Increased Cortisol after Stress is Associated with Variability in Response Time in ADHD Children

Purpose

Children with attention-deficit/hyperactivity disorder (ADHD) often perform poorly during cognitive tests. We sought to evaluate cortisol as potential moderator of performance in mentally challenging tasks in children with ADHD.

Materials and Methods

Ninety clinic-referred children with ADHD were studied. Cortisol contents in saliva were measured before and after administration of a continuous performance test (CPT).

Results

Pre and post CPT cortisol levels were similar in 68 children. Children whose cortisol level increased after testing ( n = 22 ) displayed a significantly longer response time and increased response time variability scores as compared to children who did not display increase of cortisol after the CPT test. Even after controlling for the effects of response time and anxiety, the changes in cortisol levels were associated with effect on response time variability.

Conclusion

The patients who showed an increased cortisol level after stress displayed a higher variability in response time than the patients who showed no change or a decreased cortisol level. The result of the current study suggests that stress-induced high norepinephrine (NE) release may accompany poorer attention performance in patients with ADHD.     

Sleep Problems and Disorders among Adolescents with Persistent and Subthreshold Attention-deficit/Hyperactivity Disorders

Study Objectives:

To investigate the sleep schedules, problems, and disorders among adolescents with persistent attention-deficit/hyperactivity disorder (ADHD) and those with partially remitted ADHD symptoms.

Design:

A case-control study.

Setting:

National Taiwan University and schools in Taipei

Patients or Participants:

The sample included 281 adolescents (male, 85.4%; 145 with persistent ADHD, 136 with subthreshold ADHD), aged 11 to 17, who were diagnosed with ADHD, according to DSM-IV criteria, at the mean age of 6.7 years (SD = 3.0) and 185 unaffected control subjects.

Interventions:

N/A.

Measurements and Results:

We conducted psychiatric interviews of participants and their mothers using the Chinese Kiddie-Schedule for Affective Disorders and Schizophrenia-Epidemiology version for making the diagnoses of ADHD, other psychiatric disorders, and sleep problems or disorders. We also collected the medication treatment data and parent and teacher reports of ADHD-related symptoms. Our results showed that adolescents with a childhood diagnosis of ADHD according to DSM-IV criteria, regardless of persistent ADHD, were more likely to have current and lifetime sleep problems and sleep disorders according to DSM-IV (insomnia, sleep terrors, nightmares, bruxism, and snoring). The presence of at least 1 psychiatric comorbid condition increased the risks for insomnia and nightmares. The use of methylphenidate was not associated with further increased risk of sleep problems, except bruxism.

Conclusions:

Our findings support a relationship between ADHD and sleep problems, which can be partially explained by the psychiatric comorbidities, but did not support a disturbed sleep schedule. Our study suggests that mental health professionals should screen for sleep problems and psychiatric comorbidities among adolescents with a childhood diagnosis of ADHD regardless of the severity of current ADHD symptoms.

Citation:

Gau SSF; Chiang HL. Sleep problems and disorders among adolescents with persistent and subthreshold attention-deficit/hyperactivity disorders. SLEEP 2009;32(5):671-679.     

Sleep Disturbances in Prepubertal Children with Attention Deficit Hyperactivity Disorder: A Home Polysomnography Study

Study Objectives:

To examine sleep architecture and reported sleep problems in children with ADHD and normal controls, while considering the roles of pertinent moderating factors.

Design:

Overnight sleep recordings were conducted in 15 children diagnosed with ADHD (DSM-IV) without comorbid psychiatric problems and in 23 healthy controls aged 7 to 11 years. Children were on no medication, in good health and did not consume products containing caffeine ≥ 7 days prior to the polysomnography (PSG) study. PSG evaluation was performed at each child''s home; children slept in their regular beds and went to bed at their habitual bedtimes.

Measurements

Standard overnight multichannel PSG evaluation was performed using a portable polysomnography device. In addition, parents were asked to complete a sleep questionnaire.

Results:

Compared to controls, children in the ADHD group had significantly shorter duration of REM sleep, smaller percentage of total sleep time spent in REM sleep, and shorter sleep duration. In addition, the ADHD group had higher scores on the insufficient sleep and sleep anxiety factors than children in the control group.

Conclusions:

The present findings support the hypothesis that children with ADHD present sleep disturbances.

Citation:

Gruber R; Xi T; Frenette S; Robert M; Vannasinh P; Carrier J. Sleep disturbances in prepubertal children with attention deficit hyperactivity disorder: A home polysomnography study. SLEEP 2009;32(3):343-350.     

Changes of Heart Rate Variability during Methylphenidate Treatment in Attention-Deficit Hyperactivity Disorder Children: A 12-Week Prospective Study

Purpose

The aim of this study was to clarify the relationship between the autonomic nervous system and attention deficit hyperactivity disorder (ADHD) rating scales and to evaluate the usefulness of heart rate variability (HRV) as a psychophysiological biomarker for ADHD.

Materials and Methods

Subjects were recruited from outpatients in the Department of Child and Adolescent Psychiatry at the Korea University Medical Center from August 2007 to December 2010. Subjects received methylphenidate. Time- and frequency-domain analyses of HRV, the Korean ADHD rating scale (K-ARS), and computerized ADHD diagnostic system were evaluated before treatment. After a 12-week period of medication administration, we repeated the HRV measurements and K-ARS rating.

Results

Eighty-six subjects were initially enrolled and 37 participants completed the 12-week treatment and HRV measurements subsequent to the treatment. Significant correlations were found between the K-ARS inattention score and some HRV parameters. All of the HRV parameters, except the standard deviations of the normal-to-normal interval, very low frequency, and low frequency to high frequency, showed a significant positive correlation between baseline and endpoint measures in completers. High frequency (HF) and the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD), which are related to parasympathetic vagal tone, showed significant decreases from baseline to endpoint.

Conclusion

The HRV test was shown to be reproducible. The decrease in HF and RMSSD suggests that parasympathetic dominance in ADHD can be altered by methylphenidate treatment. It also shows the possibility that HRV parameters can be used as psychophysiological markers in the treatment of ADHD.     

Parent-reported symptoms of attention deficit hyperactivity disorder in children with intermittent exotropia before and after strabismus surgery

Purpose

To investigate the symptoms of attention deficit hyperactivity disorder (ADHD) as reported by parents in children with intermittent exotropia [X(T)] and to determine whether strabismus surgery for X(T) affects ADHD symptoms.

Materials and Methods

Fifty-one consecutive children undergoing muscle surgery for X(T) were prospectively recruited. One parent of each child completed the ADHD rating scale IV (ADHD RS-IV) assessment consecutively before and one year after surgery. Patients whose preoperative scores were above the cut-off point, the 90th percentile based on a Korean sample, were regarded as demonstrating the ADHD trait. The impact of muscle surgery on ADHD symptoms was assessed by comparing the preoperative scores with the post-operative scores.

Results

Eight (15.7%) of the 51 patients demonstrated the ADHD trait. ADHD RS-IV scores following strabismus surgery significantly decreased in patients with the ADHD trait (p=0.014), while they did not differ in patients without the ADHD trait. Seven (87.5%) of the 8 patients with the ADHD trait showed improvement in their ADHD RS-IV scores after surgery. There was no difference in surgical success rates between X(T) patients with and without the ADHD trait.

Conclusion

The ADHD trait was relatively common in children with X(T), and the parent-reported symptoms of the children with the ADHD trait improved after strabismus surgery. These results suggest that childhood X(T) may be one contributing factor to ADHD-related symptoms.     

Idiom Comprehension Deficits in High-Functioning Autism Spectrum Disorder Using a Korean Autism Social Language Task

Purpose

High-functioning autism spectrum disorder (ASD) involves pragmatic impairment of language skills. Among numerous tasks for assessing pragmatic linguistic skills, idioms are important to evaluating high-functioning ASD. Nevertheless, no assessment tool has been developed with specific consideration of Korean culture. Therefore, we designed the Korean Autism Social Language Task (KASLAT) to test idiom comprehension in ASD. The aim of the current study was to introduce this novel psychological tool and evaluate idiom comprehension deficits in high-functioning ASD.

Materials and Methods

The participants included 42 children, ages 6-11 years, who visited our child psychiatric clinic between April 2014 and May 2015. The ASD group comprised 16 children; the attention deficit hyperactivity disorder (ADHD) group consisted of 16 children. An additional 10 normal control children who had not been diagnosed with either disorder participated in this study. Idiom comprehension ability was assessed in these three groups using the KASLAT.

Results

Both ASD and ADHD groups had significantly lower scores on the matched and mismatched tasks, compared to the normal control children (matched tasks mean score: ASD 11.56, ADHD 11.56, normal control 14.30; mismatched tasks mean score: ASD 6.50, ADHD 4.31, normal control 11.30). However, no significant differences were found in scores of KASLAT between the ADHD and ASD groups.

Conclusion

These findings suggest that children with ASD exhibit greater impairment in idiom comprehension, compared to normal control children. The KASLAT may be useful in evaluating idiom comprehension ability.     

Prevalence and incidence of attention-deficit/hyperactivity disorder in Slovenian children and adolescents: a database study from a national perspective

Aim

To estimate prevalence and incidence of attention deficit hyperactivity disorder (ADHD) in children and adolescents in Slovenia using different epidemiological models.

Methods

Data from the National Institute of Public Health of the Republic of Slovenia for the period 1997-2012 were analyzed. The database includes the annual number of newly diagnosed outpatients with ADHD in Slovenia. The evaluation for ADHD diagnoses was done in accordance with the Tenth Revision of the International Classification of Diseases (ICD-10) outpatient data codes. In model 1, a linear increase was proposed to fit the data in the period from 1997 to 2003 in order to extrapolate the data before 1997. In model 2 and 3, an exponential increase in the annual incidence rate was proposed.

Results

The incidence rate of ADHD diagnosis in 1997 was 0.032% and in 2012 it increased to 0.082%. Mean prevalence rate was 750 (95% confidence interval: 660-840) per 100 000 children and adolescents. It was estimated that the prevalence rate in 2020 would be 1% (95% confidence interval: 0.875-1.125), which is 6.3-fold higher than in 1997.

Conclusions

ADHD is a common mental health disorder among Slovenian children and adolescents, but it remained underdiagnosed compared with Western countries. Our results indicated a need for improved timely interventions in Slovenia, not only in child and adolescent psychiatry but also in primary settings and adult psychiatry, where ADHD should be more efficiently recognized.Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in childhood and adolescence, characterized by developmentally inappropriate inattention, hyperactivity, and/or impulsivity (1). It entails economic costs, causes family stress and academic and vocational adversity, and has a negative effect on the patient’s self-esteem (2). Although it is seen as a problem that takes place predominantly in childhood and adolescence, clinical and epidemiological research has shown that in 30–50% of patients ADHD persists into adulthood (3,4).Children exhibiting symptoms of inattention, hyperactivity, and impulsivity have been described previously (5). In 1980, the third edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-III) introduced the term “ADD (Attention-Deficit Disorder) with or without hyperactivity.” DSM-III-R (1987) replaced this term by the term ADHD and DSM-IV presented the subtypes of ADHD (6-9).ADHD affects 3% to 9% of children worldwide (10). In European countries, it is identified as a hyperkinetic disorder according to the 10th Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) and in North America as ADHD (DSM-IV). DSM-IV criteria include a broader group of subjects than the ICD-10 criteria (11,12).While the popular press across Europe frequently comments on increased rates of ADHD diagnosis, questioning whether ADHD is overdiagnosed and overtreated, reviews of clinical practice suggest that in Europe ADHD is underdiagnosed and undertreated (13,14). ADHD is underdiagnosed especially in adults; which is why it is important to better understand the factors that contribute to accurate diagnosis (15). Diagnosis and management of ADHD include nonpharmacological treatment, including behavioral therapy, and pharmacological treatment with stimulants and nonstimulants (16). In many European countries including Slovenia, the incidence and prevalence of this disorder are not well researched. In Slovenia, there are also no national guidelines for ADHD treatment and diagnosis and no published data on the prevalence of ADHD (17,18). The primary aim of this study was to calculate the incidence and prevalence of ADHD diagnosis among children and adolescents in Slovenia in 2012, based on national data from 1997 to 2012. For this purpose, several different epidemiological models were developed. The secondary aim was to predict the number of Slovenian children and adolescents that will be diagnosed with ADHD in 2020.     

Protection of leukotriene receptor antagonist against aspirin-induced bronchospasm in asthmatics

Purpose

Leukotriene receptor antagonists (LTRAs) are used to treat aspirin-intolerant asthma (AIA); however, the protective effects of long-term LTRA administration against aspirin-induced bronchospasm have not been evaluated.

Objectives

We investigated the efficacy of a 12-week treatment with a LTRA in protecting against aspirin-induced asthma in AIA patients.

Methods

Fifty-two adult patients with AIA underwent an aspirin challenge test just before administration of montelukast (10 mg/day) and just after 12 weeks of treatment. The protective effect was assessed as the disappearance of aspirin-induced bronchospasm after 12 weeks of treatment. The results were compared according to the patients'' clinical and physiological parameters.

Results

The decline in FEV1 following aspirin challenge was significantly reduced from 28.6±1.9% to 10.2±1.7% (P=0.0001) after 12 weeks of montelukast treatment. However, 14 subjects (30%) still showed a positive response (>15% decline in FEV1) to aspirin challenge. Grouping the subjects into good and poor responders according to post-treatment responses revealed that the pretreatment aspirin-induced FEV1 decline was significantly greater in the poor responders and that the triggering dose of aspirin and the induction time for a positive response were lower and shorter, respectively, in the poor responders. Histories of aspirin hypersensitivity and sinusitis were more prevalent among the poor responders than among the good responders.

Conclusions

Twelve weeks of treatment with montelukast protected against aspirin-induced bronchospasm in 70% of the AIA cases. A poor response was associated with more severe aspirin-induced bronchospasms before treatment and a history of aspirin hypersensitivity or sinusitis.

Clinical implications

A severe response to aspirin challenge may be a predictor of poor responsiveness to leukotriene antagonist treatment.     

Behavioral Outcome Effects of Serious Gaming as an Adjunct to Treatment for Children With Attention-Deficit/Hyperactivity Disorder: A Randomized Controlled Trial

Background

The need for accessible and motivating treatment approaches within mental health has led to the development of an Internet-based serious game intervention (called “Plan-It Commander”) as an adjunct to treatment as usual for children with attention-deficit/hyperactivity disorder (ADHD).

Objective

The aim was to determine the effects of Plan-It Commander on daily life skills of children with ADHD in a multisite randomized controlled crossover open-label trial.

Methods

Participants (N=170) in this 20-week trial had a diagnosis of ADHD and ranged in age from 8 to 12 years (male: 80.6%, 137/170; female: 19.4%, 33/170). They were randomized to a serious game intervention group (group 1; n=88) or a treatment-as-usual crossover group (group 2; n=82). Participants randomized to group 1 received a serious game intervention in addition to treatment as usual for the first 10 weeks and then received treatment as usual for the next 10 weeks. Participants randomized to group 2 received treatment as usual for the first 10 weeks and crossed over to the serious game intervention in addition to treatment as usual for the subsequent 10 weeks. Primary (parent report) and secondary (parent, teacher, and child self-report) outcome measures were administered at baseline, 10 weeks, and 10-week follow-up.

Results

After 10 weeks, participants in group 1 compared to group 2 achieved significantly greater improvements on the primary outcome of time management skills (parent-reported; P=.004) and on secondary outcomes of the social skill of responsibility (parent-reported; P=.04), and working memory (parent-reported; P=.02). Parents and teachers reported that total social skills improved over time within groups, whereas effects on total social skills and teacher-reported planning/organizing skills were nonsignificant between groups. Within group 1, positive effects were maintained or further improved in the last 10 weeks of the study. Participants in group 2, who played the serious game during the second period of the study (weeks 10 to 20), improved on comparable domains of daily life functioning over time.

Conclusions

Plan-It Commander offers an effective therapeutic approach as an adjunct intervention to traditional therapeutic ADHD approaches that improve functional outcomes in daily life.

Trial Registration

International Standard Randomized Controlled Trial Number (ISRCTN): 62056259; http://www.controlled-trials.com/ISRCTN62056259 (Archived by WebCite at http://www.webcitation.org/6eNsiTDJV).     

The Variable Response-Stimulus Interval Effect and Sleep Deprivation: An Unexplored Aspect of Psychomotor Vigilance Task Performance

Study Objectives:

The Psychomotor Vigilance Task (PVT) contains variable response-stimulus intervals (RSI). Our goal is to investigate the effect of RSI on performance to determine whether sleep deprivation affects the ability to attend to events across seconds and whether this effect is independent of impairment in sustaining attention across minutes, as measured by time on task.

Design:

A control group following their normal sleep routines and 3 groups exposed to 54 hours of total sleep deprivation performed a 10-minute PVT every 6 hours for 9 total test runs.

Setting:

Sleep deprivation occurred in a sleep laboratory with continuous behavioral monitoring; the control group took the PVT at home.

Subjects:

Eighty-four healthy sleepers (68 sleep deprivation, 16 controls; 22 women; aged 18-35 years).

Measurements and Results:

Across groups, as the RSI increased from 2 to 10 seconds, mean RT was reduced by 69 milliseconds (main effect of RSI, P < 0.001). There was no interaction between the sleep deprivation and RSI effects. As expected, there was a significant interaction of sleep deprivation and time on task for mean RT (P = 0.002). Time on task and RSI effects were independent. Parallel analyses of percentage of lapses and percentage of false starts produced similar results.

Conclusions:

We demonstrate that the cognitive mechanism of attention responsible for response preparation across seconds is distinct from that for maintaining attention to task performance across minutes. Of these, only vigilance across minutes is degraded by sleep deprivation. Theories of sleep deprivation should consider how this pattern of spared and impaired aspects of attention may affect real-world performance.

Citation:

Tucker AM; Basner RC; Stern Y; Rakitin BC. The variable response-stimulus interval effect and sleep deprivation: an unexplored aspect of psychomotor vigilance task performance. SLEEP 2009;32(10):1393-1395.     

Heterozygosity for a protein truncation mutation of sodium channel SCN8A in a patient with cerebellar atrophy, ataxia, and mental retardation

Background

The SCN8A gene on chromosome 12q13 encodes the voltage gated sodium channel Na_v1.6, which is widely expressed in neurons of the CNS and PNS. Mutations in the mouse ortholog of SCN8A result in ataxia and other movement disorders.

Methods

We screened the 26 coding exons of SCN8A in 151 patients with inherited or sporadic ataxia.

Results

A 2 bp deletion in exon 24 was identified in a 9 year old boy with mental retardation, pancerebellar atrophy, and ataxia. This mutation, Pro1719ArgfsX6, introduces a translation termination codon into the pore loop of domain 4, resulting in removal of the C‐terminal cytoplasmic domain and predicted loss of channel function. Three additional heterozygotes in the family exhibit milder cognitive and behavioural deficits including attention deficit hyperactivity disorder (ADHD). No additional occurrences of this mutation were observed in 625 unrelated DNA samples (1250 chromosomes).

Conclusions

The phenotypes of the heterozygous individuals suggest that mutations in SCN8A may result in motor and cognitive deficits of variable expressivity, but the study was limited by lack of segregation in the small pedigree and incomplete information about family members. Identification of additional families will be required to confirm the contribution of the SCN8A mutation to the clinical features in ataxia, cognition and behaviour disorders.     

Response of patent medicine vendors in rural areas of Lagos state Nigeria to antimalarial policy change

Background

Patent medicine vendors (PMVs) play an important role in the treatment of malaria, especially in the rural areas. Nigeria recently changed her antimalarial treatment policy from chloroquine to artemisinin-based combination therapy (ACT).

Objectives

To determine the response of PMVs to the new policy.

Methods

A baseline study was conducted in two local government areas (LGAs) of Lagos state Nigeria as the first phase in an intervention study aimed at improving the malarial treatment practices of PMVs in rural Lagos. A mixed method design involving a questionnaire survey of 180 PMVs and four key informant interviews were used. An antimalarial drug (AMD) audit was also performed.

Results

More than 80% of respondents were aware of the policy change in malaria treatment, but only 23.9% sold an ACT for the last case of malaria treated in an under five child. The main determining factor of the particular AMD sold was PMV''s personal choice (70.6%). About half (58.9%) of the shops stocked ACTs, the newly recommended antimalarials.

Conclusions

The high awareness of the policy change did not translate to a commensurate increase in the sale of the new drugs. Factors beyond the PMVs need to be addressed for a successful adoption of the new policy.     

Circadian and Wake-Dependent Influences on Subjective Sleepiness,Cognitive Throughput,and Reaction Time Performance in Older and Young Adults

Study Objectives:

To assess circadian and homeostatic influences on subjective sleepiness and cognitive performance in older adults when sleep and waking are scheduled at different times of day; to assess changes in subjective sleepiness and cognitive performance across several weeks of an inpatient study; and to compare these findings with results from younger adults.

Design:

Three 24-h baseline days consisting of 16 h of wakefulness and an 8-h sleep opportunity followed by 3-beat cycles of a 20-h forced desynchrony (FD) condition; 18 20-h “days,” each consisting of 13.33 h of scheduled wakefulness and 6.67 h of scheduled sleep opportunity.

Setting:

Intensive Physiological Monitoring Unit of the Brigham and Women''s Hospital General Clinical Research Center.

Participants:

10 healthy older adults (age 64.00 ± 5.98 y, 5 females) and 10 healthy younger adults (age 24.50 ± 3.54 y, 5 females).

Interventions:

Wake episodes during FD scheduled to begin 4 h earlier each day allowing for data collection at a full range of circadian phases.

Measurements and Results:

Subjective sleepiness, cognitive throughput, and psychomotor vigilance assessed every 2 h throughout the study. Core body temperature (CBT) data collected throughout to assess circadian phase. Older subjects were less sleepy and performed significantly better on reaction time (RT) measures than younger subjects. Decrements among younger subjects increased in magnitude further into the experiment, while the performance of older subjects remained stable.

Conclusions:

Our findings demonstrate that the waking performance and alertness of healthy older subjects are less impacted by the cumulative effects of repeated exposure to adverse circadian phase than that of young adults. This suggests that there are age-related changes in the circadian promotion of alertness, in the wake-dependent decline of alertness, and/or in how these 2 regulatory systems interact in healthy aging.

Citation:

Silva EJ; Wang W; Ronda JM; Wyatt JK; Duffy JF. Circadian and wake-dependent influences on subjective sleepiness, cognitive throughput, and reaction time performance in older and young adults. SLEEP 2010;33(4):481-490.     

Testing association between LRRK2 and Parkinson's disease and investigating linkage disequilibrium

Background

We and others recently identified the gene underlying PARK8 linked Parkinson''s disease (PD). This gene, LRRK2, contains mutations that cause an autosomal dominant PD, including a mutation, G2019S, which is the most common PD causing mutation identified to date. Common genetic variability in genes that contain PD causing mutations has previously been implicated as a risk factor for typical sporadic disease.

Methods

We undertook a case‐control association analysis of LRRK2 in two independent European PD cohorts using 31 tagging single nucleotide polymorphisms (tSNPs) and five potentially functional SNPs. To assess the structure of this locus in different populations, we have performed linkage disequilibrium (LD) analysis using these variants in a human diversity panel.

Results

We show that common genetic variability in LRRK2 is not associated with risk for PD in the European populations studied here. We also show inter‐population variability in the strength of LD across this locus.

Conclusions

To our knowledge this is the first comprehensive analysis of common variability within LRRK2 as a risk factor for PD.     

Pilot Evaluation of a Novel Clinical Test of Reaction Time in National Collegiate Athletic Association Division I Football Players

Context:

Evidence suggests that concussion prolongs reaction time (RT). We have developed a simple, reliable clinical tool for measuring reaction time that may be of value in the assessment of concussion in athletes.

Objective:

To compare baseline values of clinical RT (RT_clin) obtained using the new clinical reaction time apparatus with computerized RT (RT_comp) obtained using a validated computerized neuropsychological test battery.

Design:

Cross-sectional study.

Setting:

Data were collected during a National Collegiate Athletic Association Division I collegiate football team''s preparticipation physical examination session.

Patients or Other Participants:

Ninety-four Division I collegiate football players.

Main Outcome Measure(s):

The RT_clin was measured using a 1.3-m measuring stick embedded in a weighted rubber disk that was released and caught as quickly as possible. The RT_comp was measured using the simple RT component of CogState Sport.

Results:

For the 68 athletes whose CogState Sport tests passed the program''s integrity check, RT_clin and RT_comp were correlated (r  =  0.445, P < .001). Overall, mean RT_clin was shorter and less variable than mean RT_comp (203 ± 20 milliseconds versus 268 ± 44 milliseconds; P < .001). When RT_clin and RT_comp were compared between those athletes with (n  =  68) and those without (n  =  26) valid CogState Sport test sessions, mean RT_clin was similar (202 ± 19 milliseconds versus 207 ± 23 milliseconds; P  =  .390), but mean RT_comp was different (258 ± 35 milliseconds versus 290 ± 55 milliseconds; P  =  .009).

Conclusions:

The RT_clin was positively correlated with RT_comp and yielded more consistent reaction time values during baseline testing. Given that RT_clin is easy to measure using simple, inexpensive equipment, further prospective study is warranted to determine its clinical utility in the assessment of concussion in athletes.     

Health literacy and task environment influence parents' burden for data entry on child-specific health information: randomized controlled trial

Background

Health care systems increasingly rely on patients’ data entry efforts to organize and assist in care delivery through health information exchange.

Objectives

We sought to determine (1) the variation in burden imposed on parents by data entry efforts across paper-based and computer-based environments, and (2) the impact, if any, of parents’ health literacy on the task burden.

Methods

We completed a randomized controlled trial of parent-completed data entry tasks. Parents of children with attention deficit hyperactivity disorder (ADHD) were randomized based on the Test of Functional Health Literacy in Adults (TOFHLA) to either a paper-based or computer-based environment for entry of health information on their children. The primary outcome was the National Aeronautics and Space Administration Task Load Index (TLX) total weighted score.

Results

We screened 271 parents: 194 (71.6%) were eligible, and 180 of these (92.8%) constituted the study cohort. We analyzed 90 participants from each arm. Parents who completed information tasks on paper reported a higher task burden than those who worked in the computer environment: mean (SD) TLX scores were 22.8 (20.6) for paper and 16.3 (16.1) for computer. Assignment to the paper environment conferred a significant risk of higher task burden (F_1,178 = 4.05, P = .046). Adequate literacy was associated with lower task burden (decrease in burden score of 1.15 SD, P = .003). After adjusting for relevant child and parent factors, parents’ TOFHLA score (beta = -.02, P = .02) and task environment (beta = .31, P = .03) remained significantly associated with task burden.

Conclusions

A tailored computer-based environment provided an improved task experience for data entry compared to the same tasks completed on paper. Health literacy was inversely related to task burden.

Trial registration

Clinicaltrials.gov NCT00543257; http://www.clinicaltrials.gov/ct2/show/NCT00543257 (Archived by WebCite at http://www.webcitation.org/5vUVH2DYR)     

Model-Based Assessment of Cardiovascular Autonomic Control in Children with Obstructive Sleep Apnea

Study Objectives:

To quantitatively assess daytime autonomic cardiovascular control in pediatric subjects with and without obstructive sleep apnea syndrome (OSAS).

Design:

Respiration, R-R intervals, and noninvasive continuous blood pressure were monitored in awake subjects in the supine and standing postures, as well as during cold face stimulation.

Setting:

Sleep disorders laboratory in a hospital setting.

Participants:

Ten pediatric patients (age 11.4 ± 3.6 years) with moderate to severe OSAS (obstructive apnea-hypopnea index = 21.0 ± 6.6/ h) before treatment and 10 age-matched normal control subjects (age 11.5 ± 3.7 years).

Measurements and Results:

Spectral analysis of heart rate variability revealed that high-frequency power was similar and the ratio of low- to high-frequency power was lower in subjects with OSAS vs control subjects. The closed-loop minimal model allowed heart rate variability to be partitioned into a component mediated by respiratory-cardiac coupling and a baroreflex component, whereas blood pressure variability was assumed to result from the direct effects of respiration and fluctuations in cardiac output. Baroreflex gain was lower in subjects with OSAS vs control subjects. Under orthostatic stress, respiratory-cardiac coupling gain decreased in both subject groups, but baroreflex gain decreased only in controls. The model was extended to incorporate time-varying parameter changes for analysis of the data collected during cold face stimulation: cardiac output gain increased in controls but remained unchanged in OSAS.

Conclusions:

Our findings suggest that vagal modulation of the heart remains relatively normal in pediatric subjects with OSAS. However, baseline cardiovascular sympathetic activity is elevated, and reactivity to autonomic challenges is impaired.

Citation:

Chaicharn J; Lin Z; Chen ML; Ward SLD; Keens T; Khoo MCK. Model-based assessment of cardiovascular autonomic control in children with obstructive sleep apnea. SLEEP 2009;32(7):927-938.     

Verifying appraisal evidence using feedback from trained peers: views and experiences of Scottish GP appraisers

Background

GP appraisal is currently considered inadequate because it lacks robustness. Objective assessment of appraisal evidence is needed to enable judgements on professional performance to be made.

Aim

To determine GP appraisers'' views of the acceptability, feasibility, and educational impact of external peer feedback received on three core appraisal activities undertaken as part of this study.

Design of study

Independent peer review and cross-sectional postal questionnaire study.

Setting

NHS Scotland.

Method

One of three core appraisal activities (criterion audit, significant event analysis, or video of consultations) was undertaken by GP appraisers and subjected to peer review by trained colleagues. A follow-up postal questionnaire elicited participants'' views on the potential acceptability, feasibility, and educational impact of this approach.

Results

Of 164 appraisers, 80 agreed to participate; 67/80 (84%) submitted one of three appraisal materials for peer review and returned completed questionnaires. For significant event analyses (n = 44), most responders believed the peer feedback method was feasible (100%) and fair (92.5%) and would add value to appraisal (95.5%). Peer feedback on criterion audits (n = 15) was believed to be acceptable and fair (93.3%) and it was thought it would be a useful educational tool (100%). Completing a consultation video (n = 8) was perceived to be feasible as part of normal general practice (n = 5). It was unanimously agreed that assessment of videos by peers has educational impact and would help improve appraisal.

Conclusion

This group of GP appraisers strongly supported the role of external and independent feedback by trained peers as one approach to strengthening the existing appraisal process.     

Prediction of Obstructive Sleep Apnea with Craniofacial Photographic Analysis

Study Objectives:

To develop models based on craniofacial photographic analysis for the prediction of obstructive sleep apnea (OSA).

Design:

Prospective cohort study.

Setting:

Sleep investigation unit in a university teaching hospital.

Patients:

One hundred eighty subjects (95.6% Caucasian) referred for the initial investigation of OSA were recruited consecutively.

Interventions:

Clinical assessment and frontal-profile craniofacial photographic analyses were performed prior to polysomnography. Prediction models for determining the presence of OSA (apnea-hypopnea index [AHI] ≥ 10) were developed using logistic regression analysis and classification and regression trees (CART).

Measurements and Results:

Obstructive sleep apnea was present in 63.3% of subjects. Using logistic regression, a model with 4 photographic measurements (face width, eye width, cervicomental angle, and mandibular length 1) correctly classified 76.1% of subjects with and without OSA (sensitivity 86.0%, specificity 59.1%, area under the receiver operating characteristics curve [AUC] 0.82). Combination of photographic and other clinical data improved the prediction (AUC 0.87), whereas prediction based on clinical assessment alone was lower (AUC 0.78). The optimal CART model provided a similar overall classification accuracy of 76.7%. Based on this model, 59.4% of the subjects were classified as either high or low risk with positive predictive value of 90.9% and negative predictive value of 94.7%, respectively. The remaining 40.6% of subjects have intermediate risk of OSA.

Conclusions:

Craniofacial photographic analysis provides detailed anatomical data useful in the prediction of OSA. This method allows OSA risk stratification by craniofacial morphological phenotypes.

Citation:

Lee RWW; Petocz P; Prvan T; Chan ASL; Grunstein RR; Cistulli PA. Prediction of obstructive sleep apnea with craniofacial photographic analysis. SLEEP 2009;32(1):46-52.     

The Effect of Posture on Cheyne-Stokes Respirations and Hemodynamics in Patients with Heart Failure

Study Objectives:

Cheyne-Stokes respirations occur in 40% of patients with heart failure. Orthopnea is a cardinal symptom of heart failure and may affect the patient''s sleeping angle. The objective of this study was to assess the respiratory and hemodynamic response to sleeping angle in a group of subjects with stable heart failure.

Design:

Twenty-five patients underwent overnight polysomnography with simultaneous and continuous impedance cardiographic monitoring. Sleeping polysomnographic and impedance cardiographic data were recorded.

Setting:

The study was conducted in a sleep center.

Patients:

All 25 patients had clinically stable heart failure and left ventricular ejection fractions < 40%.

Interventions:

The patients slept at 0°, 15°, 30°, and 45° in random order.

Measurements and Results:

Seventeen patients had Cheyne-Stokes apneas (index > 5/h) and 23 patients had hypopneas (index > 5/h). The hypopnea index showed no response to sleeping angle. The Cheyne-Stokes apnea index decreased with increasing sleeping angle (P < 0.001). This effect was seen only during supine sleep and non-rapid eye movement sleep and was absent in non-supine sleep, rapid eye movement sleep, and during periods of wakefulness. Thoracic fluid content index and left ventricular hemodynamics measured by impedance cardiography showed no response to sleeping angle.

Conclusions:

Changing the heart failure patient''s sleeping angle from 0° to 45° results in a significant decrease in Cheyne-Stokes apneas. This decrease occurs on a constant base of hypopneas. The changes in Cheyne-Stokes apneas are not related to changes in lung congestion and left ventricular hemodynamics.

Citation:

Soll BAG; Yeo KK; Davis JW; Seto TB; Schatz IJ; Shen EN. The effect of posture on Cheyne-Stokes respirations and hemodynamics in patients with heart failure. SLEEP 2009;32(11):1499-1506.