < .001). Quality of life instruments showed clinically meaningful improvements in daytime somnolence, fatigue, general and mental health, and social functioning. The only related serious adverse event was lead component failure in 1 patient. This is the longest prospective study for the treatment of ICSA. Transvenous phrenic nerve stimulation significantly decreased sleep-disordered breathing metrics with consequent improvement in quality of life at 6 months, and all benefits were sustained through 18 months. Registry: ClinicalTrials.gov; Name: Respicardia, Inc. Pivotal Trial of the remedē System; URL: https://clinicaltrials.gov/ct2/show/NCT01816776; Identifier: NCT01816776.

Surgical complication of undiagnosed idiopathic central sleep apnea: case report

Surgical complication of undiagnosed idiopathic central sleep apnea: case report

1023 Resolution of Idiopathic Central Sleep Apnea after Prolonged Treatment with Acetazolamide: A Case Report

1023 Resolution of Idiopathic Central Sleep Apnea after Prolonged Treatment with Acetazolamide: A Case Report

Sleep Complaints and Sleep Architecture in Children With Idiopathic Central Sleep Apnea.

Idiopathic central sleep apnea (ICSA) is categorized as a type of nonhypercapnic central sleep apnea (CSA). Recurrent cessation and resumption of respiration leads to sleep fragmentation, which causes excessive daytime sleepiness, frequent nocturnal awakenings, or both. ICSA has been described in the adult population but there is limited information in children. The purpose of this study was to describe clinical manifestations and polysomnographic findings in children with ICSA. A retrospective review of medical records and polysomnograms was performed for 14 pediatric patients with ICSA, 9 from Cincinnati Children's Hospital Medical Center and 5 from Antwerp University Hospital. Polysomnographic features of patients with ICSA were compared with those of nine age-matched control group subjects. Patients with CSA caused by medical or neurological disorders, medication use, or substance use were excluded. Sleep complaints were common in the 14 children with ICSA, including those with sleep-onset insomnia (7 children), frequent nighttime awakening (3 children), restless sleep (7 children), and daytime sleepiness (5 children). Symptoms of sleep-disordered breathing were noted in 11 of 14 subjects. Compared to that of the control group, sleep latency in the ICSA group was significantly prolonged (P < .05). The percentage of stage 2 sleep was significantly higher (P < .05), and slow wave sleep was significantly lower in patients with ICSA (P < .05). Similar to adult patients, children with ICSA present with complaints of insomnia, daytime sleepiness, and symptoms of obstructive sleep apnea. Analysis of polysomnograms reveals prolonged sleep latency, increased stage 2 sleep, and decreased slow wave sleep. Further studies are needed to assess mechanisms and the role of hypercapnic response in the pathogenesis of children with ICSA.

Heart rate acceleration runs and deceleration runs in patients with obstructive sleep apnea syndrome.

This study aimed to explore the patterns of heart rate acceleration runs and deceleration runs in patients with obstructive sleep apnea syndrome and to investigate the influence of apnea events on this pattern. The 6-h electrocardiography results of patients who were referred for overnight polysomnography were retrospectively analyzed. The frequencies of heart rate acceleration runs and deceleration runs of different lengths were calculated for each patient and compared among patients with obstructive sleep apnea syndrome of varying degrees of severity, between patients with obstructive sleep apnea on and off continuous positive airway pressure, and between two matched groups of patients with idiopathic central sleep apnea and obstructive sleep apnea. A total of 231 patients were enrolled. Patients with severe obstructive sleep apnea exhibited significantly increased frequencies of long acceleration and deceleration runs after multivariate adjustment, while no significant differences were observed in the frequencies of short runs. Thirty-nine obstructive sleep apnea patients who were treated with continuous positive airway pressure showed a significant decrease in the frequency of long deceleration runs and a decreasing trend in the frequency of long acceleration runs. Patients with idiopathic pure central sleep apnea exhibited no significant changes in the frequencies of acceleration and deceleration runs after they were placed on continuous positive airway pressure. The distributions of heart rate acceleration and deceleration runs are related to the severity of obstructive sleep apnea. Long runs are more closely related to obstructive respiratory events, while short runs do not appear to be related to these events.

Idiopathic central sleep apnea during REM sleep

Idiopathic central sleep apnea during rapid eye movement (REM) sleep is an extremely rare condition and only two cases have been reported so far. We present the case of a male patient who presented with chronic insomnia. Blood gas analysis during wakefulness suggested the presence of hypocapnia. Polysomnographic examination revealed central sleep apnea occurring predominantly during REM sleep. The patient responded well to continuous positive airway pressure (CPAP) at a pressure of 6 cmH2O as well as to acetazolamide therapy.

Positive airway pressure therapy in patients with opioid-related central sleep apnea

This study aims to compare treatment response and adherence rate to positive airway pressure (PAP) in patients with opioid-related central sleep apnea (O-CSA) and idiopathic central sleep apnea (I-CSA). We performed a retrospective chart over a 5-year period performed at a VA sleep center. Continuous PAP (CPAP) was prescribed initially for all participants. For those nonresponders (apnea hypopnea index (AHI) of >10/h), bi-level PAP (BiPAP) or adaptive servoventilation (ASV) was instituted upon provider's discretion. Adherence to therapy was checked with the built-in meter. Thirty-four patients with O-CSA and 61 with I-CSA were included in the analysis. The two groups were comparable with respect to age, body mass index (BMI), Epworth Sleepiness Scale, and burden of comorbidities. The mean daily equivalent dose of morphine in the O-CSA was 168 mg (range 30-1,217 mg). In the O-CSA group, 24% of PAP-naïve patients responded to CPAP compared to 38% in the I-CSA group. BiPAP and ASV were comparable in eliminating central events in both O-CSA (66 versus 60 %) and I-CSA (93 versus 90%), respectively. Eight patients (24%) with O-CSA and six patients (10%) with I-CSA were considered nonresponders. The adherence rate was 48 and 24% in the I-CSA group compared to 23 and 18% in the O-CSA group at 3 and 12 months following initiation of effective treatment (p = 0.04 and p = 0.6). The presence of O-CSA does not preclude an adequate response to CPAP. Adherence rate to PAP was poor in both the O-CSA and I-CSA groups. Further studies are needed to define optimal adherence rate and long-term benefits of PAP in CSA.

Effectiveness of Adaptive Servo Ventilation in the treatment of hypocapnic central sleep apnea of various etiologies

Central sleep apnea (CSA) occurs in clinical situations that induce hypocapnia and respiratory instability during sleep. This is true, not only in heart failure patients, but also in patients suffering from neurological diseases and idiopathic CSA. Adaptive Servo Ventilation (ASV) is frequently prescribed in France for the treatment of CSA, but only a few studies have evaluated ASV treatment with regards to long term effectiveness and compliance. Retrospective chart review in two French centers of the outcome of 74 CSA patients treated by ASV with a mean follow up on ASV of 36±18 months. Thirty-three of the 74 patients suffered from CSA related to heart failure (HF), whereas the 41 others exhibited CSA mainly associated with neurological disorders or idiopathic CSA. Mean ASV compliance was 5.2±2.6 and 5.9±2.9h per night in cardiac failure and non-cardiac failure patients, respectively. All patients significantly improved their apnea+hypopnea index (from 47.4±19.8 to 6.9±9.3/h [p<0.001]) and mean nocturnal SaO(2) (from 92.1±2.6% to 93.6±3.2% [p<0.001]). The Epworth sleepiness scale score was reduced from 10.2±5.2 to 6.5±3.9 (p<0.01) in compliant patients but not in non-compliant patients (less than 3h per night). Moreover, compliant cardiac failure patients demonstrated a significant improvement in their NYHA score [p<0.05]. Lastly, ASV significantly reduced chronic hyperventilation as assessed by blood gases. Our findings suggest that ASV is well tolerated and effective for most patients with hypocapnic central sleep apnea and chronic hyperventilation.

Idiopathic Central Sleep Apnea Presenting as Cheyne-Stokes Breathing

Address for correspondence Ho-Won Lee, MD Department of Neurology, School of Medicine, Kyungpook National University, 50 Samdeok-dong 2-ga, Jung-gu, Daegu 700-721, Korea Tel: +82-53-420-5769 Fax: +82-53-422-4265 E-mail: neuromd@knu.ac.kr A 70-year-old man had complained of excessive daytime sleepiness and fatigue for 3 years. He underwent an overnight polysomnography followed by a multiple sleep latency test which showed central sleep apnea with Cheyne-Stokes breathing (CSB) pattern. Further evaluation including magnetic resonance imaging of the brain could not find any cause of this sleep-disordered breathing. We describe the rare case of idiopathic central sleep apnea presenting as CSB pattern. J Korean Sleep Res Soc 2010;7:61-63

Effective Treatment for Idiopathic Central Sleep Apnea?

In this issue, Quadri et al.1 explore the treatment of idiopathic central sleep apnea (ICSA) with zolpidem. The authors defined ICSA as the presence of excessive daytime sleepiness (defined as an Epworth Sleepiness Scale, [ESS] ≥ 10), a central apnea-hypopnea index (CAHI) ≥ 10 events/hour, and an obstructive apnea-hypopnea index (OAHI) ≤ 5 events/hour. The study design was observational and involved small numbers of subjects (n = 20). Subjects with medical conditions associated with other forms of central sleep apnea were excluded (CHF with EF < 40%, diastolic dysfunction, history of transient ischemic attacks or stroke). In addition, other forms of nighttime respiratory disturbances (Cheyne Stokes respiration, obesity hypoventilation, hypercarbic lung disease) and other sleep disorders were excluded. Subjects who had already initiated therapy that might treat ICSA were also excluded. Subjects were offered therapy with 10 mg of zolpidem to be taken 30 minutes prior to sleep on a nightly basis. Repeat polysomnographic testing was performed 6-10 weeks later on zolpidem therapy.

Improvement of Idiopathic Central Sleep Apnea with Zolpidem

We hypothesized that the non-benzodiazepine hypnotic zolpidem would improve idiopathic central sleep apnea (ICSA) by enhancing sleep stability, resulting in fewer arousals, which in turn would lessen oscillation in arterial CO2 and produce a decrease in central apnea/hypopnea events. Zolpidem might also decrease ventilatory control responsiveness during arousals, thereby reducing hyperpnea, hypocapnia, and subsequent apneas. This was a case series in which all patients with ICSA seen in the Henry Ford Sleep Disorders Clinic from January 1, 2004, to December 31, 2006, were offered zolpidem, as well as other therapeutic options of acetazolamide, continuous positive airway pressure (CPAP), bilevel pressure support, or assist control ventilatory support. Those 20 patients who chose zolpidem were prescribed 10 mg at bedtime. After a therapeutic trial averaging 9 weeks, a follow-up polysomnogram showed that the overall apnea/hypopnea index (AHI) and central AHI (CAHI) decreased, 30.0 +/- 18.1 (SD) to 13.5 +/- 13.3 (p = 0.001), and 26.0 +/- 17.2 to 7.1 +/- 11.8 (p < 0.001), respectively, without an overall change in obstructive AHI or arterial oxygen saturation. The total number of arousals per hour decreased with zolpidem use, 24.0 +/- 11.6 to 15.1 +/- 7.7 (p < 0.001), leading to a significant improvement in sleep efficiency. There was a positive correlation between the decrease in CAHI and the arousal index. Consistent with the hypnotic effect of zolpidem, sleep latency decreased, stage 1 sleep percentage decreased, and stage 2 percentage increased (all significant), without changes in stage 3-4 or REM sleep. Excessive daytime sleepiness, measured by the Epworth Sleepiness Scale (ESS) decreased from 13 +/- 5 to 8 +/- 5 (p < 0.001). Three patients experienced a significant increase in obstructive events. In an open-label trial, ICSA patients studied experienced a decrease in central apnea/hypopneas with zolpidem. They also had improved sleep continuity and decreased subjective daytime sleepiness, without a worsening of oxygenation or obstructive events in the majority of patients. However, in the absence of a randomized, controlled trial, zolpidem cannot be recommended for treatment of ICSA at this time.

A Severely Sleep Deprived Patient

A 52-year-old man presented with a history of inability to maintain sleep for more than one hour, leading to dramatic excessive daytime sleepiness (EDS) (Epworth Sleepiness Scale score 24/24). He also complained of recurrent episodes of collapse during the day characterized by sudden loss of muscle tone and strength with preservation of consciousness, triggered by emotions. Background history included Type 1 diabetes and hypercholesterolemia. A previous MRI of the brain showed small infarcts in the right occipital lobe, and a 24-h electroencephalogram during a collapse had shown no epileptiform activity, with α rhythm being maintained. He had a body mass index (BMI) of 34, neck circumference of 17 inches, and a crowded oropharynx. His current medications included aspirin, ramipril, atorvastatin, and insulin. Neurological and systemic examination, arterial blood gases, and echocardiogram were normal. He was found to be positive for HLA DQB1*0602, and CSF examination revealed undetectable levels of hypocretin-1. A 2-week actigraphic tracing and a 5-min tracing from polysomnography are shown in Figure 1a–b. Figure 1a A trace of two weeks actigraphy: continuous movement throughout the 24 hour cycle consistent with severe sleep fragmentation. Figure 1b A 5 minutes trace of polysomnography in stage 2 sleep revealing recurrent episodes of central and some mixed apneas leading to marked desaturations and arousals. What is going on with this patient during sleep? What is the diagnosis? Narcolepsy with cataplexy syndrome associated with severe central sleep apnea (CSA), leading to dramatic sleep disruption and deprivation. Narcolepsy is a syndrome characterized by EDS, cataplexy, sleep paralysis, and hypnagogic hallucinations; it is closely associated with hypothalamic dysfunction and abnormalities of the neuropeptide hypocretin system. Many of the symptoms of narcolepsy can occur in any person who is severely sleep deprived, with the exception of cataplexy, which is unique for otherwise neurologically intact persons.1 CSA is mainly secondary to congestive heart failure or to brainstem structural damage and can lead to disrupted sleep. There are previous reports noting the occurrence of CSA in patients with narcolepsy.2 This association is uncommon; in a review of our own patients with definite narcolepsy, only 2 (2%) of 90 patients had mainly central apneas with an apnea-hypopnea index (AHI) > 5 (unpublished data). Eleven patients (12%) had AHI >5 caused mainly by obstructive apneas, which were correlated with BMI. The patient we present had clear-cut cataplexy, undetectable CSF hypocretin-1, and positive DQB1*0602 HLA type—all consistent with the diagnosis of narcolepsy with cataplexy syndrome. That was enough to explain his EDS. However, actigraphy revealed severe sleep fragmentation, which could be attributed to other associated disorders, such as periodic limb movements (PLMs) or obstructive sleep apnea. Polysomnography was deemed necessary and, surprisingly, revealed severe CSA. The CSA was not of the Cheyne-Stokes type, and with no obvious explanation for it (no brainstem pathology, no narcotics etc). Idiopathic CSA and narcolepsy are both rare conditions, and their coexistence as a coincidence seems unlikely. CSA is more likely to appear during sleep onset and sleep-wake transitions when respiratory instability is more pronounced. Narcolepsy is a syndrome of sleep state instability,3 often leading to repeated awakenings and sleep-wake transitions. PLMs or episodes of REM sleep behavior disorder (RBD), common in narcolepsy, may enhance sleep disruption. Recent data ascribes a role in breathing regulation to hypocretin. Nakamoura et al. found that spontaneous sleep apneas were more frequent in hypocretin knockout mice than wild-type mice and suggested that hypocretin plays a crucial role in preserving ventilation during sleep.3 Thus, a link between narcolepsy and malfunction of the sleep breathing mechanism may exist in humans when there is complete loss of hypocretin. The patient was treated with noninvasive ventilation, leading to marked decline of the apneic events and longer undisrupted sleep periods. However, his daytime alertness improved only slightly. The initiation of dexamphetamine and sodium oxybate led to a marked improvement of EDS and cataplexy.

Central Sleep Apnea in Heart Failure: Clinical Implications,Recognition, and Management

Central sleep apnea (CSA) is characterized by a lack of respiratory drive during sleep, resulting in repetitive periods of insufficient ventilation and compromised gas exchange. These nighttime breathing disturbances can lead to daytime impairment and poor cardiovascular outcomes. There are several types of CSA, including idiopathic CSA, high altitude-induced periodic breathing, obesity hypoventilation syndrome, drug-induced central apnea, and Cheyne-Stokes breathing pattern. While unstable ventilatory control during sleep is the hallmark of CSA, the pathophysiology and the prevalence of the various forms of CSA varies greatly. Among them, CSA associated with heart failure is well-studied in the respect of clinical impact and management strategy. Through this article, I will summarize the underlying pathophysiology, clinical impacts, and potential treatment of CSA occurring in subjects with heart failure.

Causality in the relationship between central sleep apnea and paroxysmal atrial fibrillation

The prevalence of central sleep apnea (CSA) is increased in patients with atrial fibrillation (AF) in addition to congestive heart failure [1]. Conversely, the prevalence of AF is increased in patients with idiopathic CSA in the absence of other cardiac disease [2]. The causality between CSA and AF and the etiologic relevance of congestive heart failure is not clear yet. A 52-year-old man with a stable three-vessel coronary artery disease was admitted because of suspected obstructive sleep apnea syndrome. The cardiorespiratory polygraphy revealed periodic breathing patterns following the onset of intermittent AF with a fast ventricular response and a heart rate up to 140 bpm (Figs. 1 and 2). CSA was not related to supine body position (Fig. 2). There were no ischemia-like electrocardiographic (ECG) changes associated with the development of CSA. Episodes of sinus rhythm with a heart rate of 60–80 bpm were accompanied by stable breathing patterns (Figs. 1 and 2). This finding was verified in a second polygraphy (Fig. 1). Transthoracic echocardiography revealed a marginal left ventricular hypertrophy and left ventricular diastolic dysfunction (ratio of early diastolic velocity to atrial velocity: e/a 85%). Holter-ECG and nocturnal capnometry remained without pathological findings.