This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vgontzas, A. N. Articles by Vela-Bueno, A. Search for Related Content PubMed PubMed Citation Articles by Vgontzas, A. N. Articles by Vela-Bueno, A. Related Collections Sleep and Biological Rhythms

Differences in Nocturnal and Daytime Sleep Between Primary and Psychiatric Hypersomnia: Diagnostic and Treatment Implications

From the Sleep Research and Treatment Center and Department of Psychiatry (A.N.V., E.O.B., A.K., C.C.), Pennsylvania State University College of Medicine, Hershey, PA; and Sleep Disorders Center and Autonomous University (A.V.-B.), Madrid, Spain.

Address reprint requests to: Alexandros N. Vgontzas, MD, Pennsylvania State University, College of Medicine, Department of Psychiatry, 500 University Dr., Hershey, PA 17033. Email: axv3{at}psu.edu

OBJECTIVE: The differential diagnosis of primary (idiopathic) vs. psychiatric hypersomnia is challenging because of the lack of specific clinical or laboratory criteria differentiating these two disorders and the frequent comorbidity of mental disorders in patients with primary hypersomnia. The aim of this study was to assess whether polysomnography aids in the differential diagnosis of these two disorders.

METHODS: After excluding patients taking medication and those with an additional diagnosis of sleep-disordered breathing, we compared the nocturnal and daytime sleep of 82 consecutive patients with a diagnosis of either primary hypersomnia (N = 59) or psychiatric hypersomnia (N = 23) and normal control subjects (N = 50).

RESULTS: During nocturnal sleep, patients with psychiatric hypersomnia showed significantly higher sleep latency, wake time after sleep onset, and total wake time and a significantly lower percentage of sleep time than patients with primary hypersomnia and control subjects (p < .05). In addition, the daytime sleep of patients with psychiatric hypersomnia was significantly higher in terms of sleep latency, total wake time, and percentage of light (stage 1) sleep and lower in terms of percentage of sleep time and stage 2 sleep than in patients with primary hypersomnia and control subjects (p < .05). The daytime sleep of patients with primary hypersomnia as compared with that of control subjects was characterized by lower sleep latency and total wake time and a higher percentage of sleep time (p < .05). Finally, a sleep latency of less than 10 minutes or a sleep time percentage greater than 70% in either of the two daytime naps was associated with a sensitivity of 78.0% and a specificity of 95.7%.

CONCLUSIONS: Our findings indicate that psychiatric hypersomnia is a disorder of hyperarousal, whereas primary hypersomnia is a disorder of hypoarousal. Polysomnographic measures may provide useful information in the differential diagnosis and treatment of these two disorders.

Key Words: primaryhypersomnia • psychiatric hypersomnia • polysomnography

Abbreviations: ANCOVA = analysis of covariance; ANOVA = analysis ofvariance; BMI = body mass index; DSM-IV = Diagnosticand Statistical Manual of Mental Disorders, fourth edition; EDS = excessive daytime sleepiness; REM = rapid eye movement; SL = sleep latency; ST = sleep time; TWT = total waketime; WTASO = wake time after sleep onset.

This article has been cited by other articles:

				T. J. Young and M. H. Silber Hypersomnias of central origin. Chest, September 1, 2006; 130(3): 913 - 920. [Abstract] [Full Text] [PDF]

				C. Guilleminault and S. N. Brooks Excessive daytime sleepiness: A challenge for the practising neurologist Brain, August 1, 2001; 124(8): 1482 - 1491. [Abstract] [Full Text] [PDF]