Cerebrovascular physiology – article alert #79

Vasopressors and the brain

393- Cerebral blood flow is determined by arterial pressure and not bypass flow rate – Schwartz (letter to the editor regarding article #154 of article alert #35)

Brain monitoring

394-Comparison of 4 near-infrared spectroscopy devices show that they are only suitable for monitoring cerebral oxygenation trends in preterm infants – Schneider et al.

Obesity and the brain

395- The effects of obesity on the cerebral vasculature – Dorrance et al.

Brain autoregulation

396- Assessing cerebrovascular autoregulation from critical closing pressure and resistance area product during upright posture in aging and hypertension – Robertson et al.

Cardiovascular disease and the brain

397- Cognitive impairment and cardiovascular disease: So near, so far – Picano et al.

Ventilation and the brain

398- Effect of ventilation on cerebral oxygenation in patients undergoing surgery in the beach chair position: a randomized controlled trial – Murphy et al.

 

 

 

 

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On the need to monitor more than one cerebral artery in future cerebrovascular studies…

I just read another interesting manuscript by Ogoh’s team entitled Regional redistribution of blood flow in the external and internal carotid arteries during acute hypotension.

In that study, the authors were interested in the changes in external carotid artery (ECA) blood flow following acute hypotension and whether the latter changes influence internal carotid artery (ICA) blood flow regulation. The authors observed clear regional differences in ICA and ECA blood flow in response to acute hypotension (using the thigh cuff method). Indeed, while ICA blood flow lowered in response to hypotension and then quickly recovered to baseline levels, ECA blood was also reduced but that reduction in blood flow was maintained during the entire recovery period.

According to the authors

This finding suggests that the selective redistribution of blood flow from the ECA to support the recovery of ICA blood flow may reflect a neuroprotective mechanism that serves to optimize intracranial blood flow and oxygenation during acute hypotension.

and

In this sense, the peripheral vasculature associated with the ECA may be an important and hitherto unrecognized site that contributions toward intracranial cerebral blood flow regulation.

This is really interesting.

However, the aim of this small post is rather to point out that with the publication of such results, coupled to those suggesting regional differences in cerebral blood flow distribution during exercise, cerebral autoregulation and cerebrovascular reactivity to CO2, will it still be possible to monitor blood flow/blood flow velocity in only one cerebral artery (the beloved MCA for example) in upcoming studies ??

In a recent review on cerebral autoregulation, we have suggested that

New technologies permit a more integrative evaluation of the cerebrovascular function in response to different challenges. Future studies need to consider regional differences in CBF regulation during blood pressure manipulation

Let me revise that last sentence…

Future studies will have to consider regional differences in CBF regulation…whatever thinkable experimental conditions.

Trying to publish a story focusing on only one cerebral artery will most likely become, in a near future, as hard as to publish a vasopressor story using near-infrared spectroscopy alone…

What do you think?

Most viewed Physiology research articles in April 2014!

Great news! One recent manuscript published at Frontiers in Physiology, which is part of our research theme on cerebral oxygenation, is in the Top 10 Most viewed Physiology research articles in April 2014 !

That paper is entitled  Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion by Anne-Sophie G.T. Bronzwaer, Wim J. Stok, Berend E. Westerhof and Johannes J. Van Lieshout.

Our research theme now have 15 articles.

If you are interested in cerebral oxygenation or cerebrovascular physiology, you have to go read these papers !

Cerebrovascular physiology – article alert #78

Cardiopulmonary bypass and the brain

390- Experimental treatment of superior venous congestion during cardiopulmonary bypass – Tovedal et al.

Dehydration and the brain

391- Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans – Trangmar et al.

Cardiac surgery and the brain

392- Mortality predicted by preinduction cerebral oxygen saturation after cardiac operation – Sun et al.

 

Cerebrovascular physiology – article alert #77

Obstructive sleep apnea and the brain

386- Cerebral oxygenation in patients with obstructive sleep apnea. Effects of hypoxia at altitude and of acetazolamide – Ulrich et al.

Coronary artery bypass surgery and the brain

387- Influence of intraoperative cerebral oximetry monitoring on neurocognitive function after coronary artery bypass surgery: a randomized, prospective study – Colak et al.

Diabetes and the brain

388- Regarding “The effects of an exercise and lifestyle intervention program on cardiovascular, metabolic factors and cognitive performance in middle-Aged adults with type 2 diabetes: a pilot study. Can J Diabetes 2013;37:214-9 (see #217 from article alert #47) ” – Paquette and Brassard

Hyperthermia and the brain

389- Hyperthermia modulates regional differences in cerebral blood flow to changes in CO2 – Ogoh et al.