Overview: a Framework for the Discussion of Sleep in Multiple Sclerosis

The glymphatic system and multiple sclerosis: An evolving connection

Multiple sclerosis (MS) is a complex autoimmune disorder that affects the central nervous system, resulting in demyelination and an array of neurological manifestations. Recently, there has been significant scientific interest in the glymphatic system, which operates as a waste-clearance system for the brain. This article reviews the existing literature, and explores potential links between the glymphatic system and MS, shedding light on its evolving significance in the context of MS pathogenesis. The authors consider the pathophysiological implications of glymphatic dysfunction in MS, the impact of disrupted sleep on glymphatic function, and the bidirectional relationship between MS and sleep disturbances. By offering an understanding of the intricate interplay between the glymphatic system and MS, this review provides valuable insights which may lead to improved diagnostic techniques and more effective therapeutic interventions.

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.

Behavioral Interventions to Improve Sleep Outcomes in Individuals With Multiple Sclerosis: A Systematic Review

BACKGROUND

Sleep disturbances are common in individuals with multiple sclerosis. The objective of this systematic review was to determine effective behavioral interventions to improve their sleep.

METHODS

Literature searches were performed in December 2021 in Ovid MEDLINE, Elsevier Embase, and Web of Science, along with hand searching for grey literature and cited references. Four reviewers independently reviewed titles and abstracts (2 reviewers for each article; n = 830) and the full-text articles (n = 81). Consensus for inclusion was achieved by a fifth reviewer. Thirty-seven articles were eligible for inclusion. Four reviewers extracted relevant data from each study (2 reviewers for each article) using a standard data extraction table. Consensus was achieved for completeness and accuracy of the data extraction table by a fifth reviewer. The same 4 reviewers conducted a quality appraisal of each article to assess the risk of bias and quality of the articles, and consensus was achieved by a fifth reviewer as needed. Descriptive data were used for types of interventions, sleep outcomes, results, and key components across interventions.

RESULTS

Overall, the cognitive behavioral therapy for insomnia, cognitive behavioral therapy/psychotherapy, and education/self-management support interventions reported positive improvements in sleep outcomes. Quality appraisal scores ranged from low to high, indicating potential for bias.

CONCLUSIONS

Variability in the intervention type, intervention dose, outcomes used, training/expertise of interventionist, specific sample, and study quality made it difficult to compare and synthesize results. Further research is necessary to demonstrate the efficacy of most of the interventions.

Rest-Activity Rhythm, Pain, and Motor Activity in Multiple Sclerosis

BACKGROUND

Although the relationships among physical disability, mood disorders, and pain are well described in multiple sclerosis (MS), little is known about whether those symptoms are associated with sleep disturbances.

METHODS

Forty-six patients with MS experiencing pain participated. Sleep was indirectly measured by assessing rest-activity rhythm via actigraphy: interdaily stability, intradaily variability, and relative amplitude. Pain was assessed using visual and verbal analog scales, mood by the Beck Depression Inventory and Symptom Checklist-90, and physical disability by the Expanded Disability Status Scale.

RESULTS

Incorporating mood, pain, and physical disability into 1 regression model resulted in a significant association with interdaily stability.

CONCLUSIONS

Compared with intradaily variability and relative amplitude, interdaily stability seems to be the most vulnerable actigraphy variable for mood disturbances, pain, and physical disabilities.

The reliability and validity of the Turkish version of the apraxia screen of TULIA in multiple sclerosis patients

PURPOSE

The study was aimed to analyze the psychometric properties of the Turkish version of the Apraxia Screen of TULIA (T-AST).

METHODS

A total of 112 patients with multiple sclerosis (MS) were included in the study. T-AST tasks were performed once while recording with a video camera. Two physiotherapists scored T-AST, independently. Rater(1) performed a second assessment of apraxia with AST one week later. The disability was evaluated by Expanded Disability Status Scale (EDSS). Cognitive assessment was carried out with Mini-Mental State Examination (MMSE). Depression was evaluated with Hamilton Depression Rating Scale (HAM-D). Multiple Sclerosis International Quality of Life (MusiQoL) was used to assess the quality of life. In addition, fatigue was evaluated with Fatigue Severity Scale (FSS).

RESULTS

The mean age of the patients was 42.3 ± 11.0 years. The Cronbach's alpha coefficient of the rater(1)'s and rater(2)'s evaluation was 0.820 and 0.800, respectively. ICC score of the intra-rater reliability was 0.960. ICC score of the inter-rater reliability was 0.971. The Spearman correlation coefficients between T-AST and MMSE, EDSS, MusiQoL, HAM-D, FSS were low to excellent, respectively (r = 0.863; p < 0.001, r = -0.768; p < 0.001, r = -0.560; p < 0.001, r = -0.393, p < 0.001, r = -0.324, p < 0.001).

CONCLUSION

The Turkish version of the AST is a reliable and valid tool for assessing upper limb apraxia in patients with MS.Implications for RehabilitationThe Turkish version of the Apraxia Screen of TULIA (T-AST) is a reliable and valid test for assessing apraxia in patients with multiple sclerosis.Considering the short structure, high reliability, and validity, T-AST could be used in clinical practice and clinical trials.

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.

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.

Evaluation of sleep-related respiratory disorders in patients with multiple sclerosis

Patients with multiple sclerosis (MS) often report fatigue, poor sleep and complaint of sleep disorders. Neurofilament light chain (NF-L) has been identified as a potential biomarker for disease progression in MS patients. In this study, we aimed to evaluate sleep characteristics in MS patients and its relationship with the level of serum NF-L. In the present study carried out as a prospective and cross-sectional study, 32 relapsing-remitting MS (RRMS) patients and 32 control subjects were included. Epworth Sleepiness Scale and Fatigue Severity Scale tests were applied to the groups and the full night polysomnography was performed. Serum samples were obtained for NF-L analysis. Apnea-hypopnea index (AHI), AHI in rapid eye movement sleep (AHI REM), percentage of NonREM stage 1 (N1) and NonREM stage 3 (N3) values were significantly different in RRMS patients (p < 0.05). There was correlation between AHI and Expanded Disability Status Scale indicating a negative directed moderate relationship (r = - 0.343 p = 0.055). Serum NF-L correlations with sleep efficiency and percentage of NonREM stage 2 (N2) were showed mild significant correlation (r = - 0.342 as - 0.535, p < 0.05). We found that sleep disorders are prevalent in RRMS patients and it has a negative effect on the clinical outcome of disease. In clinical practice, the association of these two diseases should be taken into consideration because sleep disturbances increase the disability of MS disease especially presenting with fatigue.

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.

Flammer syndrome in multiple sclerosis: diagnostics, prediction, and personalization of treatments

Background

Flammer syndrome (FS) occurs from well-described signs and symptoms. The syndrome itself is not a disease, but it may be a directive marker for advancing therapeutic approaches by predictive and preventive measures as well as for personalization of treatments. The syndrome is related to many diseases, but FS has been rarely studied in multiple sclerosis (MS). The study aimed to determine whether FS signs and symptoms occur more often in people with MS than in healthy controls, and in order to personalize the treatment, we investigated the possible effect of current therapies on FS signs and symptoms.

Methods

Two hundred twenty-two MS patients and 203 healthy controls answered the questionnaire consisting of 15 signs and symptoms of FS.

Results

MS patients had significantly more complaints in 9 items of FS signs and symptoms (cold hands or/and feet, the reduced feeling of thirst, dizziness, drug side effects, other headaches (tension-type, medication overuse), weight loss, feeling cold, long sleep-onset time, and skin blotches) compared to healthy controls. Six items (low blood pressure, tinnitus, increased odor sensitivity, low pain threshold, and perfectionism) were similar between the two groups. The treatment agents currently used did not have any effect on the signs and symptoms of FS.

Conclusion

This study showed that FS might be associated with MS. Injectable or oral agents are not related to the signs and symptoms of FS. Further studies are needed to validate this association.

Relevance of the article for predictive preventive and personalized medicine

FS is common among MS patients. Being aware of this incidence that might impair the life quality of MS patients is useful to predict the comorbidity and develop preventive strategies and applying personalized treatment options and procedures.

Sleep quality can influence the outcome of patients with multiple sclerosis

OBJECTIVE

Sleep plays a role in some oligodendrocyte processes, including myelination. This study aimed to analyze the possible correlations between sleep quality and Multiple Sclerosis (MS) course.

METHODS

Forty patients with Relapsing-Remitting MS were admitted. Based on the score obtained by the Pittsburgh Sleep Quality Index (PSQI), they were divided into good sleepers (<5) and bad sleepers (≥5). A set of data was collected retrospectively for each patient to investigate whether PSQI scores correlated with EDSS score changes, the number and the duration of each relapse and the cumulative day-number of MS reactivations over a three-year period.

RESULTS

In a multivariate model, a PSQI score ≥5 independently and significantly correlated with an increase in number and duration of relapses (p = 0.000) and number of days of MS activity (p = 0.000) during the three-year retrospective observation period.

CONCLUSIONS

The results of this study show that the course of MS may be influenced by sleep quality. Assessment of sleep quality could be used to obtain reliable prognostic information in patients with relapsing-remitting MS. Further investigations are necessary to evaluate whether the correction of sleep disorders may be effective in improving the prognosis of MS patients.