Exploring obstructive sleep apnea and sleep architecture in Parkinson's disease motor subtypes

INTRODUCTION

Parkinson's disease (PD) can be divided into motor subtypes: postural instability/gait difficulty (PIGD), tremor dominant, and indeterminate. This study aimed to assess differences in sleep structure and obstructive sleep apnea (OSA) between the PIGD and non-PIGD subtypes.

METHODS

PD participants with or without OSA (defined as apnea-hypopnea index (AHI) ≥ 15 events/hour on overnight polysomnography) were included. Patients were separated into two groups: PIGD and non-PIGD. Linear regression was used to explore differences in sleep, AHI, and other respiratory parameters between groups (adjusted for variables determined a priori). Logistic regression adjusted for the same variables was used to determine if the proportion of patients with OSA differed across groups. Subset analyses were performed: subset 1 excluding patients on psychoactive medication; subset 2 excluding patients taking levodopa or dopaminergic agonists (DAs) at nighttime and subset 3 excluding patients on either of the abovementioned drugs.

RESULTS

146 participants were studied. The non-PIGD group had less N3 sleep compared to the PIGD group (12.4% vs 16.9% p = 0.06), reaching significance in subsets 1 and 3. The AHI was significantly lower in the PIGD group (p = 0.047), including when medication effects were removed (p < 0.05). OSA was more frequent in the non-PIGD group, but only significantly in subset 3 (adjusted OR 0.3, p = 0.04).

CONCLUSION

OSA may be more severe in non-PIGD subtypes, and more frequent, in a subset free of psychoactive medication, and of levodopa and DAs, possibly owing to motor complications and dyskinesia. Future studies are required to confirm this.

Sleep spindle density and temporal clustering are associated with sleep-dependent memory consolidation in Parkinson's disease

STUDY OBJECTIVES

Sleep is required for successful memory consolidation. Sleep spindles, bursts of oscillatory activity occurring during non-REM sleep, are known to be crucial for this process and, recently, it has been proposed that the temporal organization of spindles into clusters might additionally play a role in memory consolidation. In Parkinson's disease, spindle activity is reduced, and this reduction has been found to be predictive of cognitive decline. However, it remains unknown whether alterations in sleep spindles in Parkinson's disease are predictive of sleep-dependent cognitive processes like memory consolidation, leaving open questions about the possible mechanisms linking sleep and more general cognitive state in Parkinson's patients.

METHODS

The current study sought to fill this gap by recording overnight polysomnography and measuring overnight declarative memory consolidation in a sample of thirty-five Parkinson's patients. Memory consolidation was measured using a verbal paired-associates task administered before and after the night of recorded sleep.

RESULTS

We found that lower sleep spindle density at frontal leads during non-REM stage 3 was associated with worse overnight declarative memory consolidation. We also found that patients who showed less temporal clustering of spindles exhibited worse declarative memory consolidation.

CONCLUSIONS

These results suggest alterations to sleep spindles, which are known to be a consequence of Parkinson's disease, might represent a mechanism by which poor sleep leads to worse cognitive function in Parkinson's patients.

Home Noninvasive Ventilation in COPD

Evidence is increasing that long-term noninvasive ventilation (LTNIV) can improve outcomes in individuals with severe, hypercapnic COPD. Although the evidence remains unclear in some aspects, LTNIV seems to be able to improve patient-related and physiologic outcomes like dyspnea, FEV1 and partial pressure of carbon dioxide (Pco2) and also to reduce rehospitalizations and mortality. Efficacy generally is associated with reduction in Pco2. To achieve this, an adequate interface (mask) is essential, as are appropriate ventilation settings that target the specific respiratory physiologic features of COPD. This will ensure comfort, synchrony, and adherence that will result in physiologic improvements. This article briefly reviews the newest evidence and current guidelines on LTNIV in severe COPD. It describes an actual patient who benefitted from the therapy. Finally, it provides strategies for initiating and optimizing this LTNIV in COPD, discussing high-pressure noninvasive ventilation, optimization of triggering, and control of inspiratory time. As demand increases, clinicians will need to be familiar with this therapy to reap its benefits, because inadequately adjusted LTNIV will not be tolerated or effective.

Searching for EGF Fragments Recreating the Outer Sphere of the Growth Factor Involved in Receptor Interactions

The aims of this study were to determine whether it is possible to use peptide microarrays obtained using the SPOT technique (immobilized on cellulose) and specific polyclonal antibodies to select fragments that reconstruct the outer sphere of proteins and to ascertain whether the selected peptide fragments can be useful in the study of their protein-protein and/or peptide-protein interactions. Using this approach, epidermal growth factor (EGF) fragments responsible for the interaction with the EGF receptor were searched. A library of EGF fragments immobilized on cellulose was obtained using triazine condensing reagents. Experiments on the interactions with EGFR confirmed the high affinity of the selected peptide fragments. Biological tests on cells showed the lack of cytotoxicity of the EGF fragments. Selected EGF fragments can be used in various areas of medicine.

Long term effects of continuous positive airway pressure treatment of obstructive sleep apnea-hypopnea syndrome in multiple sclerosis patients

BACKGROUND

Obstructive sleep apnea-hypopnea (OSAH) is common in MS patients and is associated with fatigue. We recently published a randomized, controlled trial (RCT) of active vs sham continuous positive airway pressure (CPAP) treatment in MS patients with fatigue, poor sleep quality, and (OSAH) (Mult Scl J 2022;28:82-92). Our aim was to evaluate the long-term effects of CPAP treatment on fatigue (Fatigue Severity Scale, FSS, primary outcome) and other clinical outcomes in MS patients with OSAH.

METHODS

Following the RCT, participants were offered treatment with CPAP and participation in an open label study. Patients were re-evaluated with RCT outcome measures at least 6 months after completion of the RCT.

RESULTS

Twenty-eight of 34 (82 %) RCT-completers participated in this study a mean of 2.7 years after the RCT. Sixteen (57 %) patients were treated with CPAP (mean use 5.4 ± 1.0 h/night during the 6 months prior to follow-up visit), while the other 12 patients declined CPAP use and received no other OSAH treatments. Baseline clinical characteristics, including MS related disability and sleep outcomes, were not significantly different between CPAP-treated vs non-CPAP treated patients. Patients using CPAP at follow-up (n = 16) demonstrated significant improvements from RCT baseline in FSS (p = 0.005), Fatigue Scale for Motor and Cognitive Functions (p = 0.008, p = 0.012), Pittsburgh Sleep Quality Index (p = 0.016), Center of Epidemiological Studies-Depression Scale (p = 0.05), and Multiple Sclerosis Quality of Life-54 (MSQOL-54) physical and mental component scores (p = 0.012, p = 0.023), but no improvements in Epworth Sleepiness Scale, Pain Visual Analog Scale, or Expanded Disability Status Scale. Patients not using CPAP (n = 12) had no significant improvements in outcome measures. Using a linear mixed model, FSS (p = 0.03), morning fatigue (p = 0.048), and MSQOL-54 physical component score (p = 0.02) improved significantly in CPAP treated patients compared with non-CPAP treated patients from RCT baseline.

CONCLUSION

In this post-RCT open label study, long-term CPAP use was associated with improved fatigue (FSS, our primary outcome) and physical quality of life in MS patients with OSAH.

Mortality in individuals with COPD on long-term home non-invasive ventilation

BACKGROUND

Real-world evidence regarding survival of patients with chronic obstructive pulmonary disease (COPD) using chronic non-invasive ventilation (NIV) is scarce.

RESEARCH QUESTION

How do obesity and other factors relate to mortality in patients with COPD on chronic NIV?

STUDY DESIGN

and Methods: We retrospectively analyzed data from COPD patients enrolled in a home ventilation program between 2014 and 2018. Survival was compared between obese and non-obese groups using the Kaplan-Meier method. Factors associated with mortality were identified using multivariable Cox proportional regression analyses with Least Absolute Selection and Shrinkage Operator (LASSO) regularization. Univariable analyses were also done stratified by obesity.

RESULTS

Median survival was 80.0 (95% CI: 71.0-NA) months among obese (n = 205) and 30.0 (95%CI: 19.0-42.0) months in non-obese (n = 61) patients. NIV adherence was high in both groups. Mortality was associated with male gender [HR 1.44], chronic opioids or benzodiazepines use [HR 1.07], home oxygen use [HR 1.82], fixed pressure mode of ventilation [HR 1.55], NIV inspiratory pressure [HR 1.05], and thoracic cancer [HR 1.27]; obesity [HR: 0.43], age [HR 0.99] and NIV expiratory pressure [HR 0.94] were associated with decreased mortality. In the obese, univariable analyses revealed that chest wall disease, thoracic cancer, home oxygen use, FEV1% predicted, and ventilation parameters were associated with mortality. In the non-obese, male gender and respiratory comorbidities were related to mortality.

INTERPRETATION

Obesity is associated with improved survival in COPD patients highly adherent to NIV. Other factors associated with mortality reflect disease severity and ventilator parameters, with differences between obese and non-obese patients.

Bestatin as a treatment modality in experimental periodontitis

BACKGROUND

Chronic periodontitis (CP), the most prevalent dysbiotic bacteria-driven chronic inflammatory disease, is an underestimated global health problem in itself, and due to a causative relationship with other disorders such as cardiovascular diseases or Alzheimer disease. The CP pathogenesis is primarily driven by Porphyromonas gingivalis in humans, and Porphyromonas gulae in dogs. These microorganisms initiate a pathogenic shift in the composition of the tooth-surface microflora. Our objective was to evaluate antimicrobial effects of bestatin, a potential CP drug candidate.

METHODS

We evaluated bestatin bacteriostatic efficiency against periodontopathogens in planktonic cultures via microplate assay, and mono- and multispecies oral biofilm models. Neutrophil bactericidal activities, such as phagocytosis, were investigated in vitro using granulocytes isolated from the peripheral blood. The therapeutic efficacy and the immunomodulatory function of bestatin was assessed in a murine model of CP.

RESULTS

Bestatin exhibited bacteriostatic activity against both P. gingivalis and P. gulae, and controlled the formation and species composition of the biofilm. We demonstrated that bestatin promotes the phagocytosis of periodontopathogens by neutrophils. Finally, we found that providing bestatin in the animal feed prevented alveolar bone resorption.

CONCLUSIONS

We show that in a murine model of CP bestatin not only shifted the biofilm species composition from pathogenic to a commensal one, but also promoted bacteria clearance by immune cells and alleviated inflammation. Taken together, these results suggest that bestatin is a promising drug choice for the treatment and/or prevention of periodontitis and clinical trials are required to fully evaluate its potency.

Noninvasive Home Mechanical Ventilation for Stable Hypercapnic COPD: A Clinical Respiratory Review from Canadian Perspectives

Acute short-term noninvasive ventilation (NIV) for hypercapnic respiratory failure in chronic obstructive pulmonary disease (COPD) has well-established benefits; however, the role of long-term home NIV remains controversial. In the past decade, studies utilizing aggressive NIV settings to maximally reduce carbon dioxide levels (PaCO2) have resulted in several positive clinical trials and led to updated guidelines on home NIV for stable hypercapnic COPD patients. This clinical respiratory review discusses the high-intensity NIV approach, summarizes recent key trials and guidelines pertaining to home NIV in COPD, and considers key clinical questions for future research and application in the Canadian context. With recent evidence and Canadian Thoracic Society (CTS) guidelines supporting the use of NIV in carefully selected COPD patients with persistent daytime hypercapnia, we believe it is time to reconsider our approach.

Adherence to continuous positive airway pressure for the treatment of obstructive sleep apnea in neurodegenerative diseases: A systematic review

Obstructive sleep apnea (OSA) is prevalent in patients with neurodegenerative diseases and is associated with worse outcomes. Positive airway pressure therapy has the potential to benefit these patients but can be challenging in this population. Our primary aim was to describe positive pressure therapy adherence. Secondarily, we aimed at identifying identify predictors of adherence to treatment in adults with neurodegenerative diseases and OSA, and report the effect of PAP adherence on outcomes such as cognitive function, quality of life and patient/caregiver satisfaction. We performed a systematic review of the literature and identified seventeen studies, eight reporting on adults with obstructive sleep apnea and mild cognitive impairment (MCI) and/or Alzheimer's disease (AD), 6 with Parkinson's disease (PD), and 3 with multiple system atrophy (MSA). Meta-analyses were not performed due to lack of systematic and standardized reporting of the primary outcome. Study duration ranged from 6 weeks to an average of 3.3 years. PAP adherence definition was widely variable between studies. Attrition rates ranged from 12% to 75%. In MCI/AD, adherence rates ranged from 28% to 61% (study duration range: 3 weeks to 3.3 years). Younger age, race (white) and better CPAP confidence scores at 1 week were associated with more CPAP use while APOE4 positive and unmarried individuals were more likely to abandon CPAP. In most studies, adherent patients had improvement in excessive daytime sleepiness, depressive symptoms, sleep quality, ability to manage daily activities and certain aspects of cognition (composite score or global cognition, psychomotor speed, executive function), as well as less cognitive decline over time. Caregiver satisfaction was also better in PAP adherent patients in one study. In PD, 15-25% of individuals refused treatment with PAP upfront, and attrition ranged from 8 to 75%. Adherent patients used their device for an average of 3h27 to 5h12 per night (study duration range: 6 weeks to 12 months). Longer disease duration, worse motor symptoms or sleep quality and lower % of REM sleep were identified as predictors of lower PAP adherence in a preliminary study, while race (non-white) and sex (women) were linked to lower adherence in a large retrospective study. In the study reporting the highest attrition rate (75%), individuals had lower educational levels. PAP adherence improved daytime sleepiness, anxiety symptoms, sleep architecture and quality and global non-motor symptoms. However, in one short-term (3 weeks) study, there was no improvement in neuropsychological testing composite score. Three studies on MSA patients suffering from sleep-disordered breathing showed that most patients are accepting of PAP (69-72%) with an average nightly use of 4h42 to 6h18. Floppy epiglottis was more frequently seen in patients discontinuing PAP in one study. In one study, four adults with MSA and long-term PAP use reported better sleep and improved vigilance. Survival time was no different between treated and untreated individuals. In conclusion, PAP therapy is challenging in patients with OSA and NDD, as evidenced by the considerable attrition and low adherence rates reported in this systematic review. There is emerging evidence proposing OSA a treatable target to prevent clinical and functional deterioration in patients with neurodegenerative diseases and addressing potential barriers to PAP adherence is paramount to maximize adherence. Our systematic review outlines several of these potential barriers, underscoring the need for future studies to standardize the definition of and explore long-term adherence to PAP therapy and assess interventions that can optimize adherence in this patient population.

Sleep electroencephalography biomarkers of cognition in obstructive sleep apnea

Obstructive sleep apnea has been associated with cognitive impairment and may be linked to disorders of cognitive function. These associations may be a result of intermittent hypoxaemia, sleep fragmentation and changes in sleep microstructure in obstructive sleep apnea. Current clinical metrics of obstructive sleep apnea, such as the apnea-hypopnea index, are poor predictors of cognitive outcomes in obstructive sleep apnea. Sleep microstructure features, which can be identified on sleep electroencephalography of traditional overnight polysomnography, are increasingly being characterized in obstructive sleep apnea and may better predict cognitive outcomes. Here, we summarize the literature on several major sleep electroencephalography features (slow-wave activity, sleep spindles, K-complexes, cyclic alternating patterns, rapid eye movement sleep quantitative electroencephalography, odds ratio product) identified in obstructive sleep apnea. We will review the associations between these sleep electroencephalography features and cognition in obstructive sleep apnea, and examine how treatment of obstructive sleep apnea affects these associations. Lastly, evolving technologies in sleep electroencephalography analyses will also be discussed (e.g. high-density electroencephalography, machine learning) as potential predictors of cognitive function in obstructive sleep apnea.

An overview of the effects of levodopa and dopaminergic agonists on sleep disorders in Parkinson's disease

Sleep disorders are among the most common nonmotor symptoms in Parkinson's disease and are associated with reduced cognition and health-related quality of life. Disturbed sleep can often present in the prodromal or early stages of this neurodegenerative disease, rendering it crucial to manage and treat these symptoms. Levodopa and dopaminergic agonists are frequently prescribed to treat motor symptoms in Parkinson's disease, and there is increasing interest in how these pharmacological agents affect sleep and their effect on concomitant sleep disturbances and disorders. In this review, we discuss the role of dopamine in regulating the sleep-wake state and the impact of neurodegeneration on sleep. We provide an overview of the effects of levodopa and dopaminergic agonists on sleep architecture, insomnia, excessive daytime sleepiness, sleep-disordered breathing, rapid eye movement sleep behavior disorder, and restless legs syndrome in Parkinson's disease. Levodopa and dopaminergic drugs may have different effects, beneficial or adverse, depending on dosing, method of administration, and differential effects on the different dopamine receptors. Future research in this area should focus on elucidating the specific mechanisms by which these drugs affect sleep in order to better understand the pathophysiology of sleep disorders in Parkinson's disease and aid in developing suitable therapies and treatment regimens.

CITATION

Scanga A, Lafontaine A-L, Kaminska M. An overview of the effects of levodopa and dopaminergic agonists on sleep disorders in Parkinson's disease. J Clin Sleep Med. 2023;19(6):1133-1144.

Associations between sleep-related symptoms, obesity, cardiometabolic conditions, brain structural alterations and cognition in the UK biobank

OBJECTIVES

Sleep disturbances are increasingly recognized as adversely affecting brain health in aging. Our aim was to investigate interrelations between subjective sleep-related symptoms, obesity, cardiometabolic disorders, brain structure and cognitive decline in a population-based aging sample.

METHODS

Data were extracted from the UK Biobank for anthropometric and demographic information, self-reported sleep behaviours, cardiometabolic measures, structural brain magnetic resonance imaging and cognitive test scores. "Sleep-related symptoms" (SRS) were measured using four questionnaire items: loud snoring, daytime sleepiness, likelihood to nap and difficulty getting up in the morning. Associations were tested using a structural equation model (SEM), adjusted for confounders. Further, multiple regression analysis was used to test for direct relationships between SRS and specific cognitive domains.

RESULTS

Among 36,468 participants with an average age of 63.6 (SD 7.5) years and 46.7% male, we found that SRS were associated with obesity and several pre-existing cardiometabolic disturbances. In turn, cardiometabolic disorders were associated with increased white matter hyperintensities and cortical thinning, which were related to cognitive dysfunction. SRS were also directly related to several structural brain changes and to cognitive dysfunction. Regression analyses showed that SRS were directly associated with slower reaction times, and lower scores in fluid intelligence, working memory and executive function.

CONCLUSIONS

Self-reported sleep-related symptoms were associated with cognitive dysfunction directly and through pre-existing cardiometabolic disorders and brain structural alterations. These findings provide evidence that symptoms of sleep disturbances, here defined primarily by hypersomnolence and snoring, are important risk factors or markers for cognitive dysfunction in an aging population.

Validation of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL screening tools for identification of obstructive sleep apnea in patients with Parkinson disease

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is common in Parkinson disease (PD). Questionnaires can be used as screening tools and have been used as a surrogate definition of OSA in large-scale research. This study aimed to validate the performance of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL and OSA predictors as tools to identify OSA in PD.

METHODS

Data were analyzed from a PD cohort study in which OSA was diagnosed using laboratory polysomnography. We calculated sensitivity and specificity of each questionnaire for OSA using different definitions and performed receiver operating characteristics curve analysis. Linear regression was used to assess adjusted associations between questionnaires and outcomes: Montreal Cognitive Assessment, Epworth Sleepiness Scale, and Movement Disorder Society revision of the Unified Parkinson Disease Rating Scale.

RESULTS

Questionnaire data were available for 68 PD patients (61.8% male, mean age 64.5 [standard deviation 9.9] years, and Hoehn and Yahr score 2.1 [0.8]). OSA (apnea-hypopnea index ≥ 15 events/h) occurred in 69.4% of participants. STOP-B28 ≥ 2 presented a higher sensitivity for OSA than STOP ≥ 2 (0.76 vs 0.65, respectively) and slightly lower specificity (0.65 vs 0.70, respectively). GOAL ≥ 2 had the highest sensitivity but poor specificity. Loud snoring had sensitivity 0.63 and specificity 0.65. STOP and snoring were significantly associated with Montreal Cognitive Assessment, Epworth Sleepiness Scale, and Movement Disorder Society revision of the Unified Parkinson Disease Rating Scale (total, motor, and nonmotor); STOP-BANG, STOP-BAG, and STOP-B28 showed associations with most outcomes, but the GOAL showed none.

CONCLUSIONS

The STOP-B28 followed by STOP and presence of loud snoring alone seem to have the best overall properties to identify PD patients with OSA, whose clinical characteristics differ from the general population with OSA.

CITATION

Gomes T, Benedetti A, Lafontaine A-L, Kimoff RJ Robinson A, Kaminska M. Validation of STOP, STOP-BANG, STOP-BAG, STOP-B28, and GOAL screening tools for identification of obstructive sleep apnea in patients with Parkinson disease. J Clin Sleep Med. 2023;19(1):45-54.

Carbamylation of Integrin IIb 3: The Mechanistic Link to Platelet Dysfunction in ESKD

BACKGROUND

Bleeding diatheses, common among patients with ESKD, can lead to serious complications, particularly during invasive procedures. Chronic urea overload significantly increases cyanate concentrations in patients with ESKD, leading to carbamylation, an irreversible modification of proteins and peptides.

METHODS

To investigate carbamylation as a potential mechanistic link between uremia and platelet dysfunction in ESKD, we used liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to quantify total homocitrulline, and biotin-conjugated phenylglyoxal labeling and Western blot to detect carbamylated integrin α IIb β 3 (a receptor required for platelet aggregation). Flow cytometry was used to study activation of isolated platelets and platelet-rich plasma. In a transient transfection system, we tested activity and fibrinogen binding of different mutated forms of the receptor. We assessed platelet adhesion and aggregation in microplate assays.

RESULTS

Carbamylation inhibited platelet activation, adhesion, and aggregation. Patients on hemodialysis exhibited significantly reduced activation of α IIb β 3 compared with healthy controls. We found significant carbamylation of both subunits of α IIb β 3 on platelets from patients receiving hemodialysis versus only minor modification in controls. In the transient transfection system, modification of lysine 185 in the β 3 subunit was associated with loss of receptor activity and fibrinogen binding. Supplementation of free amino acids, which was shown to protect plasma proteins from carbamylation-induced damage in patients on hemodialysis, prevented loss of α IIb β 3 activity in vitro.

CONCLUSIONS

Carbamylation of α IIb β 3-specifically modification of the K185 residue-might represent a mechanistic link between uremia and dysfunctional primary hemostasis in patients on hemodialysis. The observation that free amino acids prevented the carbamylation-induced loss of α IIb β 3 activity suggests amino acid administration during dialysis may help to normalize platelet function.

Alveolar Ventilation-Targeted Versus Spontaneous/Timed Mode for Home Noninvasive Ventilation in Amyotrophic Lateral Sclerosis

BACKGROUND

Home noninvasive ventilation (NIV) is increasingly used in amyotrophic lateral sclerosis (ALS) to improve symptoms and survival. Our primary objective was to compare intelligent volume-assured pressure support (iVAPS) versus spontaneous/timed (S/T) modes regarding time to first change in ventilator parameters and the number of interventions over 6 months in subjects with ALS in a respiratory therapist (RT)-led program.

METHODS

In this study, 30 subjects with ALS meeting criteria for NIV initiation were randomized to iVAPS or S/T. NIV was initiated using standardized protocols targeting optimal tidal volume and comfort in a daytime session. Download data were recorded at 1 week and 1 and 6 months. Any changes in ventilator parameters were recorded.

RESULTS

Of the 30 subjects, 56.7% had bulbar onset ALS, 8 died, and 11 in each group completed the study. Median time to first parameter change was 33.5 (interquartile range [IQR] 7.7-96.0) d versus 41.0 (IQR 12.5-216.5) d for iVAPS versus S/T groups, respectively, (P = .48). The average number of RT interventions was similar between groups (1.1 ± 1.1 vs 0.9 ± 0.9 at 1 month, P = .72; 2.4 ± 2.1 vs 2.4 ± 2.3 at 6 months, P = .95, for iVAPS vs S/T, respectively). Adherence was significantly lower with iVAPS than S/T at 1 week but not at 1 or 6 months. Download parameters were similar between groups at 1 week and 6 months except for higher residual apnea-hypopnea index (AHI) and less spontaneously triggered breaths with iVAPS at 6 months.

CONCLUSIONS

The time to first change of parameters and the number of interventions at 6 months from NIV initiation were similar for the iVAPS and S/T modes in subjects with ALS. With iVAPS, adherence was lower transiently at NIV initiation, and the residual AHI was higher at 6 months. Alveolar ventilation-targeted NIV may require a longer adaptation period and result in greater upper-airway instability predominantly in patients with bulbar ALS.

Pleckstrin Levels Are Increased in Patients with Chronic Periodontitis and Regulated via the MAP Kinase-p38α Signaling Pathway in Gingival Fibroblasts

Chronic periodontitis (CP) is a bacteria-driven inflammatory disease characterized by the breakdown of gingival tissue, the periodontal ligament, and alveolar bone, leading ultimately to tooth loss. We previously reported the pleckstrin gene (PLEK) to be highly upregulated in gingival tissue of patients with CP and the only gene concurrently upregulated in other inflammatory diseases including rheumatoid arthritis and cardiovascular diseases. Using saliva from 169 individuals diagnosed with CP and healthy controls, we investigated whether pleckstrin could serve as a novel biomarker of periodontitis. Additionally, we explored signal pathways involved in the regulation of PLEK using human gingival fibroblasts (HGFs). Pleckstrin levels were significantly higher (p < 0.001) in the saliva samples of patients with CP compared to controls and closely associated with CP severity. Immunohistochemical analysis revealed the expression of pleckstrin in inflammatory cells and gingival fibroblasts of CP patients. To explore the signal pathways involved in pleckstrin regulation, we stimulated HGFs with either interleukin-1β (IL-1β) or lipopolysaccharides (LPS) alone, or in combination with inhibitors targeting c-Jun N-terminal kinase, tyrosine kinase, protein kinase C, or p38 MAP kinase. Results showed that IL-1β and LPS significantly increased PLEK mRNA and pleckstrin protein levels. VX-745, the p38 MAP kinase inhibitor significantly decreased IL-1β- and LPS-induced pleckstrin levels at both the mRNA and the protein level. Together, these findings show that pleckstrin could serve as a salivary biomarker for the chronic inflammatory disease periodontitis and a regulator of inflammation via the p38 MAP kinase pathway.

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.

Validation of home portable monitoring for the diagnosis of sleep-disordered breathing in adolescents and adults with neuromuscular disorders

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) is common in patients with neuromuscular disorders (NMD), developing before chronic hypercapnia appears. Polysomnography (PSG) is the diagnostic gold standard but is often impractical and poorly accessible for individuals with NMD. We sought to determine the diagnostic accuracy, feasibility, and patient preference of home sleep apnea testing (HSAT) compared with PSG for the detection of SDB in NMD.

METHODS

Participants with NMD at risk for SDB aged ≥ 13 years underwent HSAT followed by overnight PSG with concomitant laboratory sleep apnea testing (same device as HSAT). Sensitivity and specificity were calculated for standard apnea-hypopnea index cutoffs for mild (≥ 5 events/h), moderate (≥ 15 events/h), and severe SDB (≥ 30 events/h) and for an oxygen desaturation index ≥ 5 events/h. Receiver operating characteristic curves were built. A questionnaire assessed patient preference.

RESULTS

Of 38 participants, 73% had moderate to severe SDB and 79% had technically acceptable HSAT. For an apnea-hypopnea index ≥ 15 events/h, HSAT sensitivity and specificity were 50% and 88%, respectively. For an oxygen desaturation index ≥ 5 events/h, HSAT sensitivity and specificity were 95% and 78%, respectively. The area under the receiver operating characteristic curve for an apnea-hypopnea index ≥ 15 events/h was 0.88 (95% confidence interval, 0.69-1.00) for HSAT. The HSAT underestimated the apnea-hypopnea index from PSG (bias, -10.7 ± 15.9 events/h). HSAT was preferred to PSG by 61% of participants.

CONCLUSIONS

HSAT is feasible, preferred by patients, and reliable for detecting SDB in most patients, although it cannot definitively rule out SDB. Therefore, HSAT is a viable diagnostic approach for SDB in NMD when PSG is not feasible, recognizing that it does not accurately distinguish between upper-airway obstruction and hypoventilation. Additional work is needed to further optimize home sleep testing in NMD.

CITATION

Westenberg JN, Petrof BJ, Noel F, et al. Validation of home portable monitoring for the diagnosis of sleep-disordered breathing in adolescents and adults with neuromuscular disorders. J Clin Sleep Med. 2021;17(8):1579-1590.

Effect of continuous positive airway pressure treatment of obstructive sleep apnea-hypopnea in multiple sclerosis: A randomized, double-blind, placebo-controlled trial (SAMS-PAP study)

OBJECTIVE

The aim of this study was to evaluate the effect of continuous positive airway pressure (CPAP) treatment on the Fatigue Severity Scale (FSS, preplanned primary outcome), another fatigue measure, sleep quality, somnolence, pain, disability, and quality of life in multiple sclerosis (MS) patients with obstructive sleep apnea-hypopnea (OSAH).

METHODS

In a randomized, double-blind trial (NCT01746342), MS patients with fatigue, poor subjective sleep quality, and OSAH (apnea-hypopnea index of ⩾ 15 events per hour/sleep), but without severe OSAH (apnea-hypopnea index > 30, and 4% oxygen desaturation index > 15 events/hour or severe somnolence), were randomized to fixed CPAP or sham CPAP for 6 months. Outcome assessments were performed at 3 and 6 months.

RESULTS

Of 49 randomized patients, 34 completed the protocol. Among completers, FSS did not improve with CPAP compared to sham at 6 months. FSS tended to improve (p = 0.09), and sleepiness (Epworth Sleepiness Scale) improved significantly (p = 0.03) at 3 months with CPAP compared to sham, but there were no other improvements with CPAP at either study evaluation.

CONCLUSION

In non-severe OSAH patients, CPAP did not significantly improve the primary outcome of FSS change at 6 months. In secondary analyses, we found a trend to improved FSS, and a significant reduction in somnolence with CPAP at 3 months.

MCPIP-1 Restricts Inflammation via Promoting Apoptosis of Neutrophils

Monocyte chemoattractant protein-induced protein-1 (MCPIP-1) is a potent inhibitor of inflammatory response to pathogens. Acting as endonuclease against transcripts of inflammatory cytokines or transcription factors MCPIP-1 can significantly reduce the cytokine storm, thus limiting the tissue damage. As the adequate resolution of inflammation depends also on the efficient clearance of accumulated neutrophils, we focused on the role of MCPIP-1 in apoptosis and retention of neutrophils. We used peritoneal neutrophils from cell-specific MCPIP-1 knockout mice and showed prolonged survival of these cells. Moreover, we confirmed that MCPIP-1-dependent degradation of transcripts of antiapoptotic genes, including BCL3, BCL2A1, BCL2L1, and for the first time MCL-1, serves as an early event in spontaneous apoptosis of primary neutrophils. Additionally, we identified previously unknown miRNAs as potential binding partners to the MCPIP-1 transcript and their regulation suggest a role in MCPIP-1 half-life and translation. These phenomena may play a role as a molecular switch that balances the MCPIP-1-dependent apoptosis. Besides that, we determined these particular miRNAs as integral components of the GM-CSF-MCPIP-1 axis. Taken together, we identified the novel anti-inflammatory role of MCPIP-1 as a regulator of accumulation and survival of neutrophils that simultaneously promotes an adequate resolution of inflammation.

The Spectrum of Sleep Disorders in Parkinson Disease: A Review

There is increasing interest in the effects of sleep and sleep disturbances on the brain, particularly in relation to aging and neurodegenerative processes. Parkinson disease (PD) is the second most common neurodegenerative disorder, with growing prevalence worldwide. Sleep disorders, including sleep-disordered breathing (SDB), are among the most frequent non-motor manifestations of PD. They can substantially impair quality of life and possibly affect the course of the disease. This article reviews the etiology, implications, and management of sleep disturbances in PD, such as excessive daytime sleepiness, insomnia, restless legs syndrome, rapid eye movement sleep behavior disorder, and SDB. Also briefly explored is the potential role of sleep disorders, including SDB, in the progression of neurodegeneration.

REACTIVE-ADJUSTABLE RESTRUCTURING OF STERNUM IN RATS AFTER MODELING OF MECHANICAL LOADING IN THE BIOMECHANICAL SYSTEM "STERNUM-RIBS-SPINE"

Aim of the research - to conduct histological analysis of the sternum immature rats after modeling mechanical loading in the biomechanical system "sternum - ribs - spine". The studies were conducted on 14 rats. In 8 rats a spinal deformity was simulated according to the method of Sarwark JF et al. in our modification. In control 6 animals were used. X-ray studies were performed in the 1, 2 and 3 months after modeling, histological research was carried out in the 1 and 3 months with definition a gradation (in points) of changes in the structural elements of a sternum. Significant abnormalities were observed mainly in the intersegmental synchondrosis, areas of attachment of ribs and growth zones of the sternum segments. The cracks and crevices with adjacent degeneratively altered chondrocytes - with pycnosis or nuclear lysis form in the area of synchondrosis and places of its fusion with ossified costal cartilage. Severe disorders are observed in the growth zones of sternum body segments. The narrowing of a growth plate due to its destruction in some areas was revealed. Violations in the organization a zone of proliferation of chondrocytes, narrowing a zone of hypertrophy lead to the violation a growth process in the sternum. Reparative manifestations are present in these structures after removal of a mechanical loading, but with the partially preserved deformations of a spine, however, destructive disorders are persisting. Creation state of a prolonged mechanical loading in the "sternum - ribs - spine" system is negatively affects on the trophism and leads to degenerative changes in the bone-cartilaginous structures. Over time a tendency to decrease and develop recovery processes is observed in a case of decreasing degree of tension.

Obstructive Sleep Apnea in Neurodegenerative Disorders: Current Evidence in Support of Benefit from Sleep Apnea Treatment

Obstructive sleep apnea (OSA) is a prevalent disorder characterized by recurrent upper airway obstruction during sleep resulting in intermittent hypoxemia and sleep fragmentation. Research has recently increasingly focused on the impact of OSA on the brain's structure and function, in particular as this relates to neurodegenerative diseases. This article reviews the links between OSA and neurodegenerative disease, focusing on Parkinson's disease, including proposed pathogenic mechanisms and current knowledge on the effects of treatment.

Sleep Quality and Nocturnal Symptoms in a Community-Based COPD Cohort

Small studies have suggested that patients with chronic obstructive pulmonary disease (COPD) have poor sleep quality. Our aim was to examine the prevalence of subjective sleep-related complaints and predictors of poor sleep quality in a large community-based COPD cohort. We analyzed cross-sectional data on sleep questionnaire responses from the Canadian Cohort of Obstructive Lung Disease (CanCOLD) study, a population-based, prospective longitudinal cohort study across Canada. The cohort comprises a COPD group and two matched non-COPD (never-smokers and ever-smokers) groups. Sleep-related symptoms were assessed using questionnaires including Pittsburgh Sleep Quality Index (PSQI). A total score of PSQI > 5 is indicative of poor sleep quality. Health-related quality of life measures and the presence of mood disturbance were assessed using Short Form-36™ Health Survey (SF-36) multi-item questionnaires and Hospital Anxiety and Depression Scale (HADS), respectively. Predictors of poor sleep quality were analyzed using multivariable logistic regression analysis. Of the 1123 subjects, 263 were healthy controls, 323 at-risk controls, and 537 had COPD (297 had mild, 240 with moderate to severe disease). The mean PSQI score was not significantly different between groups. COPD patients with poor sleep quality had lower diffusion capacity, higher HADS anxiety and depression scores and lower SF-36 mental and physical component summary scores than COPD patients classified as good sleepers. The presence of restless legs and obstructive sleep apnea symptoms, waist circumference, predicted diffusion capacity and HADS anxiety and depression scores were identified as independent predictors of poor sleep quality.

P331 Application of 3-dimensional transthoracic echocardiography in the evaluation of implantable cardioverter defibrillator lead position

AIM

To evaluate of usefulness of 3-dimensional transthoracic echocardiography (3D TTE) in the assessment of ICD lead position and its relations to tricuspid valve.

METHODS

A population consisting of 44 consecutive patients with ICD was evaluated (43 – patients with HFrEF, 1 – patient with hypertrophic cardiomyopathy). 3D TTE full-volume images of the right ventricle and/or zoomed images of the tricuspid valve were obtained. Images were analysed off-line to determine the position of the device-lead in relation to the tricuspid valve leaflets. Severity of TR was estimated as not important (+, ++) and important (+++, ++++).

RESULTS

An evaluation of the device-lead position was impossible due to poor diagnostic quality of echocardiographic images in 4 patients (9%). Among 40 remaining subjects in 12 (30%) lead was in central position, without interfering with leaflet motion, in 14 (35%) - impinging on the posterior leaflet, 6 (15%) - impinging on the septal leaflet, 8 (20%) – lead was positioned near the posteroseptal commissure. Among 15 patients (38%) TR was assessed as important. There was no correlation between device-lead position and severity of TR.

CONCLUSIONS

3D TTE enables to determinate ICD-lead position and its relation to tricuspid valve. 3D TTE can explain a mechanism of associated TR in individual patients. Further studies are necessary to investigate possible relationship between lead position and TR severity.

Obstructive sleep apnea, CPAP therapy and Parkinson's disease motor function: A longitudinal study

INTRODUCTION

We aimed to assess, in patients with Parkinson's disease (PD), the association between obstructive sleep apnea (OSA), progression of motor dysfunction and the effect of OSA treatment.

METHODS

Data were analysed from a prospective cohort study of idiopathic PD patients from a movement disorders clinic. Patients found to have OSA on polysomnography (apnea-hypopnea index [AHI] ≥15 events/h, OSA+) were offered treatment using continuous positive airway pressure (CPAP). CPAP+ was defined as an average ≥ 2 h/night use at each follow-up. Motor symptoms were assessed using the motor section of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (mUPDRS) and the Timed-Up-And-Go (TUG). Follow-up times were 3, 6 and 12 months. Mixed models were constructed, adjusting for age, sex, body mass index, levodopa equivalent dose and comorbidities.

RESULTS

We studied 67 individuals (61.2% male) of mean age 64.7 years (SD = 10.1). Baseline mUPDRS was higher in OSA+ compared to OSA- (24.5 [13.6] vs. 16.2 [7.2], p < 0.001). Motor dysfunction increased at comparable rates in OSA- and OSA+CPAP-. However, in OSA+CPAP+, mUPDRS change was significantly lower compared to OSA- (β = -0.01 vs. 0.61, p = 0.03; p = 0.12 vs. OSA+CPAP- [β = 0.39]) and TUG change was lower compared to OSA+CPAP- (β = -0.01 vs. 0.13, p = 0.002; p = 0.05 vs. OSA- [β = 0.02]).

CONCLUSIONS

In this PD cohort, OSA was associated with higher baseline mUPDRS. In those with OSA, CPAP use was associated with stabilization of motor function (mUPDRS and TUG) over 12 months. These observations support further research to clarify the role of OSA in PD pathophysiology and motor dysfunction.

Fibrous Aggregates of Short Peptides Containing Two Distinct Aromatic Amino Acid Residues

The aim of the study was the assessment of the ability of short peptides to form aggregates under physiological conditions. The dipeptides studied were derived from different aromatic amino acids (heteroaromatic peptides). Tripeptides were obtained from two distinct aromatic amino acids and cysteine or methionine residue in the C-terminal, N-terminal, or central position. The ability of the peptides to form fibrous aggregates under physiological conditions was evaluated using three independent methods: the Congo Red assay, the Thioflavin T assay, and microscopic examinations using normal and polarized light. Materials potentially useful for regenerative medicine were selected based on their cytotoxicity to the endothelial cell line EA.hy 926 and physicochemical properties of films formed by peptides. The required parameters of biocompatibility were fulfilled by H-PheCysTrp-OH, H-PheCysTyr-OH, H-PheTyrMet-OH, and H-TrpTyr-OH.

Impaired Sleep Quality in COPD Is Associated With Exacerbations: The CanCOLD Cohort Study

BACKGROUND

COPD increases susceptibility to sleep disturbances, which may in turn predispose to increased respiratory symptoms. The objective of this study was to evaluate, in a population-based sample, the relationship between subjective sleep quality and risk of COPD exacerbations.

METHODS

Data were obtained from the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Participants with COPD who had completed 18 months of follow-up were included. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) and a three-factor analysis. Symptom-based (dyspnea or sputum change ≥ 48 h) and event-based (symptoms plus medication or unscheduled health services use) exacerbations were assessed. Association of PSQI with exacerbation rate was assessed by using negative binomial regression. Exacerbation-free survival was also assessed.

RESULTS

A total of 480 participants with COPD were studied, including 185 with one or more exacerbations during follow-up and 203 with poor baseline sleep quality (PSQI score > 5). Participants with subsequent symptom-based exacerbations had higher median baseline PSQI scores than those without (6.0 [interquartile range, 3.0-8.0] vs 5.0 [interquartile range, 2.0-7.0]; P = .01), and they were more likely to have baseline PSQI scores > 5 (50.3% vs 37.3%; P = .01). Higher PSQI scores were associated with increased symptom-based exacerbation risk (adjusted rate ratio, 1.09; 95% CI, 1.01-1.18; P = .02) and event-based exacerbation risk (adjusted rate ratio, 1.10; 95% CI, 1.00-1.21; P = .048). The association occurred mainly in those with undiagnosed COPD. Strongest associations were with Factor 3 (sleep disturbances and daytime dysfunction). Time to symptom-based exacerbation was shorter in participants with poor sleep quality (adjusted hazard ratio, 1.49; 95% CI, 1.09-2.03).

CONCLUSIONS

Higher baseline PSQI scores were associated with increased risk of COPD exacerbation over 18 months' prospective follow-up.

Evaluation of the social phobia scale and social interaction anxiety scale as assessments of performance and interaction anxiety

The DSM-5 classification of performance anxiety as distinct from social anxiety underlines the need for specific measurement instruments. The Social Phobia Scale (SPS) and Social Interaction Anxiety Scale (SIAS) are widely used assessments of performance and general interaction anxiety, yet few studies have examined their criterion validity using actual performance and interaction stressors. The current study is the first to assess the scales' convergent and discriminant validity using multimodal anxiety indices including psychophysiological reactivity, which is a key characterizing feature of performance anxiety. Ninety-three individuals completed the SPS and SIAS and participated in performance and interaction challenges. Anxiety response was assessed with criterion measures of self-reported anxiety, observer-rated anxiety, heart rate and skin conductance. Both scales were moderately correlated with self-report and observer-rated anxiety (r's = 0.21-0.62) and weakly correlated with physiological measures (r's = 0.07-0.35), generally supporting convergent criterion validity. Discriminant criterion validity was not supported, however, with the SIAS and SPS showing similar correlations with each criterion measure for both social challenges. These findings suggest the SIAS and SPS are valid instruments for the assessment of social anxiety but may not be suitable for the specific measurement of performance and interaction anxiety.

FM2-7 Paediatric robot-assisted DBS surgery: electrode problems and revision techniques

Objectives

We review our cases of hardware problems requiring revision surgery and consider the technical aspects of revising the electrodes, including a frameless technique using the Renishaw Guide tubes.

Design

Retrospective Review.

Subjects

Children (≤18 years old) who presented with hardware problems following implantation of a DBS for dystonia at King’s College Hospital between May 2005 and April 2018.

Methods

Information was obtained from a prospectively kept database.

Results

Of 166 paediatric patients with DBS, 25 patients had hardware problems, and of these 21 (13%) patients had specifically electrode problems requiring replacement/revision of one or more electrodes. 7 patients had high impedances requiring revision, without obvious lead migration of fracture. 7 patients had lead migration and a further 7 patients had a lead fracture with or without lead migration. 15 patients had original DBS insertion with the Leksell Stereotactic System utilising the Medtronic Stimlock for lead fixation. 6 patients had DBS inserted with the Renishaw Sterotactic Robot and utilised the Renishaw Guide Tubes, in these patients who required lead replacement it was possible to revise the electrode without using stereotactic apparatus. As the guide tubes are implanted in the correct trajectory it is possible to measure the distance required to advance/implant the lead within this to target without the need for full stereotactic reimplantation.

Conclusions

Electrode dysfunction is relatively common in children with DBS and a systematic approach is required to identify the cause. When an electrode requires repositioning or replacement, the procedure can be performed in the conventional manner with a stereotactic frame, or freehand without a frame if a Renishaw Guide tube is used at time of first insertion.

Actigraphy-measured nocturnal wrist movements and assessment of sleep quality in patients with bullous pemphigoid: a pilot case-control study

BACKGROUND

Bullous pemphigoid (BP) is a distressing autoimmune bullous disease strongly associated with severe pruritus; however, data concerning pruritus in BP are still scarce. No clinical research evaluating the effect of BP on sleep quality has been conducted.

AIM

To evaluate the intensity of pruritus measured by nocturnal wrist movements (NWMs) and the sleep quality in patients with BP using actigraphy in comparison with nonpruritic healthy controls (HCs) with subsequent correlations with an itch visual analogue scale (VAS) as a subjective measure, disease severity [Bullous Pemphigoid Disease Area Index (BPDAI), urticaria/erythema, erosions/blisters] and serum total IgE level.

METHODS

In total, 31 patients with newly diagnosed BP (mean ± SD age 75.4 ± 12.3 years) and 40 nonpruritic HCs (age 73.5 ± 11.7 years) were recruited. All participants wore a sleep monitor (ActiSleep+) on the dominant wrist.

RESULTS

For patients with BP, median VAS score was 5.5 and median BPDAI was 43 (urticaria/erythema BPDAI was 16, erosions/blisters BPDAI was 29). Scratching, defined as bouts of NWMs, was significantly (P < 0.001) more intensive in patients with BP than in controls. Characteristic of BP was that scratching bouts corresponded with the slowest wrist movements. There were no correlations with VAS, BPDAI or total IgE level. Compared with HCs, patients with BP presented significant (P < 0.001) sleep disturbances, as determined by sleep efficiency, waking after sleep onset and average duration of awakening, and these were strongly correlated with urticaria/erythema BPDAI.

CONCLUSION

Nocturnal wrist movements measured by actigraphy are more intensive in patients with BP than in nonpruritic HCs, and characteristically slow movements. Actigraphy method showed very low sleep quality in patients with BP, thus severity of BP has a negative impact on sleep.

Monitoring Cough Effectiveness and Use of Airway Clearance Strategies: A Canadian and UK Survey

BACKGROUND

Regular monitoring combined with early and appropriate use of airway clearance can reduce unplanned hospital admissions for patients with neuromuscular disease (NMD) and spinal cord injury (SCI). We aimed to describe and compare knowledge of guidelines, monitoring of cough effectiveness, clinician prescription/provision of airway clearance strategies, and service provision constraints in the United Kingdom and Canada.

METHODS

This was a cross-sectional survey of clinicians affiliated with NMD and SCI clinics in Canada, 2016 attendees at the Home Mechanical Ventilation Conference in the United Kingdom, and United Kingdom physiotherapist networks.

RESULTS

We received 155 surveys (92 from Canada; 63 from the United Kingdom). More UK respondents (76%) were aware of airway clearance guidelines than Canadian (56%) respondents (P = .02). Routine assessment of cough effectiveness was reported by more UK respondents (59%) than Canadian (42%) respondents (P = .044). Cough peak flow (CPF) was the most common method used in both countries, although it was more commonly used in the UK (96%) than in Canada (81%, P = .02). Fewer Canadian respondents reported using CPF before initiation of airway clearance (81% vs 94%, P = .046), and fewer Canadian respondents showed results to patients for technique feedback (76% vs 97%, P = .007). Similar participant numbers reported using CPF after initiation to ensure adequate technique (73% vs 72%, P = .92). Mechanical insufflation-exsufflation (MI-E) + lung volume recruitment (LVR) + manually assisted cough when CPF ≤ 270 L/min was most routinely recommended (41% overall). Monotherapy was infrequent (LVR 15%, manually assisted cough 7%, and MI-E 4%). More Canadians identified constraints on service provision, specifically insufficient public funding for equipment (68% vs 39%, P = .002) and inadequate community workers' knowledge (56% vs 34%, P = .002). Funding for community support was a common constraint in both countries (49% vs 42%).

CONCLUSIONS

The somewhat variable cough effectiveness monitoring and airway clearance practices identified in this survey confirm the need for further work on knowledge translation related to guideline recommendations and the need to address common constraints to optimal service delivery.

Mutual Neutralization of O^{-} with O^{+} and N^{+} at Subthermal Collision Energies

We have measured total absolute cross sections for the mutual neutralization (MN) of O^{-} with O^{+} and N^{+}. A fine resolution (of about 50 meV) in the kinetic energy spectra of the product neutral atoms allows unique identification of the atomic states participating in the mutual neutralization process. Cross sections and branching ratios have also been calculated down to 1 meV center-of-mass collision energy for these two systems, with a multichannel Landau-Zener model and an asymptotic method for the ionic-covalent coupling matrix elements. The importance of two-electron processes in one-electron transfer is demonstrated by the dominant contribution of a core-excited configuration of the nitrogen atom in N^{+}+O^{-} collisions. This effect is partially accounted for by introducing configuration mixing in the evaluation of coupling matrix elements.

Change in Cognition and Other Non-Motor Symptoms With Obstructive Sleep Apnea Treatment in Parkinson Disease

STUDY OBJECTIVES

Parkinson disease (PD) non-motor symptoms are associated with sleep disorders and impair quality of life. Our objective was to assess the effect of obstructive sleep apnea (OSA) treatment using continuous positive airway pressure (CPAP) on PD non-motor symptoms.

METHODS

In this prospective observational study, 67 patients with idiopathic PD underwent polysomnography. Those with moderate-severe OSA were offered CPAP therapy. Subjects were divided into those without OSA (OSA-), and those with OSA (OSA+). Analyses were conducted for 6 and 12 months' follow-up data. At 6 months, those who had used CPAP at home for at least 1 month were considered CPAP users (OSA+CPAP+), whereas those who did not try it, or declined further treatment following a short trial were considered non-users (OSA+CPAP-). For the 12-month analysis, only those still actively using CPAP at 12 months were included in the OSA+CPAP+ group. Non-motor symptom measurements were: Epworth Sleepiness Scale, Montreal Cognitive Assessment (MoCA), Unified Parkinson's Disease Rating Scale part 1 (UPDRS1), Parkinson's Disease Sleep Scale (PDSS), Fatigue Severity Scale, Apathy Scale, Beck Depression Inventory, and Hospital Anxiety and Depression Scale (HADS).

RESULTS

Sixty-five participants were re-assessed at least once. At 6 months, 30 participants were categorized as OSA+CPAP+, 11 OSA+CPAP-, and 18 OSA-. At 12 months, 21 were categorized as OSA+CPAP+, 21 OSA+CPAP-, and 17 OSA-. The UPDRS1 and PDSS improved from baseline in OSA+CPAP+ at 6 months (-2.7, standard deviation [SD] 4.0, P = .001, and 7.9, SD 19.0, P = .03, respectively) and 12 months (-4.1, SD 5.4, P = .002, and 11.4, SD 24.4, P = .04, respectively), but not in other groups. The MoCA and HADS-A improved in OSA+CPAP+ at 12 months (1.7, SD 3.5, P = .04, and -2.1, SD 3.8, P = .02, respectively). The MoCA improved in those with low baseline MoCA and those with REM sleep behavior disorder. Mean CPAP use in users at 12 months was 3 hours 36 minutes per night.

CONCLUSIONS

CPAP treatment of OSA in PD is associated with improved overall non-motor symptoms, sleep quality, anxiety, and global cognitive function over a 12-month period.

Search for Fibrous Aggregates Potentially Useful in Regenerative Medicine Formed under Physiological Conditions by Self-Assembling Short Peptides Containing Two Identical Aromatic Amino Acid Residues

This study investigates the propensity of short peptides to self-organize and the influence of aggregates on cell cultures. The dipeptides were derived from both enantiomers of identical aromatic amino acids and tripeptides were prepared from two identical aromatic amino acids with one cysteine or methionine residue in the C-terminal, N-terminal, or central position. The formation or absence of fibrous structures under physiological conditions was established using Congo Red and Thioflavine T assays as well as by microscopic examination using normal and polarized light. The in vitro stability of the aggregates in buffered saline solution was assessed over 30 days. Materials with potential for use in regenerative medicine were selected based on the cytotoxicity of the peptides to the endothelial cell line EA.hy 926 and the wettability of the surfaces of the films, as well as using scanning electron microscopy. The criteria were fulfilled by H-dPhedPhe-OH, H-dCysdPhedPhe-OH, H-CysTyrTyr-OH, H-dPhedPhedCys-OH, H-TyrTyrMet-OH, and H-TyrMetTyr-OH. Our preliminary results suggest that the morphology and cell viability of L919 fibroblast cells do not depend on the stereochemistry of the self-organizing peptides.

Optimal method for assessment of respiratory muscle strength in neuromuscular disorders using sniff nasal inspiratory pressure (SNIP)

Background

The ability to accurately determine respiratory muscle strength is vitally important in patients with neuromuscular disorders (NMD). Sniff nasal inspiratory pressure (SNIP), a test of inspiratory muscle strength, is easier to perform for many NMD patients than the more commonly used determination of maximum inspiratory pressure measured at the mouth (MIP). However, due to an inconsistent approach in the literature, the optimal technique to perform the SNIP maneuver is unclear. Therefore, we systematically evaluated the impact of performing the maneuver with nostril contralateral to the pressure-sensing probe open (SNIP_OP) versus closed (SNIP_CL), on determination of inspiratory muscle strength in NMD patients as well as control subjects with normal respiratory muscle function.

Methods

NMD patients (n = 52) and control subjects without respiratory dysfunction (n = 52) were studied. SNIP_OP, SNIP_CL, and MIP were measured during the same session and compared using ANOVA. Agreement and bias were assessed with intraclass correlation coefficients (ICC) and Bland-Altman plots.

Results

Mean MIP values were 58.2 and 94.0 cmH2O in NMD and control subjects, respectively (p<0.001). SNIP_CL was greater than SNIP_OP in NMD (51.9 ±31.0 vs. 36.9 ±25.4 cmH₂O; p<0.001) as well as in controls (89.2 ±28.1 vs. 69.2 ±29.2 cmH₂O; p<0.001). In both populations, the ICC between MIP and SNIP_CL (NMD = 0.78, controls = 0.35) was higher than for MIP and SNIP_OP (NMD = 0.53, controls = 0.06). In addition, SNIP_CL was more often able to exclude inspiratory muscle weakness than SNIP_OP.

Conclusions

SNIP_CL values are systematically higher than SNIP_OP in both normal subjects and NMD patients. Therefore, SNIP_CL is a useful complementary test for ruling out inspiratory muscle weakness in individuals with low MIP values.

Reduced cognitive function in patients with Parkinson disease and obstructive sleep apnea

OBJECTIVE

To assess the association between obstructive sleep apnea (OSA) and nonmotor symptoms (NMS), including cognitive dysfunction, in patients with Parkinson disease (PD).

METHODS

Patients with idiopathic PD, recruited from a movement disorder clinic, underwent overnight polysomnography. OSA was defined as an apnea-hypopnea index (AHI) ≥15/h. PD severity was assessed using the Hoehn & Yahr (H&Y) scale and the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS). NMS were assessed using the Montreal Cognitive Assessment (MoCA), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale, Apathy Scale, Beck Depression Inventory, Hospital Depression and Anxiety Scale, and PD sleep Scale.

RESULTS

Sixty-seven patients (61.2% male), mean age 64.4 (SD 9.9) years and motor MDS-UPDRS 21.9 (12.6) using levodopa equivalent dose (LED) 752.4 (714.6) mg/d, were studied. OSA occurred in 47 patients (61.6%, mean AHI 27.1/h, SD 20.2/h), and NMS in 57 patients (85%). ESS and MoCA were associated with the AHI (ESS β = 0.0670, p = 0.031; MoCA β = -0.0520, p = 0.043, adjusted for age, sex, body mass index, LED, and H&Y). ESS was associated with respiratory arousals (β = 0.1015, p = 0.011) and intermittent hypoxemia (β = 0.1470, p = 0.006). MoCA was negatively associated with respiratory arousals (β = -0.0596, p = 0.049) but not intermittent hypoxemia.

CONCLUSIONS

OSA is associated with sleepiness and cognitive dysfunction in PD, suggesting that OSA may be a reversible contributor to these NMS. Further studies will be required to evaluate whether OSA treatment can improve excessive sleepiness and cognitive dysfunction in PD.