Minimal heating of aneurysm clips during repetitive transcranial magnetic stimulation.

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulatory technique whose use in clinical practice has increased steadily since in 2008 the Food and Drug administration (FDA) approved the Neuronetics NeuroStar System for treatment of certain patients with medication-resistant major depression. Although generally well-tolerated, rTMS safety warrants special consideration in certain patient populations, such as those with prior cranial surgery and metallic implants where a plausible risk of heating or displacement of the metallic parts should be considered before treatment (Rossi et al., 2009, 2011; Rotenberg et al., 2007; Rotenberg and Pascual-Leone, 2009). Among these are patients who have undergone subarachnoid aneurysm clip ligation. As no clinical safety data are available to assess the risk to health of rTMS in patients with intracranial aneurysm clips, we performed the present experiment aimed to measure whether an aneurysm clip composed of the most common cobalt–chromium–nickel alloy (Co–Cr–Ni) may be heated by rTMS.