scholarly journals STUDIES ON INTRACRANIAL PRESSURE

1909 ◽  
Vol 11 (3) ◽  
pp. 489-514 ◽  
Author(s):  
J. A. E. Eyster ◽  
M. T. Burrows ◽  
C. R. Essick

1. The results of this work form a confirmation of the earlier work of Cushing in all details investigated. 2. The increase of blood pressure that results from an increase of the intracranial pressure above the blood pressure is due in the dog to a vaso-constriction of the vessels of the intestine, the kidney and the limbs. Preceding this constriction there is dilatation. 3. The anastomotic connection between the internal carotid artery within the skull and the ophthalmic branch of the internal maxillary is of a size in the dog approximately equal to the internal carotid outside of the skull. The anatomical relations are such as to indicate that the internal maxillary artery in this animal is a cerebral artery equal in importance to the internal carotid. The anastomotic connection because of its position within the cranial cavity is unaffected except by extreme grades of intracranial compression. 4. The ordinary method of artificial perfusion of the dog's brain as used in physiological investigation appears from this work to be of no value, since there is at least one important path open besides that through the vessels of the brain. 5. The increase of the intracranial pressure above the blood pressure leads to a complete anæmia, superficial and deep, of the blood vessels of the brain. If the intracranial pressure is not greatly increased above the blood pressure, the circle of Willis and some of the larger arterial connections at the base of the brain are more or less well injected. An intracranial pressure somewhat below blood pressure leads apparently to a certain degree of anæmia directly beneath the point of entrance of the intracranial fluid; the condition of the rest of the brain as regards blood supply is normal.

2021 ◽  
Vol 8 (29) ◽  
pp. 2639-2643
Author(s):  
Sruthy Unni ◽  
Ranju Sebastian ◽  
Elizabeth Joseph ◽  
Remani Kelan Kamalakshi ◽  
Jamsheena Muthira Parambath

BACKGROUND Anaesthesia for neurosurgery requires special considerations. The brain is enclosed in a rigid cranium, so the rise in intracranial pressure (ICP) which impairs cerebral perfusion pressure (CPP), results in irrepairable damage to various vital areas in the brain. Stable head position is required in long neurosurgical procedures. This is obtained with the use of clamps which fix the head rigidly. This is done usually under general anaesthesia because it produces intense painful stimuli leading to stimulation of sympathetic nervous system which in turn causes release of vasoconstrictive agents. This can impair perfusion in all organ systems. The increase in blood pressure due to sympathetic nervous system causes increase in blood flow. This causes increases in intracranial pressure which result in reduction in cerebral perfusion pressure once the auto regulatory limits are exceeded. We compared the effects of dexmedetomidine 1 µgm/kg and propofol 100 µgm/kg given as infusion over a period of 10 minutes before the induction of anaesthesia and continued till 5 minutes after pinning to attenuate the stress response while cranial pinning. In this study, we wanted to compare the effects of dexmedetomidine and propofol as infusion to attenuate the stress response while cranial pinning in patients undergoing neurosurgical procedures. METHODS This is a randomized interventional trial. Patients were divided into 2 groups of 20 each. Group 1 receiving dexmedetomidine and group 2 receiving propofol, both drugs given as infusion. Haemodynamic variables were monitored before and after cranial pinning. Data was analysed using IBM statistical package for social sciences (SPSS) statistics. The parameters recorded were analysed with the help of a statistician. RESULTS The two groups were comparable in demographic data. Incidence of tachycardia between group 1 and 2 showed that tachycardia to pinning was better controlled with propofol than dexmedetomidine (P < 0.05) which is statistically significant. There is no statistically significant difference in blood pressure values between group 1 and 2 after pinning. CONCLUSIONS From our study, we came to a conclusion that propofol was superior to dexmedetomidine in attenuating the heart rate response to cranial pinning. The effect of propofol and dexmedetomidine was comparable in attenuating the blood pressure response to cranial pinning. KEYWORDS Cranial Pinning, Dexmedetomidine, Propofol


1960 ◽  
Vol 39 (6) ◽  
pp. 1141-1145 ◽  
Author(s):  
D.R. Redden ◽  
J.G. Bishop ◽  
J.L. Matthews ◽  
H.L. Dorman

1999 ◽  
Vol 23 (1) ◽  
pp. 59-66
Author(s):  
Khalid Kamil Kadhum

The brain of the sheep receives its blood supply through the carotid rete and the basilar artery. The carotid rete formed of contribution of internal carotid artery and branches from maxillary artery. The internal carotid artery courses on the ventral surface of the cerebal crus to give the rostral cerebal artery and the caudal communicating artery . Thus , arteries excepted the middle cerebal artery forming with the same arteries of the opposite side , the cerebal arterial circle or circle of Willis. The internal caroted artery also gives off hypophysialartery to the  1999 ind, (1) swell, ügymielly wel dati', il pellilendiambell ileti  hypophysis. The caudal communicating artery give off the caudal cerebal artery and the rostral cerebellar artery and unite with the corresponding artery of the opposite side to form the basilar artery rostral to the pone . The basilar artery gives off the pontine artery , caudal cerebellar artery and the medullary branch. 


1977 ◽  
Vol 232 (5) ◽  
pp. H495-H499
Author(s):  
M. Manrique ◽  
E. Alborch ◽  
J. M. Delgado

Cerebral blood flow, heart rate, arterial blood pressure, and behavior were studied in conscious goats during electrical stimulation of the diencephalon and mesencephalon. Stimulation of the subthalamic area produced a considerable increase in ipsilateral cerebral blood flow and heart rate, accompanied by either a small or a large increase in systemic arterial blood pressure. Cardiovascular effects were associated with changes in alertness. The increase in cerebral blood flow was partially abolished by previous administration of atropine directly into the internal maxillary artery. Stimulation of the mesencephalic reticular formation caused a marked increase in blood pressure with no change or with some decrease in cerebral blood flow. After administration of phentolamine into the internal maxillary artery, stimulation produced increase in cerebral blood flow. The behavioral response consisted of restlessness and attempted flight. These results suggest the existence of cholinergic vasodilator and adrenergic vasoconstrictor pathways to cerebral blood vessels that may be stimulated electrically.


1972 ◽  
Vol 37 (6) ◽  
pp. 695-699 ◽  
Author(s):  
Timo Kuurne ◽  
Henry Troupp

✓ Hydrostatic pressure with artificial cerebrospinal fluid (CSF) was applied through a needle inserted into the cisterna magna of rabbits breathing spontaneously. Blood pressure, confluens sinuum pressure and oxygen tension, respiratory rate and volume, and acid-base balance were recorded until respiratory arrest. Blood pressure and confluens sinuum pressure and respiratory volume rose; confluens sinuum oxygen and arterial carbon dioxide tension dropped. The significant similarities and differences in changes in the same parameters following local cold injury to the brain are discussed. Comparisons between different experimental models for raised intracranial pressure must take into consideration the differing reactions of the brain.


1975 ◽  
Vol 38 (5) ◽  
pp. 942-945 ◽  
Author(s):  
D. J. Miletich ◽  
A. D. Ivankovic ◽  
R. F. Albrecht ◽  
E. T. Toyooka

Changes in cerebral and extracerebral blood flow in the goat after ligation of the internal maxillary artery and deliberate thrombosis of the extracerebral arteries (buccinator, ethmoidal, and ophthalmic) with thrombin were compared to changes seen in animals after internal maxillary artery ligation only and in normal animals where no surgical manipulations were performed. Blood flow was measured by injecting 51-Cr-labeled microspheres into the internal maxillary artery via a catheter placed into the temporal artery. Analysis of the radioactivity in extracerebral and intracerebral tissues indicated that when the internal maxillary artery is ligated and the extracerebral arteries are thrombosed, virtually all of the blood flow from the carotid artery is destined from the brain. However, if only the internal maxillary artery is ligated nearly one-fourth of the blood flow from the maxillary travels to extra-cerebral tissues. In normal animals, it was determined that only one-fourth of the blood flow in the internal maxillary is destined for the cerebral circulation. Results from this study indicate that if the former method is employed an accurate measure of cerebral blood flow is possible without the complications of extra-cerebral flow. If the latter technique is used care must be taken in evaluating cerebral blood flow since a large component of extra-cerebral blood flow is present.


1972 ◽  
Vol 36 (5) ◽  
pp. 625-633 ◽  
Author(s):  
Markku Kaste ◽  
Henry Troupp

✓ Changes in the blood pressure, cerebral sinus pressure, cerebral venous oxygen tension, acid-base balance, respiratory frequency, and respiratory minute volume were studied in the rabbit after a lethal cold injury to the brain. About half of the animals responded to the injury with a quick rise in cerebral sinus pressure and in its relation to blood pressure (CSP/BP); in the other half, cerebral sinus pressure and the CSP/BP ratio rose more slowly. Changes in the CSP/BP ratio correlated well with criteria for changes in respiratory performance. The changes in cerebral venous oxygen tension were reasonably uniform: a dip during freezing, an overshoot to a mean of 1.6 times the original level (about 30 mm Hg) immediately after injury, a gradual return to the pretraumatic level, and then a drop to lower levels. The brain injury led to a respiratory alkalosis that became more pronounced the longer the animals lived. Considered with CSP/BP ratio, respiratory reaction to the brain injury may provide an early and accurate prognosis. The fact that at the time of death the cerebral perfusion pressure was still within a range believed safe for the brain shows that an actual brain injury, in addition to raised intracranial pressure, is important in such experiments and emphasizes the inappropriateness of comparing levels of intracranial pressure raised by a variety of methods.


This work records an investigation of the anatomy of the cranial blood supply in various species of mammal. The findings were based on a study of radiographs of specimens injected with a radioopaque mass and of casts of the vessels made by injection of neoprene latex, and on dissections of injected preparations. A well-developed carotid rete was found to be present in the cat, sheep, goat, ox and pig, and a rudimentary form of this structure was found in the dog. In the cat the rete is situated extracranially, but in the other species it lies within the cranium in the cavernous sinus. There is no carotid rete in the rabbit or the rat. The carotid rete consists of a compact network of intertwined, freely anastomosing arteries, and is related to the branches of the trigeminal nerve. When the rete is situated intracranially there is a variable degree of communication across the mid-line with the rete of the opposite side. W hether situated intracranially or extracranially the rete lies within a venous lake. The presence of a well-developed carotid rete was associated with the non-persistence of, or a degenerating internal carotid artery. A thin fibrous cord was the only rem nant of this artery found in the cat. In the goat, sheep and pig the internal carotid artery was absent proximal to the rete, but the large trunk which connected the rete with the circle of Willis was identified as representing the still persisting distal segment of this artery. In the ox (a young animal) a similar trunk connecting the rete with the circle of Willis formed the continuation of a still persisting but relatively narrow proximal segment of the internal carotid artery. The main vessels which may supply the carotid rete are the internal maxillary artery (usually via the ramus anastomoticus and the arteria anastomotica), the ascending pharyngeal artery, and the occipital artery. In the cat, sheep, goat and ox the chief vessel of supply is the internal maxillary artery, but in the pig it is the ascending pharyngeal artery. In the ox a substantial contribution is provided by the occipital artery. Both the ramus anastomoticus and the arteria anastomotica form connexions between the external and internal carotid systems and they join one another within the cavernous sinus. It is at his site that the intracranial carotid rete is developed, but the extracranial carotid rete, seen in the cat, is situated around the internal maxillary artery at the site of origin of the arteria anastomotica of the artiodactyls. The variations in the situation of the carotid rete in different species is along the line of the arteria anastomotica. It is suggested that the arteria anastomotica and the ramus anastomoticus respectively are homologous with the recurrent meningeal and the middle meningeal arteries of the rabbit and man. The arteries which supply the orbital and the ethmoidal regions are described and the homologies of the external ophthalmic artery are discussed. The great variability in the supply of these territories which was seen in the cat is thought to be associated with the presence of an extracranial carotid rete. In spite of variations in different species of animal a basic pattern can be discerned in the major arteries supplying the head. It is suggested that this basic pattern is related to a primitive stapedial artery, and that the variations seen are due to modifications of the branches of this earlier vessel. The circle of Willis was found to derive its blood supply from one or more of five sources: the internal carotid artery, the external carotid arterial system, the ascending pharyngeal artery, the vertebral artery (via the basilar artery) and the occipital artery. In the absence of an internal carotid artery the greatest contribution of blood passes to the circle of Willis through the carotid rete. An occipito-vertebral anastomosis seems to be of some importance in supplying the circle of Willis in the cat, pig, dog and rabbit. In the sheep, goat and ox the direction of the flow of blood in the basilar artery would appear to be away from and not towards the circle of Willis. In the pig the two anterior cerebral arteries anastomose in the mid-line and continue forward as a single vessel. The peculiar structure of the vessels which compose the carotid rete suggests that this compact network has a haemodynamic significance, and since the rete lies in the pathway of the major artery or arteries which supply the brain, its existence and possible influence should be borne in mind when problems of the cerebral circulation are considered in species in which this structure is present.


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