Changes in extracellular potassium concentration in cortex and brain stem during the acute phase of experimental closed head injury

1981 ◽  
Vol 55 (5) ◽  
pp. 708-717 ◽  
Author(s):  
Hiroshi Takahashi ◽  
Shinya Manaka ◽  
Keiji Sano
Keyword(s):  
Blood Pressure ◽  
Brain Stem ◽  
Low Voltage ◽  
Potassium Concentration ◽  
Control Level ◽  
Extracellular Potassium ◽  
Content Type ◽  
The Impact ◽  
The Brain ◽  
Fine Print

✓ A high potassium concentration ([K+]o) in brain tissue impedes neuronal activity, as observed in spreading cortical depression. Experimental studies were performed on mice and rats to determine the role of changes of [K+]o in cerebral concussion. In the first experiment, a 600 gm-cm impact was delivered to the vertex of the mouse skull. This impact induced arrest of spontaneous movement for 465 ± 55.9 seconds (mean ± SD), accompanied by apnea, bradycardia, and low-voltage electroencephalographic recordings (EEG). The injury was also frequently followed immediately by epilepsy. This impact induced an increase of cortical [K+]o from the control level of 4.1 ± 1.8 mM to 20–30 mM, with gradual recovery within 30 minutes to the control level. In the second experiment, an impact of 9000 gm-cm was delivered to the midline parieto-occipital area of the rat and produced concussion-like phenomena similar to those elicited in mice. This level of trauma induced a significant increase of cortical [K+]o from the control level of 4.2 ± 0.8 mM to 20–50 mM in all of the rats, and also a significant increase of brain-stem [K+]o from 3.9 ± 0.6 to 20–30 mM in 73% of the rats. In these latter rats, the impact also induced apnea and a transient elevation of blood pressure, and resulted in low-voltage EEG recordings. In 23% of the rats in which [K+]o changes in the brain stem were not significant, the impact caused a transient reduction of blood pressure. The present study disclosed that an increase of [K+]o in the cerebral cortex and also in the brain stem is an important element in the phenomenon of concussion.

Arteriovenous malformations in the posterior fossa

1977 ◽  
Vol 47 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Hiroshi Matsumura ◽  
Yasumasa Makita ◽  
Kuniyuki Someda ◽  
Akinori Kondo
Keyword(s):  
Arteriovenous Malformation ◽  
Brain Stem ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Cerebellopontine Angle ◽  
Anterior Part ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ We have operated on 12 of 14 cases of arteriovenous malformation (AVM) in the posterior fossa since 1968, with one death. The lesions were in the cerebellum in 10 cases (three anteromedial, one central, three lateral, and three posteromedial), and in the cerebellopontine angle in two; in two cases the lesions were directly related to the brain stem. The AVM's in the anterior part of the cerebellum were operated on through a transtentorial occipital approach.

Cerebral oxygen and microdialysis monitoring during aneurysm surgery: effects of blood pressure, cerebrospinal fluid drainage, and temporary clipping on infarction

2002 ◽  
Vol 96 (6) ◽  
pp. 1013-1019 ◽  
Author(s):  
Rupert Kett-White ◽  
Peter J. Hutchinson ◽  
Pippa G. Al-Rawi ◽  
Marek Czosnyka ◽  
Arun K. Gupta ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cerebrospinal Fluid ◽  
Brain Tissue ◽  
Total Duration ◽  
Wilcoxon Test ◽  
Fisher Exact Test ◽  
Content Type ◽  
The Impact ◽  
Temporary Clipping ◽  
Fine Print

Object. The aim of this study was to investigate potential episodes of cerebral ischemia during surgery for large and complicated aneurysms, by examining the effects of arterial temporary clipping and the impact of confounding variables such as blood pressure and cerebrospinal fluid (CSF) drainage. Methods. Brain tissue PO2, PCO2, and pH, as well as temperature and extracellular glucose, lactate, pyruvate, and glutamate were monitored in 46 patients by using multiparameter sensors and microdialysis. Baseline data showed that brain tissue PO2 decreased significantly, below a mean arterial pressure (MAP) threshold of 70 mm Hg. Further evidence of its relationship with cerebral perfusion pressure was shown by an increase in mean brain tissue PO2 after drainage of CSF from the basal cisterns (Wilcoxon test, p < 0.01). Temporary clipping was required in 31 patients, with a mean total duration of 14 minutes (range 3–52 minutes), causing brain tissue PO2 to decrease and brain tissue PCO2 to increase (Wilcoxon test, p < 0.01). In patients in whom no subsequent infarction developed in the monitored region, brain tissue PO2 fell to 11 mm Hg (95% confidence interval 8–14 mm Hg). A brain tissue PO2 level below 8 mm Hg for 30 minutes was associated with infarction in any region (p < 0.05 according to the Fisher exact test); other parameters were not predictive of infarction. Intermittent occlusions of less than 30 minutes in total had little effect on extracellular chemistry. Large glutamate increases were only seen in two patients, in both of whom brain tissue PO2 during occlusion was continuously lower than 8 mm Hg for longer than 38 minutes. Conclusions. The brain tissue PO2 decreases with hypotension, and, when it is below 8 mm Hg for longer than 30 minutes during temporary clipping, it is associated with increasing extracellular glutamate levels and cerebral infarction.

Cervical spinal cord in experimental hydrocephalus

1972 ◽  
Vol 37 (5) ◽  
pp. 538-542 ◽  
Author(s):  
George J. Dohrmann
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
Central Canal ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Physiological Pressure ◽  
The Brain ◽  
Shunting Procedure ◽  
Fine Print

✓ Adult dogs were rendered hydrocephalic by the injection of kaolin into the cisterna magna. One group of dogs was sacrificed 1 month after kaolin administration, and ventriculojugular shunts were performed on the other group. Hydrocephalic dogs with shunts were sacrificed 1 day or 1 week after the shunting procedure. All dogs were perfused with formalin at physiological pressure, and the brain stem and cervical spinal cord were examined by light microscopy. Subarachnoid granulomata encompassed the superior cervical spinal cord and dependent surface of the brain stem. Rarefaction of the posterior white columns and clefts or cavities involving the gray matter posterior to the central canal and/or posterior white columns were present in the spinal cords of both hydrocephalic and shunted hydrocephalic dogs. Predominantly in the dogs with shunts, hemorrhages were noted in the spinal cord in association with the clefts or cavities. A mechanism of ischemia followed by reflow of blood is postulated to explain the hemorrhages in the spinal cords of hydrocephalic dogs with shunts.

Cerebral cysticercosis with aqueductal obstruction

1980 ◽  
Vol 53 (2) ◽  
pp. 252-255 ◽  
Author(s):  
Tung Pui Poon ◽  
Edward J. Arida ◽  
Wolodymyr P. Tyschenko
Keyword(s):  
Intracranial Hypertension ◽  
Brain Stem ◽  
Normal Pressure Hydrocephalus ◽  
Signs And Symptoms ◽  
Normal Pressure ◽  
Content Type ◽  
Neurological Signs ◽  
Cerebral Cysticercosis ◽  
The Brain ◽  
Fine Print

✓ The authors report a case of cerebral cysticercosis which presented with generalized nonspecific neurological signs and symptoms attributed to acute aqueductal obstruction, with concomitant intracranial hypertension. These were characteristic intracranial calcifications along with angiographically demonstrated signs of hydrocephalus. Contrast encephalography clearly demonstrated aqueductal obstruction. Pathologically, the aqueductal obstruction was shown to be due to parasitic invasion of the brain stem with compression of the aqueduct. The presence of typical intracranial calcification in conjunction with either obstructive or normal-pressure hydrocephalus should alert the observer to the possibility of cerebral cysticercosis.

Odontoid compression of the brain stem in a patient with rheumatoid arthritis

1980 ◽  
Vol 53 (6) ◽  
pp. 841-845 ◽  
Author(s):  
Harold P. Smith ◽  
Venkata R. Challa ◽  
Eben Alexander
Keyword(s):  
Rheumatoid Arthritis ◽  
Brain Stem ◽  
Neurological Deficit ◽  
Neurological Symptoms ◽  
Direct Compression ◽  
Content Type ◽  
Vertical Subluxation ◽  
Progressive Neurological Deficit ◽  
The Brain ◽  
Fine Print

✓ Cervical spine involvement by rheumatoid arthritis is common; brain-stem compression secondary to vertical subluxation of the odontoid in patients with rheumatoid arthritis is rare. Vertical subluxation results from 1) destruction of the transverse atlantal, apical, and alar ligaments of the atlas and odontoid, and 2) bone resorption in the occipital condyles, lateral masses of the atlas, and basilar processes of the skull. Neurological symptoms result from direct compression of the brain stem or from ischemia secondary to compression of vertebral arteries, anterior spinal arteries, or small perforating arteries of the brain stem and spinal cord. A case is reported in which a slowly progressive neurological deficit developed in a woman with rheumatoid arthritis following a fall from a stretcher. Neurological symptoms represented direct compression of the medulla by the dens, a mechanism confirmed at operation and autopsy. Recognition of progressive neurological deficit is often difficult in patients with rheumatoid arthritis because of their inactivity and their atrophic and immobile joints, but is essential if appropriate decompressive or stabilizing procedures are to be done. In patients with vertical subluxation of the dens, the transoral approach with removal of the odontoid is recommended. Decompression should be extensive, including the fibrous capsule around the odontoid and overlying synovial tissue as well as the odontoid itself.

Vascular malformations of the brain stem

1989 ◽  
Vol 70 (6) ◽  
pp. 847-852 ◽  
Author(s):  
Douglas Chyatte
Keyword(s):  
Brain Stem ◽  
Vascular Malformation ◽  
Vascular Malformations ◽  
Surgical Removal ◽  
Content Type ◽  
Appropriate Treatment ◽  
Complete Obliteration ◽  
Time Of Presentation ◽  
The Brain ◽  
Fine Print

✓ Vascular malformations of the brain stem are unusual lesions that may pose a diagnostic and therapeutic challenge. Seven patients with vascular malformations involving the brain stem were evaluated; six were treated surgically, with complete obliteration of the lesion in five patients. In five patients symptoms developed only after a hemorrhage had occurred, and three of these suffered a rebleed before appropriate treatment was given. Angiography failed to demonstrate lesions in three cases, which did not appear to protect from repeat hemorrhage since two of the three rebled. There were no operative deaths, and no patients were made permanently worse after surgery. Useful recovery occurred commonly after appropriate treatment and appeared to be possible even in patients who had suffered a catastrophic neurological deficit at the time of presentation. These data indicate that surgical removal of the lesion may be warranted in some patients with symptomatic brain-stem vascular malformation.

Chemotherapy for malignant gliomas

1988 ◽  
Vol 68 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Paul L. Kornblith ◽  
Michael Walker
Keyword(s):  
Clinical Management ◽  
Malignant Gliomas ◽  
New Agents ◽  
Specific Patient ◽  
Content Type ◽  
Number Of Patients ◽  
New Findings ◽  
The Impact ◽  
The Brain ◽  
Fine Print

✓ There continues to be an extensive effort to develop chemotherapeutic approaches to the treatment of malignant gliomas of the brain. In the past 5 years there have been literally hundreds of trials of new agents, combinations of old and new agents, and even new routes and approaches to the delivery of chemotherapy. In this review, the literature has been studied and the individual reports analyzed to evaluate the impact of the new findings on clinical management of the patient with malignant glioma of the brain. The major areas of progress include the addition of new drugs with varying modes of action, the use of combinations of drugs in a synergistic fashion, and the development of new routes of drug delivery. None of the advances has brought about the revolution in clinical care that is so eagerly sought, but clearly the amount of new knowledge gained by these studies helps in understanding how to use chemotherapy more effectively. Furthermore, the remarkable degree of interest and involvement in the use of chemotherapy promises that an even greater number of patients with malignant gliomas will be considered for vigorous and enthusiastic clinical management programs even if chemotherapy itself is not the key modality in the treatment of a specific patient.

Primary carcinoma of the pituitary with metastasis to the brain stem

1972 ◽  
Vol 36 (6) ◽  
pp. 781-784 ◽  
Author(s):  
Alan S. Fleischer ◽  
Thomas Reagan ◽  
Joseph Ransohoff
Keyword(s):  
Brain Stem ◽  
Primary Carcinoma ◽  
Microscopic Appearance ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ A case of primary carcinoma of the pituitary with metastasis to the brain stem is presented. Although both tumors had the microscopic appearance of benign adenomas, the infiltrative characteristics necessitated the diagnosis of carcinoma.

Noninvasive localization of brain-stem lesions in the cat with multimodality evoked potentials

1981 ◽  
Vol 54 (6) ◽  
pp. 740-750 ◽  
Author(s):  
Richard P. Greenberg ◽  
Donald M. Stablein ◽  
Donald P. Becker
Keyword(s):  
Evoked Potentials ◽  
Brain Stem ◽  
Evoked Potential ◽  
Animal Experiments ◽  
Content Type ◽  
Central Nervous System Dysfunction ◽  
Multimodality Evoked Potentials ◽  
Stem Lesions ◽  
The Brain ◽  
Fine Print

✓ Multimodality evoked potential (MEP) data from over 300 comatose head-injured patients suggest that central nervous system dysfunction of the brain stem and/or hemispheres can be localized with this noninvasive neuroelectric technique. Based on this work, decerebrate motor posturing and prolonged coma are not associated with brain-stem dysfunction but rather with dysfunction of the hemispheres, while absent pupillary and oculocephalic responses are correlated with brain-stem dysfunction alone. However, the accuracy with which MEP data localized human brain-stem or hemispheric dysfunction could not be confirmed by pathological correlation because of low mortality and the small number of autopsies obtained in the patients who died. Therefore, this study was undertaken in an animal model of brain-stem lesion. Complete brain-stem transections were made at the cervicomedullary junction, the medulla just caudal to the eighth nerve, and at the intercollicular region. All cortical visual evoked potential (VEP) peaks were reduced in amplitude and delayed by each of the brain-stem transections, but none of the peaks was abolished. In spite of brain-stem transection, VEP's can be used to gain information about hemispheric function. Somatosensory (SEP) and auditory cortically generated evoked potentials (AEP) were abolished by these brain-stem transections, but early-latency brain-stem SEP and AEP data could accurately localize specific areas of brain-stem dysfunction caused by the lesions. Observations made on human MEP data seem to be confirmed by these animal experiments. Correlations between human and cat MEP data are discussed.

Trigeminal artery and microemboli to the brain stem

1977 ◽  
Vol 46 (1) ◽  
pp. 104-106 ◽  
Author(s):  
Frederick T. Waller ◽  
Robert L. Simons ◽  
Charles Kerber ◽  
Ilmar O. Kiesel ◽  
Calvin T. Tanabe
Keyword(s):  
Brain Stem ◽  
Atherosclerotic Plaque ◽  
Carotid Bifurcation ◽  
Persistent Trigeminal Artery ◽  
Transient Ischemic Attacks ◽  
Trigeminal Artery ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ The authors report two cases of transient ischemic attacks (TIA's) involving the brain stem. The TIA's were due to microemboli that originated from a carotid bifurcation atherosclerotic plaque and travelled through a persistent trigeminal artery.

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