title: Sleep phasic events in dysthymic patients: a comparative study with normal controls.
abstract: Among psychiatric entities, dysthymic patients provide a good model for studies on minor disturbances in sleep organization because they present borderline abnormalities in their night sleep that concern mainly slow wave sleep. A study on sleep phasic events was performed to evaluate abnormalities in sleep microstructure. Therefore, for all subjects--normal controls and dysthymic patients--the following phasic activities were scored: K-complexes, vertex sharp transients, posterior occipital transients, delta paroxysms, theta bursts, microarousals, and awakenings. Furthermore, other sleep EEG patterns, such as REM with spindles, and intermediate stages, were assessed. The following results were obtained: 1) dysthymic patients have less K-complexes and vertex sharp transients, with lower densities of these events; 2) they have a reduced number of microarousals, with an increased rate of awakenings; 3) patients present a higher incidence of other events such as theta bursts, POSTs, REM with spindles, and intermediate stages. These results suggest that the analysis of phasic events is useful for the discrimination between normal and pathologic sleep, even when there are only minor differences in terms of macrostructure.
authors.affiliation: Laboratory of EEG, Centro Estudos Egas Moniz, Hospital de Santa Maria, Lisboa, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Paiva
authors.forename: F
authors.initials: F
authors.lastname: Arriaga
authors.forename: A
authors.initials: A
authors.lastname: Rosa
authors.forename: J N
authors.initials: JN
authors.lastname: Leitão
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology; D001143:Arousal / Q000502:physiology; D003866:Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008875:Middle Aged; D017286:Polysomnography; D011569:Psychiatric Status Rating Scales; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology