Sleep spindles in chronic psychophysiological insomnia

Spontaneous K-complexes in chronic psychophysiological insomnia

“…In our previous report, a higher number and a greater density of sleep spindles were depicted at the end of the night [34]. As such, a similar nightly distribution of phasic events was observed in both groups across nights.…”

“…Furthermore, Wauquier et al [35] did not compile the occurrence of sleep spindles and could not infer on the interaction between these two phasic events in this particular population. As such, if both K-complexes and sleep spindles have a similar functional role, our results suggest that sleepprotective mechanisms, as expressed by the number and density of K-complexes and sleep spindles [34], are not deficient in psychophysiological insomnia sufferers as compared with GS controls. Alternatively, if both phasic events have antagonistic functional roles, the K-complex being an arousal sign and the sleep spindle being a sleepprotective mechanism, the microstructure of Stage 2 sleep of psychophysiological insomnia sufferers does not display fewer or more signs of arousal than the one of GS controls does.…”

“…While the use of power spectral analysis (PSA) and magnetic resonance imaging had also suggested other signs of activation in the EEG of insomnia sufferers as compared with GS [14][15][16][17][18], sleep-protective mechanisms, as measured by the occurrence of spindles and K-complexes, have been poorly documented in chronic insomnia sufferers. Our group [34] has recently shown that the occurrence and density of sleep spindles were similar in GS controls and psychophysiological insomnia sufferers. To our knowledge, only one study, conducted by Wauquier et al [35], has compared the occurrence of well-defined spontaneous K-complexes during 5 min of ascending Stage 2 and descending Stage 2 in patients suffering from generalized epilepsy, insomnia, narcolepsy, and obstructive sleep apnea with those in control participants.…”

“…For a complete description of the sample and procedure, please refer to the work of Bastien et al [34].…”

Sensory gating in primary insomnia

“…Additionally, INS participants had significantly more spindles than GS. Findings regarding spindle rate in PI are sparse and mixed with investigators reporting either no group differences between individuals with (psychophysiological) insomnia (Bastien et al. , 2009a) or reduced spindling in individuals with sleep misperception (Besset et al.…”