Sleep architecture is associated with core symptom severity in autism spectrum disorder

STUDY OBJECTIVES

While caregiver-reported sleep disturbances are common in children and adolescents with autism spectrum disorder (['), few studies have measured objective sleep in ASD compared to controls, and their findings are mixed. We investigated (1) differences in sleep architecture, specifically slow-wave sleep (SWS) and rapid eye movement (REM) sleep, between ASD and typically developing controls (TD); and (2) if any observed differences in sleep were associated with core ASD symptoms.

METHODS

We used ambulatory polysomnography (PSG) in 53 participants with ASD (ages 4-18) and 66 age-matched TD in their home sleeping environment. The primary outcome measures were SWS and REM sleep. Core behavioral ASD symptoms were assessed using the Autism Diagnostic Interview-Revised (ADI-R). Spectral power bands during sleep, and additional behavioral measures, were examined in exploratory analyses.

RESULTS

Compared to TD, participants with ASD exhibited a higher SWS ratio and lower REM sleep ratio. Within the ASD group, higher SWS was associated with more severe symptoms on the Restricted, Repetitive, and Stereotyped Behaviors subscale of the ADI-R. No association was observed between REM sleep ratio and any ASD symptom.

CONCLUSIONS

Increased SWS and reduced REM sleep ratio differentiated ASD from TD. However, only increased SWS was associated with more severe core ASD symptoms. Increased SWS may reflect neuronal immaturity specific to ASD in this age group. These findings may inform the underlying mechanisms of clinical symptoms observed in children and adolescents with ASD.

Individuals with Autism Spectrum Disorders Have Equal Success Rate But Require Longer Periods of Systematic Desensitization than Control Patients to Complete Ambulatory Polysomnography

STUDY OBJECTIVES

Polysomnography (PSG) is the gold standard for the assessment of sleep, yet the extensive apparatus required for monitoring with PSG can be difficult to tolerate, particularly in children. Clinical populations, such as those with anxiety or tactile sensitivity, may have even greater difficulty tolerating the PSG equipment. This study evaluated an innovative protocol for obtaining full PSG in individuals diagnosed autism spectrum disorders (ASD) or developmental delay (DD), as well as typically developing controls (TD). The primary aim was to assess whether this protocol was equally successful for obtaining PSG between these groups.

METHODS

One hundred sixty-one individuals were recruited for participation; 93 with a diagnosis of ASD, 23 with a diagnosis of DD, and 45 TD. The participants and families were instructed on a procedure of systematic desensitization to the ambulatory PSG equipment; PSG was performed in the home of the participant.

RESULTS

PSG was successfully attained in 144 (89.4%) participants. There was no difference in completion rate by diagnosis (p = 0.1), though younger age (p = 0.018) and duration of desensitization (p = 0.024) did predict PSG failure. Further, it was found that individuals with ASD took longer to desensitize to the equipment (16.08 d), than those with DD (8.04 d) or TD (0.98 d).

CONCLUSIONS

Systematic desensitization to PSG equipment, in combination with PSG completed in the home, allows for individuals with ASD to be equally successful in completing PSG, though they do take longer to acclimate to the equipment.

Impact of comorbid anxiety and depressive disorders on treatment response to cognitive behavior therapy for insomnia

OBJECTIVE

To evaluate the impact of comorbid anxiety or depressive disorders on treatment response to cognitive-behavior therapy (CBT) for insomnia, behavior therapy (BT), or cognitive therapy (CT).

METHOD

Participants were 188 adults (117 women; Mage = 47.4 years) with chronic insomnia, including 45 also presenting a comorbid anxiety or mild to moderate depressive disorder. They were randomized to BT (n = 63), CT (n = 65), or CBT (n = 60). Outcome measures were the proportion of treatment responders (decrease of ≥8 points on the Insomnia Severity Index; ISI) and remissions (ISI score < 8) and depression and anxiety symptoms.

RESULTS

Proportion of treatment responders and remitters in the CBT condition was not significantly different between the subgroups with and without comorbidity. However, the proportion of responders was lower in the comorbidity subgroup compared to those without comorbidity in both the BT (34.4% vs. 81.6%; p = .007) and CT (23.6% vs. 57.6%; p = .02) alone conditions, although remission rates and prepost ISI change scores were not. Pre to post change scores on the depression (-10.6 vs. -3.9; p < .001) and anxiety measures (-9.2 vs. -2.5; p = .01) were significantly greater in the comorbidity subgroup relative to the subgroup without comorbidity but only for those treated with the full CBT; no difference was found for those treated with either BT or CT alone.

CONCLUSIONS

The presence of a comorbid anxiety or mild to moderate depressive disorder did not reduce the efficacy of CBT for insomnia, but it did for its single BT and CT components when used alone. (PsycINFO Database Record

Hyperinsulinemic response to oral glucose challenge in individuals with posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with a 2-4 fold increased risk of developing Type 2 diabetes mellitus. However, detailed assessments of glucose metabolism and insulin secretion in a study designed to minimize confounders are lacking. Furthermore, few studies examine potential mechanisms involved. We analyzed data from a case-control study of medically healthy, medication-free adults to determine whether individuals with PTSD had abnormal glucose or insulin response to oral glucose tolerance test (OGTT) compared to controls. Secondarily, we assessed potential mediators such as sleep, cortisol and adiponectin.

METHODS

Data was analyzed from 92 age and gender-matched subjects (44 PTSD, 48 controls). Chronic PTSD was diagnosed using the Structured Clinical Interview for DSM-IV and Clinician Administered PTSD Scale. Subjects underwent 75-g OGTT, actigraphy and sleep diary (to quantify sleep duration), polysomnography (to assess slow wave sleep [SWS] and delta power), and overnight blood sampling (for cortisol and adiponectin).

RESULTS

At baseline, individuals with PTSD had mildly increased insulin levels (by 19%, compared to controls, p=0.048) that was mediated primarily by weight. In response to OGTT, the PTSD group had higher levels of insulin at 120 min (by 44%, p=0.03) and insulin AUC (by 43%, p=0.015) compared to controls, after adjusting for confounders. Glucose levels were similar in the two groups. Although self-reported sleep duration, SWS, and delta power differed between PTSD subjects and controls, they did not mediate the effects of PTSD status on insulin response.

CONCLUSION

In this case-control study, individuals with PTSD had a hyperinsulinemic response to oral glucose challenge compared to controls, suggestive of insulin resistance.

Comparative efficacy of behavior therapy, cognitive therapy, and cognitive behavior therapy for chronic insomnia: a randomized controlled trial

OBJECTIVE

To examine the unique contribution of behavior therapy (BT) and cognitive therapy (CT) relative to the full cognitive behavior therapy (CBT) for persistent insomnia.

METHOD

Participants were 188 adults (117 women; M age = 47.4 years, SD = 12.6) with persistent insomnia (average of 14.5 years duration). They were randomized to 8 weekly, individual sessions consisting of BT (n = 63), CT (n = 65), or CBT (n = 60).

RESULTS

Full CBT was associated with greatest improvements, the improvements associated with BT were faster but not as sustained and the improvements associated with CT were slower and sustained. The proportion of treatment responders was significantly higher in the CBT (67.3%) and BT (67.4%) relative to CT (42.4%) groups at post treatment, while 6 months later CT made significant further gains (62.3%), BT had significant loss (44.4%), and CBT retained its initial response (67.6%). Remission rates followed a similar trajectory, with higher remission rates at post treatment in CBT (57.3%) relative to CT (30.8%), with BT falling in between (39.4%); CT made further gains from post treatment to follow up (30.9% to 51.6%). All 3 therapies produced improvements of daytime functioning at both post treatment and follow up, with few differential changes across groups.

CONCLUSIONS

Full CBT is the treatment of choice. Both BT and CT are effective, with a more rapid effect for BT and a delayed action for CT. These different trajectories of changes provide unique insights into the process of behavior change via behavioral versus cognitive routes.

The relationship between body mass index and mental health among Iraq and Afghanistan veterans

BACKGROUND

Obesity is a growing public health concern and is becoming an epidemic among veterans in the post-deployment period.

OBJECTIVE

To explore the relationship between body mass index (BMI) and posttraumatic stress disorder (PTSD) in a large cohort of Iraq and Afghanistan veterans, and to evaluate trajectories of change in BMI over 3 years.

DESIGN

Retrospective, longitudinal cohort analysis of veterans' health records

PARTICIPANTS

A total of 496,722 veterans (59,790 female and 436,932 male veterans) whose height and weight were recorded at the Department of Veterans Affairs (VA) healthcare system at least once after the end of their last deployment and whose first post-deployment outpatient encounter at the VA was at least 1 year prior to the end of the study period (December 31, 2011).

MAIN MEASURES

BMI, mental health diagnoses.

KEY RESULTS

Seventy-five percent of Iraq and Afghanistan veterans were either overweight or obese at baseline. Four trajectories were observed: "stable overweight" represented the largest class; followed by "stable obese;" "overweight/obese gaining;" and "obese losing." During the 3-year ascertainment period, those with PTSD and depression in particular were at the greatest risk of being either obese without weight loss or overweight or obese and continuing to gain weight. Adjustment for demographics and antipsychotic medication attenuated the relationship between BMI and certain mental health diagnoses. Although BMI trajectories were similar in men and women, some gender differences were observed. For example, the risk of being in the persistently obese class in men was highest for those with PTSD, whereas for women, the risk was highest among those with depression.

CONCLUSIONS

The growing number of overweight or obese returning veterans is a concerning problem for clinicians who work with these patients. Successful intervention to reduce the prevalence of obesity will require integrated efforts from primary care and mental health to treat underlying mental health causes and assist with engagement in weight loss programs.

Electromyographic patterns suggest changes in motor unit physiology associated with early osteoarthritis of the knee

OBJECTIVE

To assess characteristics of active motor units (MUs) during volitional vastus medialis (VM) activation in adults with symptomatic knee osteoarthritis (OA) across the spectrum of radiographic severity and age-comparable healthy control volunteers.

METHODS

We evaluated 39 participants (age 65+/-3 years) in whom weight-bearing knee X-rays were assigned a Kellgren & Lawrence (KL) grade (18 with KL grade=0; four each with KL grades=1, 2 and 4; nine with grade 3). Electromyography (EMG) signals were simultaneously acquired using surface [surface EMG (S-EMG)] and intramuscular needle electrodes, and analyzed by decomposition-enhanced spike-triggered averaging to obtain estimates of size [surface-represented MU action potentials (S-MUAP) area], number [MU recruitment index (MURI)] and firing rates [MU firing rates (mFR)] of active MUs at 10%, 20%, 30% and 50% effort relative to maximum voluntary force [maximal voluntary isometric contraction (MVIC)] during isometric knee extension.

RESULTS

Knee extensor MVIC was lower in OA participants, especially at higher KL grades (P=0.05). Taking the observed force differences into account, OA was also associated with activation of larger MUs (S-MUAP area/MVICx%effort; P<0.0001). In contrast, the estimated number of active units (MURI/MVICx%effort) changed differently as effort increased from 10% to 50% and was higher with advanced OA (KL=3, 4) than controls (P=0.0002).

CONCLUSION

VM activation changes at the level of the MU with symptomatic knee OA, and this change is influenced by radiographic severity. Poor muscle quality may explain the pattern observed with higher KL grades, but alternative factors (e.g., nerve or joint injury, physical inactivity or muscle composition changes) should be examined in early OA.

Biased processing of emotional information in girls at risk for depression

Researchers have documented that children of depressed mothers are at elevated risk for developing a depressive disorder themselves. There is currently little understanding, however, of what factors place these children at elevated risk. In the present study, the authors investigated whether never-disordered daughters whose mothers have experienced recurrent episodes of depression during their daughters' lifetime are characterized by biased processing of emotional information. Following a negative mood induction, participants completed an emotional-faces dot-probe task. Daughters at elevated risk for depression, but not control daughters of never-disordered mothers, selectively attended to negative facial expressions. In contrast, only control daughters selectively attended to positive facial expressions. These results provide support for cognitive vulnerability models of depression.

Hormone replacement therapy and longitudinal changes in blood pressure in postmenopausal women

BACKGROUND

The incidence of hypertension in postmenopausal women exceeds that in age-matched men. Longitudinal studies relating hormone replacement therapy (HRT) to blood pressure changes are sparse.

OBJECTIVE

To investigate the association between HRT and longitudinal changes in blood pressure in postmenopausal women.

DESIGN

Longitudinal observational study.

SETTING

Community-dwelling volunteers.

PATIENTS

226 healthy, normotensive postmenopausal women from the Baltimore Longitudinal Study of Aging with a mean (+/-SD) age of 64 +/- 10 years were followed for 5.7 +/- 5.3 years. Seventy-seven women used both estrogen and progestin, and 149 used neither.

MEASUREMENTS

Lifestyle variables, blood pressure, and traditional cardiovascular risk factors were measured at baseline and approximately every 2 years thereafter.

RESULTS

Systolic blood pressure at baseline was similar in HRT users and nonusers (133.9 +/- 16.0 mm Hg vs. 132.4 +/- 14.8 mm Hg). Over time, average systolic blood pressure increased less in HRT users than nonusers, independent of other cardiovascular risk factors, physical activity, and alcohol use. For example, HRT users who were 55 years of age at their first Baltimore Longitudinal Study of Aging visit experienced a 7.6-mm Hg average increase in systolic blood pressure over 10 years; in contrast, the average increase in nonusers was 18.7 mm Hg. The lesser increase in systolic blood pressure in HRT users was more evident at older age. Diastolic blood pressure, which did not change statistically over time in either group, was not associated with HRT.

CONCLUSION

Postmenopausal women taking HRT have a smaller increase in systolic blood pressure over time than those not taking HRT. This difference is intensified at older ages.

Preliminary studies to develop a personal dosemeter for use by aircraft crew

This paper describes preliminary work to develop a cosmic-radiation dosemeter for use by military aircraft crew. The dosemeter is based on a combination of CR-39 etched-track detectors and TLD-700 thermoluminescent detectors. It is intended that the CR-39 be used to assess the neutron dose, while the TLD-700 is used to assess the photon and charged particle dose. The sensitivity of CR-39 to the neutron component of cosmic radiation was estimated by irradiating samples of the plastic at the CERN-CEC High Energy Reference Field Facility. This facility produced a radiation field with a neutron spectrum resembling that of the neutron component of cosmic radiation at typical airflight altitudes. The response of the CR-39 was linear over the range of doses studied (0.2-6.0 mSv) and there was no significant fading in the 6-month period after irradiation. The TLD-700 component of the dosemeter was calibrated using 137Cs gamma rays. The response of the TLD-700 was linear over the range of doses studied (0.01-5.0 mSv) with no significant fading in the 6-month period after irradiation. It was concluded that a combination of CR-39 and TLD-700 detectors would provide an effective cosmic-radiation dosemeter for use by military aircraft crew.

Accuracy of Doppler catheter measurements: effect of inhomogeneous beam power distribution on mean and peak velocity

OBJECTIVES

We sought to determine the effect of inhomogeneous distribution of beam power produced by Doppler catheters on measurements of mean and peak velocity of coronary blood flow.

BACKGROUND

Measurements of mean velocity of coronary blood flow by Doppler catheters have significant systematic errors that have not been completely characterized. We hypothesized that one error is the inhomogeneous distribution of the ultrasonic beam power and that this inhomogeneity makes measurements of mean, but not peak, velocity inaccurate.

METHODS

We constructed a scaled-up model of a Doppler catheter to allow for accurate measurement of the distribution of beam power by miniature hydrophones. This catheter was placed in a model of coronary blood flow in which the fluid velocity was accurately measured by an external laser Doppler velocimeter. The laser Doppler measurements of mean velocity were compared with the measurements of mean velocity made by the catheter, using fast Fourier transform analysis, both without and with correction for inhomogeneous beam power distribution. Peak velocity measurements were also compared, as predicted from theory, without the need of correction for inhomogeneous beam power distribution. To investigate the clinical relevance of our results, we conducted studies using a clinical Doppler catheter both in a scaled model of coronary flow and in a series of eight patients. In the model and in each patient, we rotated the catheter without changing the axial position to systematically alter the relation of the beam power distribution to the local fluid dynamics.

RESULTS

The measurement of beam power distribution revealed significant inhomogeneity. Comparison of the measured mean frequency shifts without correction for inhomogeneities in the distribution yielded a statistically significant difference. After correction for inhomogeneities, there was no statistically significant difference. Also, there was no significant difference for the peak frequency shifts. Rotation of the clinical catheter in the scaled model and in the patients changed the measured mean velocity (average change 18.8% and 20.6%, respectively), but not the measured peak velocity (average change 5.0% and 4.3%, respectively).

CONCLUSIONS

For signal analysis using a fast Fourier transform, the inhomogeneous distribution of power of the ultrasonic beam produced by Doppler catheters makes measurements of mean, but not peak, velocity inaccurate. Measurements of peak velocity may therefore prove superior to measurements of mean velocity in estimating the response to pharmacologic intervention and in estimating stenosis severity.

Cardiovascular assessment of the patient with renal problems

A focused cardiovascular system assessment of patients with renal problems is essential in determining an overall state of health. The patient history and physical examination are the primary components of assessment. This article reviews cardiovascular assessment specific to patients with renal problems. The assessment techniques of inspection, palpation, percussion and auscultation are presented. A variety of cardiovascular indicators are reviewed to assist in detecting abnormalities related to patients with renal problems.

The challenges of assessing skin indicators in people of color

Expert physical assessment skills are critical in the practice of home healthcare nursing. This article describes ways nurses can assess and document skin indicators in people of color that are meaningful to everyone involved in the patient's care.

Assessing ability to drive following an acute neurological event: are we on the right road?

Every day in Canada occupational therapists are asked to assess clients with neurological impairments and to provide recommendations to provincial licensing bureaus regarding the individual's fitness to drive. These decisions have great impact on the client and on society. In this paper we briefly review the findings that have been published regarding the assessment of individuals with neurological conditions who wish to resume driving. In addition, a description of the tools commonly used to assess individuals is provided, along with where available, the measurement properties of each. Finally, the Driving Evaluation Service of a physical rehabilitation centre is described.

Analysis of pulsed wave Doppler ultrasound spectra obtained from a model intracoronary catheter

Abnormal arterial blood flow patterns have been implicated in the evolution of various vascular disease processes. Intravascular ultrasound techniques using the pulsed wave Doppler catheter offer the opportunity to characterize these abnormal flow patterns. We have developed a mathematical model that predicts the first two moments of the Doppler spectrum obtained using a Doppler catheter based on the distribution of ultrasonic beam power and velocity profile of fluid flow with an arbitrary distribution of flow disturbances. A scaled-up, in vitro experimental arterial system was used to confirm the validity of the model. Comparison of the predicted first two moments of the Doppler spectrum to the experimental values in this system demonstrated that the distribution of beam power significantly affects the magnitude of the first two moments. Additionally, both velocity gradient and velocity fluctuation broadening effects play prominent roles in determining the magnitude of the second moment. These phenomena must therefore be considered when evaluating in vivo Doppler spectra used for the characterization of abnormal flow patterns.

Differentiation of abnormal blood flow patterns in coronary arteries based on Doppler catheter recordings

Abnormal arterial blood flow patterns have been implicated as etiologic factors in thrombosis and atherosclerosis. Intravascular pulsed Doppler ultrasound techniques with fast-Fourier transform analysis offer the opportunity to measure these abnormalities. The authors hypothesized that statistical analysis of radial-directed beam spectra could be used to distinguish disturbed from non-disturbed flow and that analysis of conventional axial-directed beam spectra could then be used to distinguish laminar high-shear from laminar low-shear flow. They developed a scaled-up in-vitro model of coronary flow consisting of a glycerol/H2O test fluid flowing through an acrylic cylinder at Reynolds numbers spanning the typical physiologic range within the coronary arteries. A scaled-up Doppler catheter with the capacity for 90 degrees reflection of the beam was placed centrally. Disturbed flow was created by introducing a flow screen, and altered shear rates were produced by changing the Reynolds number. For the radial-directed beam studies, the coefficients of variation of the Doppler spectra for the disturbed flow states were significantly greater than for the nondisturbed flow states (p less than 0.01). For the axial-directed beam studies, the coefficients of variation of the Doppler spectra for the laminar high-shear flow states were significantly greater than for the laminar low-shear flow states (p less than 0.01). They conclude that abnormal blood flow patterns can be differentiated by the selective use of radial-directed and axial-directed Doppler catheter recordings.

Wall shear stress distribution along the cusp of a tri-leaflet prosthetic valve

High levels of wall shear stress on the surface of valvular cusps can cause mechanical damage to the blood cells and the cusp surfaces. The shear stresses are also responsible for mechanical failure of prosthetic heart valves. Qualitative measurements of wall shear stress in the vicinity of the leaflets are thus essential for diagnosis of suspected complications and provide important information for the design and fabrication of bioprosthetic heart valves. For this purpose we measured the velocity distribution along the inside wall of the cusps of a tri-leaflet heart valve with a two colour laser Doppler anemometer system. The wall shear stresses on the cusp surface were computed and found to range from 80 to 120 N/m2 during the ejection phase. Wall shear stresses of up to 180 N/m2 were measured in loci of cusp flexure and the accelerated boundary layer. The results of this study show a correlation between the high shear stress loci and the clinically (animal) observed regions of cusp calcification.

The frequency response of electrochemical wall shear probes in pulsatile flow

The frequency response of surface-mounted electrochemical mass transfer probes used to deduce wall shear rates has been investigated experimentally for the case of fully developed laminar pulsatile flow in a straight tube. Generally good agreement is found with the asymptotic results obtained by Lighthill's methods. The significance of the results with regard to the investigation of models of pulsatile flows of physiological interest is discussed. It is concluded that the frequency-dependent phase and amplitude corrections required to obtain accurate wall shear measurements are of such magnitudes as to render impractical the use of electrochemical probes to determine wall shear rates in these flows.

Hydrophobic Grid Membrane Filter Method for Aerobic Plate Count in Foods: Collaborative Study

Twenty-one laboratories participated in a collaborative study to validate a hydrophobic grid membrane filter (HGMF) method for aerobic plate count by comparing its performance against the AOAC/APHA pour plate method. Raw milk, raw poultry, whole egg powder, flours, and spices were included in the study. Counts obtained by the HGMF and pour plate methods did not differ significantly, except in the case of whole egg powder, for which the HGMF method produced significantly higher counts. The hydrophobic grid membrane filter method for aerobic plate count in foods has been adopted official first action.