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
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.
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
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
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
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.