Pathophysiological background and clinical characteristics of sleep disorders in multiple sclerosis

Sleepiness in neurological disorders

Sleepiness is a frequent and underrecognized symptom in neurological disorders, that impacts functional outcomes and quality of life. Multiple and potentially additive factors might contribute to sleepiness in neurological disorders, including sleep quality alterations, circadian rhythm disorders, drugs, and sleep disorders including sleep apnea or central disorders of hypersomnolence. Physician awareness of the possible symptoms of hypersomnolence, and associated causes is of crucial importance to allow proper identification and treatment of underlying causes. This review first provides a brief overview on clinical aspects of excessive daytime sleepiness, and diagnosis tools, then examines its frequency and mechanisms in various neurological disorders, including neurodegenerative disorders, multiple sclerosis, autoimmune encephalitis, epilepsy, and stroke.

The relationship between sleep disorders with patients' demographic-clinical characteristics and quality of life in patients with multiple sclerosis

OBJECTIVES

In this study, the effect of sleep disturbance on the quality of life in MS patients and its relationship between demographic and clinical characteristics of the patients were investigated.

METHODS

67 MS patients and 51 healthy individuals were included in our study. The patient group consisted of 43 women and 24 men. The control group consisted of 32 women and 19 men. Demographic and clinical characteristics of the patients; age, gender, duration of illness, annual number of attacks, treatments, and medical history were recorded and neurological examinations of all patients were performed and disability was determined for each patient with Kurtzke's expanded disability status scale (EDSS). Evaluations were made using demographic data, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Expanded Disability Status Scale (EDSS), Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Berlin Questionnaire and Multiple Sclerosis Quality of Life (MSYK) - 54 Instrument.

RESULTS

We found that the quality of life was significantly impaired in MS patients compared to healthy controls (p < 0.001). And we found that this was related to the presence of progressive MS and chronic fatigue among the clinical features of the patient, sleep-disordered breathing among sleep disorders, poor sleep quality, comorbid anxiety and depression (p = 0.001, p:0.009, p = 0.022, p = 0.007, p < 0.001 and p = 0.001, respectively).

CONCLUSION

All these findings show that sleep disorders in patients with MS are a condition that should be questioned and treated in the follow up of the disease, otherwise it may affect the quality of life of patients negatively.

A pilot, randomized, placebo-controlled study of mindfulness meditation in treating insomnia in multiple sclerosis

OBJECTIVE

Mindfulness is an established approach to reduce distress and stress reactivity by improving awareness and tolerability of thoughts and emotions. This study compares mindfulness training to sleep hygiene in persons with multiple sclerosis (PWMS) who report chronic insomnia, examining sleep efficiency (SE), self-reported sleep quality and quality of life.

METHODS

Fifty-three PWMS were randomized (1:1) in a single-blinded, parallel group design to ten, two-hour weekly sessions of Mindfulness Based Stress Intervention for Insomnia (MBSI-I) over a span of ten weeks or a single, one hour sleep hygiene (SH) session over one day. The primary outcome measure was SE, measured by the Fitbit™ Charge 2 wrist device, at 10 and 16 weeks from the start of study interventions. Self-report outcomes included the Pittsburg Sleep Quality Rating Scale (PSQI), Insomnia Severity Index (ISI) and the Multiple Sclerosis Quality of Life Inventory (MSQLI). Nineteen participants in the MBSI-I group and 24 in the SH group completed the primary study. Subsequently, ten participants in the original SH group participated in the 10-week MSBI-I course and their data was added to the MBSI-I cohort (eMSBI-I).

RESULTS

While neither SE nor the PSQI showed significant differences between MBSI-I, eMBSI-I and SH groups, ISI improved in both the MSBI-I and eMBSI-I vs SH at 10 weeks (p = 0.0014 and p = 0.0275) but not 16 weeks. However, pre and post assessments within the MBSI-I and eMBSI-I cohorts did show significant improvement in the PSQI and ISI at 10 and 16 weeks, while SH was significant in the ISI only at 16 weeks. Several quality of life measurements, including fatigue, mental health and cognitive function favored the mindfulness cohorts.

CONCLUSION

This pilot study demonstrates beneficial effects of MBSR on insomnia, sleep quality and quality of life in PWMS.

TRIAL REGISTRATION

NCT03949296. 14 May 2019.

The effect of distance nurse-led fatigue management on fatigue, sleep quality, and self-efficacy in patients with multiple sclerosis: a quasi-experimental study

BACKGROUND

Fatigue is one of the most common problems in patients with multiple sclerosis (MS) and has adverse effects on their sleep status and self-efficacy. This study aimed to determine the effect of distance nurse-led fatigue management on fatigue, sleep quality, and self-efficacy in patients with MS.

METHODS

This quasi-experimental study was performed on 60 patients with MS in Arak, Iran. Subjects were randomly assigned into intervention and control groups. The intervention group received eight sessions of nurse-led fatigue management training through the Skyroom platform. The control group received only the usual programs. Data were collected before and two months after the intervention using the Fatigue Severity Scale, the Pittsburgh Sleep Quality Index, and the Multiple Sclerosis Self-Efficacy Scale. The significance level in this study was determined 0.05.

RESULTS

After the intervention, the mean score of fatigue severity in the intervention group was significantly lower than the control group (2.52 ± 0.40 vs 5.65 ± 0.52) (P < 0.001). Also, after the intervention, the mean score of self-efficacy in the intervention group was significantly higher than the control group (49.37 ± 3.25 vs 24.43 ± 2.52) (P < 0.001). Furthermore, after the intervention the mean score of sleep quality was lower in intervention group (11.92 ± 2.01) than the control group (15.46 ± 1.40) (P < 0.001).

CONCLUSION

Distance nurse-led fatigue management improved fatigue, sleep quality, and self-efficacy in patients with MS. We recommend the use of these courses as an important step toward improving fatigue, sleep quality, and self-efficacy among these patients.

Research advances in the study of sleep disorders, circadian rhythm disturbances and Alzheimer’s disease

Although there are still no satisfactory answers to the question of why we need to sleep, a better understanding of its function will help to improve societal attitudes toward sleep. Sleep disorders are very common in neurodegenerative diseases and are a key factor in the quality of life of patients and their families. Alzheimer’s disease (AD) is an insidious and irreversible neurodegenerative disease. Along with progressive cognitive impairment, sleep disorders and disturbances in circadian rhythms play a key role in the progression of AD. Sleep and circadian rhythm disturbances are more common in patients with AD than in the general population and can appear early in the course of the disease. Therefore, this review discusses the bidirectional relationships among circadian rhythm disturbances, sleep disorders, and AD. In addition, pharmacological and non-pharmacological treatment options for patients with AD and sleep disorders are outlined.

Sleep disorders in multiple sclerosis: a case-control study using the São Paulo Epidemiologic sleep study (Episono) database

BACKGROUND

Sleep disorders such as obstructive sleep apnea and restless legs syndrome are prevalent in the general population and patients with chronic diseases such as multiple sclerosis (MS).

OBJECTIVES

This study compared the prevalence of sleep disorders complaints, fatigue, depression, and chronotype of adult patients with multiple sclerosis (PwMS) to a representative sample of São Paulo city residents.

METHODS

A comparative study was made between PwMS and volunteers from the São Paulo Epidemiologic Sleep Study (Episono) study. We compared the scores of sleep questionnaires using the multivariate analysis of variance (MANOVA) test to evaluate the effects and analysis of variance (ANOVA) as a follow-up test. Covariates were age, sex, and physical activity. The Pearson correlation test was performed to measure the correlation between Expanded Disability Status Scale (EDSS) and the scores of the sleep questionnaires. Finally, we applied propensity score matching to reduce bias in estimating differences between the two groups. Analyses were performed using Stata 14 (StataCorp, College Station, TX, USA) and IBM SPSS Statistics for Windows version 22.0 (IBM Corp., Armonk, NY, USA).

RESULTS

The Episono group had worse sleep quality, and more excessive daytime sleepiness than PwMS. Obstructive sleep apnea and restless legs syndrome were more frequent in the Episono group. There was no difference in chronotype between the two groups, with morning and intermediate preference. There was no correlation between EDSS and sleep complaints. Fatigue was intensively present among PwMS.

CONCLUSIONS

Disease Modifying Drug (DMD)-treated PwMS had a lower frequency of sleep complaints, no difference in chronotype, and a higher prevalence of fatigue than a sample of São Paulo city residents. The immunomodulatory drugs commonly used to treat MS may have contributed to these findings.

Sleep-Related Breathing Disorders in Multiple Sclerosis: Prevalence, Features and Associated Factors

BACKGROUND

Multiple sclerosis (MS) represents a risk factor for sleep disorders, but there are conflicting results about the prevalence and severity of sleep-related breathing disorders (SRBD) in MS. Most available data come from self-administered questionnaires.

OBJECTIVE

To conduct a polysomnographic study in MS focused on SRBD, compared to a group of healthy controls (HC), also considering the neuroimaging findings. To evaluate the impact of SRBD on vigilance, fatigue and depression in MS.

METHODS

In this cross-sectional, observational, instrumental study, 67 MS patients (men/women: 20/47; mean age: 50.6±8.2 years) underwent PSG and maintenance of wakefulness test. Findings were compared to 67 age-, sex-, BMI-matched HC, by using parametric (Student's t-test) and nonparametric statistics (chi-squared test). A subgroup analysis was then performed, evaluating the influence of brainstem (mesencephalic, pontine and medullary) lesions at neuroimaging on instrumental and clinical data: MS patients with at least one brainstem lesion vs MS patients without vs HC.

RESULTS

The frequency of SRBD was comparable in MS patients and HC. No MS patient had a central apnea index ≥2/h. The respiratory disturbance index (RDI) did not correlate to clinical parameters such as fatigue and depression. Patients with MS were drowsier than HC (47% vs 26%, p = 0.019) and showed a worse sleep pattern, in terms of duration, efficiency and architecture.

CONCLUSION

Our study does not provide evidence of an association between MS-specific symptoms such as fatigue, sleepiness, depression and central or obstructive apneas, even in the presence of brainstem lesions.

Contribution of sleep disturbances to fatigue in multiple sclerosis: a prospective study using clinical and polysomnographic parameters

Background and purpose

Fatigue is amongst the most frequent and disabling symptoms of multiple sclerosis and a close relation between fatigue and sleep quality has been hypothesized. In this study the contribution of sleep disturbances measured by clinical and polysomnographic parameters to fatigue in multiple sclerosis was investigated.

Methods

This was a prospective instrumental study performed at the Neurocenter of Southern Switzerland. Demographic data and clinical characteristics including fatigue (as measured by the modified fatigue impact scale [MFIS]), neurological disability, psychiatric symptoms, medications and sleep‐related variables were collected at baseline visit and by a home full‐night polysomnography. The associations between sleep‐related variables and the MFIS were tested using partial correlations adjusted by demographic and sleep‐unrelated clinical factors.

Results

Seventy‐six patients were included in the study, of whom 53 (69.7%) had an MFIS ≥38 points (median 49.5, interquartile range 31.0–62.0). MFIS scores were positively associated with age, neurological disability, symptoms of depression and anxiety, and use of benzodiazepines and selective serotonin reuptake inhibitors. When adjusting for these variables, the presence of restless legs syndrome (RLS) (r = 0.37, p = 0.005) and periodic leg movements index (r = −0.33, p = 0.014) were associated with MFIS. Excessive daytime sleepiness, total sleep time, sleep efficiency, respiratory disturbances, and percentage of time spent in the different sleep stages (N1, N2, N3 and rapid eye movement) were not associated with fatigue.

Conclusions

Multiple sclerosis patients with a diagnosis of RLS had significantly higher global fatigue scores compared to those without RLS. Future studies should investigate whether medical treatment of RLS can ameliorate fatigue.

Association of Central Hypersomnia and Fatigue in Patients With Multiple Sclerosis: A Polysomnographic Study

OBJECTIVE

To evaluate sleepiness and central hypersomnia in multiple sclerosis (MS)-associated fatigue, we performed long-term polysomnography in patients with MS and healthy controls.

METHODS

Patients with MS and healthy controls completed questionnaires on sleep, fatigue, sleepiness, and depression. They underwent nocturnal polysomnography, multiple sleep latency tests, and bed rest 24-hour polysomnography. Patients were divided into 3 groups (fatigue and sleepiness, fatigue and no sleepiness, neither fatigue nor sleepiness).

RESULTS

Among 44 patients with MS, 19 (43.2%) had fatigue and sleepiness, 15 (34%) had only fatigue, and 10 (22.7%) had neither fatigue nor sleepiness. Compared to 24 controls, patients with fatigue and sleepiness had higher REM sleep percentages (median [interquartile range] 20.5% [19.6-24.7] vs 18.1% [12.6-20.6]), lower arousal indexes (12.7 [7.5-17.0] vs 22.4 [14.3-34.4]), and shorter daytime mean sleep latencies (8.6 [6.3-14.3] vs 16.6 [12.6-19.5] min). Restless leg syndrome, periodic leg movements, and sleep apnea had similar frequencies between groups. Central hypersomnia was found in 10 (53%) patients with fatigue and sleepiness (narcolepsy type 2, n = 2), in 2 (13%) patients with fatigue only, and in 3 (30%) patients with neither fatigue nor sleepiness. Patients with central hypersomnia were younger and sleepier than those without hypersomnia, but had similar levels of fatigue, disability, depression, cognitive performance, and frequencies of the human leukocyte antigen DQB1*0602 genotype. The severity of fatigue increased with higher depression scores, higher sleepiness severity, and lower sleep efficacy.

CONCLUSION

Central hypersomnias are frequent in MS when fatigue and sleepiness are present. Screening them through polysomnography studies is recommended.

Framing multiple sclerosis under a polysomnographic perspective

Multiple sclerosis (MS) is a mainly demyelinating, autoimmune, and disabling neurological disease. In addition to well-known clinically evident symptoms such as coordination or motor problems, increasing attention has been posed to a constellation of less evident symptoms significantly contributing to the clinical impact of MS. Among others, sleep symptoms have been only recently explored. This systematic review summarizes objective sleep findings detected by using polysomnography and their relationship with clinical variables in MS patients. While it is well known that sleep disorders are frequent in MS, objective clinical data are still scarce. Literature based on subjective reports indicate sleep disorders as highly frequent in MS patients; however, objective data are still scarce. New large case-control instrumental investigations are warranted to establish the real objective entity and impact of sleep comorbidities.

Circadian and sleep dysfunction in Alzheimer's disease

Alzheimer's disease (AD) is a devastating and irreversible cognitive impairment and the most common type of dementia. Along with progressive cognitive impairment, dysfunction of the circadian rhythms also plays a pivotal role in the progression of AD. A mutual relationship among circadian rhythms, sleep, and AD has been well-recommended. The etiopathogenesis of the disturbances of the circadian system and AD share some general features that also unlock the outlook of observing them as a mutually dependent pathway. Indeed, the burden of amyloid β (Aβ), neurofibrillary tangles (NFTs), neuroinflammation, oxidative stress, and dysfunction of circadian rhythms may lead to AD. Aging can alter both sleep timings and quality that can be strongly disrupted in AD. Increased production of Aβ and reduced Aβ clearance are caused by a close interplay of Aβ, sleep disturbance and raised wakefulness. Besides Aβ, the impact of tau pathology is possibly noteworthy to the sleep deprivation found in AD. Hence, this review is focused on the primary mechanistic complexities linked to disruption of circadian rhythms, sleep deprivation, and AD. Furthermore, this review also highlights the potential therapeutic strategies to abate AD pathogenesis.

Autonomic symptom burden is an independent contributor to multiple sclerosis related fatigue

OBJECTIVES

To investigate a possible association between autonomic dysfunction and fatigue in people with multiple sclerosis.

METHODS

In 70 people with multiple sclerosis early in the disease course (51 females, mean age 33.8 ± 9.1), quantitative sudomotor axon reflex tests, cardiovascular reflex tests (heart rate and blood pressure responses to the Valsalva maneuver and heart rate response to deep breathing), and the tilt table test were performed. Participants completed the Composite Autonomic Symptom Score 31, the Modified Fatigue Impact Scale, and the Epworth Sleepiness Scale, as well as the Beck Depression Inventory. Cutoff scores of ≥ 38 or ≥ 45 on the Modified Fatigue Impact Scale were used to stratify patients into a fatigued subgroup (N = 17 or N = 9, respectively).

RESULTS

We found clear associations between fatigue and scores in subjective tests of the autonomic nervous system: fatigued patients scored significantly worse on Composite Autonomic Symptom Score 31, and there was a strong correlation between the Modified Fatigue Impact Scale and the Composite Autonomic Symptom Score 31 (r_s = 0.607, p < 0.001). On the other hand, we found only modest associations between fatigue and scores in objective tests of the autonomic nervous system: there was a clear trend for lower sweating outputs at all measured sites, which reached statistical significance for the distal leg and foot. We found weak correlations between the Modified Fatigue Impact Scale and the Valsalva ratio (r_s = - 0.306, p = 0.011), as well as between the Modified Fatigue Impact Scale and quantitative sudomotor axon reflex tests of the forearm, proximal, and distal lower leg (r_s = - 0.379, p = 0.003; r_s = - 0.356, p = 0.005; and r_s = - 0.345, p = 0.006, respectively). A multiple regression model showed that the Composite Autonomic Symptom Score 31, Beck Depression Inventory, and Epworth Sleepiness Scale were independent predictors of fatigue (p = 0.005, p = 0.019, and p = 0.010, respectively).

CONCLUSION

These results suggest that-even early in the course of the disease-people with multiple sclerosis suffer from objective and subjective impairments of the autonomic nervous system. The results also point to an association between autonomic nervous system impairment and multiple sclerosis related fatigue.

Sleep quality, daytime sleepiness, fatigue, and quality of life in patients with multiple sclerosis treated with interferon beta-1b: results from a prospective observational cohort study

Background

Sleep disorders and fatigue are common in multiple sclerosis (MS). The underlying causes are not fully understood, and prospective studies are lacking. Therefore, we conducted a prospective, observational cohort study investigating sleep quality, fatigue, quality of life, and comorbidities in patients with MS.

Methods

Patients with relapsing-remitting MS or clinically isolated syndrome treated with interferon beta-1b were followed over two years. The primary objective was to investigate correlations between sleep quality (PSQI), fatigue (MFIS), and functional health status (SF-36). Secondary objectives were to investigate correlations of sleep quality and daytime sleepiness (ESS), depression (HADS-D), anxiety (HADS-A), pain (HSAL), and restless legs syndrome (RLS). We applied descriptive statistics, correlation and regression analyses.

Results

139 patients were enrolled, 128 were available for full analysis. The proportion of poor sleepers (PSQI≥5) was 55.47% at the beginning and 37.70% by the end of the study (106 and 41 evaluable questionnaires, respectively). Poor sleepers performed worse in MFIS, SF-36, ESS, HADS-D, and HADS-A scores. The prevalence of patients with RLS was low (4.5%) and all were poor sleepers. Poor sleep quality was positively correlated with fatigue and low functional health status. These relationships were corroborated by multivariable-adjusted regression analyses. ESS values and poor sleep quality at baseline seem to predict sleep quality at the one-year follow-up. No variable predicted sleep quality at the two-year follow-up.

Conclusions

Our results confirm the high prevalence of poor sleep quality among patients with MS and its persistent correlation with fatigue and reduced quality of life over time. They highlight the importance of interventions to improve sleep quality.

Trial registration

The study was registered at clinicaltrials.gov: NCT01766063 (registered December 7, 2012). Registered retrospectively (first patient enrolled December 6, 2012).

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1113-5) contains supplementary material, which is available to authorized users.

Results of a randomized, double blind, placebo controlled, crossover trial of melatonin for treatment of Nocturia in adults with multiple sclerosis (MeNiMS)

Background

Nocturia is a common urinary symptom of multiple sclerosis (MS) which can affect quality of life (QoL) adversely. Melatonin is a hormone known to regulate circadian rhythm and reduce smooth muscle activity such as in the bladder. There is limited evidence supporting use of melatonin to alleviate urinary frequency at night in the treatment of nocturia. The aim of this study was to evaluate the effect of melatonin on the mean number of nocturia episodes per night in patients with MS.

Methods

A randomized, double blind, placebo controlled crossover trial was conducted. 34 patients with nocturia secondary to multiple sclerosis underwent a 4-day pre-treatment monitoring phase. The patients were randomized to receive either 2 mg per night (taken at bedtime) of capsulated sustained-release melatonin (Circadin®) or 1 placebo capsule for 6 weeks followed by a crossover to the other regimen for an additional 6 weeks after a 1-month washout period.

Results

From the 26 patients who completed the study, there was no significant difference observed in the signs or symptoms of nocturia when taking 2 mg melatonin compared to placebo. The primary outcome measure, mean number of nocturia episodes on bladder diaries, was 1.8/night at baseline, and 1.4/night on melatonin, compared with 1.6 for placebo (Medians 1.70, 1.50, and 1.30 respectively, p = 0.85). There was also no significant difference seen in LUTS, QoL and sleep quality when taking melatonin. No significant safety concerns arose.

Conclusions

This small study suggests that a low dose of melatonin taken at bedtime may be ineffective therapy for nocturia in MS.

Trial registration

(EudraCT reference) 2012–00418321 registered: 25/01/13. ISRCTN Registry: ISRCTN38687869.

Case Report: Rapid Eye Movement Sleep Behavior Disorder as the First Manifestation of Multiple Sclerosis: A Case Report and Literature Review

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia characterized by brief recurrent episodes of loss of muscle atonia during rapid eye movement sleep, with enacted dreams that cause sleep disruption. Patients with multiple sclerosis (MS) have an increased risk compared with the general population to be affected by a sleep disturbance, including RBD. Patients affected, however, uncommonly can present RBD as the first clinical manifestation of MS without other neurologic deficits. These clinical presentations have usually been attributed to inflammatory lesions in the pedunculopontine nuclei, located in the dorsal pons. We present a case of RBD in a 38-year-old woman who was later diagnosed as having MS due to imaging findings and development of focal neurologic deficits. MS should be considered among the differential diagnoses in patients who present with symptoms of RBD, particularly if they are young and female.

Circadian Rhythm and Alzheimer's Disease

Alzheimer’s disease (AD) is a neurodegenerative disorder with a growing epidemiological importance characterized by significant disease burden. Sleep-related pathological symptomatology often accompanies AD. The etiology and pathogenesis of disrupted circadian rhythm and AD share common factors, which also opens the perspective of viewing them as a mutually dependent process. This article focuses on the bi-directional relationship between these processes, discussing the pathophysiological links and clinical aspects. Common mechanisms linking both processes include neuroinflammation, neurodegeneration, and circadian rhythm desynchronization. Timely recognition of sleep-specific symptoms as components of AD could lead to an earlier and correct diagnosis with an opportunity of offering treatments at an earlier stage. Likewise, proper sleep hygiene and related treatments ought to be one of the priorities in the management of the patient population affected by AD. This narrative review brings a comprehensive approach to clearly demonstrate the underlying complexities linking AD and circadian rhythm disruption. Most clinical data are based on interventions including melatonin, but larger-scale research is still scarce. Following a pathophysiological reasoning backed by evidence gained from AD models, novel anti-inflammatory treatments and those targeting metabolic alterations in AD might prove useful for normalizing a disrupted circadian rhythm. By restoring it, benefits would be conferred for immunological, metabolic, and behavioral function in an affected individual. On the other hand, a balanced circadian rhythm should provide greater resilience to AD pathogenesis.

Sleep Disturbance and Cognitive Dysfunction in Multiple Sclerosis: a Systematic Review

PURPOSE OF REVIEW

The present review summarizes recent research on the association between sleep disturbance and cognitive dysfunction in MS. Assessment methodology, domain-specific associations between sleep disturbance and cognitive dysfunction, and implications for future research and treatment are discussed.

RECENT FINDINGS

All 12 studies included in this review found significant associations between sleep disturbance and cognitive dysfunction; however, results varied considerably depending on the assessment method used and the cognitive domain assessed. Self-reported sleep disturbance generally predicted self-report but not objective measures of cognitive dysfunction. Objective sleep measures (e.g., polysomnography, actigraphy) generally predicted objective impairments in processing speed and attention; however, objective sleep disturbance was more variable in predicting performance in other cognitive domains (e.g., memory, executive function). Sleep disturbance may help predict future cognitive decline in MS. Results highlight the need to integrate sleep assessment into routine MS care. Interventions aimed treating sleep disturbance may offer promise for improving cognitive dysfunction in MS.

Causes, consequences, and cures for neuroinflammation mediated via the locus coeruleus: noradrenergic signaling system

Aside from its roles in as a classical neurotransmitter involved in regulation of behavior, noradrenaline (NA) has other functions in the CNS. This includes restricting the development of neuroinflammatory activation, providing neurotrophic support to neurons, and providing neuroprotection against oxidative stress. In recent years, it has become evident that disruption of physiological NA levels or signaling is a contributing factor to a variety of neurological diseases and conditions including Alzheimer's disease (AD) and Multiple Sclerosis. The basis for dysregulation in these diseases is, in many cases, due to damage occurring to noradrenergic neurons present in the locus coeruleus (LC), the major source of NA in the CNS. LC damage is present in AD, multiple sclerosis, and a large number of other diseases and conditions. Studies using animal models have shown that experimentally induced lesion of LC neurons exacerbates neuropathology while treatments to compensate for NA depletion, or to reduce LC neuronal damage, provide benefit. In this review, we will summarize the anti-inflammatory and neuroprotective actions of NA, summarize examples of how LC damage worsens disease, and discuss several approaches taken to treat or prevent reductions in NA levels and LC neuronal damage. Further understanding of these events will be of value for the development of treatments for AD, multiple sclerosis, and other diseases and conditions having a neuroinflammatory component. The classical neurotransmitter noradrenaline (NA) has critical roles in modulating behaviors including those involved in sleep, anxiety, and depression. However, NA can also elicit anti-inflammatory responses in glial cells, can increase neuronal viability by inducing neurotrophic factor expression, and can reduce neuronal damage due to oxidative stress by scavenging free radicals. NA is primarily produced by tyrosine hydroxylase (TH) expressing neurons in the locus coeruleus (LC), a relatively small brainstem nucleus near the IVth ventricle which sends projections throughout the brain and spinal cord. It has been known for close to 50 years that LC neurons are lost during normal aging, and that loss is exacerbated in neurological diseases including Parkinson's disease and Alzheimer's disease. LC neuronal damage and glial activation has now been documented in a variety of other neurological conditions and diseases, however, the causes of LC damage and cell loss remain largely unknown. A number of approaches have been developed to address the loss of NA and increased inflammation associated with LC damage, and several methods are being explored to directly minimize the extent of LC neuronal cell loss or function. In this review, we will summarize some of the consequences of LC loss, consider several factors that likely contribute to that loss, and discuss various ways that have been used to increase NA or to reduce LC damage. This article is part of the 60th Anniversary special issue.

Sleep Disturbances in Patients with Medical Conditions

Sleep-wake cycle disturbances are prevalent in patients with medical conditions and frequently present as part of a symptom cluster. Sleep disturbances impair functioning and quality of life, decrease adherence to treatments of the primary medical condition, and increase morbidity and mortality. The pathophysiology of sleep disturbances in these patients involves alterations in immune and neuroendocrine function and shares common pathophysiologic pathways with comorbidities such as fatigue and depression. Emphasis is placed on the evaluation and management of medical and psychiatric comorbidities and other factors contributing to sleep problems. Primary treatments include cognitive-behavioral therapy and pharmacotherapy.