Tertiary Sleep Disorders Center Research Articles

Stridor during sleep: description of 81 consecutive cases diagnosed in a tertiary sleep disorders center.

To describe the characteristics of stridor during sleep (SDS) in a series of adults identified by video-polysomnography (V-PSG). Retrospective clinical, V-PSG, laryngoscopic, and therapeutic data of patients diagnosed with SDS in a tertiary referral sleep disorders center between 1997 and 2017. A total of 81 patients were identified (56.8% males, age 61.8 ± 11.2 years). Related etiologies were multiple system atrophy (MSA), amyotrophic lateral sclerosis, spinocerebellar ataxia type 1, anti-IgLON5 disease, fatal familial insomnia, brainstem structural lesions, vagus nerve stimulation, recurrent laryngeal nerve injury, the effect of radiotherapy on the vocal cords, cervical osteophytes, and others. Stridor during wakefulness coexisted in 13 (16%) patients and in MSA was only seen in the parkinsonian form. Laryngoscopy during wakefulness in 72 (88.9%) subjects documented vocal cord abductor impairment in 65 (90.3%) and extrinsic lesions narrowing the glottis in 2 (2.4%). The mean apnea-hypopnea index (AHI) was 21.4 ± 18.6 and CT90 was 11.5 ± 19.1. Obstructive AHI > 10 occurred in 52 (64.2%) patients and central apnea index >10 in 2 (2.4%). CPAP abolished SDS, obstructive apneic events and oxyhemoglobin desaturations in 58 of 60 (96.7%) titrated patients with optimal pressure of 9.0 ± 2.3 cm H20. Tracheostomy in 19 (23.4%) and cordotomy in 3 (3.7%) subjects also eliminated SDS. SDS in adults is linked to conditions that damage the brainstem, recurrent laryngeal nerve, and vocal cords. V-PSG frequently detects obstructive sleep apnea and laryngoscopy usually shows vocal cord abductor dysfunction. CPAP, tracheostomy, and laryngeal surgery abolish SDS.

Use of a limited-channel device for obstructive sleep apnoea diagnosis in a tertiary sleep disorders centre.

A major impediment to the provision of obstructive sleep apnoea (OSA) treatment is reliance on labour-intensive and costly laboratory-based polysomnography (PSG). To investigate if measurement of oximetry and nasal flow through the ApneaLink device (AL) could identify patients with moderate-severe OSA among those referred for PSG to a tertiary sleep service. New referrals to The Prince Charles Hospital Sleep Disorders Centre were assessed for suitability. Demographics, anthropometrics, Epworth Sleepiness and OSA50 scores were collected. Exclusion criteria included age <18 years, pregnancy, significant cognitive impairment, poorly controlled psychiatric disorder, domiciliary oxygen and prior OSA treatment. Participants underwent concurrent type 1 PSG and AL assessments. One hundred participants had a mean age of 55 years (standard deviation 17) and were 49% male. Forty-eight (48%) had moderate-severe OSA on PSG. Composite variable AL 3% oxygen desaturation index ≥16 and AL apnoea-hypopnoea index (AHI) ≥15 had receiver operator characteristic area under the curve of 0.87, sensitivity of 80% and specificity of 94% for PSG AHI ≥15. The three false-positives seen with this composite variable had PSG AHI 11-14 and Epworth Sleepiness Score 6-17. The various composites of AL, anthropometric and questionnaire variables did not improve the AUC or specificity but did improve sensitivity. AL is useful in the diagnosis of moderate-severe OSA in patients referred to a tertiary sleep disorders centre. This could lessen reliance on PSG, expedite OSA care, lead to significant cost savings and make diagnosis of OSA more available in non-urban areas.

Mortality and morbidity in obstructive sleep apnoea-hypopnoea syndrome: results from a 30-year prospective cohort study.

BackgroundObstructive sleep apnoea–hypopnoea syndrome (OSAHS) carries substantial negative health consequences. This study examines factors affecting mortality and morbidity according to continuous positive airway pressure (CPAP) use and predictors affecting CPAP adherence in a longitudinal cohort of OSAHS patients.Materials and methodsThis prospective, cohort study comprised 4502 patients who were diagnosed with OSAHS at a tertiary sleep disorders centre between 1982 and 2003. Of these, 1174 patients completed follow-up in 2012. Data collected included anthropometric, sleep and demographic characteristics, including comorbidities, ongoing medications and CPAP adherence. Patients were followed up for an average of 14.8±3.7 years.ResultsImputation analysis showed that long-term CPAP users (>5 years) were 5.63 times more likely to be alive at study end than non-CPAP users (95% CI: 4.83–6.58, p<0.001) and 1.74-times more likely than short-term CPAP users (≤5 years) (95% CI: 1.49–2.02, p<0.001). Females had a significantly higher mortality rate during the follow-up period (26.8% versus 19.6%, p<0.001). Respiratory mortality was more common in patients with OSAHS, in particular those who did not use CPAP, compared to the general population (17.2% versus 12.2%, p=0.002 respectively), whereas deaths from cancer were less common compared to the general population (16.2% versus 25.6%, p<0.001). Compared to CPAP users, non-CPAP-users had a significantly increased incidence of type II diabetes mellitus (DMII) (27.9% versus 18.7%, p=0.003), ischaemic heart disease (IHD) (25.5% versus 12.7%, p<0.001) and myocardial infarction (MI) (14.7% versus 4.2%, p<0.001) at long-term follow-up.ConclusionsLong-term CPAP use in men and women with OSAHS reduces mortality and decreases the incidence of DMII and cardiovascular disease.

Effectiveness and side-effect profile of stimulant therapy as monotherapy and in combination in the central hypersomnias in clinical practice.

Effectiveness and side-effect profile data on pharmacotherapy for daytime sleepiness in central hypersomnias are based largely upon randomized controlled trials. Evidence regarding the use of combination therapy is scant. The aim of this study was to examine the effectiveness and occurrence of drug-related side effects of these drugs in routine clinical practice. Adult patients diagnosed with a central hypersomnia during a 54-month period at a tertiary sleep disorders centre were identified retrospectively. Side effects were recorded at every follow-up visit. A total of 126 patients, with 3275 patient-months of drug exposure, were categorized into narcolepsy type 1 (n=70), narcolepsy type 2 (n=47) and idiopathic hypersomnia (n=9). Modafinil was the most common drug used as a first-line treatment (93%) and in combination therapy (70%). Thirty-nine per cent of the patients demonstrated a complete, 25% partial and 36% a poor response to treatment. Combination treatment improved daytime sleepiness in 55% of the patients with residual symptoms despite monotherapy. Sixty per cent of patients reported side effects, and 30% reported treatment-limiting side effects. Drugs had similar side-effect incidence (P=0.363) and their side-effect profile met those reported in the literature. Twenty-seven per cent of the patients received combination treatment and had fewer side effects compared to monotherapy (29.4% versus 60%, respectively, P=0.001). Monotherapy appears to achieve satisfactory symptom control in most patients with central hypersomnia, but significant side effects are common. Combination therapy appears to be a useful and safe option in patients with refractory symptoms.

Investigating Cost Implications of Incorporating Level III At-Home Testing into a Polysomnography Based Sleep Medicine Program Using Administrative Data.

Objective Obstructive sleep apnea is a common problem, requiring expensive in-lab polysomnography for proper diagnosis. Home monitoring can provide an alternative to in-lab testing for a subset of OSA patients. The objective of this project was to investigate the effect of incorporating home testing into an OSA program at a large, tertiary sleep disorders centre. Methods The Sleep Disorders Centre in Saskatoon, Canada, has been incorporating at-home testing into their diagnostic pathways since 2006. Administrative data from 2007 to 2013 were extracted (10030 patients) and the flow of patients through the program was followed from diagnosis to treatment. Costs were estimated using 2014 pricing and were stratified by disease attributes and sensitivity analysis was applied. Results The overall costs per patient were $627.40, with $419.20 for at-home testing and $746.20 for in-lab testing. The cost of home management would rise to $515 if all negative tests were required to be confirmed by an in-lab PSG. Discussion Our review suggests that at-home testing can be cost-effective alternative to in-lab testing when applied to the correct population, specifically, those with a high pretest probability of obstructive sleep apnea and an absence of significant comorbidities.

Sleep-stage sequencing of sleep-onset REM periods in MSLT predicts treatment response in patients with narcolepsy.

Current treatment recommendations for narcolepsy suggest that modafinil should be used as a first-line treatment ahead of conventional stimulants or sodium oxybate. In this study, performed in a tertiary sleep disorders centre, treatment responses were examined following these recommendations, and the ability of sleep-stage sequencing of sleep-onset rapid eye movement periods in the multiple sleep latency test to predict treatment response. Over a 3.5-year period, 255 patients were retrospectively identified in the authors' database as patients diagnosed with narcolepsy, type 1 (with cataplexy) or type 2 (without) using clinical and polysomnographic criteria. Eligible patients were examined in detail, sleep study data were abstracted and sleep-stage sequencing of sleep-onset rapid eye movement periods were analysed. Response to treatment was graded utilizing an internally developed scale. Seventy-five patients were included (39% males). Forty (53%) were diagnosed with type 1 narcolepsy with a mean follow-up of 2.37 ± 1.35 years. Ninety-seven percent of the patients were initially started on modafinil, and overall 59% reported complete response on the last follow-up. Twenty-nine patients (39%) had the sequence of sleep stage 1 or wake to rapid eye movement in all of their sleep-onset rapid eye movement periods, with most of these diagnosed as narcolepsy type 1 (72%). The presence of this specific sleep-stage sequence in all sleep-onset rapid eye movement periods was associated with worse treatment response (P = 0.0023). Sleep-stage sequence analysis of sleep-onset rapid eye movement periods in the multiple sleep latency test may aid the prediction of treatment response in narcoleptics and provide a useful prognostic tool in clinical practice, above and beyond their classification as narcolepsy type 1 or 2.

Motivational interviewing (MINT) improves continuous positive airway pressure (CPAP) acceptance and adherence: A randomized controlled trial.

Adherence to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA) is poor. We assessed the effectiveness of a motivational interviewing intervention (motivational interview nurse therapy [MINT]) in addition to best practice standard care to improve acceptance and adherence to CPAP therapy in people with a new diagnosis of OSA. One hundred six Australian adults (69% male) with a new diagnosis of OSA and a clinical recommendation for CPAP treatment were recruited from a tertiary sleep disorders center. Participants were randomly assigned to receive either 3 sessions of a motivational interviewing intervention (MINT; n = 53; mean age = 55.4 years) or no intervention (control; n = 53; mean age = 57.74 years). The primary outcome was the difference between the groups in objective CPAP adherence at 1-month, 2-month, 3-month, and 12-month follow-ups. Fifty (94%) participants in the MINT group and 50 (94%) participants in the control group met all inclusion and exclusion criteria and were included in the primary analysis. The number of hours of CPAP use per night in the MINT group at 3 months was 4.63 hr and was 3.16 hr in the control group (p = .005). This represents almost 50% better adherence in the MINT group relative to the control group. Patients in the MINT group were substantially more likely to accept CPAP treatment. MINT is a brief, manualized, effective intervention that improves CPAP acceptance and objective adherence rates compared to standard care alone.

Comparison of actigraphic, polysomnographic, and subjective assessment of sleep parameters in sleep-disordered patients

Objective: Comparison of polysomnography (PSG)-derived sleep parameters (total sleep time, sleep efficiency, and number of awakenings) to those derived from actigraphy and subjective questionnaires. Background: Actigraphy is commonly used to assist sleep specialists in the diagnosis of various sleep and circadian-rhythm disorders. However, few validation studies incorporate large sample sizes, typical sleep clinic patients, or comparisons with subjective reports of sleep parameters. Methods: Clinical series with 100 consecutive sleep-disordered patients (69 men, 31 women, mean age of 49±14.7 years) at a tertiary sleep disorders center. Sensitivity, specificity, and accuracy measures were obtained from epoch-by-epoch comparison of PSG and actigraphic data. Subjective sleep parameter data were derived from questionnaires given to subjects in the morning following their recording night. Results: We found that total sleep time and sleep efficiency did not significantly differ between PSG data and the combined data obtained from actigraphy and subjective reports. Using a high-threshold (low-wake-sensitivity) actigraphic algorithm, the number of awakenings was not significantly different from those detected by PSG. Conclusions: We recommend the use of subjective data as an adjunct to actigraphic data in estimating total sleep time and sleep efficiency in sleep-disordered patients, especially those with disorders of excessive somnolence.