Safety of carotid artery stent in repetitive transcranial magnetic stimulation—The histopathological proof from swine carotid artery

Introduction Repetitive transcranial magnetic stimulation (rTMS), including theta burst stimulation (TBS), is considered helpful for functional recovery in post-stroke patients. However, the safety is a common concern forusingr TMS for neuro-rehabilitation and research in patients with stents. Method Prolonged continuous theta burst stimulation (cTBS) with 1200 pulses at 50% of maximum output of Magstim Super Rapid2 was delivered in three different angles to a carotid stent placed in an isolated fresh swine carotid artery or on a table at a distance of 5 cm. The possible migration and temperature change of the stent caused by cTBS was monitored by video recording and a digital thermometer, respectively. Histopathological study with hematoxylin and eosin stain were done on the vessel wall to identify possible micro thermal injury. Results Stents in vessels did not cause any significant morphology change, such as thermal damage, after cTBS was given at three different angles. Neither visible migration nor significant temperature elevation was induced by cTBS. Conclusion There was no temperature change, thermal injury or migration after prolonged TBS at a high intensity, suggesting TBS is safe for clinical neuro-rehabilitation and physiological assessments in stroke patients with vascular stents.