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The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.
SLEEP-RELATED BREATHING DISORDERS
Risk of cognitive impairment in adults with sleep-disordered breathing (November 2017)
Obstructive sleep apnea (OSA) and other causes of sleep-disordered breathing are increasingly recognized as a risk factor for cognitive impairment and dementia, possibly through deleterious effects of hypoxemia or shared vascular risk factors. In a pooled analysis of prospective studies in over 200,000 adults, those with sleep-disordered breathing were 26 percent more likely to develop clinically relevant cognitive decline or dementia . Further studies are needed to determine whether effective treatment of OSA can reduce the risk of dementia. (See "Risk factors for cognitive decline and dementia", section on 'Obstructive sleep apnea'.)
Unilateral phrenic nerve stimulation device for central sleep apnea (October 2017)
An implantable device that causes diaphragmatic contraction via unilateral transvenous phrenic nerve stimulation has been approved by the US Food and Drug Administration for treatment of moderate to severe central sleep apnea (CSA) . In a randomized trial in which 151 patients with moderate to severe CSA underwent device implantation, those assigned to active stimulation for six months were more likely to achieve 50 percent or greater reduction in the apnea-hypopnea index than those assigned to no stimulation (51 versus 11 percent) . Therapy-related discomfort was reported by over one-third of patients but resolved with device reprogramming in all but one. The one-year device complication rate was approximately 10 percent in both groups. Additional studies on cardiovascular outcomes and long-term safety are needed to determine the role of the device in relation to other less invasive therapies for CSA. (See "Central sleep apnea: Treatment", section on 'Phrenic nerve stimulation'.)
CPAP for patients with OSA does not prevent cardiovascular events or death (September 2017)
A recent meta-analysis of 10 randomized trials of patients with obstructive sleep apnea (OSA) reported that compared with no treatment or sham, therapy with continuous positive airway pressure (CPAP) did not reduce the risk of major cardiovascular events (acute coronary events, stroke, or vascular death) or all-cause death . The lack of benefit was independent of the severity of OSA and the duration of therapy. Despite these results, CPAP should continue to be the mainstay of therapy for OSA with the goal of improving outcomes other than cardiovascular events (eg, symptom relief, avoidance of accidents, blood pressure control). (See "Obstructive sleep apnea and cardiovascular disease in adults", section on 'Impact of treatment'.)
PARASOMNIAS AND SLEEP-RELATED MOVEMENT DISORDERS
Revised diagnostic criteria for dementia with Lewy bodies (July 2017)
Revised consensus criteria for the clinical diagnosis of dementia with Lewy bodies (DLB) have been published . The updated criteria now recognize rapid eye movement (REM) sleep behavior disorder as a core clinical feature of DLB, along with three previously recognized features: cognitive fluctuations, visual hallucinations, and parkinsonism (table 1). In patients with dementia, probable DLB can be diagnosed in the presence of two or more core clinical features or at least one core feature plus an indicative biomarker (reduced dopamine transporter [DAT] uptake in basal ganglia, abnormal 123-iodine-metaiodobenzylguanidine [MIBG] myocardial scintigraphy, or REM sleep without atonia on polysomnography). (See "Clinical features and diagnosis of dementia with Lewy bodies", section on 'Clinical features'.)
PEDIATRIC SLEEP MEDICINE
Complex motor behaviors during REM sleep in children with narcolepsy type 1 (September 2017)
Complex motor behaviors during rapid eye movement (REM) sleep are well described in adults with narcolepsy, but their prevalence in children has not been well documented. In a series of 40 children with narcolepsy type 1 who underwent video polysomnography, nearly one-third of patients exhibited motor behaviors during REM sleep ranging from classic dream enactment (eg, vigorous reaching or throwing movements) to more calm, slow pantomime-like events . Events were more common among children with impaired nighttime sleep, worse daytime sleepiness, and severe cataplexy. (See "Narcolepsy in children", section on 'Other sleep disturbances'.)
GENERAL SLEEP MEDICINE
Insufficient sleep and cardiometabolic risk (November 2017)
Short sleep duration has been associated with a variety of adverse cardiovascular outcomes in cross-sectional and small prospective studies. In the largest prospective study to date of over 160,000 healthy, nonobese adults, self-reported sleep duration <6 hours per day was associated with the development of multiple cardiometabolic risk factors over an 18-year follow-up period, including central obesity, elevated fasting glucose, hypertension, low high-density lipoprotein cholesterol, hypertriglyceridemia, and metabolic syndrome . Increases in relative risk ranged from 6 to 12 percent for each individual factor. Healthy sleep behavior is recommended by the American Heart Association and others to promote optimal cardiac health. (See "Insufficient sleep: Definition, epidemiology, and adverse outcomes", section on 'Cardiovascular morbidity'.)
Sleepiness at the wheel and risk of motor vehicle crashes (November 2017)
Drowsy driving is a common cause of motor vehicle crashes and near-miss accidents. In a meta-analysis of 17 observational studies, self-reported sleepiness while driving was associated with a 2.5-fold increase in the relative risk of motor vehicle crash . Groups at especially high risk of habitual drowsy driving include teenagers, patients with obstructive sleep apnea and other sleep disorders, commercial drivers, and night shift workers. (See "Drowsy driving: Risks, evaluation, and management", section on 'Epidemiology'.)
- Leng Y, McEvoy CT, Allen IE, Yaffe K. Association of Sleep-Disordered Breathing With Cognitive Function and Risk of Cognitive Impairment: A Systematic Review and Meta-analysis. JAMA Neurol 2017; 74:1237.
- Costanzo MR, Ponikowski P, Javaheri S, et al. Transvenous neurostimulation for central sleep apnoea: a randomised controlled trial. Lancet 2016; 388:974.
- Yu J, Zhou Z, McEvoy RD, et al. Association of Positive Airway Pressure With Cardiovascular Events and Death in Adults With Sleep Apnea: A Systematic Review and Meta-analysis. JAMA 2017; 318:156.
- McKeith IG, Boeve BF, Dickson DW, et al. Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium. Neurology 2017; 89:88.
- Antelmi E, Pizza F, Vandi S, et al. The spectrum of REM sleep-related episodes in children with type 1 narcolepsy. Brain 2017; 140:1669.
- Deng HB, Tam T, Zee BC, et al. Short Sleep Duration Increases Metabolic Impact in Healthy Adults: A Population-Based Cohort Study. Sleep 2017; 40.
- Bioulac S, Franchi JM, Arnaud M, et al. Risk of Motor Vehicle Accidents Related to Sleepiness at the Wheel: A Systematic Review and Meta-Analysis. Sleep 2017; 40.