Department of Life Sciences, Ben-Gurion University, Beer Sheva, Israel.
Department of Life Sciences, Ben-Gurion University, Beer Sheva, Israel.
Clin Neurophysiol. 2014 Feb;125(2):336-43. doi: 10.1016/j.clinph.2013.07.013. Epub 2013 Aug 30.
To compare the ability of an H-coil and figure-8 coil to stimulate different motor cortex regions.
The resting (rMT) and active (aMT) motor thresholds were measured for the right hand APB and leg AHB muscles in 10 subjects, using an H-coil and a figure-8 coil. The electric field distribution induced by the coils was measured in a head model. The combination of the hand and leg MTs with the field measurements was used to determine the depth of hand and leg motor areas via the intersection points.
The rMT and aMT of both APB and AHB were significantly lower for the H-coil. The ratio and difference between the leg and hand rMT and aMT were significantly lower for the H-Coil. Electric field measurements revealed significantly more favorable depth profile and larger volume of stimulation for the H-coil. The averaged intersection for the APB was at a distance from coil of 1.83±0.54cm and at an intensity of 97.8±21.4V/m, while for the AHB it was at a distance of 2.73±0.44cm and at an intensity of 118.6±21.3V/m.
The results suggest a more efficient activation of deeper motor cortical regions using the H-coil.
The combined evaluation of MTs by H- and figure-8 coils allows measurement of the individual depth of different motor cortex regions. This could be helpful for optimizing stimulation parameters for TMS treatment.
比较 H 线圈和 8 字形线圈刺激不同运动皮层区域的能力。
在 10 名受试者中，使用 H 线圈和 8 字形线圈测量右手 APB 和腿部 AHB 肌肉的静息（rMT）和活动（aMT）运动阈值。在头模型中测量线圈引起的电场分布。通过交点确定手和腿运动区的深度，将手和腿 MT 与场测量相结合。
H 线圈的 rMT 和 aMT 均显著低于 APB 和 AHB。H 线圈的腿与手 rMT 和 aMT 的比值和差值均显著降低。电场测量显示 H 线圈具有更有利的深度分布和更大的刺激体积。APB 的平均交点距离线圈为 1.83±0.54cm，强度为 97.8±21.4V/m，而 AHB 的平均交点距离线圈为 2.73±0.44cm，强度为 118.6±21.3V/m。
结果表明 H 线圈更有效地激活更深的运动皮层区域。
H 线圈和 8 字形线圈联合测量 MT 可测量不同运动皮层区域的个体深度。这对于优化 TMS 治疗的刺激参数可能会有所帮助。
