Science
What is Transcranial Electrical Stimulation (tES)?
Transcranial electrical stimulation (tES) is a non-invasive procedure that applies weak electrical currents through electrodes placed on the scalp to specific brain regions. This method modulates brain activity to enhance cognitive functions and treat neurological symptoms.
Basics
of the transcranial electrostimulation
Transcranial electrical stimulation (tES) delivers a weak electrical current through precisely placed electrodes on the scalp to specific regions of the brain. This current modulates brain activity in both healthy and diseased brains, influencing aspects such as neuronal excitability, cerebral blood flow, and brain metabolism.
Depending on the type of stimulation, brain activity can be increased, inhibited, or adjusted to specific frequencies in the target area. For instance, if the goal is to enhance cognitive functions, the stimulation is tailored to increase excitability in the brain regions where the function to be improved is localized. Anodal stimulation of the dorsolateral prefrontal cortex, for example, can contribute to the enhancement of memory.
Areas of Application
Neurostimulation in Alzheimer’s Disease
This is particularly important in indications where brain activity is reduced in specific regions due to illness. The neurostimulation for Alzheimer’s dementia specifically targets this property to reactivate affected brain areas. Current research suggests that this can lead to cognitive improvements.
Electrical stimulation of the brain can also be used to promote blood circulation, stimulate metabolism, and modulate the neurotransmitter system in a way that can intentionally influence cognitive processes and moods of relevance in neurology and psychiatry. Adjusting brain waves to specific frequencies allows for the targeted strengthening of frequency bands affected by disease that are responsible for cognitive functions.
Frequency-Specific Treatment Approaches
For example, the gamma activity at 40 Hz is reduced in Alzheimer’s and dementia patients, making neurostimulation a promising treatment approach for Alzheimer’s dementia. Patients with depression exhibit a changed activity in the alpha frequency range, which can be positively influenced by targeted brain electrotherapy.
Types of Stimulations and Their Effects
With these components, the Miamind® brain stimulator home device represents an advanced brain electrotherapy for at-home users.
Transcranial Direct Current Stimulation (tDCS)
tDCS uses constant, weak direct currents as a brain electrotherapy to modulate the excitability of nerve cells. Depending on polarity, neurons can be activated (anodal stimulation) or inhibited (cathodal stimulation). This method is particularly suitable as a home device for brain stimulation, as it is easy to use and very safe.
Transcranial Alternating Current Stimulation (tACS)
In tACS, oscillating electric fields are used to synchronize natural brain rhythms. According to ongoing research in neurostimulation for Alzheimer’s dementia, this technique shows promise as it may help restore disrupted gamma rhythms at 40 Hz, which are essential for memory and attention.
Safety and Tolerability
Transcranial electrostimulation is considered an exceptionally safe treatment method. The most common side effects are mild and transient: slight tingling or itching under the electrodes (30-70%), headaches (12%), fatigue (35-60%), and brief skin reddening (2-10%). Severe side effects occur very rarely, and there are no reports of lasting damage with proper use.
Clinical Effectiveness
Studies indicate that tES may be effective in various neurological and psychiatric disorders. Particularly in dementia treatment and cognitive impairments, promising results are observed. With Miamind®, these approaches are further researched and optimized within personalized neurostimulation through individual adaptations for each patient.
Discover the Future of Personalized Neurostimulation
Are you interested in the innovative Miamind® technology for personalized neurostimulation? As the world’s first fully individualized home device for brain stimulation, Miamind® offers a new dimension of brain electrotherapy.
FAQ: Frequently Asked Questions
for transcranial electrical stimulation (tES)
What is transcranial electrical stimulation?
Transcranial electrical stimulation is a non-invasive procedure in which weak electrical currents are applied through electrodes to selectively stimulate certain brain regions, modulating brain activity and improving neurological functions.
What does transcranial electrical stimulation do?
The stimulation modulates the excitability of nerve cells, improves cerebral blood flow, stimulates brain metabolism, and can positively influence cognitive functions such as memory, attention, and concentration.
What is electrical stimulation good for?
Electrostimulation of the brain is used for various neurological and psychiatric disorders, including depression, Alzheimer’s disease, epilepsy, chronic pain, and cognitive rehabilitation after a stroke.
What does transcranial mean?
“Transcranial” means “through the skull” – the electrical impulses are transmitted through the scalp and penetrate the skull bone to reach the underlying brain tissue.
How does electrical stimulation feel?
Most patients only feel a slight tingling or prickling under the electrodes during the treatment. The stimulation is painless and well-tolerated – many describe the sensation as pleasantly relaxing.
How long does a tES treatment with Miamind take?
A typical Miamind® treatment session lasts about 20-30 minutes and can be conveniently done at home. The total treatment duration is determined individually by the treating physician.
How effective is tES?
The effectiveness of tES is scientifically proven and varies depending on the indication. Personalized approaches like Miamind® show particularly promising results through the individual adjustment of stimulation parameters.
What side effects does transcranial electrical stimulation have?
tES is very safe with only mild, temporary side effects: slight tingling (70%), headaches (12%), fatigue (35%), or skin redness (2%). Severe side effects are extremely rare.
Is tea good for your brain?
Yes, tES can have positive effects on brain function when applied properly and in consultation with your treating physician. It improves blood circulation and can contribute to the long-term improvement of cognitive abilities, without harming the brain.
References
Transcranial Electrical Stimulation
- Wischnewski, M., Mantell, K. E. & Opitz, A. Identifying regions in prefrontal cortex related to working memory improvement: A novel meta-analytic method using electric field modeling. Neurosci. Biobehav. Rev. 130, 147–161 (2021).
- Sudbrack-Oliveira, P. et al. Transcranial direct current stimulation (tDCS) in the management of epilepsy: A systematic review. Seizure - Eur. J. Epilepsy 86, 85–95 (2021).
- Sprugnoli, G. et al. Impact of multisession 40Hz tACS on hippocampal perfusion in patients with Alzheimer’s disease. Alzheimers Res. Ther. 13, 203 (2021). 13, 203 (2021).
- Zheng, X., Alsop, D. C. & Schlaug, G. Effects of Transcranial Direct Current Stimulation (tDCS) on Human Regional Cerebral Blood Flow. NeuroImage 58, 26–33 (2011).
- Nitsche, M. A. et al. Serotonin affects transcranial direct current-induced neuroplasticity in humans. Biol. Psychiatry 66, 503–508 (2009).
- Fröhlich, F., Sellers, K. K. & Cordle, A. L. Targeting the neurophysiology of cognitive systems with transcranial alternating current stimulation. Expert Rev. Neurother. 15, 145–167 (2015).
- Kasten, F. H., Dowsett, J. & Herrmann, C. S. Sustained Aftereffect of α-tACS Lasts Up to 70 min after Stimulation. Front. Hum. Neurosci. 10, (2016). 10, (2016).
- Santarnecchi, E. et al. Gamma tACS over the temporal lobe increases the occurrence of Eureka! moments. Sci. Rep. 9, 5778 (2019).
Potential Clinical Applications
- Gauthier, S., Rosa-Neto, P., Morais, J. & Webster, C. World Alzheimer Report 2021: Journey through the diagnosis of dementia. World Alzheimers Dis. Int. 1–314 (2021).
- Verret, L. et al. Inhibitory Interneuron Deficit Links Altered Network Activity and Cognitive Dysfunction in Alzheimer Model. Cell 149, 708–721 (2012).
- Kuchibhotla, K. V. et al. Abeta plaques lead to aberrant regulation of calcium homeostasis in vivo resulting in structural and functional disruption of neuronal networks. Neuron 59, 214–225 (2008).
- Shaftel, S. S., Griffin, W. S. T. & O’Banion, M. K. The role of interleukin-1 in neuroinflammation and Alzheimer disease: an evolving perspective. J. Neuroinflammation 5, 7 (2008).
- Sprugnoli, G. et al. Impact of multisession 40Hz tACS on hippocampal perfusion in patients with Alzheimer’s disease. Alzheimers Res. Ther. 13, 203 (2021). 13, 203 (2021).
- Mateo, C., Knutsen, P. M., Tsai, P. S., Shih, A. Y. & Kleinfeld, D. Entrainment of Arteriole Vasomotor Fluctuations by Neural Activity Is a Basis of Blood-Oxygenation-Level-Dependent ‘Resting-State’ Connectivity. Neuron 96, 936-948.e3 (2017).
- Smeralda, C. L. et al. The role of parvalbumin interneuron dysfunction across neurodegenerative dementias. Ageing Res. Rev. 101, 102509 (2024).
- De Paolis, M. L. et al. Transcranial alternating current stimulation (tACS) at gamma frequency: an up-and-coming tool to modify the progression of Alzheimer’s Disease. Transl. Neurodegener. 13, 33 (2024). 13, 33 (2024).
- Cappon, D. et al. Tele-supervised home-based transcranial alternating current stimulation (tACS) for Alzheimer’s disease: a pilot study. Front. Hum. Neurosci. 17, (2023).
- Dhaynaut, M. et al. Impact of 40 Hz Transcranial Alternating Current Stimulation on Cerebral Tau Burden in Patients with Alzheimer’s Disease: A Case Series. J. Alzheimers Dis. JAD 85, 1667–1676 (2022).
- Bréchet, L. et al. Patient-Tailored, Home-Based Non-invasive Brain Stimulation for Memory Deficits in Dementia Due to Alzheimer’s Disease. Front. Neurol. 12, (2021).
- Palop, J. J. & Mucke, L. Network abnormalities and interneuron dysfunction in Alzheimer disease. Nat. Rev. Neurosci. 17, 777–792 (2016).
- Seoane, S., Van Den Heuvel, M., Acebes, Á. & Janssen, N. The subcortical default mode network and Alzheimer’s disease: a systematic review and meta-analysis. Brain Commun. 6, fcae128 (2024).
- Benussi, A. et al. Exposure to gamma tACS in Alzheimer’s disease: A randomized, double-blind, sham-controlled, crossover, pilot study. Brain Stimulat. (2021) doi:10.1016/j.brs.2021.03.007.
- Benussi et al. Increasing Brain Gamma Activity Improves Episodic Memory and Restores Cholinergic Dysfunction in Alzheimer’s Disease. (2022).
- Rezakhani, S., Amiri, M., Hassani, A., Esmaeilpour, K. & Sheibani, V. Anodal HD-tDCS on the dominant anterior temporal lobe and dorsolateral prefrontal cortex: clinical results in patients with mild cognitive impairment. Alzheimers Res. Ther. 16, 27 (2024).
- Boggio, P. S. et al. Prolonged visual memory enhancement after direct current stimulation in Alzheimer’s disease. Brain Stimulat. 5, 223–230 (2012).
- McKendrick, R., Falcone, B., Scheldrup, M. & Ayaz, H. Effects of Transcranial Direct Current Stimulation on Baseline and Slope of Prefrontal Cortex Hemodynamics During a Spatial Working Memory Task. Front. Hum. Neurosci. 14, 64 (2020).
- Im, J. J. et al. Effects of 6-month at-home transcranial direct current stimulation on cognition and cerebral glucose metabolism in Alzheimer’s disease. Brain Stimul. Basic Transl. Clin. Res. Neuromodulation 12, 1222–1228 (2019).
- Gangemi, A., Colombo, B. & Fabio, R. A. Effects of short- and long-term neurostimulation (tDCS) on Alzheimer’s disease patients: two randomized studies. Aging Clin. Exp. Res. 33, 383–390 (2021).