Counter S A
Neurology Department, Harvard University, Cambridge, MA 02138.
Electroencephalogr Clin Neurophysiol. 1993 Oct;89(5):341-8. doi: 10.1016/0168-5597(93)90074-y.
The effects of transcranial electromagnetic stimulation (TEMS) on the cellular morphology of the cortex, cerebellum, and brain-stem were systematically investigated in rabbits exposed to 1000 pulsed stimuli at 100% maximum stimulation level (2.0 Tesla at the skull) over a 12 month period with a 5 cm circular magnetic coil positioned over the cranium. Also, the acute effects of TEMS on heart rate and respiration were examined. (1) T1 and T2 weighted magnetic resonance images (MRI) of 1-3 mm sections in both sagittal and axial planes revealed no evidence of gross morphological changes or subtler tissue damage to the cerebrum, cerebellum, or brain-stem. (2) Light microscopic examination of 60 microns hematoxylin-eosin/Cresyl Violet Luxol Fast Blue stained sections of the brain-stem, cerebellum, and cerebral cortex showed no TEMS-related changes in cellular organization or histological damage. (3) Autonomic activity as reflected by heart rate was also unaffected by high intensity TEMS. Normal heart rate was maintained during repeated TEMS at 100% of maximum. (4) Respiration rate was briefly altered at the time of the stimulus, but returned to normal immediately after the stimulus. These findings in experimental animals revealed no biohazardous effects on the brain following extensive exposure to high intensity, low frequency time-varying magnetic field stimulation from the coil of a clinical instrument.
在12个月的时间里，使用一个直径5厘米的圆形磁线圈放置在兔颅骨上，以100%最大刺激水平（颅骨处为2.0特斯拉）对兔子施加1000次脉冲刺激，系统地研究了经颅电磁刺激（TEMS）对皮质、小脑和脑干细胞形态的影响。此外，还检查了TEMS对心率和呼吸的急性影响。（1）矢状面和轴面1 - 3毫米切片的T1和T2加权磁共振成像（MRI）显示，大脑、小脑或脑干没有明显的形态学变化或细微的组织损伤迹象。（2）对脑干、小脑和大脑皮质60微米苏木精 - 伊红/甲酚紫卢戈氏固蓝染色切片的光学显微镜检查显示，细胞组织或组织学损伤方面没有与TEMS相关的变化。（3）由心率反映的自主神经活动也不受高强度TEMS的影响。在以100%最大强度重复进行TEMS期间，心率保持正常。（4）呼吸频率在刺激时短暂改变，但刺激后立即恢复正常。实验动物的这些发现表明，在临床仪器的线圈对其进行长时间高强度、低频时变磁场刺激后，未发现对大脑有生物危害作用。
