Ineffectiveness of electrosleep in chronic primary insomnia

Brain stimulation techniques as novel treatment options for insomnia: A systematic review

Despite the success of cognitive behavioural therapy for insomnia and recent advances in pharmacotherapy, many patients with insomnia do not sufficiently respond to available treatments. This systematic review aims to present the state of science regarding the use of brain stimulation approaches in treating insomnia. To this end, we searched MEDLINE, Embase and PsycINFO from inception to 24 March 2023. We evaluated studies that compared conditions of active stimulation with a control condition or group. Outcome measures included standardized insomnia questionnaires and/or polysomnography in adults with a clinical diagnosis of insomnia. Our search identified 17 controlled trials that met inclusion criteria, and assessed a total of 967 participants using repetitive transcranial magnetic stimulation, transcranial electric stimulation, transcutaneous auricular vagus nerve stimulation or forehead cooling. No trials using other techniques such as deep brain stimulation, vestibular stimulation or auditory stimulation met the inclusion criteria. While several studies report improvements of subjective and objective sleep parameters for different repetitive transcranial magnetic stimulation and transcranial electric stimulation protocols, important methodological limitations and risk of bias limit their interpretability. A forehead cooling study found no significant group differences in the primary endpoints, but better sleep initiation in the active condition. Two transcutaneous auricular vagus nerve stimulation trials found no superiority of active stimulation for most outcome measures. Although modulating sleep through brain stimulation appears feasible, gaps in the prevailing models of sleep physiology and insomnia pathophysiology remain to be filled. Optimized stimulation protocols and proof of superiority over reliable sham conditions are indispensable before brain stimulation becomes a viable treatment option for insomnia.

Age-Limited Effects of Low-Frequency Transcutaneous Electric Nerve Stimulation on Insomnia: A 4-Week Multi-Center, Randomized Controlled Study

OBJECTIVE

Insomnia disorder is a common condition with considerable harmful effects on health. We investigated the therapeutic efficacy and safety of low-frequency transcutaneous electric nerve stimulation (LF-TENS) as an alternative treatment option for insomnia disorder.

METHODS

A 4-week, multi-center, randomized controlled study was conducted. A total of 160 individuals aged 40 to 80 years with insomnia disorder were included and randomized to the experimental group receiving active device (n=81) or control group receiving sham device (n=79). Both groups used the device for four weeks, more than five days a week. The participants also completed pre- and post-intervention assessment with questionnaires, sleep diaries, wrist actigraphy, and blood tests.

RESULTS

There was no significant between-group difference in the changes of mood and sleep parameters and blood test results among the two study groups. Meanwhile, in the exploratory sub-group analysis of patients aged over 60 years, the experimental group showed better improvement after intervention in the change of Pittsburgh Sleep Quality Index (PSQI) score (-2.63±3.25 vs. -1.20±2.28, p=0.039; Cohen's d=0.99 vs. 0.45) and blood cortisol level (-1.65±3.37 μg/dL vs. -0.16±3.49 μg/dL, p=0.007; Cohen's d=0.56 vs. 0.05). In addition, no serious adverse reaction occurred during the study period in both groups.

CONCLUSION

The effect of LF-TENS was limited to older patients aged over 60 years, which might be related to the modulation of hypothalamic-pituitary-adrenal axis activity.

The effect of cranial electrotherapy stimulation on sleep in healthy women

OBJECTIVE

Cranial electrotherapy stimulation (CES) is considered to be a potential treatment for insomnia. Women are more likely to suffer from insomnia than men. Therefore we studied the effect of CES on sleep efficiency in young healthy women.

METHODS

A randomized, controlled clinical study was conducted on 40 women (age 18-35 years) without sleep disorders. Each subject underwent two nights of polysomnography in a sleep center. During the second night, we applied CES with a commercial device (Alpha-Stim 100) using either active or sham stimulation (double-blinded). Sleep was evaluated with respect to differences between the active and sham modes. Sleep electroencephalogram (EEG) analysis was applied to determine frequency changes.

RESULTS

In our study we found no evidence of any direct influence of the Alpha-Stim 100 on sleep. After application of CES, we determined no significant differences between the active group and the control group (sham). Using EEG spectral analysis there was evidence of a frequency-lowering influence on the low-α frequency band (8-10 Hz).

CONCLUSIONS

At most we may assume a reproducible effect on the α frequency measured in the EEG for application of CES with current levels  >100 µA and presumably also with frequencies  >0.5 Hz, with application directly at the cranium. We found no influence on sleep parameters. The effect on the low-α band evidenced in quantitative EEG analysis would require further investigation in a study with sufficient effect size.

SIGNIFICANCE

This is the first study to investigate the effects of CES with polysomnography during and after therapy. Our study contributes to the few controlled trials that have been conducted to study CES and its effects on the EEG α band. Highlights • This is the first study to investigate the effects of the Alpha-Stim in polysomnography during and subsequent to therapy. • In a quantitative electroencephalogram analysis we studied the data obtained for systematic changes. • To minimize placebo effects in patients with sleep disorders, we conducted the tests on subjects without such disorders.

Modulation of Total Sleep Time by Transcranial Direct Current Stimulation (tDCS)

Arousal and sleep are fundamental physiological processes, and their modulation is of high clinical significance. This study tested the hypothesis that total sleep time (TST) in humans can be modulated by the non-invasive brain stimulation technique transcranial direct current stimulation (tDCS) targeting a 'top-down' cortico-thalamic pathway of sleep-wake regulation. Nineteen healthy participants underwent a within-subject, repeated-measures protocol across five nights in the sleep laboratory with polysomnographic monitoring (adaptation, baseline, three experimental nights). tDCS was delivered via bi-frontal target electrodes and bi-parietal return electrodes before sleep (anodal 'activation', cathodal 'deactivation', and sham stimulation). Bi-frontal anodal stimulation significantly decreased TST, compared with cathodal and sham stimulation. This effect was location specific. Bi-frontal cathodal stimulation did not significantly increase TST, potentially due to ceiling effects in good sleepers. Exploratory resting-state EEG analyses before and after the tDCS protocols were consistent with the notion of increased cortical arousal after anodal stimulation and decreased cortical arousal after cathodal stimulation. The study provides proof-of-concept that TST can be decreased by non-invasive bi-frontal anodal tDCS in healthy humans. Further elucidating the 'top-down' pathway of sleep-wake regulation is expected to increase knowledge on the fundamentals of sleep-wake regulation and to contribute to the development of novel treatments for clinical conditions of disturbed arousal and sleep.

Top-down control of arousal and sleep: Fundamentals and clinical implications

Mammalian sleep emerges from attenuated activity in the ascending reticular arousal system (ARAS), the main arousal network of the brain. This system originates in the brainstem and activates the thalamus and cortex during wakefulness via a well-characterized 'bottom-up' pathway. Recent studies propose that a less investigated cortico-thalamic 'top-down' pathway also regulates sleep. The present work integrates the current evidence on sleep regulation with a focus on the 'top-down' pathway and explores the potential to translate this information into clinically relevant interventions. Specifically, we elaborate the concept that arousal and sleep continuity in humans can be modulated by non-invasive brain stimulation (NIBS) techniques that increase or decrease cortical excitability. Based on preclinical studies, the modulatory effects of the stimulation are thought to extend to subcortical arousal networks. Further exploration of the 'top-down' regulation of sleep and its modulation through non-invasive brain stimulation techniques may contribute to the development of novel treatments for clinical conditions of disrupted arousal and sleep, which are among the major health problems worldwide.

Efficacy of cranial electric stimulation for the treatment of insomnia: a randomized pilot study

OBJECTIVES

This pilot study examined the potential efficacy of cranial electric stimulation for the treatment of insomnia.

DESIGN

The researchers tested the hypothesis through a randomized, double-blind, and placebo controlled clinical trial. The researchers approached eligible subjects who scored 21 or above on the Pittsburgh Insomnia Rating Scale. The researchers then randomly assigned the subjects to receive either an active or sham device. Each study subject received 60min of active or sham treatment for five days. Following each intervention the subjects completed a sleep log, as well as three and ten days later.

SETTING

The researchers conducted the study among active duty service members receiving mental health care on the Psychiatry Continuity Service (PCS), Walter Reed National Military Medical Center in Bethesda, MD.

MAIN OUTCOME MEASURES

The study's primary outcome variables were the time to sleep onset, total time slept, and number of awakenings as reported by the subjects in the serial sleep logs. The researchers identified a nearly significant increase in total time slept after three cranial electric stimulation treatments among all study subjects. A closer examination of this group revealed an interesting gender bias, with men reporting a robust increase in total time slept after one treatment, decay in effect over the next two interventions, and then an increase in total time slept after the fourth treatment. The researchers speculate that the up and down effect on total time slept could be the result of an insufficient dose of cranial electric stimulation.

Cognitive approaches to insomnia

Cognition is a broad term that refers to all mental activities and encompasses attention, perception, memory, reasoning, beliefs, attributions and expectations. The aim of the present paper is to draw together the major research findings relating to the importance of cognition in insomnia. Although the research to date has tended to focus on the role of unwanted intrusive thought (also known as worry or cognitive arousal), there is evidence that a broad range of cognitive processes are important for a full understanding of insomnia. These include beliefs, attributions, expectations, perception and attention. The treatment implications of this evidence are discussed, as are priorities for future research.

Quantitative analysis of the electroencephalogram during cranial electrotherapy stimulation

OBJECTIVE

Normal individuals were used to quantitate electroencephalographic (EEG) changes during concurrent administration of 0.5 and 100 Hz cranial electrotherapy stimulation (CES).

METHODS

Twelve normal, right-handed males were used in a randomized, double-blind crossover design study. A 3 amplifier system incorporating noise-cancellation was used to collect one channel of EEG (O1-Cz configuration) for 30 min. Either 0.5, 100 Hz, or sham CES treatment was administered for 20 min of each session. Statistical analyses were applied to time- and frequency-domain EEG variables.

RESULTS

Relative to sham control, 0.5 and 100 Hz CES caused the alpha band mean frequency to shift downward. Additionally, 100 Hz CES also caused a decrease of the alpha band median frequency and beta band power fraction.

CONCLUSIONS

Both 0.5 and 100 Hz CES provide frequency distribution shifts that suggest beneficial changes in mental state. However, compared to 0.5 Hz CES, 100 Hz CES effected a greater overall change. It is suggested that similar tests be performed on individuals with various behavioral and neurological disorders to determine if comparable EEG changes can be realized and correlated with beneficial effects of CES therapy.

Melatonin and sleep qualities in healthy adults: pharmacological and expectancy effects

The impact of expectancy on melatonin's effects on sleep qualities was investigated. Both the pharmacological dose of 6 mg of melatonin and the expectation of receiving melatonin were predicted to improve subjective ratings of sleep qualities. The balanced placebo design varied 2 factors within-subjects: actual treatment and expected treatment. Adults (N = 53; 21 men and 32 women) between the ages of 26 and 71 years were administered either 6 mg of melatonin or a placebo for 8 nights. An instructional manipulation directed participants' expectations. Participants rated their nightly sleep experiences. Results revealed that feelings upon awakening differed between genders and that expecting melatonin increased ratings of sleep continuity. Most important, high ratings of "grogginess/tiredness" were associated with receiving melatonin, regardless of expectancy, as well as with receiving placebo when melatonin was expected. Overall, the findings underscore the need to consider expectancy and gender differences in research on melatonin and sleep experiences.

A study of the effects of cranial electrical stimulation on attention and concentration

There have been several anecdotal accounts that cranial electrical stimulation (CES) enhances attention and the ability to learn new tasks in a normal population, but only one published investigation confirms that CES improves attention using the Alpha Stim CES (Madden and Kirsch, 1987). The purpose of this study was to corroborate the findings of Madden and Kirsch, using more precise measures of attention, such as a Continuous Performance Test (CPT). A pretest and posttest CPT was given to two groups using the LISS CES device. The control group consisted of twenty-one subjects who received the placebo treatment. The experimental group of thirty-one subjects received twenty minutes of CES. Four measures of the CPT show significant gains in attention: Number of Hits, p =.010 Hit RT ISI Change, p =.016, Risk Taking, p =.055; and Attentiveness, p =.054. Based on subjects who demonstrated improvement by one standard deviation on two different measures of the CPT, thirty-one percent of the experimental group improved versus four percent of the control group. The use of CES as a method of increasing attention is a promising area that requires further investigation.

The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research

Despite the prevalence of sleep complaints among psychiatric patients, few questionnaires have been specifically designed to measure sleep quality in clinical populations. The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire which assesses sleep quality and disturbances over a 1-month time interval. Nineteen individual items generate seven "component" scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of scores for these seven components yields one global score. Clinical and clinimetric properties of the PSQI were assessed over an 18-month period with "good" sleepers (healthy subjects, n = 52) and "poor" sleepers (depressed patients, n = 54; sleep-disorder patients, n = 62). Acceptable measures of internal homogeneity, consistency (test-retest reliability), and validity were obtained. A global PSQI score greater than 5 yielded a diagnostic sensitivity of 89.6% and specificity of 86.5% (kappa = 0.75, p less than 0.001) in distinguishing good and poor sleepers. The clinimetric and clinical properties of the PSQI suggest its utility both in psychiatric clinical practice and research activities.

Influence of diffuse brain stimulation (DBS) on human sleep. I. Sleep pattern changes

A 20 min period of diffuse brain stimulation (DBS), administered just before sleep onset in 16 human subjects, appeared to alter significantly the first sleep cycle of the succeeding sleep. The length of the first sleep cycle and the amount of REM sleep increased, whereas a shift from deep to more superficial NREM sleep occurred. This effect of DBS on sleep is discussed with respect to data from the literature on the effect of narcotic DBS and on that of local brain stimulation in animals.

The efficacy of electrosleep therapy

A review of the literature on the efficacy of electrosleep therapy is presented. The vast majority of non-double-blind based reports are very optimistic about its effectiveness, but the inferences from the double-blind based research are much less positive. It is concluded that the efficacy of electrosleep therapy has not yet been satisfactorily demonstrated.

A clinical trial of electrosleep therapy with a psychiatric inpatient sample

The study assessed the effectiveness of electrosleep therapy in the treatment of depression, anxiety, and sleep difficulties in a small, heterogenous sample of psychiatric inpatients. A double-blind format was employed, one group receiving active treatment while the other received simulated treatment. The results showed active electrosleep to be no better than placebo in bettering quality of sleep or in lessening symptoms of depression or anxiety.