Stimulation of the Spinal Cord by Placement of Surgical-Based Paddle Leads

Author(s):  
Shivanand P. Lad ◽  
Erika Petersen ◽  
Andrew Marky ◽  
Timothy R. Deer ◽  
Robert M. Levy ◽  
...  
Keyword(s):  
2008 ◽  
Vol 38 (7) ◽  
pp. 695-701 ◽  
Author(s):  
I. Yu. Dorofeev ◽  
V. D. Avelev ◽  
N. A. Shcherbakova ◽  
Yu. P. Gerasimenko

2005 ◽  
Vol 102 (3) ◽  
pp. 624-632 ◽  
Author(s):  
Steven L. Jinks ◽  
Carmen L. Dominguez ◽  
Joseph F. Antognini

Background Individuals with spinal cord injury may undergo multiple surgical procedures; however, it is not clear how spinal cord injury affects anesthetic requirements and movement force under anesthesia during both acute and chronic stages of the injury. Methods The authors determined the isoflurane minimum alveolar concentration (MAC) necessary to block movement in response to supramaximal noxious stimulation, as well as tail-flick and hind paw withdrawal latencies, before and up to 28 days after thoracic spinal transection. Tail-flick and hind paw withdrawal latencies were measured in the awake state to test for the presence of spinal shock or hyperreflexia. The authors measured limb forces elicited by noxious mechanical stimulation of a paw or the tail at 28 days after transection. Limb force experiments were also conducted in other animals that received a reversible spinal conduction block by cooling the spinal cord at the level of the eighth thoracic vertebra. Results A large decrease in MAC (to </= 40% of pretransection values) occurred after spinal transection, with partial recovery (to approximately 60% of control) at 14-28 days after transection. Awake tail-flick and hind paw withdrawal latencies were facilitated or unchanged, whereas reflex latencies under isoflurane were depressed or absent. However, at 80-90% of MAC, noxious stimulation of the hind paw elicited ipsilateral limb withdrawals in all animals. Hind limb forces were reduced (by >/= 90%) in both chronic and acute cold-block spinal animals. Conclusions The immobilizing potency of isoflurane increases substantially after spinal transection, despite the absence of a baseline motor depression, or "spinal shock." Therefore, isoflurane MAC is determined by a spinal depressant action, possibly counteracted by a supraspinal facilitatory action. The partial recovery in MAC at later time points suggests that neuronal plasticity after spinal cord injury influences anesthetic requirements.


1981 ◽  
Vol 44 (4) ◽  
pp. 207-217 ◽  
Author(s):  
Don M. Long ◽  
Donald Erickson ◽  
James Campbell ◽  
Richard North

1958 ◽  
Vol 16 (3) ◽  
pp. 237-260 ◽  
Author(s):  
B. A. CROSS

SUMMARY The spontaneous motility of the intact uterus of spayed oestrogenized rabbits under sodium pentobarbitone anaesthesia has been recorded. Both uteri of each animal behaved similarly, and contractions often appeared to be synchronous. Small changes of load affected the amplitude of contractions, but did not alter uterine responsiveness to neurohypophysial or adrenomedullary hormones. Mid-thoracic section of the spinal cord obliterated spontaneous motility of the uterus; spinal anaesthesia did not. Spontaneous motility persisted for as long as 7 hr after decerebration and removal of the pituitary gland. The threshold dose of oxytocin for activating the oestrogenized uterus was the same as that for the lactating mammary gland, i.e. 1–5 mu. Doses up to 50 mu. usually gave an increase in frequency and amplitude of contractions. In the same dose range vasopressin either had little effect or inhibited spontaneous uterine motility, although milk ejection was stimulated. Slow infusion of oxytocin at rates of 1·5–48 mu./min produced graded increases in the rate and depth of uterine contractions and, at the same time, in similarly treated, lactating animals, rhythmic milk-ejection responses which at the higher rates of infusion merged to give a tetanic (plateau) type of milk ejection. Adrenaline or noradrenaline in doses of 1–5 μg produced diphasic uterine responses, initial contractions being followed by inhibition of spontaneous motility. They also inhibited the uterine, as well as the milk-ejection response to oxytocin injected 10–30 sec later. The inhibitory effect of adrenaline on both organs was about twice that of noradrenaline. The above-mentioned responses to adrenaline and oxytocin could also be elicited by electrical stimulation of the hypothalamus. Stimuli in the dorsal, lateral, perifornical and posterior hypothalamic areas produced effects equivalent to those of 1–5 μg adrenaline on both the uterus and mammary gland. These responses were abolished by mid-thoracic section of the spinal cord or by spinal anaesthesia. In such preparations responses typical of those produced by oxytocin were seen in both organs after stimulation of the paraventricular nuclei, supraoptic nuclei and the hypothalamo-hypophysial nerve pathways of the tuber cinereum and neural stalk. Dilatation of the vagina (or rectum) gave rise to a uterine response similar to that resulting from adrenaline or noradrenaline. The response was abolished by spinal anaesthesia, but not by mid-thoracic spinal section or decerebration. The same stimuli also produced 'bearing down' contractions of the abdominal muscles. Contractions of the uterus could also be elicited by mechanical stimuli, in the absence of functional spinal connexions.


Sign in / Sign up

Export Citation Format

Share Document