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• W2093403585 abstract "Point:CounterpointHumans do/do not demonstrate selective brain cooling during hyperthermiaPoint: Humans do demonstrate selective brain cooling during hyperthermiaMatthew D. White, Jesse G. Greiner, and Patrick L. L. McDonaldMatthew D. WhiteLaboratory for Exercise and Environmental Physiology Department of Biomedical Physiology and Kinesiology Simon Fraser University, Burnaby, British Columbia, e-mail: , Jesse G. GreinerLaboratory for Exercise and Environmental Physiology Department of Biomedical Physiology and Kinesiology Simon Fraser University, Burnaby, British Columbia, e-mail: , and Patrick L. L. McDonaldLaboratory for Exercise and Environmental Physiology Department of Biomedical Physiology and Kinesiology Simon Fraser University, Burnaby, British Columbia, e-mail: Published Online:01 Feb 2011https://doi.org/10.1152/japplphysiol.00992.2010This is the final version - click for previous versionMoreSectionsPDF (291 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Selective brain cooling (SBC) is defined by the International Union of Physiological Sciences (11) as “a lowering of the brain temperature either locally or as a whole below arterial blood temperature.” Since the first observations of SBC in hyperthermic, nonhuman mammals (1, 14, 25), there have been efforts to resolve the physiological mechanisms underlying this response (3, 12, 19, 27). It is still hotly debated whether SBC also exists in hyperthermic humans. This contribution is first to give evidence confirming SBC exists in humans, second to outline the mechanisms underlying SBC, third to counter arguments suggesting that SBC is absent in humans, and finally to present a physiological rationale for human SBC.Evidence of Human SBCThe first evidence of human SBC was in passively heated (5) or exercising (4) humans whose tympanic (Tty) dropped below esophageal (Tes) temperature after face fanning. As reviewed by Cabanac (3), SBC has been repeatedly demonstrated in hyperthermic humans. Recent results in neurosurgical patients with both face fanning and continuous ventilation of the upper airways resulted in cooling of parenchymal brain tissue (10). Although this moderate intervention showed similar reductions in Tes (10), suggesting no SBC, both extubation as well as elevated breathing rate and depth in postoperative neurosurgical patients confirmed the existence of human SBC by giving significant lowering of cribriform plate temperature (16). With a more aggressive cooling cap treatment, Liu and colleagues (13) found evidence of human SBC during a ventriculostomy. Brain temperature was lowered to 33–35°C in ∼2 h and maintained at this level over 3 days while rectal temperature (Tre) remained between 36.5 and 37.5°C (13). Employing a novel nasopharyngeal coolant spray, Castrén and colleagues (7) observed a ∼1.5°C drop of Tty within ∼60 min in cardiac arrest patients before their return to spontaneous circulation. Collectively these studies give evidence confirming the existence of human SBC.Mechanisms of SBCThree predominant mechanisms of human SBC include: 1) direct surface heat loss on the cranium, 2) drainage of cooled cutaneous blood from the scalp and face, to allow a countercurrent heat exchange between the intracranial plexus of venous sinuses and internal carotid artery, and 3) thermal hyperpnea-induced heat exchange between the upper airways and the internal carotid artery.Direct surface cooling.During forced convection, at different submaximal exercise intensities, total direct surface cephalic heat loss in humans was ∼200–250 W (21). At an exercise intensity of 150 W (Fig. 1A), the majority of this direct head heat loss was latent or insensible (21). The resulting rise of Tty was slower than that of Tes throughout these exercise sessions and this demonstrated a “heat sink” that was directly involved in cranial heat balance and SBC in hyperthermic humans.Fig. 1.A: total cephalic heat loss in exercising humans during forced convection at three different ambient temperatures (from Ref. 21). B: an illustration of 3 prominent valveless emissary veins including the parietal, angularis oculi, and mastoid veins. During hyperthermia these allow the flow of cooled venous blood from the scalp through the skull to the network of venous sinuses including the cavernous sinus that is juxtaposed to the internal carotid artery (from Cabanac M. News Physiol Sci 1: 41–43, 1986).Download figureDownload PowerPointSurface cooling and countercurrent heat exchange.Following surface cooling of the cranium during hyperthermia (6), the cutaneous blood drains from the cranial subcutaneous venous plexus to the intracranial plexus of venous sinuses through valveless, bidirectional emissary veins and microscopic anastomoses (Fig. 1B). This cooled venous blood drains to the cavernous sinus and other intracranial venous sinuses to give a countercurrent-induced temperature reduction of the main cranial arterial blood supply in the internal carotid artery.Thermal hyperpnea.An elevation of human body temperatures has been demonstrated in numerous studies to give a thermal hyperpnea or hyperthermia-induced (as reviewed in Ref. 27). The physiological need for this response remained obscure in hyperthermic humans who mainly employ sweating and surface evaporative cooling to regulate their core temperature. In contrast to humans, several mammals employ thermal panting or thermal tachypnea as a primary heat loss mechanism during body warming (22). Respiratory evaporative cooling from their upper airways and nasal cavity cools mucosal venous blood that is drained into the intracranium to provide SBC (12, 19). In humans, thermal hyperpnea provides a parallel avenue of heat loss that contributes to SBC. Mariak and colleagues (16) and others groups (7, 13) directly demonstrated that increases or decreases in upper airway ventilation gave proportional changes of intracranial temperatures and confirmed that thermal hyperpnea provides a third avenue of heat loss for human SBC.Counterpoints to Human SBCTympanic and intracranial temperatures.The use of Tty has been debated as to its validity as an index of human intracranial temperature (12, 19, 20). When properly measured, Tty is a good “global index” of directly measured human intracranial temperature (17). Different groups (15, 18) have demonstrated pronounced intracranial radial temperature gradients that decrease from the third and fourth ventricles to the brain meninges. Taking into account the heat loss from the head (Fig. 1A) and these radial temperature gradients, it appears untenable only to assess human SBC from extracranial aortic arch to external jugular temperature differences (20). It appears both Tty and intracranial temperatures (24) need to be employed in future studies to comprehensively resolve the mechanisms underlying SBC.Carotid rete mirable.Some have suggested (12, 19, 20) that without carotid rete that there is no countercurrent heat exchange in the cavernous sinus and, consequently, human SBC is not possible. Several other mammals, including the rabbit and horse, lack a carotid rete but clearly demonstrate SBC (3). Consequently, lack of a carotid rete does not preclude the existence of SBC in humans or other mammals.Intracranial blood flow during hyperthermia.Recently, blood flow velocity in the human middle cerebral artery (MCA) was shown to be reduced during hyper- relative to normothermic temperatures (2, 20). The assumption of these results (2, 20) is that the MCA does not dilate during hyperthermia (23). An alternative explanation is that the MCA, and possibly other cerebral arteries and arterioles, dilate during hyperthermia and give increased cranial perfusion (9, 26). Poiseuille's Law (Q =ΔP·πr4/8ηl) for resistance to flow in blood vessels shows a 20% decrease in cerebral blood velocity corresponds to a blood vessel radius increase of only 5%. To maintain a constant arterial-venous temperature difference (20), with increased cranial perfusion, a substantial cranial surface cooling is needed and it is evident (Fig. 1A). It remains to be explained how MCA velocity, and presumably cranial perfusion (2, 20), is reduced in hyperthermic humans if mean arterial blood pressure is maintained (2) and MCA caliber remains constant.Physiological Benefits of SBCRecent clinical studies confirm that a rapid cranial cooling gives neuroprotection following traumatic brain injury and during cardiac arrest (8). It is evident, however, from telemetry studies of wildebeest cranial temperatures (12) that a physiologically and psychologically stressed, hyperthermic animal appears to abandon SBC. In contrast, resting but hyperthermic animals appear to selectively cool their brains. By selectively cooling the hypothalamus, humans or mammals sweat or pant less and consequently conserve body fluids. Both neuroprotection and body fluid conservation during hyperthermia are important physiological benefits of SBC.ConclusionsDuring hyperthermia, avenues of human SBC include direct cranial surface heat loss, drainage of cooled subcutaneous venous blood to intracranial venous plexuses to give a countercurrent heat exchange with internal carotid artery blood, and upper airway respiratory cooling that helps lower internal carotid artery blood temperature. Recent studies reaffirm the existence of SBC in hyperthermic humans and novel clinical interventions in traumatic brain injured and cardiac arrest patients are providing a venue to further explore the mechanisms underlying this beneficial physiological response.REFERENCES1. Baker MA , Hayward JN. Carotid rete and brain temperature of cat. Nature 216: 139–141, 1967.Crossref | PubMed | ISI | Google Scholar2. Brothers RM , Zhang R , Wingo JE , Hubing KA , Crandall CG. Effects of heat stress on dynamic cerebral autoregulation during large fluctuations in arterial blood pressure. J Appl Physiol 107: 1722–1729, 2009.Link | ISI | Google Scholar3. Cabanac M. Human Selective Brain Cooling. NY, NY: Springer-Verlag, 1996, p. 114.Google Scholar4. Cabanac M , Caputa M. Natural selective cooling of the human brain: evidence of its occurrence and magnitude. J Physiol 286: 255–264, 1979.Crossref | PubMed | ISI | Google Scholar5. Cabanac M , Caputa M. Open loop increase in trunk temperature produced by face cooling in working humans. J Physiol 289: 163–174, 1979.Crossref | ISI | Google Scholar6. Caputa M , Perrin G , Cabanac M. Ecoulement senguin reversible dans la veine ophtalmique: mecanisme de refroidissment sélectif du cerveau humain. Comptes Rendues de L'Acadamie des Sciences, Paris (CR Acad Sc Paris) 287: 1011–1014, 1978.Google Scholar7. Castrén M , Nordberg P , Svensson L , Taccone F , Vincent JL , Desruelles D , Eichwede F , Mols P , Schwab T , Vergnion M , Storm C , Pesenti A , Pachl J , Guérisse F , Elste T , Roessler M , Fritz H , Durnez P , Busch HJ , Inderbitzen B , Barbut D. Intra-arrest transnasal evaporative cooling: a randomized, prehospital, multicenter study (PRINCE: Pre-ROSC IntraNasal Cooling Effectiveness). Circulation 122: 729–736, 2010.Crossref | ISI | Google Scholar8. Christian E , Zada G , Sung G , Giannotta SL. A review of selective hypothermia in the management of traumatic brain injury. Neurosurg Focus 25: E9, 2008.Crossref | ISI | Google Scholar9. Gonzalez-Alonso J , Dalsgaard M , Osada T , Volianitis S , Dawson E , Yoshiga C , Secher NH. Brain and central haemodynamics and oxygenation during maximal exercise in humans. J Physiol 557: 331–342, 2004.Crossref | PubMed | ISI | Google Scholar10. Harris BA , Andrews PJ , Murray GD. Enhanced upper respiratory tract airflow and head fanning reduce brain temperature in brain-injured, mechanically ventilated patients: a randomized, crossover, factorial trial. Br J Anaesth 98: 93–99, 2007.Crossref | ISI | Google Scholar11. IUPS Thermal Physiology Commission. Glossary of terms for thermal physiology (3rd ed.). Revised by The Commission for Thermal Physiology of the International Union of Physiological Sciences. Jpn J Physiol 51: 245–280, 2001.Google Scholar12. Jessen C. Selective brain cooling in mammals and birds. Jpn J Physiol 51: 291–301, 2001.Crossref | PubMed | Google Scholar13. Liu WG , Qiu WS , Zhang Y , Wang WM , Lu F , Yang XF. Effects of selective brain cooling in patients with severe traumatic brain injury: a preliminary study. J Int Med Res 34: 58–64, 2006.Crossref | ISI | Google Scholar14. Magilton J , Swift C. Description of two physiological heat exchange systems for the control of brain temperature. In: IEEE Conference Record: Fifth Annual Rocky Mountain Bioengineering Symposium, 1968, p. 24–27.Google Scholar15. Mariak Z , Lewko J , Luczaj J , Polocki B , White MD. The relationship between directly measured human cerebral and tympanic temperatures during changes in brain temperatures. Eur J Appl Physiol 69: 545–549, 1994.Crossref | ISI | Google Scholar16. Mariak Z , White MD , Lewko J , Lyson T , Piekarski P. Direct cooling of the human brain by heat loss from the upper respiratory tract. J Appl Physiol 87: 1609–1613, 1999.Link | ISI | Google Scholar17. Mariak Z , White MD , Lyson T , Lewko J. Tympanic temperature reflects intracranial temperature changes in humans. Pflugers Arch 446: 279–284, 2003.Crossref | PubMed | ISI | Google Scholar18. Mellergard P , Nordstrom CH. Epidural temperature and possible intracerebral temperature gradients in man. Br J Neurosurg 4: 31–38, 1990.Crossref | Google Scholar19. Mitchell D , Maloney SK , Jessen C , Laburn HP , Kamerman PR , Mitchell G , Fuller A. Adaptive heterothermy and selective brain cooling in arid-zone mammals. Comp Biochem Physiol B Biochem Mol Biol 131: 571–585, 2002.Crossref | PubMed | ISI | Google Scholar20. Nybo L , Secher NH , Nielsen B. Inadequate heat release from the human brain during prolonged exercise with hyperthermia. J Physiol 545: 697–704, 2002.Crossref | PubMed | ISI | Google Scholar21. Rasch W , Samson P , Cote J , Cabanac M. Heat loss from the human head during exercise. J Appl Physiol 71: 590–595, 1991.Link | ISI | Google Scholar22. Robertshaw D. Mechanisms for the control of respiratory evaporative heat loss in panting animals. J Appl Physiol 101: 664–668, 2006.Link | ISI | Google Scholar23. Serrador JM , Picot PA , Rutt BK , Shoemaker JK , Bondar RL. MRI measures of middle cerebral artery diameter in conscious humans during simulated orthostasis. Stroke 31: 1672–1678, 2000.Crossref | PubMed | ISI | Google Scholar24. Simon E. Tympanic temperature is not suited to indicate selective brain cooling in humans: a re-evaluation of the thermophysiological basics. Eur J Appl Physiol 101: 19–30, 2007.Crossref | ISI | Google Scholar25. Taylor CR. The vascularity and possible thermoregulatory function of horns in goats. Physiological Zoology 39: 127–139, 1966.Crossref | Google Scholar26. Thomas SN , Schroeder T , Secher NH , Mitchell JH. Cerebral blood flow during submaximal and maximal dynamic exercise in humans. J Appl Physiol 67: 744–748, 1989.Link | ISI | Google Scholar27. White MD. Components and mechanisms of thermal hyperpnea. 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