Sleep in patients with neurologic and psychiatric disorders

Short-term sleep fragmentation enhances anxiety-related behavior: The role of hormonal alterations

Introduction

The neuroendocrine background of acute sleep fragmentation in obstructive sleep apnea and sleep fragmentation involvement in psychiatric comorbidities, common in these patients, are still largely unknown. The aim of this study was to determine the effects of short-term experimental sleep fragmentation on anxiety -like behavior and hormonal status in rats.

Methods

Male rats were adapted to treadmill (ON and OFF mode with belt speed set on 0.02m/s and 0.00m/s) and randomized to: 1) treadmill control (TC, only OFF mode); 2) motion, activity control (AC, 10min ON and 30min OFF mode) and 3) sleep fragmentation (SF, 30s ON and 90s OFF mode) group. Six hours later, the animals were tested in the open field, elevated plus maze and light/dark test (n = 8/group). Testosterone, estradiol, progesterone and corticosterone were determined in separate animal cohort immediately upon sleep fragmentation (n = 6/group).

Results

SF rats showed decreased rearings number, decreased time spent in the central area and increased thigmotaxic index compared to TC and AC rats in the open field test. Similarly, increased anxiety upon sleep fragmentation was observed in the elevated plus maze and the light/dark test. Significantly lower testosterone, estradiol and progesterone levels were determined in SF in comparison to AC and TC groups, while there was no significant difference in the levels of corticosterone.

Conclusion

Short term sleep fragmentation enhances anxiety-related behavior in rats, which could be partly mediated by the observed hormonal changes presented in the current study in form of testosterone, estradiol and progesterone depletion.

Effects of Kamikihito and Unkei-to on Sleep Behavior of Wild Type and Parkinson Model in Drosophila

Parkinson's disease (PD) is the second most common neurodegenerative disease, and it is associated with sleep behavior disorders. In Drosophila melanogaster disease model, human α-synuclein A30P overexpressing flies (A30P PD model) have been shown for levy body aggregation and movement disorders. We measured sleep rhythms in the A30P PD model flies using the Drosophila Activity Monitoring system and found that they develop sleep defects at 20 days after eclosion. Furthermore, the total amount of sleep is significantly reduced in middle-aged PD model flies and the reduction has been attributed to nighttime sleep. The number and length of sleep bouts also decreased in middle-aged A30P PD model flies. Feeding of the oriental traditional herbal medicines (Kampo), Kamikihito and Unkei-to significantly ameliorate the level of sleep defects in A30P PD model flies. The Kamikihito and Unkei-to recovered 60-min sleep bouts number in the A30P PD model flies to the level of young (5 days after eclosion) flies. Kamikihito recovered sleep both in wild-type and PD model flies. Unkei-to ameliorates not only sleep but also motor function in PD model flies. The data suggest that Kamikihito and Unkei-to might be useful for the sleep defects in human PD patients as well as healthy human.

Sleep Disturbances in Patients With Psychiatric Illnesses

Sleep is essential not only for our physical well-being but also for our mental well-being. Researchers, however, have determined that specific alterations in sleep patterns do exist among patients with psychiatric illnesses. The causes of these abnormalities include both direct and indirect mechanisms. These abnormalities lead to declines in both cognitive function and quality of life. Management should include both nonpharmacological and pharmacological methods. This article will review the types of sleep abnormalities associated with schizophrenia, depression, bipolar disorder, and anxiety disorders and will additionally review treatment options available for each illness.

Sleep state misperception in schizophrenia: Are negative symptoms at work?

OBJECTIVE

This study investigates subjective and objective sleep quality to ascertain whether there is a sleep state misperception in schizophrenia patients, as well as analyze potential effect factors.

METHODS

A total of 148 inpatients with schizophrenia admitted to Beijing HuiLongGuan Hospital were enrolled in this study. The quality of objective sleep was assessed by polysomnography (PSG). On the second day after the successful completion of the PSG evaluation, an interview was arranged to collect patients' recorded subjective evaluation on sleep time, sleep latency, and wake times. Demographic information was collected from an interview, medical records were reviewed, and psychiatric symptoms were assessed using the Positive And Negative Symptom Scale (PANSS).

RESULTS

The main finding of this study was that schizophrenic patients exhibited sleep state misperception with a pattern of overestimation of total sleep time (TST) as well as sleep efficiency (SE), and an underestimation of sleep onset latency (SOL). Regarding the ±standard deviation of the differences between subjective and objective TST as a clinical acceptable range, the patients were divided into three groups: the overestimate group, the normal group, and the underestimate group. The differences of total PANSS score, especially the PANSS-N score in the overestimate group, the normal group and the underestimate group were significant, and there were significant differences between the overestimate group and the other groups.

CONCLUSION

A comprehensive evaluation of the subjective and objective sleep quality in patients with schizophrenia is needed, especially when negative symptoms are severe.

Sleep disruption increases seizure susceptibility: Behavioral and EEG evaluation of an experimental model of sleep apnea

Sleep disruption accompanies sleep apnea as one of its major symptoms. Obstructive sleep apnea is particularly common in patients with refractory epilepsy, but causing factors underlying this are far from being resolved. Therefore, translational studies regarding this issue are important. Our aim was to investigate the effects of sleep disruption on seizure susceptibility of rats using experimental model of lindane-induced refractory seizures. Sleep disruption in male Wistar rats with implanted EEG electrodes was achieved by treadmill method (belt speed set on 0.02 m/s for working and 0.00 m/s for stop mode, respectively). Animals were assigned to experimental conditions lasting 6h: 1) sleep disruption (sleep interrupted, SI; 30s working and 90 s stop mode every 2 min; 180 cycles in total); 2) activity control (AC, 10 min working and 30 min stop mode, 9 cycles in total); 3) treadmill chamber control (TC, only stop mode). Afterwards, the animals were intraperitoneally treated with lindane (L, 4 mg/kg, SI+L, AC+L and TC+L groups) or dimethylsulfoxide (DMSO, SIc, ACc and TCc groups). Convulsive behavior was assessed by seizure incidence, latency time to first seizure, and its severity during 30 min after drug administration. Number and duration of ictal periods were determined in recorded EEGs. Incidence and severity of lindane-induced seizures were significantly increased, latency time significantly decreased in animals undergoing sleep disruption (SI+L group) compared with the animals from TC+L. Seizure latency was also significantly decreased in SI+L compared to AC+L groups. Number of ictal periods were increased and duration of it presented tendency to increase in SI+L comparing to AC+L. No convulsive signs were observed in TCc, ACc and SIc groups, as well as no ictal periods in EEG. These results indicate sleep disruption facilitates induction of epileptic activity in rodent model of lindane-epilepsy enabling translational research of this phenomenon.

Sleep-disordered breathing and psychiatric disorders

Sleep-disordered breathing, the commonest form of which is obstructive sleep apnoea (OSA) is increasingly recognised as a treatable cause of morbidity. It shares many risk factors with psychiatric disorders including behaviours such as smoking and physical comorbidity. Many symptoms of the two overlap, leaving OSA often undetected and undertreated. In the few studies that assess the two, OSA is commonly comorbid with depression (17-45%) and schizophrenia (up to 55%) and possibly bipolar. There is some limited evidence that treating OSA can ameliorate psychiatric symptoms. Some psychotropics, such as narcotics, cause sleep-disordered breathing (SDB), whilst weight-inducing neuroleptics may exacerbate it. An extreme form of SDB, sudden infant death syndrome (SIDS), is a risk in mothers with substance abuse. Being aware of these common comorbidities may help improve psychiatric patient's treatment and quality of life.

Sleep onset/maintenance difficulties and cognitive function in nondemented older adults: the role of cognitive reserve

This study examined the relationship between cognitive function and sleep onset/maintenance difficulties (SO/MD) in nondemented older adults. We hypothesized that SO/MD negatively impacts cognition and that older adults with lower education would be especially vulnerable to its effects. The sample comprised 549 older adults from the Einstein Aging Study (EAS), a community-based cohort. Participants completed neuropsychological assessment and a sleep questionnaire. Univariate ANCOVAs were performed with cognitive performance as a dependent variable, SO/MD (present or absent) and education (lower: ≤ 12 years; higher: >12 years) as between-subjects factors, and age, ethnicity, gender, depression, and cardiovascular comorbidies as covariates. Participants were an average age of 79.7 ± 5.0 years (range = 71-97 years). Fifty-seven percent (n = 314) of the sample met criteria for SO/MD. Among participants with SO/MD, those with lower education performed more poorly on a test of category fluency than participants with higher education (means: 35.2 vs. 41.0; p < .001); among older adults without SO/MD, educational attainment had no measurable effect on cognition (SO/MD × education interaction (F(1,536) = 14.5; p = .00)). Consistent with the cognitive reserve hypothesis, older adults with lower education appear selectively vulnerable to the negative effects of sleep onset/maintenance difficulties on tests of verbal fluency.

Sleep disturbances and fatigue in critically ill patients

Sleep disturbances and fatigue are significant problems for critically ill patients. Existing sleep disorders, underlying medical/surgical conditions, environmental factors, stress, medications, and other treatments all contribute to a patient's inability to sleep. Sleep disturbance and debilitating fatigue that originate during acute illness may continue months after discharge from intensive care units (ICUs). If these issues are unrecognized, lack of treatment may contribute to chronic sleep problems, impaired quality of life, and incomplete rehabilitation. A multidisciplinary approach that incorporates assessment of sleep disturbances and fatigue, environmental controls, appropriate pharmacologic management, and educational and behavioral interventions is necessary to reduce the impact of sleep disturbances and fatigue in ICU patients. Nurses are well positioned to identify issues in their own units that prevent effective patient sleep. This article will discuss the literature related to the occurrence, etiology, and risk factors of sleep disturbance and fatigue and describe assessment and management options in critically ill adults.

Algorithms for the assessment and management of insomnia in primary care

Insomnia is a leading cause of sleep disturbance in primary care practice affecting >30% of people in the United States and can result in psychological and physiological consequences. We aim for a focused discussion of some of the underpinnings of insomnia and practical tips for management (eg, algorithms). A PubMed search was conducted using English language papers between 1997-2007, with the terms "sleep," "insomnia"; "primary care" and "clinics"; "comorbid conditions"; "treatment" and "management." Sleep, psychiatric and medical disorders significantly affect sleep, causing patient suffering, potentially worsening of other disorders and increasing the use of primary care services. We provide an outline for practical assessment and treatment of insomnia in primary care, including the strengths and weaknesses of medications.

Sleep in hospitalized medical patients, part 1: factors affecting sleep

BACKGROUND

Multiple factors lead to sleep disturbances in hospitalized medical patients. Inadequate sleep can lead to both psychological and physiological consequences.

METHODS

A PubMed search was conducted using the terms: ("sleep deprivation," "sleep," or "insomnia") and ("hospitalized," "inpatient," "critical illness," or "acute illness") to review the published data on the topic of sleep in hospitalized medical patients. The search was limited to English-language articles published between 1997 and 2008. Subsequent PubMed searches were performed to clarify the data described in the initial search, including the terms "hospital noise," "hospital environment," "obstructive sleep apnea," and "heart failure."

RESULTS

Few articles specifically addressed the topic of sleep in hospitalized medical patients. Data were limited to observational studies that included outcomes such as sleep complaints and staff logs of wakefulness and sleep. In Part 1, we review normal sleep architecture, and discuss how major medical disorders, the hospital environment, and medications can disrupt sleep during hospitalization. In Part 2, we will propose an evaluation and treatment algorithm to optimize sleep in hospitalized medical patients.

CONCLUSIONS

Hospitalization may severely disrupt sleep, which can worsen pain, cardiorespiratory status, and the psychiatric health of acutely ill patients. Like vital signs, the patient sleep quality reveals much about patients' overall well-being, and should be a routine part of medical evaluation.

Sleep disturbances in an arctic population: the Tromsø Study

Background

Prevalence estimates for insomnia range from 10 to 50% in the adult general population. Sleep disturbances cause great impairment in quality of life, which might even rival or exceed the impairment in other chronic medical disorders. The economic implications and use of health-care services related to chronic insomnia represent a clinical concern as well as a pronounced public health problem. Hypnotics are frequently prescribed for insomnia, but alcohol and over-the-counter sleep aids seem to be more widely used by insomniacs than prescription medications. Despite the complex relationship between insomnia and physical and mental health factors, the condition appears to be underrecognized and undertreated by health care providers, probably due to the generally limited knowledge of the causes and natural development of insomnia.

Methods/Design

The Tromsø Study is an ongoing population-based cohort study with five previous health studies undertaken between 1974 and 2001. This protocol outlines a planned study within the sixth Tromsø Study (Tromsø VI), aiming at; 1) describing sleep patterns in a community-based sample representative of the general population of northern Norway, and 2) examining outcome variables of sleep disturbances against possible explanatory and confounding variables, both within a cross-sectional approach, as well as retrospectively in a longitudinal study – exploring sleep patterns in subjects who have attended two or more of the previous Tromsø studies between 1974 and 2009. First, we plan to perform a simple screening in order to identify those participants with probable sleep disturbances, and secondly to investigate these sleep disturbances further, using an extensive sleep-questionnaire. We will also collect biological explanatory variables, i.e. blood samples, weight, height and blood pressure. We plan to merge data on an individual level from the Tromsø VI Study with data from the Norwegian Prescription Database (NorPD), which is a national registry including data for all prescription drugs issued at Norwegian pharmacies. Participants with sleep disturbances will be compared with pair-matched controls without sleep disturbances.

Discussion

Despite ongoing research, many challenges remain in the characterization of sleep disturbances and its correlates. Future mapping of the biological dimensions, natural history, as well as the behavioral and drug-related aspects of sleep disturbances in a representative population samples is clearly needed.

Chronic insomnia and cognitive functioning among older adults

Chronic insomnia and cognitive impairment are both common complaints among older adults. This study explores the association between chronic insomnia and changes in cognitive functioning among older adults. The study population comprised two groups: 64 older adults without insomnia and 35 older adult insomniacs. The cognitive capacity of each participant was tested at the participant's home using the computerized "MindFit" test (CogniFit, Inc.). In five categories of cognitive functioning, older adult insomniacs displayed impaired performance compared to older adult good sleepers. Specifically, significant differences were found between insomniacs and good sleepers on memory span, allocating attention to a target, time estimation, executive functioning, and integration of two dimensions (visual and semantic) tests. The findings imply that insomnia may have detrimental effects on some cognitive functions in healthy older adults.

Long-term changes in sleep and electroencephalographic activity by chronic vagus nerve stimulation in cats

We previously reported the effect of vagus nerve electrical stimulation (VNS) on sleep and behavior in cats. The aim of the present study is to analyze the long-term effects of VNS on the electroencephalographic (EEG) power spectrum and on the different stages of the sleep-wakefulness cycle in the freely moving cat. To achieve this, six male cats were implanted with electrodes on the left vagal nerve and submitted to 15 rounds of 23 h continuous sleep recordings in three categories: baseline (BL), VNS and post-stimulus recording (PSR). The following parameters were analyzed: EEG power spectrum, total time and number of sleep phases, ponto-geniculo-occipital (PGO) wave density of the rapid eye movement (REM) sleep, and the number of times the narcoleptic reflex was present (sudden transition from wakefulness to REM sleep). Significant changes were detected, such as an enhancement of slow-wave sleep (SWS) stage II; a power increase in the bands corresponding to sleep spindles (8-14 Hz) and delta waves (1-4 Hz) with VNS and PSR; an increase in the total time, number of stages, and density of PGO wave in REM sleep with VNS; a decrease of wakefulness in PSR, and the eventual appearance of the narcoleptic reflex with VNS. The results show that the effect of the VNS changes during different stages of the sleep-wakefulness cycle. In REM sleep, the effect was present only during VNS, while the SWS II was affected beyond VNS periods. This suggests that ponto-medullar and thalamic mechanisms of slow EEG activity may be due to plastic changes elicited by vagal stimulation.

Sleep fragmentation elevates behavioral, electrographic and neurochemical measures of sleepiness

Sleep fragmentation, a feature of sleep apnea as well as other sleep and medical/psychiatric disorders, is thought to lead to excessive daytime sleepiness. A rodent model of sleep fragmentation was developed (termed sleep interruption, SI), where rats were awakened every 2 min by the movement of an automated treadmill for either 6 or 24 h of exposure. The sleep pattern of rats exposed to 24 h of SI resembled sleep of the apneic patient in the following ways: sleep was fragmented (up to 30 awakening/h), total rapid eye movement (REM) sleep time was greatly reduced, non-rapid eye movement (NREM) sleep episode duration was reduced (from 2 min, 5 s baseline to 58 s during SI), whereas the total amount of NREM sleep time per 24 h approached basal levels. Both 6 and 24 h of SI made rats more sleepy, as indicated by a reduced latency to fall asleep upon SI termination. Electrographic measures in the recovery sleep period following either 6 or 24 h of SI also indicated an elevation of homeostatic sleep drive; specifically, the average NREM episode duration increased (e.g. for 24 h SI, from 2 min, 5 s baseline to 3 min, 19 s following SI), as did the NREM delta power during recovery sleep. Basal forebrain (BF) levels of extracellular adenosine (AD) were also measured with microdialysis sample collection and high performance liquid chromatography detection, as previous work suggests that increasing concentrations of BF AD are related to sleepiness. BF AD levels were significantly elevated during SI, peaking at 220% of baseline during 30 h of SI exposure. These combined findings imply an elevation of the homeostatic sleep drive following either 6 or 24 h of SI, and BF AD levels appear to correlate more with sleepiness than with the cumulative amount of prior wakefulness, since total NREM sleep time declined only slightly. SI may be partially responsible for the symptom of daytime sleepiness observed in a number of clinical disorders, and this may be mediated by mechanisms involving BF AD.

Prodromal non-motor symptoms of Parkinson's disease

The motor symptoms of Parkinson's disease (PD), bradykinesia, muscular rigidity, and tremor depend upon degeneration of the dopaminergic neurons in the substantia nigra pars compacta. Recent neuropathological studies show that the Lewy bodies, the intraneuronal landmark of PD, accumulate in several neuronal cell types in the brain. An ascending gradient of pathological involvement, from the medulla oblongata to neocortical areas has been reported. Thus the original view of PD as a disease characterized by selective damage of the dopaminergic neurons in the mesencephalon should be updated into the concept of a severe multisystemic neurodegenerative disorder. Additionally, the neuropathological alterations outside the substantia nigra are soundly correlated with the non-motor symptoms of PD. As a result of these findings, interest is growing in the identification of prodromal non-motor symptoms of PD. Indeed, data from the literature suggest that autonomic disturbances, olfactory dysfunctions, depression and sleep disorders (in particular REM-sleep behavior disorder) may represent prodromal non-motor symptoms of PD. Several tests are available to detect most of these symptoms. Thus, the identification of prodromal non-motor symptoms may contribute to the precocious diagnosis of PD, and might be useful in the future to test the efficacy of neuroprotective agents.

α2 Adrenoceptors are involved in the regulation of the gripping-induced immobility episodes intaiep rats

In 1989 Holmgren et al. (Holmgren et al. 1989 Lab Anim Sci 39:226-228) described a new mutant rat that developed a progressive motor disturbance during its lifespan. The syndrome is characterized by a tremor in the hind limbs followed by ataxia, episodes of tonic immobility, epilepsy, and paralysis. The acronym of these symptoms (taiep) became the name of this autosomic, recessive mutant rat. The taiep rats are neurological mutant animals with a hypomyelination, followed by a progressive demyelination process. At 7-8 months of age, taiep rats develop immobility episodes (IEs) characterized by a cortical desynchronization, associated with the theta rhythm in the hippocampus and changes of the nucal electromyogram (EMG), whose pattern is like rapid-eye-movement (REM) sleep. These rats also show an altered sleep pattern with an equal REM sleep distribution. This study analyzed therole of alpha(2) adrenoceptors in the expression of gripping-induced IEs in 8-month-old male taiep rats. The alpha(2) adrenoceptor agonists clonidine and xylacine increased the frequency of gripping-induced IEs whereas the alpha(2) antagonists yohimbine and idazoxandecreased or prevented such episodes. These findings correlate with the pharmacological observations in narcoleptic dogs and humans in which alpha(2) adrenergic mechanisms are involved in the modulation of cataplexy. Unexpectedly, the repetitive administration of clonidine resulted in jumping behavior, indicative of phasic activation of extensor musculature. Taken together, our results show that alpha(2) adrenoceptors are involved in the modulation in gripping-induced IEs and after the administration of several doses of clonidine produced phasic motor activation.