Cost of scientific regulatory misclassification of non-invasive brain stimulation in Europe

• Misclassifying non-invasive brain stimulation in regulatory frameworks carries substantive costs for research and device positioning.¹
• A single-author opinion in Clinical Neurophysiology discusses EU regulatory strategy and device positioning for NIBS.^{1 1}

Weekly enrichment (2026-07-20)

• Implementing Regulation (EU) 2022/2347 (C/2022/8638), published 1 December 2022 and effective from 22 December 2022, reclassified repetitive TMS and low-intensity transcranial electrical stimulation devices without an intended medical purpose from Class I up to Class III, the highest risk tier that also covers invasive implants such as deep brain stimulators.²³
• The scope (MDR 2017/745, Annex XVI, Section 6) covers equipment applying electrical currents or magnetic/electromagnetic fields that penetrate the cranium to modify neuronal activity, explicitly including tDCS, tACS, transcranial random noise stimulation, and TMS, while excluding invasive devices.³
• This produces a paradox in which the same technology (for example TMS) is Class IIa when marketed with a medical purpose but Class III without one, with no clear scientific rationale for treating the non-medical version as higher risk.²⁴
• Because the rule applies only to devices “without an intended medical purpose,” the boundary is ambiguous for dual-use, cognitive-enhancement, and research-only devices, creating confusion about which studies fall under the MDR.²⁵
• The multi-author invited opinion this topic tracks (Antal et al., Clinical Neurophysiology 2024, volume 163, pages 280–291; corresponding author Andrea Antal, University Medical Center Göttingen) argues the MDR plus Annex XVI reclassification poses an “existential threat” to European NIBS research and treatment.²
• Critics contend the reclassification contradicts decades of accumulated safety data and rested on an inaccurate risk report adopted without consulting professional stakeholders; a separate “Note of concern” formally challenged the scientific evidence used to justify moving NIBS into Class III.²⁴
• A concrete research burden: under MDR Article 82, using a device outside its intended purpose can no longer rely on one-step local ethics approval and must be registered with National Competent Authorities, a process handled inconsistently across member states and adding cost, bureaucracy, and delay.²⁵
• The authors propose a fast-track National Competent Authority pathway allowing medical devices to be used in research settings (including non-intended use), arguing the Class III reclassification impedes clinical investigations with healthy volunteers without adding participant safety.²

Footnotes

1. https://www.sciencedirect.com/science/article/pii/S1388245725013252?dgcid=rss_sd_all ↩ ↩² ↩³

2. https://doi.org/10.1016/j.clinph.2024.03.039 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

3. https://health.ec.europa.eu/system/files/2023-12/mdcg_2023-5_en.pdf ↩ ↩²

4. https://doi.org/10.1016/j.brs.2025.01.012 ↩ ↩²

5. https://doi.org/10.1016/j.brs.2023.04.008 ↩ ↩²