Polygraphic Findings Research Articles

Simplified Barbed Reposition Pharyngoplasty (sBRP) as a treatment for OSA patients and Polygraphic findings

Simplified Barbed Reposition Pharyngoplasty (sBRP) as a treatment for OSA patients and Polygraphic findings

Fragmentary Hypnic Myoclonus and Other Isolated Motor Phenomena of Sleep.

Excessive fragmentary hypnic myoclonus, hypnic jerks, hypnagogic foot tremor, alternating leg muscle activation, and sleep-related cramps are less known sleep-related motor disorders (SRMDs). These manifestations are frequently missed or misinterpreted polygraphic findings that can be frequently confused with the more frequent SRMDs. These symptoms can present as isolated motor symptoms but can be also the cause of otherwise cryptogenic insomnias and somnolence. Expanding the knowledge on these isolated symptoms and defining their polygraphic and clinical features are essential for their identification. However, clear cut-offs to discern between the isolated phenomenon and the disorder are still to be found.

Obstructive Sleep Apnea and Wake-up Stroke – A 12 Months Prospective Longitudinal Study

Background: Wake-up stroke (WUS) are strokes that are noted upon awakening in patients previously going to bed in a normal state of health. The role of sleep abnormalities in WUS is uncertain. The objective was to determine clinical characteristics, respiratory abnormalities during sleep and outcomes in patients with WUS versus non-WUS. Methods: At baseline, patients with ischemic stroke were examined clinically and with a portable sleep recorder. Apnea-Hypopnea Index greater than or equal to 20 defined a cut-off severity index. At follow-up (3 and 12-months), patients were re-evaluated clinically and with questionnaires: Epworth Sleepiness Scale, Modified Rankin (MR) and Modified Barthel Index Results: Among all (N = 102, 64% male), hypertension (73%), Type 2 diabetes (29.4), heart disease (16.7%), physical inactivity (69.6%), smoking (32.4%) and alcohol consumption (17.6) were found. Apnea-Hypopnea Index (AHI) greater than 5 (92.9%), AHI greater than 15 (44.7%), AHI greater than or equal to 20 (35.3%) and AHI greater than 30 (11.8%) were registered. Cases with and without WUS did not differ regarding polygraphic findings. Long apneas (apnea duration > 20 s) was equally found in patients with WUS (23.1%) and non-WUS (23.7%). Type 2 diabetes mellitus (T2D) was independently associated with WUS (OR = 2.76; CI: 1.10-6.05; P = .03). Prospectively, symptom severity was not different between WUS and non-WUS. Overall, patients with OSA (IAH≥20) evolved with worse functional performance (MR, P = .02). Conclusions: Wake-up stroke occurred in approximately 1 of 3 of cases. Irrespective of WUS, half of the patients had moderate to severe sleep apnea; those with OSA (AHI≥ 20) evolved with worse functional performance after 1 year. WUS was associated with TDM reinforcing a relationship with cerebral small vessel disease.

A retrospective study on sleep-disordered breathing in Morquio-A syndrome.

Respiratory problems are common in Morquio-A syndrome (MPS IVA) but objective data on sleep-disordered breathing are scarce. The aim of our study was to review polygraphic (PG) findings and the need for noninvasive continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV) in children with MPS IVA. A retrospective review of the clinical charts and PG of 16 consecutive children (7 boys, mean age 10.5 ± 4.2 years) with MPS IVA seen over a period of 3 years was performed. The prevalence of obstructive sleep apnea (OSA) was 69% with only five patients, all younger than 10 years old, having a normal PG. Four patients had mild OSA (apnea-hypopnea index [AHI] ≥1.5 and <5 events/hr), three patients had moderate OSA (AHI ≥5 and <10 events/hr), and three patients had severe OSA (AHI ≥ 10 events/hr). Among the 10 patients with OSA, 3 had prior adenoidectomy ± tonsillectomy and 6 were on enzyme replacement therapy. Only one patient had a central apnea index >5 events/hr despite prior cervico-occipital decompression. Six patients, all older than 11 years old, were started on CPAP or NIV because of severe OSA (n = 4), nocturnal hypoventilation (n = 1), or impossibility to be weaned from NIV after an acute respiratory failure (n = 1). Prevalence of OSA is high in patients with MPS IVA, underlying the importance of a systematic screening for sleep-disordered breathing. CPAP and NIV are efficient and well accepted for treating sleep-disordered breathing.

Rationale and Design of the Turkish Sleep Apnea Database - TURKAPNE: A National, Multicenter, Observational, Prospective Cohort Study.

The primary aim of The Turkish Sleep Apnea Database (TURKAPNE) study is to generate a cross-sectional nationwide database for defining the clinical and polysomnographic characteristics of the patients with obstructive sleep apnea (OSA) in Turkey. In this ongoing project, all consecutive adults with suspected OSA are recruited from the sleep centers of the university and research hospitals in Turkey. Information on anthropometric data, educational status, driving license, smoking habits, alcohol use, comorbidities, drug use, questionnaires, polysomnographic, and/or cardiorespiratory polygraphic findings are recorded in a systematized Web-based report form. Blood glucose, lipids and other biochemical markers, lung function, and echocardiography measurements are optionally included. Follow-up data regarding treatment modality and compliance is assessed. Cross-sectional and longitudinal associations between OSA phenotypes and metabolic, pulmonary, and cardiovascular comorbidities as well as traffic accidents, and the impact of treatment will be further explored. We target a total sample of 10,000 participants. The study was registered with ClinicalTrials.gov (NCT02784977) in May 2016 and the first patient was recruited in October 2017. A total of 1911 participants from 19 centers have been enrolled in the study by May 31, 2018. The TURKAPNE study will contribute to a better understanding of the health-related burden of OSA phenotypes and its association with the comorbidities and adverse outcomes, including traffic accidents in Turkey. The results may also contribute to a more personalized approach and better management of varying OSA phenotypes with concomitant disorders.

Polygraphic findings of 47 cases with respiratory inhibition after crying

Objective: To report the polygraphic findings of infants with respiratory inhibition after crying (RIAC).Methods: We screened for RIAC among infants with a gestational age ≥36 weeks using our established method with cranial ultrasonography, SpO2 monitoring and polygraphy. RIAC is defined as central apnea that occurred immediately after crying with a decrease in SpO2 to <60%, followed by repeated irregular respiration and apnea as the respiration gradually recovered. The subjects were infants with RIAC for whom we could study the polygraphic findings in detail.Results: Forty-seven RIAC cases were included in the present analysis. The frequency of RIAC was 2.1 (1.2–7.0) times per 24 h. The maximum duration of respiratory inhibition was 78.0 (52.6–109.0) s. The maximum duration of SpO2 <60% during RIAC was 39.0 (9.8–93.2) s. The minimum SpO2 value during RIAC was 53.0% (42.2–58.0%). The minimum heart rate during RIAC was 103.0 (79.1–127.1) bpm.Conclusions: RIAC is observed among healthy infants, and they experience repeated prolonged hypoxemia.

Effect of Adaptive Servoventilation on Muscle Sympathetic Nerve Activity in Patients With Chronic Heart Failure and Central Sleep Apnea

BackgroundAdaptive servoventilation (ASV) improves cardiac function and sympathetic nerve activity in patients with heart failure (HF). However, the mechanisms underlying these improvements remain obscure. Methods and ResultsWe compared muscle sympathetic nerve activity (MSNA) and cardiorespiratory polygraphy and echocardiography findings at baseline and at 3.5 ± 0.8 months’ follow-up in 32 patients with HF (New York Heart Association functional class II or III; ejection fraction <45%) and central sleep apnea (CSA; apnea-hypopnea index [AHI] ≥15/h) who consented (n = 20; ASV group) or declined (n = 12; non-ASV group) to undergo ASV treatment. Compliance with ASV and changes in AHI were determined from data collected by integral counters in devices and from cardiorespiratory polygraphic findings, respectively. Ejection fraction and MSNA significantly changed in the ASV (both P < .001) but not the non-ASV group. Although changes in AHI and MSNA correlated, the average use of ASV did not. In contrast, changes in AHI and the average use of ASV were independent predictors of changes in ejection fraction (both P < .01). ConclusionsASV decreases MSNA and improves cardiac function in association with suppression of CSA in patients with HF.

Obstructive hypopnea and gastroesophageal reflux as factors associated with residual obstructive sleep apnea syndrome

Objective The mechanism of persisting obstructive sleep apnea (OSA) after adenotonsillectomy is not fully explained. The purpose of this study was to evaluate factors associated with residual OSA. The primary outcome measures were metabolic tests and polysomnographic respiratory indices in children with residual disease compared with children who were diagnosed with OSA but were untreated. Secondary outcome measures were acid gastroesophageal reflux indices recorded parallel to the sleep study. Methods In the one-year study consecutive series of patients with sleep disordered breathing hospitalized in a tertiary pediatric center were evaluated. Following the study protocol a sleep interview, physical examination, metabolic blood tests (serum leptin and the homeostasis model assessment index for insulin resistance, HOMA-IR) and an overnight polysomnography with pH-metry recording were performed. Children diagnosed with OSA were analyzed in two groups: I – residual OSA (after surgery), II – non-residual OSA (newly diagnosed). Logistic regression analysis was applied to obtain significant risk factors for prediction of OSA. Results Fifty-seven children (mean age ± SE, 6.9 ± 0.5 years; 66.7% boys) met the inclusion criteria and were enrolled in the study as residual ( n = 19) or non-residual OSA ( n = 38). The groups differed significantly in mean oxygen saturation, SpO 2 (94.3% vs. 96.2%; p = 0.018 respectively), in the Apnea Hypopnea Index, (20.6/h vs. 9.1/h; p < 0.03), the number of respiratory arousals with desaturation (2.2/h vs. 0.8/h; p < 0.03); mean intraluminal esophageal pH (5.36 vs. 5.86; p = 0.007) and the Reflux Index (9.61% vs. 4.35%; p = 0.003). The groups did not differ in total sleep time, tonsil size, BMI z-score and blood metabolic indices. Logistic regression analysis showed that residual OSA was significantly predicted by two polygraphic findings: the obstructive hypopnea index (OR 1.15; 95% CI 1.02–1.28; p = 0.014) and by the Reflux Index (OR 1.01; 95% CI 1.00–1.34; p = 0.042). Conclusions 1. Obstructive hypopneas, rather than obstructive apneas, persist after adenotonsillar surgery resulting in residual OSA. 2. Children with residual OSA are at higher risk of acid gastroesophageal reflux and should be evaluated for gastroesophageal reflux disease.

Executive summary of respiratory indications for polysomnography in children: an evidence-based review.

This comprehensive, evidence-based review provides a systematic analysis of the literature regarding the validity, reliability, and clinical utility of polysomnography for characterizing breathing during sleep in children. Findings serve as the foundation of practice parameters regarding respiratory indications for polysomnography in children. A task force of content experts performed a systematic review of the relevant literature and graded the evidence using a standardized grading system. Two hundred forty-three evidentiary papers were reviewed, summarized, and graded. The analysis addressed the operating characteristics of polysomnography as a diagnostic procedure in children and identified strengths and limitations of polysomnography for evaluation of respiratory function during sleep. The analysis documents strong face validity and content validity, moderately strong convergent validity when comparing respiratory findings with a variety of relevant independent measures, moderate-to-strong test-retest validity, and limited data supporting discriminant validity for characterizing breathing during sleep in children. The analysis documents moderate-to-strong test-retest reliability and interscorer reliability based on limited data. The data indicate particularly strong clinical utility in children with suspected sleep related breathing disorders and obesity, evolving metabolic syndrome, neurological, neurodevelopmental, or genetic disorders, and children with craniofacial syndromes. Specific consideration was given to clinical utility of polysomnography prior to adenotonsillectomy (AT) for confirmation of obstructive sleep apnea syndrome. The most relevant findings include: (1) recognition that clinical history and examination are often poor predictors of respiratory polygraphic findings, (2) preoperative polysomnography is helpful in predicting risk for perioperative complications, and (3) preoperative polysomnography is often helpful in predicting persistence of obstructive sleep apnea syndrome in patients after AT. No prospective studies were identified that address whether clinical outcome following AT for treatment of obstructive sleep apnea is improved in association with routine performance of polysomnography before surgery in otherwise healthy children. A small group of papers confirm the clinical utility of polysomnography for initiation and titration of positive airway pressure support. Pediatric polysomnography shows validity, reliability, and clinical utility that is commensurate with most other routinely employed diagnostic clinical tools or procedures. Findings indicate that the "gold standard" for diagnosis of sleep related breathing disorders in children is not polysomnography alone, but rather the skillful integration of clinical and polygraphic findings by a knowledgeable sleep specialist. Future developments will provide more sophisticated methods for data collection and analysis, but integration of polysomnographic findings with the clinical evaluation will represent the fundamental diagnostic challenge for the sleep specialist.

Cephalometric evaluation of children with nocturnal sleep-disordered breathing

The present study aimed to assess the cephalometric features in children with sleep-disordered breathing (SDB). The subjects were 70 children (34 boys and 36 girls, mean age 7.3, SD 1.72, range 4.2-11.9 years) with habitual snoring and symptoms of obstructive sleep disorder for more than 6 months. On the basis of overnight polygraphic findings, the subjects were further divided into subgroups of 26 children with diagnosed obstructive sleep apnoea (OSA), 17 with signs of upper airway resistance syndrome (UARS), and 27 with snoring. A control group of 70 non-obstructed children matched for age and gender was selected. Lateral skull radiographs were taken and cephalograms were traced and measured. The differences between the matched groups were studied using t-test for paired samples. Differences between the subgroups were studied using analysis of variance followed by Duncan's multiple comparison method. Children with SDB were characterized by an increased antero-posterior jaw relationship (P = 0.001), increased mandibular inclination in relation to the palatal line (P = 0.01), increased total (P = 0.019) and lower (P = 0.005) anterior face heights, a longer (P = 0.018) and thicker (P = 0.002) soft palate, smaller airway diameters at multiple levels of the naso- and oropharynx, larger oropharyngeal airway diameter at the level of the base of the tongue (P = 0.011), lower hyoid bone position (P = 0.000), and larger craniocervical angles (NSL-CVT, P = 0.014; NSL-OPT, P = 0.023) when compared with the non-obstructed controls. When divided into subgroups according to the severity of the disorder, OSA children deviated significantly from the control children especially in the oropharyngeal variables. Children with UARS and snoring also deviated from the controls, but the obstructed subgroups were not confidently distinguishable from each other by cephalometric measurements. Logistic regression analysis indicated that UARS and OSA were associated with decreased pharyngeal diameters at the levels of the adenoids (PNS-ad1) and tip of the uvula (u1-u2), an increased diameter at the level of the base of the tongue (rl1-rl2), a thicker soft palate, and anteriorly positioned maxilla in relation to the cranial base. Lateral cephalogram may thus reveal important predictors for SDB in children. Attention should be paid to pharyngeal measurements. Systematic orthodontic evaluation of SDB children is needed because of the effects of obstructed sleep on the developing craniofacial skeleton.

Microstructure of sleep in eating disorders: preliminary results.

Attempts to analyse the sleep structure of patients with eating disorders have so far led to conflicting results. Polygraphic findings suggest that patients with bulimia nervosa are not easily distinguishable from age-matched controls, whereas anorexic patients show some abnormalities in sleep efficiency and sleep architecture. Nevertheless, both bulimic and anorexic patients complain of poor quality sleep. The aim of this study was to evaluate the microstructure of sleep in anorexia and bulimia by analysing arousal (following the rules of the American Sleep Disorders Association) and the cyclic alternating pattern (CAP). The results confirmed the presence of sleep disturbances in eating disordered patients: an increase in arousal length and the CAP rate. They also seem to confirm the findings of previous studies suggesting that altered sleep in eating disordered patients may be related to their body mass index (BMI) and psychopathological status.

Prevalence of sleep-disordered breathing in children with Down syndrome: polygraphic findings in 108 children.

To assess the prevalence of sleep-disordered breathing in a nonselected group of children with Down syndrome and to determine significant predisposing factors for this condition. Prospective study. Tertiary care university hospital in Madrid, Spain. The study population included 108 consecutive children with Down syndrome (mean [SD] age, 7.9 [4.5] years; range, 1-18 years) independently of whether or not suggestive clinical features of sleep-disordered breathing were present. In addition to history, physical examination, and lateral radiographs of the nasopharynx, all participants underwent an overnight cardiorespiratory polygraphy at the hospital using a portable ambulatory device (Apnoescreen II plus). An apnea-hypopnea index of at least 3 was required for defining the presence of sleep-disordered breathing. The prevalence of sleep-disordered breathing was 54.6%, with a significantly higher prevalence in boys (64.7%) than in girls (38.5%) (P < .05). The group with sleep-disordered breathing was significantly younger (6.4 [3.9] years) than those with normal polysomnographic recordings (9.6 [4.6] years) (P < .001). In the multivariate analysis, age (less than 8 years old) (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.40, 8.06); male sex (OR, 3.32; 95% CI, 1.32, 8.12); and tonsillar hyperplasia (OR, 5.24; 95% CI, 1.52, 19.03) were significantly associated with sleep-disordered breathing. Body mass index, adenoid hyperplasia, previous tonsillectomy or adenoidectomy, congenital heart disease, malocclusion, and macroglossia did not affect the prevalence of sleep-disordered breathing. The prevalence of sleep-disordered breathing in children with Down syndrome is very high, particularly in boys. Tonsillar hyperplasia may play a role in the pathophysiology of sleep-disordered breathing in these patients. Adenoid hyperplasia, obesity, and congenital heart disease were not important risk factors for sleep-disordered breathing.

Age at onset of narcolepsy in two large populations of patients in France and Quebec.

Narcolepsy usually starts around adolescence; however, there is great variability in the clinical presentation of narcolepsy. To determine the age at onset in conjunction with severity of narcoleptic symptoms in two large populations of narcoleptic patients with a similar genetic background. Information on age at onset and severity of the condition was obtained in 317 patients with well-defined narcolepsy-cataplexy from Montpellier (France) and in 202 from Montreal (Canada). The mean age at onset was 23.4 years in Montpellier and 24.4 in Montreal. The age at onset was bimodal in two independent patient populations: a first peak occurring at 14.7 years, and a second peak occurring at 35. Age at onset clearly differentiates patients with a positive family history of narcolepsy (early onset) from those without a family history. Other clinical and polygraphic findings may indicate that young age at onset is associated with increased severity of the condition (higher frequency of cataplexy and decreased mean sleep latency on the Multiple Sleep Latency Test). Bimodal distribution of age at onset of narcolepsy was found in two independent patient populations. Our data suggest that age at onset is genetically determined.

Sleep-Related Breathing Disorders in Adolescents Aged 12 to 16 Years: Clinical and Polygraphic Findings

To determine the frequency, symptoms, and polygraphic features of sleep-related breathing disorders (SRBD) in adolescents aged 12 to 16 years. Cross-sectional study. Randomly selected secondary schools in the city of Seville, SPAIN: A general population sample of adolescents (n = 101; mean [+/- SD] age, 13.2 +/- 0.8 years). An 82-item questionnaire regarding anthropometric data and nocturnal and daytime symptoms suggestive of SRBD was administered. Symptoms were evaluated according to a 4-point frequency scale. Snorers answered "sometimes" or "often" in the question about snoring, and nonsnorers answered "never" or "rarely." All subjects underwent an overnight cardiorespiratory polygraphy at home. Twenty-nine percent of the subjects were snorers. Excessive daytime sleepiness was present in 14% of subjects, and sleep apnea was present in 3%. Polygraphy showed a respiratory disturbance index > or = 10 in 18 subjects (17.8%), but concurrent symptoms highly suggestive of SRBD were found in only 2 subjects (1.9%). Snorers had higher waist-to-hip ratios and a higher frequency of witnessed apnea or labored breathing as well as higher values of respiratory events as compared with nonsnorers. However, oximetry data were similar in both groups. In a nonselected group of adolescents aged 12 to 16 years, the frequency of symptoms potentially associated with SRBD was similar to that reported for younger children. Snoring was associated with a higher occurrence of other nocturnal symptoms, a more central pattern of body fat distribution, and a higher respiratory disturbance index as compared with nonsnorers. Although polygraphic abnormalities were mild, two cases of probable SRBD were found with a prevalence rate of 1.9%.

A video-polygraphic analysis of the cataplectic attack

Objectives and methods: To perform a video-polygraphic analysis of 11 cataplectic attacks in a 39-year-old narcoleptic patient, correlating clinical manifestations with polygraphic findings. Polygraphic recordings monitored EEG, EMG activity from several cranial, trunk, upper and lower limbs muscles, eye movements, EKG, thoracic respiration. Results: Eleven attacks were recorded, all of them lasting less than 1 min and ending with the fall of the patient to the ground. We identified, based on the video-polygraphic analysis of the episodes, 3 phases: initial phase, characterized essentially by arrest of eye movements and phasic, massive, inhibitory muscular events; falling phase, characterized by a rhythmic pattern of suppressions and enhancements of muscular activity, leading to the fall; atonic phase, characterized by complete muscle atonia. Six episodes out of 11 were associated with bradycardia, that was maximal during the atonic phase. Conclusions: Analysis of the muscular phenomena that characterize cataplectic attacks in a standing patient suggests that the cataplectic fall occurs with a pattern that might result from the interaction between neuronal networks mediating muscular atonia of REM sleep and neural structures subserving postural control.

Are periodic leg movements during sleep (PLMS) responsible for sleep disruption in insomnia patients?

On the basis of polygraphic findings, it has been suggested that periodic leg movements during sleep are not responsible for sleep impairment (Lugaresi et al., 1972). However, for some authors it is an important cause of insomnia (Guilleminault et al., 1975; Coleman, 1982). Thus, the relationship between periodic leg movements during sleep, sleep disruption and the complaint of patients is particularly complex. We investigated the macro- and micro-structure of sleep with and without leg movements in 10 PLMS patients complaining of insomnia to clarify whether periodic leg movements are responsible for sleep disruption. The total sleep time without periodic leg movements was significantly longer than sleep time with leg movements. Sleep time without leg movements was longer than sleep time with leg movements in stage 2, slow wave sleep (SWS) and rapid eye movement (REM) sleep. Short lasting awakenings were significantly more frequent during periodic leg movements associated sleep whilst long lasting awakenings were equally frequent during sleep with and without periodic leg movements. The percentage of the four electroencephalogram (EEG) activities (delta, theta, alpha and spindles) did not show any significant difference between periodic leg movements associated and not associated with sleep stages and total sleep time. The lack of significant differences in both the macro- and micro-structure of sleep and EEG activity content regarding the association with movements confirm the hypothesis that periodic leg movements did not primarily cause sleep disturbance.

5-51-01 Polygraphic findings in simulated microgravity conditions

5-51-01 Polygraphic findings in simulated microgravity conditions

The clinical spectrum of narcolepsy and idiopathic hypersomnia.

To better define the clinical spectra of narcolepsy and idiopathic hypersomnia, we retrospectively compared clinical and polygraphic findings and questionnaire results in groups of subjects with narcolepsy with or without cataplexy, idiopathic hypersomnia, insufficient sleep syndrome, mild sleep apnea, and excessive daytime sleepiness not otherwise specified. Sleep paralysis and sleep-related hallucinations were most frequent in narcolepsy-cataplexy, but their frequency did not differ between narcolepsy without cataplexy and idiopathic hypersomnia. Mean durations of nocturnal sleep, daytime naps, and morning grogginess were not increased in idiopathic hypersomnia compared with other groups. Among subjects without cataplexy, symptoms of sleep paralysis and sleep-related hallucinations were equally common in subjects with and without frequent sleep-onset REM periods. These findings suggest that the occurrence of these symptoms in subjects without classical narcolepsy-cataplexy is a function of factors other than a propensity for early onset of REM sleep and indicate a need to reevaluate diagnostic criteria for narcolepsy and idiopathic hypersomnia.

Polygraphic findings in young infants with Joubert's syndrome.

In three young infants with Joubert's syndrome polygraphic recordings were carried out in the awake state and during REM and NREM sleep in order to characterize the respiratory disorder associated with this condition. In all three states disturbed respiration parameters were found in variable amounts. The highest breath rate occurred in the awake state followed by REM and NREM sleep. The highest incidence of apnoea and periodic breathing was observed in NREM sleep, followed by REM sleep and the awake state.

Nocturnal sleep in multisystem atrophy with autonomic failure: polygraphic findings in ten patients

A nocturnal polysomnographic study with infrared video-monitoring was performed in ten patients with multisystem atrophy with autonomic failure (MSA-AF) (seven males, three females; median age: 54 years), selected irrespective of the presence of sleep complaints. The MSA-AF patients showed disrupted sleep patterns. Quantitative and qualitative alterations of REM sleep were found, some of which resembled those seen in patients with REM sleep behaviour syndrome. However, only one patient reported episodes of REM behaviour. Six patients showed arterial oxyhaemoglobin (HbSaO2) drops below 90% during sleep in relation to recurrent apnoeas or hypopnoeas (HbSaO2 nadir 70%). The apnoea hypopnoea index was above the upper limit of the normal range in three of these patients in the absence of obesity or bronchopulmonary diseases. Among patients with sleep-related breathing impairment, laryngeal stridor (three cases) or snoring (one case) were observed. Patients with sleep-related breathing disorders (SBD) exhibited a higher degree of autonomic dysfunction than patients without SBD.