Cerebrovascular physiology – article alert #72

Regulation of brain blood flow

353- Circadian cerebrovascular reactivity to CO2 –  Strohm et al.

354- Why is the neural control of cerebral autoregulation so controversial? Ainslie and Brassard

355- Capillary pericytes regulate cerebral blood flow in health and disease  – Hall et al.

Brain autoregulation

356- Dynamic Cerebral Autoregulation and Tissue Oxygenation in Amnestic Mild Cognitive Impairment – Tarumi et al.

357- Dynamic cerebral autoregulation is heterogeneous in different subtypes of acute ischemic stroke – Guo et al.

Brain monitoring

358- Cerebral oximetry in cardiac anesthesia – Vretzakis et al.

Intracerebral hemorrhage and the brain

359- Optimal cerebral perfusion pressure in patients with intracerebral hemorrhage: an observational case series – Diedler et al.


Interested in becoming a contributor ?

One of my goals when I started this blog was to develop an interactive site where grad students, postdoc and researchers in cerebrovascular physiology could discuss published papers, study designs and methods related to this research area.

Now, it would be really interesting if grad students, postdoc and researchers following this blog could contribute with guest posts !

So, if you would like to publish a post related to cerebrovascular physiology, just send me an email at lephysiologiste@gmail.com.

I am looking forward to hearing from you !

Another research theme on brain physiology at Frontiers !

Regular readers know that we have a research topic on cerebral oxygenation at Frontiers in Physiology.

For those interested in brain physiology during exercise, this journal has a research theme covering that issue (Topic Editors: Stephane Perrey, Montpellier I University, France, Sebastien Racinais, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Qatar, Olivier GIRARD, ASPETAR – Qatar Orthopaedic and Sports Medicine Hospital, Qatar )

Investigating the human brain and muscle coupling during whole-body challenging exercise

Go have a look !

Cerebrovascular physiology – article alert #71

Vasopressors and the brain

350- A decrease in spatially resolved near-infrared spectroscopy-determined frontal lobe tissue oxygenation by phenylephrine reflects reduced skin blood flow – Ogoh et al.

351- Is hypotension or tissue oxygenation responsible for morbidity and morality after cardiopulmonary bypass? Brassard + Reply to the editor – Ono, Brady and Hogue

Brain injury

352- Cerebral Vascular Regulation and Brain Injury in Preterm Infants – Brew et al.

Vasopressors and reduced cerebral oxygenation determined by NIRS: An illusion ??

Science is great…but can be cruel. I have been lucky enough to work on a really interesting and relevant clinical issue since my postdoc years, that is the influence of vasopressors on cerebral oxygenation.

I have published 3 papers with data coming from postdoc work on that issue and another paper got recently published with data from my own lab.

Still, it is not a secret that extracranial contamination may have an important influence on the NIRS-determined cerebral oxygenation, especially when vasopressors are administered. We recently had a friendly debate about that issue here.

Well, this last paper recently published by my colleagues Shigehiko Ogoh et al. in Anesthesia & Analgesia hit me hard yesterday:

A decrease in spatially resolved near-infrared spectroscopy-determined frontal lobe tissue oxygenation by phenylephrine reflects reduced skin blood flow

This well-written paper is just another piece of evidence against the influence (whether direct or indirect) of vasopressors (phenylephrine and norepinephrine) on cerebral oxygenation, at least when determined by NIRS…

Other evidence has recently been published by my Danish friends and colleagues:

Cutaneous vasoconstriction affects near-infrared spectroscopy determined cerebral oxygenation during administration of norepinephrine.

Extra-cerebral oxygenation influence on near-infrared-spectroscopy-determined frontal lobe oxygenation in heatlhy volunteers: a comparison between INVOS-4100 and NIRO-200NX.

External carotid artery flow maintains near-infrared spectroscopy-determined frontal lobe oxygenation during ephedrine administration

So the question is: Does the reduction in NIRS-determined cerebral oxygenation following vasopressors administration is merely an illusion ?

I recently had an exchange of emails (one of many exchanges on that issue!) with Henrik Sørensen, the lead author of a couple of these papers, and he had these words:

You forced us to come up with some new ideas after your vasopressor-studies in CPH (Copenhagen), now we have forced you to come up with some new ideas too.

Challenge accepted !

Practical Course on Performing Transcranial Doppler Ultrasound

Are you interested/involved in cerebrovascular physiology research and will attend Experimental Biology 2014 in San Diego ?

You cannot miss the practical course on performing transcranial Doppler ultrasound !!

Want more information ??

Below is a message from Dr Caroline Rickards.

Are you investigating cerebral blood flow regulation in humans and would like to learn more about how to perform transcranial Doppler (TCD) ultrasound?

The International Research Network on Cerebral Hemodynamic Regulation (CARNet) is conducting a 2-hour hands-on practical training course on TCD ultrasound during the Experimental Biology meeting in San Diego.

When:  Tuesday April 29, 2014; 2.30-4.30pm
Where: San Diego Marriott Marquis & Marina – Balboa
What: TCD ultrasound theory, hands-on training with experienced investigators, assessment of major intra- and extra-cranial vessels, discover the advantages & limitations of the technique.
How to apply: complete the attached application form and return to Caroline Rickards (caroline.rickards@unthsc.edu) by April 4, 2014.

Space is limited, so please submit your application today!

CARNet TCD Course Application Form (Fillable Form)[2]

Cerebrovascular physiology – article alert #70

Hypotension and the brain

345- Regional re-distribution of blood flow in the external and internal carotid arteries during acute hypotension – Ogoh et al.

Brain monitoring

346-Usefulness of Transcranial Doppler-Derived Cerebral Hemodynamic Parameters in the Noninvasive Assessment of Intracranial Pressure – Wakerley et al.

347- Extra-cerebral oxygenation influence on near-infrared-spectroscopy-determined frontal lobe oxygenation in healthy volunteers: a comparison between INVOS-4100 and NIRO-200NX – Sørensen et al.

Postconcussion syndrome and the brain

348- Exercise treatment for postconcussion syndrome: a pilot study of changes in functional magnetic resonance imaging activation, physiology, and symptoms – Leddy et al.

Hypoxia and the brain

349- The effect of acute hypoxia on regional cerebral blood flow: effect of sympathetic nerve activity – Lewis et al.

Cerebrovascular physiology – article alert #69

Metabolic syndrome and the brain

341- Low cerebral blood flow is associated with lower memory function in metabolic syndrome – Birdsill et al.

Heart failure and the brain

342- Decreased physical activity predicts cognitive dysfunction and reduced cerebral blood flow in heart failure – Alosco et al.

Anesthesia and the brain

343- Does sevoflurane preserve regional cerebral oxygen saturation measured by near-infrared spectroscopy better than propofol? Valencia et al.

Head injury and the brain

344- Cerebrovascular pressure reactivity and cerebral oxygen regulation after severe head injury – Jaeger and lang