The Psychomotor Vigilance Test as a measure of alertness and sleep inertia in people with central disorders of hypersomnolence.

STUDY OBJECTIVES: The central disorders of hypersomnolence (CDH) manifest with daytime sleepiness, often accompanied by cognitive symptoms. Objective tests characterizing cognitive dysfunction may have diagnostic utility. Further, because some people with CDH report worsening cognition upon awakening, cognitive testing before and after napping may provide additional diagnostic information. METHODS: Patients with CDH with idiopathic hypersomnia (n = 76), narcolepsy type 1 (n = 19), narcolepsy type 2 (n = 22), and self-reported excessive daytime sleepiness not meeting current diagnostic criteria (n = 76) and nonsleepy controls (n = 33) underwent testing with the Psychomotor Vigilance Test (PVT), a 10-minute reaction-time test. A subset of participants underwent repeat testing during a Multiple Sleep Latency Test, before and immediately after naps 2 and 4. RESULTS: Most PVT metrics were significantly better in controls than in patients with CDH. Minimal group differences in PVT performance were observed by CDH diagnosis. PVT performance was weakly correlated to Epworth Sleepiness Scale and Multiple Sleep Latency Test mean sleep latency in the CDH group. Before and after naps, PVT metrics were minimally different for controls, while PVT performance generally worsened following naps in the CDH group, with significant worsening compared with controls for nap 2 mean, median, lapses, and fastest 10% of responses and nap 4 lapses and slowest 10% of responses. Change in performance did not differ based on CDH diagnostic group for any metric on either nap. CONCLUSIONS: The PVT, at baseline and following a short nap, may provide adjunctive diagnostic utility in separating individuals with CDH from controls. CITATION: Trotti LM, Saini P, Bremer E, et al. The Psychomotor Vigilance Test as a measure of alertness and sleep inertia in people with central disorders of hypersomnolence. J Clin Sleep Med. 2022;18(5):1395-1403.

Circadian Phase and Phase Angle Disorders in Primary Insomnia.

Objectives: We aimed to identify the prevalence of circadian phase and phase angle abnormalities in patients with insomnia. Methods: We conducted a cross-sectional, multicenter study at three sleep laboratories in the United States and Australia. Patients with insomnia and healthy control participants completed a sleep log for 7 days. Circadian phase was assessed from salivary dim light melatonin onset (DLMO) time during a 12-hour laboratory visit. Results: Seventy-nine patients meeting the Research Diagnostic Criteria for Primary, Psychophysiological, Paradoxical, and/or Idiopathic Childhood Insomnia (46 females, 35.5 ± 12.3 years [M ± SD]) and 21 controls (14 females, 34.4 ± 11.8 years). As compared to controls, patients with insomnia tried to initiate sleep on average at the same clock time (24:17 ± 1:17 hours vs. 24:13 ± 1:30 hours, respectively; p = .84) but had a later average DLMO times (20:56 ± 1:55 hours, 18:17-01:21 vs. 22:02 ± 2:02 hours, 17:11-04:52, respectively; p = .04). Consequently, patients with insomnia slept at an earlier circadian phase than controls (phase angle, bedtime-DLMO 2:13 hours (± 1:43) vs. 3:10 hours (± 1:08), respectively; p = .008), of whom 10% tried to sleep at or before DLMO (compared to 0 controls), and 22% tried to sleep before or within 1 hour after DLMO (compared to 6% of controls). Conclusions: A substantial proportion (10%-22%) of patients with insomnia initiate sleep at too early a circadian phase, implicating a circadian etiology for their insomnia. Outpatient circadian phase assessments should be considered to improve differential diagnoses in insomnia and to inform the development of appropriately timed circadian-based treatments.

Durability of treatment response to zolpidem with three different maintenance regimens: a preliminary study.

BACKGROUND AND AIM: At present, there is no consensus regarding how to medically manage chronic insomnia in the long term. The unstated standard of practice is for patients to use hypnotics intermittently. The present study aimed to compare a partial reinforcement strategy with nightly and intermittent dosing strategies for its potential as a maintenance therapy. METHODS: A mixed model was used in the study. One between-subjects factor: group (n = 4). One repeated-measures factor: time (12 weekly assessments). A total of 74 subjects with chronic Insomnia were treated with 10 mg zolpidem for 4 weeks. Treatment respondents were randomized to nightly dosing with 10 mg or 5 mg (QHS-10 and QHS-5), intermittent dosing with 10 mg (IDS-10 [3-5 days weekly]), or partial reinforcement dosing with 10 mg (PRS-10 [nightly pill use with 50% active medication and 50% placebos]) for 12 weeks. RESULTS: It was found, in compliant subjects (n = 55), that all four strategies evaluated maintained treatment response over time (ie, prevented or delayed relapse). For the subjects that remained in remission, the subjects in the intermittent dosing group (IDS-10) group exhibited poorer sleep continuity. CONCLUSIONS: While best considered a preliminary study, the present findings suggest that the partial reinforcement strategy may be a viable means toward maintaining treatment gains over time with less active medication.

Neurobehavioral performance impairment in insomnia: relationships with self-reported sleep and daytime functioning.

STUDY OBJECTIVES: Despite the high prevalence of insomnia, daytime consequences of the disorder are poorly characterized. This study aimed to identify neurobehavioral impairments associated with insomnia, and to investigate relationships between these impairments and subjective ratings of sleep and daytime dysfunction. DESIGN: Cross-sectional, multicenter study. SETTING: Three sleep laboratories in the USA and Australia. PATIENTS: Seventy-six individuals who met the Research Diagnostic Criteria (RDC) for Primary Insomnia, Psychophysiological Insomnia, Paradoxical Insomnia, and/or Idiopathic Childhood Insomnia (44F, 35.8 ± 12.0 years [mean ± SD]) and 20 healthy controls (14F, 34.8 ± 12.1 years). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants completed a 7-day sleep-wake diary, questionnaires assessing daytime dysfunction, and a neurobehavioral test battery every 60-180 minutes during an afternoon/evening sleep laboratory visit. Included were tasks assessing sustained and switching attention, working memory, subjective sleepiness, and effort. Switching attention and working memory were significantly worse in insomnia patients than controls, while no differences were found for simple or complex sustained attention tasks. Poorer sustained attention in the control, but not the insomnia group, was significantly associated with increased subjective sleepiness. In insomnia patients, poorer sustained attention performance was associated with reduced health-related quality of life and increased insomnia severity. CONCLUSIONS: We found that insomnia patients exhibit deficits in higher level neurobehavioral functioning, but not in basic attention. The findings indicate that neurobehavioral deficits in insomnia are due to neurobiological alterations, rather than sleepiness resulting from chronic sleep deficiency.