Department of Neurosurgery, Inselspital, Bern University Hospital, Bern, Switzerland.
J Neurosurg. 2014 May;120(5):1015-24. doi: 10.3171/2014.1.JNS13909. Epub 2014 Mar 14.
The authors developed a new mapping technique to overcome the temporal and spatial limitations of classic subcortical mapping of the corticospinal tract (CST). The feasibility and safety of continuous (0.4-2 Hz) and dynamic (at the site of and synchronized with tissue resection) subcortical motor mapping was evaluated.
The authors prospectively studied 69 patients who underwent tumor surgery adjacent to the CST (< 1 cm using diffusion tensor imaging and fiber tracking) with simultaneous subcortical monopolar motor mapping (short train, interstimulus interval 4 msec, pulse duration 500 μsec) and a new acoustic motor evoked potential alarm. Continuous (temporal coverage) and dynamic (spatial coverage) mapping was technically realized by integrating the mapping probe at the tip of a new suction device, with the concept that this device will be in contact with the tissue where the resection is performed. Motor function was assessed 1 day after surgery, at discharge, and at 3 months.
All procedures were technically successful. There was a 1:1 correlation of motor thresholds for stimulation sites simultaneously mapped with the new suction mapping device and the classic fingerstick probe (24 patients, 74 stimulation points; r(2) = 0.98, p < 0.001). The lowest individual motor thresholds were as follows: > 20 mA, 7 patients; 11-20 mA, 13 patients; 6-10 mA, 8 patients; 4-5 mA, 17 patients; and 1-3 mA, 24 patients. At 3 months, 2 patients (3%) had a persistent postoperative motor deficit, both of which were caused by a vascular injury. No patient had a permanent motor deficit caused by a mechanical injury of the CST.
Continuous dynamic mapping was found to be a feasible and ergonomic technique for localizing the exact site of the CST and distance to the motor fibers. The acoustic feedback and the ability to stimulate the tissue continuously and exactly at the site of tissue removal improves the accuracy of mapping, especially at low (< 5 mA) stimulation intensities. This new technique may increase the safety of motor eloquent tumor surgery.
作者开发了一种新的映射技术，以克服经典皮质脊髓束（CST）皮质下映射的时间和空间限制。评估连续（0.4-2 Hz）和动态（在组织切除部位并与组织切除同步）皮质下运动映射的可行性和安全性。
作者前瞻性研究了 69 例肿瘤手术患者，这些患者的 CST 紧邻肿瘤（使用弥散张量成像和纤维追踪，距离<1cm），同时进行皮质下单极运动映射（短刺激，刺激间隔 4msec，脉冲持续时间 500μsec）和新的声运动诱发电位报警。通过将映射探针集成到新的抽吸装置的尖端，实现了连续（时间覆盖）和动态（空间覆盖）映射，其概念是该装置将与执行切除的组织接触。术后第 1 天、出院时和 3 个月评估运动功能。
所有手术均在技术上取得成功。使用新的抽吸式映射设备和经典指压探针同时映射的刺激部位的运动阈值存在 1:1 相关性（24 例患者，74 个刺激点；r(2)=0.98，p<0.001）。最低的个体运动阈值如下：>20mA，7 例；11-20mA，13 例；6-10mA，8 例；4-5mA，17 例；1-3mA，24 例。3 个月时，2 例（3%）患者出现持续性术后运动功能障碍，均由血管损伤引起。无患者因 CST 机械性损伤而出现永久性运动功能障碍。
连续动态映射被发现是一种可行的、符合人体工程学的技术，可定位 CST 的精确位置和与运动纤维的距离。声反馈和声刺激组织连续、精确地刺激在组织切除部位的能力提高了映射的准确性，尤其是在低（<5mA）刺激强度下。这项新技术可能会提高运动语言肿瘤手术的安全性。
