bluuebunny/crossref_metadata_2025_split huggingface dataset:
Echocardiographic detection and treatment of intraoperative air embolism
Authors: Sato Shuzo , Toya Shigeo , Ohira Takayuki , Mine Tohru , Greig Nigel H. 
Published: May 2009

✓ A real-time two-dimensional echocardiogram was used to detect the presence of an air embolism in patients undergoing neurosurgical procedures in the sitting position. The technique could with good sensitivity detect the appearance of a single air bubble intraoperatively, thus allowing early intervention to prevent development of further air emboli. Two types of air embolism could be differentiated; the single-bubble type and the “stormy-bubble” type. The single-bubble type was observed during skin and muscle incisions, craniotomy, and brain lesion excision. Further embolism development was prevented by electrocoagulation and application of bone wax. The stormy-bubble type occurred during dura and muscle incisions and was prevented by electrocoagulation, reflection of the dura, or suturing the affected muscle.
The routine use of a Swan-Ganz catheter for removal of air embolism by suction proved effective for the treatment of the stormy-bubble type of air embolism. Masking the operative field with saline-soaked cotton strips was of moderate benefit in the stabilization of the single-bubble type of air influx, but proved to be of little value in controlling the entrance of the stormy-bubble type.
Ultrastructural morphology of the olfactory pathway for cerebrospinal fluid drainage in the rabbit
Authors: Erlich Stephanie S. , McComb J. Gordon , Hyman Shigeyo , Weiss Martin H. 
Published: May 2009

✓ Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination.
The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or singlelayered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.
Microvascular anatomy of the interpeduncular fossa
Authors: Pedroza Alfredo , Dujovny Manuel , Ausman James I. , Diaz Fernando G. , Artero Jose Cabezudo , Berman S. Kim , Mirchandani Haresh G. , Umansky Felix 
Published: May 2009

✓ An understanding of the microvascular anatomy of the midbrain and posterior diencephalon is essential in the surgical management of lesions in that region. A description of the arterial pattern of blood supply to these areas is the purpose of this study.
Perforating branches originating from the last 5 mm of the basilar artery, from the initial 7 mm of both superior cerebellar arteries (SCA's), and from the initial segment (P1 segment) of the posterior cerebral artery were studied in 56 unfixed human cadaver brain hemispheres. The brains were injected with polyester resin. The perforating branches penetrated through a small space in the upper part of the interpeduncular fossa. The anterior two-thirds of this space was occupied by the posterior perforated substance (PPS), and the posterior one-third was the site of penetration of the branches that supply the inferior mesencephalon. The PPS was divided into anterior and posterior halves. The anterior half was perforated by the paramedian thalamic arteries (diameter 0.57 ± 0.11 mm) while the superior paramedian mesencephalic arteries (diameter 0.20 ± 0.06 mm) perforated the posterior half. The perforating arteries originated from a trunk exclusive to the anterior half in 30%, from a trunk supplying both halves in 57%, and from a trunk exclusive to the posterior half in 13% of specimens. There were 26 naturally occurring anastomoses between the perforating branches. The paramedian inferior mesencephalic arteries penetrating the posterior one-third of the upper part of the interpeduncular fossa arose from the P1 segment in 32% of the brains studied, from the proximal 7 mm of the SCA in 45%, and from the last 5 mm of the basilar artery in 23%.
The right hemisphere: neuropsychological functions
Authors: Heilman Kenneth M. , Bowers Dawn , Valenstein Edward , Watson Robert T. 
Published: May 2009

✓ In the past two to three decades, clinicians and neuroscientists have been studying the functions of the right hemisphere. Neither hemisphere seems to be dominant in the absolute sense. Each appears to be specialized and is dominant for different functions. However, most functions require the cooperation of both hemispheres. When one is damaged, the other can often compensate for the damaged one. Lesions of the left hemisphere are associated with language (speech, reading, and writing) and praxic disorders, and lesions of the right hemisphere can result in visuospatial, attentional, and emotional disorders.
The authors review some of the major behavioral disorders associated with right hemisphere dysfunction and concentrate on three major types of disorders — visuospatial, attentional, and emotional. Although not all the behavioral defects associated with right hemisphere damage can be subgrouped under these three types, they are the ones most often associated with right hemisphere lesions.
Operative management of tumors involving the cavernous sinus
Authors: Sekhar Laligam N. , Møller Aage R. 
Published: May 2009

✓ In the past, neurosurgeons have been reluctant to operate on tumors involving the cavernous sinus because of the possibility of bleeding from the venous plexus or injury to the internal carotid artery (ICA) or the third, fourth, or sixth cranial nerves. The authors describe techniques for a more aggressive surgical approach to neoplasms in this area that are either benign or locally confined malignant lesions.
During the last 2 years, seven tumors involving the cavernous sinus have been resected: six totally and one subtotally. The preoperative evaluation included axial and coronal computerized tomography, cerebral angiography, and a balloon-occlusion test of the ICA. Intraoperative monitoring of the third, fourth, sixth, and seventh cranial nerves was used to assist in locating the nerves and in avoiding injury to them. The first major step in the operative procedure was to obtain proximal control of the ICA at the petrous apex and distal control in the supraclinoid segment. The cavernous sinus was then opened by a lateral, superior, or inferior approach for tumor resection. Temporary clipping and suture of the ICA was necessary in one patient.
None of the patients died or suffered a stroke postoperatively. Permanent trigeminal nerve injury occurred in three patients; in two, this was the result of tumor invasion. One patient suffered temporary paralysis of the third, fourth, and sixth cranial nerves, and in another the sixth cranial nerve was temporarily paralyzed. Preoperative cranial nerve deficits were improved postoperatively in three patients. Radiation therapy was administered postoperatively to four patients. These seven patients have been followed for 6 to 18 months to date and none has shown evidence of recurrence of the intracavernous tumor.
Effect of vasopressin on cold-induced brain edema in cats
Authors: Reeder Ralph F. , Nattie Eugene E. , North William G. 
Published: May 2009

✓ Centrally released arginine vasopressin (AVP) has been implicated in the regulation of intracranial pressure (ICP) and brain water, and is elevated in the cerebrospinal fluid (CSF) of some patients with pseudotumor cerebri or subarachnoid hemorrhage. The authors have examined the relationship of AVP levels in CSF to ICP and brain water content in three experimental groups of cats with and without cold-induced vasogenic edema. With the cats under general anesthesia, a cold lesion was made and cannulas were placed in the cisterna magna, lateral ventricle, and aorta. Subsequent central and systemic measurements were made while the animals were awake and free-roaming.
In Experiment 1, endogenous AVP levels in CSF were measured every 12 hours over a 48-hour period by radioimmunoassay in cats with sham craniotomy, mild edema, or moderate edema; no significant difference was found between groups although a diurnal variation was seen (range 2 to 18 pg/ml). In Experiment 2, either carrier solution or AVP, in doses of 1.5 or 30 ng, was administered via a lateral ventricle every 2 hours over 24 hours in unlesioned cats. In Experiment 3, cats received 2 or 35 ng of carrier solution or AVP in a similar manner, but coupled with a cold lesion. The CSF AVP levels ranged from an average of 100 to 681 pg/ml and 1.4 to 11.9 ng/ml in the two dose groups in both experiments. Neither the low nor the high dose had an effect on brain water content in normal white matter (Experiment 2), but both doses increased brain water content in edematous white matter (p < 0.05 in Experiment 3), as determined by wet and dry weight measurements of standardized pieces of white matter. The ICP was decreased by high-dose AVP in normal cats (p < 0.01 at 24 hours), but in lesioned cats was unchanged by low-dose and increased by high-dose AVP (p < 0.05 at 18 hours). The authors conclude that pharmacological doses of central AVP facilitate the production of vasogenic edema.
Observations on the perioperative management of aneurysmal subarachnoid hemorrhage
Authors: Finn S. Sam , Stephensen Sigurdur A. , Miller Carole A. , Drobnich Laura , Hunt William E. 
Published: May 2009

✓ Thirty-two patients with aneurysmal subarachnoid hemorrhage (SAH) were managed according to a protocol based on pain control and hemodynamic manipulation, monitored by an arterial line and Swan-Ganz catheter. Hemodynamic parameters were adjusted to four clinical situations. 1) For the unoperated patient with no neurological deficit, the regimen aims to maintain pulmonary wedge pressure (PWP) at 10 to 12 mm Hg, and the cardiac index (CI) and blood pressure (BP) at normal levels. 2) For the unoperated patient presenting with or developing neurological deficit, the PWP is increased until the deficit is reversed or the CI falls; the CI is high, and the BP normal. 3) For the postoperative patient with no neurological deficit, the PWP is maintained at 12 to 14 mm Hg, the CI is a high normal, and the BP is normal. 4) For the postoperative patient developing neurological deficit but showing no surgical complication on the computerized tomography scan, the PWP is increased until the deficit is reversed or the CI falls; the CI is high and the BP is increased with vasopressors if necessary.
Fourteen patients developed neurological deficits either preoperatively, postoperatively, or both. Neurological deficits were repeatedly reversed by increasing the PWP, as measured hourly. In several patients an optimal wedge pressure was determined, below which deficits would reappear. In one patient whose neurological deficit was reversed on several occasions by increasing the PWP, the optimal PWP rose after each episode until it reached 22 mm Hg.
Detailed event-related analysis of these patients' course illustrates these phenomena well. The optimal PWP varied from patient to patient, but ranged most frequently from 14 to 16 mm Hg. Meticulous monitoring of the patients' neurological status coupled with prompt correction of low PWP (assuming an adequate CI) has proven to be an effective way to prevent and reverse neurological deficits following aneurysmal SAH.
Meningiomas of the clivus and apical petrous bone
Authors: Mayberg Marc R. , Symon Lindsay 
Published: May 2009

✓ Between March, 1966, and June, 1985, 23 women and 12 men underwent partial or total resection of apical petrous or clivus meningiomas at The National Hospital for Nervous Diseases. Presenting symptoms were typically of long duration (mean 29 months) and consisted primarily of gait disturbance, headache, hearing loss, and facial pain. Cranial nerve deficits, especially affecting the fifth, seventh, and eighth nerves, were observed in nearly every patient. Tumor size, but not location, was generally associated with degree of preoperative disability. Plain skull films were usually unremarkable, but computerized tomography (CT) proved highly accurate in determining tumor location and size. A characteristic pattern of vascular displacement was seen on vertebral angiograms, although blood supply to the tumors was derived primarily from branches of the internal and external carotid arteries.
Subtotal or total resection was undertaken in all cases; nine patients required adjunctive cerebrospinal fluid shunting procedures. Although surgical techniques evolved during the course of the 20-year study, a combined supra- and infratentorial approach proved a relatively safe and effective means of surgical treatment. New or worsened postoperative deficits, especially cranial nerve palsies, and complications in the immediate postoperative period frequently resulted in temporary deterioration of the clinical status during this period; the total operative mortality rate was 9%. Follow-up periods ranged up to 9 years; 70% of patients resumed an independent existence, and none is known to have required subsequent tumor surgery. The size of the lesion was the only significant factor in determining outcome. These data suggest that meningiomas of the clivus and apical petrous bone can be accurately diagnosed by CT and three-vessel angiography, and effectively treated by microsurgical resection.
Neurosurgical complications after apparently minor head injury
Authors: Dacey Ralph G. , Alves Wayne M. , Rimel Rebecca W. , Winn H. Richard , Jane John A. 
Published: May 2009

✓ A small number of patients with an apparently minor head injury will develop a life-threatening intracranial hematoma that must be rapidly detected and removed. To assess the risk of a significant intracranial neurosurgical complication after apparently minor head injury, the authors collected data prospectively on 610 patients who had sustained a transient posttraumatic loss of consciousness or other neurological function and who had a Glasgow Coma Scale (GCS) score of 13, 14, or 15 in the emergency room. Skull x-ray films were obtained in 583 patients, 66 of whom (10.8% of the study population) had cranial fractures. Eighteen of the 610 patients (3.0%) required a neurosurgical procedure. Three acute subdural hematomas, one epidural hematoma, and one traumatic intracerebral hematoma required craniotomy. Of the 66 patients who had skull fracture, 7.6% required a craniotomy for intracranial hematoma. Thirteen (19.7%) of the 66 patients with skull fracture required an operative procedure as compared to five (1.0%) of the 517 patients without skull fracture. Two patients with a normal GCS score of 15 and normal skull x-ray films subsequently underwent operative treatment.
The cost of three alternative management schemes for these patients was estimated. A 50% reduction in cost of management could be effected by the use of computerized tomography (CT) scans (or possibly skull x-ray films) in determining which of the patients who are alert at the time of presentation should be admitted for observation. Several other conclusions can be drawn from this study. First, an initial GCS score between 13 and 15 does not necessarily indicate that a patient has sustained a trivial head injury, since 3% of such patients will require an operative procedure despite an initially normal level of alertness. Second, an abnormal skull x-ray film increases by a factor of 20 the probability that a patient will need neurosurgical treatment. Third, it is very unusual for patients who have a GCS score of 15 and a normal skull x-ray film to have a significant neurosurgical complication. Fourth, the alternative management schemes that depend on selective use of skull films and CT scans may significantly reduce the cost of caring for patients with minor head injury.
Primary malignant lymphoma of the central nervous system
Authors: Murray Kevin , Kun Larry , Cox James 
Published: May 2009

✓ Eleven patients with primary malignant lymphoma of the central nervous system (CNS) were treated at the Medical College of Wisconsin Affiliated Hospitals between 1964 and 1984. Three patients had a prior history of immunosuppressive therapy following renal transplantation. All patients had biopsy-proven disease and 10 of the 11 were treated with external radiation therapy. The doses to the primary tumor ranged from 34 to 59.4 Gray (Gy). Actuarial (life-table) survival rate was 82% at 1 year and 43% at 3 years. No recurrence was seen after 13 months.
Eighty-six reports totaling 693 cases of primary malignant lymphoma of the CNS were found in the literature. Of these, 308 cases were treated with a combination of surgery and irradiation. Overall survival at 5 years for those patients who received more than 50 Gy compared with less than 50 Gy to the primary tumor was 42.3% versus 12.8% (p < 0.05). Twenty-one patients survived longer than 5 years. Late relapse was notable, with 10 (47.6%) of 21 tumors recurring between 5 and 12.5 years after diagnosis. Based on this review, a minimum of 50 Gy radiation to the primary tumor is recommended. While no statement regarding the efficacy of craniospinal irradiation or chemotherapy can be made in view of the small numbers, the use of craniospinal irradiation and/or systemic chemotherapy should be considered for future trials.
Chronic expanding intracerebral hematoma
Authors: Pozzati Eugenio , Giuliani Giuliano , Gaist Giulio , Piazza Giancarlo , Vergoni Gilberto 
Published: May 2009

✓ The cases of 10 normotensive patients with chronic intracerebral hematomas are reported. The patients' median age at diagnosis was 42 years. The median duration of symptoms was 22 days. Seizures were thepresenting symptom in 50% of the cases. Computerized tomography almost consistently demonstrated ring-shaped lesions with mass effect and perifocal edema. Arteriography revealed that all but one of the lesions were avascular. All patients had superficial white matter lesions, mostly in the frontoparietal region. All patients were treated surgically. Most of the hematomas were encapsulated and contained blood in various stages of organization. The thick capsule consisted of an outer layer of collagenous tissue and an inner layer of granulation tissue. Occult cerebrovascular malformations were detected in two instances.
There were two deaths, both related to recurrent postoperative hemorrhage. This entity can present much like a brain malignancy and should be considered in the differential diagnosis of ring-shaped lesions whatever the clinical presentation. Strategies of treatment are discussed.
Cerebral perfusion pressure, intracranial pressure, and head elevation
Authors: Rosner Michael J. , Coley Irene B. 
Published: May 2009

✓ Previous investigations have suggested that intracranial pressure waves may be induced by reduction of cerebral perfusion pressure (CPP). Since pressure waves were noted to be more common in patients with their head elevated at a standard 20° to 30°, CPP was studied as a function of head position and its effect upon intracranial pressure (ICP).
In 18 patients with varying degrees of intracranial hypertension, systemic arterial blood pressure (SABP) was monitored at the level of both the head and the heart. Intracranial pressure and central venous pressure were assessed at every 10° of head elevation from 0° to 50°. For every 10° of head elevation, the average ICP decreased by 1 mm Hg associated with a reduction of 2 to 3 mm Hg CPP. The CPP was not beneficially affected by any degree of head elevation. Maximal CPP (73 ± 3.4 mm Hg (mean ± standard error of the mean)) always occurred with the head in a horizontal position. Cerebrospinal fluid pressure waves occurred in four of the 18 patients studied as a function of reduced CPP caused by head elevation alone. Thus, elevation of the head of the bed was associated with the development of CPP decrements in all cases, and it precipitated pressure waves in some. In 15 of the 18 patients, CPP was maintained by spontaneous 10- to 20-mm Hg increases in SABP, and pressure waves did not occur if CPP was maintained at 70 to 75 mm Hg or above.
It is concluded that 0° head elevation maximizes CPP and reduces the severity and frequency of pressure-wave occurrence. If the head of the bed is to be elevated, then adequate hydration and avoidance of pharmacological agents that reduce SABP or prevent its rise are required to maximize CPP.
Estimation of growth fraction with bromodeoxyuridine in human central nervous system tumors
Authors: Yoshii Yoshihiko , Maki Yutaka , Tsuboi Koji , Tomono Yuji , Nakagawa Kunio , Hoshino Takao 
Published: May 2009

✓ Twenty-five patients with tumors of the central nervous system received bromodeoxyuridine (BUdR), 200 mg/sq m, by intravenous infusion every 8 hours for 3 days before surgery. Excised tumor specimens were fixed in chilled 70% ethanol, embedded in paraffin, and cut into 6-µm sections. Each section was reacted with monoclonal antibodies against BUdR and stained with immunoperoxidase to identify nuclei that had incorporated BUdR. The growth fraction of each tumor was estimated by calculating the ratio of BUdR-positive nuclei to the total number of tumor cells in three to six microscopic fields in viable areas of the tumor. In seven cases, the tumor doubling time was measured from the serial computerized tomography scans and an attempt was made to estimate the cell cycle time.
The growth fractions ranged from 9.1% to 46.5% in malignant gliomas, 2.0% to 6.7% in low-grade gliomas, 11.2% to 43.2% in metastatic brain tumors, 0.8% to 1.9% in pituitary adenomas, 3.9% to 4.6% in acoustic neurinomas, and 6.2% to 8.2% in meningiomas and cerebellar hemangioblastomas. The estimated cell cycle time was 5 to 12 days in most malignant gliomas and brain metastases; however, the actual cell cycle time should be substantially shorter because cell loss was not considered in the calculation. Although the growth fraction appeared to correlate with the biological malignancy of each tumor, the tumor doubling time did not reflect growth potential. It is possible that unpredictable cell loss plays an important role in tumor growth at certain sizes. Therefore, the cell cycle times calculated in this study are considerably overestimated and should be interpreted with caution.