Sleep disorders in multiple sclerosis

Evolving relationship between respiratory functions & impairment in sleep and cognition in patients with multiple sclerosis

BACKGROUND

The most apparent source of disability in patients with multiple sclerosis (MS) is the physical and mental impact. The pathophysiological mechanisms of cognitive dysfunction are multifactorial although hypoventilation secondary to respiratory dysfunction may contribute to cognitive decline.

METHODS

This study was conducted on 146 MS patients with baseline clinical assessments including the Epworth sleepiness scale (ESS) and physical disability was assessed using the Expanded Disability Status Scale (EDSS). Cognitive testing was performed utilizing the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and the Perceived Deficits Questionnaire (PDQ). Respiratory functions were assessed by spirometry and the respiratory muscle functional assessment was done by maximal mouth pressure measurement.

RESULTS

The respiratory muscle function test had a significant negative correlation with the score of ESS and PDQ scale and a significant positive correlation with the BICAMS scale score (p < 0.001). The ESS and PDQ scores were significantly negatively correlated with forced expiratory volume in the first second (FEV1)/ forced vital capacity (FVC) (p = 0.03, 0.02), FVC supine (p = 0.03, 0.01), FVC upright- FVC supine (ΔFVC) (p < 0.001, <0.001) FEV1 (p < 0.001) and FVC (L) (p < 0.001), respectively. While the BICAMS showed a significant positive correlation with spirometry results except FVC upright. ESS scores were significantly correlated with the BICAMS and PDQ scale score (p < 0.001).

CONCLUSION

Among MS patients, impaired respiratory functions are significantly associated with sleep disturbance and cognitive impairment. Thus the spirometry and respiratory muscle strength assessment are necessary from the early phase of MS.

Fatigue in multiple sclerosis - a brief review

Fatigue is the most common and debilitating symptom in multiple sclerosis (MS) and is believed to be distinctly different from fatigue seen in other chronic conditions. It can affect a patient's mood, sleep and have a detrimental effect on their quality of life. In the recent years much literature has emerged in an attempt to elucidate the potential causes and treatment of this common symptom. This review article aims to examine the most recent theories on the pathophysiology of fatigue in MS as well as its association with sleep and depression. We describe the pharmacological and non-pharmacological approaches to its treatment and propose a multidisciplinary, patient enabled and individualised manner to the management of fatigue in MS.

Association of multiple sclerosis with restless legs syndrome and other sleep disorders in women

OBJECTIVE

To assess the association of multiple sclerosis (MS) with concurrent restless legs syndrome (RLS) and daytime sleepiness. We also prospectively examined whether women with MS had an increased risk of developing RLS during 4 years of follow-up.

METHODS

The main analysis was based on a cross-sectional study of 65,544 women (aged 41-58 years) free of diabetes, arthritis, and pregnancy, who were participating in the Nurses' Health Study II cohort. Participants were considered to have RLS if they met 4 RLS diagnostic criteria recommended by the International Restless Leg Syndrome Study Group and had restless legs ≥ 5 times/month. MS was self-reported and confirmed by medical record review.

RESULTS

Among women with MS, the prevalence of RLS and severe RLS (15+ times/month) were 15.5% and 9.9% in 2005, respectively, relative to 6.4% and 2.6% among women without MS. After adjustment for potential confounders and the presence of other sleep disorders, women with MS had a higher likelihood of having RLS (odds ratio [OR] = 2.72, 95% confidence interval [CI] 1.89-3.93), severe RLS (OR = 4.12, 95% CI 2.65-6.42), and daily daytime sleepiness (OR = 2.11, 95% CI 1.31-3.42) compared with women without MS. Among the 172 women who had MS and were free of RLS in 2005, 9 developed RLS (5.2%) during a 4-year period and all had severe RLS. The adjusted relative risk of severe RLS was 3.58 (95% CI 1.53-8.35), comparing women with MS at baseline with those without MS.

CONCLUSION

Women with MS had a significantly higher prevalence of RLS and daytime sleepiness and an increased risk of developing RLS in the future.

Sleepiness, fatigue, and risk of obstructive sleep apnea using the STOP-BANG questionnaire in multiple sclerosis: a pilot study

PURPOSE

This study aims: (1) to identify patients with multiple sclerosis (MS) who are at high risk for obstructive sleep apnea (OSA) by utilizing the STOP-BANG questionnaire and (2) to evaluate the relationship between OSA risk as determined by the STOP-BANG questionnaire and self-reported sleepiness and fatigue using the Epworth Sleepiness Scale (ESS) and the Fatigue Severity Scale (FSS), respectively.

METHODS

A total of 120 consecutive patients presenting to the UC Davis Neurology MS Clinic were invited to participate in an anonymous survey. The exclusion criteria were: age <18 years, indefinite MS diagnosis, or incomplete survey.

RESULTS

There were 103 subjects included in our study: 42% of subjects (n = 43) met the criteria for high-risk OSA, 69% of subjects (n = 71) screened high for fatigue (FSS ≥ 4), but only 24 subjects (23%) screened high for excessive daytime sleepiness (ESS > 10). In males, 44% of the variation in ESS scores and 63% in FSS scores were explained by the STOP-BANG components. However, only 17% of the variation in ESS scores and 15% of the variation in FSS scores was explained by the STOP-BANG components in females.

CONCLUSIONS

Over 40% of MS patients were identified as high risk for OSA based on the STOP-BANG questionnaire. The STOP-BANG questionnaire offers clinicians an efficient and objective tool for improving detection of OSA risk in MS patients.

Early life environment and developmental immunotoxicity in inflammatory dysfunction and disease

Components of the innate immune system such as macrophages and dendritic cells are instrumental in determining the fate of immune responses and are, also, among the most sensitive targets of early life environmental alterations including developmental immunotoxicity (DIT). DIT can impede innate immune cell maturation, disrupt tissue microenvironment, alter immune responses to infectious challenges, and disrupt regulatory responses. Dysregulation of inflammation, such as that observed with DIT, has been linked with an increased risk of chronic inflammatory diseases in both children and adults. In this review, we discuss the relationship between early-life risk factors for innate immune modulation and promotion of dysregulated inflammation associated with chronic inflammatory disease. The health risks from DIT-associated inflammation may extend beyond primary immune dysfunction to include an elevated risk of several later-life, inflammatory-mediated diseases that target a wide range of physiological systems and organs. For this reason, determination of innate immune status should be an integral part of drug and chemical safety evaluation.