Asymmetry of pressure autoregulation after traumatic brain injury

2003 ◽  
Vol 99 (6) ◽  
pp. 991-998 ◽  
Author(s):  
Eric A. Schmidt ◽  
Marek Czosnyka ◽  
Luzius A. Steiner ◽  
Marcella Balestreri ◽  
Piotr Smielewski ◽  
...  
Keyword(s):  
Head Injuries ◽  
Cerebral Arteries ◽  
Brain Lesion ◽  
Fatal Outcome ◽  
Midline Shift ◽  
Content Type ◽  
Arterial Blood ◽  
Left And Right ◽  
The Brain ◽  
Fine Print

Object. The aim of this study was to assess the asymmetry of autoregulation between the left and right sides of the brain by using bilateral transcranial Doppler ultrasonography in a cohort of patients with head injuries. Methods. Ninety-six patients with head injuries comprised the study population. All significant intracranial mass lesions were promptly removed. The patients were given medications to induce sedation and paralysis, and artificial ventilation. Arterial blood pressure (ABP) and intracranial pressure (ICP) were monitored in an invasive manner. A strategy based on the patient's cerebral perfusion pressure (CPP = ABP − ICP) was applied: CPP was maintained at a level higher than 70 mm Hg and ICP at a level lower than 25 mm Hg. The left and right middle cerebral arteries were insonated daily, and bilateral flow velocities (FVs) were recorded. The correlation coefficient between the CPP and FV, termed Mx, was calculated and time-averaged over each recording period on both sides. An Mx close to 1 signified that slow fluctuations in CPP produced synchronized slow changes in FV, indicating a defective autoregulation. An Mx close to 0 indicated preserved autoregulation. Computerized tomography scans in all patients were reviewed; the side on which the major brain lesion was located was noted and the extent of the midline shift was determined. Outcome was measured 6 months after discharge. The left—right difference in the Mx between the hemispheres was significantly higher in patients who died than in those who survived (0.16 ± 0.04 compared with 0.08 ± 0.01; p = 0.04). The left—right difference in the Mx was correlated with a midline shift (r = −0.42; p = 0.03). Autoregulation was worse on the side of the brain where the lesion was located (p < 0.035). Conclusions. The left—right difference in autoregulation is significantly associated with a fatal outcome. Autoregulation in the brain is worse on the side ipsilateral to the lesion and on the side of expansion in cases in which there is a midline shift.

Subarachnoid hemorrhage—induced upregulation of the 5-HT1B receptor in cerebral arteries in rats

2003 ◽  
Vol 99 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Jacob Hansen-Schwartz ◽  
Natalie Løvland Hoel ◽  
Cang-Bao Xu ◽  
Niels-Aage Svendgaard ◽  
Lars Edvinsson
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Real Time ◽  
Cerebral Vasospasm ◽  
Cerebral Arteries ◽  
Specific Treatment ◽  
Content Type ◽  
Sequence Of Events ◽  
Arterial Blood ◽  
Receptor Phenotype ◽  
Fine Print

Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture—induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH. Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription—polymerase chain reaction (PCR). In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed. Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.

Neuronal damage in gerbils caused by intermittent forebrain ischemia

1999 ◽  
Vol 91 (5) ◽  
pp. 835-842 ◽  
Author(s):  
Takatoshi Sorimachi ◽  
Hiroshi Abe ◽  
Shigekazu Takeuchi ◽  
Ryuichi Tanaka
Keyword(s):  
Neuronal Damage ◽  
Cerebral Arteries ◽  
Ischemic Insult ◽  
Content Type ◽  
Ischemic Episode ◽  
Temporary Occlusion ◽  
Ischemic Depolarization ◽  
The Brain ◽  
Severe Ischemia ◽  
Fine Print

Object. The purpose of this study was to investigate the possibility of preventing cumulative neuronal damage after repetitive severe ischemia.Methods. The authors monitored ischemic depolarization in the gerbil hippocampus, which has recently been shown to be a good experimental model of the effects of brief ischemia on the brain, and evaluated neuronal damage in the CA1 subregion 7 days after the ischemic insult. In a single-ischemia paradigm, the results indicate that induction of ischemia-induced neuronal damage depended on the duration of ischemic depolarization. Neuronal damage can be detected in the CA1 subregion after a period of depolarization lasting 210 seconds. Using a double-ischemia paradigm in which the animals were subjected to two periods of ischemia, there was apparently no accumulation of neuronal damage from the first ischemic episode to the second, provided the duration of the first period of ischemic depolarization did not exceed 90 seconds. Neuronal damage accumulated when the duration of the first ischemia episode exceeded 90 seconds, regardless of the duration of the reperfusion interval between the two ischemic insults. Finally, when the ischemic insult was spread over four separate episodes, each lasting 90 seconds (with a reperfusion interval of 5 minutes), neuronal damage was not found when the total depolarization period was less than 420 seconds.Conclusions. The authors conclude that cumulative neuronal damage may be avoided by adopting an intermittent ischemia approach. The implications of these results for human surgery requiring temporary occlusion of the cerebral arteries are discussed.

Real-time detection of vascular occlusion and reperfusion of the brain during surgery by using infrared imaging

2002 ◽  
Vol 96 (5) ◽  
pp. 918-923 ◽  
Author(s):  
Joseph C. Watson ◽  
Alexander M. Gorbach ◽  
Ryszard M. Pluta ◽  
Ramin Rak ◽  
John D. Heiss ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Resolution ◽  
Real Time ◽  
Infrared Imaging ◽  
Cerebral Arteries ◽  
Infrared Camera ◽  
Collateral Flow ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Application of sensitive infrared imaging is ideally suited to observe blood vessels and blood flow in exposed organs, including the brain. Temporary vascular occlusion is an important part of neurosurgery, but the capacity to monitor the effects of these occlusions in real time is limited. In surgical procedures that require vascular manipulation, such as those involving aneurysms, arteriovenous malformations (AVMs), or tumors, the ability to visualize blood flow in vessels and their distribution beds would be beneficial. The authors recount their experience in the use of a sensitive (0.02°C), high-resolution (up to 50 µm/pixel) infrared camera with a rapid shutter speed (up to 2 msec/frame) for localizing cortical function intraoperatively. They observed high-resolution images of cerebral arteries and veins. The authors hypothesized that infrared imaging of cerebral arteries, performed using a sensitive, high-resolution camera during surgery, would permit changes in arterial flow to be be seen immediately, thus providing real-time assessment of brain perfusion in the involved vascular territory. Methods. Cynomolgus monkeys underwent extensive craniectomies, exposing the frontal, parietal, and temporal lobes. Temporary occlusions of the internal carotid artery and middle cerebral artery branches (30 events) were performed serially and were visualized with the aid of an infrared camera. Arteries and veins of the monkey brain were clearly visualized due to cooling of the exposed brain, which contrasted with blood within the vessels that remained at core temperature. Blood flow changes in vessels were seen immediately (< 1 second) in real time during occlusion and reopening of the vessels, regardless of the duration of the occlusion. Areas of decreased cortical blood flow rapidly cooled (−0.3 to 1.3°C) and reheated in response to reperfusion. Rewarming occurred faster in arteries than in the cortex (for a 20-minute occlusion, the change in temperature per second was 2 × 10−2°C in the artery and 7 × 10−3°C in the brain). Collateral flow could be evaluated by intraoperative observations and data processing. Conclusions. Use of high-resolution, digital infrared imaging permits real-time visualization of arterial flow. It has the potential to provide the surgeon with a means to assess collateral flow during temporary vessel occlusion and to visualize directly the flow in parent arteries or persistent filling of an aneurysm after clipping. During surgery for AVMs, the technique may provide a new way to assess arterial inflow, venous outflow, results of embolization, collateral flow, steal, and normal perfusion pressure breakthrough.

Gamma surgery for melanoma metastases in the brain

2002 ◽  
Vol 96 (3) ◽  
pp. 544-551 ◽  
Author(s):  
Vincenzo Mingione ◽  
Marcelo Oliveira ◽  
Dheerendra Prasad ◽  
Melita Steiner ◽  
Ladislau Steiner
Keyword(s):  
Brain Metastases ◽  
Survival Time ◽  
Cox Regression ◽  
Brain Lesion ◽  
High Dose ◽  
Content Type ◽  
Melanoma Metastases ◽  
The Brain ◽  
Fine Print

Object. The aim of this study was to evaluate the usefulness and limitations of gamma surgery (GS) in the treatment of brain metastases from melanoma. Methods. Imaging and clinical outcomes in 45 patients treated for 92 brain metastases from melanoma between October 1989 and October 1999 were retrospectively analyzed. Follow-up imaging studies were available in 35 patients with 66 treated lesions. Twenty-four percent of the lesions disappeared, 35% shrank, 23% remained unchanged, and 18% increased in size. No undue radiation-induced changes were observed in the surrounding brain. Clinical data were available in all patients. No deaths or neurological morbidity related to GS was observed. The median survival time, calculated using the Kaplan—Meier method, was 10.4 months from the time of GS. In both univariate and multivariate Cox regression analyses, a single brain lesion and lack of visceral metastases were statistically predictive of a better prognosis. Six of eight patients with solitary metastasis (that is, a single brain metastasis with no primary visceral tumor) were still alive at the close of the study, none of them with disease progression, with a follow-up period ranging between 14 and 82 months. Sixteen patients in this series received adjunctive whole-brain radiation therapy, which had no impact on their survival time or local and distant control of the brain disease. Conclusions. Gamma surgery is effective in treating melanoma metastases in the brain. It appears that the radiobiology of a single high dose overcomes the radioresistance barrier, yielding better results than fractionated radiation.

Cerebral aneurysms following radiotherapy for medulloblastoma

1989 ◽  
Vol 70 (4) ◽  
pp. 545-550 ◽  
Author(s):  
Peter J. Benson ◽  
Joo Ho Sung
Keyword(s):  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Content Type ◽  
Histological Features ◽  
Autopsy Examination ◽  
Cerebellar Medulloblastoma ◽  
Radiation Induced ◽  
The Brain ◽  
Fine Print ◽  
Saccular Aneurysms

✓ Three patients, two males and one female aged 21, 14, and 31 years, respectively, developed cerebral saccular aneurysms several years after undergoing radiotherapy for cerebellar medulloblastoma at 2, 5, and 14 years of age, respectively. Following surgery, all three received combined cobalt-60 irradiation and intrathecal colloidal radioactive gold (198Au) therapy, and died from rupture of the aneurysm 19, 9, and 17 years after the radiotherapy, respectively. Autopsy examination revealed no recurrence of the medulloblastoma, but widespread radiation-induced vasculopathy was found at the base of the brain and in the spinal cord, and saccular aneurysms arose from the posterior cerebral arteries at the basal cistern or choroidal fissure. The aneurysms differed from the ordinary saccular aneurysms of congenital type in their location and histological features. Their locations corresponded to the areas where intrathecally administered colloidal 198Au is likely to pool, and they originated directly from a segment of the artery rather than from a branching site as in congenital saccular aneurysms. It is, therefore, concluded that the aneurysms in these three patients were most likely radiation-induced.

Norepinephrine in cerebrospinal fluid of patients with cerebral vasospasm

1982 ◽  
Vol 56 (3) ◽  
pp. 344-349 ◽  
Author(s):  
Taku Shigeno
Keyword(s):  
Cerebrospinal Fluid ◽  
Cerebral Arteries ◽  
Cerebral Aneurysms ◽  
Fluorometric Method ◽  
Content Type ◽  
Highly Sensitive ◽  
Secondary Phenomenon ◽  
Lumbar Cerebrospinal Fluid ◽  
The Brain ◽  
Fine Print

✓ The content of norepinephrine (NE) in the ventricular, basal cisternal, and lumbar cerebrospinal fluid (CSF) was determined in 19 patients with ruptured cerebral aneurysms at different intervals according to the presence or absence of vasospasm. Twelve were operated on within 3 days after subarachnoid hemorrhage (SAH), prior to the occurrence of vasospasm. Postoperatively, CSF was continuously drained from a basal cistern or lateral ventricle. Norepinephrine was assayed by the highly sensitive automated fluorometric method. The concentration of NE increased in all sites of CSF sampling along with the appearance of vasospasm. Above all, the cisternal CSF of patients with vasospasm contained significantly higher NE (0.246 ± 0.049 ng/ml, mean ± SEM) compared to those without vasospasm (0.075 ± 0.001 ng/ml) (p < 0.001). However, since this increase cannot be considered to be high enough locally to constrict cerebral arteries, this might be only a secondary phenomenon due to release of NE into CSF from various sources in the brain.

The recurrent artery of Heubner: Otto Heubner's description of the artery and his influence on pediatrics in Germany

2000 ◽  
Vol 93 (6) ◽  
pp. 1084-1088 ◽  
Author(s):  
Raymond I. Haroun ◽  
Daniele Rigamonti ◽  
Rafael J. Tamargo
Keyword(s):  
Internal Medicine ◽  
Energy Metabolism ◽  
Cerebral Arteries ◽  
Early Research ◽  
Anterior Communicating Artery ◽  
Anatomical Studies ◽  
Content Type ◽  
Morphological Studies ◽  
The Brain ◽  
Fine Print

✓ Although the recurrent artery of Heubner is one of the best known cerebral arteries, little has been written in the neurosurgical or anatomical literature about its discovery. The artery is of primary importance to cerebrovascular surgeons, who identify it during clipping of anterior communicating artery aneurysms. Johann Otto Leonhardt Heubner (1843–1926), who described this artery in 1872, is better known as the father of German pediatrics. He was appointed to the first professorship in Germany exclusively devoted to pediatrics at the Charité Children's Clinic of Berlin University. Although he initially studied internal medicine in Leipzig under Carl Reinhold August Wunderlich and Ernst Leberecht Wagner, his early research involved anatomical studies of the circulation of the brain, from which he described syphilitic endarteritis (Heubner's disease). Finding morphological studies inconclusive, he turned to more physiological experiments. Together with the physiologist Max Rubner, Heubner performed important studies on energy metabolism in infancy, creating the notion of the nutrition quotient. In this article the authors review Heubner's life and scientific discoveries.

Comparison of middle cerebral artery trunk occlusion by silicone cylinder embolization and by trapping

1983 ◽  
Vol 58 (4) ◽  
pp. 492-499 ◽  
Author(s):  
Yoshikazu Okada ◽  
Takeshi Shima ◽  
Noboru Yokoyama ◽  
Tohru Uozumi
Keyword(s):  
Cerebral Infarction ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Clinicopathological Features ◽  
Neurological Deficits ◽  
Midline Shift ◽  
Content Type ◽  
Chronic Stage ◽  
The Brain ◽  
Fine Print

✓ The authors produced occlusion of the middle cerebral artery (MCA) trunk in dogs by two methods: silicone cylinder embolization and trapping. Comparative analyses of the clinicopathological features in these models, extending from the acute to chronic stage, were performed. Within 24 hours after embolization, the brain exhibited swelling without macroscopic infarction. Microangiograms revealed impaired filling in the deep areas of the brain with midline shift. At 4 to 7 days after embolization, the animals showed major neurological deficits, evident deep cerebral infarction, and poorly perfused areas in the deep cerebrum with prominent midline shift. At 3 to 4 weeks after embolization, the neurological deficits improved and the affected regions showed cavities or localized lesions. Microangiograms demonstrated hypervascular areas with abnormal vessels in the affected cerebrum. On the other hand, trapping of the MCA trunk produced mild neurological deficits, although there was no evidence of macroscopic lesions or impairment of filling. This study shows that silicone cylinder embolization in the MCA trunk produces a reliable and reproducible deep cerebral infarction in dogs.

The treatment of penetrating wounds of the brain sustained in warfare

1974 ◽  
Vol 40 (2) ◽  
pp. 157-167 ◽  
Author(s):  
E. Stephen Gurdjian
Keyword(s):  
Head Injuries ◽  
Penetrating Wounds ◽  
Content Type ◽  
Modern Times ◽  
History Of ◽  
The Brain ◽  
Fine Print

✓ The author reviews the history of the management of head injuries with particular emphasis on penetrating wounds from antiquity to modern times. He traces the influence of gunpowder weaponry and early instrumentation on the development of treatments.

Delayed neurological deterioration following resection of arteriovenous malformations of the brain

1999 ◽  
Vol 90 (4) ◽  
pp. 695-701 ◽  
Author(s):  
Michael K. Morgan ◽  
Lali H. S. Sekhon ◽  
Simon Finfer ◽  
Verity Grinnell
Keyword(s):  
Arteriovenous Malformations ◽  
Cerebral Arteries ◽  
Venous Drainage ◽  
Neurological Deficits ◽  
Grading System ◽  
Content Type ◽  
Drainage Networks ◽  
Middle Cerebral Arteries ◽  
The Brain ◽  
Fine Print

Object. The aim of this study was to analyze delayed neurological deficits following surgical resection of arteriovenous malformations (AVMs).Methods. The authors report on a consecutive series of 200 patients with angiographically proven AVMs of the brain that were surgically resected between January 1989 and June 1998. The 30-day mortality rate for patients in this series was 1%, with one death caused by AVM resection and one death attributed to basilar artery aneurysm repair following successful AVM resection. The Spetzler—Martin grading system correlated well with the difficulty of surgery. No permanent incidence of morbidity resulted from resection of Grade I or II AVMs; the percentage of patients with a significant neurological deficit due to resection was 7.8% for those with Grade III lesions and 33.3% for those with Grade IV or V AVMs. However, this grading system did not accurately predict the development of delayed neurological deficits.Ten patients (5%) developed delayed neurological deficits after recovering from anesthesia and surgery. The delayed deficit was due to hemorrhage in four of the 10 patients and all four had undergone resection of AVMs measuring at least 4 cm in diameter. An increase in blood pressure during the first 8 postoperative days precipitated hemorrhage in these patients. Edema arising as a consequence of propagated venous thrombosis (two patients) was associated with extensive venous drainage networks rather than large AVM niduses. Both hemorrhagic and edematous complications can be included under the umbrella term of “arterial-capillary-venous hypertensive syndrome” to describe the common underlying pathogenesis accurately. An additional four patients developed a delayed deficit as a result of vasospasm. Vasospasm occurred when resection had involved extensive dissection of proximal anterior and middle cerebral arteries; in such cases the incidence of vasospasm was 27%.Conclusions. On the basis of their analysis of these complications, the authors recommend strict blood pressure control for patients with lesions measuring 4 cm or more in diameter (particularly those with a deep arterial supply). Thromboprophylaxis with aspirin and heparin is prescribed for patients with extensive venous drainage networks, and prophylactic nimodipine therapy and angiographic surveillance for vasospasm are suggested for patients in whom extensive dissection of proximal anterior or middle cerebral arteries has been necessary.

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