Safety of Repeated Transcranial Direct Current Stimulation in Impaired Skin

Abstract

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique based on the application of a weak, direct electric current via 2 or more electrodes (anode and cathode) over the scalp. One concern when applying tDCS is skin burn. It has been suggested that skin lesions are related to changes in the local dermal homeostasis, and therefore, caution is warranted in patients with skin diseases (Loo et al [Int J Neuropsychopharmacol. 2011;14:425-426]). In this context, we believe that it would be useful for this emerging field of tDCS to report the preliminary safety of repeated application of tDCS in a patient with vitiligo, an autoimmune disorder characterized by depigmentation sites of the skin or mucous membranes. We report the case of a 31-year-old male patient with schizophrenia who underwent 10-daily tDCS sessions. He has had generalized vitiligo since childhood, and despite previous treatment, no current dermatologic follow-up was being carried out. Depigmentation sites were evident in different areas, particularly under the anodal area. We found that repeated anodal tDCS in 1 patient did not lead to skin lesions when applied over a vitiligo skin area. Some of the procedures that we used to buffer changes in skin temperature may have contributed to prevent tDCS-induced skin damage. Nevertheless, the exact conditions that lead to skin lesion are still unknown. Given the growing use and testing of tDCS, continuous assessment and reporting of local adverse effects are still warranted especially in conditions with increased risk of skin lesions such as in dermatologic conditions, skin burns, and previous skin damage.

Transcranial Direct Current Stimulation in Schizophrenia

“…In addition, it is reassuring to note that the study in pediatric sample has not reported any significant problems either 18). Even in a schizophrenia patient with a dermatological condition, tDCS could be applied safely on the region with vitiligo 27). In many of the earlier reports, side effects that are reported have been mild itching and burning sensation, or mild but tolerable levels of pain at the electrode placement site.…”

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016

“…open wound) and is thus largely homogenous; but acne is typically not an exclusion for electrode locations. Skin preparation does not typically include significant abrasion (intended to remove epidermis; [20]), though cleaning of the skin/hair with saline or alcohol is sometimes used [21]. Standard tDCS electrodes (pads) are typically square 5×5 cm or 5×7 cm, though both smaller and larger electrode assemblies have been explored [22], as well as circular pads.…”

Methods for Specific Electrode Resistance Measurement During Transcranial Direct Current Stimulation

“…When established protocols are not followed, tDCS can produce significant skin irritation. Given that skin-sensation [3, 4, 5] and skin irritation are the primary risks of tDCS [6, 7], proper electrode preparation and then monitoring of electrode resistance are important to ensure the stimulation is reproducible and well tolerated (as well as sham reliability in clinical trials). The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety [8, 9, 10], where an unusually high electrode resistance is indicative of undesired electrochemical changes [11] or poor skin contact conditions.…”