Sleep disordered breathing following spinal cord injury

Brain tumours result in sleep disorders in children and adolescents

BACKGROUND AND OBJECTIVES

Sleep disturbances are frequently reported in children with brain tumours. The objective of our cross-sectional study was to systematically examine sleep in these children. We hypothesised that children with tumours involving the sleep-wake-regulatory areas have an altered sleep-wake-regulation.

METHODS

Sixty-one patients aged 0-18 years and with a diagnosis of a primary brain or cervical medullary tumour were included. They were categorised based upon tumour location into two groups - those affecting the sleep-wake regulatory regions, i.e. brain stem, basal forebrain, hypothalamus, thalamus, and posterior fossa compressing the brain stem and those that did not. Sleep history, questionnaire surveys, polysomnography, and multiple sleep latency test were used, as indicated clinically. Surveys included Pediatric Daytime Sleepiness Scale, Children's Sleep Habits Questionnaire, Strengths and Difficulties Questionnaire, and Pediatric Quality of Life Inventory, Multidimensional Fatigue Scale and Generic Core Scale.

RESULTS

Patients with tumours involving the sleep-wake regulatory areas were sleepier/more fatigued (p = 0.03). Sleep apnoea was observed in 86% of all the patients and comorbid narcolepsy in 8%, without group differences (p ≥ 0.12). Patients with tumours involving the sleep-wake-regulatory areas had more emotional problems (p = 0.04), were more affected by mental health problems (p < 0.001), and had poorer quality of life (p ≤ 0.03).

CONCLUSIONS

Many children with brain tumours suffer from disturbed sleep, poor mental health, and low quality of life. We recommend that systematic sleep evaluation is included in their routine care along with psychological and social support.

A Primary Care Provider's Guide to Managing Respiratory Health in Subacute and Chronic Spinal Cord Injury

Respiratory complications following spinal cord injury (SCI) have remained the leading cause of death across the lifespan and are one of the most common reasons for hospitalization. Complications from altered respiratory physiology after SCI include atelectasis, pneumonia, venous thromboembolic disease, and sleep-disordered breathing. The risk for complications is greater with higher SCI levels and severity, and mortality from pneumonia is heightened compared to the general population. Optimal primary care for individuals with SCI includes appropriate surveillance for SCI-specific respiratory disease, key preventive care including promotion of influenza immunization and respiratory muscle training, and early identification and treatment of pneumonia with institution of aggressive secretion management strategies. The respiratory physiology and specific management of respiratory complications after SCI is reviewed.

Excessive daytime sleepiness in adults with spinal cord injury and associations with pain catastrophizing and pain intensity

STUDY DESIGN

Pre-post cohort mixed factorial design.

OBJECTIVE

Excessive daytime sleepiness (EDS) and chronic pain are major problems for people with spinal cord injury (SCI). However, the relationship between chronic pain and EDS requires clarification. The goal of the study was to determine associations between pain catastrophizing (PC) and pain intensity (PI) with EDS in adults with SCI.

SETTING

New South Wales, Australia.

METHODS

Participants included 45 adults with SCI and 44 able-bodied controls. The relationship between PI, PC, and EDS was explored by determining the influence of PC and PI on the performance of both groups in a behavioral test of EDS called the Oxford Sleep Resistance Test. PC and PI were assessed by self-report. The association between EDS, pain, and other relevant factors like fatigue and mood was established using multidimensional scaling in the SCI group data.

RESULTS

PC was found to have a significant association with EDS, with 33.3% falling asleep in the SCI group with low PC, compared with 70% in those with high PC. Only 10% of the controls fell asleep regardless of PC. PI did not significantly influence EDS in either group. Multidimensional scaling showed EDS was closely related to PC, PI, pain interference, fatigue, and mood.

CONCLUSIONS

PC appears to be strongly associated with EDS in SCI. Findings suggest significant sleep benefits may occur in adults with SCI by treating cognitive biases like PC, as well as addressing associated factors like fatigue, pain interference, low mood, and so on.

Sleep-Disordered Breathing and Spinal Cord Injury: A State-of-the-Art Review

Individuals living with spinal cord injury or disease (SCI/D) are at increased risk for sleep-disordered breathing (SDB), with a prevalence that is three- to fourfold higher than the general population. The main features of SDB, including intermittent hypoxemia and sleep fragmentation, have been linked to adverse cardiovascular outcomes including nocturnal hypertension in patients with SCI/D. The relationship between SDB and SCI/D may be multifactorial in nature given that level and completeness of injury can affect central control of respiration and upper airway collapsibility differently, promoting central and/or obstructive types of SDB. Despite the strong association between SDB and SCI/D, access to diagnosis and management remains limited. This review explores the role of SCI/D in the pathogenesis of SDB, poor sleep quality, the barriers in diagnosing and managing SDB in SCI/D, and the alternative approaches and future directions in the treatment of SDB, such as novel pharmacologic and nonpharmacologic treatments.

Daytime sleepiness and its relationships to fatigue and autonomic dysfunction in adults with spinal cord injury

OBJECTIVE

To determine the extent of daytime sleepiness in adults with spinal cord injury (SCI) and investigate the contribution of fatigue and autonomic function to sleepiness status.

METHODS

Participants included 45 adults with SCI attending outpatient services or living in the community and 44 able-bodied controls. The Oxford Sleep Resistance Test (OSLER) was used to assess daytime sleepiness, while eye blink rate duration (electrooculography) and the Iowa Fatigue Scale assessed fatigue. Heart rate variability (HRV) was used to assess autonomic function. Survival analysis (Kaplan Meier) was used to estimate the rate of loss in participation in the OSLER task, as a measure of daytime sleepiness. Repeated measures ANOVA was used to determine HRV differences between groups. Regression analysis was used to establish factors that contributed to daytime sleepiness.

RESULTS

Participants with high lesions ("T3 and above") had significantly increased daytime sleepiness. OSLER results revealed only 33% of those with high lesions remained awake during the task. Those with high lesions also had significantly reduced sympathetic activity while no differences in parasympathetic activity were found between groups. Lesion completeness had no effect. Standardized variation in heart rate, slow eye blinks, low frequency HRV and self-reported fatigue contributed to daytime sleepiness.

CONCLUSION

Neurological lesions at "T3 or above" have an increased risk of daytime sleepiness, impacting on independence in daily functional tasks and work performance. Autonomic imbalance alters cardiovascular control, affecting health and wellbeing. The interaction of these factors requires further investigation.

Mid-cervical spinal cord contusion causes robust deficits in respiratory parameters and pattern variability

Mid-cervical spinal cord contusion disrupts both the pathways and motoneurons vital to the activity of inspiratory muscles. The present study was designed to determine if a rat contusion model could result in a measurable deficit to both ventilatory and respiratory motor function under “normal” breathing conditions at acute to chronic stages post trauma. Through whole body plethysmography and electromyography we assessed respiratory output from three days to twelve weeks after a cervical level 3 (C3) contusion. Contused animals showed significant deficits in both tidal and minute volumes which were sustained from acute to chronic time points. We also examined the degree to which the contusion injury impacted ventilatory pattern variability through assessment of Mutual Information and Sample Entropy. Mid-cervical contusion significantly and robustly decreased the variability of ventilatory patterns. The enduring deficit to the respiratory motor system caused by contusion was further confirmed through electromyography recordings in multiple respiratory muscles. When isolated via a lesion, these contused pathways were insufficient to maintain respiratory activity at all time points post injury. Collectively these data illustrate that, counter to the prevailing literature, a profound and lasting ventilatory and respiratory motor deficit may be modelled and measured through multiple physiological assessments at all time points after cervical contusion injury.

"To Work Just Like Anyone Else"-A Narrative from a Man Aging with Spinal Cord Injury

People aging with spinal cord injury (SCI) develop medical problems commonly associated with the aging process at a younger age than the general population. However, research about how the life story changes and how meaning will be experienced in occupations is lacking. The aim was to describe and offer an explanation of how a man experienced meaning in everyday occupations while aging with an SCI. Four narrative interviews were performed over a four-year period, with a man in his fifties, who lived with SCI for 39 years. The narrative analysis generated an overall plot, named “To Work Just Like Anyone Else,” and gives a picture of his experiences, thoughts, and reflections about meaning in occupations, from when he became injured to the present, and in relation to his future. His life story is characterized by secondary health complications, and his experiences of negotiating with the aging body and making choices to continue working. Further, how occupational risk factors, e.g., imbalance, alienation, and deprivation, occur as a result of lack of rehabilitation and support from social systems is addressed. Future research should explore how rehabilitation and social systems can support people aging with SCI to experience meaning in everyday occupations and to have balance in everyday life.

Comorbidity and physical activity in people with paraplegia: a descriptive cross-sectional study

STUDY DESIGN

Descriptive cross-sectional study.

SETTING

The study was conducted in the Spinal Cord Injury Unit of the University Vall d'Hebron Hospital and in the Physical Education and Sports Department of the University of Valencia.

OBJECTIVES

The aim of this study was to quantify the presence of comorbidities in spinal cord injury (SCI) subjects who did or did not perform regular physical activity (PA) and to identify the relationship between PA and the level of comorbidity.

METHODS

The sample consisted of patients with complete motor SCI (T2-T12), who were fitted with an accelerometer attached to the non-dominant wrist for a period of 1 week. The clinical and blood analytic variables were selected by an expert panel.

RESULTS

In the exploratory analysis, we have found differences in the total number of pathologies between active and inactive patients, with fewer total pathologies in the active patient group. An association was found between the PA level and diabetes mellitus (; P=0.047; φ=0.25). We also observed an association between the cardioprotector level of high-density lipoprotein (HDL)-cholesterol and PA level (; P=0.057; Φ0.24).

CONCLUSIONS

Our results suggest that patients considered active showed lower total comorbidity than inactive patients and higher protection levels against developing cardiovascular comorbidity.

Phrenic pacing compared with mechanical ventilation

STUDY DESIGN

Comparable case series.

OBJECTIVES

High-cervical spinal cord injury (SCI) may disrupt the ability to breathe sufficiently. To restore respiration a phrenic nerve pacer can be implanted. The aims of this study were to describe the use of phrenic nerve pacing in tetraplegics in Denmark and compare the users with a population of ventilator dependent tetraplegics.

SETTING

Clinics for Spinal Cord Injuries, and Respiratory Centre East, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.

METHODS

Nine tetraplegic individuals who had implantation of a phrenic nerve pacer and 16 home mechanical ventilator dependent tetraplegics met the inclusion criteria. Data were retrieved from medical records and a structured follow-up interview with seven individuals from each group.

RESULTS

No significant differences were found when comparing age at injury, time since injury, length of hospitalization, incidence of pneumonia, number of pneumonia hospitalizations, number of tracheal suctions, speech quality and activities of daily living or quality of life. On the Short Form Health Survey (SF36) mental health summary the median for both users of phrenic nerve pacing and users of mechanical ventilation was one s.d. above the mean of a standard population.

CONCLUSIONS

Nine people have had a phrenic nerve pacer implanted. They do not significantly differ from a group of home mechanical ventilator dependent tetraplegics on a number of performance measures, but both groups seem to have better quality of life than a standard population.

Qualitative Experience of Sleep in Individuals With Spinal Cord Injury

Poor sleep contributes to adverse health outcomes making it important to understand sleep in medically vulnerable populations, including those with spinal cord injury (SCI). However, little attention has been paid to circumstances specific to SCI that may negatively affect sleep, or to consequences of poor sleep in this population. The objective of this study was to examine the experience of sleep among individuals with SCI. Secondary analysis using thematic coding of qualitative data from an ethnographic study of community-dwelling adults with SCI was conducted. Sleep-related data were found in transcripts for 90% of the sample. Participants described diminished sleep duration and irregular sleep patterns. Several factors contributing to poor sleep were identified, including SCI-related circumstances and sleep environment. Participants also discussed how poor sleep affected occupational engagement. This study highlights the extent of sleep disturbance experienced after SCI and the subsequent impact on occupational performance, and provides direction for clinical practice.

Participation in activities and secondary health complications among persons aging with traumatic spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To describe participation in activities and explore the relationship with secondary complications among persons aging with a traumatic spinal cord injury (SCI).

SETTING

A regional SCI outpatient center in Sweden.

METHODS

Data were collected through a phone survey, which included 10 activities from the instrument PARTS/M-v3 (PARTicipation Survey/Mobility version-3) together with data from the participants' medical records. Cross-tabulation and χ² were used for data analysis.

RESULTS

In this study, 121 persons matched the inclusion criteria and the final study sample comprised 73 participants (60% response rate): 55 men and 18 women. Mean age was 63.7±9.4 years, and mean time since injury was 36.3±9.2 years. Regardless of duration of SCI, all 73 participated in dressing, bathing and leisure activities. Women reported better health than men. Particularly for those who lived 36-55 years after injury; increasing pain, fatigue, spasticity and decreased muscle strength were negatively affecting participation in activities, especially exercise and active recreation. Additionally, a need to save strength/energy was also a reason for not participating in the activities. Perceived future support and concerns in relation to personal assistance, assistive devices and rehabilitation was also reported.

CONCLUSION

Increasing secondary health complications and a need to save strength/energy influenced participation in activities. Laws and/or governmental policies regarding personal assistance and assistive devices did not always support participation in activities. Interventions should aim to create a balance among activities in everyday life.

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.

Sleep onset hypoventilation in chronic spinal cord injury

A high prevalence of sleep-disordered breathing (SDB) after spinal cord injury (SCI) has been reported in the literature; however, the underlying mechanisms are not well understood. We sought to determine the effect of the withdrawal of the wakefulness drive to breathe on the degree of hypoventilation in SCI patients and able-bodied controls. We studied 18 subjects with chronic cervical and thoracic SCI (10 cervical, 8 thoracic SCI; 11 males; age 42.4 ± 17.1 years; body mass index 26.3 ± 4.8 kg/m²) and 17 matched able-bodied subjects. Subjects underwent polysomnography, which included quantitative measurement of ventilation, timing, and upper airway resistance (R_UA) on a breath-by-breath basis during transitions from wake to stage N1 sleep. Compared to able-bodied controls, SCI subjects had a significantly greater reduction in tidal volume during the transition from wake to N1 sleep (from 0.51 ± 0.21 to 0.32 ± 0.10 L vs. 0.47 ± 0.13 to 0.43 ± 0.12 L; respectively, P < 0.05). Moreover, end-tidal CO₂ and end-tidal O₂ were significantly altered from wake to sleep in SCI (38.9 ± 2.7 mmHg vs. 40.6 ± 3.4 mmHg; 94.1 ± 7.1 mmHg vs. 91.2 ± 8.3 mmHg; respectively, P < 0.05), but not in able-bodied controls (39.5 ± 3.2 mmHg vs. 39.9 ± 3.2 mmHg; 99.4 ± 5.4 mmHg vs. 98.9 ± 6.1 mmHg; respectively, P = ns). R_UA was not significantly altered in either group. In conclusion, individuals with SCI experience hypoventilation at sleep onset, which cannot be explained by upper airway mechanics. Sleep onset hypoventilation may contribute to the development SDB in the SCI population.

Simplified Approach to Diagnosing Sleep-Disordered Breathing and Nocturnal Hypercapnia in Individuals With Spinal Cord Injury

OBJECTIVE

To evaluate a strategy of home-based testing to diagnose sleep-disordered breathing and nocturnal hypercapnia in individuals with spinal cord injury (SCI).

DESIGN

Case series.

SETTING

Referral center.

PARTICIPANTS

Adults with C1-T6 SCI (N=81). Individuals were eligible if ≥ 18 years old, with SCI of ≥ 3 months' duration, living within 100 miles of the study site, and not meeting exclusion criteria. Of the 161 individuals recruited from the SCI Model System database who were not enrolled, reasons were not interested in participating, change of location, prior positive pressure ventilation use, or medical contraindication. Ten individuals did not complete the study.

INTERVENTIONS

Performance of an unsupervised home sleep apnea test combined with transcutaneous partial pressure of carbon dioxide/oxygen saturation by pulse oximetry monitoring.

MAIN OUTCOME MEASURES

Prevalence of sleep-disordered breathing and nocturnal hypercapnia. Clinical and physiological variables were examined to determine which, if any, correlate with the severity of sleep-disordered breathing.

RESULTS

Obstructive sleep apnea (OSA) was found in 81.3% of individuals, central sleep apnea (CSA) was found in 23.8%, and nonspecific hypopnea events, where respiratory effort was too uncertain to classify, were present in 35%. Nonspecific hypopnea events correlated strongly with CSA but weakly with OSA, suggesting that conventional sleep apnea test scoring may underestimate central/neuromuscular hypopneas. Nocturnal hypercapnia was present in 28% and oxygen desaturation in 18.3%. Neck circumference was the primary predictor for OSA, whereas baclofen use and obstructive apnea/hypopnea index weakly predicted CSA. Awake transcutaneous partial pressure of carbon dioxide and CSA were only marginally associated with nocturnal hypercapnia.

CONCLUSIONS

Unsupervised home sleep apnea testing with transcutaneous capnography effectively identifies sleep-disordered breathing and nocturnal hypercapnia in individuals with SCI.

Identification and classification of involuntary leg muscle contractions in electromyographic records from individuals with spinal cord injury

Involuntary muscle contractions (spasms) are common after human spinal cord injury (SCI). Our aim was to compare how well two raters independently identified and classified different types of spasms in the same electromyographic records (EMG) using predefined rules. Muscle spasms were identified by the presence, timing and pattern of EMG recorded from paralyzed leg muscles of four subjects with chronic cervical SCI. Spasms were classified as one of five types: unit, tonic, clonus, myoclonus, mixed. In 48h of data, both raters marked the same spasms most of the time. More variability in the total spasm count arose from differences between muscles (84%; within subjects) than differences between subjects (6.5%) or raters (2.6%). Agreement on spasm classification was high (89%). Differences in spasm count, and classification largely occurred when EMG was marked as a single spasm by one rater but split into multiple spasms by the other rater. EMG provides objective measurements of spasm number and type in contrast to the self-reported spasm counts that are often used to make clinical decisions about spasm management. Data on inter-rater agreement and discrepancies on muscle spasm analysis can both drive the design and evaluation of software to automate spasm identification and classification.

The impact of spinal cord injury on breathing during sleep

The prevalence of sleep disordered breathing (SDB) following spinal cord injury (SCI) is considerably greater than in the general population. While the literature on this topic is still relatively small, and in some cases contradictory, a few general conclusions can be drawn. First, while both central and obstructive sleep apnea (OSA) has been reported after SCI, OSA appears to be more common. Second, SDB after SCI likely reflects a complex interplay between multiple factors including body mass, lung volume, autonomic function, sleep position, and respiratory neuroplasticity. It is not yet possible to pinpoint a "primary factor" which will predispose an individual with SCI to SDB, and the underlying mechanisms may change during progression from acute to chronic injury. Given the prevalence and potential health implications of SDB in the SCI population, we suggest that additional studies aimed at defining the underlying mechanisms are warranted.

Dysfunctional sleep in persons with spinal cord injuries and disorders

STUDY DESIGN

Cross-sectional survey of veterans with spinal cord injuries and disorders (SCI/D).

OBJECTIVES

To describe sleep dysfunction (independent of sleep apnea) in persons with traumatic and non-traumatic SCI/D, and to examine characteristics and health outcomes independently associated with sleep dysfunction unrelated to sleep apnea.

SETTING

Seven Veterans Affairs SCI care facilities in the United States.

METHODS

Mailed cross-sectional survey with follow-up calls completed by end of 2008. Bivariate analyses to compare measures outcomes in persons with SCI/D who were dysfunctional sleepers vs those who were not. Multivariate logistic regression used to identify variables independently associated with dysfunctional sleep in veterans with SCI/D.

RESULTS

Overall, 49% of the sample had sleep dysfunction unrelated to sleep apnea. In this subgroup, bivariate analyses showed that a greater proportion of dysfunctional sleepers than non-dysfunctional sleepers were current smokers, had problems with drinking alcohol, hypertension, asthma, chronic obstructive pulmonary disease (COPD) and problematic weight gain. Variables independently associated with higher odds of dysfunctional sleep included white race, being a current smoker, problems with drinking alcohol, asthma, COPD and problematic weight gain.

CONCLUSION

Consistent with epidemiological evidence for the general population, we found significant associations of sleep dysfunction with weight gain, smoking, alcohol misuse and select chronic conditions (COPD, asthma). Sustained sleep dysfunction may contribute to health deterioration and mortality, highlighting the need to address the high prevalence of sleep dysfunction (independent of sleep apnea) in persons with SCI/D. In particular, efforts aimed at modifying problematic weight gain, alcohol misuse and smoking are warranted in this cohort to improve sleep.

International spinal cord injury pulmonary function basic data set

OBJECTIVES

To develop the International Spinal Cord Injury (SCI) Pulmonary Function Basic Data Set within the framework of the International SCI Data Sets in order to facilitate consistent collection and reporting of basic bronchopulmonary findings in the SCI population.

SETTING

International.

METHODS

The SCI Pulmonary Function Data Set was developed by an international working group. The initial data set document was revised on the basis of suggestions from members of the Executive Committee of the International SCI Standards and Data Sets, the International Spinal Cord Society (ISCoS) Executive and Scientific Committees, American Spinal Injury Association (ASIA) Board, other interested organizations and societies and individual reviewers. In addition, the data set was posted for 2 months on ISCoS and ASIA websites for comments.

RESULTS

The final International SCI Pulmonary Function Data Set contains questions on the pulmonary conditions diagnosed before spinal cord lesion,if available, to be obtained only once; smoking history; pulmonary complications and conditions after the spinal cord lesion, which may be collected at any time. These data include information on pneumonia, asthma, chronic obstructive pulmonary disease and sleep apnea. Current utilization of ventilator assistance including mechanical ventilation, diaphragmatic pacing, phrenic nerve stimulation and Bi-level positive airway pressure can be reported, as well as results from pulmonary function testing includes: forced vital capacity, forced expiratory volume in one second and peak expiratory flow. The complete instructions for data collection and the data sheet itself are freely available on the website of ISCoS (http://www.iscos.org.uk).