The hypocretin neurotransmission system in myotonic dystrophy type 1

BACKGROUND

Patients with myotonic dystrophy type 1 (DM1) frequently have symptoms of excessive daytime sleepiness (EDS). Some patients with DM1 show sleep-onset REM, similar to that observed in narcolepsy. Narcolepsy is characterized by impaired hypocretin (Hcrt) neurotransmission.

OBJECTIVE

To test for dysregulation of Hcrt neurotransmission in a prospective cohort of patients with DM1.

METHODS

Hcrt levels in CSF were measured by radioimmunoassay. Sleep physiology was assessed by overnight polysomnography (PSG) and a multiple sleep latency test (MSLT). Splicing of Hcrt receptor 1 and 2 (HcrtR1 and HcrtR2) mRNA was examined in postmortem samples of temporal cortex.

RESULTS

Seventeen of 38 patients with DM1 reported symptoms of EDS. Among patients with DM1 with EDS who underwent PSG/MSLT, 7 of 13 showed reduced sleep latency, sleep-onset REM, or both. However, CSF Hcrt levels in DM1 (mean 277 pg/mL, n = 38) were not different from controls (mean 277 pg/mL, n = 33). Also, splicing of HcrtR1 and HcrtR2 mRNA in patients with DM1 was similar to controls.

CONCLUSIONS

Excessive daytime sleepiness and dysregulation of REM sleep occur frequently in patients with myotonic dystrophy type 1 (DM1). However, the pathophysiologic basis is distinct from narcolepsy, as patients with DM1 do not have a consistent defect of Hcrt release or receptor splicing.

Discrepancy between subjective symptomatology and objective neuropsychological performance in insomnia

STUDY OBJECTIVES

While daytime impairment is a defining feature of primary insomnia (PI), prior research using objective measures has not yielded clear and reliable evidence of global or specific deficits. In this investigation subjective and neuropsychological measures of daytime impairment were concurrently evaluated in subjects with primary insomnia (PIs) and in healthy good sleeper subjects (GSs). The goals for the study were to assess (1) whether PIs differ from GSs on subjective and/or objective measures and (2) the extent to which subjective and objective measures provide discordant information.

DESIGN

Subjects were evaluated on multiple self-report measures of sleep and daytime performance and were administered a comprehensive set of neuropsychological tests.

SETTING

The University of Rochester Sleep and Neurophysiology Research Laboratory (Rochester, NY).

PATIENTS OR PARTICIPANTS

Forty-nine subjects (32 PIs and 17 GSs). Seventy-one percent of the sample was female; average age 39 +/- 11 yrs.

RESULTS

Overall, PIs reported worse sleep, diminished activity levels, and a greater number and severity of daytime complaints. However, PIs did not show deficits on neuropsychological tests. Additionally, neuropsychological measures were not associated with severity of daytime complaints. Objectively measured sleep was found to be associated with performance (motor speed), while prospective and objective sleep measures were associated with level of daytime complaint.

CONCLUSIONS

The discrepancy between subjective daytime complaints and objective performance in individuals with insomnia is common, but poorly understood. This discordance may suggest that daytime impairment corresponds less to "output" and more to attentional bias or to the realistic appraisal that "effort" is required to maintain normal performance.

Chronic insomnia and MRI-measured hippocampal volumes: a pilot study

STUDY OBJECTIVES

Morphometric analysis of magnetic resonance imaging brain scans was used to investigate possible neuroanatomic differences between patients with primary insomnia compared to good sleepers.

DESIGN

MRI images (1.5 Tesla) of the brain were obtained from insomnia patients and good sleepers. MRI scans were analyzed bilaterally by manual morphometry for different brain areas including hippocampus, amygdala, anterior cingulate, orbitofron-tal and dorsolateral prefrontal cortex.

SETTING

University Hospital Sleep Center and Radiology Department

PARTICIPANTS

8 unmedicated physician-referred patients with chronic primary insomnia (3 males, 5 females; 48.4 + 16.3 years) and 8 good sleepers matched for age, sex, body mass index, and education.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Patients with primary insomnia demonstrated significantly reduced hippocampal volumes bilaterally compared to the good sleepers. None of the other regions of interest analyzed revealed differences between the 2 groups.

CONCLUSIONS

These pilot data raise the possibility that chronic insomnia is associated with alterations in brain structure. Replication of the findings in larger samples is needed to confirm the validity of the data. The integration of structural, neuropsychological, neuroendocrine and polysomnographic studies is necessary to further assess the relationships between insomnia and brain function and structure.

Cancer‐Related Fatigue and Sleep Disorders

Sleep disorders, such as difficulty falling asleep, problems maintaining sleep, poor sleep efficiency, early awakening, and excessive daytime sleepiness, are prevalent in patients with cancer. Such problems can become chronic in some patients, persisting for many months or years after completion of cancer therapy. For patients with cancer, sleep is potentially affected by a variety of factors, including the biochemical changes associated with the process of neoplastic growth and anticancer treatments, and symptoms that frequently accompany cancer, such as pain, fatigue, and depression. Fatigue is highly prevalent and persistent in patients with cancer and cancer survivors. Although cancer-related fatigue and cancer-related sleep disorders are distinct, a strong interrelationship exists between these symptoms, and a strong possibility exists that they may be reciprocally related. The majority of studies that have assessed both sleep and fatigue in patients with cancer provide evidence supporting a strong correlation between cancer-related fatigue and various sleep parameters, including poor sleep quality, disrupted initiation and maintenance of sleep, nighttime awakening, restless sleep, and excessive daytime sleepiness. This paper reviews the data from these studies with a view toward suggesting further research that could advance our scientific understanding both of potential interrelationships between sleep disturbance and cancer-related fatigue and of clinical interventions to help with both fatigue and sleep disturbance. Disclosure of potential conflicts of interest is found at the end of this article.

Do patients with sleep maintenance insomnia have a problem with sleep maintenance?

Do patients with primary insomnia differ from good sleepers with respect to the number or duration of awakenings or to the stages from which awakenings occur? To address this question, polysomnography (PSG) records were evaluated in 10 good sleepers (GS) and 10 primary insomnia patients (PI). PSG records were evaluated for occurrence and duration of awakenings and for the stage immediately preceding each awakening. PIs woke more frequently and for longer durations than did GSs. PIs' awakenings tended to occur from Stages 1 or 2; GSs' occurred from epochs scored as movement times. The data from this study represent the first attempt to characterize the stages from which awakenings occur in sleep maintenance insomnia.

A longitudinal study of depression, pain, and stress as predictors of sleep disturbance among women with metastatic breast cancer

OBJECTIVE

Sleep disturbances are common among women with breast cancer and can have serious consequences. The present study examined depression, pain, life stress, and participation in group therapy in relation to sleep disturbances in a sample of women with metastatic breast cancer.

METHODS

Ninety-three women with metastatic breast cancer participated in a large intervention trial examining the effect of the group therapy on their symptoms. They completed measures of depression, pain, life stress, and sleep disturbance at baseline, 4, 8 and 12 months.

RESULTS

The results showed that higher initial levels of depression at baseline predicted problems associated with getting up in the morning, waking up during the night, and daytime sleepiness. Increases in depression over the course of 12 months were associated with fewer hours of sleep, more problems with waking up during the night and more daytime sleepiness. Higher levels of pain at baseline predicted more problems getting to sleep. Increases in pain predicted more difficulty getting to sleep and more problems waking up during the night. Greater life stress at baseline predicted more problems getting to sleep and more daytime sleepiness.

CONCLUSIONS

Depression, pain, and life stress scores were each associated with different types of negative change in self-reported sleep disturbances. Depression, especially worsening depression, was associated with the greatest number of types of negative change. The relationships found between sleep disturbance and depression, pain, and life stress suggest specific ways to address the problem of sleep disturbance for women with metastatic breast cancer and show how different types of disturbed sleep may be clinical markers for depression, pain, or life stress in this population.

Insomnia as a risk factor for onset of depression in the elderly

There are at least 9 studies that provide evidence that insomnia is a significant risk factor for recurrent and new onset major depressive disorder (MDD), two of which suggest that this association also exists specifically for the elderly. In this study, archival data from a community sample of healthy elderly participants were used to assess the extent to which insomnia predicts future illness in this age cohort. Out of the 147 participants with no prior history of mental illness, 66 participants were classified as having no insomnia, 47 had indeterminate insomnia, and 34 had persistent insomnia. Twelve participants developed MDD during the 1-year follow-up period. Two had no insomnia, 4 had indeterminate insomnia, and 6 had persistent insomnia. Persistent insomnia with onset of depression occurred only in female participants and was significantly associated with middle insomnia. These data suggest that elderly participants with persistent insomnia are at greater risk for the development of new onset depression.

Who is a candidate for cognitive-behavioral therapy for insomnia?

Chronic insomnia impacts 1 in 10 adults and is linked to accidents, decreased quality of life, diminished work productivity, and increased long-term risk for medical and psychiatric diseases such as diabetes and depression. Recent National Institutes of Health consensus statements and the American Academy of Sleep Medicine's Practice Parameters recommend that cognitive-behavioral therapy for insomnia (CBT-I) be considered the 1st line treatment for chronic primary insomnia. Growing research also supports the extension of CBT-I for patients with persistent insomnia occurring within the context of medical and psychiatric comorbidity. In the emerging field of behavioral sleep medicine, there has yet to be a consensus point of view about who is an appropriate candidate for CBT-I and how this determination is made. This report briefly summarizes these issues, including a discussion of potential contraindications, and provides a schematic decision-to-treat algorithm.

Sleep homeostasis in primary insomnia

Three main factors, hyperarousal, circadian dysrhythmia, and homeostatic dysregulation, are thought to underlie chronic insomnia. To date, most of the empirical work has focused on the issue of hyperarousal and very little work has been undertaken on the issue of sleep homeostasis. In the present paper, we review the five lines of evidence which may be used to support the proposition that sleep homeostasis is altered in Primary Insomnia. These include findings pertaining to Slow Wave Sleep density, level of daytime sleepiness, sleepiness following sleep deprivation, recovery sleep following sleep deprivation, and response to sleep restriction therapy. In addition, we provide a discussion regarding how hyperarousal and circadian factors may interact with altered sleep homeostasis, and suggestions for further inquiry.

Placebo effects in primary insomnia

Placebo effects are commonly observed in insomnia clinical trials. With the advent of longer-term trials, such effects appear to be remarkably robust and durable. In this paper we review the classic factors that are believed to contribute to placebo effects and how these factors operate in insomnia randomized clinical trials. Beyond this we suggest that the episodic nature of insomnia may interact with patient preferences for intermittent dosing in such a way as to sustain placebo effects in the long term. An appreciation of the latter phenomenon may provide increased power to detect therapeutic outcomes and may be used to potentiate clinical gains.

A comparison of placebo and no-treatment during a hypnotic clinical trial

OBJECTIVE

Sleep parameters commonly improve during placebo treatment in insomnia clinical trials. We examined whether the improvement seen with placebo was related to taking pills or other non-specific factors.

METHOD

95 insomniacs took either a placebo pill (pill+) or no pill (pill-) on nights of their choosing over 12 weeks.

RESULTS

Pills were consumed on about half of the nights. Consistent improvement was seen with reduced reported sleep latency, wakefulness after sleep onset, number of awakenings, and total sleep time over the 12 weeks for both the pill+ and pill condition. A difference between pill+ and pill- was detected only for total sleep time, and this difference favored pill+.

CONCLUSIONS

This study suggests that improvement seen during placebo treatment is more related to non-specific factors of participating in clinical trial than to pill taking behavior.

Meteorologic factors and subjective sleep continuity: a preliminary evaluation

Little research has been undertaken to evaluate whether environmental factors other than bright light influence the individual's ability to initiate and maintain sleep. In the present analyses, nine meteorologic variables were evaluated for their possible relationship to self-reported sleep continuity in a sample of 43 subjects over a period of 105 days. In this preliminary analysis, high barometric pressure, low precipitation, and lower temperatures were significantly correlated with good sleep continuity. Interestingly, ambient light and lunar phase were not found to be strongly associated sleep diary measures.

The effects of modafinil and cognitive behavior therapy on sleep continuity in patients with primary insomnia

BACKGROUND

Daytime fatigue, if not frank sleepiness, is a common symptom among patients with insomnia, one that is exacerbated during acute treatment with cognitive behavior therapy (CBT). The present study was undertaken to assess whether modafinil could be used to reduce daytime fatigue, sleepiness, or both in patients with primary insomnia and whether the pharmacologic augmentation of wakefulness might produce improved sleep by itself or in combination with CBT.

METHODS

30 subjects with primary insomnia were enrolled in this study and were randomly assigned to 1 of 3 treatment conditions: (1) placebo plus CBT, (2) 100 mg modafinil plus CBT, or (3) 100 mg modafinil plus a contact control (monitor-only condition). Subjects were continuously monitored with sleep diaries from study intake until study end (10 weeks) and were evaluated on a weekly basis for changes in sleepiness.

RESULTS

The mean age of the group was 41.3 years (SD, 13.4), and 70.4% of subjects were women. All 3 groups exhibited mean sleep latency and wake after sleep-onset times that were more than 30 minutes in duration. The mean pretreatment sleep profiles did not significantly differ. Modafinil, when administered alone, did not significantly affect the patients' sleep profiles. A trend, however, was evident for improved sleep latency. Modafinil, as an adjunct to CBT, tended to (1) reduce daytime sleepiness as measured by the Epworth Sleepiness Scale and (2) enhance compliance with CBT. With respect to the latter, subjects in the modafinil plus CBT group more reliably adhered to the prescribed phase delay in bedtime than did the placebo plus CBT group.

DISCUSSION

These data suggest that modafinil may be used to diminish the negative side effects of CBT (increased daytime sleepiness) and may increase subject compliance with therapy. Whether enhanced daytime function mediates the change in adherence and whether reduced sleepiness and enhanced compliance translate to less patient attrition in the clinical setting remain to be evaluated.

Functional imaging of the sleeping brain: review of findings and implications for the study of insomnia

Despite the growing literature indicating that insomnia is prevalent and a substantial risk factor for medical and psychiatric morbidity, the pathophysiology of both Primary and Secondary Insomnia is poorly understood. Multiple trait and state factors are thought to give rise to and/or moderate illness severity in insomnia, but 'hyperarousal' is widely believed to be the final common pathway of the disorder. To date, very little work has been undertaken using functional imaging to explore the CNS correlates, underpinnings, or consequences of hyperarousal as it occurs in Primary Insomnia. In fact, all but one of the extant studies have been of healthy good sleepers or subjects with Secondary Insomnia. In the present article, we: (1) review the studies that have been undertaken in good sleepers and in patients using functional neuroimaging methodologies, and (2) discuss how these data can inform a research agenda aimed at describing the neuropathophysiology of insomnia.

Long-term, non-nightly administration of zolpidem in the treatment of patients with primary insomnia

INTRODUCTION

While it is common practice that hypnotics are used on a non-nightly basis, few investigations have been undertaken to evaluate the efficacy of the intermittent dosing strategy. The present study was designed to further evaluate this issue within a large scale, double-blind, placebo-controlled, long-term trial.

METHOD

Patients who met DSM-IV criteria for primary insomnia participated in the study from January 2000 through October 2001. Patients were randomly assigned to 1 of 2 treatment groups (zolpidem 10 mg or placebo) for a period of 12 weeks. Ten pills were provided in foil packs on an every-other-week basis, and patients were instructed to take no fewer than 3 and no more than 5 pills per week. Sleep was evaluated daily with sleep diaries. Pill use was recorded in the sleep diaries.

RESULTS

199 patients (mean +/- SD age = 41.0 +/- 12.8 years; 71% female) were randomly assigned to treatment. On mean, patients receiving zolpidem exhibited (vs. baseline) a 42% decrease in sleep latency, a 52% reduction in number of awakenings, a 55% decrease in wake time after sleep onset, and a 27% increase in total sleep time. These positive clinical gains did not diminish with time and were not associated with dose escalation. There was also no evidence of rebound insomnia.

CONCLUSIONS

Over a period of 12 weeks of intermittent treatment with zolpidem, sleep continuity was significantly improved, the clinical gains were sustained, and there was no evidence of subjective rebound insomnia between doses or increases in the amount of medication used during the study interval.

Suicidal ideation in outpatients with chronic musculoskeletal pain: an exploratory study of the role of sleep onset insomnia and pain intensity

OBJECTIVES

Sleep disturbance, depression, and heightened risk of suicide are among the most clinically significant sequelae of chronic pain. While sleep disturbance is associated with suicidality in patients with major depression and is a significant independent predictor of completed suicide in psychiatric patients, it is not known whether sleep disturbance is associated with suicidal behavior in chronic pain. This exploratory study evaluates the importance of insomnia in discriminating suicidal ideation in chronic pain relative to depression severity and other pain-related factors.

METHODS

Fifty-one outpatients with non-cancer chronic pain were recruited. Subjects completed a pain and sleep survey, the Pittsburgh Sleep Quality Index, the Beck Depression Inventory, and the Multidimensional Pain Inventory. Subjects were classified as "suicidal ideators" or "non-ideators" based on their responses to BDI-Item 9 (Suicide). Bivariate analyses and multivariate discriminant function analyses were conducted.

RESULTS

Twenty-four percent reported suicidal ideation (without intent). Suicidal ideators endorsed higher levels of: sleep onset insomnia, pain intensity, medication usage, pain-related interference, affective distress, and depressive symptoms (P < 0.03). These 6 variables were entered into stepwise discriminant function analyses. Two variables predicted group membership: Sleep Onset Insomnia Severity and Pain Intensity, respectively. The discriminant function correctly classified 84.3% of the cases (P < 0.0001).

DISCUSSION

Chronic pain patients who self-reported severe and frequent initial insomnia with concomitant daytime dysfunction and high pain intensity were more likely to report passive suicidal ideation, independent from the effects of depression severity. Future research aimed at determining whether sleep disturbance is a modifiable risk factor for suicidal ideation in chronic pain is warranted.

No association of sleep with total daily physical activity in normal sleepers

The aim of two studies was to examine both between-subjects and within-subjects associations between daily amounts of physical activity and sleep in the home environment. Study 1 examined self-reported exercise durations and sleep diaries for 105 consecutive days in 31 college students who were normal sleepers. Between-subjects associations of mean exercise with mean sleep were assessed with Spearman rank-order correlations. Within-subjects correlations were determined across 105 days, and by comparing sleep on the 11 most active vs. the 11 least active days. Study 2 examined 71 physically active adults (n=38 ages 18-30 years, and n=33 ages 60-75 years), the majority of whom were normal sleepers. Over seven consecutive days, physical activity was assessed via actigraphy and a diary-derived estimate of energy expenditure, and sleep was assessed via actigraphy and sleep diaries. Between-subjects associations of mean physical activity with mean sleep were assessed with partial correlations, controlling for age. Within-subjects associations were assessed with ANCOVAs, with daily physical activity serving as the covariate, and by comparing sleep on the most active vs. the least active day. No significant within-subjects associations between physical activity and sleep were found in the main analyses of either study. Two small, but significant, between-subjects correlations between different physical activity measures and subjective sleep were found in Study 2. These results fail to support epidemiologic data on the value of exercise for sleep, but are consistent with experimental evidence showing only modest effects of exercise on sleep.

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.

On the comparability of pharmacotherapy and behavior therapy for chronic insomnia. Commentary and implications

Recently, we undertook an empirical review using meta-analytic techniques to assess the extent to which these therapeutic strategies produce comparable outcomes. No differences between the two therapeutic strategies were found, except for sleep latency (SL). Behavior therapy demonstrated a greater reduction in latency to sleep onset as compared to pharmacotherapy. In the present paper, we provide a brief summary of our meta-analysis and then (1) critically review the outcomes and (2) place the findings into a larger context that takes into account what factors represent barriers to treatment and how can we insure that in the future patients will have increased access to behavioral sleep medicine services.

Improving compliance with nasal CPAP and vigilance in older adults with OAHS

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.

Neuroimaging of NREM sleep in primary insomnia: a Tc-99-HMPAO single photon emission computed tomography study

STUDY OBJECTIVES

The objectives of this study were to: 1) demonstrate the feasibility of combining polysomnography and SPECT neuroimaging to study NREM sleep in primary insomnia and 2) evaluate possible functional CNS abnormalities associated with insomnia.

DESIGN

Patients with insomnia and good sleeper controls were studied polysomnographically for three nights with a whole brain SPECT Scan of NREM sleep on Night 3. Groups were screened for medical/psychiatric history, substance use, and matched on age, body mass index, and education.

SETTING

Sleep Research Laboratory and Nuclear Medicine Center

PARTICIPANTS

Nine females, 5 patients with chronic psychophysiologic insomnia and 4 healthy good sleepers (mean age 36 years, SD 12, range 27-55).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Tomographs of regional cerebral blood flow during the 1st NREM sleep cycle were successfully obtained. Contrary to our expectations, patients with insomnia showed a consistent pattern of hypoperfusion across all 8 pre-selected regions of interest, with particular deactivation in the basal ganglia (p=.006). The frontal medial, occipital, and parietal cortices also showed significant decreases in blood flow compared to good sleepers (p<.05). Subjects with insomnia had decreased activity in the basal ganglia relative to the frontal lateral cortex, frontal medial cortex, thalamus, occipital and parietal cortices (p<.05).

CONCLUSIONS

This study demonstrated the feasibility of combining neuroimaging and polysomnography to study cerebral activity in chronic insomnia. These preliminary results suggest that primary insomnia may be associated with abnormal central nervous system activity during NREM sleep that is particularly linked to basal ganglia dysfunction.