Effects of nigral stimulation on locomotion and postural stability in patients with Parkinsons disease
Effects of nigral stimulation on locomotion and postural stability in patients with Parkinsons disease
复制标题
DOI：
10.1093/brain/awn294
复制
发表时间：
2009-01-01
期刊：
影响因子：
14.5
通讯作者：
Welter, M. L.
中科院分区：
文献类型：
--
作者：
Chastan, N.;Westby, G. W. M.;Welter, M. L.
帕金森病患者步态和平衡障碍的病理生理机制仍然知之甚少。左旋多巴治疗和丘脑底核（STN）刺激可改善步长和步行速度，对姿势不稳定的影响较小。这些疾病与下行基底神经节输出到脑干结构的功能障碍有关。在这项研究中，我们评估了刺激黑质网状部（SNr）对帕金森病患者运动和平衡的影响。在204例接受刺激的患者中，7例接受双侧延髓刺激的选定患者在步态启动期间记录生物力学参数和腿部肌肉活动，每个电极的一个触点位于SNr内。步长，前后和垂直速度的重心进行了研究，特别是参考的科目的能力，刹车的重心下降之前，脚接触，并进行了比较，七个控制。在帕金森病患者中，测试了五种治疗条件：（i）无治疗，（ii）左旋多巴治疗，（iii）STN刺激，（iv）SNr刺激和（v）左旋多巴治疗和STN刺激的组合。这些治疗对运动性帕金森病残疾的影响采用WARNRS III量表进行评估，分为轴向（从椅子上站起来，姿势，姿势稳定性和步态）和远端评分。而左旋多巴和/或SNr刺激改善了轴向和远端运动症状，SNr刺激仅改善了轴向症状。与对照组相比，未经治疗的帕金森病患者显示步长和速度减少，脚接触前制动不良，比目鱼肌（S）和胫骨前肌（AT）肌肉活动减少。在自然和快速步态条件下，单独使用左旋多巴治疗或与电刺激联合使用，以及在快速步态条件下单独使用电刺激，步长和速度显著增加。相反，SNr刺激在任何条件下对这些措施都没有显着影响。在自然步态条件下，由于步长较小，无需主动制动，因此不会发生重心下降。在快速步态的条件下，制动改善与电刺激或SNr，但不是与左旋多巴治疗，在站立腿S肌肉活动的增加。这些结果表明，前后（长度和速度）和垂直（制动能力）步态参数控制由两个不同的系统内的基底神经节电路，分别代表运动和平衡。SNr是已知投射到桥脑中脑结构的主要基底神经节输出，被假定为特别涉及步态期间的平衡控制。
The physiopathology of gait and balance disorders in Parkinsons disease patients is still poorly understood. Levodopa treatment and subthalamic nucleus (STN) stimulation improve step length and walking speed, with less effect on postural instability. These disorders have been linked to dysfunction of the descending basal ganglia outputs to brainstem structures. In this study, we evaluated the effects of stimulation of the substantia nigra pars reticulata (SNr), on locomotion and balance in Parkinsons disease patients. Biomechanical parameters and leg muscle activity were recorded during gait initiation in seven selected patients operated for bilateral STN stimulation, out of 204 stimulated patients, with one contact of each electrode located within the SNr. Step length, anteroposterior and vertical velocities of the centre of gravity were studied, with special reference to the subjects ability to brake the centre of gravity fall before foot-contact, and compared to seven controls. In Parkinsons disease patients, five treatment conditions were tested: (i) no treatment, (ii) levodopa treatment, (iii) STN stimulation, (iv) SNr stimulation and (v) combined levodopa treatment and STN stimulation. The effects of these treatments on motor parkinsonian disability were assessed with the UPDRS III scale, separated into axial (rising from chair, posture, postural stability and gait) and distal scores. Whereas levodopa and/or STN stimulation improved axial and distal motor symptoms, SNr stimulation improved only the axial symptoms. Compared to controls, untreated Parkinsons disease patients showed reduced step length and velocity, and poor braking just prior to foot-contact, with a decrease in both soleus (S) and anterior tibialis (AT) muscle activity. Step length and velocity significantly increased with levodopa treatment alone or in combination with STN stimulation in both natural and fast gait conditions, and with STN stimulation alone in the fast gait condition. Conversely, SNr stimulation had no significant effect on these measures in either condition. In the natural gait condition, no fall in the centre of gravity occurred as step length was low and active braking was unnecessary. In the fast gait condition, braking was improved with STN or SNr stimulation but not with levodopa treatment, with an increase in the stance leg S muscle activity. These results suggest that anteroposterior (length and velocity) and vertical (braking capacity) gait parameters are controlled by two distinct systems within the basal ganglia circuitry, representing respectively locomotion and balance. The SNr, a major basal ganglia output known to project to pontomesencephalic structures, is postulated as being particularly involved in balance control during gait.