Sleep-related disorders and their relationship with MRI findings in multiple sclerosis

The multidimensional sleep health of individuals with multiple sclerosis and Huntington's disease and healthy controls

STUDY OBJECTIVES

Sleep issues are common for people with neurodegenerative conditions, yet research has focused on specific aspects of sleep. While important, a more holistic approach to investigating sleep, termed "sleep health," considers sleep's positive and negative aspects. Current studies exploring sleep health have lacked a control group for reference. For the first time, this study investigated the sleep health of people living with multiple sclerosis and Huntington's disease (HD) and compared it with a community sample.

METHODS

111 people, including 43 with multiple sclerosis, 19 with HD, and 49 from a community sample, participated in this study. The data, including actigraphy, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale, were collected as part of ongoing research studies. Seven sleep health domains were determined from the collected data, and a composite sleep health score was developed. Analysis of variance and independent t tests were performed to identify population and sex differences.

RESULTS

The HD group had higher sleep regularity and lower sleep rhythmicity than the multiple sclerosis and community sample groups. The HD group had significantly less sleep duration than the multiple sclerosis group. No significant differences between the groups were observed in the sleep health composite score. Males had significantly higher sleep regularity within the HD group but significantly lower sleepiness scores in the community sample.

CONCLUSIONS

These findings indicate that people with HD may experience greater variance in their wake times, therefore decreasing the consistency of being awake or asleep 24 hours apart. Understanding the mechanisms for this should be explored in people with HD.

CITATION

Turner M, Griffiths M, Laws M, Vial S, Bartlett D, Cruickshank T. The multidimensional sleep health of individuals with multiple sclerosis and Huntington's disease and healthy controls. J Clin Sleep Med. 2024;20(6):967-972.

Predictive factors and screening strategy for obstructive sleep apnea in patients with advanced multiple sclerosis

BACKGROUND

Obstructive sleep apnea (OSA) screening questionnaires have been evaluated in Multiple Sclerosis (MS) but not yet validated in patients with advanced disease. The aim of this study is to identify OSA predictive factors in advanced MS and to discuss screening strategies.

METHODS

Oximetry data from 125 patients were retrospectively derived from polysomnographic reports. Univariate and multivariate analysis were used to determine predictive factors for OSA. A two-level screening model was assessed combining the oxygen desaturation index (ODI) and a method of visual analysis.

RESULTS

multivariate analysis showed that among the clinical factors only age and snoring were associated with OSA. Usual predictive factors such as sleepiness, Body mass index (BMI) or sex were not significantly associated with increased Apnea Hypopnea Index (AHI). The ODI was highly predictive (p < 0.0001) and correctly identified 84.1 % of patients with moderate OSA and 93.8 % with severe OSA. The visual analysis model combined with the ODI did not outperform the properties of ODI used alone.

CONCLUSION

As the usual clinical predictors are not associated with OSA in patients with advanced MS, questionnaires developed for the general population are not appropriate in these patients. Nocturnal oximetry seems a pertinent, ambulatory and accessible method for OSA screening in this population.

MS care: integrating advanced therapies and holistic management

Lifestyle and environmental factors are key determinants in disease causality and progression in neurological conditions, including multiple sclerosis (MS). Lack of exercise, poor diet, tobacco smoking, excessive alcohol intake, social determinants of health, concomitant medications, poor sleep and comorbidities can exacerbate MS pathological processes by impacting brain health and depleting neurological reserves, resulting in more rapid disease worsening. In addition to using disease-modifying therapies to alter the disease course, therapeutic strategies in MS should aim to preserve as much neurological reserve as possible by promoting the adoption of a "brain-healthy" and "metabolically-healthy" lifestyle. Here, we recommend self-regulated lifestyle modifications that have the potential to improve brain health, directly impact on disease progression and improve outcomes in people with MS. We emphasise the importance of self-management and adopting a multidisciplinary, collaborative and person-centred approach to care that encompasses the healthcare team, family members and community support groups.

Sleep Disorders and Fatigue among Patients with MS: The Role of Depression, Stress, and Anxiety

Sleep disorders and fatigue represent prominent symptoms frequently experienced by individuals with multiple sclerosis (MS). Some psychological factors such as depression, stress, and anxiety seem to have a relationship with such problems. This study aimed to examine the role of depression, stress, and anxiety in predicting sleep disorders and fatigue among patients with MS. Employing a cross-sectional descriptive-correlational design, the study involved a sample size of 252 participants selected through purposive sampling based on inclusion and exclusion criteria. We utilized a demographic information questionnaire along with the Mini-Sleep Questionnaire (MSQ), Fatigue Severity Scale (FSS), and Depression, Anxiety, and Stress Scale (DASS-21) to collect data and analyzed them applying SPSS22, incorporating statistical measures including Pearson correlation and regression. The results of the Pearson correlation coefficient showed that sleep disorders had a positive and significant relationship with depression (r = 0.56; P < 0.001), stress (r = 0.40; P < 0.001), and anxiety (r = 0.52; P < 0.001). There was no significant relationship between age and the development of sleep disorders in total score (r = -0.001; P < 0.985), but age had a relationship with insomnia (r = -0.146; P < 0.021) and oversleeping (r = 0.153; P < 0.015). Age and fatigue did not have a significant relationship as well (r = -0.044; P < 0.941). In addition, fatigue had a positive and significant relationship with depression (r = 0.52; P < 0.001), stress (r = 0.48; P < 0.001), and anxiety (r = 0.54; P < 0.001). The results of the regression analysis also showed that depression, stress, and anxiety predict 0.37% of the total variance of sleep disorders (F = 48.34; P < 0.001) and 0.35% of the total variance of fatigue (F = 44.64; P < 0.001). Our findings suggest that depression, stress, and anxiety play a significant role in predicting sleep disorders and fatigue among patients with MS. This study has been reported in accordance with the TREND checklist for nonrandomized trials.

Ketogenic diet may improve sleep quality and daytime somnolence in patients affected by multiple sclerosis. Results of an exploratory study

OBJECTIVE/BACKGROUND

Patients with multiple sclerosis (MS) frequently report sleep complaints. The ketogenic diet (KD) is safe and tolerable in MS patients. Our aim was: 1) to investigate the effects of KD on sleep complaints in patients affected by relapsing-remitting MS and 2) to verify if sleep changes can positively impact on psychological status and quality of life (QoL) in these patients.

PATIENTS/METHODS

From January 2020 to November 2022, we consecutively enrolled 21 non-disabled or minimally disabled MS patients. We collected information regarding: 1) anthropometric measures; 2) psychological status by the Depression Anxiety Stress Scale-21; 3) QoL by the Multiple Sclerosis Quality of Life-54 (MSQOL-54); 4) subjective sleep complaints, i.e. sleep quality, by the Pittsburgh Sleep Quality Index (PSQI), and excessive daytime sleepiness (EDS), by the Epworth Sleepiness Scale (ESS).

RESULTS

After 6 months of KD therapy, anthropometric measures considerably changed, psychological status significantly improved, and almost all the MSQOL-54 subscales ameliorated. Regarding sleep, we observed that the global PSQI (T0: 7.7 ± 3.1 versus T1: 4.4 ± 3.1, p = 0.002) and the ESS (T0: 7.5 ± 3.9 versus T1: 4.9 ± 3.2, p = 0.001) scores significantly decreased after KD therapy. At T1, only the global PSQI score was an independent predictor of anxiety, stress, and mental health.

CONCLUSIONS

For the first time, we demonstrated that KD may improve sleep complaints in MS patients. In addition, KD seems to have a positive impact on psychological status and QoL of MS patients, mainly through improving sleep quality. Further controlled studies with larger sample sizes are needed to confirm these preliminary results.

In vivo marker of brainstem myelin is associated to quantitative sleep parameters in healthy young men

The regional integrity of brain subcortical structures has been implicated in sleep-wake regulation, however, their associations with sleep parameters remain largely unexplored. Here, we assessed association between quantitative Magnetic Resonance Imaging (qMRI)-derived marker of the myelin content of the brainstem and the variability in the sleep electrophysiology in a large sample of 18-to-31 years healthy young men (N = 321; ~ 22 years). Separate Generalized Additive Model for Location, Scale and Shape (GAMLSS) revealed that sleep onset latency and slow wave energy were significantly associated with MTsat estimates in the brainstem (pcorrected ≤ 0.03), with overall higher MTsat value associated with values reflecting better sleep quality. The association changed with age, however (MTsat-by-age interaction-pcorrected ≤ 0.03), with higher MTsat value linked to better values in the two sleep metrics in the younger individuals of our sample aged ~ 18 to 20 years. Similar associations were detected across different parts of the brainstem (pcorrected ≤ 0.03), suggesting that the overall maturation and integrity of the brainstem was associated with both sleep metrics. Our results suggest that myelination of the brainstem nuclei essential to regulation of sleep is associated with inter-individual differences in sleep characteristics during early adulthood. They may have implications for sleep disorders or neurological diseases related to myelin.

Sleep disturbances as risk factors for neurodegeneration later in life

The relationship between sleep disorders and neurodegeneration is complex and multi-faceted. Using over one million electronic health records (EHRs) from Wales, UK, and Finland, we mined biobank data to identify the relationships between sleep disorders and the subsequent manifestation of neurodegenerative diseases (NDDs) later in life. We then examined how these sleep disorders' severity impacts neurodegeneration risk. Additionally, we investigated how sleep attributed risk may compensate for the lack of genetic risk factors (i.e. a lower polygenic risk score) in NDD manifestation. We found that sleep disorders such as sleep apnea were associated with the risk of Alzheimer's disease (AD), amyotrophic lateral sclerosis, dementia, Parkinson's disease (PD), and vascular dementia in three national scale biobanks, with hazard ratios (HRs) ranging from 1.31 for PD to 5.11 for dementia. These sleep disorders imparted significant risk up to 15 years before the onset of an NDD. Cumulative number of sleep disorders in the EHRs were associated with a higher risk of neurodegeneration for dementia and vascular dementia. Sleep related risk factors were independent of genetic risk for Alzheimer's and Parkinson's, potentially compensating for low genetic risk in overall disease etiology. There is a significant multiplicative interaction regarding the combined risk of sleep disorders and Parkinson's disease. Poor sleep hygiene and sleep apnea are relatively modifiable risk factors with several treatment options, including CPAP and surgery, that could potentially reduce the risk of neurodegeneration. This is particularly interesting in how sleep related risk factors are significantly and independently enriched in manifesting NDD patients with low levels of genetic risk factors for these diseases.

HIGHLIGHTS

Sleep disorders, particularly sleep apnea, are associated with the risk of Alzheimer's disease, amyotrophic lateral sclerosis, dementia, Parkinson's disease, and vascular dementia in national scale biobanks.These sleep disorders imparted significant risk up to 15 years before the onset of a neurodegenerative disease.The cumulative number of sleep disorders in the electronic health records were associated with a higher risk of neurodegeneration related to dementia and vascular dementia.Sleep related risk factors are independent of genetic risk for Alzheimer's and Parkinson's, potentially compensating for low genetic risk in overall disease etiology.Significant multiplicative interaction exists regarding the combined risk of sleep disorders and Parkinson's disease.

Restless Legs Syndrome and fatigue in multiple sclerosis: A cross-sectional clinical study

BACKGROUND

Restless Legs Syndrome is a sleep-related sensorimotor disorder with a higher prevalence in Multiple Sclerosis (MS) patients than in the general population. Our aim was to determine the prevalence of RLS in a group of relapsing-remittent multiple sclerosis (RRMS) patients, and to investigate whether RLS is associated with MS-related disability, sleep quality, mood disorders and fatigue.

METHODS

In this retrospective, mono-centric, observational study, 92 RRMS patients were recruited (median age 46.5 years, 68.5% female patients). Data on MS clinical and radiological variables were collected. Patients underwent a subjective evaluation with standardized questionnaires on sleep fatigue and mood, which were evaluated by an expert neurologists specialized in sleep disorders about the occurrence of RLS.

RESULTS

Prevalence of RLS in our sample was of 47.8%. Patients with RLS had a significantly higher rate of worse sleep quality and fatigue, compared to non RLS subjects (respectively 56.8% vs. 35.4%, p=0.04 and 54.4% vs 22.7%, p=0.002). Univariate analysis showed that RLS was significantly more frequent in fatigued patients (66.7% vs 38.5% RLS- patients, p=0.009). Multivariate analysis showed that fatigue correlated with MS-related disability (OR 1.556, p=0.011), poor sleep quality (OR 1.192, p 0.036), and mood disorders (OR 1.096, p 0.046). RLS appears to independently increase the risk of fatigue of 50%, without reaching clear statistical significance (OR 1.572, p 0,0079).

CONCLUSION

Our study confirms the high prevalence of RLS in patients with multiple sclerosis and highlights the potential impact of RLS on fatigue and its strict interaction with sleep quality.

Assisted Reproductive Technology and Disease Management in Infertile Women with Multiple Sclerosis

Multiple sclerosis (MS) predominantly affects women of fertile age. Various aspects of MS could impact on fertility, such as sexual dysfunction, endocrine alterations, autoimmune imbalances, and disease-modifying therapies (DMTs). The proportion of women with MS (wMS) requesting infertility management and assisted reproductive technology (ART) is increasing over time. In this review, we report on data regarding ART in wMS and address safety issues. We also discuss the clinical aspects to consider when planning a course of treatment for infertility, and provide updated recommendations to guide neurologists in the management of wMS undergoing ART, with the goal of reducing the risk of disease activation after this procedure. According to most studies, there is an increase in relapse rate and magnetic resonance imaging activity after ART. Therefore, to reduce the risk of relapse, ART should be considered in wMS with stable disease. In wMS, especially those with high disease activity, fertility issues should be discussed early as the choice of DMT, and fertility preservation strategies might be proposed in selected cases to ensure both disease control and a safe pregnancy. For patients with stable disease taking DMTs compatible with pregnancy, treatment should not be interrupted before ART. If the ongoing therapy is contraindicated in pregnancy, then it should be switched to a compatible therapy. Prior to beginning fertility treatments in wMS, it would be reasonable to assess vitamin D serum levels, thyroid function and its antibody serum levels; start folic acid supplementation; and ensure smoking and alcohol cessation, adequate sleep, and food hygiene. Cervico-vaginal swabs for Ureaplasma urealyticum, Mycoplasma hominis, and Chlamydia trachomatis, as well as serology for viral hepatitis, HIV, syphilis, and cytomegalovirus, should be performed. Steroids could be administered under specific indications. Although the available data do not clearly show a definite raised relapse risk associated with a specific ART protocol, it seems reasonably safe to prefer the use of gonadotropin-releasing hormone (GnRH) antagonists for ovarian stimulation. Close clinical and radiological monitoring is reasonably recommended, particularly after hormonal stimulation and in case of pregnancy failure.

Sleep Disturbances in Autoimmune Neurological Diseases

PURPOSE OF REVIEW

To summarize the current evidence on the associations between autoimmune neurological diseases (e.g., multiple sclerosis, myasthenia gravis) and sleep disturbances (e.g., insomnia, parasomnias), as well as to review the main characteristics of sleep disorders with an immune-related pathophysiology (e.g., narcolepsy, anti-IgLON5 disease).

RECENT FINDINGS

An immune-mediated damage of the areas in the central nervous system that control sleep and wake functions (e.g., hypothalamus, brainstem) can lead to sleep disorders and sleep symptoms. Sleep disturbances are the reason to seek for medical attention in certain neuroimmunological conditions (e.g., narcolepsy, anti-IgLON5 disease) where sleep-related alterations are the main clinical feature. The assessment of sleep-related symptomatology and disorders should be included in the routine evaluation of patients with autoimmune neurological diseases. Clinicians should be aware of the typical clinical presentation of certain neuroimmunological disorders mainly affecting sleep.

Case report: Central alveolar hypoventilation in a survivor of cardiopulmonary arrest

Introduction

Ondine's curse is a rare respiratory disorder that is characterized by central alveolar hypoventilation (CAH) during sleep. It is most commonly congenital. However, it can also be acquired very rarely. Herein, we report a young survivor who developed CAH following cardiopulmonary arrest.

Case presentation

A 35-year-old man was admitted to the Intensive Care Unit following unwitnessed cardiopulmonary arrest. Following resuscitative interventions, he remained comatose. Early diagnostic testing showed elevated neuronal specific enolase (28.7 ng/ml), absent cortical responses on evoked potential testing and MRI evidence of restricted diffusion in the cerebellum, hippocampi, juxtacortical white matter, superior cerebellar peduncles, dorsal pons, dorsolateral medulla, and upper cervical spinal cord. Ten days following admission, the patient remained comatose and underwent tracheostomy. He subsequently began to emerge from coma but had persistent unexplained hypotension and bradypnea necessitating ongoing vasopressor and respiratory support. Repeat MRI on hospital day 40 revealed residual FLAIR hyperintensities in the medulla within the nucleus tractus solitarius (NTS). After being discharged to long-term acute care facility, he was successfully liberated from mechanical ventilation 70 days post arrest.

Conclusion

We report the first survivor of cardiopulmonary arrest who was complicated by CAH and hypotension with MRI verified ischemic injury to the bilateral NTS regions. Despite this injury, ventilator and vasopressor dependency resolved over a period of 10 weeks. Our case highlighted the essential functions of NTS in regulating the respiratory and cardiovascular systems.

Sleep Disorders in Patients with Neurologic Disease

OBJECTIVE

This article provides an overview of the growing body of evidence showing bidirectional relationships between sleep and various neurologic disorders.

LATEST DEVELOPMENTS

Mounting evidence demonstrates that disrupted sleep can negatively impact various neurologic disease processes, including stroke, multiple sclerosis, epilepsy, neuromuscular disorders including amyotrophic lateral sclerosis, and headache syndromes. Abnormal sleep can also be a precursor to Alzheimer disease and neurodegenerative disease states such as Parkinson disease and dementia with Lewy bodies. Interventions to improve sleep and treat obstructive sleep apnea may play a vital role in preventing neurologic disease development and progression.

ESSENTIAL POINTS

Sleep disorders are common among patients with neurologic disorders. To provide comprehensive care to patients with neurologic conditions, neurologists must ask patients about sleep issues that may warrant further diagnostic testing, treatment, and sleep medicine referral when indicated.

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.

Understanding neuron-glia crosstalk and biological clocks in insomnia

According to the World Health Organization, about one-third of the population experiences insomnia symptoms, and about 10-15% suffer from chronic insomnia, the most common sleep disorder. Sleeping difficulties associated with insomnia are often linked to chronic sleep deprivation, which has a negative health impact partly due to disruption in the internal synchronisation of biological clocks. These are regulated by clock genes and modulate most biological processes. Most studies addressing circadian rhythm regulation have focused on the role of neurons, yet glial cells also impact circadian rhythms and sleep regulation. Chronic insomnia and sleep loss have been associated with glial cell activation, exacerbated neuroinflammation, oxidative stress, altered neuronal metabolism and synaptic plasticity, accelerated age-related processes and decreased lifespan. It is, therefore, essential to highlight the importance of glia-neuron interplay on sleep/circadian regulation and overall healthy brain function. Hence, in this review, we aim to address the main neurobiological mechanisms involved in neuron-glia crosstalk, with an emphasis on microglia and astrocytes, in both healthy sleep, chronic sleep deprivation and chronic insomnia.

Volumetric changes in hypothalamic subunits in patients with relapsing remitting multiple sclerosis

PURPOSE

Studies on hypothalamic changes in patients with relapsing remitting multiple sclerosis (RRMS) are very scarce, despite the fact that the relationship with the hypothalamus is frequently reported. The aim of the study was to determine the volume of the hypothalamic subunits and the total hypothalamus and its relationship with the total demyelinating lesion volume (TLV) and expanded disability status scale (EDSS) in RRMS patients.

METHODS

In this cross-sectional study, anterior-superior, superior tubular, posterior hypothalamus, anterior-inferior, inferior tubular subunits of hypothalamus, and total hypothalamus volume were calculated, with fully automatic analysis methods using volumetric T1 images of 65 relapsed RRMS patients and 68 healthy controls (HC). Volume changes in the hypothalamus and its subunits in RRMS patients were examined using multivariate analysis of covariance (MANCOVA). The relationship of these volumes with EDSS and TLV was investigated by partial correlation analysis.

RESULTS

There is volume reduction in total hypothalamus (F = 13.87, p < 0.001), anterior-superior (F = 19.2, p < 0.001), superior tubular (F = 10.1, p = 0.002) subunits, and posterior hypothalamus (F = 19.2, p < 0.001) volume in RRMS patients. EDSS correlates negatively with anterior-superior (p = 0.017, r =  - 0.333), superior tubular subunits (p = 0.023, r =  - 0.439), posterior hypothalamus (p < 0.001, r =  - 0.511), and whole hypothalamus volume (p = 0.001, r =  - 0.439). TLV correlates negatively with anterior superior (p < 0.001, r =  - 0.565), anterior inferior (p = 0.002, r =  - 0.431), superior tubular subunits (p = 0.002, r =  - 0.432), posterior hypothalamus (p < 0.001, r =  - 0.703), and whole hypothalamus (p < 0.001, r =  - 0.627) volumes.

CONCLUSION

This study demonstrates a reduction in total hypothalamus volume, anterior-superior, superior tubular, and posterior hypothalamus in patients with RRMS. Anterior-superior and superior tubular subunit, posterior hypothalamus, and total hypothalamus volume were negatively correlated with TLV and EDSS scores.

Disease associations of excessive daytime sleepiness in multiple sclerosis: A prospective study

Background

Excessive daytime sleepiness (EDS) in multiple sclerosis (MS) can be a significant source of disability. Despite this, its prevalence as a patient-reported outcome in this condition has not been well established, and its causes are not well understood.

Methods

We prospectively assessed EDS as part of an observational study for patients referred for diagnostic neuro-ophthalmological testing. EDS was evaluated by the Epworth Sleepiness Scale (ESS), and visual data were also collected as part of a research protocol. Analysis with patient data was performed following the exclusion of patients with known primary sleep disorders.

Results

A total of 69 patients with MS were included in the analysis. The mean ESS was 6.5 with a SD of 4.3. ESS ≥ 10 was present in 23% of the cohort even in the presence of minimal mean neurological disability (Patient Determined Disease Steps (PDDS) = 1.5). The ESS score was not associated with age, sex, disease-related disability, retinal nerve fiber layer (RNFL), or optic neuritis (ON), but displayed an association with visual dysfunction.

Conclusions

There is an increased prevalence of EDS in MS. The increased values of the ESS are not explained by other sleep disorders, suggesting separate mechanisms. Further study of the underlying mechanisms is warranted.

Restless legs syndrome severity associated with reduced physical function in adults with multiple sclerosis

BACKGROUND

Restless legs syndrome (RLS) is a sleep disorder that occurs in approximately 26 % of adults with multiple sclerosis (MS) and may be associated with reduced physical function.

RESEARCH QUESTION

The present study examined the relationship between RLS symptomology (i.e., overall severity, frequency, and occurrence) and physical function outcomes in adults with MS who had RLS.

METHODS

Participants (N = 22) with MS who had RLS came into the laboratory for a single session wherein a rater performed a brief neurological examination for scoring the Expanded Disability Status Scale (EDSS) and completed a demographics questionnaire, the International Restless Legs Syndrome Study Group Scale (IRLS), and the Restless Legs Syndrome Scale-6 (RLS-6) followed by the Short Physical Performance Battery (SPPB) and the Six-minute Walk Test (6 MW).

RESULTS

Bivariate Spearman's rho correlation analyses indicated total IRLS had a strong, negative association with total distance traveled during the 6 MW (ρ = -0.50) and a moderate association with SPPB scores (ρ = -0.43), but not EDSS scores (ρ = 0.28). RLS severity during the day while active had strong, negative associations with total distance traveled during the 6 MW (ρ = -0.61) and SPPB scores (ρ = -0.52), but not EDSS scores (ρ = 0.13).

SIGNIFICANCE

We observed associations between worse overall RLS severity and RLS severity during the day while active with reduced performance during the 6 MW and lower SPPB scores. The management of RLS may offer an opportunity for mitigating reductions in physical function in adults with MS who have RLS.

Neural distinctiveness of fatigue and low sleep quality in multiple sclerosis

BACKGROUND AND PURPOSE

Fatigue and low sleep quality in multiple sclerosis (MS) are closely related symptoms. Here, the associations between the brain's functional connectivity (FC) and fatigue and low sleep quality were investigated to determine the degree of neural distinctiveness of these symptoms.

METHOD

A hundred and four patients with relapsing-remitting MS (age 38.9 ± 10.2 years, 66 females) completed the Modified Fatigue Impact Scale and the Pittsburgh Sleep Quality Index and underwent resting-state functional magnetic resonance imaging. FC was analyzed using independent-component analysis in sensorimotor, default-mode, fronto-parietal and basal-ganglia networks. Multiple linear regression models allowed us to test the association between FC and fatigue and sleep quality whilst controlling for one another as well as for demographic, disease-related and imaging variables.

RESULTS

Higher fatigue correlated with lower sleep quality (r = 0.54, p < 0.0001). Higher fatigue was associated with lower FC of the precentral gyrus in the sensorimotor network, the precuneus in the posterior default-mode network and the superior frontal gyrus in the left fronto-parietal network, independently of sleep quality. Lower sleep quality was associated with lower FC of the left intraparietal sulcus in the left fronto-parietal network, independently of fatigue. Specific associations were found between fatigue and the sensorimotor network's global FC and between low sleep quality and the left fronto-parietal network's global FC.

CONCLUSION

Despite the high correlation between fatigue and low sleep quality in the clinical picture, our findings clearly indicate that, on the neural level, fatigue and low sleep quality in MS are associated with decreased FC in distinct functional brain networks.

The effects of transcranial direct current stimulation on sleep in patients with multiple sclerosis-A pilot study

BACKGROUND

Sleep complaints are commonly reported by patients with multiple sclerosis (PwMS). Several pharmacological and alternative interventions have been tried, but are usually faced by limited efficacy. Hence, exploring other methods such as transcranial direct current stimulation (tDCS), might be of interest. The aim of this study was to assess the effects of bifrontal tDCS on subjective (i.e., Epworth Sleepiness Scale (ESS)) and objective sleep measures (i.e., actigraphy).

METHODS

Seven patients completed the study. Patients randomly received two blocks of five daily sessions each in a crossover design (active and sham, with a washout interval of three weeks). The anode and cathode were placed over the left and right dorsolateral prefrontal cortices, respectively. Sleep assessment included ESS, sleep onset latency, total sleep duration, time in bed, sleep efficiency, waking after sleep onset, and number of awakenings.

RESULTS

Compared to baseline scores (11.14 ± 4.06), significant decrease in ESS was obtained after active intervention (7.86 ± 4.18; p = 0.011), but not after sham intervention (9.57 ± 5.62; p = 0.142). No significant changes were observed with regards to actigraphy measures. Sessions were well tolerated, and no serious side-effects were reported at any time.

CONCLUSION

Bifrontal tDCS resulted in significant improvement in daytime sleepiness, but did not yield any effect on objective sleep measures in PwMS. This discrepency might be explained by the modest association that could exist between objective and subjective sleep measures. In addition, it could be assumed that modulating objective sleep measures would require a larger sample size, more stimulation sessions, or modulation of other cortical areas.

Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

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.

Features of age-related response to sleep deprivation: in vivo experimental studies

Insomnia is currently considered one of the potential triggers of accelerated aging. The frequency of registered sleep-wake cycle complaints increases with age and correlates with the quality of life of elderly people. Nevertheless, whether insomnia is actually an age-associated process or whether it acts as an independent stress-factor that activates pathological processes, remains controversial. In this study, we analyzed the effects of long-term sleep deprivation modeling on the locomotor and orienting-exploratory activity, spatial learning abilities and working memory of C57BL/6 female mice of different ages. We also evaluated the modeled stress influence on morphological changes in brain tissue, the functional activity of the mitochondrial apparatus of nerve cells, and the level of DNA methylation and mRNA expression levels of the transcription factor HIF-1α (Hif1) and age-associated molecular marker PLIN2. Our findings point to the age-related adaptive capacity of female mice to the long-term sleep deprivation influence. For young (1.5 months) mice, the modeled sleep deprivation acts as a stress factor leading to weight loss against the background of increased food intake, the activation of animals' locomotor and exploratory activity, their mnestic functions, and molecular and cellular adaptive processes ensuring animal resistance both to stress and risk of accelerated aging development. Sleep deprivation in adult (7-9 months) mice is accompanied by an increase in body weight against the background of active food intake, increased locomotor and exploratory activity, gross disturbances in mnestic functions, and decreased adaptive capacity of brain cells, that potentially increasing the risk of pathological reactions and neurodegenerative processes.

Distinguishing the Diagnosis and Management of Sleep Disturbance and Sleep Disorders in Multiple Sclerosis

Sleep is a critical issue for quality of life, cognition, and safety among patients with MS. Sleep disturbances from poor sleep hygiene, and multiple sclerosis symptomology, sleep disorders are prevalent; yet evaluation of sleep and screening of sleep disorders are inconsistent. This article presents commonly observed sleep disturbances and disorders, appropriate screening and diagnostic considerations, and management options. Nurses providing care for patients with MS must recognize sleep as an important component in care planning. A comprehensive sleep history and appropriate screening instruments should be incorporated into initial and ongoing assessments, with referral to sleep medicine providers as indicated.

Sleep disturbance and memory dysfunction in early multiple sclerosis

OBJECTIVE

Sleep-dependent memory processing occurs in animals including humans, and disturbed sleep negatively affects memory. Sleep disturbance and memory dysfunction are common in multiple sclerosis (MS), but little is known about the contributions of sleep disturbance to memory in MS. We investigated whether subjective sleep disturbance is linked to worse memory in early MS independently of potential confounders.

METHODS

Persons with early MS (n = 185; ≤5.0 years diagnosed) and demographically matched healthy controls (n = 50) completed four memory tests to derive a memory composite, and four speeded tests to derive a cognitive efficiency composite. Z-scores were calculated relative to healthy controls. Sleep disturbance was defined by the Insomnia Severity Index score ≥ 10. ANCOVAs examined differences in memory and cognitive efficiency between patients with and without sleep disturbance controlling for potential confounds (e.g., mood, fatigue, disability, T2 lesion volume, gray matter volume). Comparisons were made to healthy controls.

RESULTS

Seventy-four (40%) patients reported sleep disturbance. Controlling for all covariates, patients with sleep disturbance had worse memory (z = -0.617; 95% CI: -0.886, -0.348) than patients without disturbance (z = -0.171, -0.425, 0.082, P = .003). Cognitive efficiency did not differ between groups. Relative to healthy controls, memory was worse among patients with sleep disturbance, but not among patients without sleep disturbance.

INTERPRETATION

Sleep disturbance contributes to MS memory dysfunction, which may help explain differential risk for memory dysfunction in persons with MS, especially since sleep disturbance is common in MS. Potential mechanisms linking sleep disturbance and memory are discussed, as well as recommendations for further mechanistic and interventional research.

Sleep in Patients With Neurologic Disease

PURPOSE OF REVIEW

This article provides a discussion of the current evidence and contemporary views on the relationship between sleep disorders and neurologic disease.

RECENT FINDINGS

Disrupted or disordered sleep can be associated with increased morbidity and mortality, the risk of cardiovascular events, increased seizure frequency, and altered immune responses. Studies have implicated disrupted sleep and circadian rhythm dysfunction with both amyloid-β (Aβ) deposition and tau deposition. A bidirectional relationship exists between disrupted sleep and the progression of Alzheimer disease pathology. Insomnia has been reported as a prodromal symptom in autoimmune encephalitis. Primary sleep disorders have now been increasingly recognized as a common comorbid condition in multiple sclerosis, making it imperative that neurologists feel comfortable differentiating multiple sclerosis fatigue from excessive daytime sleepiness caused by primary sleep disorders to optimally treat their patients.

SUMMARY

Sleep disorders are common across the population. By recognizing sleep disorders in patients with neurologic conditions, neurologists can provide comprehensive care and, in some cases, reduce neurologic disease burden.

Unexpected REM sleep excess associated with a pontine lesion in multiple sclerosis

NONE

Sleep disorders are prevalent in patients with multiple sclerosis. In contrast, a frank increase of rapid eye movement (REM) sleep time is a rare phenomenon, mostly described in the context of REM sleep rebound (after sleep deprivation, abrupt withdrawal of antidepressants or neuroleptics, and during the first night of ventilation for severe sleep apnea), but not in link with specific brain lesions. We incidentally found an isolated, marked increase in REM sleep time (200 min, 40% of total sleep time, normative values: 18.2-20.3%) and in rapid eye movements density during REM sleep in a patient with a secondary progressive multiple sclerosis, associated with an anterior pontine demyelinating lesion on magnetic resonance imaging. This result suggests that a network blocking REM sleep in the pons has been damaged.

Sleep Disturbances Associated with Neurological Autoimmunity

Associations between sleep disorders and neurological autoimmunity have been notably expanding recently. Potential immune-mediated etiopathogenesis has been proposed for various sleep disorders including narcolepsy, Kleine-Levin syndrome, and Morvan syndrome. Sleep manifestations are also common in various autoimmune neurological syndromes, but may be underestimated as overriding presenting (and potentially dangerous) neurological symptoms often require more urgent attention. Even so, sleep dysfunction has been described with various neural-specific antibody biomarkers, including IgLON5; leucine-rich, glioma-inactivated protein 1 (LGI1); contactin-associated protein 2 (CASPR2); N-methyl-D-aspartate (NMDA)-receptor; Ma2; dipeptidyl-peptidase-like protein-6 (DPPX); alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA-R); anti-neuronal nuclear antibody type-1 (ANNA-1, i.e., Hu); anti-neuronal nuclear antibody type-2 (ANNA-2, i.e., Ri); gamma-aminobutyric acid (GABA)-B-receptor (GABA-B-R); metabotropic glutamate receptor 5 (mGluR5); and aquaporin-4 (AQP-4). Given potentially distinctive findings, it is possible that sleep testing could potentially provide objective biomarkers (polysomnography, quantitative muscle activity during REM sleep, cerebrospinal fluid hypocretin-1) to support an autoimmune diagnosis, monitor therapeutic response, or disease progression/relapse. However, more comprehensive characterization of sleep manifestations is needed to better understand the underlying sleep disruption with neurological autoimmunity.

Comorbidity in Multiple Sclerosis

Comorbidities in patients with multiple sclerosis (MS) has become an area of increasing interest in the recent years. A comorbidity is defined as any additional disease that coexists in an individual with a given index disease and that is not an obvious complication of the index disease. The aim of this review is to describe the current evidence regarding the range of comorbidities in the population with MS reported in different countries and the current knowledge about the influence of comorbidities on the clinical features and therapeutic challenges in MS. Certain comorbidities are more prevalent in people with MS such as depression, anxiety, cerebro- and cardiovascular diseases, and certain autoimmune disorders such as diabetes, thyroid disease, and inflammatory bowel disease. A previous perception of a trend toward a lower overall risk of cancer in patients with MS appears to be challenged, but there is no evidence on any higher occurrence of malignancies in the population with MS. Comorbidities may modify the clinical presentation of MS, and have implications for treatment choice, adherence, and outcome. Several comorbid conditions are associated with increased disability progression, including diabetes, hypertension, and chronic obstructive pulmonary disease. Comorbidities are common in MS from the time of diagnosis and may account for some of the heterogeneity observed in MS, including diagnostic delay, clinical presentation, degree of disability progression, rate of health care utilization, working ability, employment status, and quality of life. Coexisting diseases and polypharmacy increase the complexity of patient management and poses major challenges, particularly with the increasing number of immunosuppressive disease-modifying therapies.

Restless legs syndrome, sleep quality, and perceived cognitive impairment in adults with multiple sclerosis

BACKGROUND

Restless Legs Syndrome (RLS) is a prominent sleep disorder that often worsens sleep quality and perhaps cognitive function in adults with multiple sclerosis (MS). The present study examined the relationships among RLS prevalence and severity, sleep quality, and perceived cognitive impairment in adults with MS.

METHODS

Participants (N=275) completed the Cambridge-Hopkins Restless Legs Syndrome Questionnaire, the International Restless Legs Syndrome Study Group (IRLS) Scale, the Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ), the Pittsburgh Sleep Quality Index (PSQI), the Patient Determined Disease Steps (PDDS), and a demographic and clinical characteristics questionnaire.

RESULTS

Persons with MS who had RLS (i.e., MS+RLS; n=74) reported significantly worse perceived cognitive impairment compared with those who did not have RLS (n=201; p=0.015). Bivariate correlation analyses within the MS+RLS group indicated that greater RLS severity was significantly associated with more severe perceived cognitive impairment (r=0.274) and sleep quality (r=0.380), and worse perceived cognitive impairment was significantly associated with worse sleep quality (r=0.438). Linear, step-wise regression analyses indicated that RLS severity significantly predicted perceived cognitive impairment (β=0.274), but the inclusion of sleep quality (β=0.391) accounted for the relationship between RLS severity and perceived cognitive impairment (β=0.126).

CONCLUSIONS

Our results suggest that sleep impairment may be an intermediary factor in the association between RLS severity and cognitive impairment in persons with MS who present with RLS. The diagnosis and treatment of RLS symptoms and other effectors of sleep quality could improve neuropsychological consequences of MS.

The Effect of Foot Reflexology on Fatigue, Sleep Quality and Anxiety in Patients with Multiple Sclerosis: A Randomized Controlled Trial

Background: Fatigue, sleep disorders, and anxiety are common symptoms in multiple sclerosis (MS) patients. MS reduced the quality of life by these symptoms in patients. Studies have shown that foot reflexology may reduce some problems of this disease. Objectives: The present randomized controlled trial study investigated the effect of reflexology on fatigue, sleep quality, and anxiety in patients with multiple sclerosis. Methods: This study included 63 patients with MS referred to Arak MS society in 2018 - 2019. Reflexology and placebo intervention had applied twice a week for 4 weeks, and each session lasted about 30 - 40 minutes. Fatigue Impact scale (FIS), Pittsburgh sleep quality index (PSQI) and state-trait anxiety inventory (STAI) was used for data collection before and after the intervention. A significant statistical level was considered 0.05. Data were analyzed using the SPSS software (V. 16.0). Results: Significant improvement was observed in physical fatigue (P = 0.042), sleep quality (P = 0.001) and anxiety (P = 0.034) in the reflexology group after the intervention. Fatigue Impact Scale (FIS) revealed a decrease in fatigue level in MS patients, but these alterations were not significant (P = 0.134). Conclusions: Reflexology is a non-invasive, simple, affordable, and low-cost nursing intervention that can be helpful in reducing physical fatigue, anxiety, and improving sleep quality of people with MS.

Sleep and neurological autoimmune diseases

Neurological autoimmune diseases are characterized by an inappropriate immune response that by mistake targets the nervous system. As a result, patients experiment a number of neurological manifestations that may include insomnia, excessive daytime sleepiness, cataplexy, central hypoventilation, and REM sleep behavior disorder. Polysomnographic evaluation may reveal disorganized sleep architecture involving both NREM and REM sleep, and REM sleep intrusions into wakefulness. The study of sleep disorders in the setting of autoimmune diseases (e.g., narcolepsy, anti-IgLON5 disease, paraneoplastic neurological syndromes) shows that an abnormal immune-mediated (humoral or cellular) response target the neuronal structures (e.g., brainstem, hypothalamus) and neurotransmitters systems (e.g., hypocretin) that regulate sleep resulting in sleep impairment. It is a window to examine the link between the autoimmune system and the sleep regulation at the molecular, cellular, and anatomic level.

Circadian Activity Rhythm in Early Relapsing-Remitting Multiple Sclerosis

While relapsing-remitting is the most prevalent course of multiple sclerosis, the prognostic/predictive markers of the worsening of symptomatology are still debated. With reference to other diseases, the study of the circadian activity rhythm, according to the theoretical framework of the two-process model of sleep regulation and applying functional linear modeling, proved to be useful to identify a possible marker. The usefulness of the study of circadian activity rhythm in multiple sclerosis is strengthened by recent findings indicating a potential involvement of circadian factors in the multifactorial etiopathology of the disorder. The aim of the present study was to verify whether circadian activity rhythm of early relapsing-remitting multiple sclerosis patients presents specific alterations, through functional linear modeling. Thirty-five relapsing-remitting multiple sclerosis patients (24 females; mean age ± SD = 31.51 ± 7.74) and 35 healthy controls (24 females; mean age ± SD = 31.29 ± 8.02) were enrolled. They wore an actigraph around the non-dominant wrist for one week. Relapsing-remitting multiple sclerosis patients showed a peak in motor activity around 5:00 a.m., higher than that of healthy controls. The timing of the peak in motor activity in the patients could be explained according to the hyperactive hypothalamus-pituitary-adrenal axis and higher cortisol awakening response reported in these patients.

The role of sleep and wakefulness in myelin plasticity

Myelin plasticity is gaining increasing recognition as an essential partner to synaptic plasticity, which mediates experience-dependent brain structure and function. However, how neural activity induces adaptive myelination and which mechanisms are involved remain open questions. More than two decades of transcriptomic studies in rodents have revealed that hundreds of brain transcripts change their expression in relation to the sleep-wake cycle. These studies consistently report upregulation of myelin-related genes during sleep, suggesting that sleep represents a window of opportunity during which myelination occurs. In this review, we summarize recent molecular and morphological studies detailing the dependence of myelin dynamics after sleep, wake, and chronic sleep loss, a condition that can affect myelin substantially. We present novel data about the effects of sleep loss on the node of Ranvier length and provide a hypothetical mechanism through which myelin changes in response to sleep loss. Finally, we discuss the current findings in humans, which appear to confirm the important role of sleep in promoting white matter integrity.