Sleep Technician Research Articles

Psychiatric Disorder Does Not Preclude Adequate Continuous Positive Airway Pressure Titration

Obstructive sleep apnea (OSA) is a highly prevalent disorder associated with significant morbidity and multiple complications. A large proportion of patients with OSA also have a coexisting primary psychiatric disorder. The effect of psychiatric disorders on the ability to tolerate continuous positive airway pressure (CPAP) titration is not known. In this study, whether the presence of psychiatric disorders precludes the patients’ ability to tolerate CPAP titration for OSA was investigated. A retrospective chart review on a sample of 284 patients who underwent sleep studies in a single-center, university-based Veterans Affairs hospital was performed. A total of 143 patients with OSA who underwent titration of CPAP therapy were identified. The prevalence of psychiatric disorders between patients who tolerated titration and those who did not tolerate it was compared using the χ2 test. The percentages of patients with psychiatric disorders who tolerated and did not tolerate CPAP were 33.6% and 33.3%, respectively. No statistically significant difference between the 2 groups (χ2=0.051 with 1 degree of freedom; P=0.82) was found. The predominantly male patient population, exclusion of mild OSA, lack of data about the level of control of the psychiatric symptoms and the sleep technicians not being blinded to the patients’ psychiatric diagnoses were some of the limitations of this study. No significant difference existed in the prevalence of psychiatric disorders between patients intolerant to CPAP titration and those who tolerated CPAP for OSA.

Coherence Validation of Alternative Sleep EEG Electrode Placements Using Wavelet Transform

Recent studies on automated sleep stage classification have started to adopt alternative sleep encephalography (EEG) electrode placements on the forehead as opposed to the traditional C3-C4 placement. The current study determines the validity of adopting the prefrontal EEG electrode placement. First, EEG signals were decomposed into four harmonic bands using the discrete wavelet transform and their power spectrum densities were extracted for comparison. The correlation coefficients of both signals were calculated and jackknifed to determine an unbiased statistical value. The signal and its power spectrum displayed moderate to very strong values of the correlation coefficient, respectively, with minute standard errors and biases. A strong coherence is exhibited between both electrode placements as viewed from the power spectra of different sleep stages. The magnitude-squared coherence values indicate that the reduction in the coefficient values for the beta band was due to a low correlation in a certain frequency band. Manual sleep stage classification was also conducted by a sleep technician and sleep stage classification software, with consistent results obtained. Sleep stage scoring using both methods indicated substantial agreement for the standard and alternative electrode placements. In conclusion, this work shows a strong coherence for the prefrontal and standard electrode placements and corroborates the hypothesis of using the alternative placements for performing quick, convenient, and efficient measurement and analysis of EEG signals.

An open letter to the sleep and circadian rhythms community: Presidents’ viewpoints of the World Sleep Federation (WSF)

An open letter to the sleep and circadian rhythms community: Presidents’ viewpoints of the <scp>W</scp>orld <scp>S</scp>leep <scp>F</scp>ederation (<scp>WSF</scp>)

Global and local actions in the sleep domain: the ESRS perspective

As an active and long-standing member of the World Sleep Federation (WSF), the European Sleep Research Society (ESRS) is pleased to support the open letter written by the current and immediate past WSF presidents, published today in the Journal of Sleep Research, the official journal of the ESRS. In this letter, the WSF presidents encourage us to act both locally and globally in the sleep domain, learn from each other and share existing resources. In particular, they call for increased sleep education and training opportunities throughout the world, including certification programmes for sleep specialists and technicians, especially for those individuals living in developing countries. We agree wholeheartedly with such goals, and believe that existing education and training initiatives that have been developed by the ESRS at the European level can contribute significantly to this, while at the same time avoiding any overlap between the ESRS and WSF initiatives. Indeed, the ESRS is currently involved actively in the development of sleep medicine throughout Europe and is developing certification and training opportunities, especially in European countries where sleep is not yet an acknowledged speciality. In this respect, we recently organized the first European Examination in Sleep Medicine at the ESRS conference (Paris, September 2012). The examination was taken successfully by 50 selected international sleep experts, who received the certification: ‘ESRS Somnologist–Expert in Sleep Medicine’. This grandparenting initiative will be repeated at the forthcoming ERS–ESRS Sleep and Breathing Conference (Berlin, April 2013). This will lead to the constitution of an international body of certified sleep experts able to take the lead in future national and international activities to promote sleep medicine professionals. The certification process will also lead to the organization of the first open examination to all sleep professionals at the 2014 ESRS Congress in Tallinn, Estonia. In association with certification, coordinated and unified educational training initiatives also have to be taken, including publication of guidelines [as already published in the Journal of Sleep Research (Fischer et al., 2012; Pevernagie et al., 2006, 2009)] and textbooks in sleep medicine. In this respect, the ESRS believes that the future of sleep research and sleep medicine in Europe necessitates the creation and development of academic multi-disciplinary sleep centres across Europe (Bassetti et al., 2012). This will promote the integration of clinical and basic sleep science, and constitute a basis for the education and training of sleep experts, as advocated in the ESRS 40th anniversary book (Bassetti et al., 2012). We also believe that definition and publication of common guidelines between the WSF and ESRS would be an extremely useful accomplishment that is achievable through fruitful collaboration. These are only a few of the many ways in which we can develop sleep medicine and sleep research throughout Europe and the world, and we commend the WSF's initiative to establish special interest groups in key areas such as sleep genetics, insomnia and sleep and breathing. Similarly, the ESRS promotes sleep networks aimed at gathering both clinical and basic sleep researchers around key topics such as insomnia, sleep apnoea, narcolepsy and restless legs syndrome. We also believe that the existing sleep networks must communicate globally at all levels, and not be limited to specific regions. We would be happy to see the special interest groups and networks initiated by WFS and ESRS share common interests and experience, while bearing in mind that appropriate actions are needed both locally and globally, ranging from national to European and world levels. In conclusion, the ESRS warmly welcomes the initiative of the Presidents of the WSF. The ESRS will be happy to contribute to all the initiatives facilitating sleep training and research to make sleep a stronger and more unified field. This will greatly benefit the development of sleep science, as well as the care of those many patients suffering from recognized, but also too often unrecognized, sleep disorders.

Detection of Sleep Disordered Breathing and Its Central/Obstructive Character Using Nasal Cannula and Finger Pulse Oximeter

To assess the accuracy of novel algorithms using an oximeter-based finger plethysmographic signal in combination with a nasal cannula for the detection and differentiation of central and obstructive apneas. The validity of single pulse oximetry to detect respiratory disturbance events was also studied. Patients recruited from four sleep laboratories underwent an ambulatory overnight cardiorespiratory polygraphy recording. The nasal flow and photoplethysmographic signals of the recording were analyzed by automated algorithms. The apnea hypopnea index (AHI(auto)) was calculated using both signals, and a respiratory disturbance index (RDI(auto)) was calculated from photoplethysmography alone. Apnea events were classified into obstructive and central types using the oximeter derived pulse wave signal and compared with manual scoring. Sixty-six subjects (42 males, age 54 ± 14 yrs, body mass index 28.5 ± 5.9 kg/m(2)) were included in the analysis. AHI(manual) (19.4 ± 18.5 events/h) correlated highly significantly with AHI(auto) (19.9 ± 16.5 events/h) and RDI(auto) (20.4 ± 17.2 events/h); the correlation coefficients were r = 0.94 and 0.95, respectively (p < 0.001) with a mean difference of -0.5 ± 6.6 and -1.0 ± 6.1 events/h. The automatic analysis of AHI(auto) and RDI(auto) detected sleep apnea (cutoff AHI(manual) ≥ 15 events/h) with a sensitivity/specificity of 0.90/0.97 and 0.86/0.94, respectively. The automated obstructive/central apnea indices correlated closely with manually scoring (r = 0.87 and 0.95, p < 0.001) with mean difference of -4.3 ± 7.9 and 0.3 ± 1.5 events/h, respectively. Automatic analysis based on routine pulse oximetry alone may be used to detect sleep disordered breathing with accuracy. In addition, the combination of photoplethysmographic signals with a nasal flow signal provides an accurate distinction between obstructive and central apneic events during sleep.

Neurophysiological Two-Channel Polysomnographic Device in the Diagnosis of Sleep Apnea

Our objective was to evaluate a portable device (Somté, Compumedics, Australia), which incorporates 2 neurophysiological channels (electroencephalography and electrooculography) with cardiorespiratory monitoring for the diagnosis of obstructive sleep apnea (OSA). Full polysomnography (PSG) and Somté recordings were simultaneously performed in 68 patients with suspected OSA. Data were analyzed blindly by 2 scorers. A good agreement between methods in sleep efficiency was observed (68.8% [18.4] with PSG vs 68% [19.1] with Somté [p: n.s.] for scorer 1, and 67.5% [19.1] vs 68.4% [18.5; p: n.s.] for scorer 2). The apnea-hypopnea index (AHI) obtained with Somté was lower than with PSG: 19 (17.8) vs 21.7 (19) (p < 0.001) for scorer 1, and 16.6 (16.7) vs 20 (18.8) (p < 0.001) for scorer 2. The sensitivity of Somté for a PSG-AHI > 5 was 91% for scorer 1 and 90% for scorer 2, while specificity was 77% and 90%, respectively. The areas under the receiver operating curve for different PSG-AHI cutoff points (≥ 5, ≥ 15, and ≥ 30) were 0.81, 0.90, and 0.86, respectively, for scorer 1, and 0.90, 0.88, and 0.83 for scorer 2. These data suggest that Somté is an effective device to identify sleep and respiratory variables in patients with suspected OSA.

SOMNUS: A Sleep-Measuring Shirt Based on Chest Expansion and Respiratory Patterns

This paper presents a shirt embedded with simple capacitive sensors that accurately monitors the respiration of a sleeping person through chest expansion. It will also discuss a software package that, when coupled with this device, can determine sleep stages from the acquired data. Current sleep studies are the only medically accepted form of sleep health detection and diagnosis; due to the relatively high price of these studies, only persons with breathing-related disorders are referred to them. These studies depend on polysomnography, the use of various bodily signals for sleep detection; patients are often connected to over 20 sensors ranging from brain wave electrodes to blood oxygen trackers. The Somnus shirt is a comfortable, low-cost solution that could be used in the patient’s regular sleep setting. Through some preliminary testing, our respiration-monitoring prototype was able to produce respiration data similar to that of sensors employed in current sleep laboratories while achieving a higher level of comfort for the user; also, the software package was able to analyze sleep with accuracy comparable to current sleep laboratory technicians.

Automatic breath-to-breath analysis of nocturnal polysomnographic recordings

Diagnosis of sleep-disordered breathing is based on the presence of an abnormal breathing pattern during sleep. In this study, an algorithm was developed for the offline breath-to-breath analysis of the nocturnal respiratory recordings. For that purpose, respiratory signals (nasal airway pressure, thoracic and abdominal movements) were divided into half waves using period amplitude analysis. Individual breaths were characterized by the parameters of the half waves (duration, amplitude, and slope). These values can be used to discriminate between normal and abnormal breaths. This algorithm was applied to six polysomnographic recordings to distinguish abnormal breathing events (apneas and hypopneas). The algorithm was robust for the identification of breaths (sensitivity=96.8%, positive prediction value (PPV)=99.5%). The detection of apneas and hypopneas was compared to the manual scoring of two experienced sleep technicians: sensitivity was, respectively, 89.2 and 88.9%, PPV was 54.1 and 59.3%. The classification of apneas into central, obstructive, or mixed was in concordance with the observers in 68% of the apneas. Although the algorithm tended to detect more hypopneas than the clinical standard, this study shows that the extraction of breath-to-breath parameters is useful for detection of abnormal respiratory events and provides a basis for further characterization of these events.

Sleep efficiency during sleep studies: results of a prospective study comparing home-based and in-hospital polysomnography

To date, the clinical use of unattended home-based polysomnography (PSG) is not recommended. To assess whether sleep efficiency is better at home, we have performed a prospective, crossover, single-blind study comparing unattended home- versus attended in-hospital PSG in a population referred for high clinical suspicion of obstructive sleep apnoea syndrome (OSA). Within 2 weeks, all the patients underwent both PSG performed by the same sleep technician, which were analysed by another blinded technician. Payments for each procedure were also calculated. Sixty-six patients (mean age: 49±13 years; mean body mass index: 30±7; mean Epworth Sleepiness Scale: 10±5) were included. The quality of recordings was poor in 1.5% of the attended PSG versus 4.7% for unattended PSG (P=0.36). Sleep efficiency at home was better (82% versus 75%, P<0.001), and sleep duration longer (412 min versus 365 min, P<0.001). Sleep latency was also shorter at home (28 min versus 45 min, P=0.004), and patients spent more time in rapid eye movement sleep (19% versus 16%, P=0.006). Apnoea-hypopnoea index (23 versus 26, P=0.08) was similar at home and in the sleep lab. Sixty-seven per cent of patients preferred home-based PSG. PSG payment was also lower at home (268 Euros versus 1057 Euros). We conclude that home-based PSG is associated with a better sleep efficiency. It also appears as feasible and reliable in patients with high preclinical suspicion for OSA. It is also more comfortable for the patients whose sleep efficiency is better and allows cost saving related to the absence of hospitalization.

Objective measure of sleepiness and sleep latency via bispectrum analysis of EEG

Chronic sleepiness is a common symptom in the sleep disorders, such as, Obstructive Sleep Apnea, Periodic leg movement disorder, narcolepsy, etc. It affects 8% of the adult population and is associated with significant morbidity and increased risk to individual and society. MSLT and MWT are the existing tests for measuring sleepiness. Sleep Latency (SL) is the main measures of sleepiness computed in these tests. These are the laboratory-based tests and require services of an expert sleep technician. There are no tests available to detect inadvertent sleep onset in real time and which can be performed in any professional work environment to measure sleepiness level. In this article, we propose a fully automated, objective sleepiness analysis technique based on the single channel of EEG. The method uses a one-dimensional slice of the EEG Bispectrum representing a nonlinear transformation of the underlying EEG generator to compute a novel index called Sleepiness Index. The SL is then computed from the SI. Working on the patient's database of 42 subjects we computed SI and estimated SL. A strong significant correlation (r ≥ 0.70, s < 0.001) was found between technician scored SL and that computed via SI. The proposed technology holds promise in the automation of the MSLT and MWT tests. It can also be developed into a sleep management system, wherein the SI is incorporated into a sleepiness index alert unit to alarm the user when sleepiness level crosses the predetermined threshold.

Perioperative practical experiences in using a level 2 portable polysomnography

The objective of the study is to test the hypothesis that a level 2 portable sleep device (Embletta X100) is a reliable alternative for standard PSG in surgical patients. After hospital ethics approvals, preoperative patients over 18 years old were recruited. The patients for validation underwent standard PSG and Embletta X100 simultaneously in a sleep laboratory before surgery. The other patients received sleep studies with Embletta X100 perioperatively. The correlation analysis and paired Student t test between variables from Embletta and from standard PSG were used to evaluate the accuracy of Embletta. The quality of PSG recordings with Embletta was summarized. Twenty-one patients completed sleep study on both systems; ten females and ten males, age was 54 ± 11 and BMI was 36 ± 9. There was a significant correlation between the majority of parameters from standard PSG and Embeltta X100 with manual scoring. The inter-rater agreement was substantial to perfect at different AHI cutoffs with a Kappa coefficient of 0.69 to 1. A significant correlation between standard PSG and Embletta X100 with automatic scoring was found only in AHI and a few other parameters. In 385 patients, 1,002 perioperative PSG recordings were carried out with Embletta. Of them, 889(88.7%) were technically good and 90(9%) technically acceptable. Only 23 (2.3%) PSG recordings failed. Embletta X100, installed by a well-trained sleep technician, is a good alternative when standard PSG was not available or impractical. Manual scoring by a certified PSG technologist is the key for reliable results.

Current Clinical Services in Sleep-Related Breathing Disorders in Shiga Prefecture

We studied clinical services for sleep-related disorders in breathing (SDB) by questionnaires sent to 150 hospitals and clinics in Shiga Prefecture identified through sleep clinic and Shiga hospital referrals. Responses returned by 82 (54.7%) showed that SDB cases 6,448 numbered a year, with 936 new and follow-up 5,370. Of these, 94.3% visited medical institutions in the cities of Otsu or Kusatsu. Shiga Prefecture has 9 beds for polysomnography (PSG) at 10 facilities. PSG conducted annually numbered 753 with most done in hospitals. PSG and portable sleep monitoring were not done in 3 areas. We estimated the annual number of PSGs in Shiga Prefecture in 2008 to be 53.8/100,000. All sleep technicians are employed part-time, severely limiting number of split-night, multiple sleep latency, and maintenance wakefulness tests. In conclusion, SDB treatment in Shiga Prefecture is concentrated at 2 hospitals in Otsu and Kusatsu, and annual PSGs per 100,000 are insufficient. SDB treatment and networks must therefore be built up among home doctors and medical institutions if SDB practice is to improve.

Essentials of Polysomnography: A Training Guide and Reference for Sleep Technicians

Essentials of Polysomnography: A Training Guide and Reference for Sleep Technicians

Clinical analysis of upper airway resistance syndrome and obstructive sleep apnea-hypopnea syndrome in children

To analyze the similarities and differences of the clinical manifestations between the children with upper airway resistance syndrome (UARS) and obstructive sleep apnea-hypopnea syndrome (OSAHS), and to explore the clinical features and characteristics of sleep respiratory parameters. Using the double-blind method, all children were diagnosed as UARS or OSAHS through the polysomnography test and the results of all children were analyzed by a sleep technician and an otolaryngologist. Another ENT doctor recorded their clinical and physical examination in detail. Polysomnography showed that the apnea-hypopnea index (AHI) and the lowest oxygen in 253 children with OSAHS were 3.60[2.00;7.55] times/h and 0.90[0.85;0.91], and were 0.90[0.50;1.10] times/h and 0.95[0.92;0.96] in 102 children with UARS, the difference of the two groups by rank test was statistically significant. The proportion of UARS and OSAHS was more common during preschool period than during school-age period. The chief complaint in two groups was sleep snoring, and the main symptoms were sleep restless, attention deficit/hyperactivity and breath with mouth open. The incidence rate of above symptoms were as follows, 94.1%, 72.5%, 62.7% and 37.3% in children with UARS, 92.9%, 78.7%, 57.7% and 45.5% in children with OSAHS. The difference was not significant by chi-square test (P>0.05). Tonsil and adenoid hypertrophy were also observed in the two groups, the difference was not significant (chi2 = 0.27, P= 0.87). However, the children with OSAHS were more apt to have the sleep apnea than with UARS, the difference was statistically significant (chi2 = 34.07, P<0.001). The clinical manifestations of two groups are similar, the difference between UARS and OSAHS can not be determined by the patient's clinical performance. Sleep apnea can be more easily observed in children with OSAHS than that in UARS, the final diagnosis is based on polysomnography.

So you want to be … an anaesthetist

Did you spend 5 years at medical school to become a sleep technician…

An investigation of the validity of the Lifeshirt in comparison to standard polysomnography in the detection of obstructive sleep apnea

Background Due to the cost and waiting times for traditional sleep studies, there is great interest in finding alternatives for the diagnosis of sleep apnea. Several alternatives exist, including ambulatory devices. Our laboratory utilized one such device, a form-fitting vest called the Lifeshirt, and compared its accuracy to that of polysomnography (PSG). Methods PSG was performed with simultaneous utilization of the Lifeshirt on 50 individuals who met screening criteria for obstructive sleep apnea. Participants came to the sleep laboratory approximately 2 h before their normal bedtime. A sleep technician prepared each participant for PSG and Lifeshirt monitoring. “Lights Out” occurred when the participant was ready for bed, and time in bed was standardized to approximately 7 h. PSGs were scored by experienced personnel in our laboratory, while Lifeshirt data were sent electronically to the Lifeshirt manufacturer for analysis. The major variable that was compared between PSG and Lifeshirt was the apnea hypopnea index (AHI), or the number of apneas and hypopneas per hour. Due to incomplete data on two participants, analyses were completed on 48 individuals. Results Sensitivity of the Lifeshirt ranged from .85 (AHI of ⩾5) to 1.00 (AHI of ⩾25). Specificity ranged from .67 to 1.00. Using the Bland–Altman technique of determining agreement, the mean difference between the AHI of the Lifeshirt and PSG was 1.02 (±16.36). When these values are plotted, every case falls within the limits of agreement, with one exception. Conclusions The Lifeshirt compared favorably with PSG and could be used with considerable confidence for the screening of patients with suspected obstructive sleep apnea.

Quantity and Quality of Sleep in the Surgical Intensive Care Unit: Are Our Patients Sleeping?

The lack of adequate sleep during intensive care unit (ICU) admission is a frequently overlooked complication. Disrupted sleep is associated with immune system dysfunction, impaired resistance to infection, as well as alterations in nitrogen balance and wound healing. The effects of surgical ICU admission on patients' sleep quality and architecture remain poorly defined. The purpose of this study was to describe the quantity and quality of sleep as well as sleep architecture, as defined by polysomnography (PSG), in patients cared for in the surgical ICU. A prospective observational cohort study was performed at our urban Level I trauma center. A convenience sample of surgical or trauma ICU patients underwent continuous PSG for up to 24 hours to evaluate sleep patterns. A certified sleep technician performed, monitored, and scored all PSG recordings. A single neurologist trained in PSG interpretation reviewed all PSG recordings. chi goodness-of-fit analysis was performed to detect differences in the proportion of time spent in stages 1 and 2 (superficial stages), stages 3 and 4 (deep stages), or rapid eye movement (REM) sleep between study patients and healthy historical controls. All PSG recordings were performed greater than 24 hours after the administration of a general anesthetic. Patients with traumatic brain injury were excluded. Sixteen patients were selected to undergo PSG recordings. Median age was 37.5 years (range, 20-83), 81.3% were male patients, 62.5% were injured, and 31.3% were mechanically ventilated. Total PSG recording time was 315 hours (mean, 19.7 hours per patient), total sleep time captured by PSG was 132 hours (mean, 8.28 hours per patient), and there were 6.2 awakenings per hour of sleep measured. ICU patients had an increase in the proportion of time spent in the superficial stages of sleep, and a decrease in the proportion of time spent in the deeper stages of sleep as well as a decrease in REM sleep compared with healthy controls (p < 0.001). Patients do achieve measurable sleep while cared for in a surgical ICU setting. However, sleep is fragmented and the quality of sleep is markedly abnormal with significant reductions in stages 3 and 4 and REM, the deeper restorative stages of sleep. Further studies on the effects of a strategy to promote sleep during ICU care are warranted.

The Man Who Fought in Sleep

A 60-year-old Caucasian man presents to a sleep disorders clinic with a chief complaint of abnormal body movements and talking during sleep. He is accompanied by his wife, who reports that the patient frequently shouts, punches, and kicks during sleep. The episodes began 4 to 5 years ago. Initially, they were sporadic but have been occurring once or twice a week lately, usually in the later part of the night. Three nights ago, the patient punched his wife violently in sleep and then pushed her away while yelling loudly. When she woke him up, he said that he was dreaming that he was in a jungle, fighting a bear. She is now afraid to sleep with him and sleeps in a different bed. The patient feels embarrassed and says that he has frequently experienced dreams in which he fights an animal or a monster. He denies any daytime complaints. The patient has a history of hypertension and hypercholesterolemia. His medications include metoprolol 50 mg twice a day and simvastatin 20 mg once a day. He smoked 1 pack of cigarette a day for 35 years until he quit 8 years ago. He drinks 1 to 2 beers on the weekend but denies alcohol abuse. On examination, the patient is an overweight male. The remainder of the findings on physical examination are normal. The patient undergoes overnight polysomnography. The accompanying figure shows an epoch from the polysomnogram. The sleep technician notes that the patient was kicking and shouting in sleep during this episode. Figure 1 An epoch from the patient's polysomnogram. EOG refers to electrooculogram; EMG, electromyogram; EKG, electrocardiogram. Which of the following is true about this disorder? The dreams are usually associated with abrupt awakenings and a feeling of panic, with full alertness occurring immediately upon awakening. The patient has a higher likelihood of developing multiple system atrophy. The patient has a higher likelihood of having iron-deficiency anemia. Secondary enuresis and tongue-biting are common features. Answer: B Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by a loss of the normal skeletal muscle atonia during REM phase of sleep. The disorder frequently manifests as enactment of dreams, resulting in shouting, flailing of arms, and moving and kicking during sleep, and may result in injury to self and to others.1 It is common for people affected by this disorder to report a history of vivid, intense, and violent dreams. RBD is predominantly a disease of older men (older than 50 years of age), with the mean age at presentation in 1 series being approximately 64 years.2 The polysomnogram frequently reveals augmented phasic or tonic muscular activity during REM sleep. The accompanying epoch demonstrates increased activity in chin -electromyogram and leg-electromyogram leads during REM stage, along with technician's notation, “talking in sleep.” RBD may be idiopathic in approximately 60% of cases, other cases being associated with neurologic disorders such as ischemic cerebrovascular disease, subarachnoid hemorrhage, Parkinson disease, multiple system atrophy, progressive supranuclear palsy, Shy-Drager syndrome, olivopontocerebellar degeneration, and multiple sclerosis. Many patients with “idiopathic” RBD will develop neurodegenerative disorders many years after the onset of parasomnia (choice B).3 Clonazepam is an effective therapy for most persons with RBD.1 This disorder should be differentiated from nightmares, which can occur at any age and are usually followed by abrupt awakenings accompanied by a sensation of fear or panic (choice A). Iron-deficiency anemia (choice C) is associated with restless leg syndrome and not RBD. Secondary enuresis and tongue biting (choice D) are features of epilepsy as opposed to RBD. Although sleep-related epilepsy would be a consideration in persons with focal limb movements during sleep, the history in this case is typical of RBD.

Polysomnography in Hospitalized Patients Using a Wireless Wide Area Network

Sleep-disordered breathing and hypoxemia frequently underlie many common medical conditions for which patients require hospitalization. Sleep apnea is associated with adverse cardiovascular, neurovascular, inflammatory, and metabolic consequences, many of which can be reversed with nasal continuous positive airway pressure. Although polysomnography is the gold standard for outpatient evaluation of sleep apnea, it has not been used for establishing the diagnosis or as a means to intervene with evidence-based therapy in the hospital setting. A 468-bed tertiary-care facility for adults in which an 801.11b wireless network supplements a typical hardwired local area network. We developed a technique to perform 16-channel polysomnography on any patient in any location in the hospital without interfering with routine nursing care. Qualified sleep technicians are able to remotely adjust electrophysiologic and respiratory parameters, as well as control continuous positive airway pressure titration. The study can also be monitored from any location with Internet access using a HIPAA-compliant virtual private network. Polysomnography was performed on 51 inpatients (age 26 to 89 years; 31 men). Mean (SD) body mass index measured 34.1 kg/m(2) (12.4). Cardiac disease (47%) and neurologic disease (27%) were the most frequent primary indications for admission. Data acquisition was not disrupted due to connectivity problems. The most frequent deficiencies were reduced sleep time (range 0.8-6.5 hours; mean [SD] 3.3 hours [1.6]) and reduced or absent rapid eye movement sleep. Mean (SD) apnea-hypopnea index measured 35.9 events per hour of sleep (SD 26.3) and 19.4 events per hour of total recording time (SD 17.5). Polysomnography measurements transmitted across a wireless wide area network increases the capacity of the traditional hospital-based sleep laboratory. This technique can facilitate early implementation of appropriate therapy and may reverse underlying factors associated with the primary cause of hospitalization. Indications and standards of practice need to be specifically established for inpatient polysomnography.

Troubleshooting and elimination of artifact in polysomnography.

A sleep technician who runs a sleep study without understanding the basis of the signals being acquired can spend a lot of time and energy trying to improve poor signal quality without success. Poor signal quality often results in an image that cannot be interpreted or is difficult to interpret, and extensive troubleshooting often results in a very disrupted sleep study. This article addresses trouble-shooting and elimination of artifact in polysomnography.