Matthew S. Brock

Trauma associated sleep disorder: A parasomnia induced by trauma

Nightmares and disruptive nocturnal behaviors that develop after traumatic experiences have long been recognized as having different clinical characteristics that overlap with other established parasomnia diagnoses. The inciting experience is typically in the setting of extreme traumatic stress coupled with periods of sleep disruption and/or deprivation. The limited number of laboratory documented cases and symptomatic overlap with rapid eye movement sleep behavior disorder (RBD) and posttraumatic stress disorder (PTSD) have contributed to difficulties in identifying what is a unique parasomnia. Trauma associated sleep disorder (TSD) incorporates the inciting traumatic experience and clinical features of trauma related nightmares and disruptive nocturnal behaviors as a novel parasomnia. The aims of this theoretical review are to 1) summarize the known cases and clinical findings supporting TSD, 2) differentiate TSD from clinical disorders with which it has overlapping features, 3) propose criteria for the diagnosis of TSD, and 4) present a hypothetical neurobiological model for the pathophysiology of TSD. Hyperarousal, as opposed to neurodegenerative changes in RBD, is a component of TSD that likely contributes to overriding atonia during REM sleep and the comorbid diagnosis of insomnia. Lastly, a way forward to further establish TSD as an accepted sleep disorder is proposed.

Nightmares in United States Military Personnel With Sleep Disturbances

STUDY OBJECTIVES Sleep disturbances are common in United States military personnel. Despite their exposure to combat and trauma, little is known about nightmares in this population. The purpose of this study was to describe the prevalence and associated clinical and polysomnographic characteristics of nightmares in United States military personnel with sleep disturbances. METHODS Retrospective review of 500 active duty United States military personnel who underwent a sleep medicine evaluation and polysomnography at our sleep center. The Pittsburgh Sleep Quality Index and the Pittsburgh Sleep Quality Index-Addendum were used to characterize clinically significant nightmares. Subjective and objective sleep attributes were compared between groups. RESULTS At least weekly nightmares were present in 31.2%; yet, only 3.9% reported nightmares as a reason for evaluation. Trauma-related nightmares occurred in 60% of those patients with nightmares. Patients with nightmares had increased sleep onset latency (SOL) and rapid eye movement (REM) sleep latency (mean SOL/REM sleep latency 16.6/145 minutes, P = .02 and P = .01 respectively) compared to those without (mean SOL/REM sleep latency 12.5/126 minutes). The comorbid disorders of depression (P ≤ .01, relative risk [RR] 3.55 [95% CI, 2.52-4.98]), anxiety (P ≤ .01, RR 2.57 [95% CI, 1.93-3.44]), posttraumatic stress disorder (P ≤ .01, RR 5.11 [95% CI, 3.43-7.62]), and insomnia (P ≤ .01, RR 1.59 [95% CI, 1.42-1.79]) were all associated with nightmares. CONCLUSIONS Clinically significant nightmares are highly prevalent in United States military personnel with sleep disturbances. Nightmares are associated with both subjective and objective sleep disturbances and are frequently comorbid with other sleep and mental health disorders. COMMENTARY A commentary on this article appears in this issue on page 303.

Sleep disorders related to deployment in active duty service members and veterans

Active duty service members (ADSM) are a unique population at risk for complex health issues; among the most frequent are sleep disorders. Sleep disturbances are prevalent, debilitating, and persistent in ADSM following combat deployments. Multiple factors associated with deployment and combat operations place ADSM at risk for acute sleep disturbances. If untreated, acute sleep disturbances can become chronic sleep disorders that result in physical and mental impairments and decreased military readiness. Sleep disorders are frequently comorbid with posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI). However, they are independent clinical disorders which require specific therapy. The consequences of sleep disorders are increasingly recognized in both ADSM and veterans and pose an unprecedented challenge to medical providers who care for these populations.

Comorbid insomnia and sleep apnea: a prevalent but overlooked disorder

Dear Editor: Comorbid insomnia and obstructive sleep apnea (OSA) was first described 45 years ago and was well characterized by Krakow and colleagues in 2001 [1–3]. Despite the realization that this comorbidity was under-recognized and had implications for disease-related outcomes, little has changed in the ensuing years [4]. In this issue of Sleep and Breathing, there are three articles in veteran populations which substantially further our understanding of this disorder. Using a modification to the Insomnia Severity Index (ISI), Wallace et al. reported that 47% of US veterans who underwent an initial evaluation for OSA had insomnia. Specifically, they required a score ≥ 6 on the first three questions, which assesses difficulties in falling asleep, staying asleep, or awakening too early and are consistent with moderate insomnia symptoms. Another major finding from their study is that patients with comorbid early and late insomnia symptoms and OSA are less adherent to positive airway pressure (PAP) at 6 months. In the paper by El-Solh et al., the effect of insomnia on US veterans with posttraumatic stress disorder (PTSD) and OSA was assessed. They also used the ISI with the standard threshold score ≥ 15 to classify patients as having insomnia. In this study, veterans with comorbid insomnia were more likely to have depression, decreased quality of life, and worse sleep quality on polysomnography (PSG). Similar to the findings of Wallace et al., the veterans with comorbid insomnia, OSA, and PTSD were significantly less adherent to PAP and also had no improvements in overall sleep quality. In the third paper, Rezaeitalab et al. found that insomnia, diagnosed by clinical interview, was the most frequent symptom in Iranian veterans with PTSD and OSA; this was despite nearly all patients taking medications for insomnia at the time of their evaluation. There are a number of studies which report on the prevalence of comorbid insomnia and OSAwith rates ranging from 13.8% in patients with moderate to severe OSA in a general sleep clinic to as high 90.9% in crime victims with nightmares and PTSD [2, 3, 5, 6]. The wide range in prevalence is in part due to the difference in patient populations, but another reason is the variation in study methodology. Studies assessing this comorbidity have typically taken one of two approaches, evaluating patients with known OSA for insomnia or patients with insomnia for the presence of sleep disordered breathing. The patient populations differ based on which diagnosis was initially studied and thus, which diagnosis is considered comorbid. The overlap of shared symptoms between the two conditions further complicates making the diagnosis. Utilization of different criteria to diagnose sleep apnea [7] as well as differing nocturnal and daytime features to diagnose insomnia, including self-reported symptoms [8] and objective PSG parameters [9], has also contributed to this variability. The high prevalence of comorbid insomnia and OSA and significantly lower PAP adherence in patients with both disorders compared to OSA alone underscore the need for a standardized systematic approach to identifying and treating these sleep disorders when they co-occur. Several barriers to standardization exist. First, the nosology in the literature is inconsistent with terminology including OSA-insomnia [9], complex insomnia [2], and comorbid insomnia and OSA among others. This inconsistency creates confusion and further highlights the variability that exists in diagnosing comorbid insomnia and OSA. The recently used acronym “COMISA” for comorbid insomnia and sleep apnea conveys the presence of both conditions in a memorable and potentially unifying term [10]. Another barrier to recognizing COMISA is the absence of standard diagnostic criteria for this disorder. Wallace et al. This article is part of the Topical Collection on Comorbid Insomnia and OSA (COMISA) in Veterans

An Initial Report of Sleep Disorders in Women in the U.S. Military

Introduction Sleep disorders are increasingly recognized in active duty service members (ADSM). While there are multiple studies in male ADSM, there are limited data regarding sleep disorders in women in the military. The purpose of this study was to characterize sleep disorders in female ADSM referred for clinical evaluation to provide a better understanding of this unique population. Materials and Methods We conducted a retrospective review of female ADSM who underwent a sleep medicine evaluation and an attended polysomnogram (PSG). Demographic and polysomnogram variables, as well as medical records, were reviewed. Associated illnesses to include post-traumatic stress disorder, pain disorders, anxiety, and depression, were recorded. Results The cohort consisted of 101 women. The average age was 33.9 ± 9.0 years and body mass index was 27.3 ± 4.5, with an average Epworth Sleepiness Scale score of 12.9 ± 5.2, and Insomnia Severity Index score of 17.6 ± 5.7. Overall, 36.6% were diagnosed with insomnia only, 14.9% with obstructive sleep apnea (OSA) only, and 34.7% met diagnostic criteria for both insomnia and OSA. The average apnea-hypopnea index for the entire cohort was 5.37 ± 7.04/h whereas it was 10.34 ± 3.14/h for those meeting diagnostic criteria for OSA. The women referred for sleep evaluations had the following rates of associated illnesses: pain disorders (59.4%), anxiety (48.5%), depression (46.5%), and post-traumatic stress disorder (21.8%). For patients with OSA, the relative risk of having post-traumatic stress disorder was 2.72 (95% confidence interval 1.16-6.39). Conclusions Women in the U.S. military who have sleep disorders have a high rate of behavioral medicine and pain disorders. Interestingly, nearly 50% of active duty females referred for a sleep study have OSA while not necessarily manifesting the typical signs of obesity or increased age. The reasons for this finding are not completely understood, though factors related to military service may potentially contribute. The findings from our study indicate a need for increased awareness and evaluation of sleep disorders in women in the military, especially those with behavioral medicine disorders.

Time for a standardized clinical assessment for narcolepsy with obstructive sleep apnea

Dear Editor, The article by Dunne et al. addresses an important topic in sleep medicine, the appropriate evaluation and diagnosis of patients with narcolepsy [1]. While adhering to the American Academy of Sleep Medicine recommendations for the performance of multiple sleep latency testing in their cohort [2], the 19 patients determined to have narcolepsy had an unexpectedly high rate of obstructive sleep apnea (OSA). Overall, 14 of the narcoleptics had OSA, with half of those with OSA having moderate to severe sleep disordered breathing. The apnea hypopnea indexes of these seven patients ranged from 18.5 to 108.7/h. In patients with moderate–severe OSA, the appropriate diagnosis of narcolepsy is a diagnostic challenge. As treatment of the narcoleptic patients with OSA was not reported, this begs the question, how were the excessive daytime somnolence and potential for false-positive multiple sleep latency testing (MSLT) adjudicated? Untreated OSA, especially severe OSA, is an established cause for a false-positive MSLTwith ≥2 sleep onset rapid eye movement periods (SOREMPs) [3]. The likelihood of two or more SOREMPs is independently predicted by several variables including male sex, sleepiness, nocturnal REM sleep latency, and the extent of oxygen desaturation [4]. A possible explanation for increased SOREMPs among patients with sleep disordered breathing may be nocturnal, selective REM sleep deprivation as OSA tends to be most severe in REM [5]. In order to improve diagnostic accuracy of narcolepsy, the American Academy of Sleep Medicine recommends the exclusion of other causes of excessive daytime sleepiness (EDS), to include OSA [6]. To our knowledge, there is no guideline as to how to render the diagnosis of narcolepsy and OSA simultaneously. However, given that EDS and a false-positive MSLT both occur with OSA, especially severe disease, we would suggest that moderate–severe OSA is treated with adequate positive airway pressure adherence prior to rendering a definitive narcolepsy diagnosis. Sleep disordered breathing is frequently present in patients with narcolepsy, yet a rate of 73.7% is greater than what is typically reported. Frauscher et al. in their cohort of 100 patients with narcolepsy had reported 24% of patients had cooccurring OSA, with 42% having moderate–severe OSA [7]. Another study by Sansa et al. from Spain found 24.8% of 133 narcoleptics had an AHI > 10 [8]. In their cohort, narcoleptics without cataplexy who also had comorbid OSAwere required to have either four SOREMPs on a five-nap MSLT or a cerebrospinal fluid hypocretin level <110 pg/ml. While the majority of the patients, 84%, who were confirmed to have narcolepsy had a history of cataplexy, the authors report that 27% of the non-narcoleptics also had a history of cataplexy. The report of cataplexy in the non-narcoleptics suggests either the referring physicians were unable to determine the difference between cataplexy or cataplexy-like symptoms or the patients had to some degree learned this symptom. This highlights the importance of appropriately adjudicating cataplexy, which is frequently subtle and does not typically occur in clinical settings. Witnessed and/or video evidence of All work was performed at Wilford Hall Ambulatory Surgical Center, JBSA Lackland, TX 78236.

Obstructive Sleep Apnea is an Independent Risk Factor for Hospital Readmission

STUDY OBJECTIVES Hospital readmissions are an important metric of quality and safety. This study seeks to characterize the relationship between readmissions and obstructive sleep apnea (OSA). A better understanding of this relationship could be utilized to develop preventative measures and reduce readmission rates. METHODS A retrospective review of patients discharged over a 24-month period to a Department of Defense hospital was conducted. Medical records review provided demographic data, presence of OSA and comorbid diseases, and whether readmission occurred within 30 days of discharge. Statistical analysis assessed risk factors for readmission, and multivariate analysis was performed. Next, 125 readmitted patients with OSA were randomly selected for detailed chart review and compared to a matched cohort that was not readmitted. RESULTS Of 22,261 unique patients discharged, 1,899 (8.5%) were readmitted. Patients with OSA had a readmission rate of 11.4% versus 7.6% for patients without OSA (P < .00001). Multivariable analysis revealed an odds ratio of 1.46 for readmission in patients with OSA (P < .0001). For the detailed chart review of 250 patients, length of hospital stay differed for the readmitted and non-readmitted groups (5.1 versus 3.6 days; P = .007). Apnea-hypopnea index (24.1 versus 27.2 events/h; P = .48) was similar between the groups. Also, inpatient (27.2% versus 26.4%) and outpatient (38.4% versus 37.6%) positive airway pressure (PAP) treatment rates were not different. CONCLUSIONS This study found OSA to be an independent risk factor for readmission within 30 days of discharge. PAP therapy appears to be underutilized in patients with known OSA. Additional studies are needed to define the relationship between OSA, PAP adherence, and hospital readmission.

COMISA (Comorbid Insomnia and Sleep Apnea): a Practical Approach

Purpose of ReviewComorbid insomnia and sleep apnea (COMISA) is prevalent and carries significant morbidity but lacks a standardized diagnostic and therapeutic approach. Through a critical evaluation of the literature, we propose a novel approach to COMISA that incorporates the underlying etiology and existence of different phenotypes in this disorder.Recent FindingsA low arousal threshold and/or hyperarousability may underlie the development of COMISA. Pretreatment symptoms may serve as baseline predictors of response to positive airway pressure therapy in COMISA and differentiate insomnia secondary to OSA from independent insomnia. A variety of therapeutic strategies for COMISA have been put forward with evidence supporting the use of monotherapy or combined therapy in the appropriate clinical setting.SummaryPatients with either OSA or insomnia must be effectively screened for both disorders based on presenting symptoms and response to therapy. Recognition of the underlying etiology of COMISA and the different COMISA phenotypes can guide therapy.