Suffering from insomnia? Try a treatment that's shown some efficacy, but needs more research from contributors like you.
What causes insomnia?
A person suffering from insomnia has trouble in falling and staying asleep. Insomnia might occur due to physical or psychological stress, or may be a side effect of a pharmacological medication. It is considered that cortical activity, when pathologically altered, leads to insomnia. This regulation of cortical activation follows circadian rhythms that allow the transition between sleep and wakefulness.
Fortunately, studies have shown that neuromodulation through non-invasive brain stimulation in the form of transcranial direct current stimulation can alter cortical excitability and can be used to probe effects on different parameters of sleep. It has been shown that tDCS has the ability to cause modifications in EEG parameters of a person’s sleep and wake such as synchronization.
How does tDCS work?
In tDCS, the current that flow in the brain is triggered through a positive and a negative electrode (anode and cathode, respectively). The basic mechanisms of tDCS include polarization of neuronal membranes under the electrodes placed on the skull. Anodal and cathodal tDCS show antagonistic effects on cortical excitability. Anodal stimulation increases cortical excitability, whereas, on the other hand, cathodal tDCS decreases cortical excitability. Hence, the placing of the anode over a particular target cortical area of the brain is capable of modifying the excitability of this area by rising depolarization of cortical neuronal cells.
Experiments on Insomnia Using tDCS:
In an experiment carried out by Lukas Frase and colleagues, the effects of two different tDCS parameters and a sham stimulation on the sleep cycle of 19 healthy participants was compared.
Bi-frontal anodal stimulation, seemed to increase the arousal, and consequently, decreased the total sleep time in comparison to the other two interventions. Bi-frontal cathodal stimulation, expected to decrease arousal, did not increase the total sleep time, may be because there is a ‘ceiling’ or limit after which the good sleepers do not sleep any more. EEG analysis finally proved that the anodal stimulation increased the arousal, while cathodal stimulation did the other way and decreased the arousal.
It was, at last, concluded that by using anodal tDCS total sleep time can be decreased. The researchers hope this knowledge can contribute to future treatments for disturbed arousal and sleep.
Another research study comprising of 26 neuropsychiatric patients ( with stroke, dysphagia, pain, hereditary spastic paraparesis, Parkinson’s disease, aphasia, depression) were made to go through tDCS treatment. tDCS montage for each pathology was different. The current intensity of the stimulation was kept at 2mA and was delivered for 5 consecutive days, 20 min per day. The sleep quality at baseline (T0) and after the tDCS treatment (T1) was assessed.
Despite of the fact that the sample size was small and different tDCS montages were used, data from the observational study showed that anodal tDCS for five consecutive days enhanced the quality of sleep and improved its efficiency.
tDCS could be a non-invasive and valuable new tool for managing sleep disorders. Researchers that studied the total sleep time and other sleep disturbances propose that tDCS may be potentially beneficial to modulate cortical activity linked with insomnia and to adjust sleep adequacy.
Modulation of Total Sleep Time by Transcranial Direct Current Stimulation (tDCS). (2016, may 4). Retrieved from Neuropsychopharmacology: https://www.nature.com/articles/npp201665
TDCS Can Change Sleep Duration. (2016, october 7). Retrieved from bipolar news: http://bipolarnews.org/?p=3884
The Modulatory Effect of Sleep on tDCS. (2017, sept). Retrieved from http://epubs.surrey.ac.uk/845444/1/FINAL%20THESIS_James%20Ebajemito.pdf
Transcranial Direct Current. (n.d.). Retrieved from SCIENCE MEDICAL CENTRE: https://www.jscimedcentral.com/SleepMedicine/sleepmedicine-3-1060.pdf
Transcranial direct current stimulation improves sleep in patients with post-polio syndrome. (2013, aug 26). Retrieved from Science Daily: https://www.sciencedaily.com/releases/2013/08/130826143724.htm