Journal of Sleep Sciences

Validity and Reliability of a Self-Report Likert-Type Measure of Nightmare Frequency

William Kelly — 2024-04-13

Background and Objective: Nightmare frequency is typically measured using interval and ordinal, but rarely Likert-type, scales. The current study aimed to examine the validity and reliability of a Likert-type measure of retrospective nightmare frequency.
Materials and Methods: Participants included a convenience sample of undergraduate students. They completed a recent-ly developed Likert-type nightmare frequency item, an established Nightmare Frequency Scale, an estimate of nightmare frequency over the past week, and measures of hypothetically related variables including neuroticism, psychological dis-tress, and trauma symptoms. Convergent and discriminant validity was evaluated through relationships between the Likert-type nightmare frequency item with other nightmare measures and hypothetically related variables. Reliability was esti-mated using a correction for attenuation approach designed to provide a conservative estimate of single-item reliability.
Results: The sample included 233 (119 female, 51.1%; 114 male, 48.9%) university students (mean age: 19.05 ± 1.91). The average convergent validity coefficient between the Likert-type nightmare frequency item and other nightmare measures (r = 0.647) was significantly different (z = 5.45, P < 0.001) from its average correlation coefficient with hypo-thetically related measures (r = 0.256). The single-item reliability coefficient was 0.722.
Conclusion: The reliability and convergent and discriminant validity of the Likert-type nightmare frequency item were supported.

A Comparative Study of Architecture and Quality of Sleep among Juvenile Myoclonic Epilepsy Patients and Healthy Individuals Attending Tertiary Care Hospital in Central India

Ashwin Lathiya — 2024-04-13

Background and Objective: Primary sleep disorders are common in patients with epilepsy. Seizures, epileptiform discharges, and antiepileptic drugs alter the sleep architecture of patients with juvenile myoclonic epilepsy (JME). We evaluated sleep architecture and its quality in these patients.
Materials and Methods: Thirty patients with JME (11 men and 19 women with mean age of 21.10 ± 4.55 years) and 30 healthy controls underwent overnight polysomnography (PSG). Sleep quality and daytime sleepiness were assessed using Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), respectively.
Results: Myoclonus and generalized tonic-clonic seizures (GTCS) were present in all patients with JME, while absence seizures were in 13.3%. Sleep deprivation was the most frequent precipitating factor for seizures (56.6%) followed by fatigue, sound, and photic stimulation. Patients with JME reported a statistically significant drop in sleep efficiency (P<0.001) with prolonged sleep onset latency (P<0.001). There was prolongation in the N1 stage of non-rapid eye movement (NREM) sleep (P=0.002), and reduction in the N2 stage of NREM (P<0.001) and rapid eye movement (REM) sleep (P<0.001). The median PSQI score was higher in patients with JME, suggesting poor sleep quality (P<0.001), and the daytime sleepiness was not different as indicated by the similar median ESS score (P=0.033).
Conclusion: Our results suggest a significant alteration in the sleep architecture of patients with JME with reduced sleep efficiency and poor sleep quality. The possible role of the disease itself is suggested for these alterations as a simi-lar trend was also observed in drug naïve patients.

Transcranial Direct Current Stimulation (tDCS) as a Therapeutic Tool for Chronic Insomnia

Tahereh Motevalizadeh — 2024-03-03

Background and Objective: Insomnia is the most common sleep problem which is associated with cortical over-excitation. Transcranial direct-current stimulation (tDCS) potentially modifies insomnia-related cortical state. There-fore, we tested the hypothesis that insomnia severity can be modulated by tDCS.
Materials and Methods: The current study was conducted with a pretest-posttest design and a control group. A total of 32 women with insomnia were randomly categorized into an intervention group (active stimulation) and a control group (sham stimulation). In the intervention group, tDCS was used with an intensity of 2mA for 20 to 30 minutes during 12 sessions (3 times a week). Anodal stimulation was performed on the left primary motor cortex (M1) and cathodal stimulation was performed on the right dorsal lateral prefrontal cortex (DLPFC). The control group received sham stim-ulation for 20 to 30 minutes during 12 sessions (3 times a week). All participants were evaluated before and after the intervention using the Insomnia Severity Index (ISI) and Positive Affect and Negative Affect Schedule (PANAS).
Results: The results of univariate analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) showed a significant difference between the tDCS group and the sham group in terms of reduction in the severity of insomnia. We also observed that positive affect increased and negative affect decreased following insomnia treatment (P ≤ 0.005).
Conclusion: The results of our study indicated that performing our designed tDCS protocol for treating insomnia can be effective in treating insomnia and improving positive and negative affect.

Predicting Sleep Quality Based on Mindfulness among the Patients who Suffer from Irritable Bowel Syndrome (IBS): Investigating the Mediating Role of Self-Regulation and Rumination

Amir Mahdi Katani — 2024-03-03

Background and Objective: Some studies have investigated the quality of sleep among patients with irritable bowel syndrome (IBS); however, they are not comprehensive. The current study was conducted to predict quality of sleep among patients with IBS based on mindfulness, the mediating role of self-regulation, and rumination.
Materials and Methods: This was a cross-sectional study in form of structural equation modeling (SEM). The samples included 231 patients with IBS, and the measures were Mindfulness, Self-regulation, Rumination, and Pittsburgh Sleep Quality Index (PSQI) scales. In addition, the SPSS and R software were used to analyze data.
Results: Mindfulness, along with the mediating role of self-regulation and rumination could predict sleep quality among patients with IBS (P < 0.01), and the fit indices indicated the model fit.
Conclusion: Mindfulness, rumination, and self-regulation had an important role in sleep problems among patients with IBS.

Dreaming in Individuals with Blindness

Mortaza Zangeneh Soroush — 2024-03-03

What is dreaming in blind individuals like? For years, this question has been attracting much attention in science. However, dreaming is still, to a large extent, an unknown phenomenon for researchers (1, 2). Previous studies show that dreams include different sensory modalities and experiences (3).