title: Longitudinal sleep EEG power spectral analysis studies in adolescents with minor head injury.
abstract: Power spectral analysis (PSA) was used to evaluate the longitudinal overnight electroencephalographic (EEG) sleep recordings of eight subjects, between the ages of 15 and 19 years, who had sustained a minor head injury (MHI). Recordings occurred within 72 h, 6 weeks, and 12 weeks following MHI. A conditioning night preceded the first study night during which EEG electrodes were in place and subjects slept at least 7.5 h with a mean sleep efficiency of 91%. PSA was performed on four channels of EEG data recorded from fronto-temporal (F3-T3, F4-T4), and temporal (T3-T5, T4-T6) electrodes. The three waveforms associated with sleep, Delta, Theta, and Alpha-1 were all significantly elevated within 72 h post-MHI. Over time all wave forms decreased in mean log power. Theta in rapid eye movement (REM) sleep Cycle 1 decreased significantly within 6 weeks postinjury. The greatest number of significant changes, over the 12-week period were recorded during the non-REM (NREM) sleep. Changes included (1) significant decreases in mean log power of Theta and Alpha-1 in Cycle 1 from fronto-temporal leads; (2) significant decreases in Delta, Theta, and Alpha-1 in Cycle 2 from fronto-temporal leads, and (3) significant decreases in Delta and Theta for consistency during Cycle 2 from temporal leads. The intrusion of Theta into the first REM cycle within 6 weeks and its subsequent decrease within 6 weeks suggested the initiation of recovery toward baseline values. This was followed by decreased levels of Theta power during NREM Cycles 1 and 2, and Delta power in Cycle 2, both of which approached their lowest levels within 12 wks. The decrease in Alpha-1 power occurred last. Alpha-1 remained elevated through both Cycles 1 and 2 of the 6th week and then showed a precipitous decrease between the sixth and twelfth week. These findings suggested that following MHI, the brain has a specific sequence of recovery as illustrated by Delta, Theta, and Alpha-1 powers requiring different time frames to reach their lowest levels.
authors.affiliation: College of Nursing, The University of Arizona, Tucson, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Parsons
authors.forename: L J
authors.initials: LJ
authors.lastname: Crosby
authors.forename: M
authors.initials: M
authors.lastname: Perlis
authors.forename: T
authors.initials: T
authors.lastname: Britt
authors.forename: P
authors.initials: P
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D006259:Craniocerebral Trauma / Q000503:physiopathology* / Q000523:psychology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages