Article

A normative study of the maintenance of wakefulness test (MWT).

Sleep Disorders Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Electroencephalography and Clinical Neurophysiology 12/1997; 103(5):554-62. DOI: 10.1016/S0013-4694(97)00010-2
Source: PubMed

ABSTRACT The maintenance of wakefulness test (MWT) is a daytime polysomnographic procedure which quantifies wake tendency by measuring the ability to remain awake during soporific circumstances. We present normative data based on 64 healthy subjects (27 males and 37 females) who adhered to uniform MWT procedural conditions including polysomnographic montage, illuminance level, seating position, room temperature, meal timing, and subject instructions. When allowed a maximum trial duration of 40 min, subjects' mean sleep latency to the first epoch of sustained sleep was 35.2 +/- 7.9 min. The lower normal limit, defined as two standard deviations below the mean, was 19.4 min. Calculation of data on the basis of a maximum trial duration of 20 min and sleep latency to the first appearance of brief sleep (a microsleep episode or one epoch of any stage of sleep) yielded a mean sleep latency of 18.1 +/- 3.6 min and a lower normal limit of 10.9 min. Sleep latency scores were significantly higher than those previously reported in patients with disorders of excessive somnolence. Therefore, the MWT appears to be a useful procedure in differentiating groups with normal daytime wake tendency from those with impaired wake tendency and in identifying individuals with pathologic inability to remain awake under soporific circumstances.

0 Bookmarks
 · 
102 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Sleep onset is typically monitored using EEG, EMG and EOG. Scoring rules of Rechtschaffen and Kales (RK) are normally used in 30 s epochs for scoring wakefulness (S0) and sleep stages (S1, S2, S3, S4 and REM). One daytime sleepiness test is Maintenance of Wakefulness Test (MWT) where the subject is instructed to stay awake under soporific circumstances. We analyzed 17 of 40 minute MWT recordings using linear and non linear analysis to study vigilance fluctuations beyond 30 s RK scoring. Using adaptive epoch lengths with minimum epoch duration of 2 seconds a total of 768 wake-sleep and sleep-wake transitions were used to study change in fractal dimension (FD) in sleep onset and in following awakenings. Time domain fractal dimension was calculated using Higuchi algorithm (kmax=8, 16) for 2 seconds before and 2 seconds after each sleep onset and awakenings. Ratios of dimensions were calculated. Using kmax=8: For sleep onset (S0-S1) transitions fractal dimension changed from 1.28±0.08 to 1.32±0.09 and fractal dimension ratio was 1.03±0.07 and for sleep-wake (S1-S0) transitions ratio was 1.00±0.06. Using kmax=16: For sleep onset (S0-S1) transitions fractal dimension changed from 1.52±0.09 to 1.52±0.10 and fractal dimension ratio was 1.00±0.05 and for sleep-wake (S1-S0) transitions ratio was 1.04±0.06. Findings using kmax=8 are in contradiction of lower frequencies (theta activity of S1) resulting in lower FD than higher frequencies (alpha activity of S0). Our results indicate that fractal dimension could be used as an assisting parameter in computer assisted sleep onset detection.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In a study of acute sleep deprivation in healthy male volunteers randomized to double-blind treatment with lisdexamfetamine dimesylate (20, 50, or 70 mg), placebo control, or an active control (armodafinil 250 mg), Maintenance of Wakefulness Test data were compared using a generalized estimating equation analysis to eliminate the need for unequivocal sleep latency imputation. Compared with placebo across all Maintenance of Wakefulness Tests, all active treatments were associated with lower risk of falling asleep (risk ratio [95% confidence interval]): 0.45 (0.27-0.76; P = 0.0026), 0.10 (0.05-0.20; P < 0.0001), and 0.05 (0.02-0.14; P < 0.0001) for 20, 50, and 70 mg lisdexamfetamine dimesylate, respectively, and 0.11 (0.06-0.21; P < 0.0001) for the active control. Sleep-risk ratios were similar for lisdexamfetamine dimesylate 50 or 70 mg and for the active control, but lisdexamfetamine 20 mg was associated with a greater risk of falling asleep compared with the active control (4.13 [1.97-8.67]; P = 0.0002). Generalized estimating equation analysis detected wake-promoting effects of active treatments and eliminating data imputation, suggesting model utility in future studies.
    Journal of Clinical Psychopharmacology 10/2014; 34(5):642-644. · 3.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Summary Attention deficit hyperactivity disorder is one of the most common child and adolescent psychiatric disorders. Probably a dysfunctional arousal regulation may play an important role in its pathogenesis. According to this hypothesis ADHD children may present an hypoarousal state with impaired daytime vigilance when confrontated with monotonous, repetetive tasks. We assessed the daytime wakefulness of 23 ADHD children and 6 children with excessive somnolence (narcolepsy, idiopathic CNS hypersomnia) using the Maintenance of Wakefulness Test (MWT) as a measure to determine objectively a subjects' ability to stay awake under soporific conditions. Results indicate that there is no impaired daytime wakefulness in ADHD children, whether their nighttime sleep was disturbed or not. Mean sleep latencies across all MWT trials were similar for both groups groups (17.2 min. vs 16.3 min). In contrast children with an increased daytime sleepiness presented a shortened mean sleep latency during the trials (8.9 min). Aditionally more children of this group fell asleep during MWT compared to ADHD children (72 % vs 40.6 %). We speculate that due to the occurrence of attention problems in both disorders, the MWT might become a feasable, objective instrument in clinical practice for differential diagnostic. German Zusammenfassung Einführung Die Aufmerksamkeits-Defizit-Hyperaktivitätsstörung gehört zu den häufigsten kinder- und jugendpsychiatrischen Krankheitsbildern. Wissenschaftliche Befunde zur Pathogenese der Störung sprechen für das Vorliegen einer Arousalstörung mit einer resultierenden Unfähigkeit der Betroffenen, die Vigilanz bei monotonen, häufige Wiederholungen beinhaltenden Aufgabenstellungen aufrechtzuerhalten. Methodik Der Maintenance of Wakefulness Test (MWT) stellt ein objektives Messverfahren zur Überprüfung der Tagesvigilanz dar, die wir bei 23 Kindern mit einer Aufmerksamkeits-Defizit-Hyperaktivitätsstörung sowie bei 6 Kindern mit erhöhter Tagesmüdigkeit (Narkolepsie, Idiopathische zentrale Hypersomnie) untersuchten. Ergebnisse Die Testergebnisse mit den über drei Versuchsdurchgänge hinweg berechneten mittleren Einschlaflatenzen sprechen dafür, dass die Tagesvigilanz bei Kindern mit einer Aufmerksamkeits-Defizit-Hyperaktivitätsstörung nicht beeinträchtig zu sein scheint, unabhängig davon, ob sie eine begleitende Schlafstörung aufweisen oder nicht (17,2 Min. vs 16,3 Min). Im Gegensatz hierzu zeigten Kinder mit einer Störung, die mit einer erhöhten Tagesmüdigkeit einhergeht, deutlich verkürzte Einschlaflatenzen (8,9 Min). Insgesamt schliefen sie auch während der Untersuchungsdurchgänge häufiger ein als Kinder mit einer ADHS (72,2 % vs 40,6 %). Schlussfolgerung Aus den uns vorliegenden Ergebnissen ergeben sich Hinweispunkte, dass der Maintenance of Wakefulness Test ein sinnvolles, ergänzendes Messinstrument darstellen könnte in der Differenzialdiagnostik von Aufmerksamkeitsstörungen im Kindes- und Jugendalter.
    Somnologie - Schlafforschung und Schlafmedizin 12/2001; 5(4).

Full-text (2 Sources)

Download
24 Downloads
Available from
Jul 4, 2014