Importance of bilateral sympathetic innervation on cerebral blood flow autoregulation in the thalamus

Brain Res. 1987 Jun 16;413(2):297-301.

Effects of bilateral sympathetic innervation on the regulation of cerebral blood flow to the thalamus were examined in spontaneously hypertensive rats (SHR). The superior cervical ganglion was removed on one side or bilaterally, and blood flow in the thalamus was repeatedly measured with a hydrogen clearance technique during a stepwise increase in arterial pressure. Sympathectomy on one side neither had effects on the pressure-flow relationship nor on the blood pressure levels of upper limits of autoregulation in the ipsilateral thalamus. In contrast, bilateral sympathetic denervation impaired the autoregulatory function in the thalamus and the upper limits were significantly lower than those in intact rats: 206 +/- 8 vs 226 +/- 10 mm Hg, respectively (P less than 0.02).
PMID: 3607478 [PubMed - indexed for MEDLINE]

effect of electric stimulation of the sympathetic cord in the upper thoracic level on the middle cerebral artery blood flow

Source: CEREBROVASCULAR DISEASES Volume: 2 Issue: 6 Pages: 359-364 Published: NOV-DEC

1992
Times Cited: 20 References: 41
Abstract: The effect of electric stimulation of the sympathetic cord in the upper thoracic level on the middle cerebral artery blood flow veloCitY (V(MCA)) in humans was examined using transcranial Doppler sonography monitoring during surgery for palmar hyperhidrosis.
Sympathetic stimulation resulted in marked and rapid increases Of V(MCA). The responses were preceded by prompt increases of mean arterial blood pressure (MABP) and heart rate (HR).
Division of the sympathetic cord cranially or caudally to the stimulation site partially reduced the V(MCA), MABP and HR responses. Both these operations reduced sympathetic pathways to the heart as reflected by a decrease in HR and MABP. The integrity of the sympathetic pathway from the stimulation site through the superior cervical ganglion and the carotid plexus was not a prerequisite for a V(MCA) response. Our data suggest that the V(MCA) increase mainly results from stimulation of the heart and the cardiovascular system, resulting in marked increases of blood
pressure and heart rate.

Cervical sympathectomy and cerebral microvascular and blood flow responses to hypocapnic hypoxia

The number of perfused arterioles and capillaries was significantly higher under hypoxic conditions than under normoxic conditions in sham and ganglionectomized animals. During hypoxia, the percent of arterioles per squared millimeter perfused increased to 63 +/- 5% in sham-lesioned rats and to a significantly greater extent, 80 +/- 6%, in ganglionectomized rats. The percentage of capillaries per squared millimeter perfused changed similarly. The peripheral sympathetic nervous system appeared to play an important role in the control of cerebral microvascular response to hypoxia.

Am J Physiol Heart Circ Physiol 256: H460-H467, 1989;

http://ajpheart.physiology.org/cgi/content/abstract/256/2/H460

Autonomic neural control of cerebral hemodynamics

In patients with sympathetic failure, the orthostatic reduction in cerebral blood velocity and oxygenation is larger.

In patients with sympathetic failure, the orthostatic reduction in cerebral blood velocity and oxygenation is larger. Patients who become symptomatic within 5 minutes of standing are characterized by a pronounced orthostatic fall in blood pressure, cerebral blood velocity, and oxygenation manifest within the first 10 seconds of standing.
Stroke. 2000;31:1608-1614

Increased cerebral vasoconstriction or reduced vasomotion also may attenuate CBFV variability

Altered cerebral hemodynamics in early Alzheimer disease: a pilot study using transcranial Doppler.

J Alzheimers Dis. 2009 Jul;17(3):621-9.

Autonomic neural control of cerebral hemodynamics

it has been found that in humans CBFV in the middle cerebral artery decreased substantially during
lower body negative pressure (LBNP) and head-up tilt in the absence of systemic hypotension, which suggests the presence of cerebral vasoconstriction associated with augmented sympathetic nerve activity during orthostatic stress.
IEEE Eng Med Biol Mag. 2009 Nov-Dec;28(6):54-62.

SYMPATHETIC-NERVE STIMULATION IN HUMANS INCREASES MIDDLE CEREBRAL-ARTERY BLOOD-FLOW VELOCITY

The effect of electric stimulation of the sympathetic cord in the upper thoracic level on the middle cerebral artery blood flow veloCitY (V(MCA)) in humans was examined using transcranial Doppler sonography monitoring during surgery for palmar hyperhidrosis. Sympathetic stimulation resulted in marked and rapid increases Of V(MCA). The responses were preceded by prompt increases of mean arterial blood pressure (MABP) and heart rate (HR). Division of the sympathetic cord cranially or caudally to the stimulation site partially reduced the V(MCA), MABP and HR responses. Both these operations reduced sympathetic pathways to the heart as reflected by a decrease in HR and MABP. The integrity of the sympathetic pathway from the stimulation site through the superior cervical ganglion and the carotid plexus was not a prerequisite for a V(MCA) response. Our data suggest that the V(MCA) increase mainly results from stimulation of the heart and the cardiovascular system, resulting in marked increases of blood pressure and heart rate.

CEREBROVASCULAR DISEASES Volume: 2 Issue: 6 Pages: 359-364 Published: NOV-DEC 1992

ETS suppresses the activation of the sympathetic nervous system slightly, similar to beta-blocker therapy

On the 123I-MIBG imaging studies, the early H/M ratio before EUTS was 2.35 ± 0.26 and postoperatively it was 2.29 ± 0.23. The delayed H/M ratio before EUTS was 2.59 ± 0.3 and after the procedure it was 2.66 ± 0.27. There was no significant difference between the H/M ratio before and after EUTS. The washout rate after EUTS (14.27 ± 4.71%) was significantly lower than that measured before EUTS (18.36 ± 5.13%; p < 0.01).

Endoscopic upper thoracic sympathectomy is a minimally invasive procedure; no local denervation was found after EUTS. Findings on 123I-MIBG imaging studies indicate that EUTS suppresses the activation of the sympathetic nervous system slightly, similar to beta-blocker therapy.

Journal of Neurosurgery March 2004 Volume 100, Number 3

a significant decrease in heart rate and ejection fraction, a significant decrease of ‘rest’ and ‘peak’ heart rate

In pulmonary function tests, we found a statistically significant decrease forced expiratory flow in small airways and an increase of residual volume, a significant decrease in heart rate and ejection fraction, a significant decrease of ‘rest’ and ‘peak’ heart rate, and a significant increase of oxygen pulse (O2 pulse) and oxygen peak uptake ( peak) after ETS (p < 0.05).

Eur J Cardiothorac Surg 2009;36:491-496. doi:10.1016/j.ejcts.2009.03.059

Significant reductions in maximal heart rate (HR) and oxygen and carbon dioxide uptakes were observed

The maximal midexpiratory flow was the only variable that showed significant changes, from 101% (SD, 26%) to 92% (SD, 27%) [p < 0.05]. Ten patients had positive bronchial challenge test results that remained positive 3 months after surgery, and 2 patients whose challenge test results were negative before surgery became positive after sympathectomy. Significant reductions in maximal heart rate (HR) and oxygen and carbon dioxide uptakes were observed during the maximal exercise test.
Chest. 2005 Oct;128(4):2702-5.

Changes in hemodynamics of the carotid and middle cerebral arteries before and after endoscopic sympathectomy in patients with palmar hyperhidrosis

Patients who underwent T-2 sympathectomy demonstrated a significant increase in blood flow volume and flow velocities of the CAs and MCA, especially on the left side. Asymmetry of sympathetic influence on the hemodynamics of the CAs and MCA was noted. The usefulness of sympathectomy for the treatment of ischemic cardiovascular and cerebrovascular disease deserves further investigation.
Journal on Neurosurgery March 1999 Volume 90, Number 3

http://thejns.org/doi/abs/10.3171/jns.1999.90.3.0463

Clinical significance of chemosensitivity in chronic heart failure

Increased chemosensitivity has been observed in HF (heart failure) and, in order to clarify its pathophysiological and clinical relevance, the aim of the present study was to investigate its impact on neurohormonal balance, breathing pattern, response to exercise and arrhythmic profile.

Those with enhanced chemosensitivity to both hypoxia and hypercapnia (i.e. HVR and HCVR), compared with those with normal chemosensitivity, had significantly (all P<0.01) higher noradrenaline (norepinephrine) and BNP (B-type natriuretic peptide) levels, higher prevalence of daytime and night-time CSR, worse NYHA (New York Heart Association) class and ventilatory efficiency [higher VE (minute ventilation)/VCO(2) (carbon dioxide output) slope], and a higher incidence of chronic atrial fibrillation and paroxysmal non-sustained ventricular tachycardia, but no difference in left ventricular volumes or LVEF. A direct correlation was found between HVR or HCVR and noradrenaline.

Clin Sci (Lond). 2008 Apr;114(7):489-97.

Impaired autonomic function results in impaired cerebral regulation

The absence of an increase in the power of 0.1 Hz blood pressure and cerebral blood flow velocity oscillations confirmed autonomic neuropathy in the diabetic patients. Gain analysis did not show altered cerebral regulation. The decrease in phase shift in the patients indicates a more passive transmission of neck suction-induced blood pressure fluctuations onto the cerebrovascular circulation, i.e. altered cerebral regulation, in the patients, and is therefore suited to identifying subtle impairment of cerebral regulation in these patients.
http://www.springerlink.com/content/14m7g478j7ux11hv/

Superior cervical ganglionectomy caused a marked decrease in noradrenaline concentrations in major cerebral arteries

Superior cervical ganglionectomy caused a marked decrease in noradrenaline concentrations in major cerebral arteries (−77%), although the reduction was less pronounced (−34%) in small pial vessels. Sympathectomy decreased by 33% 5-HT concentrations in the major cerebral arteries but was without effect on 5-HT levels in the small pial vessels.

Journal of Neurochemistry

Volume 56 Issue 2, Pages 681 - 689

Published Online: 5 Oct 2006

Received March 28, 1990 revised manuscript received July 12, 1990; accepted August 14, 1990.

Experimental study of progressive facial hemiatrophy: effects of cervical sympathectomy in animals

Progressive facial hemiatrophy (Romberg's syndrome) is of unknown cause and uncertain pathogenesis. The main pathogenetic hypotheses are: sympathetic system alterations, localized scleroderma, trigeminal changes, possibly of genetic origin. To test the hypothesis of sympathetic system alterations, we designed an experimental model with ablation of the superior cervical sympathetic ganglion in rabbits, cats and dogs. All the animals were operated upon when 30 days old and were examined monthly for 1 year. During this period localized alopecia, corneal ulceration, keratitis, strabismus, enophthalmos, ocular atrophy, hemifacial atrophy and slight bone atrophy on the side of the sympathectomy were observed. Thus, cervical sympathectomy reproduces in animals the principal clinical alterations of Romberg's syndrome. Our data suggest that the sympathetic system is involved in the pathogenesis of this syndrome.

Rev Neurol (Paris). 1991;147(8-9):609-11.

sympathectomy causes qualitative alterations in bone modeling and remodeling

The results further support that a regional sympathectomy causes qualitative alterations in bone modeling and remodeling, leading to bone resorption.
J Auton Nerv Syst. 2000 Jan 14;78(2-3):113-6.

noradrenaline loss in the sympathetic nervous system of the heart

Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders.
Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.
Semin Neurol. 2003 Dec;23(4):423-33.

Psychoneurological applications of endoscopic sympathetic blocks

In addition to more widely and longer known indications of ETS, various neurological disorders and psychologically stressful situations in their worst expressions might be alleviated by the reversible ESB procedure. The patients with social phobia, especially those who have also blushing and/or stage fright type of heart racing, benefit from the ESB. The disturbances of the sympathetic nervous system, e. g. in Parkinson's disease and multiple system atrophy might be alleviated with sympathetic block, especially the extrapyramidal symptoms in these diseases. In migraine, sympathetic surgery has been noted to give some help. The unilateral left-sided block has been effective in long QT-syndrome type arrhythmias. In schizophrenia, the phobic, paranoic or confusional reactions have been tentatively treated by the sympathetic block.
Clin Auton Res. 2003 Dec;13 Suppl 1:I20-1; discussion I21.

heart rate was significantly reduced at rest (14%), at sub-maximal exercise (12.3%)

heart rate was significantly reduced at rest (14%), at sub-maximal exercise (12.3%)

heart rate was significantly reduced at rest (14%), at sub-maximal exercise (12.3%), and at peak exercise (5.7%), together with a significant increase in oxygen pulse (11.8, 12.7, and 7.8%, respectively). The rate pressure product (RPP) was also significantly reduced following the surgical procedure at all three study stages, while all other physiological variables measured remained unchanged. It is suggested that thoracic-sympathetic denervation affects the heart, sweating, and circulation of the respective denervated region

Eur J Appl Physiol. 2008 Sep;104(1):79-86. Epub 2008 Jun 10.

"Other therapies included sympathectomy, severing the nerves to blood vessels (a surgery with a great risk of complication!)"

Your money or your life: strong medicine for America's health care system

By David M. Cutler

Oxford University Press US, 2005

Carbon dioxide absorption into the blood during thoracoscopic surgery

Respiratory function and pulmonary gas exchange are affected in thoracoscopic procedures where a pneumothorax is introduced using CO2. Carbon dioxide absorption into the blood during thoracoscopic surgery using intrathoracic carbon dioxide insufflation may lead to respiratory acidosis, increased ventilation requirements, and possible serious cardiovascular compromise.
http://www.koreamed.org/SearchBasic.php?RID=173908&DT=1

lactic acidosis, complication of thoracoscopic sympathectomy

We report a case of severe lactic acidosis in a patient undergoing thoracoscopic sympathectomy under general anesthesia who received repeated albuterol.
Lactic acidosis can occur in two different clinically distinguishable categories. The first (type A) occurs when oxygen delivery to the tissues is compromised. The second (type B) occurs when either lactate production is increased or lactate removal is decreased without obvious oxygen delivery problems. ^7,8
β-2 Receptor activation produces excess glycogenolysis and lipolysis. ¹⁰ Increased glycogenolysis eventually leads to increased concentrations of pyruvate. Pyruvate is converted to acetyl CoA, which enters the citric acid cycle. If pyruvate does not enter this aerobic pathway, it is converted to lactate instead, thereby potentially causing lactic acidosis.
journals.lww.com › Home › August 2003 - Volume 99 - Issue 2

sympathectomy further increases muscle protein degradation of acutely diabetic rats

Muscle & Nerve

Volume 38 Issue 2, Pages 1027 - 1035

Unilateral Pulmonary Edema with Contralateral Thoracic Sympathectomy

A case is presented of pathologically proved unilateral pulmonary edema due to uremia and blood transfusion.
The lung that was spared had been denervated by a thoracic sympathectomy eight years earlier. That this
denervation may have been responsible for the unilaterailty of the pulmonary edema is suggested by experimen-
tal evidence supporting a neurogenic etiology of noncardiac pulmonary edema.
1975;68;736-739 Chest

respiratory and hemodynamic changes due to both CO2 absorption and the effects of increased intraperitoneal pressure

Carbon dioxide pneumoperitoneum has been shown to produce respiratory and hemodynamic changes due to both CO₂ absorption and the effects of increased intraperitoneal pressure. We have measured the blood gas, end-tidal CO₂, and hemodynamic changes produced during extraperitoneal CO₂ insufflation (n=22). These have been compared with the changes occurring during CO₂ pneumoperitoneum (n=11) under standardized anesthetic conditions.
Our results suggest that extraperitoneal CO₂ insufflation may be safer than CO₂ pneumoperitoneum in patients with preexisting cardiorespiratory disease.
http://www.springerlink.com/content/327x6038183t5321/