Reevaluation of the Role of the Sympathetic Nervous System in Cutaneous Vasodilation during Dorsal Spinal Cord Stimulation: Are Multiple Mechanisms Active?

An hypothesis is proposed which states that the characteristic hepatic changes seen after the administration of carbon tetrachloride are the result of stimulation of central sympathetic areas which produce a massive discharge of the peripheral sympathetic nervous system. Stimulation of the sympathetic supply to the blood vessels of the liver results in restriction of blood flow in the liver, leading to anoxia and the characteristic necrosis around the central vein of the hepatic lobule. Similarly the discharge causes the release of unesterified fatty acids from the peripheral fat depots and the consequent deposition of lipid in the liver. This hypothesis is based upon experimental evidence using the following physiologic and pharmacologic maneuvers: adrenergic blocking agents, pretreatment with reserpine, adrenalectomy and section of the spinal cord—all are effective to a greater or lesser extent in preventing the changes characteristically seen in oxidative phosphorylation of the liver mitochondria, activation of a Mg-dependent ATPase and deposition of lipid in the liver. Transection of the spinal cord is the most effective treatment and prevents entirely the characteristic changes seen in the above-mentioned functions.

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Electrochemical Skin Conductance Alterations during Spinal Cord Stimulation: An Experimental Study

Journal of Clinical Medicine ◽

10.3390/jcm10163565 ◽

2021 ◽

Vol 10 (16) ◽

pp. 3565

Author(s):

Lisa Goudman ◽

Nieke Vets ◽

Julie Jansen ◽

Ann De Smedt ◽

Maxime Billot ◽

...

Keyword(s):

Spinal Cord ◽

Nervous System ◽

Sympathetic Nervous System ◽

Skin Conductance ◽

Spinal Cord Stimulation ◽

Healthy Controls ◽

Sudomotor Function ◽

Skin Conductance Levels ◽

Sympathetic Nervous ◽

Age And Sex

Despite the well-known clinical effects of spinal cord stimulation (SCS), the mechanisms of action have not yet been fully unraveled. The primary aim of this study was to measure whether electrochemical skin conductance, as a measure of peripheral sympathetic autonomic function, is altered by SCS. A second aim was to compare skin conductance levels of patients with failed back surgery syndrome (FBSS) with age- and sex-matched healthy controls. Twenty-three patients with FBSS treated with SCS participated in this study. Sudomotor function was measured with the SudoscanTM instrument on the hands and feet during SCS on and off states. Difference scores in skin conductance between patients and age- and sex-matched healthy controls were calculated. Normal sudomotor function at the painful lower limb was revealed for 61% of the patients when SCS was activated. Skin conductance levels were not altered between on and off states of SCS. Differences in scores between patients and healthy controls were significantly different from zero. This study showed that SCS does not influencing the sympathetic nervous system in patients with FBSS, as measured by skin conductance levels. Moreover, it suggested that there is no normalization of the functioning of the sympathetic nervous system, despite the effectiveness of SCS to reduce pain intensity.

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Investigation of the function of the sympathetic nervous system in patients with failed back surgery syndrome, treated with spinal cord stimulation

Brain and Spine ◽

10.1016/j.bas.2021.100725 ◽

2021 ◽

Vol 1 ◽

pp. 100725

Author(s):

L. Goudman ◽

N. Vets ◽

J. Jansen ◽

A. De Smedt ◽

M. Moens

Keyword(s):

Spinal Cord ◽

Nervous System ◽

Sympathetic Nervous System ◽

Spinal Cord Stimulation ◽

Failed Back Surgery Syndrome ◽

Failed Back Surgery ◽

Back Surgery ◽

Sympathetic Nervous

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The role of sympathetic nervous system in the development of neurogenic pulmonary edema in spinal cord-injured rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.00574.2011 ◽

2012 ◽

Vol 112 (1) ◽

pp. 1-8 ◽

Cited By ~ 18

Author(s):

Jiří Šedý ◽

Josef Zicha ◽

Jara Nedvídková ◽

Jaroslav Kuneš

Keyword(s):

Blood Pressure ◽

Spinal Cord ◽

Nervous System ◽

Sympathetic Nervous System ◽

Neurogenic Pulmonary Edema ◽

Spinal Pathways ◽

Adrenoceptor Blocker ◽

Sympathetic Nervous ◽

Spinal Cord Injured

The pronounced activation of sympathetic nervous system is a necessary prerequisite for the development of neurogenic pulmonary edema (NPE) in rats with balloon compression of spinal cord. In this study we examined whether this is a consequence of rapid activation of spinal pathways leading to sympathetic venoconstriction, blood pressure rise, and reflex bradycardia. We found that NPE development can be prevented by epidural upper thoracic anesthesia or by transection of the upper spinal cord. This indicates an important role of spinal pathways activation. NPE development can also be prevented by moderate blood loss, supporting the role of blood redistribution to pulmonary circulation. In rats developing NPE the catecholamine surge following spinal cord compression involved not only a dramatic increase of circulating norepinephrine but also of epinephrine levels. The pretreatment of rats with α-1 adrenoceptor blocker prazosin, α-2 adrenoceptor blocker yohimbine, or calcium channel blocker nifedipine prevented NPE development, whereas the effect of β-adrenoceptor blockade with propranolol was less convincing. In conclusion, considerable activation of thoracic spinal pathways, followed by marked catecholamine secretion, play a major role in the development of NPE in spinal cord-injured rats. Enhanced α-adrenergic nifedipine-sensitive vasoconstriction is responsible for observed blood pressure changes, subsequent baroreflex bradycardia, and blood volume redistribution, which represent major pathogenetic mechanisms of NPE development.

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Thyroid hormone-catecholamine interrelationships during exposure to cold

Acta Endocrinologica ◽

10.1530/acta.0.0970091 ◽

1981 ◽

Vol 97 (1) ◽

pp. 91-97 ◽

Cited By ~ 21

Author(s):

H. Storm ◽

C. van Hardeveld ◽

A. A. H. Kassenaar

Keyword(s):

Nervous System ◽

Plasma Concentration ◽

Thyroid Hormone ◽

Sympathetic Nervous System ◽

Plasma Levels ◽

Surgical Procedure ◽

Exposure To Cold ◽

Basal Plasma ◽

Sympathetic Nervous

Abstract. Basal plasma levels for adrenalin (A), noradrenalin (NA), l-triiodothyronine (T3), and l-thyroxine (T4) were determined in rats with a chronically inserted catheter. The experiments described in this report were started 3 days after the surgical procedure when T3 and T4 levels had returned to normal. Basal levels for the catecholamines were reached already 4 h after the operation. The T3/T4 ratio in plasma was significantly increased after 3, 7, and 14 days in rats kept at 4°C and the same holds for the iodide in the 24-h urine after 7 and 14 days at 4°C. The venous NA plasma concentration was increased 6- to 12-fold during the same period of exposure to cold, whereas the A concentration remained at the basal level. During infusion of NA at 23°C the T3/T4 ratio in plasma was significantly increased after 7 days compared to pair-fed controls, and the same holds for the iodide excretion in the 24-h urine. This paper presents further evidence for a role of the sympathetic nervous system on T4 metabolism in rats at resting conditions.

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