The relation of dehydration of the brain to the spreading depression of Leao

Marshall, Wade H.; Hanna, C. H.; Barnard, George

doi:10.1016/0013-4694(50)90031-9

Cited by 28 publications

(6 citation statements)

References 19 publications

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“…According to this criterion, SD in human cau date and hippocampus has similar properties as in other mammalian spe cies. This extends the comparative investigations which have already de scribed SD in the cerebral cortex of the squirrel monkey [17] and ma caque monkey [13], although in the latter species SD had to be facilitated by brain cooling, air exposure and dehydration [14]. That SD spreads in the brain of a mouse with the same velocity as in the human brain sup ports the hypothesis that it is a simple process mediated by a wave of in creased concentration of potassium ions propagating through the extracel lular space by diffusion, supplemented by depolarization-triggered trans membrane outflux of intracellular K+ ions.…”

Section: Discussionsupporting

confidence: 63%

Functional Ablation by Spreading Depression: Possible Use in Human Stereotactic Neurosurgery

Šramka¹,

Brožek²,

Bureš³

et al. 1977

Stereotact Funct Neurosurg

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Spreading depression (SD) of EEG activity was elicited by microinjection (5 µl) of 5% potassium chloride into the caudate nucleus (n = 7) or hippocampus (n = 3) during stereotactic brain surgery in patients with focal epilepsy. An electrode-cannula assembly for eliciting and recording the slow potential waves of SD is described. The parameters of SD in human brain are similar to those in lower mammals. Functional ablation by SD can be used as a diagnostic tool in neurosurgery.

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Section: Discussionsupporting

confidence: 63%

Functional Ablation by Spreading Depression: Possible Use in Human Stereotactic Neurosurgery

Šramka¹,

Brožek²,

Bureš³

et al. 1977

Stereotact Funct Neurosurg

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“…Yet we were not able to demonstrate any mechanism other than local tissue response for such a widespread effect. Though under some circumstances, localized injury to the cortex can result in slowly spreading effects (the spreading depression of Leao), the studies of Marshall and associates 19 have indicated that such effects spreading to a distance do not occur when the cortex is bathed in liquid petroleum at body temperature, as in all our experiments. We therefore have no direct information as to the mechanism of such spread of a locally vasodilating mechanism to neighbor¬ ing areas.…”

Section: Resultssupporting

confidence: 47%

Polarographic Study of Cerebral Collateral Circulation

Meyer¹

1954

Arch NeurPsych

119

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THE IMPORTANCE of collateral circulation in the brain has been evident since the observations of Astley Cooper on ligation of the common carotid artery in man 1 and ligation of the principal cerebral vessels in the dog.2It is also common neurological experience that there is considerable variation in capacity for adjustments in the cerebral circulation from one person to another, for carotid occlusion in one person may occur without symptoms, whereas the infarction of most of a cerebral hemisphere may follow in another. The anatomical explanation for this is, in part, the variation in size of the communicating arteries of the circle of Willis. Such variation of collateral circulation prompts the neurosurgeon to compress the carotid artery preoperatively as a test of collateral circulation before ligating this vessel. Recent experience with arteriography has shown that some persons may successfully survive for years without either one or the other carotid artery functioning, rarely without both. In later years episodes of cerebral ischemia occur as the collateral circulation becomes restricted by further vascular disease or by falls in the systemic blood pressure.3 Records (in man) of intravascular pressure at the distal end of the carotid artery, in the circle of Willis, and in the middle cerebral vessels seldom show a fall greater than 30 to 50% when the carotid artery is occluded.* Varying degrees of recovery in the first few days following occlusion of the smaller cerebral vessels are also seen frequently. Lack of compensation in some cases raises the question as to how much adjustment may be due to smaller anasto¬ moses on the surface of the brain, the importance of which has recently been emphasized,6 though their presence was known to the earlier anatomists.In order to obtain some information concerning the mechanisms underlying this compensation in collateral cerebral vessels and their site of action, we have sought a method of plotting the effectiveness of circulation in several areas of cortex at the same time. We have chosen the polarographic method of measuring local changes in tissue oxygénation (EPG), using multiple platinum electrodes, along the lines of the investigation of coronary occlusion by Sayen and co-workers.7

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“…Nevertheless, this was often related to species differences rather than structural and functional alterations of epileptic tissues because earlier reports had suggested that the gyrencephalic cortex of cats and monkeys is more resistant against SD than the lissencephalic cortex of rodents. 33 However, we found that rat and human chronically epileptic tissues were similarly resistant against SD. Consistently, recent clinical trials suggested that patients with hemorrhagic and ischemic stroke or brain trauma display SDs in vivo in a similar fashion to rodents.…”

Section: Discussionmentioning

confidence: 75%

Chronically Epileptic Human and Rat Neocortex Display a Similar Resistance Against Spreading Depolarization In Vitro

Maslarova

Alam

Reiffurth

et al. 2011

Stroke

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Background and Purpose-Experimental and clinical evidence suggests that prolonged spreading depolarizations (SDs) are a promising target for therapeutic intervention in stroke because they recruit tissue at risk into necrosis by protracted intracellular calcium surge and massive glutamate release. Unfortunately, unlike SDs in healthy tissue, they are resistant to drugs such as N-methyl-D-aspartate-receptor antagonists. This drug resistance of SD in low perfusion areas may be due to the gradual rise of extracellular potassium before SD onset. Brain slices from patients undergoing surgery for intractable epilepsy allow for screening of drugs, targeting pharmacoresistant SDs under elevated potassium in human tissue. However, network changes associated with epilepsy may interfere with tissue susceptibility to SD. This could distort the results of pharmacological tests. Methods-We investigated the threshold for SD, induced by a gradual rise of potassium, in neocortex slices of patients with intractable epilepsy and of chronically epileptic rats as well as age-matched and younger control rats using combined extracellular potassium/field recordings and intrinsic optical imaging. Results-Both age and epilepsy significantly increased the potassium threshold, which was similarly high in epileptic rat and human slices (23.6Ϯ2.4 mmol/L versus 22.3Ϯ2.8 mmol/L). Conclusions-Our results suggest that chronic epilepsy confers resistance against SD. This should be considered when human tissue is used for screening of neuroprotective drugs. The finding of similar potassium thresholds for SD in epileptic human and rat neocortex challenges previous speculations that the resistance of the human brain against SD is markedly higher than that of the rodent brain. (Stroke. 2011;42:2917-2922.)

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The relation of dehydration of the brain to the spreading depression of Leao

Cited by 28 publications

References 19 publications

Functional Ablation by Spreading Depression: Possible Use in Human Stereotactic Neurosurgery

Functional Ablation by Spreading Depression: Possible Use in Human Stereotactic Neurosurgery

Polarographic Study of Cerebral Collateral Circulation

Chronically Epileptic Human and Rat Neocortex Display a Similar Resistance Against Spreading Depolarization In Vitro

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