Calancie B, Needham-Shropshire B, Jacobs P, Willer K, Zych G, Green B A
Miami Project to Cure Paralysis, FL 33136.
Brain. 1994 Oct;117 ( Pt 5):1143-59. doi: 10.1093/brain/117.5.1143.
We investigated a pattern of involuntary lower extremity stepping-like movements which recently appeared in a subject with a 17-year history of neurologically incomplete injury to the cervical spinal cord. The movements were rhythmic, alternating and forceful, involved all muscles of the lower extremities and could be reliably evoked by lying the subject down (supine) and extending his hips. Once in this position, the movements continued spontaneously, in the absence of external sensory perturbations, with a step-cycle duration of approximately 3.5 s (0.3 Hz). This rate could be either increased or temporarily halted by specific sensory inputs. Anaesthetizing the subject's right hip joint, in which we found evidence of pathology, led to a marked attenuation of the stepping movements for a period of approximately 15 min. We believe that a combination of (i) preserved but limited supraspinal tonic facilitation, and (ii) abnormal, perhaps noxious afferent inflow from the subject's right hip to the spinal cord may underlie the appearance of this highly unusual and involuntary movement pattern. The striking similarity between the movement and EMG patterns in this subject and those described in many reports using the surgically reduced cat model suggests that we were witnessing the first well-defined example of a central rhythm generator for stepping in the adult human.
我们研究了一名有17年颈脊髓神经不完全损伤病史的受试者最近出现的一种下肢非自主的类似踏步的运动模式。这些运动有节奏、交替且有力，涉及下肢所有肌肉，可通过让受试者躺下（仰卧位）并伸展其髋部可靠地诱发。处于该体位后，运动在无外部感觉干扰的情况下自发持续，步周期持续时间约为3.5秒（0.3赫兹）。该速率可通过特定的感觉输入增加或暂时停止。对受试者右髋关节进行麻醉（我们在其中发现了病理证据），导致踏步运动在约15分钟内显著减弱。我们认为，（i）保留但有限的脊髓上紧张性易化，以及（ii）来自受试者右髋部至脊髓的异常（可能是有害的）传入性神经冲动，两者结合可能是这种高度异常的非自主运动模式出现的基础。该受试者的运动和肌电图模式与许多使用手术去大脑猫模型的报告中所描述的模式之间惊人的相似性表明，我们正在见证成人人类中第一个明确的踏步中枢节律发生器的例子。
