Multiple sleep latency test and polysomnography in patients with central disorders of hypersomnolence

A multiple sleep latency test (MSLT) with occurrence of sleep onset REM periods (SOREMP) is considered one of the central diagnostic criteria for narcolepsy according to the International Classification of Sleep Disorders, but its sensitivity and specificity have been questioned. This study aims to describe MSLT and polysomnography (PSG) findings, including frequency and distribution of SOREMP during the day, in a large cohort of patients with central disorders of hypersomnolence (CDH).We retrospectively analyzed electrophysiological data from MSLT and PSG in 370 consecutive patients with narcolepsy type 1 (NT1, n = 97), type 2 (NT2, n = 31), idiopathic hypersomnia (IH, n = 48), nonorganic hypersomnia (NOH, n = 116) and insufficient sleep syndrome (ISS, n = 78).NT1 and NT2 patients had a significantly shorter mean Sleep Latency (mSL) and REM-Latency (REML) in MSLT and PSG. SOREMP occurred more frequently in narcoleptic vs. non-narcoleptic patients in MSLT and PSG. Occurrence of 3 or more SOREMP in MSLT and a SOREMP in PSG had a very high specificity and positive predictive value (98%/96% and 100% respectively), however relatively low sensitivity (65% and 45% respectively).NT1 more than NT2 patients have shorter mSL and more frequent SOREMP in MSLT and shorter SL as well as REML during nocturnal PSG. Increasing numbers of SOREMP in MSLT and especially SOREMP during PSG increase specificity on the expense of sensitivity in diagnosing narcolepsy. Therefore, frequency of SOREMP in MSLT naps and PSG can help to discriminate but not clearly separate narcoleptic from non-narcoleptic patients.     

Utility of the sleep stage sequence preceding sleep onset REM periods for the diagnosis of narcolepsy: a study in a Japanese cohort

BackgroundThe minimum narcolepsy criteria “mean sleep latency (MSL) ≤8 min and ≥2 sleep onset rapid eye movement (REM) periods (SOREMPs) on polysomnography (PSG) and the multiple sleep latency test (MSLT),” according to The International Classification of Sleep Disorders, Third Edition (ICSD-3), are not specific to narcolepsy. Recently, the characteristic sleep stage sequences preceding SOREMPs in narcolepsy have received attention, but their diagnostic utility remains unclear.MethodsWe retrospectively reviewed PSG/MSLT records and chart data for 102 Japanese patients with hypersomnia and at least one SOREMP. We examined the sporadic rates of two sleep stage sequences preceding the SOREMPs—wakefulness or stage 1 to REM (W/S1→R) and stage 2 to REM (S2→R)—comparing these between patient groups with narcolepsy type 1 (N = 28), narcolepsy type 2 (N = 19), and other hypersomnia (N = 55). We also examined the utility of three simple indices using the occurrence of W/S1→R SOREMPs for distinguishing between narcolepsy and other hypersomnia in patients who satisfied the minimum narcolepsy criteria.ResultsW/S1→R SOREMPs were significantly more frequent in narcolepsy than in other hypersomnia, and this tendency was also observed even in the patients who satisfied the minimum narcolepsy criteria. The three indices had moderate sensitivities and specificities for distinguishing between narcolepsy and other hypersomnia in patients satisfying the minimum narcolepsy criteria.ConclusionsThe W/S1→R pattern was observed significantly more frequently in narcolepsy than in other hypersomnia, suggesting it may help with differentiating narcolepsy from other hypersomnia in patients demonstrating the narcolepsy criteria, although its ability to do so may be modest.     

Effects of an individualized exercise training program on severity markers of obstructive sleep apnea syndrome: a randomised controlled trial

ObjectiveObstructive sleep apnea (OSA) is a high prevalent disorder with severe consequences including sleepiness, metabolic, and cardiovascular disorders. The aim of this study was to assess the effect of an individualized exercise-training (IET) program with educational sessions vs educational sessions alone on severity markers of OSA over an eight-week duration.MethodsThis was a randomised, controlled, parallel-design study. In sum, 64 patients with moderate-to-severe OSA (apnea-hypopnea index AHI 15–45/hour), low physical activity level (Voorrips<9), body-mass index (BMI) <40 kg/m² were included in intervention group (IG) or control group (CG), and 54 patients finished the study. All underwent polysomnography (PSG), multiple sleep latency test (MSLT), constant workload exercise test, blood samples and fulfilled questionnaires twice. The primary endpoint was the change in apnea-hypopnea (AHI) at eight weeks from baseline. Main secondary endpoints were daytime sleepiness assessed by questionnaire and objective tests.ResultsNo significant between-group differences were found for changes in AHI. A reduction in AHI was found in IG only (p = 0.005). Compared to CG, exercise training leads to a greater decrease in AHI during REM sleep (p = 0.0004), with a significant increase in mean daytime sleep latency (p = 0.02). Between-group differences were significant for weight reduction, severity of fatigue, insomnia and depressive symptoms with trend for sleepiness symptoms.ConclusionsIn adult patients with moderate-to-severe OSA, IET did not decrease AHI compared to the control group but improved markers of severity of OSA, in particular AHI in rapid eye movement (REM) sleep and objective daytime sleepiness. Adding personalized exercise training to the management of patients with OSA should be considered.ClinicalTrials.gov identifierNCT01256307.     

Sleep-stage transitions during polysomnographic recordings as diagnostic features of type 1 narcolepsy

ObjectiveType 1 narcolepsy/hypocretin deficiency is characterized by excessive daytime sleepiness, sleep fragmentation, and cataplexy. Short rapid eye movement (REM) latency (≤15 min) during nocturnal polysomnography (PSG) or during naps of the multiple sleep latency test (MSLT) defines a sleep-onset REM sleep period (SOREMP), a diagnostic hallmark. We hypothesized that abnormal sleep transitions other than SOREMPs can be identified in type 1 narcolepsy.MethodsSleep-stage transitions (one to 10 epochs to one to five epochs of any other stage) and bout length features (one to 10 epochs) were extracted from PSGs. The first 15 min of sleep were excluded when a nocturnal SOREMP was recorded. F_0.1 measures and receiver operating characteristic curves were used to identify specific (≥98%) features. A data set of 136 patients and 510 sex- and age-matched controls was used for the training. A data set of 19 cases and 708 sleep-clinic patients was used for the validation.Results(1) ≥5 transitions from ≥5 epochs of stage N1 or W to ≥2 epochs of REM sleep, (2) ≥22 transitions from ≥3 epochs of stage N2 or N3 to ≥2 epochs of N1 or W, and (3) ≥16 bouts of ≥6 epochs of N1 or W were found to be highly specific (≥98%). Sensitivity ranged from 16% to 30%, and it did not vary substantially with and without medication or a nocturnal SOREMP. In patients taking antidepressants, nocturnal SOREMPs occurred much less frequently (16% vs. 36%, p < 0.001).ConclusionsIncreased sleep-stage transitions notably from ≥2.5 min of W/N1 into REM are specifically diagnostic for narcolepsy independent of a nocturnal SOREMP.     

Findings of routine nocturnal polysomnography in children with Down syndrome: a retrospective cohort study

Study objectiveChildren with Down syndrome (DS) are at risk for sleep disorders including; obstructive sleep apnea (OSA). Although OSA is diagnosed by polysomnography (PSG), the practicality of PSG in DS is questionable. Further, OSA treatment efficacy in DS is largely unknown given the challenges of PSG. Our aims were to review (i) the feasibility of PSG, and (ii) the efficacy (improvement in obstructive apnea hypopnea index (OAHI)) of OSA treatment using follow-up PSG in DS.MethodsRetrospective review of patients aged <21 years with DS who underwent PSG from October 2016 to June 2019. Successful PSG was determined using total sleep time (TST). PSG following treatment with adenotonsillectomy (AT) or positive airway pressure (PAP) was evaluated and compared to pre-treatment.ResultsAmong 248 patients with DS, only 11(4.4%) had unsuccessful PSG (TST<1h). Of the 237 successful studies (age: 7.9 ± 0.3y), average TST and sleep efficiency was 5.6 ± 0.1h and 79.5 ± 1.3%. 41 had post-AT PSG and 11(27%) achieved OSA cure (OAHI<2) with all demonstrating improved SE (p = 0.01) and OAHI (p = 0.0003). Multivariate analysis revealed only age was predictive (p = 0.003) of residual OSA post-AT. Of 24 children who underwent PAP titration, 20(83%) tolerated titration with improved OAHI (p = 0.01), however, no significant improvements in SE were observed.ConclusionsIn a large cohort of DS children, PSG was well tolerated. Following AT or PAP therapy, post treatment PSG confirmed efficacy, although residual OSA was identified. PSG is thus both feasible and useful in identifying OSA, OSA treatment response and should guide in decision making in children with DS.     

Prevalence and neurophysiological correlates of sleep disordered breathing in pediatric type 1 narcolepsy

Study objectivesTo investigate the prevalence and neurophysiological correlates of obstructive sleep disordered breathing (OSA) in type 1 narcolepsy (NT1) children and adolescents.MethodsThirty-eight, drug-naïve, NT1 children and adolescents and 21 age- and sex-balanced clinical controls underwent nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT). According to the rules for pediatric population, an obstructive apnea-hypopnea index (Obstructive AHI) ≥ 1 (comprising obstructive and mixed events), defined comorbid OSA.ResultsNT1 children showed higher prevalence of overweight/obesity and severe nocturnal sleep disruption (lower sleep efficiency, and increased N1 sleep stage percentage) coupled with higher motor activity (periodic limb movement index [PLMi] and REM atonia index) compared to clinical controls. Sleep-related respiratory variables did not differ between NT1 and clinical controls (OSA prevalence of 13.2% and 4.8%, respectively). NT1 children with OSA were younger and showed lower N2 sleep stage percentage and higher PLMi than NT1 children without comorbid OSA. Overweight/obesity was not associated with OSA in NT1.ConclusionsDespite higher body mass index (BMI), OSA prevalence did not differ between children with NT1 and clinical controls. OSA in pediatric NT1 patients is a rare and mild comorbidity, further contributing to nocturnal sleep disruption without effects on daytime sleepiness.     

Hypersomnolence and narcolepsy; a pragmatic diagnostic neurophysiological approach

Out of a group of 250 consecutive patients who were examined for various disorders of sleep and waking at Ghent University Hospital within a period of 24 months, 30 patients with hypersomnolence associated with a suspected underlying neurological etiology were selected. The population consisted of 15 males and 15 females with mean age of 36 years (range: 16-60 years). Twenty-one patients had had hypersomnolence for more than 2 years. All patients underwent a single night polysomnography (PSG) and a 4-nap multiple sleep latency test (MSLT). PSG was normal in 23 patients. Sleep onset REM period (SOREMP) was defined as the occurrence of REM sleep within 15 min. after initiation of sleep. PSG demonstrated SOREMP's in only 1 patient and showed evidence of obstructive sleep apnea in 4 patients. Two patients had a low sleep efficiency. MSLT demonstrated hypersomnolence in 17 patients of whom 6 showed SOREMP. Significant hypersomnolence was defined as a mean sleep latency < or = 5 min. 4 patients fulfilled the classical clinical and polygraphic criteria (> or = 2 SOREMP) of narcolepsy. In 8 patients the tentative diagnosis of idiopathic CNS hypersomnolence was made. 13 patients did not sleep during MSLT. These results emphasize the relative importance of MSLT. Our limited 4-nap MSLT protocol proved useful in distinguishing narcolepsy from idiopathic CNS hypersomnolence.     

Utility of measuring CSF hypocretin-1 level in patients with suspected narcolepsy

ObjectivesThe patho-aetiology of narcolepsy Type I (NT1) is the loss of hypocretin-1 secreting neurons in the hypothalamus. Diagnostic criteria for NT1 include excessive daytime sleepiness (EDS) for at least three months not explained by any other condition, cataplexy and cerebrospinal fluid (CSF) hypocretin-1 concentrations lower than 110 pg/ml. In this study we evaluated the utility of measuring CSF hypocretin-1 levels in patients with suspected narcolepsy (N).MethodsThe study included 29 consecutively recruited patients at a tertiary sleep centre presenting with EDS for exclusion of N. All patients were examined using an extensive clinical interview followed by two weeks of actigraphy and sleep diary recordings, polysomnography (PSG) and multiple sleep latency testing (MSLT). Additionally, HLA-typing, urinary screening for substances of abuse and a lumbar puncture to measure CSF hypocretin-1 expression using radioimmunoassay were carried out.ResultsIn sum, 19 patients (66%) had a CSF hypocretin-1 level <110 pg/ml, of whom two had current severe depression without any features of narcolepsy except EDS. The predictive potential of hypocretin-1 measurement in diagnosing narcolepsy revealed a positive predictive value (PPV) of 89%, a specificity of 83%, with both negative predictive value (NPV) and sensitivity equal to 100%.ConclusionsDespite a high sensitivity and specificity, the MSLT is not always a reliable diagnostic test for narcolepsy and where this uncertainty exits, CSF hypocretin-1 concentrations <110 pg/ml can be useful. However, due to a lower PPV and specificity at this cut-off, it may also not be entirely reliable as a stand-alone diagnostic test, particularly in the context of severe depression.     

Efficacy and safety of solriamfetol for excessive sleepiness in narcolepsy and obstructive sleep apnea: findings from randomized controlled trials

BackgroundSolriamfetol is developed for the treatment of excessive sleepiness in adult patients with narcolepsy and obstructive sleep apnea (OSA). No systematic review of existing literature has been investigated before. Therefore, the meta-analysis is conducted to assess the efficacy and safety of solriamfetol for excessive sleepiness in narcolepsy and OSA.MethodsPubMed, Embase and Cochrane Library databases were searched from earliest date to July 2020 for randomized controlled trials (RCTs) and the primary outcomes were change from baseline in mean sleep latency and Epworth Sleepiness Scale (ESS).ResultsWe pooled 1177 patients from five RCTs and found solriamfetol led to a significant increment in mean sleep latency (MD = 9.52, 95% CI: 7.60 to 11.44, P < 0.00001) and a reduction in ESS score (MD = −3.74, 95% CI: −4.38 to −3.09, P < 0.00001) compared with placebo. The proportion of patients with at least one adverse event was significantly increased in solriamfetol group (RR = 1.42, 95% CI: 1.24 to 1.64, P < 0.00001), while no statistical differences existed in the risk of at least one serious adverse event between solriamfetol and controlled group (RR = 0.95, 95% CI: 0.24 to 3.77, P = 0.39).ConclusionsA dose of 150 mg solriamfetol is proved to be the appropriate and stable dose for excessive sleepiness. In addition, solriamfetol showed good efficacy for excessive sleepiness in narcolepsy and OSA but also significantly increases the risk of adverse events.     

High prevalence of ADHD symptoms in unmedicated youths with post-H1N1 narcolepsy type 1

ObjectivesTo characterize attention deficit-hyperactivity disorder (ADHD) symptoms in unmedicated post-H1N1 narcolepsy type 1 (NT1) youths, and explore associations between ADHD symptoms and the narcolepsy phenotype.MethodsA total of 50 consecutively enrolled post-H1N1 NT1 youths (7–20 years, 62% females, 98% HLA-DQB1106:02-positive, 98% CSF hypocretin-1 deficient, 88% vaccinated) were assessed after two weeks off medication for ADHD (ADHD diagnosis pre/post-narcolepsy, parent-rated ADHD symptoms) and narcolepsy-phenotyped (semi-structured interview, Stanford Sleep Questionnaire, Epworth Sleepiness Scale, polysomnography (PSG), Multiple Sleep Latency Test (MSLT)).ResultsIn sum, 26 (52%) and 15 (30%) of participants had ADHD symptoms above and below the clinical significant cut-off, respectively, while 9 (18%) had no ADHD symptoms. High values were found for ADHD total score (mean (SD), 17.9 (9.5)) and ADHD subscores (inattentive score, 11.0 (6.3); hyperactive/impulsivity score, 6.9 (4.7)). These were significantly higher than previously reported in a mainly medicated narcolepsy cohort (p < 0.0001). Age, gender and disease duration did not influence scores. Two participants (4%) had ADHD diagnosis prior to narcolepsy onset. ADHD symptoms were correlated with parent-rated, but not with patient rated ESS scores, objective sleepiness (mean sleep latency), sleep fragmentation (sleep stage shift index, awakening index), or CSF hypocretin-1 level.ConclusionComorbid ADHD symptoms were more prevalent in unmedicated post-H1N1 NT1 youths than previously reported in mainly medicated pediatric narcolepsy cohorts. The high prevalence was not due to pre-existing ADHD and generally not correlated with core narcolepsy sleep/wake phenotype characteristics, indicating that the ADHD symptoms were not a direct consequence of disturbed sleep or daytime sleepiness.     

Subjective nocturnal symptoms have different associations with depressive symptoms and anxiety than with daytime sleepiness in patients with obstructive sleep apnea

BackgroundWe determined the relationships among the subjective symptoms of sleep apnea and daytime sleepiness, depressive symptoms, and anxiety in adults with obstructive sleep apnea (OSA).MethodsWe developed the Subjective Apnea Severity Questionnaire (SASQ) to measure subjective OSA symptoms during the night and on waking in the morning. Construct validity and reliability were assessed. The Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and State Scale of State Trait Anxiety Inventory (STAI-S) were applied. Multiple linear regression analyses were performed, and the results were adjusted for several confounders.ResultsA total of 337 OSA patients were included. The SASQ consists of eight items with three domains. Cronbach's α for the SASQ was 0.657. The mean SASQ score was 1.35 ± 0.59. Symptoms related to nocturnal breathing difficulties were associated with polysomnographic (PSG) respiratory parameters. In the adjusted models, total SASQ scores were associated with ESS scores but not with BDI or STAI-S scores. Unlike other symptom groups, nocturnal breathing difficulties tended toward a positive relationship with ESS scores (p = 0.076), but were negatively related to BDI scores (p = 0.003) and STAI-S scores (p = 0.012). Symptoms related to nocturnal awakening or morning waking were either positively related or unrelated to ESS, BDI, and STAI-S scores.ConclusionsThe subjective OSA symptoms measured via the SASQ were associated with daytime sleepiness in adults with OSA, but not with depressive symptoms or anxiety. Nocturnal breathing difficulties were positively related to daytime sleepiness, but negatively related to depressive symptoms and anxiety.     

Clinical characteristics of sleep apnea in middle-old and oldest-old inpatients: symptoms and comorbidities

BackgroundObstructive sleep apnea (OSA) is prevalent in older adults but still underdiagnosed for many reasons, such as underreported symptoms, non-specific ones because of the comorbidities and polypharmacy, or the social belief of sleep problems as normal with aging.ObjectivesTo identify salient symptoms and comorbidities associated with OSA, diagnosed by nocturnal respiratory polygraphy in geriatric inpatients.MethodWe conducted a retrospective, cross-sectional study in a sample of 102 geriatric inpatients from a French Geriatric University Hospital. We reviewed medical records to collect demographic, medical information including comorbidities, the geriatric cumulative illness rating scale (CIRS-G), subjective sleep-related symptoms and data of overnight level three portable sleep polygraphy recording.ResultsAmong classic OSA symptoms, only excessive daytime sleepiness (p = 0.02) and nocturnal choking (p = 0.03) were more prevalent in older inpatients with OSA (n = 64) than in those without (n = 38). The prevalence of comorbidities and mean CIRS-G scores were not different between groups except for the lower prevalence of chronic obstructive pulmonary disease and the higher level of creatinine clearance in OSA patients. Multivariate analysis showed OSA was associated with excessive daytime sleepiness (OR = 2.83, p = 0.02) in symptoms-related model and with composite CIRS-G score (OR 1.26, p = 0.04) in comorbidities-related model.ConclusionsOnly excessive daytime sleepiness and comorbidity severity (composite CIRS-G score) were associated with the objective diagnosis of OSA, while other usual clinical OSA symptoms and comorbidities in geriatric inpatients were not. These findings emphasize the importance of excessive daytime sleepiness symptom, when reported in comorbid older patients, strongly suggesting OSA and requiring adequate nocturnal exploration.     

Maintenance of wakefulness test: how does it predict accident risk in patients with sleep disorders?

Study ObjectiveTo determine whether the objective level of alertness measured by the Maintenance of Wakefulness Test (MWT) is associated with the occurrence of self-reported sleepiness-related traffic near misses and accidents related to sleepiness in patients with sleep disorders.MethodsThis case-control study was conducted over a three–year period in four French sleep centers during a 4140 min MWT in patients driving more than 5000 Km/year. Relationship between mean sleep latency on the MWT (MWT latency) and age, sex, driving, sleepiness-related near misses and accidents reported during the previous year, and sleep disorder characteristics was analyzed.ResultsOf 377 patients suffering from OSAS, idiopathic hypersomnia, narcolepsy, restless leg syndrome or insufficient sleep syndrome, 176 were included. 74 cases reported an accident or near miss related to sleepiness at the wheel in the past year, and 102 reported no accident/near miss (control patients). Thirty-one (37.8 %) cases and 9 (8.8 %) controls reported being sleepy at the wheel more than once a week (p < 0.0001). After adjusted regression analyses, patients with MWT latency between 19 and 33 minutes had a 3.2- (CI 95%[1.5; 6.8], p < 0.0001) fold increase in risk of reporting a near miss/ accident and patients with MWT latency <19 min had a 5.5- (CI 95%[2.2; 13.8], p = 0.003) fold increase in this risk, compared to the referent group (MWT latency>33 min).ConclusionsMWT latency is associated with self-reported, sleepiness-related near misses and accidents related to sleepiness in the past year in patients routinely investigated in sleep clinics. The MWT could be used to assess driving risk together with clinical interviews assessing sleepiness at the wheel.     

Excessive daytime sleepiness in obstructive sleep apnea: prevalence, severity, and predictors

OBJECTIVES: To assess prevalence, severity, and predictive factors of excessive daytime sleepiness (EDS) in obstructive sleep apnea (OSA) in an Asian population. METHODS: A retrospective, cross-sectional study of data from patients diagnosed with OSA over a period of three years and having had overnight polysomnography (PSG) followed by daytime multiple sleep latency test (MSLT). Respiratory disturbance index (RDI) was used for diagnosis and assessment of severity. OSA was classified as mild (RDI 5-20), moderate (RDI 20-40), and severe (RDI>40). EDS was objectively assessed using MSLT. According to MSLT, patients were categorized into two groups; EDS (mean sleep latency:MSL<10) and no EDS (MSL>10). PSG, MSLT and demographic data were subjected to univariate and multivariate analyses to ascertain predictive factors of EDS. RESULTS: There were 195 patients comprising 89.4% males and 10.6% females. The severity of OSA was mild in 35.9%, moderate in 27.2%, and severe in 36.9%. EDS was demonstrated in 87.2%. Sleep onset REM periods were detected in the MSLT of 28.2% patients. Univariate analysis demonstrated age, RDI, sleep efficiency, total arousals, arousals with apnea, arousal index, number of desaturations, and severity of snoring as significant predictors of EDS. However, stepwise logistic regression analysis identified only sleep efficiency, total arousals, and severity of snoring as significant predictive factors. CONCLUSIONS: OSA causes EDS in the majority of patients. Severe snoring, higher sleep efficiency and increased total arousals in polysomnography seem to predict EDS.     

Sleep positions in children with Down syndrome and obstructive sleep apnea

ObjectivesTo assess sleep positions in children with both Down syndrome (DS) and obstructive sleep apnea (OSA) and determine if there is a preferred sleep position by severity of apnea.MethodsA single-center retrospective review of patients with both DS and OSA was performed. Caregivers reported sleep position utilized greater than 50% of observed sleep time. Accuracy of this report was confirmed through review of hypnograms from polysomnography studies.ResultsEighty-two patients met inclusion criteria. Median body mass index (BMI) was 26.6 and 56% of patients had a prior tonsillectomy and/or adenoidectomy. The mean obstructive AHI (OAHI) was 25.33 with 90.4% having severe OSA, 9.6% having moderate OSA, and no patients having mild OSA. Reported sleep positions were skewed towards lateral/decubitus (82.9%) compared to prone (11.0%) and supine (6.1%). This was consistent with hypnogram data where 71% of total sleep time in lateral/decubitus positions compared to prone (13%) and supine (6%). The median changes in sleep position per patient was 5 (IQR: 3–6). Lower BMI (p < 0.001, 95% CI: 0.32–1.13) and tonsillectomy (p < 0.001, 95% CI: 7.7–18.19) were associated with lower OAHI. Sleep position was not associated with age (p = 0.19), sex (p = 0.66), race (p = 0.10), ethnicity (p = 0.68) nor history of tonsillectomy (p = 0.34). Preferred sleep position was not correlated with OAHI (p = 0.78, r = 0.03) or OSA severity (p = 0.72, r = 0.03).ConclusionsThis study highlights the possibility that children with DS may have preferential sleep positions that cater to optimized airflow in the context of OSA although further prospective study is needed.     

Assessment of multiple sleep latency testing in adults in Europe

Guidelines for the multiple sleep latency test (MSLT) were published in 1986 and updated in 2005. Individual interpretation of instructions may lead to variability in conducting and reporting the test with implications for diagnosis.ObjectiveTo assess variability in conducting MSLT among sleep laboratories in Europe.MethodsA questionnaire based on the clinical MSLT guidelines was posted or emailed to 283 sleep centres in Europe.ResultsNinety adult laboratories performing MSLT returned the questionnaire. Indications for MSLT were: narcolepsy, excessive daytime somnolence, driving issues and assessment of wakefulness. Routinely, only 17% of laboratories performed urinary drug screening and 68.2% asked patients to complete sleep diaries. Overnight polysomnography before MSLT was ran in 87.5% of laboratories. There was variation in setup and instructions among countries. Sleep onset was scored as one epoch of any stage sleep by 65.9% of labs. REM latency was calculated and reported according to the 2005 guidelines in 73.7% of cases. Abnormal daytime sleepiness was considered to be a sleep latency⩽5 min in 33% laboratories.ConclusionThere is marked variability in the practice and interpretation of the MSLT in Europe.     

Obstructive sleep apnea in narcolepsy

Study objectivesNarcolepsy and obstructive sleep apnea syndrome (OSAS) are two conditions associated with excessive daytime sleepiness (EDS). They may coexist in the same patient but the frequency of this association and its clinical significance is unknown. The presence of obstructive sleep apnea (OSA) in a narcoleptic patient may interfere with the diagnosis of narcolepsy. The aim of the study was to determine the prevalence of OSA in narcolepsy.Design and settingUniversity hospital sleep clinic series of narcoleptic patients diagnosed with nocturnal polysomnography and multiple sleep latency test. Patients were systematically interviewed evaluating narcoleptic and OSAS features and their response to continuous positive airway pressure (CPAP) treatment when applied.PatientsOne hundred and thirty-three patients with narcolepsy.ResultsThirty-three patients (24.8%) had an apnea–hypopnea index greater than 10 with a mean index of 28.5 ± 15.7. Ten of them were initially diagnosed only with OSAS and the diagnosis of narcolepsy was delayed 6.1 ± 7.8 years until being evaluated in our center for residual EDS after CPAP therapy. In the remaining 23 patients, narcolepsy and OSA were diagnosed simultaneously. Cataplexy occurred with similar frequency in both groups. EDS did not improve in 11 of the 14 patients who were treated with CPAP. The presence of OSA was associated with male gender, older age and higher body mass index.ConclusionsOSA occurs frequently in narcolepsy and may delay the diagnosis of narcolepsy by several years and interfere with its proper management. In patients with OSA, cataplexy should be actively looked for to exclude the presence of narcolepsy. Treatment with CPAP does not usually improve EDS in narcoleptics with OSA.     

Sleep manifestations,sleep architecture in children with Eosinophilic esophagitis presenting to a sleep clinic

Study objectivesTo describe sleep manifestations, polysomnographic (PSG) findings, and specific sleep disorders in children with Eosinophilic Esophagitis (EoE).MethodsThis retrospective study included children with EoE who were referred to sleep clinics. Clinical manifestations, PSG variables, and diagnosis of sleep disorders were analyzed. Sleep architecture of patients with EoE was compared to control subjects.ResultsIn sum, 81 children with EoE met the criteria for entry into the analysis with a mean age of 10.1 ± 4.4 years. Of those, 46 children (57%) presented in the sleep clinic with active EoE symptoms, while 35 (43%) children did not have active EoE symptoms at presentation. Several sleep complaints were common in children with EoE, including snoring (62, 76.5%), restless sleep (54, 66.6%), legs jerking or leg discomfort (35, 43.2%) and daytime sleepiness (47, 58.0%). Comparing sleep architecture with controls, children with EoE had significantly higher NREM2 (P= < 0.001), lower NREM3 (P= < 0.001), lower rapid eye movement (REM) (P = 0.017), increased periodic leg movements (PLM) index (P= < 0.001) and increased arousal index (P = 0.007). There were no significant differences in the sleep efficiency between the EoE and control subjects. Common sleep diagnoses included obstructive sleep apnea (OSA, 30, 37.0%) and periodic limb movements disorder (PLMD, 20, 24.6%). Of note, we found a much higher percentage of PLMD in active EoE compared to inactive EoE (P = 0.004).ConclusionsChildren with EoE have frequent sleep complaints and several sleep disorders identified from the sleep study, including sleep-disordered breathing and PLMD. Analysis of sleep architecture demonstrates significant sleep fragmentation as evidenced by decreased slow-wave sleep and REM sleep and increased arousal index.     

A six year-old case of narcolepsy

We report here a 6-year-old boy with narcolepsy. The diagnostic criteria were met by the clinical symptoms including excessive daytime sleepiness and cataplexy, and by the results of overnight polysomnography (PSG), multiple sleep latency test (MSLT), and human leukocyte antigen (HLA). PSG showed increased ratio of sleep stages 1 and 2 due to frequent awakening. All the five test session of MSLT showed a sleep onset REM period. HLA typing was positive for DRB1* 1501 and DQB1* 0602. Though the present case had very early onset, all the clinical symptoms and results of sleep studies met the criteria of narcolepsy. The CSF orexin level was far below the lower limit of the control values. It is very useful to measure CSF orexin for the diagnosis of early onset narcolepsy.     

Clinical significance of periodic limb movements during sleep: the HypnoLaus study

ObjectivePeriodic limb movements during sleep (PLMS) are prevalent in the general population, but their impact on sleep and association with cardiometabolic disorders are a matter of debate.MethodsData from 2162 participants (51.2% women, mean age 58.4 ± 11.1 years) of the population-based HypnoLaus study (Lausanne, Switzerland) were collected. Subjective sleep complaints and habits were assessed using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale (ESS). Participants underwent a full polysomnography (PSG) at home and were evaluated for the presence of hypertension, diabetes, and metabolic syndrome.ResultsParticipants with a PLMS index (PLMSI) > 15/h (28.6% of the sample) had longer subjective sleep latency (18.6 ± 17.2 vs. 16.1 ± 14.3 min, p = 0.014) and duration (7.1 ± 1.2 vs. 6.9 ± 1.1 h, p < 0.001) than participants with PLMSI ≤ 15/h. At the PSG, they spent more time in stage N2 sleep (49.0 ± 11.2 vs. 45.5 ± 9.8%, p < 0.001), less in stage N3 (17.6 ± 8.2 vs. 20.6 ± 8.4%, p < 0.001) and in REM sleep (20.3 ± 6.4 vs. 22.4 ± 6.0%, p < 0.001), and exhibited longer REM latency (104.2 ± 70.2 vs. 91.7 ± 58.6 min, p < 0.001) and higher arousal index (26.5 ± 12.3 vs. 19.2 ± 9.7 n/h, p < 0.001). Participants with a PLMSI > 15/h had a lower ESS scores and higher prevalence of hypertension, diabetes, and metabolic syndrome. Multivariate analysis adjusting for confounding factors confirmed the independent association of PLMSI > 15/h with subjective sleep latency and duration, and with objective sleep structure disturbances. However, the associations with sleepiness and cardiovascular risk factors disappeared.ConclusionsIn our large middle-age European population-based sample, PLMSI > 15/h was associated with subjective and objective sleep disturbances but not with sleepiness, hypertension, diabetes, or metabolic syndrome.