sympathectomy affects the brain: December 2012

cell body reorganization in the spinal cord after sympathectomy

The amount of compensatory sweating depends on the patient, the damage that the white rami communicans incurs, and the amount of cell body reorganization in the spinal cord after surgery.
Other potential complications include inadequate resection of the ganglia, gustatory sweating, pneumothorax, cardiac dysfunction, post-operative pain, and finally Horner’s syndrome secondary to resection of the stellate ganglion.
www.ubcmj.com/pdf/ubcmj_2_1_2010_24-29.pdf

After severing the cervical sympathetic trunk, the cells of the cervical sympathetic ganglion undergo transneuronic degeneration
After severing the sympathetic trunk, the cells of its origin undergo complete disintegration within a year.
http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0442.1967.tb00255.x/abstract

Monday, December 10, 2012

The vasodilating effect of spinal dorsal column stimulation is mediated by sympathetic nerves - Springer

The vasodilating effect of spinal dorsal column stimulation is mediated by sympathetic nerves - Springer: "Immediately after sympathectomy, the contralateral right arm became increasingly cold and cyanotic and the patient complained of chronic painful coldness and severe cold-intolerance in the right arm. Attempts to pharmacologically vasodilate the arm with felodipine did not affect the local vasoconstriction and pain. Dorsal column stimulation (associated with symmetrical paraesthesia in both arms) induced an immediate and marked (ten-fold) increase in skin blood flow in the right arm (and in the leg), whereas skin blood flow in the left arm remained unaffected. The lack of vasomotor response in the left arm was not due to maximal vasodilatation at rest, since skin blood flow in the left arm showed a normal capacity for axon reflex vasodilatation following antidromic activation of sensory afferents. The results suggest that the marked vasodilatation induced by dorsal column stimulation is mediated by sympathetic vasomotor fibres, via modulation of central neuronal circuits involved in the regulation of skin sympathetic discharge."

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Saturday, December 1, 2012

Transection below T8-T10 is not accompanied by reflex sweating

Reflex sweating in patients with spina... [Arch Phys Med Rehabil. 1977] - PubMed - NCBI: "Sweat glands derive their innervation from the sympathetic nervous system. The spinal sympathetic structures that are located in the intermediolateral areas extend from T1-L2 segments and are under the control of hypothalamic centers. Cord transection abolishes the supraspinal control of sudorimotor function. Since sympathetic innervation does not follow a clear segmental distribution, normal sweating may be preserved at a higher or lower level than skin sensation. Nonthermoregulatory reflex sweating is an indication of unchecked spinal cord facilitation and is precipitated by afferent stimuli from bladder, rectum, and various other sources. It is usually a manifestation of mass reflex or autonomic crisis and occurs particularly in cervical or high thoracic lesions. Transection below T8-T10 is not accompanied by reflex sweating. The phenomenon of thermal relfex sweating is controversial. Although some aspects of nonthermoregulatory reflex sweating are still unclear, proper immediate and continuing preventive management will reduce the incidence of this and other autonomic manifestations. "

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autonomic vulnerability or visceral dysfunction may precipitate or aggravate mental symptoms

dynamic cerebral autoregulation is altered by ganglion blockade

After ganglion blockade, systolic and pulse pressure decreased significantly by 13% and 26%, respectively. CBF velocity decreased by 6% (P <0.05). In the very low frequency range (0.02 to 0.07 Hz), mean blood pressure variability decreased significantly (by 82%), while CBF velocity variability persisted. Thus, transfer function gain increased by 81%. In addition, the phase lead of CBF velocity to arterial pressure diminished. These changes in transfer function gain and phase persisted despite restoration of arterial pressure by infusion of phenylephrine and normalization of mean blood pressure variability by oscillatory lower body negative pressure.

Conclusions-: These data suggest that dynamic cerebral autoregulation is altered by ganglion blockade. We speculate that autonomic neural control of the cerebral circulation is tonically active and likely plays a significant role in the regulation of beat-to-beat CBF in humans.

Circulation. 106(14):1814-1820, October 1, 2002.

second thoracic sympathetic ganglion was most commonly located (50%) in the second intercostal space

anatomic variations of the T2 nerve root

6 (9.1%) sides showed a single large ganglion formed by the stellate and the second thoracic sympathetic ganglia. The second thoracic sympathetic ganglion was most commonly located (50%) in the second intercostal space. Conclusion: The anatomic variations of the intrathoracic nerve of Kuntz and the second thoracic sympathetic ganglion were characterized in human cadavers. Journal of thoracic and cardiovascular surgery Y. 2002, vol. 123, No. 3, pages 498-501 [bibl. : 14 ref. http://www.refdoc.fr/Detailnotice?idarticle=9466218

decreased conditioning-related activity in insula and amygdala after autonomic denervation

The degree to which perceptual awareness of threat stimuli and bodily states of arousal modulates neural activity associated with fear conditioning is unknown. We used functional magnetic neuroimaging (fMRI) to study healthy subjects and patients with peripheral autonomic denervation to examine how the expression of conditioning-related activity is modulated by stimulus awareness and autonomic arousal. In controls, enhanced amygdala activity was evident during conditioning to both "seen" (unmasked) and "unseen" (backward masked) stimuli, whereas insula activity was modulated by perceptual awareness of a threat stimulus. Absent peripheral autonomic arousal, in patients with autonomic denervation, was associated with decreased conditioning-related activity in insula and amygdala. The findings indicate that the expression of conditioning-related neural activity is modulated by both awareness and representations of bodily states of autonomic arousal.

http://www.ncbi.nlm.nih.gov/pubmed/11856537

Segmental myoclonus was associated with thoracic sympathectomy

Spinal myoclonus was associated with laminectomy, remote effect of cancer, spinal cord injury, post-operative pseudomeningocele, laparotomy, thoracic sympathectomy, poliomyelitis, herpes myelitis, lumbosacral radiculopathy, spinal extradural block, and myelopathy due to demyelination, electrical injury, acquired immunodeficiency syndrome, and cervical spondylosis.

http://www.ncbi.nlm.nih.gov/pubmed/3753263

Spinal myoclonus is typically associated with a localized area of damaged tissue (focal lesion). The injured area may include direct damage of the spinal cord or may cause abnormal changes in the function of the spinal cord.

http://www.wemove.org/myo/myo_pc.html

Spinal myoclonus following a peripheral nerve injury: a case report

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2526081/

decrease in CBF induced by sympathectomy cannot be attributed to hypersensitivity

Thus the decrease in CBF induced by chronic sympathectomy cannot be attributed to the development of hypersensitivity to catecholamines. This decrease remained stable whatever the value of resting flow and was maintained under anesthesia. It is concluded that, as in the peripheral circulation, chronic sympathectomy affects the equilibrium of the vascular smooth muscle fibers, but that circulating amines play no compensatory role in the cerebral circulation because of the blood-brain barrier.

http://www.sciencedirect.com/science/article/pii/0006899385902434

After the sympathectomy, the high night time excretion of melatonin was abolished

The amount of 6-sulphatoxymelatonin, the chief metabolite of melatonin, in the urine was measured in nine patients, who were subjected to bilateral sympathectomy at the second thoracic ganglionic level for treatment of hyperhidrosis of the palms. All patients showed before surgery a normal 6-sulphatoxymelatonin excretion with a peak in the excretion during the night time. After the sympathectomy, the high night time excretion was clearly abolished in five patients but remained high in four patients...
http://www.ncbi.nlm.nih.gov/pubmed/16647807

LIMITED SYMPATHECTOMY DOES NOT REDUCE SEVERITY OF SIDE-EFFECTS

On univariate and multivariate analysis, the extent of denervation was not associated with the occurrence or the severity of compensatory sweating.

Compensatory sweating and temporary relief/recurrence were equally considered to be the main causes of dissatisfaction. CONCLUSION: Compensatory sweating was the most common long-term complication of thoracodorsal sympathectomy for primary hyperhidrosis. Its incidence and severity were not associated with the extent of sympathectomy.

http://www.ncbi.nlm.nih.gov/pubmed/12514588

Muliptle organ failure as a consequence of elective sympathectomy

In the post-sympathectomy patient, the abnormalsympathetic skin response may lead to peripheral vascular failureor the reduced cardiac chronotropic response may impair thebody’s capacity to compensate for shock. These may havecontributed to the rapid development of shock and severe multipleorgan dysfunction syndrome in this patient.
He had multiple organ dysfunction syndrome develop, with severerenal and hepatic failure, grade II hepatic encephalopathy,and disseminated intravascular coagulation. He responded remarkablywell to aggressive supportive measures including forced alkalinediuresis, and he was eventually discharged home after 1 month. The patient was previously a healthy, physically fit, nonsmoker.He worked as a body building trainer and led an active, sportylifestyle. The only significant medical history was that hehad received thoracic sympathectomy for axillary hyperhidrosis4 years ago at another hospital.

http://ats.ctsnetjournals.org/cgi/content/full/84/3/1025

Cell body reorganization in the spinal cord after elective surgery to treat sweaty palms

slowing of the heart rate usually occurs on the second to fourth day after sympathectomy

The rate fell to a level between 40 and 6o per minute, the maximal slowing usually occurring on the second to fourth day after operation. Consistent slowing of the rate was not observed after a unilateral thoracic sympathectomy of either side. While there was some recovery from the maximum bradycardia with the passage of time in most patients, relatively slow resting cardiac rates and failure of tachycardia to develop with postural hypotension or exercise persisted in all patients.

Skoog's12 work has shown that there are marked differences in the number and precise location of the accessory ganglion cells in the cervical region in different patients and on the two sides in the same patient.
Annals of Surgery, 1949 October, Volume 130 Number 4

'Emotional' sweating regulated by neocortex and limbic cortex

Careful observations showed that the forearm sweating responded diversely to various mental stimuli, unlike the palmar sweating whose response was always an increase. Mental arithmetic, mental testing and physical exercise caused an immediate increase in the palmar sweating but often elicited a transient decrease in the forearm sweating, whereas pain, noise, and emotional stimuli consistently provoked an increase of sweating on the forearm as well as on the palm. These observations suggest that the activities of higher centers, presumably involving neocortex and limbic cortex, exert various influences on the central mechanisms of palmar and generalized sweating.
Jpn J Physiol. 1975;25(4):525-36.
http://www.ncbi.nlm.nih.gov/pubmed/1206808

The sympathetic nervous system is responsible for the physiological responses to emotional states

The common epithet of “fight or flight” is being enlarged to be “fight, flight, or fright” or even “fight, flight, fright, or freeze.” Cannon’s original contribution was a catchy phrase to express some of what the nervous system does in response to a threat, but it is incomplete. The sympathetic system is responsible for the physiological responses to emotional states. The name “sympathetic” can be said to mean that (sym- = “together”; -pathos = “pain,” “suffering,” or “emotion”). http://cnx.org/content/m46582/latest/?collection=col11496/latest