Skin Lesions as Signs of Neuroenhancement in Sport.

Background: Neuroenhancement in sports, through pharmacological and non-pharmacological methods, is a complex and highly debated topic with no definitive regulatory framework established by the World Anti-Doping Agency (WADA). The hypothesis that dermatological changes could serve as observable biomarkers for neurodoping introduces a novel and promising approach to detecting and understanding the physiological impacts of cognitive enhancers in athletes. As neurodoping methods become increasingly sophisticated, developing objective, reliable, and non-invasive detection strategies is imperative. Utilizing dermatological signs as a diagnostic tool for internal neurophysiological changes could offer critical insights into the safety, fairness, and ethical considerations of cognitive enhancement in competitive sports. A systematic correlation between skin manifestations, the timeline of neurodoping practices, and the intensity of cognitive enhancement methods could provide healthcare professionals valuable tools for monitoring athletes' health and ensuring strict compliance with anti-doping regulations.

Methods: Due to the limited body of research on this topic, a systematic review of the literature was conducted, spanning from 2010 to 31 December 2024, using databases such as PubMed, Science Direct, and Google Scholar. This study followed the 2020 PRISMA guidelines and included English-language articles published within the specified period, focusing on skin lesions as adverse reactions to pharmacological and non-pharmacological neuroenhancement methods. The research employed targeted keywords, including "skin lesions AND rivastigmine", "skin lesions AND galantamine", "skin lesions AND donepezil", "skin lesions AND memantine", and "skin lesions AND transcranial direct electrical stimulation". Given the scarcity of studies directly addressing neurodoping in sports, the search criteria were broadened to include skin reactions associated with cognitive enhancers and brain stimulation. Eighteen relevant articles were identified and analyzed.

Results: The review identified rivastigmine patches as the most used pharmacological method for neuroenhancement, with pruritic (itchy) skin lesions as a frequent adverse effect. Donepezil was associated with fewer and primarily non-pruritic skin reactions. Among non-pharmacological methods, transcranial direct current stimulation (tDCS) was notably linked to skin burns, primarily due to inadequate electrode-skin contact, prolonged exposure, or excessive current intensity. These findings suggest that specific dermatological manifestations could serve as potential indicators of neurodoping practices in athletes.

Conclusions: Although specific neuroenhancement methods demonstrate distinctive dermatological side effects that might signal neurodoping, the current lack of robust clinical data involving athletes limits the ability to draw definitive conclusions. Athletes who engage in neurodoping without medical supervision are at an elevated risk of adverse dermatological and systemic reactions. Skin lesions, therefore, could represent a valuable early diagnostic marker for the inappropriate use or overuse of cognitive-enhancing drugs or neuromodulation therapies. The findings emphasize the need for focused clinical research to establish validated dermatological criteria for detecting neurodoping. This research could contribute significantly to the ongoing neuroethical discourse regarding the legitimacy and safety of cognitive enhancement in sports.