Actigraphy for assessment of sleep in traumatic brain injury: Case series, review of the literature and proposed criteria for use

Actigraphic and nursing sleep log measures in moderate-to-severe traumatic brain injury: Identifying discrepancies in total sleep time

BACKGROUND

Sleep disturbances are common in patients with traumatic brain injury (TBI). In an inpatient rehabilitation setting, clinicians often use information from sleep logs filled out by trained nurses to identify and treat sleep disturbances. However, there are limited data related to accuracy of sleep logs, and patient-reported sleep diaries are poor predictors of total sleep time, which raises concern about the accuracy of sleep logs filled out by a third party.

OBJECTIVE

To examine the reliability of sleep logs for participants with TBI by comparing total sleep time determined by sleep logs versus actigraphy.

DESIGN

Prospective, cross-sectional study.

SETTING

Free-standing, academic inpatient rehabilitation facility.

PARTICIPANTS

Thirty individuals (n = 30) participated in the study. Inclusion criteria were (1) diagnosis of moderate-to-severe TBI; (2) age ≥ 18 years at the time of TBI; and (3) participating in inpatient rehabilitation with no prior inpatient rehabilitation admissions.

INTERVENTIONS

Actigraph monitoring using ActiGraph GT9X Link devices was initiated within 72 hours of admission and continued for 7 consecutive days. Sleep logs were concurrently filled out by trained nurses.

MAIN OUTCOME MEASURES

Sleep parameter correspondence between actigraphy and sleep logs in moderate-to-severe TBI.

RESULTS

Only 51.4% of participants' sleep logs and actigraph total sleep time measurements were within 1 hour of each other, and only 23.8% were within 30 minutes. On average, sleep logs overestimated actigraphy-determined total sleep time by 60 minutes compared to actigraphic measurement.

CONCLUSIONS

For those with moderate-to-severe TBI undergoing inpatient rehabilitation, sleep logs are poor predictors of sleep time because they overestimate total sleep time compared to actigraphy. Therefore, clinicians should use caution when using sleep log data to make decisions regarding treatment for sleep disturbances in TBI.

Effects of intravascular photobiomodulation on cognitive impairment and crossed cerebellar diaschisis in patients with traumatic brain injury: a longitudinal study

The association between intravascular photobiomodulation (iPBM) and crossed cerebellar diaschisis (CCD) and cognitive dysfunction in patients with traumatic brain injury (TBI) remains unknown. We postulate that iPBM might enable greater neurologic improvements. The objective of this study was to evaluate the clinical impact of iPBM on the prognosis of patients with TBI. In this longitudinal study, patients who were diagnosed with TBI were recruited. CCD was identified from brain perfusion images when the uptake difference of both cerebella was > 20%. Thus, two groups were identified: CCD( +) and CCD( -). All patients received general traditional physical therapy and three courses of iPBM (helium-neon laser illuminator, 632.8 nm). Treatment assemblies were conducted on weekdays for 2 consecutive weeks as a solitary treatment course. Three courses of iPBM were performed over 2-3 months, with 1-3 weeks of rest between each course. The outcomes were measured using the Rancho Los Amigos Levels of Cognitive Functioning (LCF) tool. The chi-square test was used to compare categorical variables. Generalized estimating equations were used to verify the associations of various effects between the two groups. p < 0.05 indicated a statistically significant difference. Thirty patients were included and classified into the CCD( +) and CCD( -) groups (n = 15, each group). Statistics showed that before iPBM, CCD in the CCD( +) group was 2.74 (exp 1.0081) times higher than that of CCD( -) group (p = 0.1632). After iPBM, the CCD was 0.64 (exp-0.4436) times lower in the CCD( +) group than in the CCD( -) group (p < 0.0001). Cognitive assessment revealed that, before iPBM, the CCD( +) group had a non-significantly 0.1030 lower LCF score than that of CCD( -) group (p = 0.1632). Similarly, the CCD( +) group had a non-significantly 0.0013 higher score than that of CCD( -) after iPBM treatment (p = 0.7041), indicating no significant differences between the CCD( +) or CCD( -) following iPBM and general physical therapy. CCD was less likely to appear in iPBM-treated patients. Additionally, iPBM was not associated with LCF score. Administration of iPBM could be applied in TBI patients to reduce the occurrence of CCD. The study failed to show differences in cognitive function after iPBM, which still serves as an alternative non-pharmacological intervention.

A comparison of agreement between actigraphy and polysomnography for assessing sleep during posttraumatic amnesia

STUDY OBJECTIVES

Sleep disturbance often emerges in the early recovery phase following a moderate to severe traumatic brain injury, known as posttraumatic amnesia. Actigraphy is commonly employed to assess sleep, as it is assumed that patients in posttraumatic amnesia (who display confusion, restlessness, and agitation) would better tolerate this measure over gold-standard polysomnography (PSG). This study evaluated the agreement between PSG and actigraphy for determining (sleep/wake time, sleep efficiency, sleep latency, and awakenings) in patients experiencing posttraumatic amnesia. It also compared the epoch-by-epoch sensitivity, specificity, and accuracy between the Actigraph device's 4 wake threshold settings (low, medium, high, and automatic) to PSG.

METHODS

The sample consisted of 24 inpatients recruited from a traumatic brain injury inpatient rehabilitation unit. Ambulatory PSG was recorded overnight at bedside and a Philips Actiwatch was secured to each patient's wrist for the same period.

RESULTS

There were poor correlations between PSG and actigraphy for all parameters (Lin's concordance correlation coefficient = < 0.80). The low threshold displayed the highest correlation with PSG for wake and sleep time, albeit still low. Actigraphy displayed low specificity (ranging from 17.1% to 36.6%). There appears to be a greater disparity between actigraphy and PSG for patients with increased wake time.

CONCLUSIONS

Actigraphy, while convenient, demonstrated poorer performance in determining sleep-wake parameters in patients with significantly disturbed sleep. Ambulatory PSG can provide a clearer understanding of the extent of sleep disturbances in these patients with reduced mobility during early rehabilitation. Study findings can help design future protocols of sleep assessment during posttraumatic amnesia and optimize treatment.

CITATION

Fedele B, McKenzie D, Williams G, Giles R, Olver J. A comparison of agreement between actigraphy and polysomnography for assessing sleep during posttraumatic amnesia. J Clin Sleep Med. 2022;18(11):2605-2616.

Effects of Cognitive Behavioral Therapy on Pain and Sleep in Adults with Traumatic Brain Injury: A Systematic Review and Meta-Analysis

The objective of this study was to systematically review the literature on the effects of cognitive behavioral therapy (CBT) on insomnia and pain in patients with traumatic brain injury (TBI). PubMed, Embase, the Cochrane Library, Cumulative Index to Nursing and Allied Health, and Web of Science databases were searched. Outcomes, including pain, sleep quality, and adverse events, were investigated. Differences were expressed using mean differences (MDs) with 95% confidence intervals (CIs). The statistical analysis was performed using STATA 16.0. Twelve trials with 476 TBI patients were included. The included studies did not indicate a positive effect of CBT on pain. Significant improvements were shown for self-reported sleep quality, reported with the Pittsburgh Self-Reported Sleep Quality Index (MD, -2.30; 95% CI, -3.45 to -1.15; P < 0.001) and Insomnia Severity Index (MD, -5.12; 95% CI, -9.69 to -0.55; P = 0.028). No major adverse events related to CBT were reported. The underpowered evidence suggested that CBT is effective in the management of sleep quality and pain in TBI adults. Future studies with larger samples are recommended to determine significance. This trial is registered with PROSPERO registration number CRD42019147266.

Evaluation of rest-activity cycles in patients with severe acquired brain injury: an observational study

BACKGROUND

There is little knowledge about rest-activity cycles (RAC) in patients with severe-acquired brain injury (sABI) during early in-hospital rehabilitation. This study aimed to investigate if patients with sABI displayed unconsolidated RACs at the beginning of in-hospital rehabilitation, and how these changed over time.

METHODS

This study was a prospective observational study. All patients consecutively admitted to one ward were screened for eligibility. We recorded accelerometric activity for 20 days. The Daytime Activity Ratio (DAR) of activity between daytime (7-22) and the total activity during the entire day was calculated and used to estimate consolidation.

RESULTS

Fifty-five patients were screened and 20 patients were included. Complete day 1 & 2 data was obtained on 18 patients. Fifty-six percentage of these had a consolidated RAC at the beginning of rehabilitation. On day 19 & 20, complete data could be obtained from 15 patients, 80% of these had consolidation of RAC. When comparing these a significant mean increase of 5.8% 95%CI(0.52; 11.01) in DAR was found p < .05, and the model of all data also showed a significant increase in median DAR over time p < .01.

CONCLUSION

RAC consolidation improves over time in patients admitted for in-hospital early neurorehabilitation.

Effectiveness of Hand Self-Shiatsu to Promote Sleep in Young People with Chronic Pain: a Case Series Design

BACKGROUND

Sleep problems exist for up to 30% of young people, and increase in the case of those with chronic pain. Because exclusive pharmacological management of sleep problems for children with pain is contraindicated, the development of appropriate non-pharmacological sleep interventions is a significant, largely unmet, need.

PURPOSE

This study examined whether the application of a standardized hand self-shiatsu (HSS) intervention within a population of young people with chronic pain would be associated with improved objectively and subjectively measured sleep.

SETTING

The Pain Management Clinic of the Stollery Children's Hospital Hospital, a large tertiary care centre in Edmonton, Alberta and the University of Alberta.

RESEARCH DESIGN

Sixteen young adults, aged 17 to 27, were recruited for a case series study. The intervention involved participants self-applying a standardized hand shiatsu protocol. Participants wore an actigraph for one week at baseline before learning the HSS technique, and then at four- and eight-week follow-up. At the same measurement points they completed validated self-report measures of their sleep quality and daytime fatigue. Each participant also completed a sleep log to supplement the actigraphy data and to collect their general impressions of the HSS experience. Data were analyzed with SPSS 23 software, using Freidman's test for analysis of variance.

RESULTS

The objective data did not support the hypothesis that this standardized HSS protocol improves objectively measured sleep. However, standardized self-report measures demonstrated statistically significant improvement in perceived sleep disturbance (chi-squared test [χ²] = 8.034, p = .02), sleep-related impairment (χ² = 7.614, p = .02), and daytime fatigue as measured by the PROMIS Fatigue SF 8-a (χ² = 12.035, p = .002), and the Flinder's Fatigue Scale (χ² = 11.93, p = .003). Qualitative sleep log information indicated wide-spread endorsement of HSS for the management of sleep difficulties.

CONCLUSION

Contrary to objective findings, self-report data support the technique of HSS to improve sleep. Participants' comments reflected an overall high level of acceptance and appreciation for the HSS technique. Results highlight the importance of expanding the theory and practice related to sleep measurement to better integrate the qualitative domain.

Hospital Environmental Effects on Sleep in Adults With Traumatic Brain Injury in Rehabilitation

PURPOSE

The aim of this study was to describe sleep patterns of adults with traumatic brain injury and examine effects of environmental stressors (patient care activities and light) on patterns of sleep.

DESIGN

A descriptive, correlational, explanatory design was used for this study.

METHODS

Sixty-three subjects with traumatic brain injury (>18 years) on an acute traumatic brain injury rehabilitation unit wore an Actiwatch for 48 hours to collect light and sleep data. Patient care activity data were collected between 11 p.m. and 7 a.m.

FINDINGS

Patient care activities and light occurred between 11 p.m. and 7 a.m. Nighttime sleep duration and sleep efficiency were explained by patient care activities, whereas light explained wake time after sleep onset.

CONCLUSION

Patient care activities and light serve as environmental stressors that affect sleep.

CLINICAL RELEVANCE

Results necessitate examining the need and timing of nursing care activities and light during nighttime. Findings provide a basis for policy changes that optimize sleep.

Practice parameters for the use of actigraphy in the military operational context: the Walter Reed Army Institute of Research Operational Research Kit-Actigraphy (WORK-A)

BACKGROUND

The Walter Reed Army Institute of Research (WRAIR) Operational Research Kit-Actigraphy (WORK-A) is a set of unique practice parameters and actigraphy-derived measures for the analysis of operational military sleep patterns. The WORK-A draws on best practices from the literature and comprises 15 additional descriptive variables. Here, we demonstrate the WORK-A with a sample of United States Army Reserve Officers' Training Corps (ROTC) cadets (n = 286) during a month-long capstone pre-commissioning training exercise.

METHODS

The sleep of ROTC cadets (n = 286) was measured by Philips Actiwatch devices during the 31-day training exercise. The preliminary effectiveness of the WORK-A was tested by comparing differences in sleep measures collected by Actiwatches as calculated by Philips Actiware software against WORK-A-determined sleep measures and self-report sleep collected from a subset of ROTC cadets (n = 140).

RESULTS

Actiware sleep summary statistics were significantly different from WORK-A measures and self-report sleep (all P ≤ 0.001). Bedtimes and waketimes as determined by WORK-A major sleep intervals showed the best agreement with self-report bedtime (22:21 ± 1:30 vs. 22:13 ± 0:40, P = 0.21) and waketime (04:30 ± 2:17 vs. 04:31 ± 0:47, P = 0.68). Though still significantly different, the discrepancy was smaller between the WORK-A measure of time in bed (TIB) for major sleep intervals (352 ± 29 min) and self-report nightly sleep duration (337 ± 57 min, P = 0.006) than that between the WORK-A major TIB and Actiware TIB (177 ± 42, P ≤ 0.001).

CONCLUSIONS

Default actigraphy methods are not the most accurate methods for characterizing soldier sleep, but reliable methods for characterizing operational sleep patterns is a necessary first step in developing strategies to improve soldier readiness. The WORK-A addresses this knowledge gap by providing practice parameters and a robust variety of measures with which to profile sleep behavior in service members.

A Multimethod, Case-Controlled Study of Sleep-Wake Disturbances in Adolescents With Spina Bifida

Objective

This study aimed to compare sleep-wake disturbances in adolescents with spina bifida (SB) to typically developing (TD) peers. Exploratory analyses examined sex as moderator of disrupted sleep.

Methods

Adolescents with SB (ages 12-18 years; N = 37) and a demographically matched sample of TD adolescents (N = 37) completed validated sleep questionnaires and underwent 10 days of actigraphy monitoring.

Results

Adolescents with SB evidenced worse sleep quality, shorter sleep duration, greater sleep maintenance difficulties, and higher levels of fatigue compared with their TD peers. Exploratory analyses revealed females with SB were particularly vulnerable to developing sleep disturbances.

Conclusions

Adolescents with SB are at risk for nighttime sleep disturbances and daytime fatigue. Additional research will need to identify mechanisms and adverse consequences of poor sleep to develop interventions addressing sleep deficiency. Sex-specific disparities in sleep patterns in pediatric SB is a novel finding that requires assessment of etiological underpinnings to clarify clinical implications.

Sleep, Sleep Disorders, and Circadian Health following Mild Traumatic Brain Injury in Adults: Review and Research Agenda

A rapidly expanding scientific literature supports the frequent co-occurrence of sleep and circadian disturbances following mild traumatic brain injury (mTBI). Although many questions remain unanswered, the preponderance of evidence suggests that sleep and circadian disorders can result from mTBI. Among those with mTBI, sleep disturbances and clinical sleep and circadian disorders contribute to the morbidity and long-term sequelae across domains of functional outcomes and quality of life. Specifically, along with deterioration of neurocognitive performance, insufficient and disturbed sleep can precede, exacerbate, or perpetuate many of the other common sequelae of mTBI, including depression, post-traumatic stress disorder, and chronic pain. Further, sleep and mTBI share neurophysiologic and neuroanatomic mechanisms that likely bear directly on success of rehabilitation following mTBI. For these reasons, focus on disturbed sleep as a modifiable treatment target has high likelihood of improving outcomes in mTBI. Here, we review relevant literature and present a research agenda to 1) advance understanding of the reciprocal relationships between sleep and circadian factors and mTBI sequelae and 2) advance rapidly the development of sleep-related treatments in this population.

A pilot randomized controlled trial of on-line interventions to improve sleep quality in adults after mild or moderate traumatic brain injury

Objective:

To explore feasibility and potential efficacy of on-line interventions for sleep quality following a traumatic brain injury (TBI).

Design:

A two parallel-group, randomized controlled pilot study.

Setting:

Community-based.

Subjects:

In all, 24 participants (mean age: 35.9 ± 11.8 years) who reported experiencing sleep difficulties between 3 and 36 months after a mild or moderate TBI.

Interventions:

Participants were randomized to receive either a cognitive behaviour therapy or an education intervention on-line. Both interventions were self-completed for 20–30 minutes per week over a six-week period.

Main measures:

The Pittsburgh Sleep Quality Index assessed self-reported sleep quality with actigraphy used as an objective measure of sleep quality. The CNS Vital Signs on-line neuropsychological test assessed cognitive functioning and the Rivermead Post-concussion Symptoms and Quality of Life after Brain Injury questionnaires were completed pre and post intervention.

Results:

Both programmes demonstrated feasibility for use post TBI, with 83.3% of participants completing the interventions. The cognitive behaviour therapy group experienced significant reductions ( F = 5.47, p = 0.04) in sleep disturbance (mean individual change = −4.00) in comparison to controls post intervention (mean individual change = −1.50) with a moderate effect size of 1.17. There were no significant group differences on objective sleep quality, cognitive functioning, post-concussion symptoms or quality of life.

Conclusion:

On-line programmes designed to improve sleep are feasible for use for adults following mild-to-moderate TBI. Based on the effect size identified in this pilot study, 128 people (64 per group) would be needed to determine clinical effectiveness.

Actigraphic and Sleep Diary Measures in Veterans With Traumatic Brain Injury: Discrepancy in Selected Sleep Parameters

OBJECTIVE

To examine the discrepancy between sleep diary and actigraphic measures of sleep in Veterans with moderate-severe post-acute traumatic brain injury (TBI) and to explore whether these discrepancies vary according to participant characteristics.

SETTING

VA Medical Center in the Rocky Mountain United States.

PARTICIPANTS

Nineteen males with moderate-severe post-acute TBI and insomnia symptoms as measured by the Insomnia Severity Index.

DESIGN

Descriptive, cross-sectional.

MAIN MEASURES

Sleep diary, wrist actigraphy, Ohio State University TBI-Identification Method, Insomnia Severity Index, and Hospital Anxiety and Depression Scale.

RESULTS

There was poor agreement between actigraphic and sleep diary measurements of (1) total sleep time, (2) wake after sleep onset, and (3) sleep onset latency. On average, actigraphy measured greater duration of all 3 sleep parameters. Discrepancies were not found to be associated with specific TBI characteristics or mood-related symptoms.

CONCLUSION

When measuring sleep-related outcomes among Veterans with moderate-severe post-acute TBI, notable mismatches were found between actigraphic and self-reported sleep diary data. Knowledge regarding measure-related limitations is important for both clinical and research practices among those with moderate-severe post-acute TBI.

Trajectories of Sleep and Its Predictors in the First Year Following Traumatic Brain Injury

OBJECTIVES

To examine how sleep patterns change over the first year following traumatic brain injury (TBI) and to determine whether specific demographic and disease characteristics predict the trajectories of sleep.

DESIGN

Prospective study.

PARTICIPANTS

Fifty-three patients with first-ever mild to severe TBI.

MAIN MEASUREMENTS

Sleep measured by actigraphy for 7 consecutive days in the first, third, sixth, and twelfth months following TBI: Chinese versions of Beck Anxiety Inventory and Beck Depression Inventory-II (CBDI-II) measured at the same time points. Data were analyzed with a linear mixed model.

RESULTS

Sleep efficiency (the ratio of sleep time to the total time spent in bed) showed a significant upward trend during the study period. Scores on the Chinese version of the Beck Anxiety Inventory and the CBDI-II as well as the use of analgesics significantly predicted the slope of change in sleep efficiency over time.

CONCLUSIONS

Poor sleep efficiency is a common symptom in the first year among patients with first-ever TBI. Healthcare providers should consider both mental health and pain issues when dealing with sleep complaints in patients with TBI.

Sleep, Sleep Disorders, and Mild Traumatic Brain Injury. What We Know and What We Need to Know: Findings from a National Working Group

Disturbed sleep is one of the most common complaints following traumatic brain injury (TBI) and worsens morbidity and long-term sequelae. Further, sleep and TBI share neurophysiologic underpinnings with direct relevance to recovery from TBI. As such, disturbed sleep and clinical sleep disorders represent modifiable treatment targets to improve outcomes in TBI. This paper presents key findings from a national working group on sleep and TBI, with a specific focus on the testing and development of sleep-related therapeutic interventions for mild TBI (mTBI). First, mTBI and sleep physiology are briefly reviewed. Next, essential empirical and clinical questions and knowledge gaps are addressed. Finally, actionable recommendations are offered to guide active and efficient collaboration between academic, industry, and governmental stakeholders.

Alterations in Daytime and Nighttime Activity in Piglets after Focal and Diffuse Brain Injury

We have developed and implemented a noninvasive, objective neurofunctional assessment for evaluating the sustained effects of traumatic brain injury (TBI) in piglets with both diffuse and focal injury types. Derived from commercial actigraphy methods in humans, this assessment continuously monitors the day/night activity of piglets using close-fitting jackets equipped with tri-axial accelerometers to monitor movements of the thorax. Acceleration metrics were correlated (N = 7 naïve piglets) with video images to define values associated with a range of activities, from recumbancy (rest) to running. Both focal (N = 8) and diffuse brain injury (N = 9) produced alterations in activity that were significant 4 days post-TBI. Compared to shams (N = 6) who acclimated to the animal facility 4 days after an anesthesia experience by blurring the distinction between day and night activity, post-TBI time-matched animals had larger fractions of inactive periods during the daytime than nighttime, and larger fractions of active time in the night were spent in high activity (e.g., constant walking, intermittent running) than during the day. These persistent disturbances in rest and activity are similar to those observed in human adults and children post-TBI, establishing actigraphy as a translational metric, used in both humans and large animals, for assessment of injury severity, progressions, and intervention.

Sleep in traumatic brain injury

More than one-half million patients are hospitalized annually for traumatic brain injury (TBI). One-quarter demonstrate sleep-disordered breathing, up to 50% experience insomnia, and half have hypersomnia. Sleep disturbances after TBI may result from injury to sleep-regulating brain tissue, nonspecific neurohormonal responses to systemic injury, ICU environmental interference, and medication side effects. A diagnosis of sleep disturbances requires a high index of suspicion and appropriate testing. Treatment starts with a focus on making the ICU environment conducive to normal sleep. Treating sleep-disordered breathing likely has outcome benefits in TBI. The use of sleep promoting sedative-hypnotics and anxiolytics should be judicious.

Actigraphic assessment of sleep disturbances following traumatic brain injury

The current study examined the use of actigraphy in measurement of sleep following traumatic brain injury (TBI). Twenty-one patients with TBI and self-reported sleep and/or fatigue problems and 21 non-injured controls were studied over seven days using actigraphy and sleep diary reports. Although strong associations between diary and actigraphic assessment of sleep duration were observed in both participant groups, agreement between these methods appeared to weaken in patients with TBI. Associations between sleep diary and actigraphic assessments of sleep disturbance, i.e., wake after sleep onset (WASO) and sleep onset latency (SOL) were not apparent in either group, although weaker agreement between methods for WASO was again observed in patients with TBI. Actigraphy may prove useful to supplement self-report measures of sleep following TBI. More work is required to understand the accuracy of these measures in this population.

The effects of sleep on the relationship between brain injury severity and recovery of cognitive function: a prospective study

BACKGROUND

Disturbed sleep pattern is a common symptom after head trauma and its prevalence in acute traumatic brain injury (TBI) is less discussed. Sleep has a profound impact on cognitive function recovery and the mediating effect of disturbed sleep on cognitive function recovery has not been examined after acute TBI.

OBJECTIVES

To identify the prevalence of disturbed sleep in mild, moderate, and severe acute TBI patients, and to determine the mediating effects of sleep on the relationship between brain injury severity and the recovery of cognitive function.

DESIGN

A prospective study design.

SETTING

Neurosurgical wards in a medical center in northern Taiwan.

PARTICIPANTS

Fifty-two acute TBI patients between the ages of 18 and 65 years who had received a diagnosis of TBI for the first time, and were admitted to the neurosurgical ward.

METHOD

The severity of brain injury was initially determined using the Glasgow Coma Scale. Each patient wore an actigraphy instrument on a non-paralytic or non-dominated limb for 7 consecutive days. A 7-day sleep diary was used to facilitate data analysis. Cognitive function was assessed on the first and seventh day after admission based on the Rancho Los Amigos Levels of Cognitive Functioning.

RESULTS

The mild (n=35), moderate (n=7) and severe (n=10) TBI patients exhibited poorer sleep efficiency, and longer total sleep time (TST) and waking time after sleep onset, compared with the normative values for the sleep-related variables (P<.05 for all). The severe and moderate TBI patients had longer daytime TST than the mild TBI patients (P<.001), and the severe TBI patients had longer 24-h TST than the mild TBI patients (P=.001). The relationship between the severity of brain injury and the recovery of cognition function was mediated by daytime TST (t=-2.65, P=.004).

CONCLUSIONS

Poor sleep efficiency, prolonged periods of daytime sleep, and a high prevalence of hypersomnia are common symptoms in acute TBI patients. The duration of daytime sleep mediates the relationship between the severity of brain injury and the recovery of cognition function.

Screening for sleep dysfunction after traumatic brain injury

Numerous studies on the high prevalence of sleep disorders in individuals with traumatic brain injury (TBI) have been conducted in the past few decades. These disorders can accentuate other consequences of TBI, negatively impacting mood, exacerbating pain, heightening irritability, and diminishing cognitive abilities and the potential for recovery. Nevertheless, sleep is not routinely assessed in this population. In our review, we examined the selective screening criteria and the scientific evidence regarding screening for post-TBI sleep disorders to identify gaps in our knowledge that are in need of resolution. We retrieved papers written in the English-language literature before June 2012 pertinent to the discussion on sleep after TBI found through a PubMed search. Within our research, we found that sleep dysfunction is highly burdensome after TBI, treatment interventions for some sleep disorders result in favorable outcomes, sensitive and specific tests to detect sleep disorders are available, and the cost-effectiveness and sustainability of screening have been determined from other populations. The evidence we reviewed supports screening for post-TBI sleep dysfunction. This approach could improve the outcomes and reduce the risks for post-TBI adverse health and nonhealth effects (e.g., secondary injuries). A joint sleep and brain injury collaboration focusing on outcomes is needed to improve our knowledge.

Trajectories of sleep changes during the acute phase of traumatic brain injury: a 7-day actigraphy study

BACKGROUND/PURPOSE

To examine trajectories of change in sleep during the acute phase of traumatic brain injury (TBI), and whether specific demographic and disease characteristics predicted the initial levels of sleep and the trajectories of change in sleep parameters.

METHODS

This was a prospective observational study. Fifty-two patients with first-ever TBI were enrolled. Sleep parameters were measured using actigraphy for 7 consecutive days after admission. Hierarchical linear modeling was used for data analyses in 52 TBI patients and in a subgroup of mild TBI patients (n = 31).

RESULTS

Participants had significant lower sleep efficiency, longer wake time after sleep onset, and longer 24-hour total sleep time (TST) than the normative data (all p < 0.05). Seventy-two percent of participants experienced prolonged 24-hour TST. Both daytime and 24-hour TST showed a significant downward trend across the study period. An initial Glasgow Coma Scale score < 11 significantly predicted the slope of change of daytime TST over time. Without initial loss of consciousness and age < 40 years were independent predictors of the change pattern of 24-hour TST over time. In the mild TBI subgroup, 24-hour TST significantly and gradually declined over time. Gender significantly predicted the trajectory of 24-hour sleep duration.

CONCLUSION

Poor sleep efficiency and longer sleep duration are common symptoms in acute TBI patients. Both head injury severity and age predicted the trajectories of daytime and 24-hour sleep duration during the acute phase of TBI, whereas gender predicted the trajectories of 24-hour sleep duration in the mild TBI subgroup.

Using actigraphy and transcranial magnetic stimulation to assess the relationship between sleep and visuomotor skill learning

PURPOSE

Sleep following training can enhance motor skill memory consolidation while chronic sleep disruption can have the converse effect. The aim of this investigation was to explore the relationship between sleep measured by wrist actigraphy, motor skill consolidation and primary motor cortex excitability in young, healthy individuals.

METHODS

Training was a visuospatial finger-tracking task. Dependent measures included tracking skill performance, cortical excitability, measures of sleep, and level of arousal. Assessments occurred pre-training, post-training and at 12 h and 24 h retention. An activity monitor was worn on the wrist during the nights preceding and following training.

RESULTS

Results indicate that sleep during the night following training was predictive of 1) offline skill consolidation following training (R² = 0.34) and 2) cortical excitability at 24 h follow-up (R² = 0.35) with less time spent awake associated with better skill performance and lower cortical excitability at 24 h follow-up. No difference in measures of sleep was observed between nights of sleep (p > 0.05). Sleep the night before training did not influence skill performance, skill acquisition during training, nor measures of cortical excitability at pre-training assessment.

CONCLUSIONS

These findings suggest a relationship between motor skill development, cortical excitability and sleep following training. These results invite further investigation into the utility of actigraphy as a low-cost, easy-to-administer alternative to polysomnography for short and long-term evaluation of the relationship between sleep, cortical excitability and motor skill learning in healthy and patient populations.