title: Correlation between K complex, periodic leg movements (PLM), and myoclonus during sleep in paraplegic adults before and after an acute physical activity.
abstract: K complex is the characteristic wave of stage II of sleep. The relationship between periodic limb movements (PLM) and the restless legs syndrome (RLS), and the incidence of K complexes and alpha activity has been previously described. The aim of the present study was to evaluate the effect of an acute physical activity upon K complex, PLM, and myoclonus during sleep in individuals who were paraplegic. We evaluated 84 polysomnograms from 28 volunteers with a spinal cord injury at the level of T7-T12, obtained during three consecutive nights. On day 3, the volunteers were submitted to a test of maximum effort (manual cycloergometer, with the equipment Cybex Met 300, with a progressive load increase of 12.5 w, every 2 min). The analysis of the polysomnographic recordings showed a positive correlation between the incidence of K complex and limb movements on nights 1, 2 and 3. Similarly, a correlation between the incidence of K complex and myoclonus was observed on nights 1, 2 and 3. An increased incidence of the total K complex was seen on night 3, 36 h after the test maximum effort. Both total K complex and K complex/h were reduced on night 2, compared to basal recording (night 1). There was a reduction of sleep latency on night 2, whereas total sleeping time increased progressively on night 3, as well as REM phase on nights 2 and 3. These findings indicate that physical activity can effect or modulate the incidence of K complex and suggest that a positive correlation between PLM and K complex may occur in those who are paraplegic from a spinal cord injury. In conclusion, sleep can be consolidated after physical activity.
authors.affiliation: UNIFESP-EPM, Department of Psychobiology, Universidade Federal de Goiás-Catalãc, Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Mello
authors.forename: A C
authors.initials: AC
authors.lastname: Silva
authors.forename: A D
authors.initials: AD
authors.lastname: Rueda
authors.forename: D
authors.initials: D
authors.lastname: Poyares
authors.forename: S
authors.initials: S
authors.lastname: Tufik
mesh_terms: D000328:Adult; D004569:Electroencephalography; D005069:Evaluation Studies as Topic; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D007866:Leg; D009068:Movement / Q000502:physiology; D009207:Myoclonus / Q000209:etiology / Q000503:physiopathology*; D010264:Paraplegia / Q000209:etiology / Q000503:physiopathology*; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D013119:Spinal Cord Injuries / Q000150:complications