We measured arterial pressure and cerebral blood flow (CBF) velocity in 12 healthy subjects (aged 29+/-6 years) before and after ganglion blockade with trimethaphan. CBF velocity was measured in the middle cerebral artery using transcranial Doppler. The magnitude of spontaneous changes in mean blood pressure and CBF velocity were quantified by spectral analysis. The transfer function gain, phase, and coherence between these variables were estimated to quantify dynamic cerebral autoregulation. 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.
http://www.problemsinanes.com/pt/re/dyslipidaemia/abstract.00003017-200210010-00017.htm;jsessionid=PX6phQHYFG5PD1p2DMS1cJLvG1TbtLLLH0bfJT6vKJgLLx1zn0Xf!1816077220!181195629!8091!-1?nav=reference
It’s not unusual to hear people describe themselves as emotionally 'colder'
It’s not unusual to hear people who have undergone sympathectomies describe themselves as feeling emotionally “colder” than before. Among psychologists and neurologists alike there is concern, but no evidence, that the procedure limits alertness and arousal as well as fear, and might affect memory, empathy and mental performance. Professor Ronald Rapee, the director of the Centre of Emotional Health at Sydney’s Macquarie University, says he’s counselled several people who complain of feeling “robot-like” in the long-term wake of the operation. “They’re happy they no longer blush, but they miss the highs and lows they used to feel.”
(John van Tiggelen, Good Weekend Magazine, The Age and the Sydney Morning Herald, 10th March 2012)
https://archive.today/uURge
(John van Tiggelen, Good Weekend Magazine, The Age and the Sydney Morning Herald, 10th March 2012)
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