bluuebunny/crossref_metadata_2025_split huggingface dataset:
Management of obstructive hydrocephalus secondary to posterior fossa tumors by steroids and subcutaneous ventricular catheter reservoir
Authors: Schmid Urs D. , Seiler Rolf W. 
Published: May 2009

✓ In 61 patients (38 adults and 23 children) with surgically treatable tumors of the posterior fossa and obstructive hydrocephalus the following treatment for hydrocephalus was employed: 1) a high dose of steroids was given after diagnosis; 2) a frontal ventricular catheter with a subcutaneous fluid reservoir (Rickham) was inserted within 2 to 5 days; 3) a temporary external ventricular drainage system was attached to the reservoir if, despite the steroids, intracranial pressure was over 30 cm H2O; and 4) tumor excision was performed within 5 days to reopen the cerebrospinal fluid (CSF) pathways. In view of the wide range of potential complications, it was decided not to use a shunt before craniotomy. A shunt was inserted only if the CSF pathways remained obstructed after tumor removal. With this regimen, 93% of all patients (100% of the adults and 83% of the children) were shunt-free after the operation, without fatal complications. The infection rate was 4.9%.
It was concluded that the severity of symptoms of raised intracranial pressure from hydrocephalus, the intraventricular pressure, and the size or location of the tumor prior to surgery do not have prognostic value as to which patients will require a shunt after surgery.
Effect of difluoromethylornithine on the antiglioma therapeutic efficacy of intra-arterial BCNU
Authors: Cohen Alan R. , Pietronigro Dennis D. , Cravioto Humberto , Flamm Eugene S. 
Published: May 2009

✓ In an attempt to improve glioma management, an animal model was developed to evaluate the therapeutic efficacy of intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Furthermore, the model was used to study the antitumor activity of D,L-alpha-difluoromethylornithine (DFMO), a polyamine-biosynthesis inhibitor, used both as a single agent and in combination with intra-arterial BCNU.
An N-methylnitrosourea-induced gliosarcoma (T9) was transplanted stereotaxically into the right caudate nucleus of male Fischer 344 rats. Animals receiving a single low-dose (5 mg/kg) intracarotid injection of BCNU 9 days following tumor implantation had a 57% increase in life span compared with untreated control rats (p < 0.001). Intracarotid drug delivery was more effective than systemic (intraperitoneal) administration of the same dose of BCNU.
When given as a single agent, DFMO demonstrated dose-dependent effectiveness. As part of a combined regimen, DFMO enhanced the antitumor therapeutic activity of both systemic (intraperitoneal) and intra-arterial BCNU. Survival times of animals receiving combined DFMO and intra-arterial BCNU were almost double those of untreated controls, and were significantly better than survival times of animals receiving combined DFMO and intraperitoneal BCNU. These findings suggest methods to optimize current clinical chemotherapy for glioma.
Pathology of invasive pituitary tumors with special reference to functional classification
Authors: Scheithauer Bernd W. , Kovacs Kalman T. , Laws Edward R. , Randall Raymond V. 
Published: May 2009

✓ Pituitary adenomas may remain intrasellar or infiltrate dura and bone. Invasive adenomas are not considered to be malignant; in biological behavior they are between non-infiltrative adenomas and pituitary carcinomas. The latter are defined as tumors with subarachnoid, brain, or systemic metastasis. Invasion may be defined radiologically, operatively, or histologically. On the basis of operatively assessed tumor size and gross invasion of dura and bone as well as immunocytochemical and ultrastructural analysis of 365 pituitary adenomas, the following data were obtained. There were 23 growth hormone (GH)-cell adenomas: 14% microadenomas and 86% macroadenomas; their overall frequency of invasion was 50%. There were 24 prolactin (PRL)-cell adenomas: 33% microadenomas and 67% macroadenomas, with an overall frequency of invasion of 52%. Mixed GH-cell and PRL-cell adenomas were found in 35 cases; 26% were microadenomas and 74% were macroadenomas, and the overall frequency of invasion was 31%. Sixty patients had adrenocorticotropic hormone (ACTH)-cell adenomas (Cushing's disease): 87% microadenomas and 13% macroadenomas; the overall frequency of invasion was 25% (in 8% of microadenomas and 62% of macroadenomas). Twenty patients had ACTH-cell adenomas (Nelson's syndrome): 30% microadenomas and 70% macroadenomas; the overall frequency of invasion in these cases was 50% (in 17% of microadenomas and 64% of macroadenomas). Silent ACTH-cell adenomas, 100% macroadenomas, were found in 11 patients, with an 82% frequency of invasion. There were 32 follicle-stimulating and luteinizing hormone adenomas, all macroadenomas, with a frequency of invasion of 21%. Four patients had thyroid-stimulating hormone adenomas, all macroadenomas, with a 75% frequency of invasion. Null-cell adenomas were found in 93 cases: 2% microadenomas and 98% macroadenomas, with a frequency of invasion of 42%. There were 63 plurihormonal adenomas (GH, PRL, glycoprotein): 25% microadenomas and 75% macroadenomas, with a 50% overall frequency of invasion.
Based on this study, and on their usual frequency of occurrence, the estimated rate of gross invasion by pituitary adenomas of all types is approximately 35%. It is concluded that immunocytochemical and ultrastructural characteristics of pituitary adenomas reflect the tendency of these tumors to infiltrate and hence may be of prognostic significance.
Diagnosis and management of pediatric brain-stem gliomas
Authors: Stroink Ann R. , Hoffman Harold J. , Hendrick E. Bruce , Humphreys Robin P. 
Published: May 2009

✓ The authors reviewed the cases of 49 children, ranging in age from 9 months to 15 years, who were diagnosed by computerized tomography (CT) as having brain-stem glioma. Four distinct groups of brain-stem gliomas were identified based on CT scan characteristics: Group I included isodense contrast-enhancing tumors that were dorsally exophytic into the fourth ventricle; Group II(a) included hypodense nonenhancing intrinsic tumors of the brain stem; Group II(b) included intrinsic tumors of the brain stem with hyperdense exophytic components extending ventrally and laterally into the cerebellopontine and prepontine cisterns; Group III included intrinsic cystic tumors with contrast-enhancing capsules; and Group IV included focally intrinsic tumors of the brain stem that were isodense and enhanced brightly on administration of contrast medium.
The clinical presentation, efficacy of surgical intervention, pathology, and prognosis of these tumors were correlated within these groupings. Eleven patients had Group I tumors, all of which were surgically resected; 10 of the 11 lesions were proven to be low-grade gliomas. These patients had an excellent prognosis; 10 of the 11 survived, with a mean follow-up period of 4.5 years. There were 18 patients with Group II(a) tumors; although tumor biopsy was attempted on eight of these, pathological diagnosis at the time of surgery was made in only one case. These patients did poorly; the mean survival time was 6.2 months. The seven Group II(b) tumor patients demonstrated a similarly poor prognosis: all of them died within 23 months of diagnosis, with a mean survival time of 12 months. Only two of six patients undergoing biopsy had sufficient tissue for histological verification. Three of the four patients with Group III tumors died; their mean survival time was 11.5 months. Successful histological examination was carried out in all four cases. The nine Group IV tumor patients did reasonably well; seven of these patients remain alive, with a mean follow-up period of 2.3 years. Histological diagnosis was obtained in three of the seven patients who were explored in this group. This classification system has proven to be of value in determining prognosis and efficacy of surgical intervention.
Complications associated with the halo-vest
Authors: Glaser John A. , Whitehill Richard , Stamp Warren G. , Jane John A. 
Published: May 2009

✓ The cases of all patients treated with halo-vests for cervical trauma at the University of Virginia since 1977 were analyzed retrospectively. A standardized chart and radiographic review protocol were used to identify complications associated with the use of the orthosis. Two hundred and forty-five patients satisfied the criteria for inclusion in the study. No patient developed or suffered progression of a neurological deficit while immobilized. Complications included: pneumonia causing death (one patient); loss of reduction or progression of the spinal deformity (23 patients); spinal instability following orthotic immobilization for 3 months (24 patients); pin-track infection (13 patients); migration of anteriorly placed iliac-strut grafts (two patients); cerebrospinal fluid leakage from a halo pinhole (one patient); and miscellaneous (seven patients).
The findings indicate several conclusions. 1) The halo-vest protects patients with cervical instability from neurological injury. 2) It does not absolutely immobilize the cervical spine nor does it prevent progressive deformity of malpositioned strut grafts. 3) Even after a 3-month orthotic treatment period, surgery may be required on ligamentous and osseous injuries to provide spinal stability. 4) Elderly kyphotic patients may require custom-made vests. 5) A small subset of patients exists for whom the confining nature of the halo-vest is intolerable for 3 months.
Normal computerized tomography scans in severe head injury
Authors: Lobato Ramiro D. , Sarabia Rosario , Rivas Juan J. , Cordobes Francisco , Castro Servando , Muñoz Maria J. , Cabrera Antonio , Barcena Alejandro , Lamas Eduardo 
Published: May 2009

✓ The authors analyze the clinical course of 46 severely head-injured patients who had completely normal computerized tomography (CT) scans through the immediate posttraumatic period (1 to 7 days after trauma). These patients represent 10.2% of a consecutive series of 448 cases of severe head injuries and two-thirds of the cases showing a normal CT scan on admission (the other one-third of the cases developed new pathology). The usual course in these 46 patients after the initial coma was toward progressive neurological improvement, and 35 patients (76%) achieved a functional level of survival. Nine patients (19.5%) remained comatose for several weeks and developed severe disability. There were two fatalities due to medical complications. The final outcome was more closely related to the duration of coma (the longer the duration the worse the result) than to the initial Glasgow Coma Scale (GCS) score. In fact, 26% of the patients in the lower GCS score ranges (3 to 4 points) made a good recovery and 46% developed moderate disability only. These findings indicate that the grim prognostic significance of deep posttraumatic coma is tempered in the presence of a normal scan. However, the absence of CT abnormalities in severely head-injured patients cannot be equated with a good prognosis because in one-fifth of the cases serious permanent disability develops.
Sustained elevation of the intracranial pressure (ICP) was not seen in these patients, indicating that ICP monitoring may be omitted in cases with a normal scan. However, since one-third of the patients with a normal admission scan developed new pathology within the first few days of injury, a strategy for control scanning is recommended. Control CT scans performed more than 6 months after injury showed a significantly higher incidence of brain atrophy in patients developing permanent disability than in those who made a good recovery.
Extensibility of the lumbar and sacral cord
Authors: Tani Satoshi , Yamada Shokei , Knighton Robert S. 
Published: May 2009

✓ Tethered spinal cord, or tethered cord syndrome, describes a disorder manifested by progressive motor and sensory deficit in the legs and by incontinence. Tethered cord syndrome occurs when the elongated spinal cord is anchored by a thick filum terminale or other pathological structures. The underlying mechanism is impairment of oxidative metabolism in the lumbosacral cord. The authors studied the extensibility of various parts of lumbar, sacral, and coccygeal segments in experimental animals and correlated this with the oxidative metabolism in these segments.
The filum terminale possesses far greater extensibility than any spinal cord segments and functions as a buffer in preventing the cord from overstretching. The lumbar, sacral, and coccygeal segments elongate under traction only below the attachment of the lowest pair of dentate ligaments. The lower the cord segment, the greater the percentage of elongation in spite of limited elasticity of the cord tissue; this greater percentage of elongation of the spinal cord correlates with increasing impairment of the oxidative metabolism and more severe neurological deficit. These findings explain such symptoms and signs as motor and sensory deficits in the legs associated with the human tethered cord syndrome, and correspond with the high clinical incidence of incontinence.
The lower spinal cord segments elongated promptly within 3 seconds after the start of traction. This implies that repeated acute hyperextension and hyperflexion, as occurs in humans, may accentuate oxidative metabolic changes that have already been caused by chronic cord tethering. The authors conclude that the elongation of the spinal cord under traction parallels the degree of metabolic dysfunction.
Percutaneous automated discectomy: a new method for lumbar disc removal
Authors: Maroon Joseph C. , Onik Gary 
Published: May 2009

✓ A new technique for percutaneous lumbar disc removal is described. The specially designed 2-mm blunt-tipped suction/cutting probe (nucleotome) is similar to the automated vitrectomy instrumentation used by ophthalmic surgeons. The procedure is performed under local anesthesia, with the patient in the prone position and with fluoroscopic guidance. The nucleotome is inserted into the appropriate disc space with specially designed instrumentation, guided by landmarks similar to those used in needle placement for chemonucleolysis.
The technique has been evaluated in 20 patients with herniated discs (one at the L3-4 level and 19 at the L4-5 level) confirmed by myelography and/or computerized tomography scans after all conservative therapy for primarily radicular pain had failed. From 1 to 7 gm of disc material was removed in an average total operative time of approximately 1 hour. Eighty percent of the patients had good to excellent results in a short-term follow-up period of 6 months. Four patients subsequently required standard surgical excision of free disc fragments. No significant complications occurred. The procedure is contraindicated in patients with extruded or free fragments of disc in the spinal canal or in patients with herniations at the L5-S1 level pending development of additional instrumentation for insertion at that level. More extensive long-term studies are needed to further evaluate this procedure.
Hormone production in clinically nonfunctioning pituitary adenomas
Authors: Black Peter McL. , Hsu Dora W. , Klibanski Anne , Kliman Bernard , Jameson J. Larry , Ridgway E. Chester , Hedley-Whyte E. Tessa , Zervas Nicholas T. 
Published: May 2009

✓ Pituitary tumors in which no excess hormone secretion can be identified clinically have been considered as nonfunctioning or null-cell adenomas. Immunocytochemical data presented here suggest that many of these tumors contain subunits of the glycoprotein hormones.
Of 160 patients referred for pituitary surgery, 37 (23%) had no evidence of excess hormone secretion on preoperative endocrine evaluation. Immunocytochemical staining of these tumors was carried out using antibodies specific for prolactin, growth hormone, adrenocorticotropic hormone, the beta subunits of luteinizing hormone (β-LH), follicle-stimulating hormone (β-FSH), and thyroid-stimulating hormone (β-TSH), and the alpha subunit.
One or more of these pituitary hormones were detected in 73% of cases. The alpha and beta subunits were detected most frequently, being found in 68% of cases; 27% had staining for one or more beta subunits and 37.9% had staining for both alpha and beta subunits. The incidence was: β-FSH in 58%, β-LH in 47%, β-TSH in 33%, and the alpha subunit in 42%. Staining for multiple glycoprotein hormones was common (52%), and mixed glycoprotein hormones and prolactin cell types were found in 16% of cases. These data suggest that most apparently nonfunctioning pituitary tumors contain immunoreactive hormones and the majority of these are subunits of the glycoprotein hormones. Since the glycoprotein hormone beta subunits must combine with the alpha subunit to produce biologically active hormones, the production of the subunits alone may not have endocrine manifestations.
Effect of dexamethasone on experimental brain abscess
Authors: Schroeder Kurt A. , McKeever Paul E. , Schaberg Dennis R. , Hoff Julian T. 
Published: May 2009

✓ Dexamethasone has been used to manage brain edema in patients with intracranial abscess. However, its administration has often been delayed or avoided for fear of adverse effects upon normal host responses to infection. An experimental model of brain abscess in the rat was developed to determine if dexamethasone produced adverse effects on immune competence and collagen deposition in the region of the abscess. Sprague-Dawley rats were inoculated with Staphylococcus aureus and treated intraperitoneally each day with either dexamethasone (0.25 mg/kg) or saline solution. Surviving animals were sacrificed at 4, 8, 12, or 18 days after treatment. The brains were examined grossly for abscess formation and microscopically for intensity of the inflammatory response, abscess diameter, and wall thickness.
There were no differences in mortality rates, abscess production rates, or abscess diameters when groups were compared. The intensity of inflammatory response was similar in both groups. In the group sacrificed 8 days after inoculation, a delay in collagen deposition was apparent, manifested as a thinner abscess wall in the experimental group (mean: 17.8 μ in dexamethasone-treated animals and 85 μ in saline-treated control animals: p = 1.0041). At 12 and 18 days after inoculation, there was no difference in abscess wall thickness between the control and experimental groups. Therapeutic doses of dexamethasone had little effect on mortality rates, incidence of abscess production, or intensity of inflammatory response in the experimental animals. Thus, dexamethasone did cause a delay in collagen deposition in the walls of experimental brain abscesses, but wall thickness 18 days after inoculation was not affected.
Pain relief by electrical stimulation of the periaqueductal and periventricular gray matter
Authors: Young Ronald F. , Chambi V. Israel 
Published: May 2009

✓ Pain relief following stimulation of the periaqueductal gray matter (PAG) or periventricular gray matter (PVG) in man has been ascribed to stimulation-induced release of endogenous opioid substances. Forty-five patients were studied and followed for at least 1 year after placement of chronic stimulating electrodes in the PAG or PVG to determine if pain relief due to stimulation could be ascribed to an endogenous opioid mechanism. Three criteria were assessed: 1) the development of tolerance to stimulation; 2) the possibility of cross-tolerance to morphine; and 3) reversibility of stimulation-induced pain relief by the opiate antagonist naloxone. Sixteen patients (35.6%) developed tolerance to stimulation, that is, they obtained progressively less effective pain relief. Twelve (44.4%) of 27 patients undergoing stimulation of the thalamic sensory relay nuclei for treatment of chronic pain (a presumably non-opioid mechanism) also developed tolerance. Morphine sulfate was administered in a blind, placebo-controlled protocol to 10 patients who had become tolerant to PAG-PVG stimulation and none showed evidence of cross-tolerance. Fifteen of 19 patients, already tolerant to morphine at the time of PAG-PVG electrode implantation, experienced excellent pain relief by stimulation, also indicating a lack of cross-tolerance. Twenty-two patients who experienced excellent pain relief from chronic PAG-PVG stimulation received intravenous naloxone in a double-blind, placebo-controlled protocol. Pain intensity as assessed by the visual analog scale was increased to the same degree by both placebo and naloxone. Eight patients showed no increase in pain intensity with either placebo or naloxone.
Although tolerance to PAG-PVG stimulation developed in these patients, the frequency of tolerance was similar to that seen in patients undergoing thalamic sensory nuclear stimulation. Since the latter technique presumably relieves pain by a non-opioid mechanism, the development of tolerance to PAG-PVG stimulation does not, in itself, confirm an opioid mechanism. Cross-tolerance between PAG-PVG stimulation and morphine was not seen and cross-tolerance to PAG-PVG stimulation in patients already tolerant to morphine was rare. The pain-relieving effect of PAG-PVG stimulation was reversed to an approximately equal degree by naloxone and placebo. The authors do not believe that, in most patients, pain relief elicited by PAG-PVG stimulation depends on an endogenous opioid mechanism. It appears that other, non-opioid mechanisms are primarily responsible for such pain relief.
Cerebral blood flow in patients with normal-pressure hydrocephalus before and after shunting
Authors: Vorstrup Sissel , Christensen John , Gjerris Flemming , Sørensen P. Soelberg , Thomsen Anne Marie , Paulson Olaf B. 
Published: May 2009

✓ Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission tomography in 17 demented patients with normal-pressure hydrocephalus before and after shunt treatment. All patients had a decreased conductance to outflow (Cout) of cerebrospinal fluid as measured by lumboventricular perfusion (COut < 0.12 ml ⋅ mm Hg−1 ⋅ min−1). Computerized tomography (CT) scanning, clinical assessment, and neuropsychological grading were performed pre- and postoperatively. The preoperative CBF studies revealed abnormal flow patterns in all patients. Fourteen patients showed moderate-sized, large, or very large central low-flow areas, and four patients had reduced flow bilaterally in the occipital and contiguous temporoparietal regions.
After shunting, six patients had a significant reduction in the size of the central low-flow area on the CBF map, agreeing well with the changes of ventricular size on the CT scan. All six patients showed an improvement in either clinical or neuropsychological grading. In 10 of the remaining 11 patients flow patterns were essentially unchanged; one patient deteriorated further. Four of these 11 patients improved on postoperative clinical or neuropsychological testing. Thus, a positive correlation was found between the changes in CBF and the reduction of the ventricular size on the CT scan, but changes in CBF as measured by the present technique did not accompany improvement in the functional state in all patients.