Effect of valproate on sleep patterns disturbed by epilepsy.

Nocturnal epilepsy is a neurological disease that has a significant effect on sleep. Various treatments have been implemented to help mitigate these effects and improve patients' quality of life. The use of experimental animal models for epilepsy has facilitated efficacy assessment and the development of different medications to treat the symptoms of this disease. The objective of this study was to evaluate the effect of valproate on sleep patterns altered by epilepsy. Chronically implanted Wistar rats were used to study sleep patterns over three consecutive days under different experimental conditions. The animals were separated into two groups. The first day was considered the control recording; on the second day, one group received pentylenetetrazol (PTZ) alone, and the other group received valproate prior to induction of convulsive seizures with PTZ administration. The results show that in addition to its antiepileptic effect, valproate has hypnotic properties. It is considered to facilitate the action of GABAergic mechanisms to mitigate the effect of convulsive seizures and increase the occurrence of sleep.

Evaluation of the Heart Rhythm Coherence Ratio During Sleep: A Pilot Study With Polysomnography.

The psychophysiological coherence model proposes that a heart rhythm pattern, known as heart rhythm coherence (HRC), is associated with dominant parasympathetic activity and the entrainment of respiratory function, blood pressure, and heart rhythms. Although the HRC pattern has primarily been assessed during wakefulness, changes in cardiac and autonomic activity that occur during sleep stages can also be associated with the HRC pattern. The objective of this study was to examine whether any differences in the HRC pattern could be detected among various sleep stages. Eighteen healthy young individuals participated in this study. Two consecutive polysomnographic (PSG) recordings were obtained from each participant, several segments of cardiac activity were obtained from the second PSG. The HRC pattern was quantitatively evaluated by calculating the HRC ratio (HRCR). The highest peaks in the coherence band (Coher-Peak), 0.1-Hz index, respiratory sinus arrhythmia (RSA), and heart rate (HR) were evaluated. A Friedman test showed significant differences among sleep stages in the Coher-Peak, 0.1-Hz index, RSA, and HR; the Coher-Peak and RSA values were lower in rapid eye movement (REM) sleep, while the 0.1-Hz and HR values were higher in REM sleep. Post hoc analyses identified significant differences between the N2 and REM sleep stages. Among the various sleep stages, HR and RSA measurements behaved independently of the HRC pattern, and the HRC pattern did not appear to be associated with the 0.1 Hz frequency. Further studies are required to identify the characteristics of the HRC pattern during sleep.

Sleep architecture and the absence of trapezius muscle atonia in women with chronic whiplash-associated disorder: a pilot study.

Sleep disturbances frequently occur in people with whiplash-associated disorder (WAD) and have been evaluated using questionnaires or actigraphy. It is not clear whether sleep architecture, as assessed by polysomnography (PSG), is altered in individuals with WAD. Additionally, in people with WAD, muscle dysfunction is observed during tasks performed during wakefulness. Thus, this study aimed to analyze the sleep architecture of patients with chronic WAD as well as to evaluate trapezius muscle activity during sleep. Nine women with chronic WAD and nine healthy age-matched women participated in the study. Two PSG recordings were conducted for each participant. Surface electromyography signal samples of the right and left trapezius, and mentonian muscles were obtained from N2, N3, and REM sleep stages for analysis. Significant differences were found in the percentages of total sleep time in the N1 and N2 stages between the two groups. While the muscle tone of the three muscles analyzed decreased progressively across the sleep stages in the healthy group, in the chronic WAD group, this decrement was observed only in the mentonian muscle, and the trapezius muscle continued to exhibit the same muscle tone throughout the sleep stages without atonia during REM sleep. The absence of trapezius muscle atonia during REM sleep in the WAD patients may be related to dysfunction of the mechanisms that regulate motor activity.