Mark S. Aloia

Neuropsychological sequelae of obstructive sleep apnea-hypopnea syndrome: A critical review

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a well-recognized clinical sleep disorder that results in chronically fragmented sleep and recurrent hypoxemia. The primary daytime sequelae of the disorder include patient reports of excessive daytime sleepiness, depression, and attention and concentration problems. It has been well established that OSAHS negatively impacts certain aspects of cognitive functioning. The primary goals of this article are to (1) clarify the pattern of cognitive deficits that are specific to OSAHS; (2) identify the specific cognitive domains that improve with treatment; and (3) elucidate the possible mechanisms of cognitive dysfunction in OSAHS. At the conclusion of the paper, we propose a potential neurofunctional theory to account for the etiology of cognitive deficits in OSAHS. Thirty-seven peer-reviewed articles were selected for this review. In general, findings were equivocal for most cognitive domains. Treatment, however, was noted to improve attention/vigilance in most studies and consistently did not improve constructional abilities or psychomotor functioning. The results are discussed in the context of a neurofunctional theory for the effects of OSAHS on the brain.

Neuropsychological changes and treatment compliance in older adults with sleep apnea

INTRODUCTION Apnea is a common disorder in older adults and has been shown to affect cognition. Some studies suggest that treatment for apnea improves certain cognitive deficits, but few studies have examined the relationship between compliance and cognitive improvement. We designed a study to answer the following questions about sleep apnea, cognition and treatment in older adults: (1) Which neuropsychological (NP) variables are differentially associated with measures of sleep fragmentation and oxygen desaturation? (2) Does compliant use of CPAP provide a cognitive advantage over noncompliant use? (3) Does NP performance at baseline predict compliance at 3 months? METHOD Twelve participants were recruited for the study. All had polysomnographically defined sleep apnea with an RDI of 10 or greater. All were also at least 55 years of age, had no other diagnosable sleep disorder and had no previous treatment for sleep apnea syndrome (SAS). Participants were administered a full NP battery before and 3 months after treatment with CPAP. RDI at baseline was associated with delayed verbal recall, while oxygen desaturation was associated with both delayed recall and constructional abilities. Compliant use of CPAP at 3 months was associated with greater improvements in attention, psychomotor speed, executive functioning and nonverbal delayed recall. Finally, attention measures predicted compliance at 3 months suggesting that those who were least vigilant at baseline were more likely to comply with treatment. DISCUSSION Results are discussed in terms of the relevance to targeting special populations for compliance interventions, the ways that treatment may specifically affect older adults and the possible dose-response relationship of CPAP.

Improving Compliance with Nasal CPAP and Vigilance in Older Adults with OSAHS

The present study examined the efficacy of a cognitive-behavioral intervention at improving compliance with CPAP and vigilance in older adults with obstructive sleep apnea/hypopnea syndrome (OSAHS). Participants included 12 subjects who were randomized into one of two groups controlling for age, education, disease severity, and vigilance. The experimental group received two 45-min sessions designed to educate subjects on the consequences of OSAHS and the efficacy of CPAP. The control group received the same extent of therapist contact but did not receive information on OSAHS or CPAP. All subjects were administered a test of vigilance both before and after the study. Compliance data were collected using CPAP devices with internal microprocessors at were read at 1, 4, and 12 weeks after treatment initiation. The results showed that the experimental condition did not enhance compliance after 1 week of treatment but did so by the 12-week follow-up. Subjects in the experimental condition had a run time of 3.2-h per night longer than did those in the control group. Those using CPAP more regularly at 12 weeks also showed greater improvement on vigilance at follow-up. Performance on vigilance testing before the introduction of CPAP was predictive of CPAP use at 12 weeks. In conclusion, a modest cognitive-behavioral intervention may substantially increase CPAP use and vigilance in older adults.

Neurocognitive functioning and improvement in quality of life following participation in cardiac rehabilitation

We investigated the relationship between neurocognitive functioning and quality of life/self-perceived health status (QOL) among cardiac rehabilitation (CR) patients to determine whether level of neurocognitive functioning is related to baseline QOL and improvement following CR. CR patients (n = 35) were given a neurocognitive screening before participation in CR, and also completed a behavioral inventory (SF-36) before and after CR to measure QOL associated with medical illness. At baseline, CR patients obtained relatively low SF-36 scores compared with published norms, and as reported previously, demonstrated inferior neurocognitive performance compared with healthy controls. Furthermore, neurocognitive performance was strongly positively correlated to SF-36 scores. Significant improvements were evident on many of the SF-36 subscales following rehabilitation. These improvements were relatively greater among SF-36 indexes of physical health status compared with SF-36 indexes of mental health status. Baseline neurocognitive performance also correlated strongly to the degree of improvement in SF-36 scores following rehabilitation. These findings indicate a strong relationship between baseline neurocognitive functioning and QOL before CR, and the degree to which QOL improves following this intervention.

Clinical Management of Poor Adherence to CPAP: Motivational Enhancement

Adherence to continuous positive airway pressure (CPAP) in patients with sleep apnea hypopnea syndrome (SAHS) is poor. Previous studies have attempted to identify specific barriers to treatment, but none has identified the sole cause for the problem. We outline a behavioral approach to the problem of CPAP adherence that is based on the theories of the transtheoretical model and social cognitive theory. We used these theories to guide the development of an intervention based on the methods of motivational interviewing. We present our motivational enhancement therapy for CPAP (ME-CPAP) here, with some brief pilot data to show its efficacy. Finally, we outline some strengths and weaknesses of taking a behavior change approach to the problem of poor CPAP adherence.

How early in treatment is PAP adherence established? Revisiting night-to-night variability

Obstructive sleep apnea (OSA) is a serious disorder with significant daytime consequences. Treatment for OSA most commonly takes the form of positive airway pressure (PAP). Although effective, PAP adherence is often below expectations. Previous studies have suggested that early PAP use can predict long-term adherence, but these studies have not been replicated, nor has follow up been longer than 3 months. This article presents a replication study enhanced by a longer follow up and additional data to suggest that 6-month adherence can be predicted within the first days of PAP use. This article also discusses how this might relate to the experience of significant side effects of treatment.

Neuropsychological Functioning Among Cardiac Rehabilitation Patients

PURPOSE The underlying pathophysiology contributing to coronary heart disease also predisposes patients to cerebrovascular disease and associated cognitive disorders. Although prior studies have focused on the neuropsychological sequelae of specific cardiac problems, few have examined the associated cognitive capacities and limitations of typical cardiac patients. The current study was designed to examine neuropsychological functioning among a sample of cardiac rehabilitation (CR) patients. METHODS Using neuropsychological instruments, patients were compared in a CR program to age-matched outpatient control subjects who had no known history of cardiac or neurologic disease. Cardiac rehabilitation patients were then divided into dichotomous subgroups based on whether they had undergone coronary artery bypass grafting, had experienced a myocardial infarction, had hypertension, or had impaired ejection fraction. Neuropsychological functioning was examined relative to each of these factors. RESULTS Cardiac rehabilitation patients had poorer neuropsychological test performance than did control subjects, with subtle relative deficits on measures of response generation, memory, and verbal abstraction, and particularly verbal fluency. Low ejection fraction, hypertension, and prior coronary artery bypass graft were associated with greater relative neuropsychological impairments. CONCLUSIONS Although CR patients were not grossly neuropsychologically impaired as a group, it appears highly likely that many within a given program exhibit some degree of neuropsychological dysfunction. Including neuropsychological screening as part of pre-CR testing would help to identify such patients. This information may help staff to impart health care information in a manner that is most effective for the individual patient and may also be useful in the formation of realistic goals.

Adherence to cognitive behavioral therapy for insomnia: A systematic review

Chronic insomnia is a significant public health problem worldwide, and insomnia has considerable personal and social costs associated with serious health conditions, greater healthcare utilization, work absenteeism, and motor-vehicle accidents. Cognitive behavioral therapy for insomnia (CBTI) is an efficacious treatment, yet attrition and suboptimal adherence may diminish its impact. Despite the increasing use of CBTI, surprisingly little attention has been devoted to understanding the role of adherence. This review describes a comprehensive literature search of adherence to CBTI. The search revealed 15 studies that evaluated adherence to CBTI in adults using valid and reliable measures of sleep, and measure of adherence other than study withdrawals. The primary purposes of this review were to 1) synthesize current study characteristics, methodology, adherence rates, contributing factors, and impact on outcomes, 2) discuss measurement issues, and 3) identify future practice and research directions that may lead to improved outcomes. Strong patterns and inconsistencies were identified among the studies, which complicate an evaluation of the role of adherence as a factor and outcome of CBTI success. The importance of standardized adherence and outcome measures is discussed. In light of the importance of adherence to behavior change, this systematic review may better inform future intervention efforts.

Brief Behavioral Therapies Reduce Early Positive Airway Pressure Discontinuation Rates in Sleep Apnea Syndrome: Preliminary Findings

Sleep apnea syndrome (SAS) is a serious disorder with significant daytime consequences. Treatment for SAS most commonly takes the form of positive airway pressure (PAP). Although effective, PAP adherence is often below expectations. Previous studies have suggested that the provision of information on the importance of PAP use can enhance adherence. In this study, we compare 2 brief behavioral approaches—traditional education (ED) and a motivational enhancement therapy (MET)—designed from theories of behavior change to standard clinical care. PAP discontinuation and adherence are the primary outcome measures. Both brief therapies decreased PAP discontinuation compared to standard care. The MET therapy performed best under the condition of flexible delivery of PAP, although differences were not statistically significant. Implications are discussed.

Sleep-disordered breathing and cognition in older adults.

Both sleep-disordered breathing (SDB) and cognitive impairment are common among older adults, yet few studies have examined their relationship within this population to determine whether the effect of SDB on cognition is of a magnitude similar to or greater than that observed in younger and middle-aged adults. Here, we review the extant literature and report that studies are largely supportive of an association between SDB and cognitive impairment in older adults, particularly in the domains of attention/vigilance, executive function, and verbal delayed recall memory. Presence of the APOE4 allele may confer increased vulnerability to SDB-associated cognitive dysfunction among elderly individuals. Although findings are mixed, there is strong evidence to suggest that SDB-related intermittent hypoxemia is the primary mechanism through which SDB exerts its adverse effects on cognition. We propose a microvascular model in which chronic intermittent hypoxemia causes vasculopathy that ultimately is expressed as cognitive impairment in the older adult. However, it remains unclear whether the effects of SDB on cognition are the same regardless of age or whether there is a synergistic interaction between age and SDB.