TY - JOUR
T1 - Involuntary stepping after chronic spinal cord injury
T2 - Evidence for a central rhythm generator for locomotion in man
AU - Calancie, Blair
AU - Needham-shropshire, Belinda
AU - Jacobs, Patrick
AU - Willer, Keith
AU - Zych, Gregory
AU - Green, Barth A.
N1 - Funding Information:
Bunge and Keir Pearson regarding the organization of this manuscript are gratefully acknowledged and special thanks are due to our research subject, who endured many hours of experimentation with extraordinary patience and good humour. This work was supported in part by NIH grant NS 28059-01 (B. Calancie) and by The Miami Project to Cure Paralysis.
PY - 1994/10
Y1 - 1994/10
N2 - 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 ~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 ~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.
AB - 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 ~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 ~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.
KW - Central rhythm generator
KW - Locomotion
KW - Spinal cord injury
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U2 - 10.1093/brain/117.5.1143
DO - 10.1093/brain/117.5.1143
M3 - Article
C2 - 7953595
AN - SCOPUS:0027994873
VL - 117
SP - 1143
EP - 1159
JO - Brain
JF - Brain
SN - 0006-8950
IS - 5
ER -