Mary L. Marzec

Effects of vagus nerve stimulation on respiration during sleep: a pilot study.

Background: Vagus nerve stimulation (VNS) is associated with respiratory effects such as hoarseness, dyspnea, and laryngeal irritation. The effects of VNS on sleep-related breathing in humans have not been reported previously. Methods: Four epilepsy patients underwent polysomnography (PSG) before and after 3 months of treatment with VNS. Two of the four patients also underwent follow-up PSG to assess the effects of changing stimulus parameters on sleep-related breathing. Results: All patients showed consistent sleep-related decreases in airflow and effort coinciding with VNS activation, although most events did not meet laboratory criteria for apneas or hypopneas. Apneas and hypopneas were more frequent during VNS activation than during nonactivation. Apnea–hypopnea index (AHI) for three subjects during VNS treatment PSG was <5 apneas and hypopneas/hour. In one patient with obstructive sleep apnea (OSA) before VNS treatment, AHI rose from 4 (pretreatment) to 11.3 (treatment). In this patient and in another patient without clinically significant OSA, lowering stimulus frequency, but not stimulus intensity, pulse width, or on-time, ameliorated VNS-related apneas and hypopneas. Conclusions: VNS is associated with adverse changes in respiration during sleep. In patients without preexisting OSA, this VNS effect is probably not clinically significant. In patients with preexisting OSA, VNS should be administered with care. Lowering VNS stimulus frequency or prolonging off-time may prevent exacerbation of OSA.

Vagus nerve stimulation reduces daytime sleepiness in epilepsy patients

Background: Given that vagal afferents project to brainstem regions that promote alertness, the authors tested the hypothesis that vagus nerve stimulation (VNS) would improve daytime sleepiness in patients with epilepsy. Methods: Sixteen subjects with medically refractory seizures underwent polysomnography and multiple sleep latency tests (MSLT) and completed the Epworth Sleepiness Scale (ESS), a measure of subjective daytime sleepiness, before and after 3 months of VNS. Most subjects (>80%) were maintained on constant doses of antiepileptic medications. Results: In the 15 subjects who completed baseline and treatment MSLT, the mean sleep latency (MSL) improved from 6.4 ± 4.1 minutes to 9.8 ± 5.8 minutes (± SD; p = 0.033), indicating reduced daytime sleepiness. All subjects with stimulus intensities of ≤1.5 mA showed improved MSL. In the 16 subjects who completed baseline and treatment ESS, the mean ESS score decreased from 7.2 ± 4.4 to 5.6 ± 4.5 points (p = 0.049). Improvements in MSLT and ESS were not correlated with reduction in seizure frequency. Sleep-onset REM periods occurred more frequently in treatment naps as compared to baseline naps (p < 0.008; Cochran-Mantel-Haenszel test). The amount of REM sleep or other sleep stages recorded on overnight polysomnography did not change with VNS treatment. Conclusions: Treatment with VNS at low stimulus intensities improves daytime sleepiness, even in subjects without reductions in seizure frequency. Daytime REM sleep is enhanced with VNS. These findings support the role of VNS in activating cholinergic and other brain regions that promote alertness.

Effects of Vagus Nerve Stimulation on Sleep-related Breathing in Epilepsy Patients

Summary:  Purpose: To describe the effects of vagus nerve stimulation (VNS) on sleep‐related breathing in a sample of 16 epilepsy patients.

Sleep staging and respiratory events in refractory epilepsy patients : Is there a first night effect?

Purpose:  We performed this analysis of possible first night effects (FNEs) on sleep and respiratory parameters in order to evaluate the need for two serial night polysomnograms (PSGs) to diagnose obstructive sleep apnea (OSA) in epilepsy patients.

Interictal epileptiform discharges do not change before seizures during sleep

Summary:  Purpose: Whether interictal epileptiform discharges (IEDs) increase, decrease, or are unchanged before epileptic seizures has implications for the pathophysiology of epilepsy. Prior studies relating IEDs and seizures have not demonstrated a change in IEDs before seizures. However, they have not controlled for changes in the depth of sleep. Our objective was to test the hypothesis that IEDs are related to seizures during sleep while adjusting for log delta power (LDP), a continuous measure of sleep depth.

Approaches to staging sleep in polysomnographic studies with epileptic activity

BACKGROUND The Standardized Sleep Manual of Rechtschaffen and Kales is well established and reliable in scoring the majority of polysomnograms (PSGs) encountered in clinical practice. In patients with epilepsy, however, abnormal brain activity may confound the interpretation of sleep waveforms. Our goal is to identify features that are problematic in analyzing sleep stages in patients with epilepsy and to offer approaches to score these PSGs. METHODS Ninety eight PSGs from 43 patients with epilepsy were scored using Rechtschaffen and Kales guidelines. Features interfering with sleep staging were noted. RESULTS In scoring polysomnograms (PSGs) of patients with epilepsy we noted epileptic seizures, interictal epileptiform discharges (IEDs) and abnormal EEG background to be features of epilepsy that compromised sleep scoring. Overall, 48% of the studies in our sample contained one or more of these epileptic features to the extent that sleep scoring by standard criteria was compromised. Approaches for staging sleep in the setting of these abnormalities are outlined. CONCLUSIONS The Rechtschaffen and Kales method of sleep scoring is useful in staging the majority of PSGs of patients with epilepsy. However, we advocate some modifications because the abnormal electrical activity of epilepsy may interfere with accurate scoring of sleep waveforms. These approaches to scoring PSGs of patients with epilepsy will require empirical testing.

Effects of environmentally‐focused interventions on health risks and absenteeism

Purpose – The purpose of this study is to determine results of an environmental approach to improving employee health status in a government employer setting.Design/methodology/approach – This is an observational study of one worksite and its employees from 2005 to 2007. Environmental interventions were part of the worksite environment, accessible, and applicable to employees regardless of health status. Outcomes were: change in the worksite environment using the Heart Check assessment, change in employee health risks using health risk appraisals (HRAs) and change in hours of sick time. The eligible population included active employees from 2005 to 2007 (n=2,276).Findings – The Heart Check score increased by 26 percentage points. Despite aging of HRA participants, results showed maintenance of risk status with a non‐significant increase in percent at low risk (51.6 percent to 53.1 percent). Percent at high risk had a non‐significant decrease (21.1 percent to 20.2 percent). The three‐month average for hour...

Development and Validity of a Scale to Measure Workplace Culture of Health

Objective: To describe the development of and test the validity and reliability of the Workplace Culture of Health (COH) scale. Methods: Exploratory factor analysis and confirmatory factor analysis were performed on data from a health care organization (N = 627). To verify the factor structure, confirmatory factor analysis was performed on a second data set from a medical equipment manufacturer (N = 226). Results: The COH scale included a structure of five orthogonal factors: senior leadership and polices, programs and rewards, quality assurance, supervisor support, and coworker support. With regard to construct validity (convergent and discriminant) and reliability, two different US companies showed the same factorial structure, satisfactory fit statistics, and suitable internal and external consistency. Conclusions: The COH scale represents a reliable and valid scale to assess the workplace environment and culture for supporting health.

Predictors of Behavior Change Intention Using Health Risk Appraisal Data

OBJECTIVES To investigate predictors of behavior change intention and discuss potential implications for practitioners. METHODS Health risk appraisal (HRA) data from 2 organizations were used to develop and confirm a path analysis model for predictors of intention to change behavior. RESULTS Lower self-rated health perception and higher ratings of stress corresponded to higher behavior-change intention scores. Stress was associated with poorer health perception. CONCLUSIONS Higher stress and lower perception of health status were directly associated with intention to change behavior. Incorporating stress management and awareness of health perception into health promotion strategies could enhance wellness programs by aligning programs with motivating factors.

Perceptions of a Culture of Health Implications for Communications and Programming

Purpose. This study aims to illustrate the potential utility of open-ended survey data, regarding faculty and staff perceptions of a culture of health (CoH), for targeting communications and programming. Overall, these types of data show how they may be used to assist in implementing, improving, and sustaining a CoH in an organization. Design/method/approach. An anonymous online questionnaire was sent to 10,000 employees. The analysis of open-ended responses was performed using the grounded theory approach. Emerging themes were organized into two major categories: favorable perceptions and unfavorable perceptions regarding the university’s CoH. Findings. These findings suggest that employees have specific favorable and unfavorable perceptions regarding their university’s CoH. Two main favorable perceptions that both faculty and staff commented on were (1) leaders/supervisors showing interest in health and well-being and (2) colleagues participating in healthful behaviors and setting good examples. Examples of unfavorable perceptions include stress not adequately addressed and healthy food options not readily available. Research limitations. The generalizability of the findings may be somewhat challenging given that the analyses are limited to individuals from a large Midwestern university. Also, given that this survey was voluntary, participants in the survey may possess unique characteristics that may have played a role in their likelihood to participate. Originality/value. There are few studies that address assessing a CoH in a university setting. This study provides examples of (1) topics to consider when evaluating an organization’s CoH and (2) actionable intervention and communication strategies that account for the employee’s perceptions. Others might use such examples when evaluating or preparing to assess their own organization’s CoH.