The influence of the cranial sympathetic nerves on the architecture of pial arteries in normo- and hypertension was examined. For this purpose the effect of bilateral superior cervical ganglionectomy was evaluated in normotensive rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). The operations were performed at the age of 1 wk, which is just prior to the onset of ganglionic transmission. The length of the inner media contour was measured and the media cross-sectional area was determined planimetrically, with computerized digitalization of projected photographic images of transversely sectioned pial arteries. Four wk after sympathectomy there was a 20% reduction in media cross-sectional area and a consequent reduction in the ratio between media area and calculated luminal radius in the major pial arteries at the base of the brain in WKY but not in SHRSP. Conversely, in small pial arteries linear regression analysis showed that in WKY subjected to ganglionectomy the relationship between media cross-sectional area and luminal radius was significantly larger in arteries with a radius less than 21 microns compared to untreated WKY. No such effect was seen in the corresponding SHRSP vessels. In addition, the cross-sectional area of the internal elastic membrane (IEM) in the basilar arteries of WKY was measured by means of a computerized image-analysing system. Mean cross-sectional area of the IEM was approximately 45% larger following SE than in control animals. The present findings propose a 'trophic' role for the sympathetic perivascular nerves in large pial arteries of the rat. The increased media-radius ratio in the small pial arteries of the WKY following sympathectomy might reflect a compensatory hypertrophy due to reduced protection from the larger arteries against the pressure load. The inability to detect any morphometrically measurable effect of the sympathectomy in the cerebral arteries of SHRSP is probably explained by a marked growth-stimulating effect of the high pressure load in these animals.
http://www.ncbi.nlm.nih.gov/pubmed/7701941
"Sympathectomy is a technique about which we have limited knowledge, applied to disorders about which we have little understanding." Associate Professor Robert Boas, Faculty of Pain Medicine of the Australasian College of Anaesthetists and the Royal College of Anaesthetists, The Journal of Pain, Vol 1, No 4 (Winter), 2000: pp 258-260
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
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
Tuesday, June 5, 2012
Postural Hypotension and Postural Dizziness
The subjects were 204 consecutive non–insulin-dependent patients with diabetes and 408 age- and sex-matched nondiabetic control subjects who underwent physical examinations for preventive reasons at the National Cheng Kung University Hospital between October 1992 and September 1994. Subjects were excluded from the study for sympathectomy, anemia, thyroid disorder, pregnancy, chronic alcohol use, and/or use of anti-Parkinson drugs, narcotics, sedatives, antipsychotic agents, or antidepressants within 2 weeks of the study. The subjects with diabetes included 114 men and 90 women with a mean age ± SD of 57.9 ± 10.5 years. The nondiabetic control subjects were 228 men and 180 women with a mean age ± SD of 57.1 ± 9.5 years.
Postural Hypotension and Postural Dizziness in Patients With Non–Insulin-Dependent Diabetes
Jin-Shang Wu, MD; Feng-Hwa Lu, MD; Yi-Ching Yang, MD; Chih-Jen Chang, MD
[+] Author Affiliations
Arch Intern Med. 1999;159(12):1350-1356. doi:10-1001/pubs.Arch Intern Med.-ISSN-0003-9926-159-12-ioi80679
Postural Hypotension and Postural Dizziness in Patients With Non–Insulin-Dependent Diabetes
Jin-Shang Wu, MD; Feng-Hwa Lu, MD; Yi-Ching Yang, MD; Chih-Jen Chang, MD
[+] Author Affiliations
Arch Intern Med. 1999;159(12):1350-1356. doi:10-1001/pubs.Arch Intern Med.-ISSN-0003-9926-159-12-ioi80679
Causes of orthostatic hypotension - surgical sympathectomy
Causes of orthostatic hypotension (modified from Simon et al9).
Hypovolemia or hemorrhage Addison’s disease Drug-induced hypotension • Antidepressants • Antihypertensives • Bromocriptine • Diuretics • Levodopa • Monoamine oxidase (MOA) inhibitors • Nitroglycerin • Phenothiazines Polyneuropathies • Myeloid neuropathy • Diabetic neuropathy • Guillain-Barre syndrome • Porphyric neuropathy • Vincristine neuropathy Other neurologic disorders • Idiopathic orthostatic hypotension • Multiple sclerosis • Parkinsonism • Posterior fossa tumor • Shy-Drager syndrome • Spinal cord injury with paraplegia • Surgical sympathectomy • Syringomyelia • Syringobulbia • Tabes dorsales (syphilis) • Wernicke’s encephalopathy Cardiovascular disorders Prolonged bed rest or immobilization
http://www.scribd.com/doc/15030687/Dizziness-Classification-and-Pathophysiology
Hypovolemia or hemorrhage Addison’s disease Drug-induced hypotension • Antidepressants • Antihypertensives • Bromocriptine • Diuretics • Levodopa • Monoamine oxidase (MOA) inhibitors • Nitroglycerin • Phenothiazines Polyneuropathies • Myeloid neuropathy • Diabetic neuropathy • Guillain-Barre syndrome • Porphyric neuropathy • Vincristine neuropathy Other neurologic disorders • Idiopathic orthostatic hypotension • Multiple sclerosis • Parkinsonism • Posterior fossa tumor • Shy-Drager syndrome • Spinal cord injury with paraplegia • Surgical sympathectomy • Syringomyelia • Syringobulbia • Tabes dorsales (syphilis) • Wernicke’s encephalopathy Cardiovascular disorders Prolonged bed rest or immobilization
http://www.scribd.com/doc/15030687/Dizziness-Classification-and-Pathophysiology
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