 |
Previous Article | Next Article 
The Journal of Neuroscience, May 1, 1998, 18(9):3443-3450
Mechanisms of Cortical Reorganization in Lower-Limb Amputees
Robert
Chen,
Brian
Corwell,
Zaneb
Yaseen,
Mark
Hallett, and
Leonardo G.
Cohen
Human Cortical Physiology Unit, National Institute of Neurological
Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
20892-1430
The human motor system undergoes reorganization after amputation,
but the site of motor reorganization and the mechanisms involved are
unknown. We studied the site and mechanisms of motor reorganization in
16 subjects with traumatic lower-limb amputation. Stimulation at
different levels in the CNS was used to determine the site of
reorganization. The mechanisms involved were evaluated by measuring the
thresholds for transcranial magnetic stimulation (TMS) and by testing
intracortical inhibition and facilitation. With TMS, the threshold for
muscle activation on the amputated side was lower than that of the
intact side, but with transcranial electrical stimulation there was no
difference in motor threshold between the two sides. TMS at the maximal
output of the stimulator activated a higher percentage of the motor
neuron pool (%MNP) on the amputated side than on the intact side. The
%MNP activated by spinal electrical stimulation was similar on the two
sides. Paired TMS study showed significantly less intracortical
inhibition on the amputated side. Our findings suggest that motor
reorganization after lower-limb amputation occurs predominately at the
cortical level. The mechanisms involved are likely to include reduction of GABAergic inhibition.
Key words:
amputation; motor reorganization; mechanisms of
plasticity; human; transcranial magnetic stimulation; motor cortex
Copyright © 1998 Society for Neuroscience 0270-6474/98/1893443-08$05.00/0
This article has been cited by other articles:

|
 |

|
 |
 
H. Kumru, M. Kofler, J. Valls-Sole, E. Portell, and J. Vidal
Brainstem Reflexes Are Enhanced Following Severe Spinal Cord Injury and Reduced by Continuous Intrathecal Baclofen
Neurorehabil Neural Repair,
November 1, 2009;
23(9):
921 - 927.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Mercier and A. Sirigu
Training With Virtual Visual Feedback to Alleviate Phantom Limb Pain
Neurorehabil Neural Repair,
July 1, 2009;
23(6):
587 - 594.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
C. D. Vargas, A. Aballea, E. C. Rodrigues, K. T. Reilly, C. Mercier, P. Petruzzo, J. M. Dubernard, and A. Sirigu
Re-emergence of hand-muscle representations in human motor cortex after hand allograft
PNAS,
April 28, 2009;
106(17):
7197 - 7202.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. C. Stoeckel, R. J. Seitz, and C. M. Buetefisch
Congenitally altered motor experience alters somatotopic organization of human primary motor cortex
PNAS,
February 17, 2009;
106(7):
2395 - 2400.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Z. J. Daskalakis, B. K. Christensen, P. B. Fitzgerald, and R. Chen
Dysfunctional Neural Plasticity in Patients With Schizophrenia
Arch Gen Psychiatry,
April 1, 2008;
65(4):
378 - 385.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y.-Z. Huang, J. C. Rothwell, M. J. Edwards, and R.-S. Chen
Effect of Physiological Activity on an NMDA-Dependent Form of Cortical Plasticity in Human
Cereb Cortex,
March 1, 2008;
18(3):
563 - 570.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. P. Lefaucheur, X. Drouot, I. Menard-Lefaucheur, Y. Keravel, and J. P. Nguyen
Motor cortex rTMS restores defective intracortical inhibition in chronic neuropathic pain.
Neurology,
November 14, 2006;
67(9):
1568 - 1574.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Mercier, K. T. Reilly, C. D. Vargas, A. Aballea, and A. Sirigu
Mapping phantom movement representations in the motor cortex of amputees
Brain,
August 1, 2006;
129(8):
2202 - 2210.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Bretzner and T. Drew
Changes in Corticospinal Efficacy Contribute to the Locomotor Plasticity Observed After Unilateral Cutaneous Denervation of the Hindpaw in the Cat
J Neurophysiol,
October 1, 2005;
94(4):
2911 - 2927.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. Alkadhi, P. Brugger, S. H. Boendermaker, G. Crelier, A. Curt, M.-C. Hepp-Reymond, and S. S. Kollias
What Disconnection Tells about Motor Imagery: Evidence from Paraplegic Patients
Cereb Cortex,
February 1, 2005;
15(2):
131 - 140.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Sharshar, E. T. Ross, N. S. Hopkinson, R. Porcher, A. H. Nickol, S. Jonville, M. J. Dayer, N. Hart, J. Moxham, F. Lofaso, et al.
Depression of diaphragm motor cortex excitability during mechanical ventilation
J Appl Physiol,
July 1, 2004;
97(1):
3 - 10.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. M. Butefisch
Plasticity in the Human Cerebral Cortex: Lessons from the Normal Brain and from Stroke
Neuroscientist,
April 1, 2004;
10(2):
163 - 173.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
K. R. Huxlin and T. Pasternak
Training-induced Recovery of Visual Motion Perception after Extrastriate Cortical Damage in the Adult Cat
Cereb Cortex,
January 1, 2004;
14(1):
81 - 90.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. Schwenkreis, F. Janssen, O. Rommel, B. Pleger, B. Volker, I. Hosbach, R. Dertwinkel, C. Maier, and M. Tegenthoff
Bilateral motor cortex disinhibition in complex regional pain syndrome (CRPS) type I of the hand
Neurology,
August 26, 2003;
61(4):
515 - 519.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Z. J. Daskalakis, B. K. Christensen, P. B. Fitzgerald, and R. Chen
Transcranial Magnetic Stimulation: A New Investigational and Treatment Tool in Psychiatry
J Neuropsychiatry Clin Neurosci,
November 1, 2002;
14(4):
406 - 415.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Sailer, G. F Molnar, D. I Cunic, and R. Chen
Effects of peripheral sensory input on cortical inhibition in humans
J. Physiol.,
October 15, 2002;
544(2):
617 - 629.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Stefan, E. Kunesch, R. Benecke, L. G Cohen, and J. Classen
Mechanisms of enhancement of human motor cortex excitability induced by interventional paired associative stimulation
J. Physiol.,
September 1, 2002;
543(2):
699 - 708.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. J. Werhahn, J. Mortensen, A. Kaelin-Lang, B. Boroojerdi, and L. G. Cohen
Cortical excitability changes induced by deafferentation of the contralateral hemisphere
Brain,
June 1, 2002;
125(6):
1402 - 1413.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P A McNulty, V G Macefield, J L Taylor, and M Hallett
Cortically evoked neural volleys to the human hand are increased during ischaemic block of the forearm
J. Physiol.,
January 1, 2002;
538(1):
279 - 288.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M C Ridding and J L Taylor
Mechanisms of motor-evoked potential facilitation following prolonged dual peripheral and central stimulation in humans
J. Physiol.,
December 1, 2001;
537(2):
623 - 631.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Karl, N. Birbaumer, W. Lutzenberger, L. G. Cohen, and H. Flor
Reorganization of Motor and Somatosensory Cortex in Upper Extremity Amputees with Phantom Limb Pain
J. Neurosci.,
May 15, 2001;
21(10):
3609 - 3618.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. D Sanger, R. R Garg, and R. Chen
Interactions between two different inhibitory systems in the human motor cortex
J. Physiol.,
January 15, 2001;
530(2):
307 - 317.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. G Cohen
A window into the role of inhibitory and excitatory mechanisms of perception?
J. Physiol.,
December 1, 2000;
529(2):
283 - 283.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H.-X. Qi, I. Stepniewska, and J. H. Kaas
Reorganization of Primary Motor Cortex in Adult Macaque Monkeys With Long-Standing Amputations
J Neurophysiol,
October 1, 2000;
84(4):
2133 - 2147.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. H. Schieber
New Views of the Primary Motor Cortex
Neuroscientist,
October 1, 2000;
6(5):
380 - 389.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Chen and R. Garg
Facilitatory I Wave Interaction in Proximal Arm and Lower Limb Muscle Representations of the Human Motor Cortex
J Neurophysiol,
March 1, 2000;
83(3):
1426 - 1434.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Hallett
{blacksquare} REVIEW : Plasticity in the Human Motor System
Neuroscientist,
September 1, 1999;
5(5):
324 - 332.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
P A McNulty, V G Macefield, J L Taylor, and M Hallett
Cortically evoked neural volleys to the human hand are increased during ischaemic block of the forearm
J. Physiol.,
January 1, 2002;
538(1):
279 - 288.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|