Abejón D, Camacho M, Pérez-Cajaraville J, Ortego R, del Pozo C, del Saz J
Unidad de Dolor, Hospital Universitario Puerta de Hierro Majadahonda, Madrid.
Rev Esp Anestesiol Reanim. 2009 May;56(5):292-8. doi: 10.1016/s0034-9356(09)70398-6.
Patients being treated with spinal cord stimulation for chronic pain complain of variable paresthesias, particularly in relation to changes in posture. Such changes affect the great majority of patients with implantable pulse generators, requiring them to use the external programmer for avoidance of painful paresthesias or even to disconnect the generator, leading to loss of pain relief. The aim of this study was to determine the relationship between the pulse charge needed for stimulation and the patient's different postures.
Observational study of 70 patients treated with spinal cord stimulation in the following postures and situations: decubitus position, standing, seated, and walking. With the patients standing, we analyzed the thresholds of perception, pain, and pain relief, as well as the therapeutic range. Studies were performed in all patients. Later, data were analyzed by anatomical positioning of the stimulator (cervical, thoracic, sacral, occipital, or subcutaneous).
In the analysis of the therapeutic range in the overall group we identified statistically significant differences between decubitus and standing positions and between decubitus position and walking. At the level of the thoracic spine differences were identified between all positions except between standing and walking and between seated and decubitus positions. At the level of the cervical spine, no significant differences were detected. Analysis of the pulse charge showed a significant difference in the decubitus position, in which less charge was needed to achieve satisfactory stimulation. When electrodes implanted at the cervical and thoracic levels were compared, differences were found between standing and seated positions (P=.04) but none between decubitus position or walking and the other positions.
Stimulation systems are not currently designed to adapt to changes in distance between the electrodes and nerve fibers. Improvements are required in this respect.
接受脊髓刺激治疗慢性疼痛的患者会抱怨感觉异常多变，尤其是与姿势变化有关时。此类变化影响了绝大多数植入式脉冲发生器的患者，他们需要使用外部编程器来避免疼痛性感觉异常，甚至要断开发生器，从而导致疼痛缓解效果丧失。本研究的目的是确定刺激所需的脉冲电荷量与患者不同姿势之间的关系。
对70例接受脊髓刺激治疗的患者在以下姿势和情况下进行观察性研究：卧位、站立、坐位和行走。让患者站立时，我们分析了感觉阈值、疼痛阈值、疼痛缓解阈值以及治疗范围。对所有患者都进行了研究。之后，根据刺激器的解剖位置（颈部、胸部、骶部、枕部或皮下）对数据进行分析。
在对整个组的治疗范围分析中，我们发现卧位与站立位之间以及卧位与行走之间存在统计学上的显著差异。在胸椎水平，除站立与行走之间以及坐位与卧位之间外，所有位置之间均存在差异。在颈椎水平，未检测到显著差异。对脉冲电荷量的分析显示，卧位时存在显著差异，即达到满意刺激所需的电荷量较少。比较颈部和胸部水平植入电极时，站立位与坐位之间存在差异（P = 0.04），但卧位或行走与其他位置之间无差异。
目前刺激系统的设计无法适应电极与神经纤维之间距离的变化。在这方面需要改进。
