Journal of Sleep Disorders: Treatment and CareISSN: 2325-9639

All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

Research Article, J Sleep Disor Treat Care Vol: 4 Issue: 2

Sleep Disturbance, Psychiatric, and Cognitive Functioning in Veterans with Mild to Moderate Traumatic Brain Injury

Henry J Orff1,2*, Amy J Jak1,2,3, Amber M Gregory4, Candice C Colón5, Dawn M Schiehser2,3,5, Sean PA Drummond1,2,3, James B Lohr1,2, Elizabeth W Twamley1,2
1Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, USA
2Department of Psychiatry, University of California, San Diego, CA, USA
3Psychology Service, VA San Diego Healthcare System, San Diego, CA, USA
4University of Alabama, Birmingham, Department of Psychology, San Diego, CA, USA
5Research Service, VA San Diego Healthcare System, San Diego, CA, USA
Corresponding author : Henry J Orff, PhD
VA San Diego Healthcare System, 3350 La Jolla Village Dr. (9151B), San Diego, CA 92161 USA
Tel: (858) 642-6492; Fax: (858) 642-6340
E-mail: [email protected]
Received: October 06, 2014 Accepted: March 17, 2015 Published: March 19, 2015
Citation: Orff HJ, Jak AJ, Gregory AM, Colón CC, Schiehser DM, et al. (2015) Sleep Disturbance, Psychiatric, and Cognitive Functioning in Veterans with Mild to Moderate Traumatic Brain Injury. J Sleep Disor: Treat Care 4:2. doi:10.4172/2325-9639.1000153

 

Abstract

Sleep Disturbance, Psychiatric, and Cognitive Functioning in Veterans with Mild to Moderate Traumatic Brain Injury

Objective: For many Veterans, traumatic brain injury (TBI) can result in persistent post-concussive symptoms, of which sleep disturbances are among the most common. S disturbances have been shown to increase risk and/or exacerbate psychiatric and physical health problems in many different populations. However, few studies have examined the relationships among sleep, psychiatric, and cognitive functioning in Veterans with TBI.

Methods: Retrospective chart reviews of 137 Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans with a history of mild to moderate TBI referred for cognitive rehabilitation at the Veteran Affairs San Diego Healthcare System.

Results: 100% of Veterans reported clinically significant sleep disturbance (Pittsburgh Sleep Quality Inventory [PSQI] global scores >5). Veterans also reported clinically relevant impairments in sleep latency (50 minutes), total sleep time (5.5 hours), and sleep efficiency (77%). More severe sleep problems were related to greater endorsement of depressive, post-concussive, and post-traumatic stress disorder (PTSD) symptomatology. Conversely, sleep disturbance showed limited associations with objective neuropsychological assessment. Overall measures of affective functioning were significantly associated with global measures of sleep quality, though such relationships were not observed for quantitative measures of sleep.

Conclusions: Veterans with mild to moderate TBI exhibit very high rates of sleep disturbance. Sleep disturbance is associated with higher levels of comorbid psychiatric symptomatology, particularly affective complaints. The high prevalence of sleep problems in Veterans with a history of TBI underscores a need to develop both a better understanding of etiologic mechanisms relating brain injury and sleep and a better clinical appreciation of the ramifications of sleep disturbance on daily functioning and recovery in individuals who experience TBI.

Keywords: Traumatic Brain Injury; Sleep Disturbance; Depression; PTSD; Post-concussive Symptoms; Neuropsychological Performance

Keywords

Traumatic Brain Injury; Sleep Disturbance; Depression; PTSD; Post-concussive Symptoms; Neuropsychological Performance

List of Abbreviations

AUDIT- C - Alcohol Use Identification Test-Consumption Questions
BDI II - Beck Depression Inventory II
CVLT II - California Verbal Learning Test II
CBT-I - Cognitive Behavioral Therapy for Insomnia
D-KEFS - Delis-Kaplan Executive Function System
DSM-IV-TR - Diagnostic and Statistical Manual of Mental Disorders IV-Text Revision
LOC - Loss of Consciousness
NSI - Neurobehavioral Symptom Inventory
NOS - Not Otherwise Specified
OEF/OIF - Operation Enduring Freedom/Operation Iraqi Freedom
PSQI - Pittsburgh Sleep Quality Inventory
PTA - Post-Traumatic Amnesia
PTSD - Post-Traumatic Stress Disorder
PCL - PTSD Checklist
SE – Sleep Efficiency
SL - Sleep Latency
TOMM - Test of Memory Malingering
TST – Total Sleep Time
TBI - Traumatic Brain Injury
WAIS-IV - Wechsler Adult Intelligence Scale IV
WMS-IV - Wechsler Memory Scale IV

Introduction

Although TBI is common in the general population, there is increased clinical and research interest in TBI due to its high incidence in military personnel involved in recent wars. TBI has been identified as the “signature wound” of the Iraq and Afghanistan Wars, with increased rates of TBI attributed to blast-related injuries emanating from artillery, mortar, rocket shells, mines, bombs, grenades, and improvised explosive devices [1]. Although precise rates of TBI in Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans are difficult to determine, comprehensive surveys such as the RAND Corporation Study [2] have found that about 19% of returning service members report having experienced a TBI while deployed. Additionally, approximately 67% of OEF/OIF Veterans seen in VA Polytrauma settings show evidence of possible persistent postconcussive symptoms secondary to a TBI [3].
Sleep disturbances are frequently reported post-TBI sequelae. Research suggests that 25-70% of people experience sleep problems following a TBI and that these sleep disturbances often exacerbate other symptoms as well as impede the rehabilitation process and the ability to return to work [4]. A recent review reported that approximately 46% of all TBI patients with chronic post-injury symptoms have sleep disorders [5]. In this review, the authors concluded that over 50% of the patients who reported post-injury sleep disorders had symptoms consistent with a diagnosis of insomnia, 23% had sleep apnea, 11% post-traumatic hypersomnia, 7% periodic limb movements during sleep, and 6% narcolepsy. Additionally, in a recently-published meta-analysis, Mathias, et al. [6] found that some form of sleep disturbance was reported in 25-29% of individuals following a TBI and that these patients were 2-4 times more likely than individuals in the general population to experience problems with sleep maintenance, sleep efficiency, nightmares, excessive sleepiness, early awakenings, and sleep walking. When examining the prevalence of sleep disturbance in Veteran patient samples, even higher levels of symptomatology have been observed relative to civilian patient surveys [7]. For example, in a chart review of 200 OEF/OIF Veterans evaluated at a VA Polytrauma outpatient clinic, it was found that sleep disturbance following TBI (endorsed by 93.5% of sample) was even more prevalent than that observed in civilian studies [8]. Research also indicates that mild to moderate TBI is most frequently associated with sleep disturbance, as opposed to more severe TBI [9,10].
One of the most actively debated issues in the TBI literature in recent years is the etiology of post-concussive illness following TBI. Emanating from this research are two related, yet competing, hypotheses. The first suggests that TBI acts as a risk factor for development of psychiatric symptomatology, and that observed chronic post-concussive symptomatology results from presence of psychiatric illness (e.g., depression and post-traumatic stress disorder [PTSD]). This hypothesis is supported by research that has shown that depression (along with PTSD and symptom exaggeration) is strongly associated with reports of post-concussive symptoms [11] and through influential work by Hoge et al. [12], which found that PTSD and depression fully mediate the relationship between mTBI history and most subjective measures of health and psychosocial functioning (except head pain).
Alternatively, several studies have suggested that post-concussive symptoms, such as sleep disturbance, may actually precede and/or exist independently of psychiatric illness following TBI. For example, after controlling for other psychiatric conditions, Vanderploeg et al. [13] found that mild TBI may still be significantly associated with headaches, sleep problems, and memory difficulties for years after the injury. Furthermore, persistent post-concussive symptoms in Veterans with deployment related TBI have been shown to mediate the relationship between TBI and psychopathologies such as depression [14,15]. As well, one recent investigation found sleep disturbance to be an independent and early indicator of risk for depression and/or PTSD [14].
In an attempt to further explore these complex relationships, this investigation examined the sleep disturbance and post-concussive functioning in OEF/OIF Veterans with a history of mild to moderate TBI, who were referred for evaluation and treatment at the Veterans Affairs San Diego Healthcare System TBI Cognitive Rehabilitation Clinic. We sought to describe the sleep characteristics of this sample and hypothesized that:
OEF/OIF Veterans who had sustained a mild to moderate TBI would show high prevalence of self-reported sleep disturbance;
Severity of psychiatric symptoms, post-concussive symptoms, and cognitive impairment, would be associated with severity of sleep disturbance;
In a multivariate context, severity of both post-concussive and psychiatric symptoms would show a strong association with both qualitative and quantitative measures of sleep disturbance.

Methods

Subjects
Archival data from 137 OEF/OIF Veterans with a history of mild to moderate TBI referred for cognitive rehabilitation services at the Veterans Affairs San Diego Healthcare System TBI Cognitive Rehabilitation Clinic between April 2009 and June 2013 were evaluated. Mild TBI was defined as loss of consciousness (LOC)>30 minutes and/or post-traumatic amnesia (PTA)>1 day and moderate TBI was defined as LOC>24 hours and/or PTA>7 days [16]. As Glasgow Coma Scale scores and neuroimaging results were not available for most Veterans, these measures were not used in the evaluation of TBI severity in this study. Veterans who were clinically determined to have invalid neuropsychological test results as measured by performance below standard cutoffs on either of two symptom validity measures (Trial 2 and/or Delayed Recall (percent accuracy) on the Test of Memory Malingering (TOMM) [17] and/or total score on the Forced Choice Recognition portion of the California Verbal Learning Test II (CVLT-II) [18] results were not included in the study.
Retrospective chart reviews of the Veterans’ Polytrauma, neuropsychological, and mental health visits were conducted. Information obtained for this archival investigation was primarily gathered from each Veteran’s neuropsychological assessment report and, when necessary, from notes entered by other providers seen by the Veteran in the context of their medical care at the Veterans Affairs San Diego Healthcare System. Given that patient assessments were not systematized in terms of how and what information was collected, the quality of data and availability of information often varied considerably from patient to patient. Nonetheless, for many Veterans data that included measures of personal demographics, TBI history, measures of sleep and post-concussive functioning, psychiatric history (including diagnoses and self-reported psychiatric symptom severity measures), and comprehensive neuropsychological test data were available and therefore included in this study. Demographic data of interest that was consistently available for the majority of the sample included age, gender, years of formal education, and TBI history (including mechanism of injury, number of TBIs, and length of LOC and PTA). This study was approved by the University of California, San Diego Institutional Review Board and Veterans Affairs San Diego Healthcare System Research and Development Committee.
Measures
Symptom severity measures included self-report assessments of:
Sleep: Pittsburgh Sleep Quality Inventory (PSQI) [19]. The PSQI is a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month interval. Nineteen individual items generate seven "component" scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of scores for these seven components yields one global score.
Post-concussive symptoms: Neurobehavioral Symptom Inventory (NSI) [20]. The NSI is a 22-item assessment commonly used to measure post-concussive symptoms. In addition to total score, the NSI can be evaluated on three component scales: affective, cognitive, and somatic per Caplan, et al. [21].
Depression: Beck Depression Inventory (BDI-II) [22]. the BDI-II is a 21-item depression scale used to measure the severity of depressive symptoms.
Post-traumatic Stress: PTSD Checklist (PCL-S) [23]. The PCL-S assesses PTSD symptoms in relation to an identified traumatic event.
Alcohol abuse: Alcohol Use Identification Test-Consumption Questions (AUDIT-C) [24]. The AUDIT-C is a ten-question screening test developed by the World Health Organization to determine if a person's alcohol consumption may be harmful.
Data were also collected from each Veteran’s comprehensive clinical neuropsychological assessment. Neuropsychological measures examined represented major domains of cognitive functioning including: attention and working memory (Digit Span from the Wechsler Adult Intelligence Scale IV [WAIS-IV]) [25]; verbal fluency (Letter and Category Fluency from the Delis-Kaplan Executive Function System [D-KEFS]) [26]; learning and memory (Trials 1-5 Total and Long Delay Free Recall from the California Verbal Learning Test-II [CVLT-II]) [18] and Logical Memory I and II from the Wechsler Memory Scale IV [WMS-IV]) [27]; visuospatial construction (Block Design from the WAIS-IV) [25]; motor functioning (Grooved Pegboard from the Halstead -Reitan Neuropsychological Battery) [28];executive functioning (Trail Making Test, Number-Letter Switching condition and Color-Word Interference Test, Inhibition and Inhibition/Switching conditions, from the D-KEFS) [26]; and processing speed (Digit Symbol Coding and Symbol Search from the WAIS-IV Processing Speed Index) [25].
Statistical analyses
Standardized, published normative scores corrected for age, gender, and/or education (where applicable) were used for neuropsychological variables, with higher scores indicating better performance. It should be noted that the data available for each patient varied as a result of the clinical assessment and/or referral question. All data were checked for normality prior to conducting analyses; log transformations were needed for self-reported sleep latency (SL) and total sleep time (TST) as well as measures of injury, including number of TBIs, LOC, and PTA.
Descriptive statistics were evaluated for sample demographic information. Frequency analyses were conducted to detail the pattern of responses to items on the PSQI Component Scales. Bivariate correlations were performed to compare PSQI Global Scores and selfreported measures of SL, TST, and sleep efficiency (SE) with measures of psychiatric and neuropsychological functioning. To examine the unique contribution of psychiatric and post-concussive factors on sleep disruption, a forward stepwise multiple regression analysis was performed utilizing BDI total score, NSI total score, and PCL total score as independent variables and PSQI total score as the dependent variable. We next ran the same analyses removing the sleep-related items from the BDI-II (question #16), NSI (question #18), and PCL (question #13) to adjust for potential bias in the results due to redundancy between the sleep items on these measures. Lastly, to fully explore the relationships in the data, other dependent measures of sleep disturbance (self-reported TST and SL, as well as the calculated SE from the PSQI) were examined using the same analytic approach noted above. Bonferroni corrections were employed to adjust for multiple comparisons.

Results

Veterans in this sample had a mean age of 31.7, a mean education level of 13.3 years, and a median of 2 TBIs, with their most severe injuries having a median LOC of 42 seconds and a median length of PTA of 0 minutes. Most (86%) of the TBIs in the sample were classified as mild and 14% were classified as moderate. Clinical diagnoses based on the comprehensive neuropsychological assessment included Cognitive Disorder, Not Otherwise Specified (NOS) (53%), cognitively normal (43%), and other diagnoses (4%, e.g., learning disorder) as defined by Diagnostic and Statistical Manual of Mental Disorders IV-Text Revision (DSM-IV-TR) criteria. The sample had moderate levels of self-reported psychiatric symptomatology, including PTSD symptoms, depressive symptoms, and postconcussive symptoms (Table 1).
Table 1: Demographic, Injury, and Psychiatric Variables in OEF/OIF Veterans with a History of Mild to Moderate TBI.
Self-Reported Sleep Impairment and TBI History. 100% of Veterans in the sample reported clinically significant sleep disturbance (PSQI global score>5), including SL averaging 50 (+/- 44) minutes, TST averaging 5.5 (+/- 1.3) hours, and SE averaging 77% (+/-17%). On the PSQI component scales, 42% of Veterans rated sleep latency problems as ”severe,” and 35% of Veterans rated sleep duration problems as “severe.” However, sleep disturbance was the most commonly reported sleep complaint overall, rated as “moderate” or “severe” in severity by 71% of Veterans (Figure 1).
Figure 1: Frequency of Reported Sleep Complaints by Veterans on the PSQI Component Scales.
Global score on the PSQI was not significantly correlated with LOC, PTA, or number of TBIs (all rs>0.073, all ps>0.410) and there were no significant differences in reported sleep complaints between those with a mild versus moderate TBI (t(135)=0.735, p=0.463). Additionally, sleep complaints did not differ significantly between those Veterans diagnosed as cognitively normal versus those diagnosed with Cognitive Disorder NOS and/or Veterans diagnosed with other cognitive conditions (F(15, 121)=0.661, p= 0.817).
Self-Reported Sleep Impairment and Symptom Severity. As shown in Table 2, poorer sleep as measured by the PSQI global score was significantly correlated with greater levels of post-concussive (NSI), mood (BDI-II), and PTSD (PCL symptomatology, but not alcohol use (AUDIT-C). As expected, depressive symptoms were significantly correlated with longer self-reported sleep latencies, less total sleep times, and poorer sleep efficiencies. Total score on the NSI was found to be significantly correlated with less total sleep times and longer selfreported sleep latencies, while PCL total score was score was only found to be significantly correlated with less total sleep time (Table 2).
Table 2: Association between Self-Reported Sleep Impairment on the PSQI and Psychiatric and Neurobehavioral Symptom Severity (Pearson r values).
Self-Reported Sleep Impairment and Neuropsychological Functioning. Bivariate correlations between the PSQI global score and patient-reported measures of SL, TST, and SE with an array of neuropsychological measures revealed a significant correlation between PSQI global score and performance on Digits Forward and Backward (r=-0.237, p=0.007 and r=-0.204, p=0.020, respectively) and between patient-reported SL and DKEFS Color/Word Inhibition Switching (r=-0.251, p=0.006). However, these results failed to retain significance following statistical corrections for multiple comparisons (p>0.005).
Relationship between psychiatric, post-concussive sleep disturbance measures: As noted above, we observed highly significant correlations between NSI, BDI-II, and PCL scores with PSQI global score and selfreported measures of TST, SL, and SE. In an attempt to more fully explore these relationships, we performed several stepwise multiple regressions. As the NSI instrument is comprised of items addressing multiple areas of post-concussive functioning, we separated the NSI into cognitive, somatic, and affective factors prior to performing the regression analyses. In the first model, we regressed BDI-II total score, NSI cognitive, somatic, and affective scores, and PCL total score on PSQI global score. In this analysis, only BDI-II total score was significantly associated with PSQI global score (F (1,74)=12.78, R2=0.147, B=0.384, p=0.001), with all other measures excluded from the model (all p’s>0.106). In a second model we re-ran the analyses after removing the sleep items from each of the independent measures. Results of these analyses proved similar to those from model 1, as only BDI-II total score was significantly associated with PSQI global score (F (1,72)=10.27, R2=0.125, B=0.353, p=0.002), with all other measures excluded from the model (all p’s>0.141). Lastly, we re-ran model 2 using SL, TST, and SE as the dependent variables. In these analyses, none of the predictor variables iwere found to be significantly associated with any of the dependent measures.

Discussion

This investigation evaluated the prevalence of sleep disturbance and its relationship to psychiatric symptomatology and neuropsychological performance in a large clinically-referred sample of OEF/OIF Veterans with a history of mild to moderate TBI. In this study a high percentage of Veterans with mild to moderate TBI endorsed disrupted sleep at the time of their evaluation. The high prevalence rates of sleep disturbance seen in this study and other published reports provide evidence to suggest that a relationship exists between TBI and sleep disturbance in Veterans. Additionally, in this investigation, sleep disturbance was found to be significantly correlated with psychiatric symptomatology, but not with cognitive performance. Overall, variance in global qualitative measures of sleep (i.e., PSQl global score) showed a significant association with depressive symptoms (as opposed to PTSD symptomatology or other post-concussive symptoms), however these relationships were not observed for quantitatively derived measures of sleep (SL, SE, TST).
Our results demonstrate a significant relationship between sleep disturbance and psychiatric disturbance (particularly depressive symptoms). In fact, the etiology of sleep and psychiatric disturbance post–TBI is currently one of the most actively debated issues in the TBI literature. This debate has led to the development of competing hypotheses. Some suggest that TBI is a risk factor for the development of psychiatric symptomatology, and that observed chronic postconcussive symptomatology results from the presence of psychiatric illness (e.g., depression and PTSD). This hypothesis is supported by research that has shown that depression (along with PTSD) is strongly associated with reports of post-concussive symptoms [11] and through work by Hoge et al. [12], which found that PTSD and depression fully mediate the relationship between TBI history and most subjective measures of health and psychosocial functioning (except headache pain). Alternatively, other studies have suggested that post-concussive symptoms may actually precede and/or exist independently of psychiatric illness following TBI. For example, after controlling for other psychiatric conditions, Vanderploeg and colleagues [13] found that TBI may still be significantly associated with headaches, sleep problems, and memory difficulties for years after the injury. Furthermore, persistent post-concussive symptoms in Veterans with deployment-related TBI have been shown to mediate the relationship between TBI and psychopathologies such as depression [14,15]. As well, one recent investigation found sleep disturbance to be an independent and early indicator of risk for depression and/or PTSD [14].
Based on the literature, it seems reasonable to assume that multiple causal pathways may relate sleep disturbance to other post-concussive symptoms following TBI. For example, 1) TBI may directly cause problems such as sleep and/or mood disturbance, 2) TBI may exacerbate pre-existing sleep and/or mood disturbance, leading to greater post-injury impairment caused by these factors, and/or 3) TBI may cause post-concussive problems such as sleep disturbance, which if left untreated lead to real/perceived functional impairment, which in turn may result in more severe psychiatric morbidity (e.g., depression) in at-risk individuals. Our cross-sectional study cannot determine causal pathways, but the findings do support the concept that sleep and comorbid psychiatric disturbance are important factors that need to be concurrently addressed in this patient population. Furthermore, our findings suggest that the relationship between sleep and psychiatric measures may depend to a large degree on the questions being asked of patients. For example, our results found that if patients were evaluated on global and/or qualitative aspects of their sleep, the influence of psychiatric (i.e., mood) factors was significant. However, contrary to our expectations, when patients were evaluated on specific and/or quantitative measures of sleep (e.g., SL, TST, SE), the effects of psychopathology appeared to be nonsignificant. Hence, asking patients how “well” they slept appeared to differentially produce a response set associated significantly with psychopathology in a way not observed when asking patients how “much” they slept.
Another important aspect of this investigation was an attempt to evaluate whether sleep problems in Veterans in the post-acute period following TBI were associated with objective cognitive performance. In general, our results failed to find evidence that sleep played a significant role in objective neuropsychological performance. Failure to find evidence of a relationship between sleep disturbance cognitive impairment in this study may have resulted from limitations in the measures used to assess patients as part of the clinical evaluation, which, although useful for clinical diagnoses of cognitive functioning, may not be sufficiently challenging to show altered performance due to sleep disturbance. Alternatively, the lack of association between sleep disturbance and cognitive functioning may be consistent with recent findings, as reports demonstrate that some sources of sleep disturbances (i.e., insomnia) are not associated with deficits on objective neuropsychological assessments [29,30].
Despite limitations in the science of TBI and its relationship to sleep and psychiatric and cognitive functioning, ultimately the overarching implications of this report (and other published work) underscore the need for clinical interventions in this patient population. From a clinical perspective, recognition of sleep disturbance as an independent, treatable problem may allow for more rapid intervention with behavioral and/or pharmacological approaches that may reduce patient symptomatology following brain injury. In addition to ameliorating sleep complaints, sleep interventions may also have indirect beneficial effects on many of the other post-concussive psychiatric symptoms, thereby leading to enhanced recovery outcomes. Clinical interventional work with TBI patients may also inform current treatment options (e.g., Cognitive Behavioral Therapy for Insomnia [CBT-I]) within this particular patient population, leading to modifications that might improve treatment effectiveness (e.g., adding CBT-I to other empirically supported interventions as a means of improving treatment outcomes).
In summary, Veterans with a history of mild to moderate TBI in this investigation had high rates of sleep disruption following their brain injuries. Sleep problems appeared to be most strongly associated with mood disturbance, and to a lesser extent, PTSD, post-concussive symptoms, and cognitive functioning. Potential limitations to these findings include use of an archival clinical data set and the select nature of the clinical sample studied in this investigation. Additionally, our participants did not have objective sleep data. Future studies should aim to correct these limitations by utilizing a more diverse population of TBI patients and incorporating multiple objective measures of sleep (e.g., actigraphy, polysomnograhpy, and sleep diaries), psychological and daytime functioning, and quality of life, as these issues appear to be prominent concerns in this population. As well, implementation of longitudinal studies may help better determine the causal relationships between TBI and sleep disturbance in this patient population. As noted in published comments [31,32] there is a growing appreciation of the high prevalence of sleep problems in this population and a clear need for a better understanding of the ramifications of sleep disturbance on daily functioning and recovery as well as the potential benefits of treating sleep disturbance in these individuals. Therefore, future investigations should consider incorporating sleep interventions with concurrent assessment of the effects of treatment on overall functioning.

References

  1. Gondusky JS, Reiter MP (2005) Protecting military convoys in Iraq: an examination of battle injuries sustained by a mechanized battalion during Operation Iraqi Freedom II. Mil Med 170: 546-549.

  2. Tanielian T, Jaycox LH (2008) Invisible Wounds of War: Psychological and Cognitive Injuries, Their Consequences, and Services to Assist Recovery. RAND Corporation, Santa Monica, CA.

  3. Lew HL, Otis JD, Tun C, Kerns RD, Clark ME, et al. (2009) Prevalence of chronic pain, posttraumatic stress disorder, and persistent postconcussive symptoms in OIF/OEF veterans: polytrauma clinical triad. J Rehabil Res Dev46:697-702.

  4. Ouellet MC, Savard J, Morin CM (2004) Insomnia following traumatic brain injury: a review. Neurorehabil Neural Repair 18: 187-198.

  5. Castriotta RJ, Murthy JN (2011) Sleep disorders in patients with traumatic brain injury: a review. CNS Drugs 25: 175-185.

  6. Mathias JL, Alvaro PK (2012) Prevalence of sleep disturbances, disorders, and problems following traumatic brain injury: a meta-analysis. Sleep Med 13: 898-905.

  7. Capaldi VF 2nd, Guerrero ML, Killgore WD (2011) Sleep disruptions among returning combat veterans from Iraq and Afghanistan. Mil Med 176: 879-888.

  8. Lew HL, Pogoda TK, Hsu PT, Cohen S, Amick MM, et al. (2010) Impact of the "polytrauma clinical triad" on sleep disturbance in a department of veterans affairs outpatient rehabilitation setting. Am J Phys Med Rehabil89:437-45.

  9. Mahmood O, Rapport LJ, Hanks RA, Fichtenberg NL (2004) Neuropsychological performance and sleep disturbance following traumatic brain injury. J Head Trauma Rehabil 19: 378-390.

  10. Pillar G, Averbooch E, Katz N, Peled N, Kaufman Y, et al. (2003) Prevalence and risk of sleep disturbances in adolescents after minor head injury. Pediatr Neurol 29: 131-135.

  11. Lange RT, Brickell T, French LM, Ivins B, Bhagwat A, et al. (2013) Risk factors for postconcussion symptom reporting after traumatic brain injury in U.S. military service members. J Neurotrauma 30: 237-246.

  12. Hoge CW, McGurk D, Thomas JL, Cox AL, Engel CC, et al. (2008) Mild traumatic brain injury in U.S. Soldiers returning from Iraq. N Engl J Med 358: 453-463.

  13. Vanderploeg RD, Belanger HG, Curtiss G (2009) Mild traumatic brain injury and posttraumatic stress disorder and their associations with health symptoms. Arch Phys Med Rehabil 90: 1084-1093.

  14. Macera CA, Aralis HJ, Rauh MJ, MacGregor AJ (2013) Do sleep problems mediate the relationship between traumatic brain injury and development of mental health symptoms after deployment? Sleep 36: 83-90.

  15. Morissette SB, Woodward M, Kimbrel NA, Meyer EC, Kruse MI, et al. (2011) Deployment-related TBI, persistent postconcussive symptoms, PTSD, and depression in OEF/OIF veterans. Rehabil Psychol 56: 340-350.

  16. Cifu D, Hurley R, Peterson M, Cornis-Pop M, Rikli PA, et al. (2009) VA/DoD clinical practice guideline for management of concussion/mild traumatic brain injury. J Rehabil Res Dev 46:703-16.

  17. Tombaugh TN (1996) Test of Memory Malingering (TOMM). Pearson Education, Inc., San Antonio, TX.

  18. Delis DC, Kramer JH, Kaplan E, Ober BA (2000) California Verbal Learning Test – Second Edition (CVLT –II). Pearson Education, Inc; San Antonio, TX.

  19. Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ (1989) The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res 28: 193-213.

  20. Cicerone KD, Kalmar K (1995) Persistent postconcussion syndrome: The structure of subjective complaints after mild traumatic brain injury. J Head Trauma Rehabil 10:1-17.

  21. Caplan L, Ivins B, Poole J, Vanderploeg R, Jaffee M, et al. (2010) The Structure of Postconcussive Symptoms in 3 US Military Samples. J Head Trauma Rehabil 25:447-458.

  22. Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J (1961) An inventory for measuring depression. Arch Gen Psychiatry 4: 561-571.

  23. Weathers FW, Litz BT, Herman DS, Huska JA, Keane TM (1993) The PTSD checklist: reliability, validity, and diagnostic utility. Ninth Annual Meeting of the International Society for Traumatic Stress Studies, San Antonio.

  24. Bush K, Kivlahan DR, McDonell MB, Fihn SD, Bradley KA (1998) The AUDIT alcohol consumption questions (AUDIT-C): an effective brief screening test for problem drinking. Ambulatory Care Quality Improvement Project (ACQUIP). Alcohol Use Disorders Identification Test. Arch Intern Med 158:1789-1795.

  25. Wechsler D (2008) Wechsler Adult Intelligence Scale-Fourth Edition (WAIS–IV).Pearson Education, Inc., San Antonio, TX.

  26. Delis DC, Kaplan E, Kramer JH (2001) Delis–Kaplan Executive Function System (D–KEFS). Pearson Education, Inc., San Antonio, TX.

  27. Wechsler D (2009) Wechsler Memory Scale – Fourth Edition (WMS-IV).Pearson Education, Inc., San Antonio, TX.

  28. Reitan RM, Wolfson D (1993) The Halstead-Reitan Neuropsychological Test Battery: Theory and clinical interpretation (2edtn) Neuropsychology Press, Tucson, AZ.

  29. Shekleton JA, Rogers NL, Rajaratnam SM (2010) Searching for the daytime impairments of primary insomnia. Sleep Med Rev 14: 47-60.

  30. Orff HJ1, Drummond SP, Nowakowski S, Perils ML (2007) Discrepancy between subjective symptomatology and objective neuropsychological performance in insomnia. Sleep 30: 1205-1211.

  31. Watson NF (2008) Need for More Traumatic Brain Injury Research. Response to Agrawal A. et al. Traumatic Brain Injury and Sleep Disturbances. J Clin Sleep Med 4:87-88.

  32. Castriotta RJ (2008) Collaboration in Research Involving Traumatic Brain Injury and Sleep Disorders. Response to Agrawal A. et al. Traumatic brain injury and sleep disturbances. J Clin Sleep Med 4:178.

Track Your Manuscript

Recommended Conferences

8th International Conference on Epilepsy & Treatment

Amsterdam, Netherlands