Improvement has been anecdotally observed in patients with persistent postconcussion symptoms (PCS) after mild traumatic brain injury following treatment with hyperbaric oxygen (HBO). The effectiveness of HBO as an adjunctive treatment for PCS is unknown to date. OBJECTIVES To compare the safety of and to estimate the efficacy for symptomatic outcomes from standard PCS care alone, care supplemented with HBO, or a sham procedure. DESIGN, SETTING, AND PARTICIPANTS Multicenter, double-blind, sham-controlled clinical trial of 72 military service members with ongoing symptoms at least 4 months after mild traumatic brain injury enrolled at military hospitals in Colorado, North Carolina, California, and Georgia between April 26, 2011, and August 24, 2012. Assessments occurred before randomization, at the midpoint, and within 1 month after completing the interventions. INTERVENTIONS Routine PCS care was provided in specialized clinics. In addition, participants were randomized 1:1:1 to 40 HBO sessions administered at 1.5 atmospheres absolute (ATA), 40 sham sessions consisting of room air at 1.2 ATA, or no supplemental chamber procedures. MAIN OUTCOMES AND MEASURES The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) served as the primary outcome measure. A change score of at least 2 points on the RPQ-3 subscale (range, 0-12) was defined as clinically significant. Change scores from baseline were calculated for the RPQ-3 and for the total RPQ. Secondary measures included additional patient-reported outcomes and automated neuropsychometric testing. RESULTS On average, participants had sustained 3 lifetime mild traumatic brain injuries; the most recent occurred 23 months before enrollment. No differences were observed between groups for improvement of at least 2 points on the RPQ-3 subscale (25% in the no intervention group, 52% in the HBO group, and 33% in the sham group; P = .24). Compared with the no intervention group (mean change score, 0.5; 95% CI, −4.8 to 5.8; P = .91), both groups undergoing supplemental chamber procedures showed improvement in symptoms on the RPQ (mean change score, 5.4; 95% CI, −0.5 to 11.3; P = .008 in the HBO group and 7.0; 95% CI, 1.0-12.9; P = .02 in the sham group). No difference between the HBO group and the sham group was observed (P = .70). Chamber sessions were well tolerated. CONCLUSIONS AND RELEVANCE Among service members with persistent PCS, HBO showed no benefits over sham compressions. Both intervention groups demonstrated improved outcomes compared with PCS care alone. This finding suggests that the observed improvements were not oxygen mediated but may reflect nonspecific improvements related to placebo effects. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01306968

Study Objectives: The aim was to assess the relationship between continuous positive airway pressure (CPAP) therapy and cognitive function in patients with mild cognitive impairment (MCI) and obstructive sleep apnea (OSA). Methods: This was a retrospective chart review of patients with MCI and OSA. CPAP therapy compliance was defined as average use of CPAP therapy for at least 4 hours per night. Kaplan-Meier estimates, log-rank tests, and Cox proportional hazards regression were done to compare the compliance groups in terms of progression to dementia, defined as a Clinical Dementia Rating of 1 or greater. Linear mixed models were used to assess the relationships between CPAP therapy compliance and neurological cognitive function outcomes over time. Results: Ninety-six patients were included with mean age at MCI diagnosis of 70.4 years, mean apnea-hypopnea index of 25.9 events/h, and mean duration of neurology follow-up of 2.8 years. Forty-two were CPAP compliant, 30 were noncompliant, and 24 had no CPAP use. No overall difference between the groups was detected for progression to dementia (P =.928, log-rank test). Patients with amnestic MCI had better CPAP use (P =.016) and shorter progression time to dementia (P = .042), but this difference was not significant after adjusting for age, education, and race (P = .32). Conclusions: CPAP use in patients with MCI and OSA was not associated with delay in progression to dementia or cognitive decline.

Posterior Reversible Encephalopathy Syndrome (PRES) is a syndrome comprising headache, altered mentation, and seizures, associated with neuroimaging findings characteristic of subcortical edema in the posterior regions. It is usually seen in patients treated with immunosuppressants, in renal failure, or with eclampsia. Recurrent episodes of PRES in the same patient are rarely observed. Although seizures are often seen in PRES, EEG findings are not well described and include generalized and focal slowing with epileptiform discharges; there are limited reports of Periodic Lateralized Epileptiform Discharges (PLEDs) occurring during PRES, and there are no reports of PRES associated with PLEDs with subsequent development of epilepsy. We report a patient we followed for one year with recurrent episodes of PRES associated with posteriorly dominant independent bilateral PLEDs who subsequently developed epilepsy. Patients with PRES and PLEDs should be treated aggressively with anti-hypertensive and anti-epileptic agents in order to avoid potential complications. Although PRES is typically thought of as a reversible syndrome, this case illustrates that PRES may have serious long term sequelae after the reversible syndrome has resolved. This case highlights the importance of aggressive management of PRES as well as the prevention of subsequent episodes of PRES as patients may develop permanent brain dysfunction.

Study Objective: Esophageal manometry (Pes) is the gold standard to detect repetitive episodes of increased respiratory effort followed by arousal (RERAs). Because RERAs are not included in the apnea-hypopnea index (AHI), we often refer patients with symptoms of sleep disordered breathing (SDB) and AHI < 5 for a second polysomnogram (PSG) with Pes. Often, the second PSG will demonstrate AHI > 5, confi rming a diagnosis of OSA. We speculate that in most cases of suspected SDB, Pes does not add further diagnostic data and that night-to-night variability in OSA severity results in a fi rst false-negative study. Methods: We conducted a retrospective review of PSGs between 2008 and 2012 in adults with initial PSG negative for OSA followed by a second study (with or without Pes) within 6 mo. Results: Of 125 studies that met inclusion criteria, a second study was completed with Pes in 105 subjects. SDB was diagnosed in 73 subjects (68.5%) completing a second PSG with Pes: 49 (46.7%) received a diagnosis based on AHI, and 24 (22.8%) received a diagnosis based on Pes (p = 0.003). There were no statistically signifi cant differences in the mean AHI change between the two PSGs in subjects who completed the second study with or without Pes. Conclusions:In patients with symptoms of SDB and initial PSG with AHI < 5, the majority met criteria for OSA on second PSG by AHI without additional information added by Pes. Because Pes is not widely available and is somewhat invasive, a repeat study without Pes may be suffi cient to diagnose SDB. Keywords: obstructive sleep apnea, polysomnography, sleep apnea/hypopnea syndrome, sleep disordered breathing, upper airway resistance sleep apnea syndrome Citation: Skiba V, Goldstein C, Schotland H. Night-to-night variability in sleep disordered breathing and the utility of esophageal pressure monitoring in suspected obstructive sleep apnea.