Sleep disorders in patients with spinal cord injury

Cardiac autonomic nervous activity during different sleep stages in individuals with spinal cord injury: The influence of physical training

OBJECTIVE

The present study assessed the influence of physical training on cardiac autonomic activity in individuals with spinal cord injury (SCI) during different sleep stages.

METHODS

Twenty-six volunteers were allocated into three groups: 9 sedentary individuals without SCI (control, CON); 8 sedentary tetraplegic individuals with chronic SCI (SED-SCI); 9 physically trained tetraplegic individuals with chronic SCI (TR-SCI). All participants underwent nocturnal polysomnography to monitor sleep stages: wakefulness, non-rapid eye movement (NREM) sleep (N1, N2, and N3 stages), and REM sleep. The electrocardiography data obtained during this exam were extracted to analyze the heart rate variability (HRV).

RESULTS

Sleep stages influenced HRV in the time [RR interval and root mean square of successive RR interval differences (RMSSD)] and frequency [low-frequency (LF) and high-frequency (HF) powers and LF-to-HF ratio] domains (P < 0.05). SED-SCI individuals showed unchanged HRV compared to CON (P > 0.05). When comparing the TR-SCI and SED-SCI groups, no significant differences in HRV were reported in the time domain (P > 0.05). However, in the frequency domain, more accentuated HF power was observed in TR-SCI than in SED-SCI individuals during the N2 and N3 stages and REM sleep (P < 0.05). Moreover, TR-SCI had higher HF power than CON during the N3 stage (P < 0.05).

CONCLUSIONS

TR-SCI individuals have greater HF power, indicative of parasympathetic modulation, than sedentary (injured or not injured) individuals during different sleep stages. Therefore, enhanced parasympathetic activity induced by physical training may improve cardiac autonomic modulation during sleep in individuals with chronic SCI.

Sleep Quality in Team USA Olympic and Paralympic Athletes

Adequate sleep is crucial for elite athletes' recovery, performance readiness, and immune response. Establishing reference ranges for elite athletes enables appropriate contextualization for designing and targeting sleep interventions.

PURPOSE

To establish sleep-quality reference ranges for Olympic and Paralympic cohorts using the Pittsburgh Sleep Quality Index (PSQI) and explore differences based on sex and sport types.

METHODS

Team USA athletes (men = 805, women = 798) completed the PSQI as part of a health-history questionnaire. Descriptive statistics were used to create reference ranges and linear models, and χ2 test of independence determined differences in PSQI global and component scores between sex, games, season, and participation.

RESULTS

Six hundred thirty-two (39.43%) athletes reported poor sleep (PSQIGlobal ≥ 5). Men displayed later bedtimes (P = .006), better global PSQI scores, shorter sleep latency, less sleep disturbance, and less use of sleep medication than women (all P < .001). Winter Games participants had later bedtime (P = .036) and sleep offset time (P = .028) compared with Summer Games athletes. Team-sport athletes woke earlier than individual-sport athletes (P < .001). Individual-sport athletes were more likely to have low (P = .005) and mild (P = .045) risk for reduced sleep duration than team-sport athletes.

CONCLUSION

These data provide PSQI-specific reference ranges to identify groups at greatest risk for poor sleep, who may benefit most from targeted sleep interventions.

Promotion of Para Athlete Well-being (PROPEL II): A Cross-sectional Study of Sleep in Para Athletes Across Two Nations

OBJECTIVE

Limited research exists on the sleep profiles of South African Para athletes. The aims of this study are to describe sleep quality, day-time sleepiness, and chronotype of South African Para athletes and to compare the relationship between sleep-related outcomes and demographic factors to athletes from a higher-resource country.

DESIGN

A descriptive, cross-sectional survey was conducted. Sleep-related characteristics were assessed with the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Morningness-Eveningness Questionnaire. Multiple regression models were run with and without country as independent variable.

RESULTS

One hundred twenty-four South African athletes and 52 Israeli athletes were included. Thirty percent of South African athletes presented with excessive daytime sleepiness, 35% slept 6 hrs or less per night, and 52% reported poor sleep quality. Thirty-three percent of Israeli athletes reported excessive daytime sleepiness, 29% slept 6 hrs or less, and 56% reported poor sleep quality. Chronotype was the only variable that differed significantly between countries (overrepresentation of morning types in South African athletes, and intermediate types in Israeli athletes). Intermediate chronotypes had significantly greater odds of excessive daytime sleepiness ( P = 0.007) and poor sleep quality ( P = 0.002) than morning types, irrespective of country.

CONCLUSIONS

The high prevalence of poor sleep among both South African and Israeli Para athletes warrants further investigation.

Olfactory Ensheathing Cell Ameliorate Neuroinflammation Following Spinal Cord Injury Through Upregulating REV-ERBα in Microglia

Circadian dysregulation involved in the pathophysiology of spinal cord injury (SCI). Modulation of circadian rhythms hold promise for the SCI treatment. Here, we aim to investigated the mechanism of olfactory ensheathing cells (OEC) in alleviating neuroinflammation via modulating clock gene expression in microglia. In this study, SCI rats were randomly divided into OEC group and vehicle group. At 1 day after the surgery, OECs were intravenously transplanted into OEC group SCI rat, while the rats in vehicle group received culture medium. After 7 days post of OEC transplantation, tissues were collected from the brain (prefrontal cortex, hypothalamus, spinal cord) for PCR, western blotting and immunohistochemistry (IHC) assay at zeitgeber time (ZT) 6, ZT 12, ZT 18, and ZT 24. The roles of OEC in modulating REV-ERBα in microglia were studied by experimental inhibition of gene expression and the co-culture experiment. In the vehicle group, IHC showed a significant increase of Iba-1 expression in the cerebral white matter and spinal cord compared with control group (P < 0.0001 for all comparisons). The expression of Iba-1 was significantly decreased (P < 0.0001 for all comparisons). In the OEC group, the expression of PER 1, PER 2, CLOCK, and REV-ERBα was in a rhythmical manner in both spinal cord and brain regions. SCI disrupted their typical rhythms. And OECs transplantation could modulate those dysregulations by upregulating REV-ERBα. In vitro study showed that OECs couldn't reduce the activation of REV-ERBα inhibited microglia. The intravenous transplantation of OECs can mediate cerebral and spinal microglia activation through upregulation REV-ERBα after SCI.

Association between functional outcomes and psychological variables in persons with spinal cord injury

We aimed to explore the association of functional outcomes with psychological variables, including depression, anxiety, sleep quality, and suicide risk, in persons with spinal cord injuries (SCIs). The secondary aim was to determine specific functions related to the psychological variables. This retrospective study included 259 persons with SCIs who were admitted to the Korean National Rehabilitation Center between 2019 and 2021. The participants were interviewed by a psychiatrist and completed questionnaires, including the Korean Beck Depression Inventory II (K-BDI-II), Korean Beck Anxiety Index, Insomnia Severity Index, and Mini International Neuropsychiatric Interview. To assess functional outcomes, the Spinal Cord Independence Measure III (SCIM III) and Walking Index for Spinal Cord Injury were determined by a physical therapist. The findings revealed a negative correlation of SCIM III subdivisions 1 and 3 with K-BDI-II. Specifically, feeding and mobility in bed and actions to prevent pressure injuries were functional factors associated with all four psychological variables. Our findings can guide clinicians to focus on improving functional independence and activities of daily living during the management of persons with SCI to prevent psychological consequences. Developing devices that aid in improving functional independence is crucial and may improve psychological problems in such individuals.

Efficacy of Wheelchair Skills Training Program in Enhancing Sitting Balance and Pulmonary Function in Chronic Tetraplegic Patients: A Randomized Controlled Study

Background and Objectives: This study aimed to evaluate the effectiveness of a wheelchair skills training program (WSTP) in improving sitting balance and pulmonary function in patients with chronic tetraplegia resulting from cervical spinal cord injury (cSCI). Materials and Methods: Twenty-four patients were randomly divided into WSTP and control groups. The WSTP group participated in the WSTP for eight weeks, while the control group underwent conventional physical therapy for the same eight-week period. Sitting balance was evaluated using the activity-based balance level evaluation (ABLE) scale, and pulmonary function was evaluated using forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF). Results: The WSTP group showed significant improvements in both sitting balance and pulmonary function during the intervention period (p < 0.05), whereas the control group did not show any significant changes. A strong positive correlation was found between ABLE scores and all three pulmonary function parameters across all time points. Conclusions: Our results suggest that the WSTP significantly improves sitting balance and specific aspects of lung function in patients with tetraplegia.

Learning Activities of Daily Living from Unobtrusive Multimodal Wearables: Towards Monitoring Outpatient Rehabilitation

Monitoring activities of daily living (ADLs) for wheelchair users, particularly spinal cord injury individuals is important for understanding the rehabilitation progress, customizing treatment plans, and observing the onset of secondary health conditions. This work proposes an innovative sensory system for measuring and classifying ADLs relevant to secondary health conditions. We systematically evaluated multiple wearable sensors such as pressure distribution mats on the wheelchair seat, accelerometer data from the ear and wrists, and IMU data from the wheelchair wheels to achieve the best unobtrusive combination of sensors that successfully distinguished ADLs. Our work resulted in an XGBoost classifier with a 20-second window size and extracted features in statistical, time, frequency, and wavelet domains, with an average class-wise F1 score of 82% (with only 3 out of 12 classes being mislabeled). Our study results demonstrate that the newly investigated modality of the bottom pressure mat emerges as the most relevant information source for recognizing ADLs, while heart and respiratory rates did not provide added value for the selected set of ADLs. The proposed sensory system and methodology proved high quality in most classes and easily extendable for long-term monitoring in outpatient rehabilitation, with the need for an extended database of activities.

The impact of sleep quality on health, participation and employment outcomes in people with spinal cord injury: Analyses from a large cross-sectional survey

BACKGROUND

Poor sleep is common in people with spinal cord injury (SCI), yet little is known about its impact on employment and participation outcomes.

OBJECTIVES

This study aimed to (1) describe the sleep quality of a large sample of Australians with SCI and compare the results to data from an adult control and other clinical populations; (2) examine associations between sleep quality and participant characteristics; and (3) explore the relationship between sleep and outcomes.

METHODS

Cross-sectional data from the Australian arm of the International Spinal Cord Injury (Aus-InSCI) survey from 1579 community-dwelling people aged >18 years with SCI were analysed. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Relationships between participant characteristics, sleep quality and other outcomes were examined with linear and logistic regression.

RESULTS

The PSQI was completed by 1172 individuals; 68% reported poor sleep (global PSQI score >5). Subjective sleep quality in people with SCI was poor (mean PSQI = 8.5, SD 4.5) when compared to adults without SCI (PSQI = 5.00, SD 3.37) and with traumatic brain injury (PSQI = 5.54, SD 3.94). Financial hardship and problems with secondary health conditions were significantly associated with worse sleep quality (p < 0.05). Poor sleep quality was strongly associated with lower emotional wellbeing and energy, and greater problems with participation (p < 0.001). Individuals engaged in paid work reported better sleep quality (mean PSQI = 8.1, SD 4.3) than unemployed individuals (mean PSQI = 8.7, SD 4.6; p < 0.05). Following adjustment for age, pre-injury employment, injury severity and years of education, better sleep quality remained strongly associated with being employed (OR 0.95, 95% CI 0.92 to 0.98; p = 0.003).

CONCLUSIONS

This study demonstrated pervasive and impactful relationships between sleep quality and important SCI outcomes. Poor sleep quality was strongly associated with worse emotional wellbeing and vitality, unemployment and lower participation. Future studies should aim to determine whether treating sleep problems can improve outcomes for people living with SCI.

Insomnia severity predicts depression, anxiety, and posttraumatic stress disorder in veterans with spinal cord injury or disease: a cross-sectional observational study

STUDY OBJECTIVES

To assess the association of insomnia symptoms and psychiatric symptoms in patients with spinal cord injury or disease (SCI/D).

METHODS

In this cross-sectional observational study, veterans with SCI/D (n = 72; mean = 59.85 ± 10.4 years; 92% male) completed baseline measures, including the Insomnia Severity Index (ISI) during the baseline phase of a clinical trial on treatment of sleep disorders in veterans with SCI/D. Depression severity was measured by the Patient Health Questionnaire (PHQ-9; sleep items excluded), anxiety severity was measured by the Generalized Anxiety Disorder screener (GAD-7), and probable posttraumatic stress disorder (PTSD) was measured by the Primary Care PTSD screener. Blocked regression was used to evaluate the impact of insomnia symptoms (ISI) on mental health measures after accounting for demographics and level of spinal cord injury/disease.

RESULTS

On average, participants scored in the mild range for depression (PHQ-9 = 7.4 ± 5.9) and anxiety severity (GAD-7 = 6.1 ± 6.1). In total, 36.1% (n = 26) screened positive for probable PTSD. ISI explained 19% of the variance in PHQ-9 and 20% of the variance in GAD-7 (P < .001) over and above demographics and SCI/D level of injury/disease. Odds of probable PTSD were increased 1.22-fold for each 1 unit increase in ISI (P = .001) after accounting for demographics and level of injury/disease.

CONCLUSIONS

In veterans with SCI/D, insomnia severity was linked to depression and anxiety symptom severity and risk of PTSD. Study results warrant further research to evaluate the impact of insomnia treatment on depression, anxiety, and PTSD in patients with SCI/D.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Treatment of Sleep-disordered Breathing in Patients With SCI; URL: https://clinicaltrials.gov/ct2/show/NCT02830074; Identifier: NCT02830074.

CITATION

Kelly MR, Zeineddine S, Mitchell MN, et al. Insomnia severity predicts depression, anxiety, and posttraumatic stress disorder in veterans with spinal cord injury or disease: a cross-sectional observational study. J Clin Sleep Med. 2023;19(4):695-701.

Tetraplegic obstructive sleep apnoea patients dilate the airway similarly to able-bodied obstructive sleep apnoea patients

Context/objective: Obstructive sleep apnoea (OSA) develops soon after cervical spinal cord injury (SCI) at rates higher than the general population, but the mechanisms are not understood. This study aimed to determine whether OSA in SCI is associated with altered pharyngeal muscle dilatory mechanics during quiet breathing, as has been observed in the non-SCI injured with obstructive sleep apnoea.Design: Cross sectional imaging study.Setting: Medical research institute.Participants: Eight cervical SCI patients with OSA were recruited and compared to 13 able-bodied OSA patients and 12 able-bodied healthy controls of similar age and BMI.Interventions and outcome measures: 3T MRI scans of upper airway anatomy and tagged-MRI to characterize airway muscle motion during quiet breathing were collected for analysis.Results: Considerable variation in the patterns of inspiratory airway muscle motion was observed in the SCI group, with some participants exhibiting large inspiratory airway dilatory motions, and others exhibiting counterproductive narrowing during inspiration. These patterns were not dissimilar to those observed in the able-bodied OSA participants. The increase in airway cross-sectional area of able-bodied control participants was proportional to increase in BMI, and a similar, but not significant, relationship was present in all groups.Conclusion: Despite the limited sample size, these data suggest that SCI OSA patients have heterogeneous pharyngeal dilator muscle responses to the negative pressures occurring during inspiration but, as a group, appear to be more similar to able-bodied OSA patients than healthy controls of similar age and BMI. This may reflect altered pharyngeal pressure reflex responses in at least some people with SCI.

Nocturnal bladder emptying and Quality of Life in patients with spinal cord injury

BACKGROUND

Little is known about the relationship between sleep disruption due to nocturnal bladder emptying and Quality of Life in patients with spinal cord injury.

AIM

The aim of this study was to evaluate the possible influence of number of nocturnal bladder emptying, bladder emptying method and nocturnal incontinence on the Quality of Life of patients with spinal cord injury.

DESIGN

The design of this paper is a cross-sectional descriptive study.

SETTING

The setting is in- and outpatient.

POPULATION

Seventy-nine patients aged between 18 and 77 years with SCI in a first rehabilitation period or follow-up.

METHODS

Patients were asked to complete Short Form-36 and Incontinence Quality of Life questionnaires and a medical information form. Independent samples t-tests and ANOVA were used to compare scores between groups.

RESULTS

The response rate was 71 out of 79 (89%; 51 males and 20 females). 16 paraplegic and 4 tetraplegic patients were chronic, 29 paraplegic and 22 tetraplegic patients were in rehabilitation therapy or had finished this treatment recently. The paraplegic group had a significantly better Short Form-36 total score and emotional function score, while the tetraplegic group had a significantly better Incontinence Quality of Life total score and avoidance and limiting behavior score. The paraplegic patients with 0-1 nocturnal bladder emptying had better Short Form-36-derived Quality of Life than those with ≥2 emptying. Quality of Life score was not associated with gender, leg oedema, incontinence, or acute/chronic group. Incontinence Quality of Life score was significantly better for patients with incomplete spinal cord injury. Fully completed questionnaires were returned by 36 patients; at least 1 item was missing for 35 participants.

CONCLUSIONS

General Short Form-36-derived Quality of Life was better for the paraplegic population. Incontinence-related Quality of Life was better in tetraplegic patients, most of whom used suprapubic catheterization. Paraplegic patients had compromised sleep and Quality of Life when the patient had to wake up two or more times at night to empty the bladder by voiding or intermittent catheterization. The high number of incomplete responders indicates the shortcomings of Quality-of-Life questionnaires for wheelchair-bound patients with spinal cord injury.

CLINICAL REHABILITATION IMPACT

The use of suprapubic catheterization should be considered to improve Quality of Life for tetraplegic patients. For paraplegic patients, we must focus urological policy on aiming to reduce the number of nighttime bladder emptying to one or none.

Daily Variation in Sleep Quality is Associated With Health-Related Quality of Life in People With Spinal Cord Injury

OBJECTIVE

Although sleep difficulties are common after spinal cord injury (SCI), little is known about how day-to-day fluctuations in sleep quality affects health-related quality of life (HRQOL) among these individuals. We examined the effect of sleep quality on same-day HRQOL using ecological momentary assessment methods over a 7-day period.

DESIGN

Repeated-measures study involving 7 days of home monitoring; participants completed HRQOL measures each night and ecological momentary assessment ratings 3 times throughout the day; multilevel models were used to analyze data.

SETTING

Two academic medical centers.

PARTICIPANTS

A total of 170 individuals with SCI (N=170).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Daily sleep quality was rated on a scale of 0 (worst) to 10 (best) each morning. Participants completed end-of-day diaries each night that included several HRQOL measures (Sleep Disturbance, Sleep-related Impairment, Fatigue, Cognitive Abilities, Pain Intensity, Pain Interference, Ability to Participate in Social Roles and Activities, Depression, Anxiety) and ecological momentary assessment ratings of HRQOL (pain, fatigue, subjective thinking) 3 times throughout each day.

RESULTS

Multilevel models indicated that fluctuations in sleep quality (as determined by end-of-day ratings) were significantly related to next-day ratings of HRQOL; sleep quality was related to other reports of sleep (Sleep Disturbance; Sleep-related Impairment; Fatigue) but not to other aspects of HRQOL. For ecological momentary assessment ratings, nights of poor sleep were related to worse pain, fatigue, and thinking. Generally, sleep quality showed consistent associations with fatigue and thinking across the day, but the association between sleep quality and these ecological momentary assessment ratings weakened over the course of the day.

CONCLUSIONS

Findings highlight the important association between sleep and HRQOL for people with SCI. Future work targeting sleep quality improvement may have positive downstream effects for improving HRQOL in people with SCI.

Perceived sleep problems after spinal cord injury: Results from a community-based survey in Switzerland

Objective: To investigate the burden of sleep problems within the Spinal Cord injured (SCI) community with respect to the general population (GP) in Switzerland. The study further explored potential predictors for receiving treatment for sleep problems after SCI.Design: Cross-sectional study.Setting: SCI community in Switzerland.Participants: Individuals diagnosed with an SCI, aged 16 years or older that permanently reside in Switzerland (N = 1549).Interventions: Not applicable.Outcome measures: Perceived sleep problems within the SCI community and GP. For those with sleep problems and SCI, an indicator for having received treatment was measured.Results: 58.8% of survey participants indicated having a sleep problem; 69.4% of those with a sleep problem did not indicate receiving treatment. Amongst people living with an SCI, individuals between the ages of 46-60 years (adjusted Odds Ratio, OR = 3.07; 95% CI 1.54-6.16), participants reporting severe financial hardship (OR = 2.90; 95% CI) 1.69-4.96, and those that indicated having pain (OR = 5.62; 95% CI 3.52-8.98) were more likely to have a chronic sleep problem. In comparison to the Swiss GP, the prevalence of having a sleep problem was 18% higher among persons with SCI, with the largest discrepancy for males with paraplegia between the ages of 46-60 years (Prevalence ratio, PR = 1.28; 95% CI, 1.21-1.36).Conclusion: Individuals with SCI experience more sleep problems compared to the Swiss GP. Findings from this study suggest that clinical screening for sleep issues targeting high risk groups is needed to reduce the large prevalence of non-treatment in individuals with SCI.

Detection of Sleep-Disordered Breathing in Patients with Spinal Cord Injury Using a Smartphone

Patients with spinal cord injury (SCI) have an increased risk of sleep-disordered breathing (SDB), which can lead to serious comorbidities and impact patients’ recovery and quality of life. However, sleep tests are rarely performed on SCI patients, given their multiple health needs and the cost and complexity of diagnostic equipment. The objective of this study was to use a novel smartphone system as a simple non-invasive tool to monitor SDB in SCI patients. We recorded pulse oximetry, acoustic, and accelerometer data using a smartphone during overnight tests in 19 SCI patients and 19 able-bodied controls. Then, we analyzed these signals with automatic algorithms to detect desaturation, apnea, and hypopnea events and monitor sleep position. The apnea–hypopnea index (AHI) was significantly higher in SCI patients than controls (25 ± 15 vs. 9 ± 7, p < 0.001). We found that 63% of SCI patients had moderate-to-severe SDB (AHI ≥ 15) in contrast to 21% of control subjects. Most SCI patients slept predominantly in supine position, but an increased occurrence of events in supine position was only observed for eight patients. This study highlights the problem of SDB in SCI and provides simple cost-effective sleep monitoring tools to facilitate the detection, understanding, and management of SDB in SCI patients.

Health Promotion and Wellness in Neurologic Physical Therapy: Strategies to Advance Practice

BACKGROUND AND PURPOSE

Neurologic physical therapy (PT) can assist people with neurologic conditions and injuries to optimize their health and well-being by addressing barriers at the individual, relationship, community, and societal levels. The purpose of this special interest article is to provide consensus-driven strategies to address barriers to implementing health promotion and wellness (HPW)-related neurologic PT practice.

SUMMARY OF KEY POINTS

Environmental scan, literature review, and expert input were used to determine barriers and develop strategies. Barriers include lack of time; low knowledge, self-efficacy, and awareness; client complexity; and lack of HPW resources; as well as concerns regarding payment and scope of practice. Four key strategies emerged: (1) develop and disseminate a consensus-based scope of practice for HPW in neurologic PT; (2) increase knowledge of resources related to HPW; (3) promote delivery models for HPW-related neurologic PT; and (4) encourage advocacy, community building and partnership along the continuum of care.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Clinicians should practice to their full scope of HPW-related PT practice. This includes optimizing movement, including physical activity and fitness, as well as reinforcing the importance of healthy sleep, nutrition, stress, and smoking cessation. These activities address primary, secondary, and tertiary prevention. Clinicians are encouraged to report their experiences with HPW-focused delivery models and outcomes. Additional research is needed to understand the full impact of HPW on PT practice (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A364).

A neuro-cardiac self-regulation therapy to improve autonomic and neural function after SCI: a randomized controlled trial protocol

BACKGROUND

Spinal cord injury (SCI) is associated with autonomic imbalance and significant secondary conditions, including cardiac and brain dysfunction that adversely impact health and wellbeing. This study will investigate the effectiveness (intention-to-treat) of a neuro-cardiac self-regulation therapy to improve autonomic and neural/brain activity in adults with SCI living in the community.

METHODS

A two-arm parallel, randomised controlled trial in which adults with SCI living in the community post-rehabilitation will be randomly assigned to a treatment or control group. The treatment group (N = 60) aged 18-70 years with a chronic traumatic or non-traumatic SCI, will receive intervention sessions once per week for 10 weeks, designed to regulate autonomic activity using computer-based feedback of heart rate variability and controlled breathing (called HRV-F). Comprehensive neurophysiological and psychological assessment will occur at baseline, immediate post-treatment, and 6 and 12-months post-treatment. Primary outcome measures include electrocardiography/heart rate variability (to assess autonomic nervous system function) and transcranial doppler sonography (to assess cerebral blood circulation in basal cerebral arteries). Secondary outcomes measures include continuous blood pressure, electroencephalography, functional near-infrared spectroscopy, respiration/breath rate, electrooculography, cognitive capacity, psychological status, pain, fatigue, sleep and quality of life. Controls (N = 60) will receive usual community care, reading material and a brief telephone call once per week for 10 weeks and be similarly assessed over the same time period as the HRV-F group. Linear mixed model analysis with repeated measures will determine effectiveness of HRV-F and latent class mixture modelling used to determine trajectories for primary and selected secondary outcomes of interest.

DISCUSSION

Treatments for improving autonomic function after SCI are limited. It is therefore important to establish whether a neuro-cardiac self-regulation therapy can result in improved autonomic functioning post-SCI, as well as whether HRV-F is associated with better outcomes for secondary conditions such as cardiovascular health, cognitive capacity and mental health.

TRIAL REGISTRATION

The study has been prospectively registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12621000870853 .aspx). Date of Registration: 6th July 2021. Trial Sponsor: The University of Sydney, NSW 2006. Protocol version: 22/07/2021.

Relationship Between Sleep-Disordered Breathing and Neurogenic Obesity in Adults With Spinal Cord Injury

Spinal cord injury (SCI) substantially increases the risk of neurogenic obesity, diabetes, and metabolic syndrome. Much like in the general population, a discussion of these syndromes in SCI would be incomplete without acknowledging the association of SCI with sleep-disordered breathing (SDB). This article will outline the interplay between obesity and obstructive sleep apnea (OSA), discussing the pathophysiology of obesity in OSA both for the general population and SCI population. The role of insulin resistance in SDB and SCI will also be examined. The epidemiology and pathophysiology of OSA and central sleep apnea in SCI are discussed through an examination of current evidence, followed by a review of central sleep apnea in SCI. Principles of diagnosis and management of SDB will also be discussed. Because sleep deprivation in itself can be a risk factor for developing obesity, the significance of comorbid insomnia in SCI is explored. Ultimately, a thorough sleep history, testing, and treatment are key to improving the sleep of individuals with SCI and to potentially reducing the impact of neurogenic obesity and metabolic syndrome.

Changes in sleep disturbance in patients with cervical myelopathy: comparison between surgical treatment and conservative treatment

BACKGROUND CONTEXT

The clinical symptoms of cervical myelopathy (CM) are closely associated with the risk factors of sleep disturbance, and its pathophysiological process is similar to that of spinal cord injury. Therefore, patients with CM are also expected to have sleep disturbance like patients with spinal cord injury, who typically have various types of sleep disorders. Fortunately, sleep disturbance in patients with CM is expected to respond well to treatment, and clinical studies are required to establish proper treatment strategies for CM patients with sleep disturbance.

PURPOSE

To compare the effects of CM treatment on sleep quality between patients treated surgically and those managed conservatively and to identify predictors associated with sleep improvement.

STUDY DESIGN/SETTING

Prospective cohort study.

PATIENT SAMPLE

Patients diagnosed as having CM.

OUTCOME MEASURES

Pittsburgh Sleep Quality Index (PSQI).

METHODS

The effect of CM treatment on sleep improvement at the 6-month follow-up was evaluated using a multivariate logistic regression analysis of propensity score-matched patients. To investigate factors associated with significant sleep improvement, a subgroup analysis was performed.

RESULTS

A total of 131 patients with CM and sleep disturbance were enrolled. Among these patients, 31 received surgical treatment and 100 received conservative treatment. Sleep quality improved rapidly and consistently after surgery, and significant sleep improvement was observed in most of the patients in the surgical group (26/31 patients, 83.9%) at the 6-month follow-up. However, sleep improvement only occurred in 27 (27%) of the 100 patients in the conservative group at the 6-month follow-up. The subgroup analysis revealed that the degree of CM determined by mJOA scores >13 was a significant predictor of sleep improvement after conservative treatment.

CONCLUSIONS

Clinicians should closely monitor patients with CM with sleep disturbance, and proper treatment strategies should be considered according to the severity of the conditions.

Prevalence of sleep-disordered breathing in people with tetraplegia-a systematic review and meta-analysis

STUDY DESIGN

Systematic review with meta-analysis.

OBJECTIVES

To determine the prevalence of sleep-disordered breathing (SDB) in people with tetraplegia and to identify the characteristics associated with SDB.

METHODS

A systematic literature search using Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and grey literature sources was conducted using a combination of spinal cord injury (SCI) and SDB related terms. Articles were restricted to publication dates between 1/1/2000 and 4/9/2020 and with objectively measured SDB with an overnight sleep study. The frequency of SDB stratified by the apnoea hypopnea index (AHI) was extracted and weighted averages, using a random effects model, were calculated with 95% confidence intervals. Sub-group analyses were performed where possible.

RESULTS

Twelve articles were included in the review; of these nine were included in meta-analysis (combined sample = 630). Sample sizes and case detection methods varied. Reported SDB prevalence rates ranged from 46 to 97%. The prevalence of at least mild (AHI ≥ 5), moderate (AHI ≥ 15) and severe (AHI ≥ 30) SDB were 83% (95% CI = 73-91), 59% (46-71) and 36% (26-46), respectively. Sub-group analyses found that prevalence increased with age (p < 0.001). There were no statistically significant differences in SDB prevalence by sex (p = 0.06), complete/incomplete SCI (p = 0.06), body mass index (p = 0.07), acute/chronic SCI (p = 0.73) or high/low level of cervical SCI (p = 0.90).

CONCLUSION

Our results confirm that SDB is highly prevalent in people with tetraplegia, and prevalence increases with age. The high prevalence suggests that routine screening and subsequent treatment should be considered in both acute and community care.

Risk factors for sleep disturbance in patients with cervical myelopathy and its clinical significance: a cross-sectional study

BACKGROUND CONTEXT

Sleep disturbance is highly prevalent in patients with spinal cord injury and is one of the most important clinical issues affecting their quality of life. However, it has not been properly measured or treated in patients with cervical myelopathy (CM), although most typical or atypical symptoms of CM are known to be risk factors for sleep disturbance. In addition, previous studies identified that the presence of sleep disturbance is unintentionally missed under the current evaluation process for degenerative spinal disease without direct investigation using validated tools for sleep. Therefore, studies about sleep disturbances in patients with CM are essential.

PURPOSE

The purpose of this study was to investigate the prevalence of sleep disturbance in patients with CM using validated tools and to understand its mechanism by identifying high-risk patients.

STUDY DESIGN/SETTING

Cross-sectional study.

PATIENT SAMPLE

Consecutive patients diagnosed with CM.

OUTCOME MEASURES

Pittsburgh sleep quality index.

METHODS

This study was performed on patients diagnosed with CM. Sleep disturbance was determined using the Pittsburgh sleep quality index. Variables associated with sleep disturbance including demographics, lifestyle, medical history, and radiologic parameters were investigated. Independent risk factors related to sleep disturbance were identified using multivariate logistic regression analysis.

RESULTS

A total of 203 patients with CM were included in our study. Among them, 126 patients (62.1%) were men, and the mean age was 63.0 years. Despite male predominance, sleep disturbance was identified in 71.4% of patients (145 of 203). Multivariate analysis identified a worse depression scale score, a lower modified Japanese Orthopedic Association score, chronic shoulder joint pain, smaller spinal cord area, and decreased cervical range of motion as independent risk factors for sleep disturbance.

CONCLUSIONS

In patients with CM, sleep disturbance was associated with a more severe type of myelopathy. Further studies including polysomnography and measurement of melatonin will be helpful to identify the mechanisms of the sleep disturbance in patients with CM and to improve their quality of life and clinical outcomes.

Insomnia Precipitating Events among Women Veterans: The Impact of Traumatic and Nontraumatic Events on Sleep and Mental Health Symptoms

OBJECTIVE/BACKGROUND

The current study describes insomnia precipitating events reported by women Veterans and examines differences in sleep and psychological distress variables in those who endorsed traumatic, nontraumatic, or no insomnia precipitating events.

PARTICIPANTS

Baseline data were collected from 347 women Veterans enrolled in a behavioral sleep intervention study (NCT02076165).

METHODS

Participants completed self-report measures of insomnia symptoms, sleep quality, sleep efficiency (SE), nightmare frequency, and depression and posttraumatic stress disorder (PTSD) symptoms; SE was also assessed by wrist actigraphy. Participants responded to 2 open-ended questions assessing stressful life events and health changes that coincided with insomnia symptom onset. Responses were coded as traumatic, nontraumatic, and no events. Analyses of covariance examined the effect of insomnia precipitating event type on sleep and psychological symptom variables after controlling for sociodemographic factors.

RESULTS

Overall, 25.80% of participants endorsed traumatic events, 65.80% endorsed only nontraumatic events, and 8.41% endorsed no events. Participants who endorsed traumatic events reported more severe insomnia (p = .003), PTSD (p = .001), and depression symptoms (p = .012), and poorer quality of sleep (p = .042) than participants who endorsed no events. Participants who endorsed traumatic events reported more severe PTSD symptoms (p = .004), a longer duration of sleep problems (p = .001), and poorer quality of sleep (p = .039) than participants who endorsed nontraumatic events. Participants who endorsed nontraumatic events reported more severe insomnia (p = .029) and PTSD (p = .049) symptoms than participants who endorsed no events.

CONCLUSIONS

Trauma as a precipitant for insomnia may be related to higher symptom severity in women Veterans. Implications for treatment engagement and effectiveness remain unstudied.

Sleep and the athlete: narrative review and 2021 expert consensus recommendations

Elite athletes are particularly susceptible to sleep inadequacies, characterised by habitual short sleep (<7 hours/night) and poor sleep quality (eg, sleep fragmentation). Athletic performance is reduced by a night or more without sleep, but the influence on performance of partial sleep restriction over 1-3 nights, a more real-world scenario, remains unclear. Studies investigating sleep in athletes often suffer from inadequate experimental control, a lack of females and questions concerning the validity of the chosen sleep assessment tools. Research only scratches the surface on how sleep influences athlete health. Studies in the wider population show that habitually sleeping <7 hours/night increases susceptibility to respiratory infection. Fortunately, much is known about the salient risk factors for sleep inadequacy in athletes, enabling targeted interventions. For example, athlete sleep is influenced by sport-specific factors (relating to training, travel and competition) and non-sport factors (eg, female gender, stress and anxiety). This expert consensus culminates with a sleep toolbox for practitioners (eg, covering sleep education and screening) to mitigate these risk factors and optimise athlete sleep. A one-size-fits-all approach to athlete sleep recommendations (eg, 7-9 hours/night) is unlikely ideal for health and performance. We recommend an individualised approach that should consider the athlete's perceived sleep needs. Research is needed into the benefits of napping and sleep extension (eg, banking sleep).

A review of sleep research in patients with spinal cord injury

Study design: Systematic review. Objectives: Sleep disturbances are a common complaint among individuals with spinal cord injury (SCI) and were not usually present before the SCI. Their sleep disturbances, including disrupted sleep, spasms, and problems with initiating and sustaining sleep through the night, affect SCI individuals' overall quality of life due to excessive tiredness and low energy levels during the day. Despite the high prevalence of sleep complaints in this population, current knowledge about sleep in the SCI population has not been systematically assessed. Setting: Capital Region of Denmark. Methods: We systematically reviewed literature identified from the PubMed and EMBASE databases following PRISMA guidelines.Thirty-seven articles met our inclusion criteria, as only controlled studies were included. This could be a comparison of (1) SCI individuals and able-bodied controls, (2) cervical with thoracolumbar SCI individuals, or (3) cervical, thoracolumbar SCI individuals and able-bodied controls. Results: Individuals with SCI have a higher prevalence of sleep-disordered breathing and periodic leg movements during sleep (PLMS), lower heart rate, but no nocturnal lowering of blood pressure. 24-hour energy expenditure and sleeping metabolic rate were significantly lower, and bowel movements were altered. Endocrine alterations were found in investigations of melatonin, cortisol and antidiuretic hormone. Questionnaires revealed a high prevalence of subjectively poorer sleep quality in individuals with SCI compared with able-bodied controls. Conclusions: There are significant differences between groups with SCI and able-bodied controls. SCI objectively and subjectively markedly affects an individual's sleep.

Sleep quality in individuals with short-duration chronic spinal cord injury

The aim of the study is to estimate the association between spinal cord injuries related medical factors and subjective sleep disturbance in individuals with short-duration chronic spinal cord injury. Seventy-nine individuals with traumatic spinal cord injuries were included in our study and evaluated using the Beck Depression Index for severity of depressive symptoms, Short-Form Health Survey for quality of life, Douleur Neuropathique 4 score for neuropathic pain severity, and the Pittsburgh Sleep Quality Index for subjective sleep disturbances in a tertiary rehabilitation center. Associated subjective sleep disturbance factors were predicted using multivariate binary logistic regression analysis. Subjective sleep disturbance frequency was 74.7 %, and significantly higher in individuals with paraplegia (P = 0.025, odds ratio, 9.74, 95% confidence interval, 1.21-78.14). Intermittent nighttime catheterization frequency and neuropathic pain severity levels were significantly higher in individuals with subjective sleep disturbance, and quality of life and depressive symptoms were significantly worse in individuals with subjective sleep disturbance. Poor-sleep quality was associated significantly with shorter spinal cord injury duration. The strongest associated factors for sleep disturbance were paraplegic involvement, severity of depressive symptoms (Beck Depression Index score), and quality of life (Short-Form Health Survey general health perceptions score) (odds ratio: 95% confidence interval, 29.75; 1.66-534.36, 1.47; 1.11-1.95, and 0.91; 0.85-0.97, respectively). Our study suggests that paraplegic involvement, low quality of life, and depressive mood are related to sleep disturbance in individuals with traumatic spinal cord injury.

A prospective cohort study investigating contributors to mild cognitive impairment in adults with spinal cord injury: study protocol

BACKGROUND

Studies report rates of mild cognitive impairment (MCI) in spinal cord injury (SCI) range between 10 and 60%. This broad estimate of MCI in SCI is most likely a result of: (i) inconsistent operationalization of MCI; (ii) heterogeneity among individuals with SCI; (iii) failure to account for MCI subtypes, thereby adding to the heterogeneity of samples; and, (iv) poor control for traumatic brain injury (TBI) that obscures differentiation of MCI attributable to TBI versus other factors. There is a paucity of longitudinal studies following the course of MCI in SCI, and none that account for multiple predictors of MCI, including interactions among predictors.

METHODS

An inception cohort longitudinal study will assess approximately 100 individuals aged 17-80 years with acute SCI, with measures taken at three timepoints (baseline, 3 months post-baseline, and 12 months post-injury). Data relevant to medical care received within the first 24-48 h of presentation to the emergency department will be analysed, as will measures of cognition, injury characteristics, medical history, personal factors, psychological status, psychosocial functioning, and quality of life. Latent class mixture modelling will determine trajectories for the primary outcome of interest, cognitive functioning and its subtypes, and secondary outcomes of interest such as depression. Multiple regression analyses will identify predictors of MCI and its subtypes.

DISCUSSION

The prospective design will reveal change in cognitive functioning across time and unveil different outcome trajectories; thus addressing the lack of knowledge on trajectories of MCI and MCI subtypes in SCI. Through subtyping MCI, we hope to yield groups of cognitively impaired individuals with SCI that are potentially more homogenous and thereby stable and predictable. This is the first study to capture emergency department and acute care diagnostic evidence of mild TBI, which has been poorly controlled in previous studies. Our study will also be the first to distinguish the contribution of TBI from other factors to the development of MCI in individuals with SCI.

TRIAL REGISTRATION

The study was prospectively registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12619001702101 ) on 3rd December 2019.

Cross-lagged longitudinal analysis of pain intensity and sleep disturbance

BACKGROUND

There is substantial evidence that pain intensity and sleep are related, with findings generally suggesting more support for the influence of sleep on pain intensity than vice versa. However, the strength and direction of the relationship has been found to vary among different populations, with few studies in individuals with chronic physical disabilities.

OBJECTIVE

Examine the directionality of the sleep and pain relationship in individuals with chronic physical disabilities.

METHODS

Cross-lagged effects models were generated using data from a longitudinal observational survey study of individuals (N = 1660) with multiple sclerosis (MS), muscular dystrophy (MD), post-polio syndrome (PPS), and spinal cord injury (SCI). Models evaluated the correlational effects of sleep disturbance and pain intensity, as well as the cross-lagged effects of sleep disturbance to pain intensity and vice versa.

RESULTS

The effects of pain on sleep were stronger than sleep on pain, although the magnitude of the effects were both relatively weak. Analyses within individual samples were consistent with the overall sample results for MS, MD, and PPS. In the SCI sample the magnitude and direction of the cross-lagged model paths were more variable than in the other samples.

CONCLUSIONS

The relationship between pain intensity and sleep disturbance appears bi-directional, but the effects are small in a sample of individuals with long-term disabilities. The temporal effects of pain on sleep disturbance appear stronger than the effects of sleep disturbance on pain intensity. Future research is needed to better understand this relationship in the context of pain and/or sleep disturbance treatments.

Factors influencing adherence to continuous positive airway pressure devices in individuals with spinal cord injury and sleep apnea: Results of a qualitative study

BACKGROUND

In individuals with spinal cord injury (SCI) and sleep apnea (SA), adherence to continuous positive airway pressure (CPAP) therapy seems unsatisfactory despite technical and educational support implemented when starting treatment.

OBJECTIVE

We aimed to design comprehensive model of adherence to CPAP therapy in individuals with SCI and SA.

METHODS

This was a prospective qualitative study based on semi-directed interviews and using the grounded theory as an analytic method. The theoretical framework was the social cognitive theory of Bandura. Participants were recruited from an SCI referral centre. Individuals with SCI using or having used a CPAP device for SA were included. Data were collected by semi-directed interviews on the experience of individuals with SCI regarding SA and being fitted with a CPAP device and were coded and organized into categories of experience and category relationships.

RESULTS

Among the 17 individuals included; 9 had tetraplegia; the median age was 62 (Q1-Q3 47-66) years and median time since injury was 16 (Q1-Q3 1.75-21) years. Four categories of data were identified: 1) from symptoms to validation of SA diagnosis, 2) CPAP device fitting process, 3) representations of SA, and 4) level of adherence to the treatment. In addition to the factors already observed in the general population, the proposed model identified specific adherence factors in individuals with SCI, such as physical and relational dependence on a third party, increased daily care burden and increased presence of medical devices in the daily environment.

CONCLUSION

SA and its management present certain specificities in individuals with SCI that the physician must take into account to optimize therapeutic proposals, follow-up modalities and device adherence.

Spinal Cord Injury in Rats Dysregulates Diurnal Rhythms of Fecal Output and Liver Metabolic Indicators

Spinal cord injury (SCI) dysregulates metabolic homeostasis. Metabolic homeostasis is optimized across the day by the circadian system. Despite the prevalence of metabolic pathologies after SCI, post-SCI circadian regulation of metabolism remains understudied. Here, we hypothesized that SCI in rats would disrupt circadian regulation of key metabolic organs, leading to metabolic dysregulation. Female and male Sprague-Dawley rats received moderate thoracic (T)-9 contusion SCI (or sham surgery). First, SCI disrupted diurnal rhythms in two metabolic behaviors: fecal production and food intake rhythms were ablated acutely. SCI also expedited whole-gut transit time. In parallel, acute SCI increased plasma glucose. Diurnal glucose storage-release cycles regulated by the liver were disrupted by SCI, which also increased liver glucose metabolism messenger RNAs (mRNAs). Further, SCI disrupted liver clock gene expression and suppressed inflammatory gene rhythms. Together, our novel data suggest that SCI disrupts typical metabolic and circadian function. Improving post-SCI metabolic function could enhance recovery of homeostasis.

Sleep Complaints and Sleep Quality in Spinal Cord Injury: A Web-Based Survey

STUDY OBJECTIVES

The purpose of this study was to determine sleep quality and presence of sleep disorders in participants with spinal cord injury (SCI).

METHODS

A web-based survey, available online from February 2011 to July 2013, using validated sleep questionnaires, advertised via the internet and locally through SCI consumer organizations in the United States, Australia, New Zealand, and Canada, was designed to evaluate sleep in adults with self-reported SCI. Demographic characteristics and medical history were obtained from participant self-report.

RESULTS

In our study population, 70% of the 304 participants were male with a mean age of 45 ± 13 years. The mean duration of injury was 16 ± 12 years. Cervical injuries were reported by 49% and thoracic injuries noted in 40% of participants. Increased sleep apnea risk was noted in 31% of participants, with 66% reporting snoring. Insomnia symptoms were reported by 54% of the respondents. Almost 40% of participants ranked their sleep quality as "fairly bad" to "very bad" in the previous month, 29% reported "often" or "almost always" waking up because of pain, and 22% had difficulty falling asleep because of leg cramps. In the past year, 27% of the respondents reported daily uncomfortable leg sensations and 28% found these leg symptoms to be "moderately to extremely distressing."

CONCLUSIONS

This study increases the awareness that insomnia, sleep apnea, and poor sleep quality are common in individuals with chronic SCI; often coexisting. There is a need for increased screening for sleep problems by healthcare providers taking care of individuals living with SCI.

Dim light at night impairs recovery from global cerebral ischemia

Nighttime lighting is one of the great conveniences of modernization; however, there is mounting evidence that inopportune light exposure can disrupt physiological and behavioral functions. Hospital patients may be particularly vulnerable to the consequences of light at night due to their compromised physiological state. Cardiac arrest/cardiopulmonary resuscitation (CA) was used to test the hypothesis in mice that exposure to dim light at night impairs central nervous system (CNS) recovery from a major pathological insult. Mice exposed to dim light at night (5 lx) had higher mortality in the week following cardiac arrest compared to mice housed in dark nights (0 lx). Neuronal damage was significantly greater in surviving mice exposed to dim light at night after CA versus those housed in dark nights. Dim light at night may have elevated neuronal damage by amplifying pro-inflammatory pathways in the CNS; Iba1 immunoreactivity (an indication of microglia activation) and pro-inflammatory cytokine expression were elevated in mice exposed to dim light at night post-CA. Furthermore, selective inhibition of IL-1β or TNFα ameliorated damage in mice exposed to dim light at night. The effects of light at night on CA outcomes were also prevented by using a wavelength of nighttime light that has minimal impact on the endogenous circadian clock, suggesting that replacing broad-spectrum nighttime light with specific circadian-inert wavelengths could be protective. Together, these data indicate that exposure to dim light at night after global cerebral ischemia increases neuroinflammation, in turn exacerbating neurological damage and potential for mortality.

A randomised controlled trial of nasal decongestant to treat obstructive sleep apnoea in people with cervical spinal cord injury

STUDY DESIGN

Prospective, double-blind, randomised, placebo-controlled, cross-over trial of nasal decongestion in tetraplegia.

OBJECTIVES

Tetraplegia is complicated by severe, predominantly obstructive, sleep apnoea. First-line therapy for obstructive sleep apnoea is nasal continuous positive airway pressure, but this is poorly tolerated. High nasal resistance associated with unopposed parasympathetic activation of the upper airway contributes to poor adherence. This preliminary study tested whether reducing nasal decongestion improved sleep.

SETTING

Participants' homes in Melbourne and Sydney, Australia.

METHODS

Two sleep studies were performed in participants' homes separated by 1 week. Participants were given a nasal spray (0.5 mL of 5% phenylephrine or placebo) in random order and posterior nasal resistance measured immediately. Outcomes included sleep apnoea severity, perceived nasal congestion, sleep quality and oxygenation during sleep.

RESULTS

Twelve middle-aged (average (SD) 52 (12) years) overweight (body mass index 25.3 (6.7) kg/m²) men (C4-6, AIS A and B) participated. Nasal resistance was reduced following administration of phenylephrine (p = 0.02; mean between treatment group difference -5.20: 95% confidence interval -9.09, -1.32 cmH₂O/L/s). No differences were observed in the apnoea hypopnoea index (p = 0.15; -6.37: -33.3, 20.6 events/h), total sleep time (p = 0.49; -1.33: -51.8, 49.1 min), REM sleep% (p = 0.50; 2.37: -5.6, 10.3), arousal index (p = 0.76; 1.15: -17.45, 19.75), 4% oxygen desaturation index (p = 0.88; 0.63: -23.5, 24.7 events/h), or the percentage of mouth breathing events (p = 0.4; -8.07: -29.2, 13.0) between treatments. The apnoea hypopnoea index did differ between groups, however, all except one participant had proportionally more hypopnoeas than apnoeas during sleep after decongestion.

CONCLUSIONS

These preliminary data found that phenylephrine acutely reduced nasal resistance but did not significantly change sleep-disordered breathing severity.

Actigraphy-based evaluation of sleep quality and physical activity in individuals with spinal cord injury

Study design

Cross-sectional study.

Background

Sleep disturbances are frequently reported by individuals with spinal cord injury (SCI) and are associated both with poor quality of life and reduced ability to participate in rehabilitation and daily life activities.

Objectives

This study investigated sleep quality based on self-reports and actigraphy in individuals with SCI as compared to able-bodied. We also explored the relationship between sleep quality, physical activity, and neuropathic pain.

Setting

Institute Guttmann, Neurorehabilitation Hospital, Badalona, Barcelona, Spain.

Methods

Fourteen SCI patients (12 males, 43.10 ± 10.59 y.o.) and 10 healthy individuals (7 males, mean age 46.21 ± 12.58 y.o.) were enrolled in the study. Participants wore wrist actigraphs for 7 consecutive days to characterize their sleep-wake cycle, rest-activity circadian rhythm and physical activity. Sleep quality, chronotype, daytime sleepiness, neuropathic pain severity and interference were assessed based on questionnaires.

Results

SCI individuals reported poorer sleep quality compared to healthy individuals. Actigraphy-based sleep measurements revealed that patients woke up later, spent more time in bed and slept longer compared to the healthy controls but did not differ significantly in the estimated sleep efficacy and number of awakenings from the able-bodied controls. In individuals with SCI greater physical activity predicted higher sleep efficacy and less awakening episodes as well as shorter sleep latency and lower sleep disturbance.

Conclusions

The actigraphy-based sleep estimates indicate that patients with SCI spent more time in bed and slept longer but their sleep efficacy was similar to able-bodied controls. Maintaining regular physical activity could improve pain control and sleep quality.

Impact Of Spinal Cord Injury On Sleep: Current Perspectives

Sleep disorders are commonly encountered in people living with spinal cord injury (SCI). Primary sleep disorders such as sleep-disordered breathing (SDB), sleep-related movement disorders, circadian rhythm sleep-wake disorders, and insomnia disorder are common conditions after SCI but remain under-recognized, underdiagnosed and therefore remain untreated for a majority of patients. Sleep disturbances in people living with SCI are associated with significant impairments of daytime function and quality of life. Previous reviews have described findings related mainly to SDB but have not examined the relationship between other sleep disorders and SCI. This narrative review examines various sleep abnormalities and related functional and physical impairments in people living with SCI. It discusses new evidence pertaining to management, highlights existing limitations in the literature and recommends future directions for research.

Spinal Cord Injury in Rats Disrupts the Circadian System

Spinal cord injury (SCI) perturbs many physiological systems. The circadian system helps maintain homeostasis throughout the body by synchronizing physiological and behavioral functions to predictable daily events. Whether disruption of these coordinated daily rhythms contributes to SCI-associated pathology remains understudied. Here, we hypothesized that SCI in rats would dysregulate several prominent circadian outputs including glucocorticoids, core temperature, activity, neuroinflammation, and circadian gene networks. Female and male Sprague Dawley rats were subjected to clinically relevant thoracic 9 moderate contusion SCI (or laminectomy sham surgery). Diurnal measures-including rhythms of plasma corticosterone (CORT), body temperature, and activity (using small implanted transmitters), and intraspinal circadian and inflammatory gene expression-were studied prior to and after surgery. SCI caused overall increases and disrupted rhythms of the major rodent glucocorticoid, CORT. Presurgery and sham rats displayed expected rhythms in body temperature and activity, whereas rats with SCI had blunted daily rhythms in body temperature and activity. In parallel, SCI disrupted intraspinal rhythms of circadian clock gene expression. Circadian clock genes can act as transcriptional regulators of inflammatory pathways. Indeed, SCI rats also showed dysregulated rhythms in inflammatory gene expression in both the epicenter and distal spinal cord. Our data show that moderate SCI in rats causes wide-ranging diurnal rhythm dysfunction, which is severe at acute time points and gradually recovers over time. Normalizing post-SCI diurnal rhythms could enhance the recovery of homeostasis and quality of life.

Worth the effort? Weighing up the benefit and burden of continuous positive airway pressure therapy for the treatment of obstructive sleep apnoea in chronic tetraplegia

STUDY DESIGN

Mixed methods OBJECTIVES: Continuous positive airway pressure (CPAP) therapy is the recommended treatment for obstructive sleep apnoea (OSA). The aim of this study was to estimate CPAP adherence in people with tetraplegia and OSA, and to explore the barriers and facilitators to CPAP use.

SETTING

Hospital outpatient department in Melbourne, Australia METHODS: People with chronic tetraplegia and OSA were commenced with auto-titrating CPAP and supported for 1 month. Semi-structured interviews were conducted with participants at one month and analysed thematically. CPAP usage was measured at 1, 6 and 12 months, with "adherent" defined as achieving more than 4 h average per night.

RESULTS

Sixteen participants completed the study (80% male; mean age 56 (SD = 15)). Mean nightly CPAP use at one month was 3.1 h (SD = 2.5; 38% adherent), and at 6 months and 12 months were 2.6 h (SD = 2.8; 25% adherent) and 2.1 h (SD = 3.2; 25% adherent). The perceived benefit/burden balance strongly influenced ongoing use. Burden attributed to CPAP use was common, and included mask discomfort, and physical and emotional problems. Adherent participants were motivated by the immediate daytime benefits to mood, alertness and sleepiness. There was a tendency to not recognise symptoms of OSA until after they were treated.

CONCLUSION

CPAP use is challenging for people with tetraplegia, who experience substantial burden from using the device. When tolerated, the proximate benefits are substantial. People with tetraplegia need more intensive support for longer to help them overcome the burdens of CPAP and benefit from the treatment.

Diagnostic accuracy of a two-stage model for detecting obstructive sleep apnoea in chronic tetraplegia

BACKGROUND

Obstructive sleep apnoea (OSA) is highly prevalent in people with spinal cord injury (SCI). Polysomnography (PSG) is the gold-standard diagnostic test for OSA, however PSG is expensive and frequently inaccessible, especially in SCI. A two-stage model, incorporating a questionnaire followed by oximetry, has been found to accurately detect moderate to severe OSA (MS-OSA) in a non-disabled primary care population. This study investigated the accuracy of the two-stage model in chronic tetraplegia using both the original model and a modified version for tetraplegia.

METHODS

An existing data set of 78 people with tetraplegia was used to modify the original two-stage model. Multivariable analysis identified significant risk factors for inclusion in a new tetraplegia-specific questionnaire. Receiver operating characteristic (ROC) curve analyses of the questionnaires and oximetry established thresholds for diagnosing MS-OSA. The accuracy of both models in diagnosing MS-OSA was prospectively evaluated in 100 participants with chronic tetraplegia across four international SCI units.

RESULTS

Injury completeness, sleepiness, self-reported snoring and apnoeas were included in the modified questionnaire, which was highly predictive of MS-OSA (ROC area under the curve 0.87 (95% CI 0.79 to 0.95)). The 3% oxygen desaturation index was also highly predictive (0.93 (0.87-0.98)). The two-stage model with modified questionnaire had a sensitivity and specificity of 83% (66-93) and 88% (75-94) in the development group, and 77% (65-87) and 81% (68-90) in the validation group. Similar results were demonstrated with the original model.

CONCLUSION

Implementation of this simple alternative to full PSG could substantially increase the detection of OSA in patients with tetraplegia and improve access to treatments.

TRIAL REGISTRATION NUMBER

Results, ACTRN12615000896572 (The Australian and New Zealand Clinical Trials Registry) and pre-results, NCT02176928 (clinicaltrials.gov).

Magnetic resonance imaging of the upper airway in patients with quadriplegia and obstructive sleep apnea

The aim of this study was to investigate upper airway anatomy in quadriplegics with obstructive sleep apnea. Fifty subjects were recruited from three hospitals in Australia: people with quadriplegia due to spinal cord injury and obstructive sleep apnea (n = 11), able-bodied people with obstructive sleep apnea (n = 18), and healthy, able-bodied controls (n = 19). All underwent 3-Tesla magnetic resonance imaging of their upper airway. A subgroup (n = 34) received a topical vasoconstrictor, phenylephrine and post-phenylephrine magnetic resonance imaging. Mixed-model analysis indicated no significant differences in total airway lumen volume between the three groups (P = 0.086). Spinal cord injury-obstructive sleep apnea subjects had a significantly larger volume of soft palate (P = 0.020) and retroglossal lateral pharyngeal walls (P = 0.043) than able-bodied controls. Able-bodied-obstructive sleep apnea subjects had a smaller mandible volume than spinal cord injury-obstructive sleep apnea subjects and able-bodied control subjects (P = 0.036). No differences were seen in airway length between groups when controlling for height (P = 0.055). There was a marginal increase in velopharyngeal volume across groups post-phenylephrine (P = 0.050), and post hoc testing indicated the difference was confined to the able-bodied-obstructive sleep apnea group (P < 0.001). No other upper airway structures showed significant changes with phenylephrine administration. In conclusion, people with obstructive sleep apnea and quadriplegia do not have a structurally smaller airway than able-bodied subjects. They did, however, have greater volumes of soft palate and lateral pharyngeal walls, possibly due to greater neck fat deposition. The acute response to upper airway topical vasoconstriction was not enhanced in those with obstructive sleep apnea and quadriplegia. Changes in upper airway anatomy likely contribute to the high incidence in obstructive sleep apnea in quadriplegic subjects.

Poor sleep in adults with pediatric-onset spinal cord injury: associations with pain, health, and activity

OBJECTIVE

To investigate medical complications that increase risk for poor sleep in adults with pediatric-onset spinal cord injury (SCI) and explore the relation of poor sleep to psychosocial outcomes.

METHOD

This was a cross-sectional study of individuals with pediatric-onset SCI interviewed between 2011-2015. Participants were recruited from a pediatric specialty hospital and answered questions about demographics, injury characteristics, pain, and medical complications and completed standardized outcome measures, including: Pittsburgh Sleep Quality Index, SF12v2 Health Survey, Craig Handicap Assessment and Recording Technique (CHART), and Subjective Happiness Scale.

RESULTS

The study included 180 participants between the ages of 19 and 51 (M=34.20 y; SD=7.28) who sustained their SCI before the age of 19 (M=13.48y; SD=4.59). Participants were predominantly male (62%) and Caucasian (84%). A majority had tetraplegia (56%) and complete injuries (74%). Poor sleep occurred with greater frequency in those with tetraplegia and who were unemployed. Neck (OR=2.80, P = 0.001), shoulder (OR=2.15, P = 0.011), arm (OR=3.06, P = 0.004), and lower extremity pain (OR=2.72, P = 0.004) were associated with increased risk of poor sleep. In a logistic regression analysis, chronic medical conditions and continuous pain were most likely to be associated with poor sleep. Individuals with poor sleep reported lower levels of mobility, perceived health, and subjective happiness.

CONCLUSION

Pain and secondary complications significantly increase the odds of poor sleep. Furthermore, poor sleep is associated with decreased mobility and measures of well-being. Preventive measures to reduce risk factors and improve sleep quality after pediatric-onset SCI should be considered.

Sleep disordered breathing in pregnancy: the maternal and fetal implications

Sleep disordered breathing (SDB) which includes obstructive sleep apnoea (OSA) and upper airway resistance syndrome (UARS), has emerged as a risk factor for adverse maternal-foetal outcomes in pregnancy. Physiological changes of pregnancy predispose a woman 'at risk' towards developing SDB. The increasing incidence of OSA in pregnancy closely correlates with the population trends of obesity. Common screening tools validated in non-pregnant subjects including Epworth Sleepiness Scale (ESS) and Berlin Questionnaire (BQ) are poor predictors of SDB in pregnancy. Preeclampsia, gestational hypertension and gestational diabetes mellitus (GDM) are linked with SDB. Preeclampsia and OSA share common pathological associations. It is unclear if one predisposes the other. Foetal morbidity includes intrauterine growth restriction (IUGR), preterm delivery, low birth weight, neonatal intensive care unit (NICU) admission and Apgar score of less than seven at one minute. Continuous positive airway pressure (CPAP) is a well-documented treatment of SDB in pregnancy and has been shown to reverse some of the adverse events. It becomes imperative to diagnose and manage this condition as OSA causes substantial morbidity in the untreated pregnant patient and foetus. Three short clinical cases and a literature review on SDB on pregnancy are presented.

Respiratory problems and management in people with spinal cord injury

Spinal cord injury (SCI) is characterised by profound respiratory compromise secondary to the level of loss of motor, sensory and autonomic control associated with the injury. This review aims to detail these anatomical and physiological changes after SCI, and outline their impact on respiratory function. Injury-related impairments in strength substantially alter pulmonary mechanics, which in turn affect respiratory management and care. Options for treatments must therefore be considered in light of these limitations.

KEY POINTS

Respiratory impairment following spinal cord injury (SCI) is more severe in high cervical injuries, and is characterised by low lung volumes and a weak cough secondary to respiratory muscle weakness.Autonomic dysfunction and early-onset sleep disordered breathing compound this respiratory compromise.The mainstays of management following acute high cervical SCI are tracheostomy and ventilation, with noninvasive ventilation and assisted coughing techniques being important in lower cervical and thoracic level injuries.Prompt investigation to ascertain the extent of the SCI and associated injuries, and appropriate subsequent management are important to improve outcomes.

EDUCATIONAL AIMS

To describe the anatomical and physiological changes after SCI and their impact on respiratory function.To describe the changes in respiratory mechanics seen in cervical SCI and how these changes affect treatments.To discuss the relationship between injury level and respiratory compromise following SCI, and describe those at increased risk of respiratory complications.To present the current treatment options available and their supporting evidence.

Prevalence of depression, fatigue, and sleep disturbances in patients with myelopathy: Their relation with functional and neurological recovery

OBJECTIVES

To observe the prevalence of fatigue, depression, and sleep disturbance in patients with myelopathy and their correlation with neurological and functional recovery.

PATIENTS AND METHODS

Study conducted in a university tertiary research hospital with 127 patients with myelopathy (92 males) admitted to neurorehabilitation unit between January 2010 and December 2013. Mean age was 32.71 ± 13.08 years (range 15-65 years), and mean duration of injury was 76.22 ± 82.5 days (range 14-365 days). Functional status and impairments were assessed using Barthel Index and Spinal Cord Independence Measures. Depression, fatigue, and sleep disturbances were assessed using Hospital Anxiety and Depression Scale, Fatigue Severity Scale, and Pittsburgh Sleep Quality Index scales, respectively. Neurological recovery was assessed using American Spinal Injury Association's impairment scale.

RESULTS

Forty-four out of 104 (42%) patients had borderline or confirmed depression, 36/108 (33%) had significant fatigue, and 62/106 (58%) had significant sleep disturbances at admission. Significant correlation was observed between change in fatigue and depression scores with change in functional status scores (P < 0.05) but no correlation (P > 0.05) between change in sleep disturbance scores and functional status score and neurological recovery (P > 0.05). Similarly, change in fatigue and depression scores had no correlation with neurological status improvement. Fatigue, depression, and sleep disturbance scores showed significant improvement, that is, admission vs. discharge scores (P < 0.05) with significant correlation between improvement in all three variables (P < 0.05).

CONCLUSIONS

Study variables showed significant improvement in the present study with myelopathy patients but not necessarily correlating with functional and neurological recovery.

High nasal resistance is stable over time but poorly perceived in people with tetraplegia and obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is highly prevalent in people with tetraplegia. Nasal congestion, a risk factor for OSA, is common in people with tetraplegia. The purpose of this study was to quantify objective and perceived nasal resistance and its stability over four separate days in people with tetraplegia and OSA (n=8) compared to able-bodied controls (n=6). Awake nasal resistance was quantified using gold standard choanal pressure recordings (days 1 and 4) and anterior rhinomanometry (all visits). Nasal resistance (choanal pressure) was higher in people with tetraplegia versus controls (5.3[6.5] vs. 2.1[2.4] cmH₂O/L/s, p=0.02) yet perceived nasal congestion (modified Borg score) was similar (0.5[1.8] vs. 0.5[2.0], p=0.8). Nasal resistance was stable over time in both groups (CV=0.23±0.09 vs. 0.16±0.08, p=0.2). These findings are consistent with autonomic dysfunction in tetraplegia and adaptation of perception to high nasal resistance. Nasal resistance may be an important therapeutic target for OSA in this population but self-assessment cannot reliably identify those most at risk.

Comparison of Sleep Problems in Individuals with Spinal Cord Injury and Multiple Sclerosis

STUDY OBJECTIVES

Sleep problems are common in spinal cord injury (SCI) and multiple sclerosis (MS). However, the degree to which sleep problems differ between these distinct clinical populations has not been evaluated. In this study, we examined self-reported sleep problems in individuals with SCI and those with MS, and compared these clinical groups on the Medical Outcomes Study Sleep Scale (MOS-SS).

METHODS

Participants were 1,677 individuals (SCI = 581; MS = 1,096) enrolled in longitudinal study of self-reported health outcomes in SCI and MS. Univariate and multivariate analysis of covariance examined group differences on global sleep problems and domain-specific subscales of the MOS-SS.

RESULTS

Individuals with SCI reported an average of 30 fewer min of sleep per night (Sleep Quantity subscale) and significantly greater difficulty initiating and maintaining sleep (Sleep Disturbance subscale) compared to individuals with MS. However, groups did not differ on global sleep problems (Sleep Problems Index 9).

CONCLUSIONS

Although global sleep problems are more common in SCI and MS than in the general population, these groups exhibit differing sleep problem profiles, and thus may require unique treatment approaches to address the specific domains of sleep affected. For individuals with SCI, an additional focus on increasing sleep quantity and reducing sleep disruptions may be warranted.

Louis EK. Neuromuscular disorders and sleep in critically ill patients

Sleep-disordered breathing (SDB) is a frequent presenting manifestation of neuromuscular disorders and can lead to significant morbidity and mortality. If not recognized and addressed early in the clinical course, SDB can lead to clinical deterioration with respiratory failure. The pathophysiologic basis of SDB in neuromuscular disorders, clinical features encountered in specific neuromuscular diseases, and diagnostic and management strategies for SDB in neuromuscular patients in the critical care setting are reviewed. Noninvasive positive pressure ventilation has been a crucial advance in critical care management, improving sleep quality and often preventing or delaying mechanical ventilation and improving survival in neuromuscular patients.