Respiratory insufficiency with preserved diaphragmatic function in amyotrophic lateral sclerosis

Sleep in amyotrophic lateral sclerosis: A systematic review and meta-analysis of polysomnographic findings

BACKGROUND

This study explores the polysomnographic differences between amyotrophic lateral sclerosis (ALS) patients and healthy controls.

METHODS

An electronic literature search was conducted in MEDLINE, EMBASE, All EBM databases, Web of Science, and CNKI from inception to Oct 2022.

RESULTS

Meta-analyses revealed significant reductions in sleep efficiency, total sleep time, N2%, slow wave sleep percentage, minimum SpO₂, and mean SpO₂, and increases in wake time after sleep onset and N1%, sleep latency, rapid eye movement sleep latency, time spent with SpO₂ < 90%, oxygen desaturation index, and apnea hypopnea index in ALS patients compared with controls. Sensitivity analyses showed that some heterogeneity was explained by excluding patients taking medications impacting sleep, whether studies employed an adaptation night, and the use of different PSG scoring rules.

CONCLUSIONS

Significant polysomnographic abnormalities are present in ALS. Our findings underscore the need for a comprehensive PSG assessment of sleep changes in ALS patients. When performing PSG examinations in ALS, whether the patients are taking medication impacting sleep and the scoring system used should be considered.

Rapid Eye Movement Sleep Behavior Disorder and Neurodegenerative Diseases: An Update

Rapid eye movement sleep behavior disorder (RBD) is a sleep behavior disorder characterized by abnormal behaviors and loss of muscle atonia during rapid eye movement (REM) sleep. RBD is generally considered to be associated with synucleinopathies, such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), and usually precedes years before the first symptom of these diseases. It is believed that RBD predicts the neurodegeneration in synucleinopathy. However, increasing evidences have shown that RBD is also found in non-synucleinopathy neurodegenerative diseases, including Alzheimer’s disease (AD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), etc. Sleep disturbance such as RBD may be an early sign of neurodegeneration in these diseases, and also serve as an assessment of cognitive impairments. In this review, we updated the clinical characteristics, diagnosis, and possible mechanisms of RBD in neurogenerative diseases. A better understanding of RBD in these neurogenerative diseases will provide biomarkers and novel therapeutics for the early diagnosis and treatment of the diseases.

Quality of life and functional independence in amyotrophic lateral sclerosis: A systematic review

Amyotrophic Lateral Sclerosis (ALS) leads to functional capacity decline, generating great impact in quality of life. Quality of life is directly related to physical integrity and functional independence. This systematic review aimed to analyze treatment protocols and their outcomes from clinical trials with focus on ALS rehabilitation that evaluated the effects on quality of life and functional independence from their intervention process. A literature search was conducted through MEDLINE-PubMed, Science Direct, Web of Science and Scopus databases. A total of 3630 articles were identified. Eleven studies met the inclusion criteria. They focused on different aspects of quality of life or functional independence, which are: respiratory care, mental health, communication skills and exercises. Use of bipap and inspiratory muscle training, anxiety and depression, communication devices implementation and exercises safety and tolerability were considered as key points. However, the drastic evolution of the disease is a limiting factor to the perception of quality of life improvement by patients. Further studies should be done to validate the benefits on patients' quality of life.

Unstable control of breathing can lead to ineffective noninvasive ventilation in amyotrophic lateral sclerosis

Upper airway obstruction with decreased central drive (ODCD) is one of the causes of ineffective noninvasive ventilation (NIV) in amyotrophic lateral sclerosis (ALS). The aim of this study is to determine the mechanism responsible for ODCD in ALS patients using NIV.

This is a prospective study that included ALS patients with home NIV. Severity of bulbar dysfunction was assessed with the Norris scale bulbar subscore; data on upper or lower bulbar motor neuron predominant dysfunction on physical examination were collected. Polysomnography was performed on every patient while using NIV and the ODCD index (ODCDI: number of ODCD events/total sleep time) was calculated. To determine the possible central origin of ODCD, controller gain was measured by inducing a hypocapnic hyperventilation apnoea. Sonography of the upper airway during NIV was performed to determine the location of the ODCD.

30 patients were enrolled; three (10%) had ODCDI >5 h⁻¹. The vast majority of ODCD events were produced during non-rapid eye movement sleep stages and were a consequence of an adduction of the vocal folds. Patients with ODCDI >5 h⁻¹ had upper motor neuron predominant dysfunction at the bulbar level, and had greater controller gain (1.97±0.33 versus 0.91±0.36 L·min⁻¹·mmHg⁻¹; p<0.001) and lower carbon dioxide (CO₂) reserve (4.00±0.00 versus 10.37±5.13 mmHg; p=0.043). ODCDI was correlated with the severity of bulbar dysfunction (r= −0.37; p=0.044), controller gain (r=0.59; p=0.001) and CO₂ reserve (r= −0.35; p=0.037).

ODCD events in ALS patients using NIV have a central origin, and are associated with instability in the control of breathing and an upper motor neuron predominant dysfunction at the bulbar level.

Upper airway obstructions in ALS patients using NIV have a central origin, and are associated with instability in the control of breathing and an upper motor neuron predominant dysfunction at the bulbar levelhttp://bit.ly/2WEMt28

Tracking a Fast-Moving Disease: Longitudinal Markers, Monitoring, and Clinical Trial Endpoints in ALS

Amyotrophic lateral sclerosis (ALS) encompasses a heterogeneous group of phenotypes with different progression rates, varying degree of extra-motor involvement and divergent progression patterns. The natural history of ALS is increasingly evaluated by large, multi-time point longitudinal studies, many of which now incorporate presymptomatic and post-mortem assessments. These studies not only have the potential to characterize patterns of anatomical propagation, molecular mechanisms of disease spread, but also to identify pragmatic monitoring markers. Sensitive markers of progressive neurodegenerative change are indispensable for clinical trials and individualized patient care. Biofluid markers, neuroimaging indices, electrophysiological markers, rating scales, questionnaires, and other disease-specific instruments have divergent sensitivity profiles. The discussion of candidate monitoring markers in ALS has a dual academic and clinical relevance, and is particularly timely given the increasing number of pharmacological trials. The objective of this paper is to provide a comprehensive and critical review of longitudinal studies in ALS, focusing on the sensitivity profile of established and emerging monitoring markers.

Physiological changes in neurodegeneration - mechanistic insights and clinical utility

The effects of neurodegenerative syndromes extend beyond cognitive function to involve key physiological processes, including eating and metabolism, autonomic nervous system function, sleep, and motor function. Changes in these physiological processes are present in several conditions, including frontotemporal dementia, amyotrophic lateral sclerosis, Alzheimer disease and the parkinsonian plus conditions. Key neural structures that mediate physiological changes across these conditions include neuroendocrine and hypothalamic pathways, reward pathways, motor systems and the autonomic nervous system. In this Review, we highlight the key changes in physiological processing in neurodegenerative syndromes and the similarities in these changes between different progressive neurodegenerative brain conditions. The changes and similarities between disorders might provide novel insights into the human neural correlates of physiological functioning. Given the evidence that physiological changes can arise early in the neurodegenerative process, these changes could provide biomarkers to aid in the early diagnosis of neurodegenerative diseases and in treatment trials.

Isolated rapid eye movement sleep without atonia in amyotrophic lateral sclerosis

OBJECTIVE

The aim of this study was to quantitatively analyze, with the most recent and advanced tools, the presence of periodic leg movements during sleep (PLMS) and/or rapid eye movement (REM) sleep without atonia (RSWA), in a group of patients with amyotrophic lateral sclerosis (ALS), and to assess their eventual correlation with the clinical severity of the disease.

METHODS

Twenty-nine ALS patients were enrolled (mean age 63.6 years) along with 28 age-matched "normal" controls (mean age 63.8 years). Functional impairment due to ALS was evaluated using the ALS-Functional Rating Scale-Revised (ALS-FRS) and the ALS severity scale (ALSSS). Full video polysomnographic night recordings were obtained, and PLMS were analyzed by considering their number/hour of sleep and periodicity index, the distribution of intermovement intervals, and the distribution during the night. The characteristics of the chin electromyogram (EMG) amplitude during REM sleep were analyzed by means of the automatic atonia index and the number of chin EMG activations (movements).

RESULTS

The ALS patients showed longer sleep latency than the controls, together with an increase in number of stage shifts, increased sleep stage 1, and decreased sleep stage 2. None of the leg PLMS parameters were different between the ALS patients and controls. The REM atonia index was significantly decreased in the ALS patients, and the number of chin movements/hour tended to increase. Both REM atonia index and number of chin movements/hour correlated significantly with the ALS-FRS; REM atonia was higher and chin movements were less in ALS patients with more preserved function (higher scores on the ALS-FRS).

CONCLUSION

Abnormal REM sleep atonia seemed to be a genuine effect of ALS pathology per se and correlated with the clinical severity of the disease. It is unclear if this might constitute the basis of a possible risk for the development of REM sleep behavior disorder or represent a form of isolated RSWA in ALS.

Sleep disorders and respiratory function in amyotrophic lateral sclerosis

Sleep disorders in amyotrophic lateral sclerosis (ALS) present a significant challenge to the management of patients. Issues include the maintenance of adequate ventilatory status through techniques such as non-invasive ventilation, which has the ability to modulate survival and improve patient quality of life. Here, a multidisciplinary approach to the management of these disorders is reviewed, from concepts about the underlying neurobiological basis, through to current management approaches and future directions for research.