Brain cooling in humans ? anatomical considerations

Zenker, W.; Kubik, Stefan

doi:10.1007/bf00186829

Cited by 134 publications

(131 citation statements)

References 42 publications

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“…The excess of venous channels in relation to the arterial supply of the spinal epidural area has lead to many speculations about the function of the vertebral veins (Herlihy, 1947;Clemens, 1961a;Vogelsang, 1970;Bruyn and Bosma, 1976;Zenker et al, 1994;Zenker and Kubik, 1996), but to date this disproportion has not been explained in functional terms. Herlihy (1947) stated that the vertebral venous system has to be considered as a provision of nature to equalize venous pressure, to redistribute blood, and, in pathological conditions of the vena cava, to serve as an alternative path for the continuation of the circulation.…”

Section: Functional Considerationsmentioning

confidence: 99%

“…Others have stressed the role of the internal vertebral venous plexus in cerebrospinal fluid reabsorption (Zenker et al, 1994). Recently, the vertebral venous system has been implied in relation to evaporation-induced ''selective brain cooling'' via its connections with the external vertebral venous system (Zenker and Kubik, 1996). …”

Section: Functional Considerationsmentioning

confidence: 99%

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Morphology of the human internal vertebral venous plexus: A cadaver study after intravenous araldite CY 221 injection

et al. 1997

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Reviewing the literature on the vascular anatomy of the spinal epidural space, it appeared that the knowledge of the internal vertebral venous plexus is limited. Injection studies of the entire internal vertebral venous plexus after application of modern techniques, to the best of our knowledge, have never been performed. Based on the clinical importance of these structures, it was decided to study the human vertebral venous system after Araldite CY 221 injection, in order to update the morphological characteristics of the internal vertebral venous system.The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. All cadavers were dissected and the posterior and anterior internal vertebral venous plexuses were studied in detail.The anterior part of the internal vertebral venous plexus is fairly constant. On the contrary, the posterior internal vertebral venous plexus showed a striking segmental and interindividual variability. In the tho- The plexus venosus vertebralis is an extensive vascular network that has largely escaped attention of anatomists, physiologists and clinicians. It is considered to be valveless and extends along the entire length of the vertebral column, finding a cranial terminus in the dural sinuses. It parallels, joins and at the same time bypasses the longitudinal veins of the thoracoabdominal cavity. Like the azygos veins, it unites the superior and inferior vena cava, but on the other hand it is protected from direct thoracoabdominal pressure waves because of its course in the rigid spinal canal (Batson,

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Section: Functional Considerationsmentioning

confidence: 99%

Section: Functional Considerationsmentioning

confidence: 99%

Morphology of the human internal vertebral venous plexus: A cadaver study after intravenous araldite CY 221 injection

et al. 1997

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“…The evaluation of this additional or alternative mode through which total or regional brain cooling in humans could operate requires a look at the gross anatomy of the vascular system of the brain and skull, which is based on a recent study by Zenker and Kubik [35]. The blood supply to the brain is provided by two sets of branches that arise from all cerebral arteries at the base of the brain and the circle of Willis: central and cortical.…”

Section: Humansmentioning

confidence: 99%

“…The thick red lines mark cortical regions remote from venous sinuses and assumed to be warmed by heat exchange between arteries and veins carrying warm blood returning from the brain parenchyma. From [35], with permission.…”

Section: Birdsmentioning

confidence: 99%

Selective Brain Cooling in Mammals and Birds.

Jessen

2001

JJP

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The term selective brain cooling (SBC) refers to the lowering of brain temperature, either locally or as a whole, below arterial blood temperature. SBC has been reported to occur in laboratory experiments on many mammalian and avian species and was often seen as a mechanism serving to protect the brain, which was more or less intuitively supposed to be more susceptible to thermal damage than other organs of the body were. So far, however, no evidence has been found showing that brain tissues are less tolerant of elevated temperatures than other tissues are [1,2], and recent studies have cast great doubt on the validity of the protection concept of SBC (see below). This article reviews the present knowledge of the thermal and nonthermal factors conducive to the development of SBC. It is organized in four major sections. The first deals with species in which the presence of a carotid rete provides a well-defined anatomical structure capable of cooling all arterial blood destined for the brain, and thus cooling the brain as a whole. The second section concerns nonhuman mammals in which the carotid rete is either rudimentarily developed or missing; in these species SBC is very likely to be restricted to certain regions of the brain. The situation in humans deserves a separate section. On the one hand, no specialized heat exchanger like the carotid rete is available to cool the arterial blood before it enters the large brain, but on the other a sweating scalp and face may provide heat sinks of sizable capacity for cooling regions of the brain near its outer Key words: selective brain cooling, brain temperature, carotid rete, mammals, birds.Abstract: Artiodactyls and felids have a carotid rete that can cool the blood destined for the brain and consequently the brain itself if the cavernous sinus receives cool blood returning from the nose. This condition is usually fulfilled in resting and moderately hyperthermic animals. During severe exercise hyperthermia, however, the venous return from the nose bypasses the cavernous sinus so that brain cooling is suppressed. This is irreconcilable with the assumption that the purpose of selective brain cooling (SBC) is to protect the brain from thermal damage. Alternatively, SBC is seen as a mechanism engaging the thermoregulatory system in a water-saving economy mode in which evaporative heat loss is inhibited by the effects of SBC on brain temperature sensors. In nonhuman mammals that do not have a carotid rete, no evidence exists of wholebrain cooling. However, the surface of the cavernous sinus is in close contact with the base of the brain and is the likely source of unregulated regional cooling of the rostral brain stem in some species. In humans, the cortical regions next to the inner surface of the cranium are very likely to receive some regional cooling via the scalp-sinus pathway, and the rostral base of the brain can be cooled by conduction to the nearby respiratory tract; mechanisms capable of cooling the brain as a whole have not been found. Studies using conventiona...

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“…A large descriptive anthropology literature provides strong evidence that the dural plexus and its connections became larger and more complex with hominid evolution [5][6][7][8]. To ignore this literature and the importance of understanding the role of the dura in the context of the function of the human CNS is to ignore potential novel treatments for infants presenting with subdural collections.…”

mentioning

confidence: 99%