Performance and symptom validity indicators among children undergoing cognitive surveillance following treatment for craniopharyngioma

Background

Performance validity tests (PVTs) and symptom validity tests (SVTs) are essential to neuropsychological evaluations, helping ensure findings reflect true abilities or concerns. It is unclear how PVTs and SVTs perform in children who received radiotherapy for brain tumors. Accordingly, we investigated the rate of noncredible performance on validity indicators as well as associations with fatigue and lower intellectual functioning.

Methods

Embedded PVTs and SVTs were investigated in 98 patients with pediatric craniopharyngioma undergoing proton radiotherapy (PRT). The contribution of fatigue, sleepiness, and lower intellectual functioning to embedded PVT performance was examined. Further, we investigated PVTs and SVTs in relation to cognitive performance at pre-PRT baseline and change over time.

Results

SVTs on parent measures were not an area of concern. PVTs identified 0-31% of the cohort as demonstrating possible noncredible performance at baseline, with stable findings 1 year following PRT. Reliable digit span (RDS) noted the highest PVT failure rate; RDS has been criticized for false positives in pediatric populations, especially children with neurological impairment. Objective sleepiness was strongly associated with PVT failure, stressing need to consider arousal level when interpreting cognitive performance in children with craniopharyngioma. Lower intellectual functioning also needs to be considered when interpreting task engagement indices as it was strongly associated with PVT failure.

Conclusions

Embedded PVTs should be used with caution in pediatric craniopharyngioma patients who have received PRT. Future research should investigate different cut-off scores and validity indicator combinations to best differentiate noncredible performance due to task engagement versus variable arousal and/or lower intellectual functioning.

Health-related quality of life, obesity, fragmented sleep, fatigue, and psychosocial problems among youth with craniopharyngioma

OBJECTIVE

Youth with craniopharyngioma experience weight gain, fragmented sleep, excessive daytime sleepiness (EDS), fatigue, and psychosocial problems that negatively impact their overall health-related quality of life (HRQoL). Greater hypothalamic tumor involvement (HI) may be associated with higher rates or severity of these impairments; however, the direct and indirect impact of HI on the physical and psychosocial consequences associated with pediatric craniopharyngioma remain unclear. The purpose of the current study was to examine relations between HI, body mass index (BMI), fragmented sleep, EDS, fatigue, psychosocial problems, and HRQoL among youth with craniopharyngioma.

METHODS

Eighty-four youth with craniopharyngioma (M_age  = 10.27 ± 4.3 years, 53.6% female, 64.3% White) were assessed with actigraphy, nocturnal polysomnography, and multiple sleep latency tests prior to proton therapy, when indicated. Caregivers completed measures of fatigue, psychosocial functioning, and HRQoL.

RESULTS

Hypothalamic tumor involvement was associated with greater BMI (Est. = 2.97, p = 0.003) and daytime sleepiness (Est. = 2.53, p = 0.01). Greater fatigue predicted more psychosocial problems (Est. = 0.29, p < 0.001) and lower HRQoL (Est. = 0.23, p = 0.001). Psychosocial problems also predicted lower HRQoL (Est. = -0.34, p = 0.004). Fragmented sleep (Est. = 0.03, p = 0.04) and fatigue (Est. = 0.10, p = 0.02) indirectly predicted lower HRQoL through psychosocial problems.

CONCLUSIONS

Youth with craniopharyngioma with greater HI may benefit from weight reduction interventions and management of excessive sleepiness. Patients should be prospectively monitored for sleep problems, fatigue, and psychosocial problems, as these patients may benefit from interventions targeting fatigue and psychosocial health to improve HRQoL.

Sleep and daytime behavior in individuals with Christianson Syndrome

BACKGROUND

The objectives of this study were to: 1) characterize the sleep behaviors and symptoms of individuals with Christianson Syndrome (CS) by means of validated questionnaires; and 2) determine their associations with daytime emotional and behavioral symptoms in this population.

METHODS

Participants included 16 boys genetically diagnosed with CS, between 2.5 and 40 years of age (M = 14.5 ± 8.08). Parents completed questionnaires regarding the sleep, daytime behavior, and health of their child.

RESULTS

Of the participants, 31% did not obtain the recommended amount of sleep for their age, 43% experienced a prolonged sleep latency, and 88% had a clinical or sub-clinical score for at least one subscale of the Sleep Disturbance Scale for Children (SDSC). Specific problems detected included insomnia, sleep-wake transition disorders, periodic limb movements in sleep, and sleep related breathing disorders. About half of the participants manifested emotional and behavioral problems at clinical levels. Higher levels of sleep disturbances were associated with higher levels of behavioral and emotional daytime symptoms.

CONCLUSIONS

Sleep problems are common in individuals with CS and are associated with daytime behavioral and emotional symptoms.

Actigraphy versus Polysomnography to Measure Sleep in Youth Treated for Craniopharyngioma

OBJECTIVE/BACKGROUND

Youth with craniopharyngioma are at increased risk for excessive daytime sleepiness and narcolepsy. Polysomnography (PSG) is the gold standard for diagnosing sleep disorders, but is time-intensive, costly, and does not offer an in vivo measure of typical sleep routine. We determined the sensitivity, specificity, and accuracy of actigraphy compared with PSG in measuring nocturnal sleep in pediatric craniopharyngioma.

PARTICIPANTS

Fifty youth with craniopharyngioma (age 3-20 years) were assessed by overnight PSG and concurrent actigraphy after surgical resection and before proton therapy.

METHODS

PSG and actigraphy data were synchronized utilizing an epoch-by-epoch comparison method. Sensitivity, specificity, and accuracy were calculated using measures of true wake, true sleep, false wake, and false sleep. Bland-Altman plots were conducted to further assess level of agreement.

RESULTS

Actigraphy was 93% sensitive (true sleep [TS]) and 87% accurate (ability to detect TS and true wake) in measuring sleep versus wakefulness and was a reliable measure of sleep efficiency (SE) and sleep latency (SL). Specificity (true wake) was poor (55%) and total sleep time (TST) was underestimated by an average of 15.1 min. Wake after sleep onset (WASO) was overestimated by an average of 14.7 min.

CONCLUSIONS

Actigraphy was highly sensitive and accurate and was a reliable measure of SE and SL. Although there were differences in TST and WASO measurements by actigraphy and PSG, our findings provide the basis for future studies on the use of actigraphy to monitor treatment response to wakefulness-promoting medications in youth with craniopharyngioma who demonstrate excessive daytime sleepiness.

Sensitivity and Specificity of the Modified Epworth Sleepiness Scale in Children With Craniopharyngioma

STUDY OBJECTIVES

Children with craniopharyngioma are at risk for excessive daytime sleepiness (EDS). Multiple Sleep Latency Testing (MSLT) is the gold standard for objective evaluation of EDS; however, it is time and resource intensive. We compared the reliability, sensitivity, and specificity of the modified Epworth Sleepiness Scale (M-ESS) and MSLT in monitoring EDS in children with craniopharyngioma.

METHODS

Seventy patients (ages 6 to 20 years) with craniopharyngioma completed the M-ESS and were evaluated by polysomnography and MSLT. Evaluations were made after surgery, if performed, and before proton therapy.

RESULTS

MSLT revealed that 66 participants (81.8%) had EDS, as defined by a mean sleep latency (MSL) < 10 minutes, with only 28.8% reporting EDS on the M-ESS by using a cutoff score of 10. The M-ESS demonstrated adequate internal consistency and specificity (91.7%) but poor sensitivity (33.3%) with the established cutoff score of 10. A cutoff score of 6 improved the sensitivity to 64.8% but decreased the specificity to 66.7%.

CONCLUSIONS

Patients with craniopharyngioma are at high risk for EDS, as documented objectively on the MSLT, but they frequently do not recognize or accurately report their sleepiness. Future sleep studies should investigate whether specific items or alternative self- and parent-reported measures of sleepiness may have greater clinical utility in monitoring sleepiness in this population.

Prevalence, risk factors, and response to treatment for hypersomnia of central origin in survivors of childhood brain tumors

Daytime sleepiness is recognized in childhood brain tumor survivors. Our objective was to determine prevalence, risk factors for PSG/MLST proven hypersomnia/narcolepsy, and response to stimulants in childhood brain tumor survivors. Standard PSG/MSLT criteria were used to diagnose hypersomnia/narcolepsy. Medical records of brain tumor survivors having undergone a PSG/MSLT were reviewed for the diagnostic code of hypersomnia/narcolepsy. Survivors with hypersomnia/narcolepsy were matched with 2-3 survivors without reported hypersomnia/narcolepsy by age at tumor diagnosis, gender, and time from tumor diagnosis. Between January 2000 to April 2015, 39 of the 2336 brain tumor patients treated at our institution were diagnosed with hypersomnia/narcolepsy for a prevalence rate of 1670/100,000. Hypersomnia/narcolepsy was diagnosed at a median of 6.1 years (range 0.4-13.2) from tumor diagnosis and 4.7 years (range - 1.5 to 10.4) from cranial radiation. Midline tumor location (OR 4.6, CI 1.7-12.2, p = 0.002) and anti-epilepsy drug (AED) use (OR 11, CI 2.4-54) correlated with hypersomnia/narcolepsy while radiation dose > 30 Gray trended towards significance (OR 1.8, CI 0.9-3.6); posterior fossa tumor location reduced the risk (OR 0.1, CI 0.04-0.5, p = 0.002). AED use also correlated with midline tumor location. Thirty-seven survivors were treated with stimulants and reported improved wakefulness and school performance [response rate CI 0.97 (0.86-0.99) and 0.83 (0.65-0.94)]. Prevalence of hypersomnia/narcolepsy among childhood brain tumor survivors was higher than the general population. Tumor location and radiation dose were possible risk factors, and stimulants were reported to be beneficial.

Training, knowledge, attitudes and practices of Canadian health care providers regarding sleep and sleep disorders in children

Background

Sleep disorders are prevalent in children and are associated with significant comorbidity.

Objective

To assess the training, knowledge, attitudes and practices of Canadian health care providers (HCPs) regarding sleep disorders in children.

Method

A 42-item survey, designed to collect information on frequency of paediatric sleep disorders-related screening and diagnosis, implementation of evidence-based interventions and related knowledge base, was completed by HCPs.

Results

Ninety-seven HCPs completed the survey. One per cent obtained training in paediatric sleep during undergraduate training and 3% obtained such training during their residencies, yet 34.9% estimated that 25 to 50% of their patients suffered from sleep disorders. Most HCPs thought that sleep disorders significantly impacted children's health and daytime function. Most HCPs screened for developmental sleep issues, but not consistently for sleep disorders. Most recommended evidence-based behavioural interventions for behavioural sleep disorders, but some also reported behavioural interventions that were not first-line or recommended. Inadequate knowledge regarding melatonin use was evident. Most participants reported rarely/never ordering a sleep study for a child with suspected obstructive sleep apnea (OSA). Most were familiar with surgical and weight loss management options for OSA; many were unfamiliar with benefits of continuous positive airway pressure. Participants' knowledge scores were highest on developmental and behavioural aspects of sleep, and lowest on sleep disorders.

Conclusions

HCPs exhibit significant gaps in their knowledge, screening, evaluation and treatment practices for paediatric sleep disorders. Training at the undergraduate, graduate and postgraduate levels, as well as Continuing Medical Education are needed to optimize recognition, treatment and follow-up of paediatric sleep disorders.

Delaying Middle School and High School Start Times Promotes Student Health and Performance: An American Academy of Sleep Medicine Position Statement

ABSTRACT

During adolescence, internal circadian rhythms and biological sleep drive change to result in later sleep and wake times. As a result of these changes, early middle school and high school start times curtail sleep, hamper a student's preparedness to learn, negatively impact physical and mental health, and impair driving safety. Furthermore, a growing body of evidence shows that delaying school start times positively impacts student achievement, health, and safety. Public awareness of the hazards of early school start times and the benefits of later start times are largely unappreciated. As a result, the American Academy of Sleep Medicine is calling on communities, school boards, and educational institutions to implement start times of 8:30 AM or later for middle schools and high schools to ensure that every student arrives at school healthy, awake, alert, and ready to learn.

Consensus Statement of the American Academy of Sleep Medicine on the Recommended Amount of Sleep for Healthy Children: Methodology and Discussion

ABSTRACT

Members of the American Academy of Sleep Medicine developed consensus recommendations for the amount of sleep needed to promote optimal health in children and adolescents using a modified RAND Appropriateness Method. After review of 864 published articles, the following sleep durations are recommended: Infants 4 months to 12 months should sleep 12 to 16 hours per 24 hours (including naps) on a regular basis to promote optimal health. Children 1 to 2 years of age should sleep 11 to 14 hours per 24 hours (including naps) on a regular basis to promote optimal health. Children 3 to 5 years of age should sleep 10 to 13 hours per 24 hours (including naps) on a regular basis to promote optimal health. Children 6 to 12 years of age should sleep 9 to 12 hours per 24 hours on a regular basis to promote optimal health. Teenagers 13 to 18 years of age should sleep 8 to 10 hours per 24 hours on a regular basis to promote optimal health. Sleeping the number of recommended hours on a regular basis is associated with better health outcomes including: improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health. Regularly sleeping fewer than the number of recommended hours is associated with attention, behavior, and learning problems. Insufficient sleep also increases the risk of accidents, injuries, hypertension, obesity, diabetes, and depression. Insufficient sleep in teenagers is associated with increased risk of self-harm, suicidal thoughts, and suicide attempts.

COMMENTARY

A commentary on this article apears in this issue on page 1439.

Investigating the Role of Hypothalamic Tumor Involvement in Sleep and Cognitive Outcomes Among Children Treated for Craniopharyngioma

OBJECTIVE

Despite excellent survival prognosis, children treated for craniopharyngioma experience significant morbidity. We examined the role of hypothalamic involvement (HI) in excessive daytime sleepiness (EDS) and attention regulation in children enrolled on a Phase II trial of limited surgery and proton therapy.

METHODS

Participants completed a sleep evaluation (N = 62) and a continuous performance test (CPT) during functional magnetic resonance imaging (fMRI; n = 29) prior to proton therapy.

RESULTS

EDS was identified in 76% of the patients and was significantly related to increased HI extent (p = .04). There was no relationship between CPT performance during fMRI and HI or EDS. Visual examination of group composite fMRI images revealed greater spatial extent of activation in frontal cortical regions in patients with EDS, consistent with a compensatory activation hypothesis.

CONCLUSION

Routine screening for sleep problems during therapy is indicated for children with craniopharyngioma, to optimize the timing of interventions and reduce long-term morbidity.

Recommended Amount of Sleep for Pediatric Populations: A Consensus Statement of the American Academy of Sleep Medicine

ABSTRACT

Sleep is essential for optimal health in children and adolescents. Members of the American Academy of Sleep Medicine developed consensus recommendations for the amount of sleep needed to promote optimal health in children and adolescents using a modified RAND Appropriateness Method. The recommendations are summarized here. A manuscript detailing the conference proceedings and the evidence supporting these recommendations will be published in the Journal of Clinical Sleep Medicine.

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

OBJECTIVE

This comprehensive, evidence-based review provides a systematic analysis of the literature regarding the validity, reliability, and clinical utility of polysomnography for characterizing breathing during sleep in children. Findings serve as the foundation of practice parameters regarding respiratory indications for polysomnography in children.

METHODS

A task force of content experts performed a systematic review of the relevant literature and graded the evidence using a standardized grading system. Two hundred forty-three evidentiary papers were reviewed, summarized, and graded. The analysis addressed the operating characteristics of polysomnography as a diagnostic procedure in children and identified strengths and limitations of polysomnography for evaluation of respiratory function during sleep.

RESULTS

The analysis documents strong face validity and content validity, moderately strong convergent validity when comparing respiratory findings with a variety of relevant independent measures, moderate-to-strong test-retest validity, and limited data supporting discriminant validity for characterizing breathing during sleep in children. The analysis documents moderate-to-strong test-retest reliability and interscorer reliability based on limited data. The data indicate particularly strong clinical utility in children with suspected sleep related breathing disorders and obesity, evolving metabolic syndrome, neurological, neurodevelopmental, or genetic disorders, and children with craniofacial syndromes. Specific consideration was given to clinical utility of polysomnography prior to adenotonsillectomy (AT) for confirmation of obstructive sleep apnea syndrome. The most relevant findings include: (1) recognition that clinical history and examination are often poor predictors of respiratory polygraphic findings, (2) preoperative polysomnography is helpful in predicting risk for perioperative complications, and (3) preoperative polysomnography is often helpful in predicting persistence of obstructive sleep apnea syndrome in patients after AT. No prospective studies were identified that address whether clinical outcome following AT for treatment of obstructive sleep apnea is improved in association with routine performance of polysomnography before surgery in otherwise healthy children. A small group of papers confirm the clinical utility of polysomnography for initiation and titration of positive airway pressure support.

CONCLUSIONS

Pediatric polysomnography shows validity, reliability, and clinical utility that is commensurate with most other routinely employed diagnostic clinical tools or procedures. Findings indicate that the "gold standard" for diagnosis of sleep related breathing disorders in children is not polysomnography alone, but rather the skillful integration of clinical and polygraphic findings by a knowledgeable sleep specialist. Future developments will provide more sophisticated methods for data collection and analysis, but integration of polysomnographic findings with the clinical evaluation will represent the fundamental diagnostic challenge for the sleep specialist.

Treatment of narcolepsy and other hypersomnias of central origin

OBJECTIVE

The purpose of this paper is to summarize current knowledge about treatment of narcolepsy and other hypersomnias of central origin.

METHODS

The task force performed a systematic and comprehensive review of the relevant literature and graded the evidence using the Oxford grading system. This paper discusses the strengths and limitations of the available evidence regarding treatment of these conditions, and summarizes key information about safety of these medications. Our findings provide the foundation for development of evidence-based practice parameters on this topic by the Standards of Practice Committee of the American Academy of Sleep Medicine.

RESULTS

The majority of recent papers in this field provide information about use of modafinil or sodium oxybate for treatment of sleepiness associated with narcolepsy. Several large randomized, placebo-controlled studies indicate that modafinil and sodium oxybate are effective for treatment of hypersomnia due to narcolepsy. We identified no studies that report direct comparison of these newer medications versus traditional stimulants, or that indicate what proportion of patients treated initially with these medications require transition to traditional stimulants or to combination therapy to achieve adequate alertness. As with the traditional stimulants, modafinil and sodium oxybate provide, at best, only moderate improvement in alertness rather than full restoration of alertness in patients with narcolepsy. Several large randomized placebo-controlled studies demonstrate that sodium oxybate is effective for treatment of cataplexy associated with narcolepsy, and earlier studies provide limited data to support the effectiveness of fluoxetine and tricyclic antidepressants for treatment of cataplexy. Our findings indicate that very few reports provide information regarding treatment of special populations such as children, older adults, and pregnant or breastfeeding women. The available literature provides a modest amount of information about improvement in quality of life in association with treatment, patient preferences among the different medications, or patient compliance.

CONCLUSION

Several recent studies provide evidence that modafinil and sodium oxybate are effective for treatment of hypersomnia due to narcolepsy. No studies were identified that report direct comparison of these newer medications with traditional stimulants. Despite significant advances in understanding the pathophysiology of narcolepsy, we do not have an ideal treatment to restore full and sustained alertness. Future investigations should be directed toward development of more effective and better tolerated therapies, and primary prevention.

The scoring of respiratory events in sleep: reliability and validity

The American Academy of Sleep Medicine Task Force on Respiratory Scoring reviewed the evidence that addresses: the validity of specific sensors in detecting airflow, tidal volume, oxyhemoglobin saturation, and CO2; the reliability of specific scoring approaches for quantifying sleep related breathing disorders (SRBD); and the validity of using various definitions of the apnea hypopnea index (AHI) as assessed by the strength and consistency of associations with several comorbidities (hypertension, cardiovascular disease, sleepiness, impaired quality of life, and accidents). The evidence was based on a literature search of relevant articles published through December 2004, which resulted in identifying and extracting data from 182 articles, which were graded using standardized approaches. Diverse physiological sensors have been utilized to quantify airflow limitation in patients with suspected SRBD. Although thermistry appears appropriate for identifying apneas, the available evidence did not indicate it provides valid quantification of airflow reduction. The emerging evidence evaluating the accuracy of signal detection against the gold standard measurements (e.g., pneumotachography) suggested the superiority of inductance plethysmography and nasal pressure transducers for detection of hypopneas, with some evidence that recordings from a nasal pressure transducer may better approximate flow/volume than uncalibrated inductance plethysmography. However, since the nasal pressure transducer has only recently been incorporated into large-scale studies, there are as of yet few data that address the predictive value of transducer-identified events relative to clinical or physiological outcomes. Very few studies directly compared the validity of alternative approaches for defining the duration, amplitude change, and use of corroborative data from desaturation or arousal for defining hypopneas. Many observational studies utilizing various designs and approaches for event detection have shown significant associations between measures of SRBD and health outcomes. Data from the 2 largest sleep cohort studies, the Sleep Heart Health Study and the Wisconsin Sleep Cohort, both used definitions of hypopneas based on "discernible" reductions of inductance plethysmography signals with associated desaturation and showed that the derived AHIs using these hypopnea definitions correlated with various indices of morbidity. However, it is not clear whether alternative definitions would provide comparable if not better prediction, or whether optimal approaches for event identification would vary for different outcomes. Despite these limitations, forming a consensus on optimal approaches for recording and measuring respiratory events is an important step toward generating data from different clinical or research laboratories that can be compared. However, additional research is needed, including direct comparisons of alternative measuring approaches for predicting clinical outcomes, with a need to address these issues in large samples across the age spectrum and with inclusion of promising new technology.

Discrete optical flow estimation methods and their application in the extraction of motion strength signals from video recordings of neonatal seizures

This work presents a methodology for the development of regularized optical flow computation methods for video. The proposed methodology is based on a discrete formulation of the optical flow problem. The optical flow computation methods produced by the proposed methodology are utilized to extract temporal motion strength signals from video recordings of neonatal seizures.

Quantifying motion in video recordings of neonatal seizures by feature trackers based on predictive block matching

This work introduces predictive block matching, a method developed to track motion in video by exploiting the advantages of block motion estimation and adaptive block matching. The proposed method relies on a pure translation motion model to estimate the displacement of a block between two successive video frames before initiating the search for the best match of the block tracked throughout the frame sequence. The search for the best match relies on adaptive block matching, which employs an update strategy based on Kalman filtering to account for the changing appearance of the block. Predictive block matching was used to extract motor activity signals from video recordings of neonatal seizures.

Automated Detection of Videotaped Neonatal Seizures Based on Motion Tracking Methods

This study was carried out during the second phase of the project "Video Technologies for Neonatal Seizures" and aimed at the development of a seizure detection system by training neural networks, using quantitative motion information extracted by motion tracking methods from short video segments of infants monitored for seizures. The motion of the infants' body parts was quantified by temporal motion trajectory signals extracted from video recordings by robust motion trackers, based on block motion models. These motion trackers were developed to autonomously adjust to illumination and contrast changes that may occur during the video frame sequence. The computational tools and procedures developed for automated seizure detection were evaluated on short video segments selected and labeled by physicians from a set of 240 video recordings of 54 patients exhibiting myoclonic seizures (80 segments), focal clonic seizures (80 segments), and random infant movements (80 segments). This evaluation provided the basis for selecting the most effective strategy for training neural networks to detect neonatal seizures as well as the decision scheme used for interpreting the responses of the trained neural networks. The best neural networks exhibited sensitivity and specificity above 90%. The best among the motion trackers developed in this study produced quantitative features that constitute a reliable basis for detecting myoclonic and focal clonic neonatal seizures. The performance targets of the second phase of the project may be achieved by combining the quantitative features described in this paper with those obtained by analyzing motion strength signals produced by motion segmentation methods.

Practice parameters for the use of continuous and bilevel positive airway pressure devices to treat adult patients with sleep-related breathing disorders

Positive airway pressure (PAP) devices are used to treat patients with sleep related breathing disorders (SRBD) including obstructive sleep apnea (OSA). Currently, PAP devices come in three forms: (1) continuous positive airway pressure (CPAP), (2) bilevel positive airway pressure (BPAP), and (3) automatic self-adjusting positive airway pressure (APAP). After a patient is diagnosed with OSA, the current standard of practice involves performing full, attended polysomnography during which positive pressure is adjusted to determine optimal pressure for maintaining airway patency. This titration is used to find a fixed single pressure for subsequent nightly usage. A task force of the Standards of Practice Committee of the American Academy of Sleep Medicine reviewed the available literature. Based on this review, the Standards of Practice Committee developed these practice parameters as a guideline for using CPAP and BPAP appropriately (an earlier review and practice parameters for APAP was published in 2002). Major conclusions and current recommendations are as follows: 1) A diagnosis of OSA must be established by an acceptable method. 2) CPAP is effective for treating OSA. 3) Full-night, attended studies performed in the laboratory are the preferred approach for titration to determine optimal pressure; however, split-night, diagnostic-titration studies are usually adequate. 4) CPAP usage should be monitored objectively to help assure utilization. 5) Initial CPAP follow-up is recommended during the first few weeks to establish utilization pattern and provide remediation if needed. 6) Longer-term follow-up is recommended yearly or as needed to address mask, machine, or usage problems. 7) Heated humidification and a systematic educational program are recommended to improve CPAP utilization. 8) Some functional outcomes such as subjective sleepiness improve with positive pressure treatment in patients with OSA. 9) CPAP and BPAP therapy are safe; side effects and adverse events are mainly minor and reversible. 10) BPAP may be useful in treating some forms of restrictive lung disease or hypoventilation syndromes associated with hypercapnia.

Automated detection of videotaped neonatal seizures based on motion segmentation methods

OBJECTIVE

This study was aimed at the development of a seizure detection system by training neural networks using quantitative motion information extracted by motion segmentation methods from short video recordings of infants monitored for seizures.

METHODS

The motion of the infants' body parts was quantified by temporal motion strength signals extracted from video recordings by motion segmentation methods based on optical flow computation. The area of each frame occupied by the infants' moving body parts was segmented by direct thresholding, by clustering of the pixel velocities, and by clustering the motion parameters obtained by fitting an affine model to the pixel velocities. The computational tools and procedures developed for automated seizure detection were tested and evaluated on 240 short video segments selected and labeled by physicians from a set of video recordings of 54 patients exhibiting myoclonic seizures (80 segments), focal clonic seizures (80 segments), and random infant movements (80 segments).

RESULTS

The experimental study described in this paper provided the basis for selecting the most effective strategy for training neural networks to detect neonatal seizures as well as the decision scheme used for interpreting the responses of the trained neural networks. Depending on the decision scheme used for interpreting the responses of the trained neural networks, the best neural networks exhibited sensitivity above 90% or specificity above 90%.

CONCLUSIONS

The best among the motion segmentation methods developed in this study produced quantitative features that constitute a reliable basis for detecting myoclonic and focal clonic neonatal seizures. The performance targets of this phase of the project may be achieved by combining the quantitative features described in this paper with those obtained by analyzing motion trajectory signals produced by motion tracking methods.

SIGNIFICANCE

A video system based upon automated analysis potentially offers a number of advantages. Infants who are at risk for seizures could be monitored continuously using relatively inexpensive and non-invasive video techniques that supplement direct observation by nursery personnel. This would represent a major advance in seizure surveillance and offers the possibility for earlier identification of potential neurological problems and subsequent intervention.

Automated Detection of Videotaped Neonatal Seizures of Epileptic Origin

PURPOSE

This study aimed at the development of a seizure-detection system by training neural networks with quantitative motion information extracted from short video segments of neonatal seizures of the myoclonic and focal clonic types and random infant movements.

METHODS

The motion of the infants' body parts was quantified by temporal motion-strength signals extracted from video segments by motion-segmentation methods based on optical flow computation. The area of each frame occupied by the infants' moving body parts was segmented by clustering the motion parameters obtained by fitting an affine model to the pixel velocities. The motion of the infants' body parts also was quantified by temporal motion-trajectory signals extracted from video recordings by robust motion trackers based on block-motion models. These motion trackers were developed to adjust autonomously to illumination and contrast changes that may occur during the video-frame sequence. Video segments were represented by quantitative features obtained by analyzing motion-strength and motion-trajectory signals in both the time and frequency domains. Seizure recognition was performed by conventional feed-forward neural networks, quantum neural networks, and cosine radial basis function neural networks, which were trained to detect neonatal seizures of the myoclonic and focal clonic types and to distinguish them from random infant movements.

RESULTS

The computational tools and procedures developed for automated seizure detection were evaluated on a set of 240 video segments of 54 patients exhibiting myoclonic seizures (80 segments), focal clonic seizures (80 segments), and random infant movements (80 segments). Regardless of the decision scheme used for interpreting the responses of the trained neural networks, all the neural network models exhibited sensitivity and specificity>90%. For one of the decision schemes proposed for interpreting the responses of the trained neural networks, the majority of the trained neural-network models exhibited sensitivity>90% and specificity>95%. In particular, cosine radial basis function neural networks achieved the performance targets of this phase of the project (i.e., sensitivity>95% and specificity>95%).

CONCLUSIONS

The best among the motion segmentation and tracking methods developed in this study produced quantitative features that constitute a reliable basis for detecting neonatal seizures. The performance targets of this phase of the project were achieved by combining the quantitative features obtained by analyzing motion-strength signals with those produced by analyzing motion-trajectory signals. The computational procedures and tools developed in this study to perform off-line analysis of short video segments will be used in the next phase of this project, which involves the integration of these procedures and tools into a system that can process and analyze long video recordings of infants monitored for seizures in real time.

Objective measures of sleepiness and wakefulness: application to the real world?

The impact of excessive sleepiness on the individual and on society is immense, and chronic sleepiness is one of the most common complaints evaluated by sleep medicine specialists. The author explores how measures of sleepiness and wakefulness using the Multiple Sleep Latency Test (MSLT) and the Maintenance of Wakefulness Test (MWT) can be clinically useful. A companion article presents a counterpoint discussion of the limitations and drawbacks associated with the MSLT and MWT. Both presentations use an evidence-based approach to understanding the operating characteristics of these tests, and the overall goal is to clarify for sleep medicine specialists the positive and negative attributes of the MSLT and MWT. The MSLT and MWT are the most widely accepted objective measures of an individual's ability to fall asleep and ability to remain awake, respectively. The MSLT is a well-validated and extensively published objective measure of the speed at which a subject falls asleep under standardized laboratory conditions, and it is associated with good to excellent interrater and intrarater reliability, and excellent test-retest reliability. The MSLT is indicated as part of the evaluation of suspected narcolepsy and it may be helpful in differentiating narcolepsy from idiopathic hypersomnia. Mean sleep latency values less than 5 minutes are observed in the majority of subjects with narcolepsy, and the presence of two or more sleep-onset rapid eye movement periods is strongly correlated with a diagnosis of narcolepsy. An MSLT should be performed to address specific clinical questions, and should not be used as a screening tool. The MWT has clinical usefulness in evaluating response to treatment following intervention for conditions associated with excessive sleepiness, and in assessing individuals who must remain awake for safety reasons. However, the sleep medicine specialist should not rely solely on mean sleep latency values as a single indicator of impairment or risk of accidents, but findings should be integrated with the clinical history, compliance, patient judgment, and other factors to form a global impression regarding the individual's response to treatment. Future challenges include refinement of normative ranges in different populations using rigorous statistical methods, and improved understanding of the specific operating characteristics of the MSLT and MWT in different age groups. Additional study is necessary regarding the impact of MSLT and MWT findings on clinical decision-making, patient outcome, and patient and physician satisfaction. From a safety and regulatory standpoint, additional study is needed to establish the correlation between MWT findings and the risk of adverse consequences of sleepiness such as accidents. Because the MSLT and MWT are in-laboratory tests, it is important that investigators also develop novel techniques that provide reliable assessment of sleepiness and wakefulness in the actual work environment over extended periods. In summary, the MSLT and MWT are not perfect tests, but they are the best objective measures currently available for characterization of ability to fall asleep and ability to remain awake.

Quantifying motion in video recordings of neonatal seizures by regularized optical flow methods

This paper presents the development of regularized optical flow computation methods and an evaluation of their performance in the extraction of quantitative motion information from video recordings of neonatal seizures. A general formulation of optical flow computation is presented and a mathematical framework for the development of practical tools for computing optical flow is outlined. In addition, this paper proposes an alternative formulation of the optical flow problem that relies on a discrete approximation of a family of quadratic functionals. These regularized optical flow computation methods are used to extract motion strength signals from video recordings of neonatal seizures.

Quantifying Motion in Video Recordings of Neonatal Seizures by Robust Motion Trackers Based on Block Motion Models

This paper introduces a methodology for the development of robust motion trackers for video based on block motion models. According to this methodology, the motion of a site between two successive frames is estimated by minimizing an error function defined in terms of the intensities at these frames. The proposed methodology is used to develop robust motion trackers that rely on fractional block motion models. The motion trackers developed in this paper are utilized to extract motor activity signals from video recordings of neonatal seizures. The experimental results reveal that the proposed motion trackers are more accurate and reliable than existing motion tracking methods relying on pure translation and affine block motion models.

Computerized Motion Analysis of Videotaped Neonatal Seizures of Epileptic Origin

PURPOSE

The main objective of this research is the development of automated video processing and analysis procedures aimed at the recognition and characterization of the types of neonatal seizures. The long-term goal of this research is the integration of these computational procedures into the development of a stand-alone automated system that could be used as a supplement in the neonatal intensive care unit (NICU) to provide 24-h per day noninvasive monitoring of infants at risk for seizures.

METHODS

We developed and evaluated a variety of computational tools and procedures that may be used to carry out the three essential tasks involved in the development of a seizure recognition and characterization system: the extraction of quantitative motion information from video recordings of neonatal seizures in the form of motion-strength and motor-activity signals, the selection of quantitative features that convey some unique behavioral characteristics of neonatal seizures, and the training of artificial neural networks to distinguish neonatal seizures from random infant behaviors and to differentiate between myoclonic and focal clonic seizures.

RESULTS

The methods were tested on a set of 240 video recordings of 43 patients exhibiting myoclonic seizures (80 cases), focal clonic seizures (80 cases), and random infant movements (80 cases). The outcome of the experiments verified that optical- flow methods are promising computational tools for quantifying neonatal seizures from video recordings in the form of motion-strength signals. The experimental results also verified that the robust motion trackers developed in this study outperformed considerably the motion trackers based on predictive block matching in terms of both reliability and accuracy. The quantitative features selected from motion-strength and motor-activity signals constitute a satisfactory representation of neonatal seizures and random infant movements and seem to be complementary. Such features lead to trained neural networks that exhibit performance levels exceeding the initial goals of this study, the sensitivity goal being >or=80% and the specificity goal being >or=90%.

CONCLUSIONS

The outcome of this experimental study provides strong evidence that it is feasible to develop an automated system for the recognition and characterization of the types of neonatal seizures based on video recordings. This will be accomplished by enhancing the accuracy and improving the reliability of the computational tools and methods developed during the course of the study outlined here.

Automated Extraction of Temporal Motor Activity Signals From Video Recordings of Neonatal Seizures Based on Adaptive Block Matching

This paper presents an automated procedure developed to extract quantitative information from video recordings of neonatal seizures in the form of motor activity signals. This procedure relies on optical flow computation to select anatomical sites located on the infants' body parts. Motor activity signals are extracted by tracking selected anatomical sites during the seizure using adaptive block matching. A block of pixels is tracked throughout a sequence of frames by searching for the most similar block of pixels in subsequent frames; this search is facilitated by employing various update strategies to account for the changing appearance of the block. The proposed procedure is used to extract temporal motor activity signals from video recordings of neonatal seizures and other events not associated with seizures.

Improving the Accuracy and Reliability of Motion Tracking Methods Used for Extracting Temporal Motor Activity Signals From Video Recordings of Neonatal Seizures

This paper presents an approach for improving the accuracy and reliability of motion tracking methods developed for video based on block motion models. This approach estimates the displacement of a block of pixels between two successive frames by minimizing an error function defined in terms of the pixel intensities at these frames. The minimization problem is made analytically tractable by approximating the error function using a second-order Taylor expansion. The improved reliability of the proposed method is illustrated by its application in the extraction of temporal motor activity signals from video recordings of neonatal seizures.

Case report: radical radiotherapy for early laryngeal cancer in a patient with human immunodeficiency virus: no evidence of increased toxicity

There are very few reported cases of laryngeal squamous cell carcinoma (SCC) in patients with a background of human immunodeficiency virus (HIV) infection. We report a case of a 42-year-old man who developed a T2 N0 left vocal cord well differentiated SCC with an 11 year history of HIV infection. He successfully completed a course of radical radiotherapy 66 Gy in 33 fractions over 47 days. During his treatment he experienced only a grade 1 Radiation Therapy Oncology Group (RTOG) acute toxicity reaction to the larynx and no weight loss. At 32 months follow up he remains disease free and has no significant late morbidity. Prior to his radiotherapy his CD4 count was 350 cells mm(-3); we discuss the view that the treatment chosen needs to be individually tailored with respect to the patient's immune status.

Narcolepsy in children

Core symptoms of narcolepsy are similar in children compared with adults, but expression may be different due to more severe manifestations, maturational factors, and the significant impact of symptoms on behavior and academic performance. Diagnosis of narcolepsy in children is often challenging and requires a detailed history followed by polysomnography and the Multiple Sleep Latency Test. Management involves a comprehensive approach, including patient and family education and emotional support; behavioral strategies, such as good sleep hygiene and planned naps; and pharmacologic intervention. Despite dramatic progress recently in understanding the etiology of human narcolepsy through molecular genetic investigations, the disorder remains a chronic and often disabling disease with major impact on the lives of children and their families.

Extraction of motion strength and motor activity signals from video recordings of neonatal seizures

This paper presents two methods developed to extract quantitative information from video recordings of neonatal seizures in the form of temporal motion strength and motor activity signals. Motion strength signals are extracted by measuring the area of the body parts that move during the seizure and the relative speed of motion using a combination of spatiotemporal subband decomposition of video, nonlinear filtering, and segmentation. Motor activity signals are extracted by tracking selected anatomical sites during the seizure using a modified version of a feature-tracking procedure developed for video, known as the Kanade-Lucas-Tomasi (KLT) algorithm. The experiments indicate that the temporal signals produced by the proposed methods provide the basis for differentiating myoclonic from focal clonic seizures and distinguishing these types of neonatal seizures from normal infant behaviors.

Practice parameters for the use of laser-assisted uvulopalatoplasty: an update for 2000

Laser-assisted uvulopalatoplasty (LAUP) is an outpatient surgical procedure which is in use as a treatment for snoring. LAUP also has been used as a treatment for sleep-related breathing disorders, including obstructive sleep apnea. The Standards of Practice Committee of the American Academy of Sleep Medicine reviewed the available literature, and developed these practice parameters as a guide to the appropriate use of this surgery. Adequate controlled studies on the LAUP procedure for sleep-related breathing disorders were not found in peer-reviewed journals. This is consistent with findings in the original practice parameters on LAUP published in 1994. The following recommendations are based on the review of the literature: LAUP is not recommended for treatment of sleep-related breathing disorders. However, it does appear to be comparable to uvulopalatopharyngoplasty (UPPP) for treatment of snoring. Individuals who are candidates for LAUP as a treatment for snoring should undergo a polysomnographic or cardiorespiratory evaluation for sleep-related breathing disorders prior to LAUP and periodic postoperative evaluations for the development of same. Patients should be informed of the best available information of the risks, benefits, and complications of the procedure.

Practice parameters for the treatment of narcolepsy: an update for 2000

Successful treatment of narcolepsy requires an accurate diagnosis to exclude patients with other sleep disorders, which have different treatments, and to avoid unnecessary complications of drug treatment. Treatment objectives should be tailored to individual circumstances. Modafinil, amphetamine, methamphetamine, dextroamphetamine, methylphenidate, selegiline, pemoline, tricyclic antidepressants, and fluoxetine are effective treatments for narcolepsy, but the quality of published clinical evidence supporting them varies. Scheduled naps can be beneficial to combat sleepiness, but naps seldom suffice as primary therapy. Regular follow up of patients with narcolepsy is necessary to educate patients and their families, monitor for complications of therapy and emergent of other sleep disorders, and help the patient adapt to the disease.

Childhood narcolepsy

Narcolepsy may present during childhood and is probably underrecognized and underdiagnosed in this population. The core symptoms of narcolepsy in children are similar to those in adults, but the expression may be different because of maturational factors. This report focuses on the presenting features that are unique to childhood narcolepsy and the appropriate diagnostic evaluation for suspected narcolepsy in children. Psychosocial and academic problems are almost universal in children with narcolepsy, and management strategies should address these areas. Although currently available stimulant medications may be helpful to some extent, the cornerstone of management is education, emotional and academic support, and careful follow-up over time. The overall goal for managing childhood narcolepsy is to assist the child and family in achieving optimal quality of life.

Rasmussen syndrome and long-term response to gamma globulin

Rasmussen syndrome (RS) is a severe and progressive focal epilepsy of unknown etiology that leads to deterioration of motor and cognitive function. We report a 14-year-old girl who developed epilepsia partialis continua involving the left hand, mild hemiparesis, and secondarily generalized seizures. RS was confirmed by brain biopsy. The patient has been treated with intravenous gamma globulin every 4 months for 46 months. The clinical course throughout this time has been distinctly atypical for RS, with no progression in motor or cognitive deficits and rare secondarily generalized seizures. Although the mechanism for action for gamma globulin in RS is not known, an immunomodulatory role has been postulated. Evidence of an immunologically mediated process in RS and clinical experience with a growing number of patients who benefit from immunomodulatory therapy suggest that a systematic study of the efficacy of gamma globulin in comparison with other forms of medical therapy is warranted.

The nurse practitioner's role in a pediatric sleep clinic

The assessment and management of pediatric sleep disorders frequently involves a multidisciplinary approach that includes many practice opportunities for the pediatric nurse practitioner. This article discusses the approach used in The Children's Sleep Clinic at The Children's Hospital of Alabama, where nurse practitioner involvement begins with telephone triage and progresses to collaborative management. Recommendations for future research include investigation of pediatric sleep disorders and research involving the outcome of nurse practitioner case management.