bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of intracranial pressure on bridging veins in rats
Authors: Auer Ludwig M. , Ishiyama Norio , Hodde Kees C. , Kleinert Reinhold , Pucher Robert
Published: May 2009

✓ The behavior of bridging veins at their entrance into the superior sagittal sinus during elevated intracranial pressure (ICP) was investigated in rats using a cranial window and infusion of mock cerebrospinal fluid. The bridging veins became slightly smaller as the ICP rose (maximum reduction 17%). Compression or collapse of the veins was not observed, even at an ICP level of 100 mm Hg, and there was no cuffing of bridging veins upstream of the entrance. Both the scanning electron microscopic investigation based on resin vessel casts and the histological examination of whole-head coronal sections indicated that the narrowest points of the bridging veins are at their entrance to the superior sagittal sinus, caused by the oval aperture with thickened wall structure in the lateral sinus wall to which the bridging veins are connected. The present data thus support the concept that cerebral blood flow during intracranial hypertension is not reduced by venous cuffing or compression of the lateral lacunae and bridging veins; by contrast, the arteriovenous pressure difference seems to remain the determining factor even at high ICP. Thus, blood flow through the brain stops when ICP approaches the level of blood pressure.
Beagle pup model of brain injury: regional cerebral blood flow and cerebral prostaglandins
Authors: Ment Laura R. , Stewart William B. , Duncan Charles C. , Pitt Bruce R. , Cole Judith
Published: May 2009

✓ Asphyxia is the most common cause of severe brain injury in very young children, and frequently results in lesions of the periventricular white matter in addition to other neuropathological changes. This study examines the effects of asphyxia on regional cerebral blood flow (rCBF) and the role of prostaglandins (PG's) in its control in the newborn beagle pup. Pups were anesthetized, tracheotomized, paralyzed, artificially ventilated, and randomly assigned to two groups: asphyxial insult produced by discontinuing ventilatory support, and no insult. Experiments for carbon-14-iodoantipyrine autoradiographic determination of rCBF and regional cerebral PG determination were performed on separate groups of pups. These studies demonstrated a significant increase in cortical gray PGE2levels at a time when rCBF was significantly impaired in response to severe asphyxial insult. No such increase was noted in the periventricular white matter zones.
Laser-sealed arteriotomy: a reliable aneurysm model
Authors: Quigley Matthew R. , Heiferman Kenneth , Kwaan Hau C. , Vidovich Danko , Nora Peter , Cerullo Leonard J.
Published: May 2009

✓ Laser-assisted vascular anastomosis (LAVA) is associated with a significant aneurysm problem when it is applied to small arteries. The etiology of this phenomenon was investigated by creating arteriotomies of different lengths and orientation in the rat carotid artery and sealing them with the milliwatt CO2 laser. It was found that increasing the arteriotomy length from 0.5 to 1.0 mm significantly raised aneurysm occurrence (4/17 vs. 25/28, chi-square: p < 0.001) regardless of orientation. Systemic hypertension (systolic blood pressure ≥ 170 mm Hg) also significantly affected the aneurysm rate among the 0.5-mm arteriotomy group, raising aneurysm occurrence from 23.5% (4/17) to 100% (14/14) (p < 0.001). Assuming that the stay-sutures used for LAVA's act as rigid supports, the rate of aneurysm occurrence must be related to the distance between sutures. This phenomenon has been exploited to create a reliable aneurysm model.
Reliability of left and right indicators in CT scanning of the head
Authors: Luessenhop Alfred J. , Schellinger Dieter
Published: May 2009

✓ A case is described in which incorrect preliminary programming of a computerized tomography (CT) machine caused transposition of the left- and right-side indicators in a CT scan, which led to craniotomy on the normal side. The possible mechanism for this is incorrect pre-scan programming of the CT scanner with respect to patient positioning in the scanner gantry. This error, although unlikely, is still possible with the present generation of CT scanners.
Cervico-occipital teratoma in the newborn infant
Authors: Naor Norah , Merlob Paul , Heilbronn Yechiel , Ziv Nitsa , Reisner Salomon H.
Published: May 2009

✓ A case of cervico-occipital teratoma in a neonate is presented. This is the third reported case of teratoma in this unusual location and the first excised during the neonatal period. The radiographic and histological examination, treatment, and follow-up findings in this case are presented, along with a review of the literature.
The predictive value of cerebral anaerobic metabolism with cerebral infarction after head injury
Authors: Robertson Claudia S. , Grossman Robert G. , Goodman J. Clay , Narayan Raj K.
Published: May 2009

✓ Cerebral ischemia is a common mechanism of secondary brain injury following severe head injury. The cerebral metabolic rate of oxygen (CMRO2) and of lactate (CMRL), as well as cerebral blood flow (CBF) were measured daily for 5 days after head injury in 44 comatose head-injured patients to determine if metabolic changes could identify the patients who would develop cerebral infarction. Of 41 patients whose CBF remained at levels regarded as adequate to prevent infarction (CBF ≥ 0.2 ml/gm/min), the six who showed a cerebral infarction on computerized tomography (CT) scans exhibited characteristic cerebral metabolic patterns: a CMRO2of less than 0.6µmol/gm/min on one or more of the days monitored, and markedly elevated cerebral lactate production (CMRL < −0.06µmol/gm/min) on Days 1 and/or 2 after injury. Patients who had no areas of infarction on serial CT scans typically had a CMRO2of 0.6µmol/gm/min or higher and a low cerebral lactate production. Measurement of CMRO2and CMRL can be obtained at the bedside and can indicate the presence of an evolving ischemic infarct after head injury.
The effect of nimodipine on intracranial pressure
Authors: Hadley Mark N. , Spetzler Robert F. , Fifield Mary S. , Bichard William D. , Hodak John A.
Published: May 2009

✓ Nimodipine was administered by intravenous infusion to six male baboons before, during, and after 6 hours of middle cerebral artery occlusion. Intracranial pressure (ICP) and systemic blood pressure were monitored continuously. An epidural balloon was inflated at regular intervals at three levels of arterial CO2 tension (25, 35, and 50 mm Hg) before and after the administration of nimodipine, and volume-pressure curves were generated. In every case, curves generated after intravenous nimodipine infusion were lower and shifted more to the right than the same set of curves generated before nimodipine administration, regardless of the baseline ICP. The reduction in ICP following nimodipine infusion was not due to a reduction in mean arterial blood pressure and was statistically significant at all three levels of pCO2 (p < 0.01). These results suggest that, in the presence of elevated ICP due to cerebral infarction, there is no increased risk of exacerbating intracranial hypertension with the addition of nimodipine.
Oculomotor nerve regeneration in rats
Authors: Fernandez Eduardo , Gangitano Carlo , Del Fà Aurora , Sangiacomo Corrado Olivieri , Talamonti Giuseppe , Draicchio Francesco , Sbriccoli Alessandro
Published: May 2009

✓ To study oculomotor nerve regeneration in rats, the oculomotor nerve was approached microsurgically and was sectioned at the base of the skull. The nerve stumps were reapproximated and affixed with a plasma clot in Group I animals and were separated by a gap in Group II animals. Visceral eye motility was evaluated weekly between 1 day and 40 weeks after surgery by recording the pupillary diameter under standardized photic stimulation. Somatic eye motility was assessed after 26 weeks by measuring the ocular displacement evoked by vestibular stimulation in the horizontal and vertical planes. Nerve regeneration was documented histologically and morphometrically at 8, 16, and 40 weeks after section. The selectivity of axonal regeneration to the extraocular muscles was investigated after 26 weeks by mapping (with injection of retrograde horseradish peroxidase) the motoneurons that supplied each reinnervated muscle.

Between 6 and 20 weeks after section, the pupil diameter showed a progressive reduction in Group I rats, and no changes were observed in Group II rats. Compared with normal rats, the amplitude of horizontal and vertical ocular displacements was decreased, respectively, by 30% and 45% in Group I and by 65% and 80% in Group II. In Group I rats, the vestibular stimulation in the horizontal plane evoked anomalous eye movements with vertical components. On histological examination, regenerated nerves showed a progressive increase of axonal diameter and myelin-sheath thickness. Reinnervated muscles were associated with a less specific, bilateral representation in the midbrain compared with normal muscles, which have unilateral representation. The changes of the somatotopic organization were interpreted as being the result of the misdirected regrowth of axons in the postlesional nerve stump and of the collateral sprouting in the midbrain.
Bacterial adhesion to cerebrospinal fluid shunts
Authors: Guevara Juan A. , Zúccaro Graciela , Trevisán Alejandro , Denoya Claudio D.
Published: May 2009

✓ Bacterial adherence to cerebrospinal fluid (CSF) shunts was analyzedin vivoandin vitro. Scanning electron micrographs (SEM's) of catheters removed from pediatric patients with shunts infected byStaphylococcus aureusorKlebsiella pneumoniaerevealed numerous bacterial cells and microcolonies, leukocytes, and erythrocytes attached to the CSF catheters' inner walls, as well as the existence of surface irregularities, such as fissures, rugosities, and holes. Permeability analyses and SEM's demonstrated that catheters develop physical alterations over the period of implantation. Different bacterial strains presented a differentin vitroadherence to CSF shunts, suggesting that this attachment may be affected by specific properties of the outer structures of each strain.

The attachment of microbial pathogens to CSF shunts seems to contribute to the persistence of bacterial cells within a catheter and the onset of recurrent shunt infection. This study demonstrated that some bacteria can remain attached within shuntsin vitrodespite a CSF flow at rates up to 200 times higher than those normally demonstratedin vivo. Furthermore, surface irregularities found throughout this study may help to anchor and hide bacterial microcolonies. Based on these findings, it seems advisable to remove an infected shunt and to replace it with a new one after proper antimicrobial therapy, in order to prevent recurrent infections.
Audible cerebrospinal fluid flow through a ventriculoperitoneal shunt
Authors: Ordia Joe I. , Mortara Ronald W. , Spatz Edward L.
Published: May 2009

✓ An audible, noisy cerebrospinal fluid flow is an uncommon sequela of ventriculoperitoneal shunting. Two cases presenting this phenomenon are described.
Specific induction of ACNU-resistance in V79 Chinese hamster cells and C6 rat glioma cells
Authors: Horie Yukio , Arai Kenji , Endoh Shunro , Kuroki Toshio , Takaku Akira
Published: May 2009

✓ The antitumor compound ACNU (1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride) is widely used for treatment of malignant brain tumors. The authors have investigated the mechanism of acquisition of ACNU resistance at the cellular level by isolating ACNU-resistant mutants from V79 Chinese hamster cells and C6 rat glioma cells after treatment of the cells with ACNU or other alkylating agents. In V79 Chinese hamster cells, ACNU at 1 to 4 µg/ml caused dose-dependent induction of drug-resistant mutants to ACNU (10 µg/ml) and 8-azaguanine (20 µg/ml), but not to ouabain (1 mM). Values for the mean lethal dose of ACNU-resistant mutants were 2.4 to 17.2 times those of the parent V79 cells. The ACNU-resistant phenotype was stable during an observation period of 13 weeks. The ACNU seemed to have a specific effect in inducing ACNU-resistant mutations, because no ACNU-resistant mutations were induced by treatment of the cells with other known mutagens, such as N-methyl-N′-nitro-N-nitrosoguanidine, methylmethanesulfonate, and ethylmethanesulfonate. The C6 rat glioma cells also showed a significant mutagenic response to ACNU, producing ACNU- and 5-fluorouracil-resistant mutants. The present results have the important therapeutic and mechanistic implication that ACNU is a potent mutagen and induces mutants that are resistant to ACNU and to other drugs.
The effect of craniectomy on the biomechanics of normal brain
Authors: Hatashita Shizuo , Hoff Julian T.
Published: May 2009

✓ Does an open skull alter the fundamental biomechanical properties of normal brain tissue? This question was studied in 32 anesthetized cats, 16 of which underwent a standard craniectomy (2.5 × 2.0 cm) in the left frontoparietal region. Brain tissue pressure, regional cerebral blood flow (rCBF), and brain water content were measured from the same area of cortical gray and white matter, and intracranial pressure (ICP) was recorded from the cisterna magna. Brain tissue resistance, tissue compliance, and the pressure-volume index were analyzed in response to a bolus injection of saline into brain tissue or the cisterna magna. Cerebrovascular resistance was also calculated.

In craniectomized animals 2 hours after surgery, ICP had fallen to 3.75 ± 0.39 mm Hg, and cortical gray and white matter tissue pressure had fallen to 3.19 ± 0.47 and 4.69 ± 0.54 mm Hg, respectively (mean ± standard error of the mean); these variables did not fall further over 4 hours. The pressure-volume index in the same animals increased significantly from 0.67 ± 0.01 to 0.86 ± 0.04 ml. Tissue compliance rose in the cortical gray matter but tissue resistance fell, approximating that found in subjacent white matter. There was no significant difference between animals with and without craniectomy in rCBF, cerebrovascular resistance, or brain water content in either gray or white matter.

These findings indicate that in the cat craniectomy causes an increase in the compensatory capacity of the intracranial cavity to increased volume. The data also indicate that cortical tissue has high hydraulic conductivity and compliance when the skull is opened.
Nonsuture microvascular anastomosis using an Nd-YAG laser and a water-soluble polyvinyl alcohol splint
Authors: Niijima Kyo Huang , Yonekawa Yasuhiro , Handa Hajime , Taki Waro
Published: May 2009

✓ Anastomosis of rat common carotid artery was performed without sutures, using a neodymium (Nd)-YAG laser at 20 W for 100 msec; this power and exposure had been found optimal in preliminary experiments. An intraluminal intervascular splint made of water-soluble polyvinyl alcohol, which dissolved and disappeared within a few minutes after recirculation of blood, was used for precise “intima-to-intima” coaptation. No stay sutures or glue were required during the procedure.

There was a 92% patency rate 24 hours after surgery, and the anastomosed vessels were still patent on the 7th and 30th postoperative days. Complications such as aneurysm formation or stenotic change were negligible. The fusion of the muscle layer and collagen fibers of the media in the anastomosis was confirmed histologically. A tensile strength test immediately following operation and 1 week later showed that this anastomosis was significantly better than that achieved with the usual manual suture method. The major advantages of this technique, combined with use of a water-soluble polyvinyl alcohol splint, are rapidity, consistency of results, and firm fusion with no residual foreign body.
Magnetic resonance imaging and computerized tomography scanning of herpes simplex encephalitis
Authors: Neils Eric W. , Lukin Robert , Tomsick Thomas A. , Tew John M.
Published: May 2009

✓ The authors present two cases of herpes simplex encephalitis (HSE) in which computerized tomography (CT) scanning and magnetic resonance imaging (MRI) were performed. They also review the literature on the use of these imaging modalities in cases of HSE. The striking changes noted in these cases on T2-weighted magnetic resonance images in comparison to the CT findings suggest that MRI will help speed recognition of nonhemorrhagic HSE abnormalities.
Congenital fourth ventricular midline outlet obstruction
Authors: Rifkinson-Mann Stephanie , Sachdev Ved P. , Huang Yung Peng
Published: May 2009

✓ Obstruction of the foramen of Magendie unrelated to illness or trauma is rare in adults. Two cases of congenital membranous occlusion of the foramen of Magendie in adults are presented. Analysis of the reported cases of fourth ventricular outlet obstruction disclosed only three similar cases.
Tethered cervical spinal cord
Authors: Eller Theodore W. , Bernstein Lawrence P. , Rosenberg Richard S. , McLone David G.
Published: May 2009

✓ A case of congenital tethered cervical spinal cord is presented in a young adult. Metrizamide computerized tomography was the most useful imaging technique for identifying the tethered spinal cord. Intraoperative somatosensory evoked potentials correlated well with clinical improvement following surgery.
Reevaluation of an experimental streptococcal canine brain abscess model
Authors: Kurzydlowski Henry , Wollenschlager Cynthia , Venezio Frank R. , Ghobrial Mona , Soriano Morris Marc , Reichman O. Howard
Published: May 2009

✓ An experimental cerebral abscess model in which alpha-hemolytic Streptococci were inoculated into the brain parenchyma of dogs was evaluated for assessment of antimicrobial therapy. Intracerebral ring-enhancing lesions were visualized by computerized tomography, but they resolved after time without therapeutic intervention. Histopathological study demonstrated evolution of the lesions into sterile granulomas. Quantitative cultures were performed and uniformly became sterile in the early cerebritis stage, approximately 3 days after bacterial inoculation. Therefore, this brain abscess model should not be utilized for the evaluation of new antimicrobial treatment regimens. Rather, other models which document persistent viable organisms within cerebral abscesses need to be developed.
Protection against spinal cord ischemia with insulin-induced hypoglycemia
Authors: Robertson Claudia S. , Grossman Robert G.
Published: May 2009

✓ The effect of insulin-induced reduction in blood glucose to 65 ± 20 mg/dl (mean ± standard deviation) on recovery of electrophysiological function and extracellular lactate concentration was studied in a rabbit model of spinal cord ischemia. These results were compared to findings in animals with spinal cord ischemia that either were fasted overnight (fasted group: blood glucose 97 ± 26 mg/dl) or had no pretreatment (control group: blood glucose 172 ± 65 mg/dl). The aorta was occluded until the postsynaptic waves of the spinal somatosensory evoked potentials (SSEP's) had been absent for 20 minutes, a period of ischemia that produces paraplegia in 100% of untreated rabbits. The total aortic occlusion time was not significantly different in the three groups. Recovery of the SSEP's was significantly better in the insulin-treated animals than in the fasted or control animals. The N3 wave of the SSEP's, which has been found to correlate best with neurological recovery, returned to 65% ± 48% of the preischemia amplitude in the insulin-treated animals, compared to 40% ± 34% in the fasted group and 26% ± 24% in the control animals. Extracellular lactate concentration in the spinal cord increased immediately after occlusion of the aorta, reached a plateau as the postsynaptic waves disappeared from the SSEP's, and then increased a second time during the first 15 minutes of reperfusion. The peak lactate concentration during ischemia and during reperfusion correlated with the preischemia glucose concentration (r = 0.60336 and r = 0.76930, respectively). Lactate concentration in the spinal cord was higher during ischemia and throughout the first 2 hours of reperfusion in the control and fasted animals than in the insulin-treated animals. During the 2nd hour of reperfusion, lactate concentration was significantly higher in the control animals than in the fasted animals. Reduction in blood glucose with insulin improves recovery of electrophysiological function after spinal cord ischemia, probably because of reduced lactic acid production, especially during the early reperfusion period.
Neurosurgical management of carotid sinus hypersensitivity
Authors: Simpson Richard K. , Pool James L. , Grossman Robert G. , Rose James E. , Taylor Addison A.
Published: May 2009

✓ Carotid sinus hypersensitivity (CSH) can cause severe bradycardia, hypotension, asystole, and cardiac arrest. Three patients with the combined (mixed) cardioinhibitory and vasodepressor form of CSH were studied with intensive cardiovascular monitoring. After medical management failed, the patients were successfully treated by transection of the glossopharyngeal nerve and upper rootlets of the vagus nerve at their exit from the brain stem. Methods of diagnosis of CSH, and the benefits and limitations of medical and surgical therapies are discussed.
Unusual intercarotid anastomosis associated with anterior communicating artery aneurysm
Authors: Tracy Patrick T.
Published: May 2009

✓ The case is presented of a 34-year-old man with subarachnoid hemorrhage from rupture of an anterior communicating artery aneurysm. The magnetic resonance imaging and angiographic findings are reported. Angiography showed the aneurysm plus an unusual anastomosis between the intracavernous portions of both internal carotid arteries. The anastomosis crossed posterior to the base of the dorsum sellae and was associated with absence of the right internal carotid artery and the A1 segment of the right anterior cerebral artery. This is the 11th case of such an unusual intercarotid anastomosis reported in the literature.
Postoperative magnetic resonance imaging artifacts
Authors: Firsching Raimund P. , Heindel Walter , Ernestus Ralf-Ingo , Frowein Reinhold A. , Bunke Jürgen
Published: May 2009

✓ Artifacts are occasionally encountered on magnetic resonance imaging after operation. These may be due to minute metallic particles from neurosurgical instruments. Particles not detectable on plain x-ray films or computerized tomography scans may cause local change of magnetic resonance activity, resulting in a deceptive magnetic resonance appearance. Three illustrative case reports are presented.
Interstitial laser photochemotherapy of rhodamine-123-sensitized rat glioma
Authors: Powers Stephen K. , Beckman William C. , Brown J. Tony , Kolpack Linda C.
Published: May 2009

✓ The effect of interstitial laser photochemotherapy with the mitochondrial-specific intravital dye rhodamine-123 (Rh-123) was studied using a malignant rat glioma model system (RT2). Tumors were transplanted subcutaneously into the flank of athymic mice and into the cerebrum of adult rats. The Rh-123 photosensitization was produced by direct intratumoral injection of Rh-123 into the mouse RT2 flank tumors and by intravenous Rh-123 administration to adult rats with implanted RT2 intracerebral tumors. Intratumoral irradiation with 150 mW of argon laser light for an exposure time of 15 minutes was performed using a conical sapphire-tipped quartz optical fiber. Control groups of animals received either no treatment, Rh-123 injections, or administration of 150 mW of argon laser light for 15 minutes. Both flank and intracerebral tumors showed progressive diminution in size after treatment with Rh-123 photochemotherapy. There was no evidence of tumor recurrence in 60% of Rh-123 photochemotherapy-treated tumors. Recurrences in tumors treated with Rh-123 photochemotherapy usually appeared at the periphery of the original tumor at 10 days after treatment. Histologically, photochemotherapy-treated intracerebral tumors showed progressive shrinkage with increasing tumor necrosis over time. The finding of residual or recurrent tumor at the periphery of the original tumor mass suggests that the lack of penetration of the blue-green (argon) light was responsible for preventing complete tumor ablation. Our results suggest that Rh-123 photochemotherapy can destroy malignant gliomasin vivo; however, the poor penetrability of the photoactivating blue-green light may limit the effectiveness of this treatment for large or extensively invasive tumors.
The effect of 125I interstitial radiotherapy on blood-brain barrier function in normal canine brain
Authors: Groothuis Dennis R. , Wright Donald C. , Ostertag Christoph B.
Published: May 2009

✓ Blood-brain barrier (BBB) function was studied in 14 normal dogs at time periods from 7 to 717 days after permanent insertion of 5- to 7-mCi seeds of iodine-125 (125I) for interstitial radiation. The BBB function was measured with carbon-14-labeled alpha aminoisobutyric acid (AIB) and quantitative autoradiography, and expressed as a unidirectional blood-to-brain transfer constant, K. The 125I radiation lesions consisted of three concentric histologically and functionally distinct zones: 1) a central zone of calcified necrosis; 2) a spongy fluid-filled zone; and 3) a narrow rim (2.6 ± 0.6 mm wide) of viable brain tissue with increased permeability. Within this rim, the mean value of the K of AIB was 5.8 times that of normal cortex. Over the 7- to 392-day time period the value of K remained rather constant, and by 716 days K values had returned to normal. There was moderate regional variation in the value of K; it was highest in the white matter and lowest in the gray matter surrounding the radiation lesion. The radiation lesion progressively increased in size from 7 to 80 days, after which there was little change. This study illustrates that the geographically circumscribed radiation from 125I seeds is accompanied by similarly well-defined changes in BBB function, which may persist for over 1 year following insertion of the 125I seed. This altered BBB function is probably responsible for the cerebral edema associated with 125I interstitial radiotherapy.
Experimental induction of cerebral aneurysms in monkeys
Authors: Hashimoto Nobuo , Kim Choegon , Kikuchi Haruhiko , Kojima Masayuki , Kang Yoo , Hazama Fumitada
Published: May 2009

✓ Saccular cerebral aneurysms were successfully induced in two monkeys treated with ligation of the common carotid artery, experimental hypertension, and β-aminopropionitrile feeding. The cerebral aneurysms developed on the large arteries at the base of the brain, such as the anterior communicating artery and the internal carotid artery at the origin of the posterior communicating artery. Because of the similarity of the monkey to man as a species, the present results strongly suggest the significance of postnatal aggravating factors in the development of cerebral aneurysms in man.
Sparganosis of the brain
Authors: Chan Sze-Tong , Tse C. H. , Chan Y. S. , Fong Dawson
Published: May 2009

✓ Cerebral sparganosis is a rare disease; to date only eight cases have been described. Two new cases of cerebral sparganosis occurring in Chinese patients living in a metropolitan area are reported. Their clinical presentation and investigative results are presented and the operative and histological findings detailed. A brief review of the condition is given and the possible source of infection discussed.
Acute epidural hematoma: an analysis of factors influencing the outcome of patients undergoing surgery in coma
Authors: Lobato Ramiro D. , Rivas Juan J. , Cordobes Francisco , Alted Emilio , Perez Carlos , Sarabia Rosario , Cabrera Antonio , Diez Isidoro , Gomez Pedro , Lamas Eduardo
Published: May 2009

✓ Mortality due to epidural hematoma is virtually restricted to patients who undergo surgery for that condition while in coma. The authors have analyzed the factors influencing the outcome of 64 patients who underwent epidural hematoma evacuation while in coma. These patients represented 41% of the 156 patients operated on for epidural hematoma at their centers after the introduction of computerized tomography (CT). Eighteen patients (28.1%) died, two (3.1%) became severely disabled, and 44 (68.8%) made a functional recovery. The mortality rate for the entire series was 12%, significantly lower than the 30% rate observed when only angiographic studies were available.

A significant correlation was found between the final result and the mechanism of injury, the interval between trauma and surgery, the motor score at operation, the hematoma CT density (homogeneous vs. heterogeneous), and the hematoma volume. The patient's age, the course of consciousness before operation (whether there was a lucid interval), and the clot location did not correlate with the final outcome.

The mortality rate was significantly higher in patients operated on within 6 hours or between 6 and 12 hours after injury than in those undergoing surgery 12 to 48 hours after injury. Compared with the patients operated on later, the patients undergoing surgery in the early period were, on the average, older and had more rapidly developing symptoms, more pupillary changes, lower motor scores at surgery, larger hematomas, a higher incidence of mixed CT density clots, more severe associated intracranial lesions, and higher postoperative intracranial pressure (ICP).

The mechanism of trauma seems to influence the course of consciousness before and after surgery. Passengers injured in traffic accidents had a lower incidence of a lucid interval and longer postoperative coma than patients with low-speed trauma, suggesting more frequent association of diffuse white matter-shearing injury. The duration of postoperative coma correlated with the morbidity rate in survivors.

Forty-eight patients (75%) had one or more associated intracranial lesions, and 70% of these required treatment for elevation of ICP after hematoma evacuation. An ICP of over 35 mm Hg strongly correlated with poor outcome; administration of high-dose barbiturates was the only effective means for lowering ICP in nine of 15 patients who developed severe intracranial hypertension after surgery. This study attempts to identify patients at greater risk for presenting postoperative complications and to define a strategy for control CT scanning and ICP monitoring.
Subdural tension pneumocephalus following surgery for chronic subdural hematoma
Authors: Ishiwata Yusuke , Fujitsu Kazuhiko , Sekino Tsunemi , Fujino Hideyo , Kubokura Takamichi , Tsubone Kyoji , Kuwabara Takeo
Published: May 2009

✓ The computerized tomography (CT) findings were analyzed in five cases of subdural tension pneumocephalus following surgery for chronic subdural hematoma. They were compared with CT scans in 14 cases of asymptomatic subdural pneumocephalus. In this study, two new CT findings were identified that suggest increased tension of the subdural air. Subdural air separates and compresses the frontal lobes, creating a widened interhemispheric space between the tips of the frontal lobes that mimics the silhouette of Mt. Fuji. The presence of air between the frontal tips associated with massive air inclusion over the frontal lobes presumably indicates increased tension of the subdural air. The “Mt. Fuji sign” was seen in four of the five cases with subdural tension pneumocephalus. The other finding was the presence of multiple small air bubbles scattered through several cisterns (”air bubble sign”). It is postulated that these air bubbles enter the subarachnoid space through a tear in the arachnoid membrane caused by increased tension of air in the subdural space. This finding was seen in four cases with subdural tension pneumocephalus. These two CT findings are helpful in making a diagnosis of subdural tension pneumocephalus following surgery for chronic subdural hematoma.
Intolerance to enteral feeding in the brain-injured patient
Authors: Norton Jane A. , Ott Linda G. , McClain Craig , Adams Linas , Dempsey Robert J. , Haack Dennis , Tibbs Phillip A. , Young A. Byron
Published: May 2009

✓ Calorie and protein supplementation improves nutritional status. This support may improve outcome and decrease morbidity and mortality in acutely brain-injured patients. Investigators have observed a poor tolerance to enteral feedings after brain injury and have noted that this persists for approximately 14 days postinjury. This delay has been attributed to increased gastric residuals, prolonged paralytic ileus, abdominal distention, aspiration pneumonitis, and diarrhea.

In the present investigation, 23 brain-injured patients with an admission 24-hour peak Glasgow Coma Scale (GCS) score between 4 and 10 were studied for 18 days from hospital admission. The mean duration from injury to initiation of full-strength, full-rate enteral feeding was 11.5 days. Seven of the 23 patients tolerated enteral feedings within the first 7 days following hospital admission (mean 4.3 days), four patients tolerated feedings between 7 and 10 days postadmission (mean 9 days), and 12 patients did not tolerate feedings until after 10 days postinjury (mean 15.9 days). There was a marginally significant relationship between low GCS scores on admission and length of days to enteral feeding tolerance (p = 0.07). A significant inverse relationship was observed between daily peak intracranial pressure (ICP) and time to tolerance of feedings (p = 0.02). There was no significant relationship between feeding tolerance and days to return of bowel sounds (p = 0.12). Serum albumin levels decreased during the investigation (mean ± standard error to the mean: 3.2 ± 0.12 gm/dl on Day 1; 2.7 ± 0.23 gm/dl on Day 16; normal = 3.5 to 5.0 gm/dl), whereas the percentage of patients tolerating feedings increased over the course of the study. The authors conclude that patients with acute severe brain injury do not adequately tolerate feedings via the enteral route in the early postinjury period. Tolerance of enteral feeding is inversely related to increased ICP and severity of brain injury. It is suggested that parenteral nutritional support is required following brain injury until enteral nutrition can be tolerated.
Retrograde degeneration of corticospinal axons following transection of the spinal cord in rats
Authors: Pallini Roberto , Fernandez Eduardo , Sbriccoli Alessandro
Published: May 2009

✓ The extent of the retrograde degeneration of corticospinal axons following transection of the spinal cord was studied in rats by labeling corticospinal axons with anterogradely transported horseradish peroxidase injected in the sensorimotor cortex. Axotomized corticospinal axons underwent progressive and continuing retrograde degeneration. In specimens examined 5, 14, 28, and 56 days after trauma, the tips of the transected corticospinal axons were seen to terminate at 181 ± 80 µm, 977 ± 203 µm, 1751 ± 344 µm, and 2559 ± 466 µm (mean ± standard deviation), respectively, from the site of transection. The rate of retrograde degeneration varied according to the interval after spinal cord transection, as follows: 36.2 µm/day during the first 5 days; 88.4 µm/day between 5 and 14 days; 55.3 µm/day between 14 and 28 days; and 28.8 µm/day between 28 and 56 days. These findings may serve as useful parameters for the objective assessment of therapeutic modalities in spinal cord injury research.
The effects of hypovolemic hypotension on high-energy phosphate metabolism of traumatized brain in rats
Authors: Ishige Naoki , Pitts Lawrence H. , Berry Isabelle , Nishimura Merry C. , James Thomas L.
Published: May 2009

✓ To clarify the effect of hypovolemic hypotension on high-energy phosphate metabolism in head injury, sequential changes inin vivophosphorus-31 magnetic resonance (31P MR) spectra were compared in 35 rats after impact injury with and without hypotension. Fourteen rats were subjected to hypotension alone (mean arterial blood pressure (MABP) of either 40 or 30 mm Hg for 60 minutes), seven to fluid-percussion impact injury (4 to 5 atm) alone, and 14 to impact injury and hypotension (MABP of 40 to 30 mm Hg). Impact injury alone caused a transient decrease in the phosphocreatine (PCr) level and an increase in the inorganic phosphate (Pi) value. While hypotension alone produced only small changes on31P MR spectra, impact injury plus hypotension caused pronounced changes. Impact injury and an MABP of 40 mm Hg caused a 50% decrease in PCr concentration and an approximately twofold increase in Pi level, which were significantly greater than values in rats with impact injury alone. Impact injury and an MABP of 30 mm Hg also caused a significant decrease in adenosine triphosphate value, which was not observed in rats with impact injury alone or with an MABP of 30 mm Hg alone. Decreases in intracellular pH were greater in rats with impact injury and hypotension. After traumatic injury, the brain is extremely vulnerable to hypovolemic hypotension, as reflected in the loss of high-energy phosphates in brain.
Rapid resolution of acute epidural hematoma
Authors: Aoki Nobuhiko
Published: May 2009

✓ Two cases of acute epidural hematoma with rapid resolution followed by a benign clinical course are reported. Because of the concomitant increase in the epicranial hematoma over a linear skull fracture in each case, the acute epidural hematoma was presumed to have been decompressed into the epicranial region through the fracture line.
Biphasic ventricular dilatation following posterior fossa subdural hematoma in the full-term neonate
Authors: Tanaka Yuichiro , Sakamoto Keizo , Kobayashi Shigeaki , Kobayashi Norio , Muraoka Shinsuke
Published: May 2009

✓ Five full-term neonates with a posterior fossa subdural hematoma caused by birth injury are reported. All of the patients were successfully treated with surgery. They all presented with biphasic ventricular dilatation as demonstrated by serial computerized tomography (CT) scanning. The initial dilatation due to obstructive hydrocephalus disappeared after removal of the hematoma; however, a second dilatation without obstruction of the ventricular system developed between 2 and 4 weeks after surgery. A ventriculoperitoneal shunt was required in one case because of progressive enlargement of the head size in the chronic stage. The other four patients showed transient dilatation of the ventricles without symptoms of increased intracranial pressure. Subarachnoid hemorrhage associated with posterior fossa subdural hematoma is considered to be the most likely causative factor for the delayed ventricular dilatation. The degree of dilatation roughly depended on the volume of the subarachnoid clot that was demonstrated on the initial CT scan.
Partial characterization of a soluble mitogenic factor from medulloblastoma
Authors: Rutka James T. , Hall Jackson , Giblin Jane R. , Dougherty Dolores V. , Edwards Michael S. B. , Stern Robert , Rosenblum Mark L.
Published: May 2009

✓ To determine how medulloblastoma cells might influence the proliferation and phenotype of normal stromal cells, normal human leptomeningeal cells were treated in culture with medulloblastoma-conditioned medium; their ability to incorporate tritiated thymidine and synthesize collagen was measured. The treated leptomeningeal cells had a significantly greater uptake of tritiated thymidine and grew faster than control leptomeningeal cells. Immunofluorescence studies demonstrated a greater intensity of staining for procollagen type III in the cell layer of the treated cultures than in control cultures; diethylaminoethyl (DEAE)-cellulose chromatography of the medium showed that the treated cells synthesized predominantly type III collagen, whereas control cells synthesized type I collagen. Analysis of the medulloblastoma-conditioned medium revealed that the soluble factor responsible for these effects is an acid- and heat-stable protein. The increased proliferation and altered collagen synthesis induced in leptomeningeal cell cultures by a soluble factor from a medulloblastoma are examples of how tumor and stromal elements interact, and may be related to the process of desmoplasia often observed in medulloblastomas in vivo.
Fibrinolytic activity in experimental intracerebral hematoma
Authors: Masuda Toshikazu , Dohrmann George J. , Kwaan Hau C. , Erickson Robert K. , Wollman Robert L.
Published: May 2009

✓ In an attempt to investigate the role of tissue fibrinolytic activity in the resolution of intracerebral hematoma, an experimental model of intracerebral hematoma was developed in the rat. The fibrinolytic activity was studied using a histochemical fibrin slide technique. A total of 59 adult male rats were studied. Twenty-nine rats were used for developing the intracerebral hematoma model via injection of autologous whole blood into the left frontal lobe; in the remaining 30 rats, the intracerebral hematomas were studied sequentially. Intracerebral hematoma formation was unsuccessful in six (21%) of 29 rats. Four rats died in the immediate postoperative period and two showed no intraparenchymal clot. Intense fibrinolytic activity was demonstrated in the blood vessel walls of the normal brain, especially in the meninges, choroid plexus, and ependymal cell layer. In the initial stages of hematoma resolution, fibrinolytic activity was not seen in the hematoma or parenchyma except in the preexisting blood vessels. However, 3 to 5 days later, fibrinolytic activity was observed in the capillary buds surrounding the hematoma and among the infiltrating mononuclear cells. This activity increased for 7 to 10 days following formation of the hematoma and decreased after 21 to 28 days. It is concluded that tissue fibrinolytic activity associated with newly formed blood vessels appears to be important in lysis of intracerebral hematomas.
Peripheral nerve stimulation suppression of C-fiber-evoked flexion reflex in rats
Authors: Sjölund Bengt H.
Published: May 2009

✓ Transcutaneous electrical nerve stimulation (TENS) is an acknowledged clinical technique to alleviate chronic pain. Its effectiveness is still limited, however, and the stimulation parameters used are based on subjective reports from patients. In the present study, the systematic investigation of conditioning stimulation that was previously reported by the author has been extended to include short trains of stimuli at a low repetition rate (0.1 to 5 Hz) delivered to dissected skin and muscle nerves in the lightly anesthetized rat. The size of a C-fiber-evoked flexion reflex was utilized as a measure of transmission from nociceptive afferentnerve fibers in the spinal cord and was tested repeatedly after 30 minutes of conditioning TENS-like stimulation to adjacent nerves. At these low rates, stimulation of a muscle nerve was usually more effective in suppressing transmission from C-fibers to second-order neurons than was stimulation of a skin nerve. Furthermore, a stimulation strength recruiting both Group I–II and III muscle afferent fibers was more effective in depressing the C-fiber-evoked activity at all frequencies studied than was that activating Group I–II fibers only. A pulsetrain repetition rate of around 1 Hz was most effective. These findings should be taken into account when carrying out clinical TENS treatment.
Intrachiasmatic craniopharyngioma: a rare cause of chiasmal thickening
Authors: Brodsky Michael C. , Hoyt William F. , Barnwell Stanley L. , Wilson Charles B.
Published: May 2009

✓ The authors describe the case of a young man who presented with a central scotoma in one eye and a temporal hemianopsia in the other. Magnetic resonance imaging showed distinctive bilobed thickening of the chiasm and a “potbelly” expansion of the contiguous optic nerves. The distal portions of the intracranial optic nerves appeared normal. At craniotomy, incision of the lamina terminalis exposed intraventricular craniopharyngioma with anterior extension into the chiasm and proximal optic nerves. Partial resection of the tumor restored normal vision.
Primary leiomyosarcoma of the dura mater
Authors: Asai Akio , Yamada Hisashi , Murata Sadayoshi , Matsuno Akira , Tsutsumi Kazuo , Takemura Tamiko , Matsutani Masao , Takakura Kintomo
Published: May 2009

✓ A rare case of leiomyosarcoma arising from the dura mater is presented. A definite histological diagnosis was based on the electron microscopic features. Extensive removal of the tumor and postoperative radiation therapy resulted in complete remission. The etiology and the origin of this tumor are discussed.
A modified extended middle cranial fossa approach for acoustic nerve tumors
Authors: Shiobara Ryuzo , Ohira Takayuki , Kanzaki Jin , Toya Shigeo
Published: May 2009

✓ During the past 10 years, 125 operations for acoustic nerve tumors were performed on 114 patients at the authors' institution using a modified extended middle cranial fossa approach. This approach is based on a combination of King and Morrison's translabyrinthine-transtentorial approach and on the extended approach through the middle cranial fossa described by Bochenek and Kukwa. There were two hospital deaths (operative mortality 1.6%). In 102 operations on the initial tumor, total removal was performed in 89 cases (87%), and in 71 (80%) of these the facial nerve was anatomically preserved. Intracranial end-to-end anastomosis was performed on five of the 18 sacrificed facial nerves; a facial-hypoglossal anastomosis was carried out in the remaining 13 patients and in five (7%) of the 71 patients whose anatomically preserved facial nerve functioned poorly. In seven (39%) of the 18 patients in whom an attempt to preserve hearing was made, postoperative hearing was saved. In 23 operations on 17 patients for recurrent tumors, most of which had previously been removed subtotally via the suboccipital approach, total removal was accomplished in 13 (57% of the 23 reoperations and 76% of the 17 patients). At reoperation, the facial nerve was preserved in six (55%) of the 11 patients in whom the facial nerve had not been sacrificed. Postoperative leakage of cerebrospinal fluid occurred in 11 cases (8.8%), with rhinorrhea in 10 cases and otorrhea in one. Five of the fistulas were corrected by surgery and the rest healed spontaneously. Other complications were not significant.
Benign intraparenchymal brain cysts without an epithelial lining
Authors: Wilkins Robert H. , Burger Peter C.
Published: May 2009

✓ Three patients are presented who had benign intraparenchymal cysts of the brain. The wall of each cyst was biopsied and had no epithelial lining or other microscopic feature to indicate the etiology of the cyst. The authors review published information about benign brain cysts and speculate about the origin of those having a wall composed solely of neuroglial tissue.
Outcome from head injury related to patient' age
Authors: Luerssen Thomas G. , Klauber Melville R. , Marshall Lawrence F.
Published: May 2009

✓ A series of 8814 head-injured patients admitted to 41 hospitals in three separate metropolitan areas were prospectively studied. Of these, 1906 patients (21.6%) were 14 years of age or less. This “pediatric population” was compared to the remaining “adult population” for mechanism of injury, admission Glasgow Coma Scale score, motor score, blood pressure, pupillary reactivity, the presence of associated injuries, and the presence of subdural or epidural hematoma. The relationship of each of these factors was then correlated with posttraumatic mortality. Except for patients found to have subdural hematoma and those who were profoundly hypotensive, the pediatric patients exhibited a significantly lower mortality rate compared to the adults, thus confirming this generally held view. This study indicates that age itself, even within the pediatric age range, is a major independent factor affecting the mortality rate in head-injured patients.