Sleep disturbances in multiple sclerosis

Sleep and oligodendrocyte functions

Transcriptomic studies have revealed that the brains of sleeping and awake animals differ significantly at the molecular level, with hundreds of brain transcripts changing their expression across behavioral states. However, it was unclear how sleep affects specific cells types, such as oligodendrocytes, which make myelin in the healthy brain and in response to injury. In this review, I summarize the recent findings showing that several genes expressed at higher levels during sleep are involved in the synthesis/maintenance of all membranes and of myelin in particular. In addition, I will discuss the effect of sleep and wake on oligodendrocyte precursor cells (OPCs), providing a working hypothesis on the function of REM sleep and acetylcholine in OPC proliferation.

Neuroglia and their roles in central respiratory control; an overview

While once viewed as mere housekeepers, providing structural and metabolic support for neurons, it is now clear that neuroglia do much more. Phylogenetically, they have undergone enormous proliferation and diversification as central nervous systems grew in their complexity. In addition, they: i) are morphologically and functionally diverse; ii) play numerous, vital roles in maintaining CNS homeostasis; iii) are key players in brain development and responses to injury; and, iv) via gliotransmission, are likely participants in information processing. In this review, we discuss the diverse roles of neuroglia in maintaining homeostasis in the CNS, their evolutionary origins, the different types of neuroglia and their functional significance for respiratory control, and finally consider evidence that they contribute to the processing of chemosensory information in the respiratory network and the homeostatic control of blood gases.

Autonomic dysfunction in multiple sclerosis

Multiple sclerosis (MS) is the leading cause of neurological disability in young adults. Since the pathophysiology of MS is characterized by dissemination in space, as well as in time, the autonomic nervous system is inevitably damaged in the course of the disease in many patients and the proportion of affected patients increases with disease duration. Autonomic dysfunction (AD) in MS is explained by lesions in regions responsible for autonomic regulation such as nuclei in the periventricular region of fourth ventricle in the brainstem as well as medullar lesions. Reports about frequency of AD in MS patients vary notably between groups. Nevertheless its impact on quality of life is substantial but, unfortunately, often overlooked. The aim of this article is to present a concise review of various symptoms and signs of autonomic system dysfunction in MS.

Melatonin acts as antioxidant and improves sleep in MS patients

The relationship between the prevalence of multiple sclerosis (MS) and sunlight's ultraviolet radiation was proved. Oxidative stress plays a role in the pathogenic traits of MS. Melatonin possesses antioxidative properties and regulates circadian rhythms. Sleep disturbances in MS patients are common and contribute to daytime fatigue. The aim of study was to evaluate 5 mg daily melatonin supplementation over 90 days on serum total oxidant status (TOS), total antioxidant capacity (TAC) and its influence on sleep quality and depression level of MS patients. A case-control prospective study was performed on 102 MS patients and 20 controls matched for age and sex. The Kurtzke's Expanded Disability Status Scale, magnetic resonance imaging examinations, Athens Insomnia Scale (AIS), Beck Depression Inventory questionnaires were completed. Serum TOS and TAC levels were measured. We observed higher serum levels of TOS in all MS groups, while after melatonin treatment the TOS levels significantly decreased. The TAC level was significantly lower only in mitoxantrone-treated group and it increased after melatonin supplementation. A strong positive correlation between T1Gd(+) number lesions and TAC level in interferon-beta-1A group was observed. AIS group mean score above 6 defining insomnia were observed in interferon-beta-1B-group, glatiramer acetate-group and mitoxantrone-group: 6.62 ± 2.88, 8.45 ± 2.07, 11.1 ± 3.25, respectively. After melatonin treatment the AIS mean scores decrease in glatiramer acetate-group and mitoxantrone-group achieving 5.25 ± 1.14 and 7.08 ± 2.39, respectively (p < 0.05). Finding from our study suggest that melatonin can act as an antioxidant and improves reduced sleep quality in MS patients.

General health issues in multiple sclerosis: comorbidities, secondary conditions, and health behaviors

PURPOSE OF REVIEW

Comorbid conditions, secondary conditions, and health behaviors are increasingly recognized to be important factors influencing a range of outcomes in multiple sclerosis (MS). This review discusses the most common comorbidities experienced in MS, their impact on clinical outcomes, and the impact of health behaviors. Osteoporosis is a common secondary condition in MS that will be discussed along with vitamin D insufficiency.

RECENT FINDINGS

Mental comorbidity is common in MS; depression has a lifetime prevalence of 50%, while anxiety has a lifetime prevalence of 36%. Physical comorbidity is also common, with the most frequently reported conditions including hyperlipidemia, hypertension, arthritis, irritable bowel syndrome, and chronic lung disease. Fracture risk is increased among patients with MS because of an increased risk of osteoporosis and propensity for falls. Vitamin D insufficiency is common and may contribute to increased fracture risk and increased disease activity. Comorbidities and smoking are associated with diagnostic delays, increased disability progression, lower health-related quality of life, and lower adherence to treatment.

SUMMARY

Physical and mental comorbidity and adverse health behaviors are common in patients with MS. Comorbidities and health behaviors are associated with adverse outcomes in MS and should be considered in the assessment and management of patients with MS.

Future directions of multiple sclerosis rehabilitation research

Multiple sclerosis continues to present a host of rehabilitation challenges, specifically the impact of secondary "hidden" conditions on quality of life, participation, and employment. To discuss the current state of rehabilitation research and direct future research endeavors, a state of the science conference was held in November 2010 in Alexandria, Virginia. The conference was presented by the University of Washington's Multiple Sclerosis Rehabilitation Research and Training Center and focused on the current state of research into secondary conditions, outcomes measurement, employment, and the utility of psychotherapeutic interventions. This article discusses the details and recommendations of this conference.

The sleep-immunity relationship

Research models show a strong interrelationship between sleep quality and immune function. The proinflammatory cytokines, interleukin-1, interleukin-6, and tumor necrosis factor α are classified as official sleep-regulatory substances. However, sleep-promoting properties are also possessed by several other immune and proinflammatory cellular classes. This article reviews the current physiologic evidence for the prominent somnogenic and sleep-regulatory properties inherent to these immune substances. Clinical examples of this relationship are discussed from the perspective of infectious and primarily immune-related conditions associated with significant sleep disruption and from the perspective of immune dysregulation associated with several primary sleep disorders.

Clinical assessment and management of sleep disorders in multiple sclerosis: a literature review

The major sleep disorders are common in multiple sclerosis (MS) and are associated with significant morbidity. Despite this, the rate of recognition and management of these conditions are low. All types of sleep disorders are seen in patients with MS: insomnia, circadian rhythm sleep disorders, sleep-related movement disorders, sleep-related breathing disorders, hypersomnia (narcolepsy), and parasomnia (REM sleep behavior disorder; RBD). This literature review covers the prevalence, clinical features, and treatment of sleep disorders in MS. Based on clinical experience, the spectrum of symptoms associated with MS, and the current knowledge of MS pathophysiology, we have also enclosed proposed strategies for clinical assessment and investigation of sleep disorders in MS patients.

Sleep disturbances in patients with multiple sclerosis

Sleep disturbances constitute one of the important yet underestimated aspects of functioning of patients with multiple sclerosis (MS). The objective of this study was to evaluate sleep disturbances in patients with MS, with regard to demographic factors, disease-related variables, co-existing conditions and fatigue. In 100 MS patients, Epworth Sleepiness Scale (ESS) and a questionnaire about sleep disturbances (SlD) were implemented. ESS and SlD results were analyzed with regard to age, gender, duration of MS, type of its course, degree of disability in Expanded Disability Status Scale (EDSS), MS therapies, coexisting diseases, results of Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). ESS score indicated increased daytime sleepiness in 19 patients. In SlD, 49 subjects reported sleep disturbances and 35 more than one of their kind (most commonly terminal and middle insomnia). No relationships were found between ESS and SlD scores and age, gender, MS duration, type of its course, EDSS or coexisting diseases. In 36 patients, somatic complaints interfered with sleep. The patients with depression had significantly lower ESS result and those currently treated with immunomodulation had significantly lower SlD score. SlD score correlated positively with FSS and MFIS. Sleep disturbances in MS patients may occur independently from demographic and disease-related variables, but they are often influenced by the symptoms of MS and therapies used. Sleep disturbances may contribute to fatigue in the course of MS.