Magsood Hamzah, Syeda Farheen, Holloway Kathryn, Carmona Ivan C, Hadimani Ravi L
Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States.
Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, United States.
Front Hum Neurosci. 2020 Apr 3;14:123. doi: 10.3389/fnhum.2020.00123. eCollection 2020.
Patients with advanced Parkinson's disease (PD) often receive deep brain stimulation (DBS) treatment, in which conductive leads are surgically implanted in the brain. While DBS treats tremor and rigidity, patients often continue to suffer from speech and swallowing impairments. There is preliminary evidence that transcranial magnetic stimulation (TMS) of the cortex may be beneficial for these symptoms. However, the potential electromagnetic interactions of the strong magnetic fields from TMS on the conductive leads is unknown, and the combination therapy has not been approved for use. In this article, we report an experimental study of the safety of combining DBS and TMS. We fabricated an anatomically accurate head and brain phantom with electrical conductivities matching cerebrospinal fluid and averaged conductivity of gray and white matter. Induced current on an implanted DBS probe in the brain phantom was measured. Our results show that TMS will induce current values in the range or higher than typical DBS stimulation current. Thus, the combination of TMS/DBS treatment might cause over-stimulation in the brain when stimulated directly over the DBS lead with 100% TMS current intensity.
晚期帕金森病（PD）患者常接受深部脑刺激（DBS）治疗，即通过手术将导电电极植入大脑。虽然DBS可治疗震颤和僵硬，但患者往往仍存在言语和吞咽障碍。有初步证据表明，对皮层进行经颅磁刺激（TMS）可能有助于缓解这些症状。然而，TMS产生的强磁场与导电电极之间潜在的电磁相互作用尚不清楚，且这种联合治疗尚未获批使用。在本文中，我们报告了一项关于DBS与TMS联合应用安全性的实验研究。我们制作了一个头部和脑部模型，其解剖结构精确，电导率与脑脊液以及灰质和白质的平均电导率相匹配。测量了脑部模型中植入的DBS探针上的感应电流。我们的结果表明，TMS将诱导出与典型DBS刺激电流相当或更高的电流值。因此，当以100%的TMS电流强度直接在DBS电极上方进行刺激时，TMS/DBS联合治疗可能会导致大脑过度刺激。
