What's new in sleep medicine

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

Position statement on obstructive sleep apnea in the transportation industry (October 2022)

The American Academy of Sleep Medicine (AASM) has published a position statement on recognizing and treating obstructive sleep apnea (OSA) in commercial drivers and other individuals in safety-sensitive transportation occupations [1,2]. The documents outline roles for key stakeholders, including legislators, employers, law enforcement, payers, health care professionals, and vehicle operators. The AASM recommends that commercial drivers be referred to a sleep medicine specialist for clinical sleep evaluation and diagnostic testing in the presence of a body mass index (BMI) ≥40 kg/m², fatigue or sleepiness while on duty, involvement in a sleepiness-related crash or accident, or a BMI ≥33 kg/m² plus either type 2 diabetes or hypertension requiring two or more medications. (See "Drowsy driving: Risks, evaluation, and management", section on 'Special considerations in commercial drivers'.)

INSOMNIA

Risk of drug overdose in young people prescribed benzodiazepines for sleep disorders (December 2022)

Prescription database studies indicate that benzodiazepines are commonly prescribed for insomnia, despite risks and the availability of safer options. In a recent cohort study in the United States that included over 90,000 children and young adults (age 10 to 29 years) with a sleep disorder who were prescribed a new insomnia medication, benzodiazepines were associated with increased risk of drug overdose in the next six months compared with alternative insomnia medications (trazodone, hydroxyzine, zolpidem, zaleplon, eszopiclone) [3]. Risk was highest among individuals who had also received an opioid prescription in the preceding three months. We do not prescribe benzodiazepines for insomnia in patients taking opioids or in those with a substance use disorder. (See "Pharmacotherapy for insomnia in adults", section on 'Shared warnings and precautions'.)

PARASOMNIAS AND SLEEP-RELATED MOVEMENT DISORDERS

New guideline on rapid eye movement (REM) sleep behavior disorder (January 2023)

A new clinical practice guideline on management of rapid eye movement (REM) sleep behavior disorder (RBD) is available from the American Academy of Sleep Medicine [4,5]. The guideline reviews supporting evidence for pharmacologic treatment in patients with isolated RBD as well as RBD secondary to clinically established Parkinson disease (PD) and related disorders. Evidence-based therapies include melatonin and clonazepam in all subgroups and acetylcholinesterase inhibitors in patients with mild cognitive impairment or PD. We prefer melatonin over clonazepam as first-line therapy in most patients based on improved tolerability, especially in older adults with neurodegenerative disorders (algorithm 1). (See "Rapid eye movement sleep behavior disorder", section on 'Management'.)

Incidence of isolated sleep paralysis in the general population (September 2022)

Episodes of sleep paralysis, in which individuals awaken during rapid eye movement (REM) sleep and are temporarily unable to move or call out, are a classic feature of narcolepsy but can also occur as an isolated phenomenon. The incidence in otherwise healthy adults has not been well defined, however. In a representative sample of the United States population that included >12,000 adults, 10 percent reported having had one or more episodes of sleep paralysis in the past year [6]. Risk factors included sleep deprivation, younger age, posttraumatic stress disorder, chronic pain, and depression. Patients who report sleep paralysis should be queried for other signs of narcolepsy (eg, excessive daytime sleepiness, cataplexy) but in their absence, reassured about the benign nature of these events. (See "Approach to abnormal movements and behaviors during sleep", section on 'During REM sleep'.)

PEDIATRIC SLEEP MEDICINE

Time course of weight gain after adenotonsillectomy for OSA in children (January 2023)

Previous studies have shown a complex relationship between obstructive sleep apnea (OSA), adenotonsillectomy, and weight gain in children. In a randomized trial of early versus delayed adenotonsillectomy in 190 children ages three to five years with mild to moderate OSA, weight gain occurred in the first 12 months after surgery in both groups, but the early intervention group had no further increase in the second postoperative year [7]. These results suggest that postoperative weight gain is time limited and may not represent a new trajectory toward increased risk for obesity. Providers should be aware that children with OSA are at risk for weight gain, regardless of whether they receive adenotonsillectomy, and take steps to minimize or reverse this tendency where possible. (See "Adenotonsillectomy for obstructive sleep apnea in children", section on 'Weight gain'.)

ZSCAN1 autoantibodies in patients with ROHHAD syndrome (September 2022)

ROHHAD (Rapid-onset Obesity, Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation) is a rare syndrome of unknown etiology affecting young children; in approximately one-half of reported cases, patients are found to have peripheral neuroblastic tumors, suggesting a possible paraneoplastic mechanism. In a new study, novel zinc finger and SCAN domain-containing protein 1 (ZSCAN1) autoantibodies were identified in cerebrospinal fluid and/or serum in 7 out of 9 patients with ROHHAD and 0 out of 125 controls [8]. Additional studies confirmed ZSCAN1 expression in tumors of affected patients as well as in hypothalamic tissue lysates from healthy human brain. Further studies are needed to validate these findings; a few case reports have described some success with immunosuppressive therapy, particularly rituximab and cyclophosphamide. (See "Congenital central hypoventilation syndrome and other causes of sleep-related hypoventilation in children", section on 'Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD)'.)