bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of acquired arteriovenous fistulas in rats due to venous hypertension
Authors: Terada Tomoaki , Higashida Randall T. , Halbach Van V. , Dowd Christopher F. , Tsuura Mitsuharu , Komai Norihiko , Wilson Charles B. , Hieshima Grant B.
Published: May 2009

✓ Dural sinus thrombosis has been hypothesized as a possible cause of dural arteriovenous fistulas (AVF's). The pathogenesis and evolution from thrombosis to actual development of an AVF are still unknown. To study dural fistula formation, a surgically induced venous hypertension model in rats was created by producing an arteriovenous shunt between the carotid artery and the external jugular vein. The external jugular vein beyond the anastomosis was ligated 2 to 3 months after surgery and angiography was performed to identify any new acquired AVF's.

Forty-six male Sprague-Dawley rats, each weighing approximately 300 gm, were used for this study. In Group I, 22 rats underwent a common carotid artery anastomosis to the external jugular vein, which is the largest draining vein from the transverse sinus via the posterior facial vein, followed by proximal external jugular vein ligation. In Group II, 13 rats underwent the same surgical procedure, followed by contralateral posterior facial vein occlusion. Group III served as the control group, in which 11 rats underwent only unilateral external jugular vein occlusion with or without contralateral posterior facial vein occlusion. The shunts in Groups I and II were ligated at 2 to 3 months following surgery, and transfemoral angiography was performed immediately before and after occlusion.

New acquired AVF's had developed in three rats (13.6%) in Group I, three rats (23.1%) in Group II, and no rats (0%) in Group III. One of these newly formed fistulas was located at the dural sinus, analogous to the human dural AVF. The other five were located in the subcutaneous tissue, including the face and neck. The dural AVF in the rat was present on follow-up angiography at 1 week after the bypass occlusion. It is concluded that chronic venous hypertension of 2 to 3 months' duration, without associated venous or sinus thrombosis, can induce new AVF's affecting the dural sinuses or the subcutaneous tissue.
Lymphocytic hypophysitis
Authors: Naik Ramachandra G. , Ammini Ariachery , Shah Pankaj , Sarkar Chitra , Mehta Veer Singh , Berry Manorama
Published: May 2009

✓ A case of lymphocytic hypophysitis is described in a patient presenting with panhypopituitarism 8 years after her last childbirth. The patient developed headache, vomiting, and diplopia (due to palsy of the right lateral rectus muscle) 7 months after delivery of her last baby. The diplopia disappeared after a few days with symptomatic treatment, and the headache and vomiting decreased in intensity with analgesic therapy. Eight years later the patient developed symptoms suggestive of hypoadrenalism, hypothyroidism, and amenorrhea. Investigations revealed panhypopituitarism with a pituitary mass lesion. Repeat evaluation 1 year later demonstrated no change in the size of the pituitary gland. The patient underwent transsphenoidal surgery with a provisional diagnosis of pituitary adenoma. Histological examination of the resected gland revealed evidence of lymphocytic hypophysitis. Symptoms suggestive of a pituitary mass lesion were noted during the peripartum period, but features of hypopituitarism developed much later. Such a long latent period has not been reported before. This report also highlights the fact that glandular enlargement may persist for many years after the onset of lymphocytic hypophysitis.
Neurosurgery at the Mount Sinai Hospital
Authors: Oppenheim Jeffrey S.
Published: May 2009

✓ The Mount Sinai Hospital was founded in 1852 under the name “The Jews' Hospital.” Neurosurgery at Mount Sinai Hospital can be traced to the work of Dr. Charles Elsberg. In 1932, the Department of Neurosurgery was created under the direction of Dr. Ira Cohen. The history of neurosurgery at the Mount Sinai Hospital is recounted.
History of the Journal of Neurosurgery, 1965–1980
Authors: Schwartz Henry G.
Published: May 2009

✓ The author, who was Editor of the Journal of Neurosurgery from 1975 to 1985, recalls the history of the Journal during the 15 years beginning in 1965, when Dr. Louise Eisenhardt resigned as its first Editor. In an addendum, he presents some thoughts on the future of neurosurgery and the role the Journal should play in it.
Percutaneous cervical cordotomy: a review of 181 operations on 146 patients with a study on the location of “pain fibers” in the C-2 spinal cord segment of 29 cases
Authors: Lahuerta Juan , Bowsher David , Lipton Simpson , Buxton Peter H.
Published: May 2009

✓ The authors present a review of 146 patients who underwent 181 percutaneous cervical cordotomies for intractable pain. In addition, an anatomical-clinical correlation was carried out for 29 of these patients. It was found that the fibers subserving pain sensation in the C-2 segment lie in the anterolateral funiculus between the level of the denticulate ligament and a line drawn perpendicularly from the medial angle of the ventral gray-matter horn to the surface of the cord. The best analgesic results have been obtained by creating lesions that extend 5.0 mm deep to the surface of the cord and destroy about 20% of the hemicord. There is a somatotopic organization with sacral fibers running ventromedially and cervical fibers running dorsolaterally. The authors believe that the ascending fibers subserving the distinct sensations of pain induced by tissue damage and pinprick, although mixed (overlapping) in the anterolateral funiculus of the spinal cord, are physiologically distinct from one another. Whereas some cordotomies, both in the current series and as reported in the literature, may affect these functions differentially, optimum pain relief seems to be obtained only when pinprick sensation is also abolished in the affected segments.

Evoked pain sensation is not abolished by cordotomy, but its threshold is greatly raised. When pathological pain is completely abolished, so is pinprick sensation. However, in a number of cases where pathological pain was only partially alleviated, pinprick sensation remained intact. The significance of these and other cases reported in the literature is discussed. The importance of clinically distinguishing between pain caused by tissue damage and pinprick sensation is emphasized, as well as that between return of pre-existing or new tissue-damage pain and painful dysesthesia.
Quality of long-term survival in young children with medulloblastoma
Authors: Johnson Dennis L. , McCabe Mary Ann , Nicholson H. Stacy , Joseph Amy L. , Getson Pamela R. , Byrne Julianne , Brasseux Cynthia , Packer Roger J. , Reaman Gregory
Published: May 2009

✓ The reported success of treatment for children with medulloblastoma must be balanced against the effect that treatment has on the quality of life of long-term survivors. The outcome of long-term survivors reported in previous studies has been conflicting. The authors evaluate the mental and behavioral skills of a group of medulloblastoma survivors from their institution, all of whom had survived for more than 5 years postdiagnosis. A review of the institutional records yielded 32 patients. Twenty-three families were interviewed by telephone and, of these, 13 subjects came to the hospital for detailed neuropsychological and neurological evaluations.

Intelligence quotient (IQ) was less than 90 for all participants tested, and patients diagnosed before the age of 3 years had lower IQ scores on average than those diagnosed later. Mean IQ and achievement test scores in reading, spelling, and mathematics were all higher in survivors who had undergone shunting. Achievement test results were often not in accord with intellectual potential, and individual intellectual skills varied widely. Perceptual-motor task performance was below average in more than 50% of the participants, but motor dexterity was more severely affected than perception. Problems in learning and a delay in both physical growth and development were seen in a majority of participants.

This study directs attention to the serious difficulties faced by long-term survivors of medulloblastoma and their families, and underscores the importance of routine neuropsychological testing. Moreover, the study provides further impetus to seek alternatives to irradiation in the treatment of malignant brain tumors.
Stereotactic radiosurgery for acoustic nerve tumors in patients with useful preoperative hearing: results at 2-year follow-up examination
Authors: Ogunrinde Olusola K. , Lunsford L. Dade , Flickinger John C. , Kondziolka Douglas
Published: May 2009

✓ Twenty patients with acoustic nerve tumors (mean diameter ≤ 30 mm) and useful preoperative hearing were examined 2 years after stereotactic radiosurgery to determine the effectiveness of the surgery in the control of tumor growth and the preservation of cranial nerve function. Results showed tumor volume stabilization (12 cases) or reduction (seven cases) was achieved in a total of 19 patients (95%). Useful hearing (defined as Gardner and Robertson Class I or II) preservation was obtained in 100% of cases immediately postoperatively, 50% at 6 months, and 45% at both 1 and 2 years. Two years after stereotactic radiosurgery, facial nerve function was preserved in 90% of patients and 75% continued to have normal trigeminal nerve function. All patients returned to and maintained their preoperative functional status within 3 to 5 days after radiosurgery.

These findings indicate that stereotactic radiosurgery with multiple isocenters and narrow radiation beams is a safe and effective management strategy for progressive acoustic nerve tumors. Auditory, facial, and trigeminal nerve function can be preserved in most patients. Prevention of further growth and preservation of cranial nerve function appear to be satisfactory goals in the current management of patients with acoustic neuromas.
Same-day microsurgical arthroscopic lateral-approach laser-assisted (SMALL) fluoroscopic discectomy
Authors: Savitz Martin H.
Published: May 2009

✓ The 2-year experience of one neurosurgeon with Kambin's orthopedic instruments and frame for arthroscopic microdiscectomy is reported. Arthroscopy using a unilateral approach and monoportal technique is a valuable adjunct to fluoroscopic monitoring. One hundred patients underwent same-day microsurgical arthroscopic lateral-approach laser-assisted (SMALL) fluoroscopic discectomy. In addition, suspected spinal tumors in three patients were treated by biopsy and infection of the disc space was drained in one. A prototype operating discoscope was employed for delivery of the neodymium:yttrium-aluminum-garnet laser beam to assist with hemostasis. Seventy-five “ideal” cases were identified that exhibited the following features: 1) up to a 6-month history of unilateral sciatica symptoms, which responded to bed rest; 2) mechanical signs of nerve root irritation when the patient was erect; 3) computerized tomography or magnetic resonance imaging studies interpreted as showing one protruding or prolapsed disc without extrusion; 4) no segmental spondylosis at the level of a herniated nucleus pulposus; 5) no motor weakness; 6) no prior disc surgery; 7) no obesity; and 8) no diabetes mellitus. Twenty-five “nonideal” cases failed to meet one or more of the above criteria. Good outcome rates were not substantially different in the two groups, success being judged in part by patient satisfaction. Complete success was evidenced in two-thirds of cases by early return to work, but improvement was also determined by increased mobility and a reduction in pain medication from narcotic to analgesic agents. Three patients underwent repeat surgery (laminotomy), but only one improved. Two years has provided sufficient clinical experience to determine that a percutaneous endoscopic procedure under neuroleptanalgesia may become a significant surgical alternative.
Temporal characteristics of radiosurgical lesions in an animal model
Authors: Blatt David R. , Friedman William A. , Bova Frank J. , Theele Daniel P. , Mickle J. Parker
Published: May 2009

✓ To characterize the temporal course of radiosurgical lesions, 19 cats were irradiated in an animal linear accelerator radiosurgical device. The animals were followed clinically and, at 3.5, 6, 12, 18, 23, 29, and 63 weeks, were studied with gadolinium-enhanced magnetic resonance (MR) imaging. They were then sacrificed after Evans blue dye perfusion, and gross pathological and histopathological studies were performed.

Mild neurological deficits developed between 3.5 and 4.5 weeks, correlating with the onset of mass effect both grossly and radiographically and with the maximum amount of white matter edema on T2-weighted MR imaging and microscopic examination. Clinical improvement occurred within several weeks as these resolved. The lesions were of similar size at all time intervals. Gadolinium-enhanced MR imaging demonstrated lesions with peripheral areas of enhancement and central nonenhancing regions which correlated histologically with areas of vascular proliferation and radiation necrosis, respectively. In the early lesions at 3.5 and 6 weeks, necrosis and edema were predominant. From 12 to 29 weeks, an intermediate stage was observed, with resorption of the necrotic debris as evidenced by progressive cavitation and microglial response and by increased perilesional vascularity. At 63 weeks, resorption was still taking place, but gliosis and diminution of the vascular response were seen.
Analysis of cytokine receptor messenger RNA expression in human glioblastoma cells and normal astrocytes by reverse-transcription polymerase chain reaction
Authors: Tada Mitsuhiro , Diserens Annie-Claire , Desbaillets Isabelle , de Tribolet Nicolas
Published: May 2009

✓ To elucidate which cytokine receptors may be expressed by human glioblastoma and normal astrocytic cells, the presence of messenger ribonucleic acid (RNA) for a number of cytokine receptors was examined in 16 glioblastoma cell lines and adult and fetal astrocytes. A complementary deoxyribonucleic acid copy of total RNA was synthesized and amplified with specific primers using the polymerase chain reaction method. The receptors studied were interleukin (IL)-1 receptor type I (IL-1RI) and type II (IL-1RII), p75 and p55 tumor necrosis factor (TNF) receptors (p75TNFR and p55TNFR), interferon (IFN)-α/β and -γ receptors (IFN-α/βR and IFN-γR), granulocyte-macrophage (GM) colony-stimulating factors receptor α subunit (GM-CSFR), G-CSF receptor (G-CSFR), M-CSF receptor (c-fms, M-CSFR), stem cell factor receptor (c-kit, SCFR), IL-6 receptor (IL-6R), and IL-8 receptor (IL-8R). Transcripts for IL-1RI, p55TNFR, IFN-α/βR, and IFN-γR were present in all cell lines. The presence of IL-1RII, p75TNFR, GM-CSFR, M-CSFR, SCFR, IL-6R, and IL-8R was identified in 13, eight, seven, eight, 14, three, and one cell lines, respectively. Normal astrocytes were positive for IL-1RI, p75TNFR, p55TNFR, IFN-α/βR, IFN-γR, M-CSFR, and SCFR, showing a similarity to glioblastoma cells. Expression of IL-1RII was observed in adult astrocytes but not in fetal astrocytes. Furthermore, gene expression was assessed in normal brain tissue and 11 glioblastoma tissue specimens. The normal brain tissue expressed IL-lRI, IL-1RII, IFN-α/βR, M-CSFR, and SCFR. Of the 11 glioblastoma tissue specimens, IL-1RI was positive in 11, IL-1RII in 10, p75TNFR in nine, p55TNFR in nine, IFN-α/βR in 10, IFN-γR in 10, GM-CSFR in two, G-CSFR in three, IL-8R in eight, and M-CSFR and SCFR in 11. These expressions were consistent with those in the cell lines, except for IL-8R. It is concluded that glioblastoma cells and normal astrocytes express a similar set of cytokine receptor genesin vitroandin vivo. Possible autocrine loops are suggested for IL-1α/IL-1RI, TNF-α/p55TNFR, IFN-β/IFN-α/βR, M-CSF/M-CSFR, and SCF/SCFR in glioblastomas.
The effect of irradiation on expression of HLA class I antigens in human brain tumors in culture
Authors: Klein Baruch , Loven David , Lurie Hedwig , Rakowsky Erica , Nyska Abram , Levin Israel , Klein Tirza
Published: May 2009

✓ The immunosuppressive effects of irradiation are well known; however, under certain circumstances irradiation also augments the local immune response by as yet undefined mechanisms. Because of the importance of HLA class I antigen in immune regulation and the fact that killing of tumor cells by cytotoxic T cells is HLA antigen-restricted, the authors studied HLA class I antigen expression in eight glioblastomas multiforme, four meningiomas, and four medulloblastomas. Twenty fragments of each tumor specimen were placed in short-term cultures immediately after resection. For each tumor, control Sample 1 was not irradiated, Sample 2 was irradiated on Day 1, and two groups of the remaining pieces of each tumor (specimens 3 to 10) were irradiated on two consecutive days. Escalating radiation doses were given, starting at 200 cGy/day for Sample 2 up to 1000 cGy/day for Sample 10. The total dose range was 200 to 2000 cGy. Corresponding nonirradiated tumor fragments served as controls. Four hours after irradiation, each sample was processed and stained for HLA class I antigen using the immunoperoxidase technique. The tumor cells were intensely stained in nonirradiated glioblastomas and meningiomas, whereas no staining was observed in medulloblastomas. In four of the eight glioblastomas and in all four meningiomas, irradiation augmented HLA class I antigen expression compared to controls. This effect was dose-dependent and was maximum in the 1200 cGy-treated specimens. No change was observed in the other four glioblastomas or in the medulloblastomas. The data suggest that irradiation does not decrease and may even induce HLA class I antigen expression in some brain tumors. This may be one of the mechanisms by which immunotherapy operates after irradiation. Further studies are required to elucidate optimum radiation doses and fractionation as well as optimum timing of immunotherapy.
Nerve and muscle blood flow during hindlimb ischemia and reperfusion in rats
Authors: Kinoshita Yoshihiro , Monafo William W.
Published: May 2009

✓ Animal models of peripheral nerve ischemia have yielded variable results. The question of whether postischemia re-establishment of blood flow to the nerves augments injury has not been examined. To study this question, the ipsilateral common iliac and femoral arteries were occluded with arterial snares for 3 hours in rats; 14-butanol tissue distribution was then used to measure blood flow in both sciatic and posterior tibial nerve trunks and in both biceps femoris muscles during occlusion and reperfusion. Clinical limb function was graded serially, with the undisturbed contralateral limb serving as the study control. Nerve blood flow was reduced throughout the ischemic period and was only 20% of the control value in the posterior tibial nerve. Muscle blood flow was unchanged. All rats had functional impairment, with an average limb function score of 7.5 (normal score < 2). During reperfusion, blood flow in the distal sciatic and posterior tibial nerves was approximately double that of control nerves at 2 hours, and muscle blood flow was also elevated. At 21 hours, tibial nerve blood flow was still twice that of the control nerve, but flows in the distal sciatic nerve and muscle were unchanged from control levels. Clinically, limb function improved progressively after reperfusion. It was concluded that nerve ischemia is attended by a relatively prolonged hyperemic flow response during reperfusion.
Long-term effects of radiation therapy for a catecholamine-producing glomus jugulare tumor
Authors: Pluta Ryszard M. , Ram Zvi , Patronas Nicholas J. , Keiser Harry
Published: May 2009

✓ A 42-year-old woman presented with otorrhea 22 years after extracranial resection of a norepinephrinesecreting glomus jugulare tumor with intravascular embolization and radiation therapy to the intracranial portion of the tumor. Tumor growth was arrested and was associated with a decrease in blood and urine norepinephrine levels. Extensive evaluation of the otorrhea, including computerized tomography-cisternography, gadoliniumenhanced magnetic resonance imaging, and arteriography showed marked diffuse necrosis of the temporal bone and skull base with limited tumor vascularity. Cerebrospinal fluid (CSF) collected from the right ear showed norepinephrine levels of 2975 pg/ml; plasma norepinephrine levels were normal. The precise site of CSF leakage could not be delineated. Exploration of the posterior fossa revealed a large dural defect at the anteromedial aspect of the petrous bone through which CSF flowed over the surface of the residual extradural glomus tumor. The defect was successfully sealed with a fascial patch. Postoperatively, CSF norepinephrine levels were normal and no further leakage was observed.
Granular cell tumor of the pituitary stalk
Authors: Lafitte Catherine , Aesch Bruno , Henry-Lebras Françoise , Fetissof Franck , Jan Michel
Published: May 2009

✓ The case is described of a granular cell tumor of the pituitary stalk in a 40-year-old woman with secondary amenorrhea. A computerized tomography scan showed a large contrast-enhancing mass, and T1-weighted magnetic resonance images demonstrated a tumor isointense to the brain parenchyma with nonhomogeneous enhancement after intravenous administration of gadolinium diethylenetriamine penta-acetic acid. Histopathological examination, especially immunocytochemical and electron microscopic studies, showed elements supporting an astrocytic origin for this type of tumor, a hypothesis advanced by many authors but still controversial.
Chronic diploic hematoma of the parietal bone
Authors: Sato Kazufumi , Kubota Toshihiko , Kawano Hirokazu
Published: May 2009

✓ A case of chronic diploic hematoma of the parietal bone is reported. This lesion is considered to have developed over several years following minor head trauma. Clinical, radiological, and pathological findings of this rare lesion are described. To the authors' knowledge, this is the first reported case of such an uncommon traumatic lesion with a description of its appearance on magnetic resonance imaging. Also discussed are the possible pathogenetic mechanisms involved in the slowly progressive enlargement of the lesion.
A new design of radiofrequency lesion electrodes for use in the caudalis nucleus DREZ operation
Authors: Nashold Blaine S. , El-Naggar Amr O. , Ovelmen-Levitt Janice , Abdul-Hak Muwaffak
Published: May 2009

✓ Two new right-angled electrodes have been designed for use at the dorsal root entry zone (DREZ) of the caudalis nucleus to provide relief of chronic facial pain. The electrode design was based on an anatomical study of the human caudalis nucleus at the cervicomedullary junction. Previously, caudalis nucleus DREZ operations were often followed by ipsilateral ataxia, usually in the arm. The new electrodes have significantly reduced this complication. A group of 21 patients with varied types of chronic facial pain have been treated, with pain relief in 70%.
Prediction of tolerance to carotid artery occlusion using transcranial Doppler ultrasound
Authors: Giller Cole A. , Mathews Dana , Walker Brandy , Purdy Philip , Roseland Angie M.
Published: May 2009

✓ Surgical sacrifice of the carotid artery is a frequently anticipated event during the treatment of certain aneurysms and tumors. The ability to predict tolerance to carotid artery occlusion is therefore of benefit when planning procedures in which the carotid artery is at risk. A trial of carotid artery occlusion using an angiographic balloon during concurrent neurological examination or blood flow studies is an accepted method for testing tolerance, but it carries the risks of an angiogram and cannot be performed at the bedside. Transcranial Doppler ultrasound (TCD) is a noninvasive modality that permits measurement of blood velocity in cerebral vessels. The immediate effects of carotid artery occlusion on middle cerebral artery (MCA) perfusion can be obtained by insonating this artery during manual carotid artery compression.

To compare the TCD response to carotid artery compression with the data obtained with more formal testing, the MCA of 22 patients was insonated during manual carotid artery compression and the results compared with the clinical tolerance to balloon occlusion in all patients and to blood flow studied by single photon emission computerized tomography before or during balloon occlusion in 14 of the 22 patients. Surgery was planned to treat giant unruptured aneurysms in 17 cases, intracranial tumors in three, a carotid-cavernous fistula in one, and a carotid artery injury in one. Fifteen patients showed a reduction in TCD flow velocities by no more than 65%; of these, 14 (93%) clinically tolerated the balloon occlusion test. Of the seven patients showing a TCD flow velocity decrease of more than 65%, six (86%) developed a transient focal deficit during the occlusion. It is concluded that the change in MCA velocity measured with TCD studies during manual carotid artery occlusion is a useful predictor of the clinical and blood flow responses to a trial of carotid artery occlusion with an angiographic balloon.
Treatment options and prognosis for multicentric juvenile pilocytic astrocytoma
Authors: Mamelak Adam N. , Prados Michael D. , Obana William G. , Cogen Philip H. , Edwards Michael S. B.
Published: May 2009

✓ Little is known about the risk of developing multicentric disease in patients with juvenile pilocytic astrocytoma (JPA), and even less about its prognosis. Only five cases have been reported. Between 1986 and 1992, the authors treated 90 patients with either primary or recurrent JPA, 11 of whom developed multicentric spread. Ten patients had primary tumors in the hypothalamic region, eight were under 4 years of age at initial diagnosis, all had initially undergone a subtotal resection or biopsy, and 10 received postoperative multiagent chemotherapy or irradiation for residual disease. Multicentric spread was discovered immediately to 108 months after initial diagnosis; nine patients were asymptomatic at the time. Most patients received chemotherapy for the multicentric disease, which was found throughout the craniospinal axis. During 21 to 148 months of follow-up monitoring, seven patients had stabilization or regression of multicentric disease and four died. Patients with hypothalamic region tumors were 23 times more likely to develop multicentric spread than were those with primary tumors located elsewhere (p < 0.001). Based on this review, it is concluded that multicentric spread of JPA occurs more frequently than was previously recognized. In patients with subtotally resected JPA and several years of follow-up review via magnetic resonance imaging, the incidence of recurrence in a site different from the original was 12%. Patients with subtotally resected JPA in the hypothalamic region should be considered to be at high risk for developing multicentric spread. Chemotherapy appears useful in stabilizing multicentric disease. Earlier detection and intervention may result in longer disease-free survival in patients with multicentric spread of JPA.
The far lateral/combined supra- and infratentorial approach
Authors: Baldwin Hillel Z. , Miller Christopher G. , van Loveren Harry R. , Keller Jeffrey T. , Daspit C. Phillip , Spetzler Robert F.
Published: May 2009

✓ A far lateral approach to the ventral brain stem, lower clivus, and anterior foramen magnum is described. Methods for further exposure of the superior petroclival region by incorporating a subtemporal craniotomy and posterior petrosectomy are also demonstrated. Eight sequentially illustrated steps depict this technique. The far lateral/combined supra- and infratentorial exposure is a comprehensive surgical approach that provides direct access to the entire anterior and lateral brain stem and craniovertebral junction. It minimizes brain-stem retraction and maximizes visualization of the neurovascular structures.
Production of matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 by human brain tumors
Authors: Nakagawa Takao , Kubota Toshihiko , Kabuto Masanori , Sato Kazufumi , Kawano Hirokazu , Hayakawa Taro , Okada Yasunori
Published: May 2009

✓ The role of matrix metalloproteinases (MMP's) and their inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1), in human brain tumor invasion was investigated. Gelatinolytic activity was assayed via gelatin zymography, and four MMP's (MMP-1, MMP-2, MMP-3, and MMP-9) and TIMP-1 were immunolocalized in human brain tumors and in normal brain tissues using monoclonal antibodies. The tissue was surgically removed from 44 patients: glioblastoma (five cases), anaplastic astrocytoma (six cases), astrocytoma (four cases), metastatic tumor (six cases), neurinoma (10 cases), meningioma (10 cases), and normal brain tissue (three cases). Glioblastomas, anaplastic astrocytomas, and metastatic tumors showed high gelatinolytic activity and positive immunostaining for MMP's; TIMP-1 was also expressed in these tumors, but some tumor cells were negative for the antibody. Astrocytomas had low gelatinolytic activity and the tumor cells showed no immunoreactivity for MMP's and TIMP-1. Although neurinomas and meningiomas had only moderate proteinase activity and exhibited positive immunoreactivity for MMP-9, intense expression of TIMP-1 was simultaneously observed in these tumor cells. These findings suggest that MMP's play an important role in human brain tumor invasion, probably due to an imbalance between the production of MMP's and TIMP-1 by the tumor cells.
Brachial plexus repair by peripheral nerve grafts directly into the spinal cord in rats
Authors: Bertelli Jayme Augusto , Mira Jean Claude
Published: May 2009

✓ Over the years, peripheral nerve grafts, a favorable environment for the support of axonal elongation, have attracted interest as a possible means of promoting spinal cord repair. In the experiments described here, rats underwent an avulsion injury of the brachial plexus, and the musculocutaneous nerve was repaired by direct insertion of peripheral nerve grafts into the spinal cord. After varying postoperative periods, the rats were submitted to a series of behavioral tests to evaluate forelimb and hindlimb function. They also underwent retrograde double-labeling studies. Nerve grafts were harvested and processed for electronic microscopy. The biceps muscle was removed and weighed and its histology studied.

After surgery, central axons effectively regenerated about 65 mm along the peripheral nerve grafts, restoring normal active elbow flexion. Forelimb movements were well coordinated in both voluntary and automatic activities. Clinical investigations showed that there were no side effects in the ipsilateral forepaw, contralateral forelimb, or either hindlimb. Regenerating axons stemmed from original motoneurons, foreign motoneurons, and even antagonist motoneurons, but this did not impair function. Ganglionic neurons from adjacent roots also sent processes to the peripheral nerve grafts.
Postoperative mutism in neurosurgery
Authors: Crutchfield J. Stuart , Sawaya Raymond , Meyers Christina A. , Moore Bartlett D.
Published: May 2009

✓ Mutism is defined as a state in which a patient is conscious but unwilling or unable to speak. It has been reported to occur in association with a multitude of conditions, including trauma, epilepsy, tumors, stroke, psychoses, and brain surgery. The cases of two patients who became mute in the immediate postoperative period are presented. The first patient developed mutism following removal of a parasagittal meningioma, and the second following removal of a posterior fossa medulloblastoma. It is believed that transient injury may have occurred to the supplementary motor cortex in the first case and to the dentate nuclei in the second case. It is interesting that these two areas are connected via pathways involving the ventrolateral nucleus of the thalamus, and that lesions of this thalamic nucleus can also lead to mutism. It therefore appears plausible that interruption of these pathways may be involved in the pathogenesis of mutism. Although mutism is an infrequent complication of brain surgery, neurosurgeons should be aware that it may occur following removal of lesions in these areas and that it is generally a transient condition.
Lhermitte-Duclos disease and Cowden's syndrome in an adolescent patient
Authors: Wells Gregg B. , Lasner Todd M. , Yousem David M. , Zager Eric L.
Published: May 2009

✓ Recent reports of seven cases of Lhermitte-Duclos disease occurring in adult patients with Cowden's syndrome (multiple hamartoma syndrome) strongly suggest that Lhermitte-Duclos disease is one of the types of neoplasia that characterize this syndrome. A case of Lhermitte-Duclos disease is reported in a 16-year-old girl with craniomegaly, choroidal hamartoma, and conjunctival papilloma of the right eye, and a history of bilateral multinodular adenomatous goiter and cystic hygroma. These findings strongly suggest a diagnosis of Cowden's syndrome. Although the syndrome traditionally has been defined by mucocutaneous criteria, it typically also involves hamartomas and neoplasia of internal organs, most commonly in the thyroid, breast, and female genitourinary tract. Because the mucocutaneous features may develop several decades after birth, the present case both supports the previously reported association between Lhermitte-Duclos disease and Cowden's syndrome and highlights the need for long-term follow-up monitoring of a pediatric patient with Lhermitte-Duclos disease because of the risk of malignancies associated with Cowden's syndrome.
High cervical pain and impairment of skull mobility as the only symptoms of an occipital condyle fracture
Authors: Stroobants Jan , Fidlers Luc , Storms Jean-Louis , Klaes Robert , Dua Guido , Van Hoye Marc
Published: May 2009

✓ Occipital condyle fractures are rarely reported in survivors of trauma. Most cases involve patients with a major head trauma, lower cranial nerve palsy, and/or suspected lesions demonstrated on plain x-ray films of the skull or cervical spine. The authors describe a traffic-accident victim in whom an atlanto-occipital joint lesion was suspected based only on mobility investigation of the skull. Axial high-resolution computerized tomography of the atlanto-occipital joint showed a fracture of the right occipital condyle.
Complications of CT-guided stereotactic biopsy of intra-axial brain lesions
Authors: Bernstein Mark , Parrent Andrew G.
Published: May 2009

✓ A series of 300 consecutive stereotactic biopsies for intra-axial brain lesions performed by one neurosurgeon was critically analyzed regarding complications of the procedure. Complications were incurred by a total of 19 patients (6.3%). Five patients (1.7%) died following the procedure, all due to intracranial hypertension: one from subarachnoid hemorrhage, one from intracerebral hemorrhage, and three from increased edema without hemorrhage. The three patients who died without hemorrhage all had marked intracranial hypertension at the time of biopsy. All five patients who died harbored a glioblastoma multiforme. The surviving 14 patients (4.7%) with complications suffered increased neurological deficit due to hemorrhage. In 10 (3.3%), the deficit was mild and/or transient; in the other four (1.3%), a major deficit was incurred which markedly affected the remainder of the patient's life. Therefore, mortality or major morbidity was seen in 3.0% of patients and minor morbidity in 3.3%. Stereotactic biopsy is a very effective procedure with a complication rate significantly lower than that of craniotomy (particularly in the population of patients selected for stereotactic biopsy), but in a small number of patients the outcome is devastating.
Surgical resection of third ventricle colloid cysts
Authors: Lewis Adam I. , Crone Kerry R. , Taha Jamal , van Loveren Harry R. , Yeh Hwa-Shain , Tew John M.
Published: May 2009

✓ It is still not determined which is the best surgical option for third ventricle colloid cysts. Since 1990, the authors have used a steerable fiberscope to remove colloid cysts in seven patients and have performed microsurgery via a transcallosal approach in eight patients. The two techniques were compared for operating time, length of hospital stay, incidence of complications, recurrence, and hydrocephalus, and days spent recuperating before return to work to determine if endoscopic removal of colloid cysts is a safe and effective alternative to microsurgery. Statistical analysis was adjusted for age, sex, and presenting symptoms.

Microsurgical cases averaged 206 minutes of operating time whereas endoscopic cases averaged 127 minutes (p = 0.01). For combined days spent in the intensive care unit and on the ward, the patients averaged 9.5 days after microsurgery and 4 days after endoscopy (p = 0.05). Postoperative complications occurred in five of eight patients after microsurgery and in one of seven patients after endoscopy (p = 0.09); complications were transient and primarily related to short-term memory loss. In all patients, preoperative symptoms resolved and the cysts have not recurred. Postoperatively, one patient required a ventriculoperitoneal shunt after microsurgery but all patients were shunt-independent after endoscopy. Patients returned to work an average of 59 days after discharge following microsurgery compared with an average of 26 days after endoscopy (p = 0.05). Compared with transcallosal microsurgery for the removal of colloid cysts, these preliminary results show that a steerable endoscope reduced operating time and that patients spent fewer days in the hospital and returned to work sooner after endoscopy.
Delayed postoperative tethering of the cervical spinal cord
Authors: Smith Kris A. , Rekate Harold L.
Published: May 2009

✓ Tethering of the spinal cord in the lumbar and sacral regions of children with congenital anomalies is a well-recognized problem; however, tethering in the cervical region has rarely been reported. A search of the literature revealed no reports of symptomatic postoperative cervical spinal cord tethering. The authors present five cases of delayed postoperative cervical spinal cord tethering and discuss the benefit of detethering in these patients. All five patients were young (16 to 42 years of age) at presentation. All had done well after an initial surgical procedure but returned between 1 and 31 years postoperatively with symptoms including severe headache, upper-extremity pain, and progressive neurological deficits. In each case, magnetic resonance imaging indicated dorsal tethering of the cord in the cervical region. Surgical exploration with microscopic sharp detethering of the cervical cord was performed on each patient with favorable results. To avoid retethering, wide Tutoplast duraplasty is recommended.
Intraoperative SEP monitoring in neurosurgery around the brain stem and cervical spinal cord: differential recording of subcortical components
Authors: Wagner Wolfgang , Peghini-Halbig Lydia , Mäurer Johannes C. , Perneczky Axel
Published: May 2009

✓ The results of intraoperative monitoring of median nerve somatosensory evoked potentials (SEP's) were evaluated in 75 neurosurgical patients in order to assess the role of differential derivation of brain stem (P14) and spinal cord (N13) wave activity. These components were compared with the conventionally recorded neck potential (“N13”) that reflects overlap of P14 and N13. The spinal cord N13 wave was recorded from the posterior to anterior lower aspect of the neck and the brain stem P14 wave from the midfrontal scalp to the nasopharynx; both derivations enabled isolated low-artifact recording of these components. In 18.7% of patients, moderate to major latency and/or amplitude shifts of N13 or P14 were found that were masked in conventional neck-scalp recordings of “N13”. There was a 6.7% false-negative rate in this series. Using a neck-scalp derivation alone, a 14.7% false-negative rate would have resulted and an isolated worsening of the P14 component (with stable neck potential) in six cases would have been overlooked. It is concluded that the proposed SEP recording technique allows independent assessment of spinal cord and brain stem activity. It is, therefore, superior to the conventional neck-scalp derivation technique, in which important information may be concealed or even lost due to the overlap of the brain stem P14 and spinal cord N13 potentials.
Extradural temporopolar approach to lesions of the upper basilar artery and infrachiasmatic region
Authors: Day J. Diaz , Giannotta Steven L. , Fukushima Takanori
Published: May 2009

✓ Surgical access to the parasellar, infrachiasmatic, and posterior clinoid regions has traditionally been accomplished through an intradural pterional or subtemporal approach. However, for large or complex lesions in these locations, such traditional trajectories may not afford sufficient exposure for complete obliteration of the pathological process. The authors describe an anterolateral transcavernous approach to this region that includes the following components: 1) extradural removal of the sphenoid wing and exposure of the superior orbital fissure and foramen rotundum; 2) removal of the anterior clinoid process via the anterolateral route; 3) decompression of the optic canal; 4) extradural retraction of the temporal tip; 5) transcavernous mobilization of the carotid artery and third cranial nerve; and 6) removal of the posterior clinoid process. This method results in enhanced exposure with minimal brain retraction and preservation of the temporal tip bridging veins.

This approach has been used in 22 patients: 10 with basilar top aneurysms, eight with craniopharyngiomas, one with a tuberculum sellae meningioma, and two with trigeminal neuromas; the last patient had a carotidcavernous fistula and a concomitant pituitary adenoma. Complete clip ligation was performed for all 10 basilar artery aneurysms, and gross total resection was achieved with preservation of the pituitary stalk in all tumor cases. Microscopic total resection was not possible in two cases of craniopharyngioma due to hypothalamic invasion. Two patients suffered transient postoperative hemiparesis, and one patient has persisting weakness; however, no patient followed for more than 6 months suffered any persistent cranial nerve morbidity. It is concluded that this procedure can serve as an alternative to either the transsylvian or subtemporal approaches when cranial base pathologies are large or complex.
Outcome of aggressive removal of cavernous sinus meningiomas
Authors: DeMonte Franco , Smith Harold K. , Al-Mefty Ossama
Published: May 2009

✓ Despite recent advances in surgery of the cavernous sinus, meningiomas in that area offer a formidable challenge. The rationale for aggressive surgical removal of cavernous sinus meningiomas is based on the presumption that the extent of removal is inversely related to the rate of recurrence. Over the past 10 years, 41 patients with histologically benign meningiomas involving the cavernous sinus underwent aggressive surgery. Total removal, as confirmed by intraoperative inspection and postoperative radiological studies, was achieved in 31 patients (76%). Twelve patients have been followed for more than 5 years; 10 underwent total tumor removal and only one of these experienced recurrence (5 years after surgery). The other two patients underwent subtotal removal and had symptomatic and radiological evidence of regrowth 3 and 4 years after surgery. Pre-existing cranial nerve deficits improved in only 14% of the patients, remained unchanged in 80%, and worsened permanently in 6%. Seven patients experienced a total of 10 new cranial nerve deficits, four of which involved the nerves subserving ocular motor function. Extraocular muscle function did not worsen in the 25 patients with a seeing eye ipsilateral to the tumor, and no instance of visual worsening occurred.

Two patients died 4 months after surgery, one from severe delayed vasospasm and hypothalamic infarction and the other because of a myocardial infarction. Another patient died from a pulmonary embolus on the 9th postoperative day. There were three instances of cerebral ischemia; one was transient, lasting less than 24 hours, while two were related to injury of the middle cerebral artery and resulted in residual hemiplegia. Other complications included three cases of nonfatal pulmonary emboli, two cerebrospinal fluid leaks, and one instance each of exposure keratitis, acute hypothyroidism, and cerebral edema.
Infiltration of the carotid artery by cavernous sinus meningioma
Authors: Kotapka Mark J. , Kalia Kamal K. , Martinez A. Julio , Sekhar Laligam N.
Published: May 2009

✓ Intracranial meningiomas are known to infiltrate surrounding structures such as the calvaria and dural sinuses, and the brain itself. The issue of whether meningiomas invade major intracranial arteries is of clinical importance, particularly in the case of meningiomas of the cavernous sinus. If a meningioma has not invaded the carotid artery wall, complete tumor removal may be accomplished with careful dissection from the carotid artery; however, if the tumor has infiltrated the wall of the carotid artery, complete removal may require sacrifice of the artery.

To determine whether cavernous sinus meningiomas invade the carotid artery, the authors retrospectively reviewed the histopathology of 19 consecutively treated individuals whose carotid artery was sacrificed during removal of a meningioma involving the cavernous sinus. Patients were selected for carotid artery resection based on preoperative magnetic resonance imaging studies demonstrating complete encasement of the artery. Reconstruction of the carotid artery was planned depending on the results of preoperative balloon test occlusion with blood flow determinations.

None of the 19 patients had pathological evidence of malignant tumor. Eight individuals (42%) were found to have infiltration of the carotid artery by meningioma. In five cases, focal involvement of the adventitia of the carotid artery wall was noted and, in three, the vessel was infiltrated up to the tunica muscularis. In no case was the tunica muscularis invaded by tumor. Thus, meningiomas of the cavernous sinus do infiltrate the internal carotid artery and, in order to completely resect these lesions and effect a surgical cure, it may be necessary to sacrifice the carotid artery with or without reconstruction.
Sialorrhea from fourth ventricle hydrocephalus
Authors: Filippi Stefania , Monaco Pierfrancesco , Godano Umberto , Calbucci Fabio
Published: May 2009

✓ The case of a 50-year-old man with tetraventricular hypertensive hydrocephalus is presented, remarkable for fourth ventricle dilatation. This patient showed a significant sialorrhea as the main symptom, which is quite unusual. This condition was successfully treated by cerebrospinal fluid diversion. The uncommon features of this case are summarized.
Sacral fixation using iliac instrumentation and a variable-angle screw device
Authors: Baldwin Nevan G. , Benzel Edward C.
Published: May 2009

✓ Secure fixation of the sacrum is technically challenging. The bone of the dorsal sacral surface is often thin, making hook fixation tenuous. The use of bone screws in the sacral pedicles has gained popularity, but rigidity is often not achieved and screw pullout is common. Solid constructs have been achieved using angled rods to stabilize the ilium, but these methods are technically difficult and time-consuming to perform.

A technique is described that achieves rigid sacral fixation by adding a bone screw placed through both cortical surfaces of the ilium. This bone screw is a new type that allows attachment to a rod at variable angles. It permits easy attachment to an appropriately contoured rod, which is affixed to sacral hooks or screws. The resulting configuration of the bone-metal interface creates a tripod for load distribution. Additionally, the splayed geometry of these purchase sites provides a significant biomechanical advantage preventing the instrument from being pulled out. The technique for this fixation method, particularly for patients with complex spinal disorders, is described. Use of this new technique provides significant advantages to the spine surgeon in situations in which substantial sacral fixation integrity is necessary.