"sympathicotomy may cause a temporary impairment of the caudal-to-rostral hierarchy of thermoregulatory control and changes in microcirculation"

Patients with palmar hyperhidrosis have been reported to have a much
more complex dysfunction of autonomic nervous system, involving compensatory high parasympathetic activity as well as sympathetic overactivity (13, 14), suggesting that sympathicotomy initially induces a sympathovagal imbalance with a parasympathetic predominance, and that this is restored on a long-term basis (14). Therefore, thoracic sympathicotomy may cause a temporary impairment of the caudal-to-rostral hierarchy of thermoregulatory control and changes in microcirculation.

The reduction of finger skin temperature on the non-denervated side may be due to either a decrease in the cross-
inhibitory effect or the abnormal control of the inhibitory fibers by the sudomotor center (6).
Vasoconstrictor neurons have been found to be largely under the inhibitory control of various afferent
input systems from the body surface, whereas sudomotor neurons are predominantly under excitatory
control (15). The basic neuronal network for this reciprocal organization is probably located in the spinal level (15). Therefore, the reduction in the contralateral skin temperature may be explained by cross-inhibitory control of various afferent in the spinal cord.
In particular, our study showed that, following bilateral T3 sympathicotomy, the skin temperatures on
the hands increased whereas the skin temperatures on the feet decreased. These findings suggest a
cross-inhibitory control between the upper and lower extremities. However, the pattern of skin
temperature reduction on the feet differed from that on the contralateral hand. The skin temperature on
the feet did not decrease after right T3 sympathicotomy but decreased significantly after bilateral T3
sympathicotomy.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722005/

sympathectomy, although having varying results, does seem to increase the severity of autoimmune disorders

Allostasis - a state of imbalance responsible for Autoimmune disorders

In general, enhancing the sympathetic tone decreases both T0-cell and NK cell functions but not the proliferation of splenic B cells (Dowdell and Whitacre, 2000). In contrast, chemical sympathectomy, although having varying results, does seem to increase the severity of autoimmune disorders (Dowdell and Whitacre, 2000)
As far as metabolism, catecholamines promote mobilization of fuel stores at time of stress and act synergistically with glucocorticoids to increased glycogenolysis, gluconeogenesis, and lipolysis but exert opposing effects of protein catabolism, as noted earlier. One important aspect is regulation of body temperature (Goldsttein and Eisenhofer, 2000) Epinephrine levels are also positively related to serum levels of HDL cholesterol and negatively related to triglycerines. However, perturbing the balance of activity of various mediators or metabolism and body weight regulation can lead to well-known metabolic disorders such as type 2 diabetes and obesity.

At the same time, increased sympathetic activitation and nerephinephrine release is elevated in hypertensive individuals and also higher levels of insulin, and there are indications that insulin further increases sympathetic activity in a vicious cycle (Arauz-Pacheco et al.,1996)

As a result of either local production, cytokines often enter the the circultion and can be detected in plasma samples. Sleep deprivation and psychological stress, such as public speaking, are reported to elevate inflammatory cytokine level in blood (Altemus et al., 2001) Circulting levels of a number of inflammatory cytokines are elevated in relation to viral and other infections and contirbute to the feeling of being sick, as well as sleepiness, wiht both direct and indirect effects on the central nervous system (Arkins et al., 2000; Obal and Kueger, 2000)

Inflammatory autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis, and type 1 diabetes, reflect an allostatic state that consists of at least three principal causes: genetic risk factors, (...) factors that contribute to the development of tolerance of self-antigens (...) and the hormonal mikieu that regulates adaptive immunes responses (Dowdell and Whitacre, 2000)

Allostasis, homeostasis and the costs of physiological adaptation

By Jay SchulkinCambridge University Press, 2004

Allostasis is the process of achieving stability, or homeostasis, through physiological or behavioral change. This can be carried out by means of alteration in HPA axishormones, the autonomic nervous system, cytokines, or a number of other systems, and is generally adaptive in the short term ^[1]

"Similar low values are observed in patients with sympathectomy and in patients with tetraplegia"

"Patients with progressive autonomic dysfunction (including diabetes) have little or no increase in plasma noradrenaline and this correlates with their orthostatic intolerance (Bannister, Sever and Gross, 1977). In patients with pure autonomic failure, basal levels of noradrenaline are lower than in normal subjects (Polinsky, 1988). Similar low values are observed in patients with sympathectomy and in patients with tetraplegia. (p.51)



The finger wrinkling response is abolished by upper thoracic sympathectomy. The test is also abnormal in some patients with diabetic autonomic dysfunction, the Guillan-Barre syndrome and other peripheral sympathetic dysfunction in limbs. (p.46)

Other causes of autonomic dysfunction without neurological signs include medications, acute autonomic failure, endocrine disease, surgical sympathectomy . (p.100) 




Anhidrosis is the usual effect of destruction of sympathetic supply to the face. However about 35% of patients with sympathetic devervation of the face, acessory fibres (reaching the face through the trigeminal system) become hyperactive and hyperhidrosis occurs, occasionally causing the interesting phenomenon of alternating hyperhidrosis and Horner's Syndrome (Ottomo and Heimburger, 1980). (p.159)



Disorders of the Autonomic Nervous System
By David Robertson, Italo Biaggioni
Edition: illustrated
Published by Informa Health Care, 1995
ISBN 3718651467, 9783718651467"

sympathectomy severs both vasomotor and sensory fibres

CUTANEOUS INNERVATION IN MAN BEFORE AND AFTER LUMBAR SYMPATHECTOMY:EVIDENCE FOR INTERRUPTION OF BOTH SENSORY AND VASOMOTOR NERVE FIBRES. 

ORIGINAL ARTICLES

ANZ Journal of Surgery. 73(1-2):14-18, January 2003.
COVENTRY, BRENDON J. BM BS, PhD, FRACS *; WALSH, JOHN A. MD, FRACS +

Abstract:
Background: Rest pain and severe ischaemia in patients who are unable to be offered (further) surgery to revascularize the lower limb is still problematic. Lumbar sympathectomy has been used for many years but the mechanisms by which this works are not absolutely clear. Both sensory and vasomotor fibres travel in the lumbar sympathetic chain and the effects of lumbar sympathectomy on these nerve types have been investigated in the present paper.

Methods: Immunohistochemical methods were used to detect neuropeptides contained in sensory and vasomotor nerves in the lower limb skin of (i) patients having amputations for peripheral vascular disease (PVD) after previous (chemical or surgical) sympathectomy; (ii) patients having amputations for PVD without previous (chemical or surgical) sympathectomy; and in control normal skin. The three groups are compared and the results are discussed.

Results: Normal and PVD controls had intact sensory and vasomotor nerves around dermal cutaneous blood vessels, but these were completely or virtually completely lost after lumbar sympathectomy, by either chemical or surgical means.

Conclusions: Lumbar sympathectomy severs both vasomotor and sensory fibres, suggesting that relief of rest pain may be explained not only by increased cutaneous and muscle blood flow, but also by nociceptive sensory denervation.

"Sympathectomy is a destructive procedure that interrupts the sympathetic nervous system"

Cervico-thoracic or lumbar sympathectomy for neuropathic pain | Cochrane Summaries: "Sympathectomy is a destructive procedure that interrupts the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy sympathetic nervous tissue (the so-called "sympathetic chain" of nerve ganglia). Surgical ablation can be performed by open removal or electrocoagulation (destruction of tissue with high-frequency electrical current) of the sympathetic chain, or by minimally invasive procedures using thermal or laser interruption. Nerve regeneration commonly occurs following both surgical or chemical ablation, but may take longer with surgical ablation.

This systematic review found only one small study (20 participants) of good methodological quality, which reported no significant difference between surgical and chemical sympathectomy for relieving neuropathic pain. Potentially serious complications of sympathectomy are well documented in the literature, and one (neuralgia) occurred in this study.

The practice of sympathectomy for treating neuropathic pain is based on very weak evidence. Furthermore, complications of the procedure may be significant."



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Many injuries to the nervous system are followed by incomplete recovery or even increasing disability over time

Many injuries to the nervous system are followed by incomplete recovery or even increasing disability over time. Some of these long term effects are due to the loss of access to growth factors called neurotrophins that provide essential support for adult nerve cells. We recently discovered that immune responses can be triggered by injury leading to inflammation around the damaged nerve cells. Control of inflammation may therefore allow the remaining nerve cells to survive until treatments that enable them to regenerate can be developed.

http://www.neura.edu.au/health/nerve-and-spinal-cord-injury

24-hour melatonin measurements in normal subjects and after peripheral sympathectomy

J Clin Endocrinol Metab. 1991 Apr;72(4):819-23.

Sequential cerebrospinal fluid and plasma sampling in humans: 24-hour melatonin measurements in normal subjects and after peripheral sympathectomy.

Bruce J1, Tamarkin L, Riedel C, Markey S, Oldfield E.

Author information

Abstract

Simultaneous measurements of plasma and cerebrospinal fluid (CSF) melatonin and urinary excretion of 6-hydroxymelatonin were performed in four normal volunteers and one patient before and after upper thoracic sympathectomy for the control of essential hyperhidrosis. For normal individuals, hourly 24-h melatonin concentrations in plasma and CSF exhibited similar profiles, with low levels during the day and high levels at night. Peak plasma levels varied from 122-660 pmol/L, and the peak CSF levels from 94-355 pmol/L. The onset of the nocturnal increase in melatonin did not occur at the same time for each individual. Urinary 6-hydroxymelatonin levels also exhibited a daily rhythm, with peak excretion at night. The individual with the lowest nocturnal levels of circulating melatonin also had the lowest excretion of 6-hydroxymelatonin. In the patient with hyperhidrosis, a prominent melatonin rhythm was observed preoperatively in the CSF and plasma. After bilateral T1-T2 ganglionectomy, however, melatonin levels were markedly reduced, and the diurnal rhythm was abolished. These results provide direct evidence in humans for a diurnal melatonin rhythm in CSF and plasma as well as regulation of this rhythm by sympathetic innervation.

http://www.ncbi.nlm.nih.gov/pubmed/2005207