Changing central nervous system control following intercostal nerve transfer.
OBJECTIVE
The goal of this study was to find which central nervous system (CNS) pathways are involved in volitional control over reinnervated biceps or pectoral muscles.


METHODS
Intercostal nerves (ICNs) were coapted to the musculocutaneous nerve (MCN) or the medial pectoral nerve (MPN) in 23 patients with root avulsions of the brachial plexus to restore biceps or pectoral muscle function. The facilitatory effects of respiration and voluntary contraction on cortical motor-evoked potentials of biceps or pectoral muscles were used to study CNS control over the reinnervated muscles. The time course of the facilitatory effect of respiration and voluntary contraction differed significantly. In the end stage of nerve regeneration, the facilitatory effect of voluntary contraction was significantly larger than that of respiration, indicating that the CNS control network over the muscle comes to resemble that of the recipient nerve (MCN or MPN) rather than that of the donor nerve (ICN).


CONCLUSIONS
The strengthening of previously subthreshold synaptic connections in a CNS network connecting ICN to MCN or MPN neurons may underlie changing excitability.
Malessy
M J
MJ
Department of Neurosurgery, Leiden University Medical Center, The Netherlands. lesnik_malessy@dataweb.nl
Thomeer
R T
RT
van Dijk
J G
JG
D000328:Adult; D001917:Brachial Plexus / Q000293:injuries / Q000601:surgery; D001921:Brain / Q000502:physiology*; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D007367:Intercostal Nerves / Q000601:surgery*; D008280:Magnetics; D008297:Male; D015999:Multivariate Analysis; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation* / Q000601:surgery; D009138:Musculocutaneous Nerve / Q000601:surgery; D009416:Nerve Regeneration / Q000502:physiology; D016067:Nerve Transfer / Q000379:methods*; D009431:Neural Conduction / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000502:physiology; D010369:Pectoralis Muscles / Q000294:innervation* / Q000601:surgery; D011446:Prospective Studies; D012119:Respiration / Q000502:physiology; D013569:Synapses / Q000502:physiology