Transcranial direct current stimulation (tDCS) is a neurorehabilitation technique that has demonstrated its effectiveness in numerous areas, including the rehabilitation of patients with epilepsy (1). With the increasing prevalence of epilepsy globally, innovative treatments like tDCS are becoming increasingly relevant.
Epilepsy is characterized by an abnormal increase in the excitability of neurons. tDCS can be useful in this context, as it can modulate the excitability of neurons and, therefore, control seizures. Specifically, a negative (or cathodic) direct current can be applied to decrease neuronal excitability and, consequently, reduce epileptic seizures.
What is tDCS and how Does it Work?
tDCS is a non-invasive brain stimulation modality that uses low-intensity electrical currents to modulate the activity of neurons in specific brain regions (2). This technique has the ability to increase or decrease the excitability of brain cells, depending on the direction of the current.
tDCS is already being implemented in some neurorehabilitation clinics, providing patients with an additional treatment option that can complement their regimen of antiepileptic drugs. At FIVAN, we have been applying tDCS and Transcranial Magnetic Stimulation (TMS) for years in cases of drug-resistant epilepsy with good results.
Although tDCS is generally safe, it is important to remember that it must be administered under the supervision of a trained healthcare professional. Patients should be properly evaluated by a neurologist to determine if they are appropriate candidates for tDCS and to establish the most appropriate stimulation protocol for them.
tDCS and Epilepsy
tDCS has been tested in cases of epilepsy over the past two decades to reduce both the frequency of seizures and epileptiform discharges on the electroencephalogram (EEG). Most patients in these studies were resistant to medication and received cathodal tDCS stimulation directed to the area with the greatest abnormalities on the EEG. The results were remarkable: 84{e82d97dd9764c61214c58cac6dd9b37da6ffa5921c380452d273401b1dd0074a}% of the studies reported a reduction in seizure frequency and 43{e82d97dd9764c61214c58cac6dd9b37da6ffa5921c380452d273401b1dd0074a}% observed a decrease in the rate of epileptiform discharges on the EEG.
A meta-analysis conducted in 2018 by Matsumoto and his team concluded that tDCS can reduce the frequency and intensity of epileptic seizures (3). Another recent study by Fregni et al. also supported these findings, providing further evidence of the efficacy of tDCS in the management of epilepsy (4).
Benefits and Limitations of tDCS
One of the main benefits of tDCS is its non-invasive nature, which makes it safe and well-tolerated by patients. In addition, it has the potential to be used as a complementary treatment to antiepileptic drugs, which may further improve its effectiveness.
However, tDCS has some limitations. The effects of tDCS can vary depending on numerous factors, such as the age, gender, and health status of the individual, as well as the intensity and duration of the stimulation (5). Furthermore, more research is still needed to establish best practices for the application of tDCS in epilepsy, including the most effective stimulation protocols and the identification of patients who would benefit most from this treatment.
Future of tDCS in Epilepsy
The future of tDCS in the treatment of epilepsy looks promising. With continued research and clinical trials, we can expect to better understand how to maximize the benefits of tDCS and minimize its potential adverse effects.
One possible direction for future research could be the development of personalized stimulation protocols based on the individual characteristics of patients. This could allow for a more precise application of tDCS, potentially improving its effectiveness and reducing any possible adverse effects.
In Summary
Transcranial direct current stimulation is emerging as a promising technique in neurorehabilitation, with the potential to improve the lives of people with epilepsy. Although there is still much to learn about tDCS, studies to date have demonstrated its potential to reduce the frequency and intensity of epileptic seizures, thereby improving the quality of life of patients.
References
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- Fregni, F., & Pascual-Leone, A. (2007). Technology Insight: noninvasive brain stimulation in neurology-perspectives on the therapeutic potential of rTMS and tDCS. Nature clinical practice. Neurology, 3(7), 383–393.
- Nitsche, M. A., Cohen, L. G., Wassermann, E. M., Priori, A., Lang, N., Antal, A., … & Pascual-Leone, A. (2008). Transcranial direct current stimulation: State of the art 2008. Brain Stimulation, 1(3), 206-223.
- Matsumoto, H., & Ugawa, Y. (2017). Adverse events of tDCS and tACS: a review. Clinical Neurophysiology Practice, 2, 19-25.
- Fregni, F., Nitsche, M. A., Loo, C. K., Brunoni, A. R., Marangolo, P., Leite, J., … & Pascual-Leone, A. (2015). Regulatory considerations for the clinical and research use of transcranial direct current stimulation (tDCS): review and recommendations from an expert panel. Clinical research and regulatory affairs, 32(1), 22-35.
- Bikson, M., Grossman, P., Thomas, C., Zannou, A. L., Jiang, J., Adnan, T., … & Woods, A. J. (2016). Safety of transcranial direct current stimulation: evidence based update 2016. Brain Stimulation, 9(5), 641-661.
