Sleep in Neuromuscular Diseases

Exploring sleep quality, depressive symptoms, and quality of life in adults with spinal muscular atrophy

Spinal Muscular Atrophy (SMA) is a genetic neuromuscular disorder caused by the mutation of the survival motor neuron 1 (SMN1) gene. Sleep disturbances and their impact on mental health and quality of life in patients with SMA are being understudied, and most of the evidence comes from pediatric SMA patients. We conducted a cross-sectional survey of adult patients with SMA. The participants underwent questionnaires exploring sleep quality with the Pittsburgh Sleep Quality Index (PSQI), depressive symptoms with the Patient Health Questionnaire-9 (PHQ-9), and quality of life with the Short-Form Health Survey 36 (SF-36). Fifty patients with SMA were enrolled in the study: 66 % were females with a median age of 41 years. Of them, 60 % had poor sleep quality, and 72 % had depressive symptoms. SMA 2 patients showed higher PSQI and PHQ-9 scores than SMA 3 patients (8 ± 3 vs 6 ± 1, p < 0.001 and 13±5 vs 7 ± 5, p < 0.001). PSQI total score correlated with the PHQ-9 (r = 0.32, p = 0.02), which was higher in patients with respiratory symptoms. Poor sleep is associated with depressive symptoms and respiratory dysfunction in adult SMA patients. Clinicians should consider sleep quality in SMA patients for optimal care; future studies are needed to understand this aspect better.

Sleep in Myasthenia Gravis: A Questionnaire-Based Study

BACKGROUND

Disturbed sleep and its impact on quality of life (QoL) are underrecognized in myasthenia gravis (MG).

AIMS

To evaluate the quality of sleep in MG using standard sleep questionnaires and assess factors that determine sleep.

SETTINGS AND DESIGN

Prospective, cross-sectional, hospital-based study.

PATIENTS AND METHODS

Fifty patients on stable drug therapy for at least 1 month and age- and gender-matched controls were assessed using standard sleep questionnaires [Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and NIMHANS Comprehensive Sleep Disorders Questionnaire (NCSDQ)].

RESULTS

Myasthenia Gravis Foundation of America (MGFA) grade was I, IIA, IIB, IIIA, IIIB, and IVA in 11, 19, 3, 10, 6, and 1 respectively. The mean PSQI and ESS scores were similar in patients and controls. Patients with abnormal ESS (>10) were older and had greater neck circumference (P = 0.018 and <0.001). Body mass index was greater in patients with PSQI > 5 (P < 0.05). Age, gender, and clinical severity did not affect PSQI. Compared with ESS and PSQI, NCSDQ showed higher frequency of disturbed sleep, snoring, early morning headache, difficulty in initiation, and maintenance of sleep in MG, although the differences between patients and controls were not significant. No correlation was found between QoL and ESS or PSQI.

CONCLUSION

Patients of MG with stable clinical course with adequate treatment have sleep quality comparable with healthy controls. Longitudinal assessment of sleep quality at multiple time points throughout the disease course and correlating with cross-sectional disease severity may further delineate the impact of disease on sleep and QoL.

Polysomnographic findings of myotonic dystrophy type 1/type 2: evidence from case-control studies

STUDY OBJECTIVES

This study explores polysomnographic and multiple sleep latency test (MSLT) differences between myotonic dystrophy type 1/type 2 (DM1/DM2) patients and controls.

METHODS

An electronic literature search was conducted in MEDLINE, EMBASE, All EBM databases, and Web of Science from inception to Aug 2023.

RESULTS

Meta-analyses revealed significant reductions in sleep efficiency, N2 percentage, mean SpO2, and MSLT measured mean sleep latency, and increases in N3 sleep, wake time after sleep onset, apnea hypopnea index, and periodic limb movement index in DM1 patients compared with controls. However, any differences of polysomnographic sleep change between DM2 patients and controls could not be established due to limited available studies.

CONCLUSIONS

Multiple significant polysomnographic abnormalities are present in DM1. More case-control studies evaluating polysomnographic changes in DM2 compared with controls are needed.

Subjective Sleep Quality as it Relates to Cognitive and Physical Function in Spinal Muscular Atrophy Patients

Sleep quality and its association with cognition has been widely studied in some neurodegenerative diseases, but less is known about this association in spinal muscular atrophy (SMA). In adult SMA (n = 21) patients and age-matched controls (n = 23), we assessed subjectively measured sleep quality and daytime somnolence. Cognition was assessed with a multi-domain neuropsychological battery. Further, we investigated the association between clinical functional scores and sleep questionnaire scores. Among SMA patients, better motor and limb function was associated with better subjective sleep quality (p's<  0.05). Clinicians should consider sleep quality in patient care and future studies are needed to better understand these relationships.

Methods and Applications in Respiratory Physiology: Respiratory Mechanics, Drive and Muscle Function in Neuromuscular and Chest Wall Disorders

Individuals with neuromuscular and chest wall disorders experience respiratory muscle weakness, reduced lung volume and increases in respiratory elastance and resistance which lead to increase in work of breathing, impaired gas exchange and respiratory pump failure. Recently developed methods to assess respiratory muscle weakness, mechanics and movement supplement traditionally employed spirometry and methods to evaluate gas exchange. These include recording postural change in vital capacity, respiratory pressures (mouth and sniff), electromyography and ultrasound evaluation of diaphragmatic thickness and excursions. In this review, we highlight key aspects of the pathophysiology of these conditions as they impact the patient and describe measures to evaluate respiratory dysfunction. We discuss potential areas of physiologic investigation in the evaluation of respiratory aspects of these disorders.

Optimal NIV Medicare Access Promotion: Patients With Thoracic Restrictive Disorders: A Technical Expert Panel Report From the American College of Chest Physicians, the American Association for Respiratory Care, the American Academy of Sleep Medicine, and the American Thoracic Society

The existing coverage criteria for noninvasive ventilation (NIV) do not recognize the benefits of early initiation of NIV for those with thoracic restrictive disorders and do not address the unique needs for daytime support as the patients progress to ventilator dependence. This document summarizes the work of the thoracic restrictive disorder Technical Expert Panel working group. The most pressing current coverage barriers identified were: (1) delays in implementing NIV treatment; (2) lack of coverage for many nonprogressive neuromuscular diseases; and (3) lack of clear policy indications for home mechanical ventilation (HMV) support in thoracic restrictive disorders. To best address these issues, we make the following key recommendations: (1) given the need to encourage early initiation of NIV with bilevel positive airway pressure devices, we recommend that symptoms be considered as a reason to initiate therapy even at mildly reduced FVCs; (2) broaden CO2 measurements to include surrogates such as transcutaneous, end-tidal, or venous blood gas; (3) expand the diagnostic category to include phrenic nerve injuries and disorders of central drive; (4) allow a bilevel positive airway pressure device to be advanced to an HMV when the vital capacity is < 30% or to address severe daytime respiratory symptoms; and (5) provide additional HMV when the patient is ventilator dependent with use > 18 h per day. Adoption of these proposed recommendations would result in the right device, at the right time, for the right type of patients with thoracic restrictive disorders.

Myasthenia Symptom Burden, Fatigue, and Sleep: Are They Related?

OBJECTIVE

Our aim is to explore the relationship between myasthenia gravis (MG)-related symptom burden, sleep quality, and fatigue in a diverse group of self-identified MG patients.

METHODS

Patients provided relevant myasthenia disease data and completed the MG QOL-15, Epworth sleepiness scale, Pittsburgh Sleep Quality Index, and fatigue severity score (FSS) online. MG activities of daily living scale (MG-ADL) was completed on a follow-up telephone interview.

RESULTS

One hundred ninety-six patients completed the online survey and 99 provided MG-ADL data. The mean age was 52 ± 15.34 years, 88 were acetylcholine receptor antibody positive, and 21 were muscle specific kinase positive. The mean MG-ADL was 6.81, indicating a moderate MG disease burden. Forty-seven (24%) reported high Epworth sleepiness scale scores, 152 (77%) reported high Pittsburgh Sleep Quality Index scores, and 162 (82%) reported high FSS scores. Correlation analysis correcting for body mass index and sleep apnea revealed a moderate positive correlation between MGQOL-15, MG-ADL, and FSS.

CONCLUSIONS

There is a moderate positive correlation between various MG-specific outcome measures and fatigue severity.

Pathophysiology of Neuromuscular Respiratory Diseases

Gas exchange between the atmosphere and the human body depends on the lungs and the function of the respiratory pump. The respiratory pump consists of the respiratory control center located in the brain, bony rib cage, diaphragm, and intercostal, accessory, and abdominal muscles. A variety of muscles serve to fine-tune adjustments of ventilation to metabolic demands. Appropriate evaluation and interventions can prevent respiratory complications and prolong life in individuals with neuromuscular diseases. This article discusses normal function of the respiratory pump, general pathophysiologic issues, and abnormalities in more common neuromuscular diseases.

Comorbid Sleep Disturbances in Neurologic Disorders

PURPOSE OF REVIEW

This article provides a review of disturbances of sleep comorbid with common neurologic disorders.

RECENT FINDINGS

A wide variety of neurologic disorders are frequently complicated by comorbid sleep disturbances. In many cases, a bidirectional relationship appears to occur between sleep function and the neurologic disease, such that treatment of comorbid sleep disturbances may improve the symptoms of the neurologic disease.

SUMMARY

Neurologic disorders are often associated with abnormalities of sleep. Sleep influences the severity of both epilepsy and headache, and treatment of comorbid sleep disorders may improve seizure and headache frequency. Alzheimer disease is characterized by circadian phase delay and poor nighttime sleep and is strongly associated with obstructive sleep apnea. Parkinson disease is associated with several sleep disorders, including insomnia, restless legs syndrome, rapid eye movement (REM) sleep behavior disorder, daytime hypersomnia, and sleep-disordered breathing. Hypoventilation in amyotrophic lateral sclerosis and other neuromuscular disorders often presents initially with sleep problems, and treatment with noninvasive ventilation improves survival and quality of life.

Diagnostic Approach and Investigation in Sleep Medicine

PURPOSE OF REVIEW

This article provides a clinical approach to the appropriate investigation and diagnosis of sleep disorders commonly seen by neurologists.

RECENT FINDINGS

Home sleep apnea testing in appropriate situations can replace laboratory polysomnography in many cases of uncomplicated sleep apnea. Multiple sleep latency tests must be performed meticulously and interpreted in the clinical setting to avoid overdiagnoses of narcolepsy. Human leukocyte antigen testing has limited utility in establishing a diagnosis of narcolepsy because a positive test has low specificity. Rapid eye movement (REM) sleep behavior disorder is frequently the first manifestation of an evolving synucleinopathy, and a careful history and neurologic examination are needed to determine other early features of these disorders.

SUMMARY

A meticulous history from the patient, supplemented by collateral history from an observer, is essential to establishing the diagnosis of sleep disorders. Judicious supplementary use of investigations, such as laboratory polysomnography, home sleep apnea testing, wrist actigraphy, and multiple sleep latency tests, can confirm the correct diagnosis. This article describes an approach to the sleepy patient, the patient with neuromuscular disease and possible sleep-disordered breathing, the patient with restless legs syndrome, and young and older patients with abnormal movements during sleep.

Is there any relationship between quality of life and polysomnographically detected sleep parameters/disorders in stable myasthenia gravis?

It is known that quality of life in myasthenia gravis is positively correlated with subjective sleep quality, still no data is available regarding the relationship between QOL and polysomnographically detected sleep parameters and disorders. In this study, we tried to highlighten this relationship, by performing polysomnography. Sleep-related complaints were evaluated in face-to-face interviews with 19 clinically stable MG patients and 26 healthy controls. During the interviews questionnaires assessing sleep quality, excessive daytime sleepiness, fatigue, depression, anxiety, and Turkish version of the MG-QOL 15-item scale [(MG-QOL15(T)] were administered and then an overnight polysomnography was performed. Sleep disorders, especially obstructive sleep apnea and fatigue were higher, whereas subjective sleep duration was significantly lower, in patients than controls. Excessive daytime sleepiness and poor sleep quality were not different between patients and controls. Other than percentage of sleep stage III, which was negatively correlated with MG-QOL15(T) scores, neither other sleep parameters nor sleep disorders were correlated with MG-QOL15(T) scores. MG composite, subjective sleep duration, fatigue severity and Hamilton depression rating scale scores were found to be positively correlated with MG-QOL15(T) scores. It was shown that decreasing disease severity and enhancing psychological well-being will improve patients' quality of life. We recommend that our findings should be repeated in a large prospective cohort of MG patients.

The clinical usefulness of a self-administered questionnaire for sleep-disordered breathing in patients with neuromuscular disease

Background

Patients with neuromuscular disease (NMD) are at risk of developing sleep-disordered breathing (SDB) with hypercapnic respiratory failure. We hypothesised that a self-administered questionnaire (SiNQ-5 scores) may be useful to assess patients who are established on treatment for NMD with SDB.

Methods

Patients attending a tertiary referral centre filled in the SiNQ-5 (range 0-10 points, lower scores indicating fewer symptoms). The questionnaire contains five questions related to breathlessness, sleep and posture. Patients with NMD and treated SDB were compared to NMD without SDB, to sleep apnoea, chronic obstructive pulmonary disease (COPD) and heart failure (HF) patients' scores, as well as a group of patients without SDB. Results were compared using Kruskal-Wallis one-way analysis of variance, with Dunn/Bonferroni post-hoc tests if comparisons were found to be statistically significant.

Results

A total of 265 (156 male) patients completed the assessment, 40 had NMD with treated SDB [SiNQ-5 score 3.4 (3.0) points], 11 had NMD without SDB [2.7 (2.9) points], 120 patients had obstructive sleep apnoea (OSA) [4.1 (2.6) points], 16 had COPD [3.9 (3.0) points] and 9 had HF [3.2 (2.8) points], 69 patients had other conditions with no evidence of SDB [3.0 (2.4) points; P=0.077]. Patients with NMD without SDB and those with SDB who were on treatment did not differ in their responses (P=0.417). Question #1 allowed discrimination between patients with NMD with SDB [0.8 (0.8) points] and other disorders without respiratory involvement [0.3 (0.6) points; P=0.024].

Conclusions

The SiNQ-5 scores in neuromuscular patients with SDB who are established on treatment and NMD patients without SDB, as well as in patients with other conditions leading to SDB are similar.

Excessive daytime sleepiness in a patient with coexisting myotonic dystrophy type 1, myasthenia gravis and Graves' disease

A 41-year-old female with history of Graves' disease, bilateral cataract, paroxysmal atrial fibrillation was admitted because of muscle weakness, daytime sleepiness, fatigability, drowsiness, bilateral eyelid ptosis, descending of head and lower jaw. On neurological examination the patient was presented with muscle weakness, muscle atrophy (in face and sternocleidomastoid muscles), features of myotonia and apocamnosis (orbicular muscles). Electromyography revealed myopathic changes, myotonic and pseudomyotonic discharges, positive repetitive nerve stimulation test in proximal muscles. Myotonic dystrophy (MD) diagnosis was confirmed by genetic testing and myasthenia gravis (MG) by a positive titer of cholinergic receptor autoantibodies. In the CSF concentration of hypocretin was significantly decreased.