Relationship Between Obstructive Sleep Apnea Severity and Brain Activation During a Sustained Attention Task

Study Objectives:

The objectives of this study were to (1) characterize cognitive and cerebral correlates of attention and response speed in patients with obstructive sleep apnea (OSA) and (2) assess the association of performance and brain activation with measures of OSA severity.

Design:

Patients with OSA and controls were compared on performance and brain activation during a sustained attention task. The association of reaction time and brain activation with apnea-hypopnea index, nocturnal hypoxia, and arousals was assessed.

Setting:

Functional magnetic resonance imaging was conducted while participants performed a Go–No-Go task. The ‘Go’ trials of the Go–No-Go task were used to index attention processing.

Participants:

Fourteen patients with OSA and 14 normal control subjects with equivalent age, body mass index, blood pressure, and education.

Interventions:

N/A.

Measurements and Results:

Patients with OSA showed decreased brain activation in cingulate, frontal, and parietal regions typically involved in attention tasks, compared with control subjects. Within the patients with OSA, increasing arousal index, but not desaturation index, was associated with slower mean reaction time and with decreased brain activation in areas involved in arousal and attention, response selection, motor response, and decision making. The apnea-hypopnea index, by itself, was not associated with changes in cerebral response.

Conclusions:

Patients with OSA showed decreased brain activation compared with control subjects during an attention task. The association of arousal index (but not hypoxia) with slow reaction times and brain activation suggests that alertness and reaction times show greater correlations with measures of sleep disruption than with measures of hypoxia.

Citation:

Ayalon L; Ancoli-Israel S; Aka AA; McKenna BS; Drummond SPA. Relationship between obstructive sleep apnea severity and brain activation during a sustained attention task. SLEEP 2009;32(3):373–381.     

Effects of Sleep Deprivation on Dissociated Components of Executive Functioning

Study Objectives:

We studied the effects of sleep deprivation on executive functions using a task battery which included a modified Sternberg task, a probed recall task, and a phonemic verbal fluency task. These tasks were selected because they allow dissociation of some important executive processes from non-executive components of cognition.

Design:

Subjects were randomized to a total sleep deprivation condition or a control condition. Performance on the executive functions task battery was assessed at baseline, after 51 h of total sleep deprivation (or no sleep deprivation in the control group), and following 2 nights of recovery sleep, at fixed time of day (11:00). Performance was also measured repeatedly throughout the experiment on a control task battery, for which the effects of total sleep deprivation had been documented in previously published studies.

Setting:

Six consecutive days and nights in a controlled laboratory environment with continuous behavioral monitoring.

Participants:

Twenty-three healthy adults (age range 22–38 y; 11 women). Twelve subjects were randomized to the sleep deprivation condition; the others were controls.

Results:

Performance on the control task battery was considerably degraded during sleep deprivation. Overall performance on the modified Sternberg task also showed impairment during sleep deprivation, as compared to baseline and recovery and compared to controls. However, two dissociated components of executive functioning on this task—working memory scanning efficiency and resistance to proactive interference—were maintained at levels equivalent to baseline. On the probed recall task, resistance to proactive interference was also preserved. Executive aspects of performance on the phonemic verbal fluency task showed improvement during sleep deprivation, as did overall performance on this task.

Conclusion:

Sleep deprivation affected distinct components of cognitive processing differentially. Dissociated non-executive components of cognition in executive functions tasks were degraded by sleep deprivation, as was control task performance. However, the executive functions of working memory scanning efficiency and resistance to proactive interference were not significantly affected by sleep deprivation, nor were dissociated executive processes of phonemic verbal fluency performance. These results challenge the prevailing view that executive functions are especially vulnerable to sleep loss. Our findings also question the idea that impairment due to sleep deprivation is generic to cognitive processes subserved by attention.

Citation:

Tucker AM; Whitney P; Belenky G; Hinson JM; Van Dongen HPA. Effects of sleep deprivation on dissociated components of executive functioning. SLEEP 2010;33(1):47-57.     

Hypnotherapy: fact or fiction: a review in palliative care and opinions of health professionals

Context:

Complementary medicine like hypnotherapy is often used for pain and palliative care. Health professionals vary in views about hypnotherapy, its utility, value, and attitudes.

Aims:

To understand the opinions of health professionals on hypnotherapy.

Settings and Design:

A semi-qualitative method to survey opinions of the health professionals from various disciplines attending a programme on hypnotherapy was conducted.

Materials and Methods:

The survey form consisted of 32 statements about hypnosis and hypnotherapy. Participants were asked to indicate whether they agreed, disagreed, or were not sure about each statement. A qualitative feedback form was used to obtain further views about hypnotherapy.

Statistical Analysis Used:

Percentage, frequency distribution.

Results:

The sample consisted of 21 participants from various disciplines. Two-thirds of the participants gave correct responses to statements on dangerousness of hypnosis (90%), weak mind and hypnosis (86%), and hypnosis as therapy (81%). The participants gave incorrect responses about losing control in hypnosis (57%), hypnosis being in sleep (62%), and becoming dependent on hypnotist (62%). Participants were not sure if one could not hear the hypnotist one is not hypnotized (43%) about the responses on gender and hypnosis (38%), hypnosis leading to revealing secrets (23%).

Conclusions:

Despite patients using complementary medicine services, often health professionals are unaware of the issues associated with these services. These myths may interfere in using hypnotherapy as therapeutic tool in palliative care. It is important for health professionals to have an appropriate and evidence-based understanding about the complementary therapies including hypnotherapy.     

Acoustic analyses of diadochokinesis in fluent and stuttering children

OBJECTIVES:

The purpose of the study was to acoustically compare the performance of children who do and do not stutter on diadochokinesis tasks in terms of syllable duration, syllable periods, and peak intensity.

METHODS:

In this case-control study, acoustical analyses were performed on 26 children who stutter and 20 aged-matched normally fluent children (both groups stratified into preschoolers and school-aged children) during a diadochokinesis task: the repetition of articulatory segments through a task testing the ability to alternate movements. Speech fluency was assessed using the Fluency Profile and the Stuttering Severity Instrument.

RESULTS:

The children who stutter and those who do not did not significantly differ in terms of the acoustic patterns they produced in the diadochokinesis tasks. Significant differences were demonstrated between age groups independent of speech fluency. Overall, the preschoolers performed poorer. These results indicate that the observed differences are related to speech-motor age development and not to stuttering itself.

CONCLUSIONS:

Acoustic studies demonstrate that speech segment durations are most variable, both within and between subjects, during childhood and then gradually decrease to adult levels by the age of eleven to thirteen years. One possible explanation for the results of the present study is that children who stutter presented higher coefficients of variation to exploit the motor equivalence to achieve accurate sound production (i.e., the absence of speech disruptions).     

Balance performance with a cognitive task: a continuation of the dual-task testing paradigm

Context:

To ensure that concussed athletes return to play safely, we need better methods of measuring concussion severity and monitoring concussion resolution.

Objective:

To develop a dual-task model that assesses postural stability and cognitive processing in concussed athletes.

Design:

Repeated measures study.

Setting:

University laboratory.

Patients or Other Participants:

Twenty healthy, college-aged students (10 men, 10 women; age  =  20 ± 1.86 years, height  =  173 ± 4.10 cm, mass  =  71.83 + 35.77 kg).

Intervention(s):

Participants were tested individually in 2 sessions separated by 2 days. In one session, a balance task and a cognitive task were performed separately. In the other session, the balance and cognitive tasks were performed concurrently. The balance task consisted of 6 conditions of the Sensory Organization Test performed on the NeuroCom Smart Balance Master. The cognitive task consisted of an auditory switch task (3 trials per condition, 60 seconds per trial).

Main Outcome Measure(s):

For the balance test, scores for each Sensory Organization Test condition; the visual, vestibular, somatosensory, and visual-conflict subscores; and the composite balance score were calculated. For the cognitive task, response time and accuracy were measured.

Results:

Balance improved during 2 dual-task conditions: fixed support and fixed visual reference (t₁₈  =  −2.34, P < .05) and fixed support and sway visual reference (t₁₈  =  −2.72, P  =  .014). Participants'' response times were longer (F_1,18  =  67.77, P < .001, η²  =  0.79) and choice errors were more numerous under dual-task conditions than under single-task conditions (F_1,18  =  5.58, P  =  .03, η²  =  0.24). However, differences were observed only during category-switch trials.

Conclusions:

Balance was either maintained or improved under dual-task conditions. Thus, postural control took priority over cognitive processing when the tasks were performed concurrently. Furthermore, dual-task conditions can isolate specific mental processes that may be useful for evaluating concussed individuals.     

Level of knowledge about anaphylaxis and its management among health care providers

Objectives:

This study was conducted to assess the level of knowledge of health care providers regarding anaphylaxis and its management at a tertiary care teaching hospital.

Materials and Methods:

A pretested structured questionnaire was administered to interns, MBBS Phase II students, and nursing students. The subjects were asked to answer the questionnaire, which included questions regarding anaphylaxis and its management.

Results:

Of 265 subjects, 151 (56.9%) of subjects answered correctly that adrenaline is the first line of drug for the treatment of anaphylaxis. Among 151 subjects, 40 (26.4%) answered the correct dose of adrenaline, of which 25 (16.5%) subjects selected intramuscular injection as the most appropriate route of administration. Medical students'' performance was better than interns and nursing students on questions regarding dose, route, and site of adrenaline administration.

Conclusion:

Knowledge regarding the management of anaphylaxis was inadequate in almost all the health care providers who were included in the study. Improved education and training of health care providers are necessary for better management of anaphylaxis.     

Slow Wave Sleep and REM Sleep Awakenings Do Not Affect Sleep Dependent Memory Consolidation

Study Objectives:

The effects of REM sleep and slow wave sleep (SWS) deprivation on sleep-dependent motor and declarative memory consolidation.

Design:

Randomized, within-subject, cross-over study

Setting:

Weekly (women: monthly) sleep laboratory visits, with retest 60 hours later

Participants:

Twelve healthy subjects (6 men) aged between 20 and 30 years

Interventions:

REM sleep deprivation, SWS deprivation, or undisturbed sleep

Measurements and Results:

We deprived subjects once each of REM sleep and SWS, and once let them sleep undisturbed through the night. After each night, we tested declarative and procedural memory consolidation. We tested memory performance by a verbal paired associate task and a sequential finger-tapping task at 21:00 on the study night and again 60 hours later. Although REM sleep and SWS awakenings led to a significant reduction of the respective sleep stages, memory consolidation remained unaffected. We also found a significant correlation between the declarative task and sleep spindles in the undisturbed condition, especially the sleep spindles in the first third of the night.

Conclusion:

We suggest that word-pair learning relies on stage 2 sleep spindles and requires little SWS. Their sleep dependent consolidation is not affected by SWS deprivation. Simple motor tasks may either be consolidated in stage 2 sleep or depend on only small amounts of REM sleep. Their sleep dependent consolidation is not influenced by REM sleep deprivation.

Citation:

Genzel L; Dresler M; Wehrle R; Grözinger M; Steiger A. Slow wave sleep and REM sleep awakenings do not affect sleep dependent memory consolidation. SLEEP 2009;32(3):302–310.     

Cytokine profile in elderly patients with sepsis

Context:

Sepsis is a serious health problem in the elderly with a high degree of mortality. There is very limited data available in elderly subjects regarding the markers for sepsis. Development of good markers will help in overall management and prediction of sepsis.

Objectives:

Serial estimation of Interleukin-6 (IL-6) and Tumor Necrosis Factor-Alpha (TNF-α) and their correlation with mortality in sepsis in elderly patients and to determine the influence of gender on cytokine production and mortality in elderly patients with sepsis.

Settings and Design:

The prospective study was conducted at our tertiary care center from April 2007 to September 2008. Elderly Patients satisfying the Systemic Inflammatory Response Syndrome (SIRS) criteria were included.

Methods and Material:

TNF-α and IL-6 were estimated in 30 elderly patients admitted to our intensive care unit with SIRS and sepsis. The estimations were done on day 1, 3 and 7 of admission.

Statistical Analysis Used:

Student and paired ‘t’ tests, and ANOVA, which were further followed up by post-hoc ‘t’ tests with Bonferroni correction using SPSS.

Results:

Reducing levels of IL-6 levels from day 1 to 7 was found in the survivor group. TNF-α level was significantly low on day 1 in the nonsurvivor female group.

Conclusions:

Serial estimation of cytokines in elderly patients with sepsis will help in prediction of mortality. Female gender was an independent predictor of increased morality in critically ill patients with sepsis.     

Skeletal pattern in subjects with temporomandibular joint disorders

Introduction

To establish the skeletal pattern in subjects with malocclusions and temporomandibular disorders (TMD); to assess the relationship between craniofacial skeletal structures and TMD in subjects with malocclusions.

Material and methods

Sixty-four subjects with malocclusions, over 18 years of age, were included in the study. Temporomandibular disorders were clinically assessed according to the Helkimo Anamnestic Index. Subjects underwent a lateral cephalogram. Subjects were grouped according to the sagittal skeletal pattern (ANB angle) into class I, II and III. Parametric Student tests with equal or unequal variations were used (variations were previously tested with Levene test).

Results

Twenty-four patients with TMD (experimental sample); 40 patients without TMD (control group); interincisal angle was higher in class I and II (p < 0.05) experimental subjects; overjet was larger in experimental subjects; midline shift and Wits appraisal were broader in the experimental group in all three classes. In class III subjects, the SNB angle was higher in the experimental group (p = 0.01). Joint noises followed by reduced mandible mobility, muscular pain and temporomandibular joint (TMJ) pain were the most frequent symptoms in subjects with TMD and malocclusions.

Conclusions

Temporomandibular joint status is an important factor to consider when planning orthodontic treatment in patients with severe malocclusions; midline shift, large overjet and deep overbite have been associated with signs and symptoms of TMD.     

A systematic review evaluating the impact of task shifting on access to antiretroviral therapy in sub-Saharan Africa

Background

Task shifting, defined for this review as the shifting of ART initiation and management from physicians to nurses, has been proposed as a possible method to increase access to HIV treatment in Sub-Saharan Africa.

Objective

To critically evaluate the literature on task shifting, determining if there is evidence to support this view.

Methods

A systematic search of the literature was undertaken, with both peer reviewed publications and conference abstracts presenting original data eligible for inclusion. Studies were evaluated according to methodology and discussion of confounding factors.

Results

We identified 25 articles which evaluated the effect of task shifting on access to ART. The evidence was mixed. Although there is a significant body of field reports indicating that task shifting increases access, these studies were of low methodological quality. The only randomized controlled trial included in this review did not find that task shifting increased in access.

Conclusion

Task shifting appears to be most effective at increasing access when combined with other interventions and financial support. There is a need for more research into the effects of task shifting policies, especially randomized controlled trials and high quality cohort studies.     

A framework for characterizing eHealth literacy demands and barriers

Background

Consumer eHealth interventions are of a growing importance in the individual management of health and health behaviors. However, a range of access, resources, and skills barriers prevent health care consumers from fully engaging in and benefiting from the spectrum of eHealth interventions. Consumers may engage in a range of eHealth tasks, such as participating in health discussion forums and entering information into a personal health record. eHealth literacy names a set of skills and knowledge that are essential for productive interactions with technology-based health tools, such as proficiency in information retrieval strategies, and communicating health concepts effectively.

Objective

We propose a theoretical and methodological framework for characterizing complexity of eHealth tasks, which can be used to diagnose and describe literacy barriers and inform the development of solution strategies.

Methods

We adapted and integrated two existing theoretical models relevant to the analysis of eHealth literacy into a single framework to systematically categorize and describe task demands and user performance on tasks needed by health care consumers in the information age. The method derived from the framework is applied to (1) code task demands using a cognitive task analysis, and (2) code user performance on tasks. The framework and method are applied to the analysis of a Web-based consumer eHealth task with information-seeking and decision-making demands. We present the results from the in-depth analysis of the task performance of a single user as well as of 20 users on the same task to illustrate both the detailed analysis and the aggregate measures obtained and potential analyses that can be performed using this method.

Results

The analysis shows that the framework can be used to classify task demands as well as the barriers encountered in user performance of the tasks. Our approach can be used to (1) characterize the challenges confronted by participants in performing the tasks, (2) determine the extent to which application of the framework to the cognitive task analysis can predict and explain the problems encountered by participants, and (3) inform revisions to the framework to increase accuracy of predictions.

Conclusions

The results of this illustrative application suggest that the framework is useful for characterizing task complexity and for diagnosing and explaining barriers encountered in task completion. The framework and analytic approach can be a potentially powerful generative research platform to inform development of rigorous eHealth examination and design instruments, such as to assess eHealth competence, to design and evaluate consumer eHealth tools, and to develop an eHealth curriculum.     

Quantification of joint alignment and stability during a single leg stance task in a knee osteoarthritis cohort

Background

Knee osteoarthritis alters joint stability but its kinematics during functional weight-bearing tasks remain unclear. We propose and validate an assessment technique for the quantification of knee alignment and stability in patients during a short single leg stance task.

Does Pain Behavior Influence Assessment of Pain Severity?

Context:

Nurses are involved in assessment of pain in most clinical settings. Pain continues to be underestimated and undertreated.

Materials and Methods:

This study assessed the rating of pain severity by nurses who observed the two case scenarios using role plays. The data were computed and frequency distribution was derived.

Results:

Majority of the nurses underrated the pain and based their ratings on various factors.

Conclusions:

It is important to increase the awareness among nurses about comprehensive assessment of pain for better management.     

Significance of serum procalcitonin in sepsis

Context:

Rapid treatment of sepsis is of crucial importance for survival of patients. Specific and rapid markers of bacterial infection have been sought for early diagnosis of sepsis. One such measurement, Procalcitonin (PCT), has recently become of interest as a possible marker of the systemic inflammatory response to infection.

Aims:

This study was done to find out the common sources of sepsis and to evaluate the diagnostic value of PCT, its predictive value and its relation with Sepsis-related Organ Failure Assessment (SOFA) scores and mortality in various stages of sepsis.

Settings and Design:

The prospective study was conducted at our tertiary care center from October 2006 to December 2008. A total of 100 patients were included in the study. The study sample included all patients aged above 18 years presenting consecutively to our center during the study period with acute sepsis. They were divided into three groups: sepsis, severe sepsis and septic shockbased on standardized criteria.

Materials and Methods:

PCT and various other relevant factors were measured in all study subjects. These parameters were compared among the three study groups. The statistical analyses were done using Student “t” test and two-way analysis of variance (ANOVA).

Results:

Respiratory tract infection was the most common source of sepsis. PCT proved to be an excellent indicator of sepsis with sensitivity of 94%. There was a significant association between serum PCT and SOFA scores (P < 0.05). Serum PCT levels did not predict mortality in the present study.

Conclusions:

PCT is among the most promising sepsis markers, capable of complementing clinical signs and routine lab parameters suggestive of severe infection.     

Comparison of post-operative ICU sedation between dexmedetomidine and propofol in Indian population

Context:

Critically ill patients requiring mechanical ventilation frequently need sedatives and analgesics to facilitate their care. Dexmedetomidine, a short-acting alpha-2-agonist, possesses anxiolytic, anesthetic, hypnotic, and analgesic properties.

Aims:

The objective of this study was to evaluate the efficacy and safety of dexmedetomidine in comparison to propofol in the management of sedation for post-operative intensive care unit (ICU) patients, as a sedative agent.

Settings and Design:

Teaching hospital, A phase III, prospective, open, randomized and comparative.

Materials and Methods:

Thirty patients who were ambulatory and who required the post-operative mechanical ventilation or post-operative sedation were enrolled, in which 15 patients received Dexmedetomidine and remaining 15 patients received propofol. All these patients were treated for the period of 8 to 24 h.

Statistical Analysis Used:

Data were analyzed using Student''s t-test and Chi-square test. The value of P < 0.05 was considered as statistically significant.

Results:

Demographic data were comparable. Pulse rate, respiratory rate and blood pressure were comparable. Depth of sedation and extubation time were similar. To maintain analgesia throughout the study period, patients receiving propofol infusions required significantly more analgesics than patients receiving Dexmedetomidine.

Conclusions:

Dexmedetomidine appears to be a safe and acceptable ICU sedative agent when both the clinician''s and patient''s perspectives are considered.