Sleep Medicine

Editorial Board

2010-02-01

Persistent sleep apnea is common and needs to be found

Marcel A. Baltzan, Norman Wolkove — 2010-02-01

Sleep apnea is a chronic disease that affects a significant proportion of the population at all ages . The great majority of scientific work about sleep apnea published in the past 25years examined the relationship of sleep apnea with various other health parameters before treatment. Many dealt with the methods of diagnosis, while others evaluated factors related to the institution of effective therapy in short term studies. Few studies have followed patients after long-term therapy. Yet throughout the world increasing numbers of people with obstructive sleep apnea (OSA) are being treated, usually with positive airway pressure (PAP). How to best care for these millions of patients is left to clinicians who often do not have clear and scientific therapeutic guidelines and whose experience and clinical acumen must then guide therapy over the following years for each patient.

Depressive disorders may more commonly be related to circadian phase delays rather than advances: Time will tell

Alfred J. Lewy — 2010-02-01

The generative phase advance hypothesis of affective disorders was formulated three decades ago. As the field has progressed, however, the evidence has generally not been confirmatory. Could it be that researchers have been looking in the wrong direction? The paper in this issue by Rahman and colleagues is the most recent to suggest that the most common circadian phase disturbance in depression may actually be a delay and not an advance.

Residual sleep apnea on polysomnography after 3 months of CPAP therapy: Clinical implications, predictors and patterns

2010-02-01

Abstract: Objective: We sought to determine the clinical implications, predictors and patterns of residual sleep apnea on continuous positive airway pressure (CPAP) treatment in patients with moderate-to-severe obstructive sleep apnea (OSA).Methods: We performed a post hoc secondary analysis of data from a previously reported randomized trial. Sleepy patients with a high risk of moderate-to-severe OSA identified by a diagnostic algorithm were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. We observed them for 3months and measured apnea–hypopnea index (AHI) on CPAP, Epworth sleepiness scale (ESS), sleep apnea quality of life index (SAQLI), CPAP pressure and objective CPAP compliance.Results: Sixty-one patients were randomized, 30 to the PSG group and 31 to the ambulatory group. Fifteen patients (25%) had residual sleep apnea (AHI>10/h on CPAP) with similar proportions in the PSG (7/30) and ambulatory (8/31) groups. Baseline variables including age, body mass index (BMI), ESS, SAQLI, respiratory disturbance index (RDI) and CPAP pressure did not differ between the groups. Outcomes including compliance were worse in patients with residual sleep apnea. Periodic breathing was prevalent among patients with residual sleep apnea.Conclusions: Residual sleep apnea is common in patients with moderate-to-severe OSA, despite careful CPAP titration, and is associated with worse outcomes.

Putative facilitators and barriers for adherence to CPAP treatment in patients with obstructive sleep apnea syndrome: A qualitative content analysis

2010-02-01

Abstract: Introduction: Effective treatment of obstructive sleep apnea syndrome (OSAS) with continuous positive airway pressure (CPAP) can reduce morbidity and mortality, but adherence rates are low without a clear consensus of causes.Objective: To explore the experiences of adherence to CPAP treatment in patients with OSAS.Methods: A qualitative content analysis was employed. Data were collected by in-depth interviews with 23 purposively selected patients.Results: Adherence to CPAP treatment was summarized according to “facilitators” and “barriers” to CPAP treatment. Facilitators for adherence, as described by the patients were a desire to avoid symptoms, knowledge about the risk for medical consequences, fear of negative social consequences and disturbing the sleep of significant others. Other facilitators were a positive attitude to CPAP treatment, trust in healthcare personnel, a sense of engagement from the spouse and a feeling of physical improvement. Barriers included experiencing practical problems, negative psychological effects of the equipment, and negative attitudes to the treatment. Other barriers were side-effects as well as insufficient support from healthcare personnel and the spouse.Conclusion: Adherence to CPAP treatment is a multifaceted problem including patient, treatment, condition, social and healthcare related factors. Knowledge about facilitators and barriers for adherence to CPAP treatment can be used in interventional strategies.

Antidepressant action of melatonin in the treatment of Delayed Sleep Phase Syndrome

Shadab A. Rahman, Leonid Kayumov, Colin M. Shapiro — 2010-02-01

Abstract: Background: Depression is a common problem in patients with Delayed Sleep Phase Syndrome (DSPS). This study used a randomized, double-blind, crossover, placebo-controlled approach to test the hypothesis that exogenous melatonin (5mg) can attenuate depressive symptomatology in DSPS patients.Methods: Twenty patients with an established diagnosis of DSPS were dichotomized into DSPS with depressive symptoms (Group I; n=8) and without depressive symptoms (Group II; n=12) based on structured clinical interviews and a score greater than 17 on Center for Epidemiologic Studies Depression Scale (CES-D). Both groups received melatonin and placebo treatment for 4weeks with a 1-week washout period in between. Participants underwent a clinical interview and psychometric evaluation to assess depression, and overnight polysomnographic sleep studies were carried out at baseline and at the end of melatonin and placebo treatments. Furthermore, melatonin secretion rhythm as a circadian phase marker was assessed by measuring urinary 6-sulphatoxymelatonin levels.Results: Melatonin treatment significantly reduced depression scores in the depressed patients as measured by the CES-D and Hamilton Depression Rating Scale – 17. Melatonin treatment improved sleep continuity in both groups compared to placebo and baseline conditions. Group I individuals showed marked alterations in melatonin rhythms compared to Group II individuals.Conclusion: Exogenous melatonin treatment may be an effective treatment modality for individuals with circadian rhythm sleep disorders and associated comorbid depressive symptomatology.

Cheyne–Stokes respiration in heart failure: Cycle length is dependent on left ventricular ejection fraction

2010-02-01

Abstract: Background: Cheyne–Stokes respiration (CSR) is common in patients with congestive heart failure (CHF) and is associated with poor prognosis. The aim of this study was to analyse the characteristics of CSR in patients with varying degrees of impaired left ventricular ejection fraction (LVEF).Methods: A total of 104 patients with CSR (apnea–hypopnea index [AHI]⩾15/h) and exertional dyspnea were divided into FIVE groups according to their LVEF (<20% upto ⩾50%). A subgroup of 22 patients was studied twice: 15 in whom LVEF improved between studies and 7 in whom LVEF deteriorated. Using cardiorespiratory polygraphy recordings, cycle length (CL), apnea length (AL), ventilation length (VL), time to peak ventilation (TTPV), circulatory delay (CD) and VL:AL ratio were determined.Results: There was no relationship between AHI and impairment of LVEF, but the characteristics of CSR were related to LV function. Comparing the groups with the best LVEF (>50%) and the worst LVEF (<20%), there were significant increases in CL (49±17–86±23s), AL (21±9–31±10s), VL (28±10–55±17s), TTPV (19±5–32±11s), VL:AL ratio (1.5±0.4–1.9±0.7s) and CD (29±8–49±16s). In the subgroup of patients who were studied twice, improvement in EF was associated with a decrease in these parameters.Conclusion: The current classification of CSR in CHF patients using AHI may be overly simplistic. Parameters such as CL, VL, TTPV and CD are related to cardiac function and could potentially be used for disease monitoring.

Impact of sleeping position on central sleep apnea/Cheyne–Stokes respiration in patients with heart failure

Shuji Joho, Yoshitaka Oda, Tadakazu Hirai, Hiroshi Inoue — 2010-02-01

Abstract: Background: The present study determines the influence of sleeping position on central sleep apnea (CSA) in patients with heart failure (HF).Methods: The apnea/hypopnea index (AHI) during different body positions while asleep was examined by cardiorespiratory polygraphy in 71 patients with HF (ejection fraction <45%).Results: Twenty-five of the patients having predominantly CSA (central apnea index ⩾10/h) with a lower obstructive apnea index (<5/h) were assigned to groups with positional (lateral to supine ratio of AHI <50%, n=12) or non-positional (ratio ⩾50%, n=13) CSA. In the non-positional group the BNP level was higher, the ejection fraction was lower and the trans-tricuspid pressure gradient was higher than in the positional group. Multiple regression analysis revealed more advanced age (p=0.006), log10BNP (p=0.017) and lung-to-finger circulation time (p=0.020) as independent factors of the degree of positional CSA. Intensive treatment for HF changed CSA from non-positional to positional in all eight patients tested. Single night of positional therapy reduced CSA (p<0.05) and BNP level (p=0.07) in seven positional patients.Conclusion: As cardiac dysfunction progresses, severity of CSA also increases and positional CSA becomes position-independent. Positional therapy could decrease CSA, thereby having a valuable effect on HF.

Sleep patterns in patients with acute coronary syndromes

2010-02-01

Abstract: Background: Little is known about sleep quality in patients with acute coronary syndromes (ACS) admitted to the coronary care unit (CCU). The aim of this study was to assess nocturnal sleep in these patients, away from the CCU environment, and to evaluate potential connections with the disease process.Methods: Twenty-two patients with first ever ACS, who were not on sedation or inotropes, underwent a full-night polysomnography (PSG) in our sleep disorders unit within 3days of the ACS and follow-up PSGs 1 and 6months later.Results: PSG parameters showed a progressive improvement over the study period. There was a statistically significant increase in total sleep time (TST), sleep efficiency, slow wave sleep (SWS), and rapid eye movement (REM) sleep, while arousal index, wake after sleep onset (WASO) and sleep latency decreased. Six months after the acute event, sleep architecture was within the normal range.Conclusions: Patients with ACS have marked alterations in sleep macro- and micro-architecture, which have a negative influence on sleep quality. The changes tend to disappear over time, suggesting a relationship with the acute phase of the underlying disease.

Reliability and validity of two self-administered questionnaires for screening restless legs syndrome in population-based studies

2010-02-01

Abstract: Background: A reliable and valid questionnaire for screening restless legs syndrome (RLS) is essential for determining accurate estimates of disease frequency. In a 2002 NIH-sponsored workshop, experts suggested three mandatory questions for identifying RLS in epidemiologic studies. We evaluated the reliability and validity of this RLS-NIH questionnaire in a community-based sample and concurrently developed and evaluated the utility of an expanded screening questionnaire, the RLS-EXP.Methods: The study was conducted at Kaiser Permanente of Northern California and the Stanford University Sleep Clinic. We evaluated test–retest reliability in a random sample of subjects with prior physician-assigned RLS (n=87), subjects with conditions frequently misclassified as RLS (n=31), and healthy subjects (n=9). Validity of both instruments was evaluated in a random sample of 32 subjects, and in-person examination by two RLS specialists was used as the gold standard.Results: For the first three RLS-NIH questions, the kappa statistic for test–retest reliability ranged from 0.5 to 1.0, and sensitivity and specificity was 86% and 45%, respectively. For the subset of five questions on RLS-EXP that encompassed cardinal features for diagnosing RLS, kappas were 0.4–0.8, and sensitivity and specificity were 81% and 73%, respectively.Conclusions: Sensitivity of RLS-NIH is good; however, the specificity of the instrument is poor when examined in a sample that over-represents subjects with conditions that are commonly misclassified as RLS. Specificity can be improved by including separate questions on cardinal features, as used in the RLS-EXP, and by including a few questions that identify RLS mimics, thereby reducing false positives.

Differential diagnosis of unpleasant sensations in the legs: Prevalence of restless legs syndrome in a primary care population

Caroline Möller, Thomas C. Wetter, Jürgen Köster, Karin Stiasny-Kolster — 2010-02-01

Abstract: Background: Restless legs syndrome (RLS) is a common neurological condition. We investigated the prevalence of RLS in patients suffering from unpleasant sensations in the legs.Methods: We included 16,543 patients consulting one of 312 primary care practices in Germany on November 8, 2007. All patients filled out a self-assessment questionnaire. Patients who reported suffering from unpleasant sensations in the legs were then assessed by the physician. Main outcome measures were the overall prevalence of unpleasant sensations in the legs and the prevalence of RLS; the most common differential diagnoses in the subpopulation suffered from unpleasant leg sensations.Results: Out of all participating patients 7704 (46.6%) suffered from unpleasant sensations in the legs and 1758 (10.6%) were diagnosed with RLS according to the four essential clinical criteria. Among patients with unpleasant leg sensations, the prevalence of RLS was considerably higher (22.7%) than in the total population. The most common differential diagnoses were osteoarthritis (21.5%), disc lesion (19.2%), varicose veins (18.8%) and muscle cramps (14.6%). Of the patients with RLS 53.4% had already consulted their physician about their leg problems in the past. Still, only 20.1% of the RLS patients had received the correct diagnosis. Comorbidity rates were significantly increased in RLS patients compared to patients suffering from leg symptoms of other origin.Conclusions: This study showed a high prevalence of RLS in primary care patients with unpleasant sensations in the legs. Thus, in patients presenting with these symptoms the diagnosis of RLS should routinely be considered.

REM sleep behavior disorder in 703 sleep-disorder patients: The importance of eliciting a comprehensive sleep history

2010-02-01

Abstract: Objectives: The aim of our study was to evaluate the frequency of REM sleep behavior disorder (RBD) in a mixed sleep laboratory population and to assess potential associations. Moreover, we investigated referral diagnoses of patients subsequently diagnosed with RBD and assessed the frequency of incidental RBD.Methods: Charts and polysomnographic reports of 703 consecutive patients comprising the full spectrum of ICSD-2 sleep disorders [501 males, 202 females; mean age, 51.0±14.1years (range: 10–82years)] were carefully reviewed. The vast majority of patients were adults (98.7%). Patients were categorized into those with and without RBD. For associations, all concomitant sleep and neurological diagnoses and medications were evaluated.Results: Thirty-four patients (4.8%) were diagnosed with RBD (27 men; 7 women, mean age, 57.7±12.3years). RBD was idiopathic in 11 patients (1.6%; 9 men) and symptomatic in 23 patients (3.3%; 18 men) secondary to Parkinsonian syndromes (n=11), use of antidepressants (n=7), narcolepsy with cataplexy (n=4), and pontine infarction (n=1). Six out of 34 patients were referred for suspected RBD, 20 reported RBD symptoms only on specific questioning, and 8 patients had no history of RBD but showed typical RBD behavioral manifestations in the video-polysomnography. Logistic regression analysis revealed significant associations between RBD and the presence of Parkinsonian syndromes (odds ratio [OR] 16.8, 95%CI: 6.4–44.1; P<0.001), narcolepsy with cataplexy (OR 10.7, 95%CI: 2.9–40.2; P<0.001), SSRI use (OR 3.9, 95%CI: 1.6–9.8; P=0.003), and age (OR 1.5/10-year increase, 95%CI: 1.0–2.0; P=0.039).Conclusion: In this population of 703 consecutive sleep-disorder patients, RBD was uncommon. Its etiology was predominantly symptomatic. The majority of RBD patients reported RBD symptoms on specific questioning only, underlining the importance of eliciting a comprehensive sleep history for the diagnosis of RBD.

REM sleep characteristics of nightmare sufferers before and after REM sleep deprivation

2010-02-01

Abstract: Objectives: To examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology.Background: Heightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dreamlike quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs.Methods: A preliminary study of 14 subjects with frequent NMs (⩾1NM/week; 27.6±9.9years) and 11 healthy control subjects (<1NM/month; 24.3±5.3years) was undertaken. Subjects completed home sleep/dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3.Results: Several measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density, REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study.Conclusions: Findings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity.

Relationships among dietary nutrients and subjective sleep, objective sleep, and napping in women

Michael A. Grandner, Daniel F. Kripke, Nirinjini Naidoo, Robert D. Langer — 2010-02-01

Abstract: Objective: To describe which dietary nutrient variables are related to subjective and objective habitual sleep and subjective and objective napping.Methods: Participants were 459 post-menopausal women enrolled in the Women’s Health Initiative. Objective sleep was estimated using one week of actigraphy. Subjective sleep was prospectively estimated with a daily sleep diary. Dietary nutrients were calculated from food frequency questionnaires.Results: The most significant correlations were with subjective napping, including (from strongest to weakest): total fat, calories, saturated fat, monounsaturated fat, trans fat, water, proline, serine, tyrosine, phenylalanine, valine, cholesterol, leucine, glutamic acid, ash, isoleucine, histidine, sodium, tryptophan, protein, threonine, cystine, methionine, phosphorous, polyunsaturated fat, animal protein, aspartic acid, arginine, lysine, alanine, caffeine, riboflavin, gamma-tocopherol, glycine, retinol, delta-tocopherol, Vitamin D, and selenium. Actigraphic nocturnal sleep duration was negatively associated with total fat, monounsaturated fat, trans fat, saturated fat, polyunsaturated fat, calories, gamma-tocopherol, cholesterol, and alpha-tocopherol-eq.Conclusions: Actigraphic total sleep time was negatively associated with intake of fats. Subjective napping, which may be a proxy for subjective sleepiness, was significantly related to fat intake as well as intake of meat.

Subjective and objective sleep and sleepiness among tunnel workers in an extreme and isolated environment: 10-h shifts, 21-day working period, at 78 degrees north

Knut Forberg, Siri Waage, Bente Moen, Bjørn Bjorvatn — 2010-02-01

Abstract: Objectives: The aim of this study was to examine the effects of extended work hours (10h on, 14h off for 21days) on sleep and sleepiness in an extreme and isolated environment in the far north (Spitsbergen, 78 degrees north). We wanted to examine whether sleep duration, sleepiness and other parameters changed over the 3-week working period and whether the parameters differed between day and night shifts.Methods: The work consisted of tunnel construction in Svea, Spitsbergen. The participants worked alternate fixed day shift (06:00–16:00) or fixed night shift (18:00–04:00) for a 21-day work period in a counterbalanced, crossover design. The participants were 25 male workers (age 24–60years). We used subjective and objective measures of sleep (diary and actigraphy) and a subjective daytime sleepiness and function questionnaire.Results: The workers had a high sleep efficiency measured both subjectively and objectively. This did not change across days or between day and night shifts. Total sleep time was significantly shorter (about ½ to 1h) during the day shift period than during the night shift period, as measured both subjectively and objectively, but did not differ across days. Subjective ratings of sleepiness did not differ between shifts.Conclusions: There were few differences between the day and night shift periods and across the 21-day working period, as measured both subjectively and objectively. The subjects experienced few problems and seemed to adapt easily to their work schedule. This contrasts with what is usually the case in more conventional shift work situations, where workers do not adapt well, as measured by sleepiness and various sleep parameters.

Invalidity of one actigraphy brand for identifying sleep and wake among infants

Salvatore P. Insana, David Gozal, Hawley E. Montgomery-Downs — 2010-02-01

Abstract: Study objectives: Few commercially available brands of actigraphs (ACT) have been subjected to rigorous validation with infant participants. The purpose of this study was to examine the agreement between concurrent polysomnography (PSG) and one brand of ACT (AW-64, Mitter Co. Inc.) using appropriate statistical techniques among a sample of healthy infants.Methods: Twenty-two healthy infants (14.1±0.6months) had one night of ankle ACT recording during research PSG at Kosair Children’s Hospital Sleep Research Center in Louisville, Kentucky. Macroanalyses were conducted using the Bland–Altman concordance technique to assess agreement between total sleep time (TST) and wake after sleep onset (WASO) simultaneously measured by PSG and ACT, using two ACT algorithm settings. Microanalyses were also calculated to examine sensitivity, specificity, and accuracy of ACT within each PSG-identified sleep state. Correlations were calculated between PSG-identified arousals and the discrepancies between ACT and PSG.Results: The Bland–Altman concordance technique revealed that ACT underestimated TST by 72.25 (SD=61.48) minutes and by ⩾60min among 54.55% of infants. Furthermore, ACT overestimated WASO by 13.85 (SD=30.94) minutes and by ⩾30min among 40.91% of infants. Sensitivity, specificity, and accuracy analyses revealed that ACT adequately identified sleep, but poorly identified wake. PSG and ACT discrepancies were positively associated with PSG-identified arousals (r=.45).Conclusions: Improved device and/or software development is needed before the AW-64 can be considered a valid method for identifying infant sleep and wake.

Increased risk of snoring and adenotonsillectomy in children referred for tympanostomy tube insertion

Riva Tauman, Ari DeRowe, Orna Ophir, Michal Greenfeld, Yakov Sivan — 2010-02-01

Abstract: Objective: Eustachian tube dysfunction and sleep-disordered breathing (SDB) share common pathophysiologic mechanisms. Our objective was to investigate whether children referred for isolated TTI (tympanostomy tube insertion) are at increased risk for snoring and upper airway procedures.Methods: Telephone interviews to parents of children who underwent isolated TTI and to age- and gender-matched controls were conducted.Results: Four hundred fifty-seven children were included in the study; 352 had isolated TTI (study group) and 105 children were controls. Twenty-two percent of children in the study group were reported to snore compared with 7.6% in the controls (p=0.001). Eighteen percent of children in the study group were reported to have undergone adenotonsillectomy compared with 4.8% in the controls (p=0.0005). Future SDB, i.e., either snoring or adenotonsillectomy following TTI, was found in 34% of children in the study group compared with 11% in the controls (p=0.0004). Children who underwent isolated TTI were at increased risk for future snoring (OR=3.4, CI: 1.6–7.2) and future adenotonsillectomy (OR=4.4, CI: 1.7–11.2).Conclusions: Children who undergo isolated TTI are at increased risk for snoring and for adenotonsillectomy. We suggest that these children be followed for symptoms of SDB on a scheduled basis to allow for early diagnosis and intervention.

The effect of long term ventilatory support on hemodynamics in children with spinal muscle atrophy (SMA) type II

Agneta Markström, Gary Cohen, Miriam Katz-Salamon — 2010-02-01

Abstract: Background: Bi-level Positive Airway Pressure (Bi-PAP) treatment improves breathing efficiency and ventilation in children with SMA type II, but the effects of positive airway pressure swings on heart rate (HR) and blood pressure are not known. Here we studied children with SMA to determine whether Bi-PAP administered during sleep is associated with changes in hemodynamics.Methods: Ten children aged 8–12years on long term Bi-PAP therapy were evaluated during a routine overnight sleep study. We recorded HR, ECG, thoraco-abdominal movements and blood gases. Blood pressure was estimated indirectly from pulse transit time (PTT) and the efficiency (“work”) of breathing from the phase angle between chest and abdominal movements. We compared periods of unsupported (spontaneous) and supported (i.e., on Bi-PAP) breathing during a split-night study. We also compared periods when Bi-PAP was judged optimal with periods that were sub-optimal due to mask leakage.Results: HR and PTT during unsupported breathing and on optimal Bi-PAP were comparable (p=0.85 and 0.79, respectively), as were blood gases (SaO2, TcO2, TcCO2 p=0.79, 0.88, 0.79, respectively). Breathing efficiency improved as expected when Bi-PAP was optimal (decrease in phase angle from 42° to 22°). Sub-optimal Bi-PAP due to air leaking from the mask was associated with marked increases in breath-to-breath variability of HR, PTT and phase angle.Conclusions: Bi-PAP therapy does not appear to adversely influence hemodynamics in children with SMA if pressures are optimized and the mask is correctly applied and sealed.

Apocynin attenuate spatial learning deficits and oxidative responses to intermittent hypoxia

Liu Hui-guo, Liu Kui, Zhou Yan-ning, Xu Yong-jian — 2010-02-01

Abstract: Rationale: The long-term intermittent hypoxia (LTIH) that characterizes sleep-disordered breathing impairs spatial learning and increases oxidative stress in rodents. We hypothesized that LTIH activated brain NADPH oxidase, which served as a critical source of superoxide in the oxidation injury, and that apocynin might attenuate LTIH-induced spatial learning deficits by reducing LTIH-induced NADPH oxidase expression. Objective: To investigate the effects of apocynin on spatial learning and oxidative responses to LTIH in rats. Methods: Forty healthy male Sprague–Dawley (SD) rats were randomly divided into four groups of 10 each: a LTIH group, an apocynin-treated LTIH group, a sham LTIH group and an apocynin-treated sham group. Spatial learning in each group was assessed with the Morris water maze test. RT-PCR and Western blot were used to examine mRNA and protein expression of NADPH oxidase subunit p47phox and p22phox in the hippocampus region. The level of MDA and SOD were detected by colorimetric method. The terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) method was used to display the apoptotic cells of the hippocampus tissue. Results: Apocynin treatment prevented LTIH-induced decreases in spatial learning during the Morris water maze as well as LTIH-induced decrease in SOD levels. In untreated animals, LTIH exposure was related to increase of MDA levels in comparison to sham LTIH animals, and apocynin-treated animal exposure to LTIH showed reduction in MDA levels. Increases in hippocampus NADPH oxidase subunit p47phox mRNA and protein expression were observed in LTIH-exposed animals; there was no statistical difference of p47phox mRNA and protein expression between LTIH group and apocynin treatment group. Treatment with apocynin significantly ameliorated cell apoptosis in LTIH-exposed animals. Conclusion: These results indicate that apocynin attenuates LTIH-induced spatial learning deficits and mitigates LTIH-induced oxidative stress through multiple beneficial effects on oxidant pathways. NADPH oxidase up-expression is closely associated with oxidative processes in LTIH rats, and inhibition of NADPH oxidase activity may hopefully serve as a useful strategy for cognitive function impairment from chronic intermittent hypoxia.

Genetic polymorphisms in endothelin-receptor-subtype-a-gene as susceptibility factor for obstructive sleep apnea syndrome

2010-02-01

Abstract: Introduction: Traits of obstructive sleep apnea syndrome (OSAS) such as impaired ventilatory control, craniofacial abnormalities, and concomitant cardiovascular diseases are associated with modified endothelin-1 gene (EDN-1) or endothelin-receptor-subtype-a (EDNRA) gene. The endothelin system regulates the cardiovascular homeostasis. EDN-1 interacts mainly with EDNRA for signal transduction. In our study we investigate associations of EDNRA-polymorphisms (four frequent polymorphisms with an allele frequency >5%) and OSAS severity.Methods: Three hundred ninety-three patients older than 18years, of Caucasian origin and with OSAS (AHI>5/h and daytime sleepiness) were investigated by cardiorespiratory polysomnography. In addition 58 control subjects with healthy sleep were recruited from nearly 300 volunteers. We analysed the EDNRA-polymorphisms E335E, H323H, G-231A and G+70C by polymerase-chain-reaction, restriction-fragment-length-polymorphism and real-time-PCR.Results: Carrier of the mutant G-231A allele had a significantly lower AHI (p=0.03, OR 0.53, 95% CI 0.3–0.94) when comparing patients and controls. When comparing OSAS severity groups without controls we could not detect significant correlations for the four investigated EDNRA-polymorphisms. Our data confirm that BMI (p<0.001) and male gender (p=0.02) are significantly associated with AHI. The allele frequencies were similar.Discussion: The genetic investigation of OSA remains important. Our control group was relatively small and we investigated 4 reasonable candidates out of more than 100 EDNRA-polymorphisms. The detected protective effect of the mutant G-231A allele needs further confirmation. Gene based research in OSAS should use genome wide scan and should still consider the endothelin system.

Increased prevalence of nocturnal smoking in restless legs syndrome (RLS)

2010-02-01

Abstract: Objective: We investigated the prevalence of nocturnal smoking (NS) in patients with RLS.Methods: One hundred RLS patients living in Emilia-Romagna (Northern Italy) and 100 matched controls, randomly selected from the general population, underwent interviews for the presence of nocturnal smoking and for obsessive-compulsive traits, depression, excessive daytime sleepiness (EDS) and subjective sleep quality.Results: NS was more prevalent in RLS patients than controls (lifetime prevalence: 12% vs. 2%, P=0.012). Patients with NS had more frequently Sleep-Related Eating Disorders (SRED) than patients without NS (83.3% vs. 26.1%, P=0.0002). Pathological and borderline Maudsley Obsessive-Compulsive Inventory (MOCI) values as well as pathological values at the Beck Depression Inventory (BDI) increased from controls to RLS patients without NS to RLS patients with NS (P=0.005 and P=0.01, respectively).Conclusions: We demonstrate an increased prevalence of NS in patients with RLS, in many cases associated with increased SRED. NS may be associated with psychopathological traits in RLS and may be relevant in the management of RLS patients.

Introduction to Video-Clinical Corners

2010-02-01

Cyclic alternating pattern (CAP)-related cough and sleep-related laryngospam

2010-02-01

Sleep-related laryngospasm is a rare condition that refers to episodic arousal from sleep for breathing difficulties associated with feelings of suffocation, fear, coughing, tachycardia and stridor.

A case of resolution of amenorrhea after CPAP therapy for obstructive sleep apnea

Bijal Kirit Mehta, Nicolas Saikali, Marc Schlegel, Daniel Rifkin — 2010-02-01

We present a case of a 47-year-old Caucasian woman who reported symptoms of snoring, excessive daytime sleepiness, and witnessed apneas. She also had frequent nocturnal diaphoresis, which she attributed to the onset of possible menopause.

Obstructive sleep apnea as a cause of nocturnal eating

Alexey Amchentsev, Navatha Kurugundla, Gerard Lombardo — 2010-02-01

Sleep-related eating disorder (SRED) and nocturnal eating syndrome are part of the nocturnal eating disorders . Surprisingly, there are few patients described with OSA and concurrent sleep-related eating, despite the common occurrence of nocturnal eating and consequent obesity . Our patient is a 65-year-old morbidly obese white female with chronic obstructive pulmonary disease (COPD) and asthma who presented with complaints of daytime somnolence, tiredness and a 14–18kg weight gain. Her roommate witnessed intermittent heavy snoring, which was frequently terminated by gasping. Many of these awakenings were associated with sleepwalking to the kitchen and gorging herself on food. She would then return to bed and fall asleep, with no recollection of nocturnal eating. Gastric bypass surgery did not change the nocturnal eating habits or weight gain.

Neuroimaging in narcolepsy

A. Bican, İ. Bora, O. Algın, B. Hakyemez, V. Özkol, E. Alper — 2010-02-01

To the Editor Narcolepsy is mostly an idiopathic disease, and clinical findings are used in diagnosing narcolepsy. There is no gold standard test for the diagnosis of narcolepsy , and the diagnostic criteria include clinical, polysomnogram, multiple sleep latency test, and measurement of hypocretin level in cerebrospinal fluid (an invasive method). A limited number of studies including Magnetic Resonance Imaging (MRI), Magnetic Resonance Spectroscopy (MRS) and Single Photon Emission Computed Tomography (SPECT) are reported in the literature with inconsistent results .

Erratum to “Epidemiological and clinical relevance of insomnia diagnosis algorithms according to the DSM-IV and the International Classification of Sleep Disorders (ICSD)” [Sleep Med 10 (2009) 952–960]

Maurice M. Ohayon, Charles F. Reynolds — 2010-02-01

The publishers regret that errors occurred in of the above printed article. The correct tables appear below.