bluuebunny/crossref_metadata_2025 huggingface dataset:
Meningiomas arising from the falcotentorial junction
Authors: Asari Shoji , Maeshiro Tomohide , Tomita Susumu , Kawauchi Masamitsu , Yabuno Nobuyoshi , Kinugasa Kazushi , Ohmoto Takashi
Published: June 2009

✓ Meningiomas arising from the falcotentorial junction are extremely rare. The authors describe the clinical features, neuroimaging studies, and results of surgical treatment of meningiomas of the falcotentorial junction and clarify the characteristics of this lesion based on a review of the literature and seven patients treated at their institution. The most common symptoms resulted from intracranial hypertension. Upward-gaze palsy appeared in only one patient. Computerized tomography (CT) showed no specific findings, but there was no evidence of edema around the tumor. Magnetic resonance (MR) imaging revealed a round, smooth-bordered mass with a peritumoral rim, without edema, and showing marked contrast enhancement. The multiplanar capability of MR imaging delineated the relationship between the tumor and adjacent structures better than did CT. Detailed knowledge of the vascular structures, especially evidence of occlusion of the galenic venous system and the development of collateral venous channels, is critical for successful surgery; stereoscopic cerebral angiography is necessary to achieve this aim.

The seven patients described developed five types of collateral venous channels: through the basal vein of Rosenthal to the petrosal vein, through the veins on the medial surface of the parietal and occipital lobes to the superior sagittal sinus, through superficial anastomotic veins, through veins of the posterior fossa to the transverse or straight sinus, and through the falcian veins to the superior sagittal sinus. The first three types mainly developed after occlusion of the galenic system. The tumors were removed through the occipital transtentorial approach with a large window at the posterior part of the falx. A favorable prognosis for patients undergoing surgical treatment of falcotentorial junction meningiomas can be expected if detailed neuroimaging studies and microsurgical techniques are used.
An observational study of near-infrared spectroscopy during carotid endarterectomy
Authors: Kirkpatrick Peter J. , Smielewski Pietr , Whitfield Peter C. , Czosnyka Marik , Menon David , Pickard John D.
Published: June 2009

✓ Near-infrared spectroscopy was used to monitor changes in the cerebral oxygenation state in 13 patients during carotid endarterectomy. Variations in the levels of the chromophores (oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (Hb), and oxidized cytochrome (CytO2)), and the total hemoglobin content (tHb) were compared with changes in middle cerebral artery flow velocity measured using transcranial Doppler ultrasonography. Of eight patients who showed a fall in flow velocity on application of the internal carotid artery cross-clamp, seven demonstrated a rapid and closely correlated fall in HbO2 signal, and an increase in Hb. Levels of CytO2 and tHb remained unchanged. During endarterectomy, recovery of the HbO2 and Hb levels toward preclamp baseline values occurred in three of these patients. Intraoperative shunts accelerated recovery of HbO2 and Hb signals in two of three individuals. Release of the internal carotid cross-clamp resulted in a rapid increase in HbO2 and decrease in Hb signal in those patients in whom spontaneous recovery had not occurred; in five instances, a hyperemia evolved with raised flow velocity and HbO2 to above baseline values. Cross-clamping and subsequent reperfusion of the external carotid artery had no effect on any parameter measured. The authors conclude that near-infrared spectroscopy can register changes in cerebral oxygenation during carotid endarterectomy without significant contamination from extracranial tissues.
Endoscopic treatment of loculated hydrocephalus
Authors: Lewis Adam I. , Keiper Glenn L. , Crone Kerry R.
Published: June 2009

✓ Loculated hydrocephalus remains a difficult neurosurgical problem and endoscopes designed to navigate through the ventricular system provide a new option for treatment. The authors review their experience, during the period March 1990 to June 1993, using a steerable fiberscope in 34 cases of loculated hydrocephalus to evaluate the efficacy of endoscopic cyst fenestration. The goals of treatment were to control hydrocephalus, simplify preexisting shunt systems, and reduce operative morbidity. Endoscopic cyst fenestrations reduced the shunt revision rate from 3.04 per year prior to endoscopy to 0.25 per year after the procedure, during a follow-up period ranging from 8 to 45 months, mean 26 months. However, eight patients (23.5%) required 14 repeat operations to control loculated hydrocephalus. After endoscopy, patients with multiloculated hydrocephalus had a nearly fivefold increased risk (relative risk 4.85) for shunt malfunction and more than a twofold increased risk (relative risk 2.43) for cyst recurrence versus patients with uniloculated hydrocephalus. Similarly, six (50%) of 12 patients shunted prior to endoscopy required a repeat endoscopic procedure (relative risk 5.56). Although repeat endoscopic procedures may be required to control hydrocephalus, endoscopic cyst fenestration avoided placement of a shunt in seven (33%) of 21 patients with uniloculated hydrocephalus. One patient, encountered early in the authors' experience, required a craniotomy for fenestration of multiple ventricular cysts. Endoscopic complications included cerebrospinal fluid leakage in one case and ventriculitis in another. The authors conclude that endoscopic treatment of loculated hydrocephalus is a safe, minimally invasive technique that should be considered as the initial treatment option.
The poor prognosis of ruptured intracranial aneurysms of the posterior circulation
Authors: Schievink Wouter I. , Wijdicks Eelco F. M. , Piepgras David G. , Chu Chu-Pin , O'Fallon W. Michael , Whisnant Jack P.
Published: June 2009

✓ The first 48 hours after aneurysmal subarachnoid hemorrhage are critical in determining final outcome. However, most patients who die during this initial period are not included in hospital-based studies. We investigated the occurrence of subarachnoid hemorrhage in a population-based study to evaluate possible predictors of poor outcome. All patients diagnosed with aneurysmal subarachnoid hemorrhage between 1955 and 1984 were selected for analysis of mortality in the first 30 days using the medical record—linkage system employed for epidemiological studies in Rochester, Minnesota. One hundred and thirty-six patients were identified. The mean age of these 99 women and 37 men was 55 years. Rates for survival to 48 hours were 32% for the 19 patients with posterior circulation aneurysms, 77% for the 87 patients with anterior circulation aneurysms, and 70% for the 30 patients with a presumed aneurysm (p < 0.0001). Rates for survival to 30 days were 11%, 57%, and 53%, respectively, in these three patient groups (p < 0.0001). Clinical grade on admission to the hospital, the main variable predictive of death within 48 hours, was significantly worse in patients with posterior circulation aneurysms than in others (p < 0.0001).

The prognosis of ruptured posterior circulation aneurysms is poor. The high early mortality explains why posterior circulation aneurysms are uncommon in most clinical series of patients with subarachnoid hemorrhage. The management of incidentally discovered intact posterior circulation aneurysms may be influenced by these findings.
Effects of ethanol on respiratory function in traumatic brain injury
Authors: Zink Brian J. , Feustel Paul J.
Published: June 2009

✓ It has been observed that traumatic brain injury (TBI) increases the susceptibility of the brain to subsequent hypoxia, and prolonged apnea occurs in ethanol (EtOH)-treated animals following brain injury. This investigation tests the hypothesis that EtOH suppresses ventilation and hypercapnic respiratory drive following TBI. Immature pigs were anesthetized with halothane and received a 2 to 3 atm fluid-percussion brain injury. Respiratory parameters, including tidal volume, frequency, ventilation (E), and arterial blood gases were measured on 100% O2 and on 5% to 6% inspired CO2 in O2 prior to and at 10, 60, 120, and 180 minutes after TBI. Hypercapnic response sensitivity (S) was measured as the change in E per mm Hg increase in PaCO2. Intracranial pressure, mean arterial blood pressure, heart rate, brain temperature, glucose, and EtOH levels were also monitored. Three groups were studied: the first group of six received EtOH (3.5 gm/kg, intragastrically) without brain injury; the second group of six received TBI without EtOH; the third group of eight received EtOH and TBI. Ethanol levels were 121 ± 13 (standard error of the mean) mg/dl in the EtOH/TBI group (136 ± 25 in the EtOH group) at the time of injury, and 175 ± 12 mg/dl in the EtOH/TBI group (200 ± 20 mg/dl in the EtOH group) at 120 minutes after injury. The EtOH/TBI animals had significantly lower E and S, and higher PaCO2 following brain injury (p < 0.05, repeated-measures analysis of variance). No significant differences were identified between groups for pH, PaCO2, intracranial pressure, heart rate, brain temperature, or glucose levels. Ethanol intoxication leads to significant impairment of respiratory control following traumatic brain injury and may contribute to brain injury in intoxicated trauma victims.
The role of the epidermal growth factor receptor in human gliomas: I. The control of cell growth
Authors: U Hoi Sang , Espiritu Olivia D. , Kelley Patricia Y. , Klauber Melville R. , Hatton James D.
Published: June 2009

✓ The epidermal growth factor receptor (EGFR) gene is amplified in over 40% of primary human glioblastomas and overexpressed in the majority. The authors' investigations demonstrate that the function of the EGFR in glioblastomas is distinct from that in other human cancers because it does not appear to mediate the primary growth-promoting effect of EGF. Findings show that the level of EGFR expression does not directly predict the growth response to EGF, with growth stimulated in some cells but inhibited in others when cells were cultured in plastic dishes. On the other hand, when human glioblastoma cells were placed in soft agar cultures, the cell line expressing the highest levels of the EGFR demonstrated considerable colony formation in response to EGF treatment. In addition, cell lines with the highest EGFR levels were also more resistant to the growth-suppressive effects of retinoic acid when maintained in soft agar. These observations suggest that even though the overexpression of the EGFR did not confer a distinct growth advantage to glioma cells cultured on flat culture dishes, the ability of these cells to maintain anchorage-independent growth in soft agar especially in response to EGF and retinoic acid is facilitated. Because anchorage-independent growth is the bestin vitrocorrelate to tumorigenicity, amplification and overexpression of the EGFR in human glioblastoma cells may be in part responsible for the tumorigenic potential of these cells.
The role of epidermal growth factor receptor in human gliomas: II. The control of glial process extension and the expression of glial fibrillary acidic protein
Authors: U Hoi Sang , Espiritu Olivia D. , Kelley Patricia Y. , Klauber Melville R. , Hatton James D.
Published: June 2009

✓ Our earlier investigations of the biology of the epidermal growth factor receptor (EGFR) in human gliomas demonstrated that the level of EGFR expression did not directly predict the glioma growth response to EGF, suggesting that the function of the EGFR in glioblastomas might not be limited to mediating the growth effects of EGF. We conducted the current studies to investigate the function(s) of the EGFR not related to growth control in human gliomas. These investigations show that the EGFR mediates the stimulative effects of EGF on glial process extension and glial fibrillary acidic protein (GFAP) expression. In addition, the level of EGFR expression correlates inversely with glioma cell responsiveness to differentiation promoting agents (for example, nerve growth factor and transforming growth factor-β) that act through transmembrane tyrosine kinase receptors. Thus, glioma lines with a high level of EGFR expression (for example, T-98G cells) responded to fewer differentiation promoting factors than lines with a low level of EGFR expression (such as U-373MG cells). Our results suggest that the EGFR in gliomas may participate in mediating the process extension and GFAP stimulative effects of both EGF and other differentiation promoting agents. These properties represent components of the differentiated state in glia because their expression is stimulated by dibutyryl cyclic adenosine monophosphate in normal astrocytes. The involvement of the EGFR in the expression of these glial specific properties suggests that the EGFR may play an important role in glial differentiation.
Alternative RNA splicing of the hyaluronic acid receptor CD44 in the normal human brain and in brain tumors
Authors: Nagasaka Susumu , Tanabe Kenneth K. , Bruner Janet M. , Saya Hideyuki , Sawaya Raymond E. , Morrison Richard S.
Published: June 2009

✓ The cell-surface receptor for hyaluronic acid, CD44, is expressed by both normal and malignant cells. Numerous CD44 isoforms have recently been identified that are derived by alternative ribonucleic acid splicing. The expression of some CD44 isoforms has been shown to be involved in tumor progression and metastatic spread in a rat carcinoma model and in human carcinomas. In the present study, CD44 isoform expression was evaluated by reverse transcriptase—polymerase chain reaction (PCR) analysis in frozen sections derived from three samples of normal brain tissue and from 40 brain tumors, including samples of glioblastoma multiforme, anaplastic astrocytoma, low-grade astrocytoma, cerebral primitive neuroectodermal tumor, medulloblastoma, metastatic colon carcinoma, and metastatic melanoma. Normal brain tissue adjacent to the tumors was also examined in 14 of 18 glioblastomas. In all normal brain and tumor samples, with the exception of metastases from colon carcinoma, PCR analysis demonstrated one prominent product that corresponded to the CD44H hematopoietic form of CD44. Metastases from colon carcinoma demonstrated two prominent PCR amplification products corresponding to CD44H and CD44R1. These results suggest that CD44H is the predominant isoform of this protein in normal human brain tissue and in human neuroectodermal tumors of varying degrees of malignancy. The ability of CD44H to mediate tumor cell motility and invasiveness (in contrast to CD44R1) suggests that the CD44 alternative splicing pattern of neuroectoderm-derived tumors may enhance their local biological aggressiveness and intracerebral spread. The lack of expression of larger molecular weight CD44 variants by primary brain tumors may also partially explain why these tumors rarely metastasize to distant sites.
Microsurgical anatomy around the foramen of Luschka in relation to intraoperative recording of auditory evoked potentials from the cochlear nuclei
Authors: Kuroki Akira , Møller Aage R.
Published: June 2009

✓ Three cadaveric heads were dissected to investigate the microsurgical anatomy around the foramen of Luschka. It was found possible to place a recording electrode in proximity to the cochlear nuclei by inserting it in the lateral recess of the fourth ventricle through the foramen of Luschka. In operations of the cerebellopontine angle using the retromastoid approach, access to the foramen of Luschka and the lateral recess is obtained by retracting the biventral lobule of the cerebellum in a caudal—rostral direction under a caudal—rostral/medial field of vision. The craniectomy might need to be enlarged a few millimeters in the caudal direction. A wick electrode can be inserted in the lateral recess beneath the choroid plexus in a rostromedial direction and to a depth of approximately 3 to 5 mm from the foramen of Luschka without excessive retraction of the cerebellum. The optimum position for the recording electrode is in the triangle formed by the axis of the cochlear nerve and the glossopharyngeal nerve and by the lip of the foramen of Luschka. The caudal retromastoid approach is more suitable than the translabyrinthine technique for recording from the cochlear nuclei as well as for implantation of stimulating electrodes into the cochlear nuclei for use as hearing prostheses.
Focal ischemia due to traumatic contusions documented by stable xenon-CT and ultrastructural studies
Authors: Schröder Marc L. , Muizelaar J. Paul , Bullock M. Ross , Salvant Jackson B. , Povlishock John T.
Published: June 2009

✓ A traumatic cerebral contusion causes a zone of perifocal neuronal necrosis, the cause of which is not known; the surgical management of these lesions remains controversial. To determine the pathophysiological mechanisms responsible for brain damage after contusions, the authors performed cerebral blood flow (CBF) mapping studies and related these to change in local cerebral blood volume (CBV) and ultrastructure. In 11 severely head injured patients with contusion, CBF and CBV were measured in pericontusional areas using stable xenon-computerized tomography (CT). These studies demonstrated a profound reduction in perilesional CBF (mean 17.5 ± 4 ml/100 g/min), which was always accompanied by a zone of edema defined by CT density measurements. Mean CBV in these regions was 2.3 ± 0.4 ml/100 g, a reduction to approximately one-half the value of 4.8 ml/100 g found in the nonedematous regions, and to approximately 35% of the value of 6.0 ml/100 g found in normal volunteers. Ultrastructural analysis of the pericontusional tissue, taken at surgery in four patients with high intracranial pressure showed glial swelling with narrowing of the microvascular lumina due to massive podocytic process swelling. Additionally, some suggestion of vascular occlusion due to erythrocyte and leukocyte stasis was seen. These data support the conclusion that microvascular compromise by compression and/or occlusion is a major event associated with profound perilesional hypoperfusion, which is a uniform finding within edematous pericontusional tissue.
Quadrant anatomy of the articular pillars (lateral cervical mass) of the cervical spine
Authors: Pait T. Glenn , McAllister Phillip V. , Kaufman Howard H.
Published: June 2009

✓ Knowledge of the relevant anatomy is important when developing a strategy for introducing screws into the lateral masses to secure internal fixation devices. This paper defines key bony landmarks and their relationship to critical neurovascular structures and identifies a location for safe placement of cervical articular pillar (lateral mass) screws.

Measurements of anatomical landmarks in 10 spines from human cadavers aged 61 to 85 years were made by caliper and a metric ruler. Landmarks were the lateral facet line, rostrocaudal line, medial facet line, intrafacet line, and medial facet line—vertebral artery line. The average distances and ranges were recorded. Such great variance existed in measurements from spine to spine and within the same spine as to render averages clinically unreliable. Dissection revealed that division of the articular pillar into four quadrants leaves one, the superior lateral quadrant, under which there are no neurovascular structures; this may be considered the “safe quadrant” for placement of posterior screws and plates.
In vivo inhibition of angiogenesis and growth of the human U-87 malignant glial tumor by treatment with an antibody against basic fibroblast growth factor
Authors: Stan Alexandru C. , Nemati Mohammad N. , Pietsch Torsten , Walter Gerhard F. , Dietz Hermann
Published: June 2009

✓ The effectiveness of in vivo suppression of neovascularization and growth of malignant glial tumors by in situ administration of an antibody directed against basic fibroblast growth factor (bFGF), a strong mitogen for cells of mesodermal origin, was tested. One hundred fifty congenitally athymic nude rats (Han rnu/rnu) were implanted intracerebrally with U-87MG tumor cells, known constitutive producers of bFGF. The animals were randomly assigned to six groups of 25 animals each. Animals were treated by in situ application of saline (Group F), control antibody (Group D), or polyclonal antibFGF antibody (Group B). In additional groups a putative effect on tumor growth caused by the treatment application device itself (between growth control Groups A and E), and the effect of heat-inactivated tumor cells (negative control Group C) were tested. After 3 weeks of treatment, tumor progression and degree of neovascularization were morphometrically recorded. In the untreated Groups A and E massive tumor growth was recorded, consisting of 19.9% ± 0.4% and 27.1% ± 0.5%, respectively, of the total brain cross-sectional area. In Group C, no tumor growth occurred. In control Groups D and F tumor progression consisted of 18.6% ± 0.4% and 18.5% ± 0.4%, respectively, of the total brain crosssectional area; whereas in the anti-bFGF treated Group B, significantly smaller tumor masses measuring 7.2% ± 0.1% were recorded. New blood vessels were located both peritumorally and intratumorally and defined as numerical density and area fraction (number/area and area/area). Significantly more new blood vessels were found in Groups A, D, E, and F, ranging from 41,380/mm2 ± 464/mm2 to 53,442/mm2 ± 150/mm2 peritumorally and 51,846/mm2 ± 495/mm2 to 64,660/mm2 ± 183/mm2 intratumorally than in the anti-bFGF treated Group B, which numbered 8220/mm2 ± 225/mm2 peritumorally and 16,554/mm2 ± 236/mm2 intratumorally. The authors conclude that treatment with anti-bFGF antibody is effective in inhibiting tumor-induced angiogenesis and correlated tumor progression. However, owing to the character of the experimental system used, one cannot exclude the possibility that application of the specific anti-bFGF antibody also counteracts device-induced neovascularization. The authors suggest that combined surgical excision and adjuvant immunotherapy of tumors such as glioblastoma and other malignant brain tumors that express bFGF might prevent tumor recurrence.
Middle cranial fossa arachnoid cyst developing in infancy
Authors: Okumura Yoshinari , Sakaki Toshisuke , Hirabayashi Hidehiro
Published: June 2009

✓ The pathophysiology of primary arachnoid cysts of the middle cranial fossa is still unclear, and no widely accepted therapeutic criteria for this condition have been established. The authors present the case of a 7-year-old boy with this cyst accompanied by temporal lobe hypoplasia. On the basis of computerized tomography taken on the 2nd day after birth and magnetic resonance imaging upon admission, the arachnoid cyst in this case was attributed to brain hypoplasia secondary to abnormal arachnoid development and was confirmed to have developed primarily during infancy. Experience with this case yielded new findings useful in clarifying the pathophysiology of this condition and establishing therapeutic criteria for such a case.
Ossification of the anterior longitudinal ligament and Forestier's disease: an analysis of seven cases
Authors: McCafferty Randall R. , Harrison Michael J. , Tamas Laszlo B. , Larkins Mark V.
Published: June 2009

✓ A retrospective review was conducted on the records and radiographs of six symptomatic patients and one asymptomatic patient with Forestier's disease. No other series of patients with this disease is found in the neurosurgical literature. Forestier's disease, also known as diffuse idiopathic skeletal hyperostosis (DISH), is an idiopathic rheumatological abnormality in which exuberant ossification occurs along ligaments throughout the body, but most notably the anterior longitudinal ligament of the spine. It affects older men predominantly; all of our patients were men older than 60 years of age. The disease is usually asymptomatic; however, dyspnea, dysphagia, spinal cord compression, and peripheral nerve entrapment have all been documented in association with the disorder. Five of the six symptomatic patients presented with dysphagia due to esophageal compression by calcified anterior longitudinal ligaments, and one patient developed recurrent spinal stenosis when scar tissue from a previous decompressive laminectomy became calcified. All patients responded well to surgery. Two of the four patients who underwent removal of cervical osteophytes required several months following surgery for the dysphagia to resolve. This would support the hypothesis that not all cases of dysphagia in Forestier's disease are due to mechanical compression. Dysphagia may result from inflammatory changes that accompany fibrosis in the wall of the esophagus or from esophageal denervation. Evaluation of dysphagia even in the presence of Forestier's disease must rule out occult malignancy. The authors' experience suggests that dysphagia in the setting of Forestier's disease is an underrecognized entity amenable to surgical intervention.
Relationship of intraoperative electrophysiological criteria to outcome after selective functional posterior rhizotomy
Authors: Steinbok Paul , Gustavsson Bengt , Kestle John R. W. , Reiner Ann , Cochrane D. Doug
Published: June 2009

✓ At British Columbia's Children's Hospital, the criteria used in selective functional posterior rhizotomy (SFPR) evolved in three distinct phases. In Phase 1 the electrophysiological criteria for abnormality included a low threshold to a single stimulation, a sustained response to 50-Hz stimulation, and spread outside the segmental level being stimulated. In Phase 2 the electrophysiological criteria were unchanged, but fewer L3–4 nerve roots were cut. In Phase 3, fewer L3–4 nerve roots were cut, as in Phase 2, but based on the results of posterior nerve root stimulation in nonspastic controls, the only electrophysiological criterion used was contralateral and suprasegmental spread. The present study examined the relationship between the criteria used in each phase and patient outcome.

The records of 77 consecutive children who underwent SFPR and had a minium follow-up period of 1 year were reviewed, comprising 25, 19, and 33 patients in Phases 1, 2, and 3, respectively. Outcome parameters included quantitative assessments of lower-limb spasticity and range of motion, and qualitative assessments of lower-limb function.

In Phase 3, 52% of the nerve roots were cut, compared to 66% in Phases 1 and 2. In all three phases there was a significant decrease in lower-limb spasticity and an increase in range of movement, with the smallest decrease in spasticity in Phase 3. Over 90% of children in each phase improved with respect to lower-limb function, and excluding independent walkers and quadriplegics confined to a wheelchair, improvement in the level of ambulation occurred in 87.5%, 71.4%, and 73.7% of patients, in Phases 1, 2, and 3, respectively.
Low-grade astrocytoma with neuraxis dissemination at diagnosis
Authors: Gajjar Amar , Bhargava Ravi , Jenkins Jesse J. , Heideman Richard , Sanford Robert A. , Langston James W. , Walter Andrew W. , Kuttesch John F. , Muhlbauer Michael , Kun Larry E.
Published: June 2009

✓ Little is known about low-grade astrocytoma with neuraxis dissemination at diagnosis. A review of medical records identified this phenomenon in eight of 150 pediatric patients evaluated between 1985 and 1994 for histologically confirmed low-grade astrocytoma. These patients (five male and three female) ranged in age from 5 months to 20 years (median 8 years). Symptoms of neuraxis disease were minimal or absent. Primary tumor sites were the hypothalamus in four cases, brainstem/spinal cord in three, and temporal lobe in one. Patterns of dissemination (evaluated by computerized tomography and/or magnetic resonance imaging techniques) appeared to be related to the primary site: hypothalamic tumors metastasized along the ventricular cerebrospinal fluid pathways, and tumors in other locations disseminated along subarachnoid pathways. Following initial treatment with chemotherapy (in three), partial resection (in one), radiation therapy (in three), and chemotherapy plus irradiation (in one), four patients required salvage therapy for progressive or recurrent disease. Seven of the eight patients are alive with stable or progressive disease 6 to 105 months postdiagnosis (median 15 months). Low-grade astrocytoma with initial neuraxis dissemination is responsive to chemotherapy and radiation, a proportion showing periods of stable disease. The optimum therapy or combination of therapies remains unclear.
Aneurysm of a persistent primitive olfactory artery
Authors: Tsuji Takehisa , Abe Masamitsu , Tabuchi Kazuo
Published: June 2009

✓ A ruptured anterior cerebral artery (ACA) aneurysm is reported in a patient in whom an anomalous ACA arose from the internal carotid artery at the bifurcation. The aberrant artery coursed anteriorly along the ipsilateral olfactory tract and made a hairpin turn posterior to the olfactory bulb, supplying the circulation of the ACA. Persistence of the primitive olfactory artery is suggested as an embryological origin of this vascular anomaly.
Lesionectomy versus electrophysiologically guided resection for temporal lobe tumors manifesting with complex partial seizures
Authors: Jooma Rashid , Yeh Hwa-shain , Privitera Michael D. , Gartner Maureen
Published: June 2009

✓ Complex partial seizures associated with tumors and other mass lesions are readily diagnosed by modern imaging techniques but their optimum surgical treatment remains unresolved. Lesionectomy has been reported to produce seizure outcomes equal to outcomes after resection that ablates the epileptogenic cortex with the lesion. However, some evidence suggests that when the lesion is in the temporal lobe, simple excision of the tumor or lesion more often fails to control seizures. After retrospectively reviewing the records of 30 patients with complex partial seizures and temporal lobe tumors who underwent surgical treatment at the University of Cincinnati hospitals (1985–1992), the authors divided them into two groups: Group A (16 patients) underwent lesionectomy only and Group B (14 patients) received surgical treatment for seizures with electroencephalographic delineation of the epileptogenic zone and resection of the lesion. Seizure control was best achieved in Group B patients with 13 (92.8%) seizure free at follow up (mean 52 months). Only three (18.8%) of the Group A patients became seizure free after lesionectomy at follow up (mean 33 months). In eight Group A patients, who underwent temporal lobectomy as a second procedure after lesionectomy failed to control seizures, five (62.5%) became seizure free. Group B patients had a longer duration of seizures and were more likely to have lesions smaller than 2.5 cm compared with Group A. Analysis of covariance demonstrated that the differences in outcome between the groups remained significant even with adjustment for the variation in duration of seizures (p = 0.0006) and size of tumor (p = 0.0001). Based on this study, the authors found that the probable relief from seizures caused by a temporal lobe lesion is greater if the region of epileptogenicity, usually the amygdalohippocampal complex, is resected along with the tumor in a temporal lobectomy.
Use of fluorescence in situ hybridization to detect loss of chromosome 10 in astrocytomas
Authors: Dalrymple Stephen J. , Herath John F. , Ritland Steven R. , Moertel Cheryl A. , Jenkins Robert B.
Published: June 2009

✓ Models describing progression in the genetic derangement of glial tumors have shown loss of chromosome 10 to occur most frequently in high-grade lesions, suggesting that identification of this loss may be prognostically significant. Fluorescence in situ hybridization (FISH) analysis may be a valuable adjunct to histological grading if it can accurately detect this loss. In this paper the authors correlate results obtained from FISH, cytogenetic, molecular genetic, and flow cytometric analyses of a series of 39 brain specimens, including seven normal, two gliotic, and 30 neoplastic (one Grade II, one Grade III, and 28 Grade IV astrocytoma) specimens.

Contiguous section of freshly resected surgical tissue were submitted for tissue culturing (karyotype) and touch preparation (FISH), snap-frozen (molecular genetic), or paraffin-embedded (histology and flow cytometry). Centromere-specific probes for chromosomes 10 and 12 were used for FISH analysis, and 19 restriction fragment length polymorphisms (two p-arm and 17 q-arm) and four microsatellite sequence polymorphisms (three p-arm and one q-arm) were used for molecular genetic analysis of chromosome 10. Findings showed FISH and loss of heterozygosity (LOH) analyses to be concordant in 33 of 38 specimens (sensitivity 94%, specificity 81%), with one specimen indeterminate on LOH analysis. Both FISH and LOH analyses were more sensitive at detecting chromosome 10 loss than conventional cytogenetic (karyotype) analysis. The authors conclude that FISH is a sensitive test for detecting chromosome 10 loss and ploidy in astrocytic tumors.
Biomechanical analysis of bone mineral density, insertion technique, screw torque, and holding strength of anterior cervical plate screws
Authors: Ryken Timothy C. , Clausen John D. , Traynelis Vincent C. , Goel Vijay K.
Published: June 2009

✓ The bone mineral density (BMD) of 99 cadaveric cervical vertebral bodies (C3–7) was determined using dual x-ray absorptiometry. The vertebral bodies were randomly assigned to receive either a unicortical (51 bodies) or bicortical (48 bodies) Caspar cervical plating screw. The initial insertion torque was measured using a digital electronic torque wrench, and the force required to withdraw the screw from the vertebral body was determined. The mean BMD for the total group of 99 was 0.787 ± 0.154 g/cm2, the mean insertion torque was 0.367 ± 0.243 newton-meters, and the mean pullout force was 210.4 ± 158.1 newtons. A significant correlation was noted between BMD and torque (p < 0.0001, r = 0.42), BMD and pullout force (p < 0.0001, r = 0.54), and torque and pullout force (p < 0.0001, r = 0.88). Although the BMD of the unicortical and bicortical groups was equivalent (p = 0.92), the insertion torque and pullout force differed significantly (p = 0.02 and p = 0.008, respectively) for the unicortical and bicortical groups. A holding index for each screw and insertion technique was defined as the product of the BMD and insertion torque. The calculated holding index and resultant pullout force were significantly correlated for both techniques of screw insertion (r = 0.92), and a significant difference in holding index was observed with unicortical versus bicortical screw placement (p = 0.04). The determination of BMD and measurement of insertion torque to create a unique holding index provides an assessment of bone—screw interaction and holding strength of the screw, both of which impact on the resultant stability of cervical instrumentation. As the number of cervical plating systems increases, the determination of a holding index for various screws and insertion techniques may assist in the comparison of cervical instrumentation.
Lower number and thinner myelin of large myelinated fibers in human cervical compression radiculopathy
Authors: Oishi Yosuke , Ohnishi Akio , Suzuki Katsumi , Hojo Teruyuki
Published: June 2009

✓ The authors conducted a morphometric investigation of the histopathological alterations in myelinated fibers (MFs) of the nerve roots of C-6, which showed macroscopic indentation, presumably due to cervical spondylotic radiculopathy. In six cadavers, designated as the radiculopathy group, in which the nerve roots of C-6 showed indentation due to compression on one side (indented side) and the remaining nerve roots (normal side) showed a normal appearance macroscopically, morphometric findings of the nerve roots and the MFs on both the indented and normal sides were evaluated and subjected to blind comparison. Seven cadavers with normal-appearing C-6 nerve roots served as controls. In the control group, there were no differences in the morphometric parameters: that is, total transverse fascicular area, total number of small and large MFs, and relationship between myelin thickness and the radius of the axon between the right and left sides in either the ventral or dorsal roots. There was no evidence found of axonal degeneration, ongoing demyelination, or loss of MFs in either the ventral or dorsal roots in the radiculopathy group on the indented side. However, there were significantly lower numbers of large MFs per root and significantly thinner myelin sheaths relative to axon size on the indented side compared with those on the normal side in both the ventral and dorsal roots. These findings are characteristic alterations of the MFs produced by chronic low-grade compression.
Cavernous malformation of the mammillary bodies: neuropsychological implications
Authors: Loesch Daniel V. , Gilman Steven , Del Dotto Jerel , Rosenblum Mark L.
Published: June 2009

✓ The authors present the first documented case of a cavernous malformation of the mammillary bodies. A 34-year-old woman presented with a 2-month history of headaches and acute memory changes. Magnetic resonance imaging studies demonstrated a retrochiasmatic interpeduncular lesion that was initially thought to be a craniopharyngioma. Operative resection confirmed the diagnosis of a cavernous malformation. This particular case is unique in its destruction of the mammillary bodies and presents further evidence of the relationship of these regions to memory. This report is also the first to document results of pre- and postoperative neuropsychological evaluations that specifically address the memory deficits created by destruction of the mammillary bodies.
Clinical study of enlarged infundibular dilation of the origin of the posterior communicating artery
Authors: Endo Shunro , Furuichi Susumu , Takaba Michiyasu , Hirashima Yutaka , Nishijima Michiharu , Takaku Akira
Published: June 2009

✓ Although some aneurysmal dilations of the origin of the posterior communicating artery (PCoA) that are revealed on carotid angiogram are true aneurysms or preaneurysmal lesions, the authors warn that diagnosis should not be based only on the size and shape of the dilation, especially when the PCoA does not fill.

In the present retrospective study, the authors analyzed intraoperative and angiographic findings in 32 patients with 34 lesions of the PCoA that were preoperatively diagnosed as aneurysms. Only 10 of the lesions were true aneurysms (six cases) or enlarged infundibular dilations with reddish bulges (that is, preaneurysmal bulge; four cases) at the origin of the PCoA. All of the other 24 lesions, including one lesion with PCoA occlusion, were merely enlarged infundibular dilations without any wall abnormality.

A well-developed PCoA was observed only in cases of true aneurysm and dilation with reddish bulge. No other clinical or angiographic characteristics proved useful in identifying the type of lesions. These findings may be helpful to the physician in evaluating the clinical features of such lesions and in determining the diagnosis of enlarged infundibular dilation of the PCoA.
Severe thrombocytopenia following intraarterial papaverine administration for the treatment of vasospasm
Authors: Miller Janice A. , Cross DeWitte T. , Moran Christopher J. , Dacey Ralph G. , McFarland Janice G. , Diringer Michael N.
Published: June 2009

✓ Selective intraarterial infusion of papaverine is used in the treatment of symptomatic cerebral vasospasm. The authors report two episodes of severe thrombocytopenia in a patient that were related to intraarterial administration of papaverine. A 70-year-old man with a right internal carotid artery aneurysm underwent craniotomy and aneurysm clipping. He became lethargic 8 days after the hemorrhage occurred. Cerebral angiography revealed moderate vasospasm. In addition to hypervolemic—hypertensive therapy, the patient was treated on two occasions with intraarterial administration of papaverine. Within 24 hours of both treatments he developed severe thrombocytopenia. On one occasion epistaxis requiring transfusion of blood products occurred. Laboratory data support the diagnosis of immune-mediated papaverine-induced thrombocytopenia. The authors conclude that intraarterial administration of papaverine for treatment of vasospasm can be associated with severe, rapidly reversible thrombocytopenia.
Early detection of delayed traumatic intracranial hematomas using near-infrared spectroscopy
Authors: Gopinath Shankar P. , Robertson Claudia S. , Contant Charles F. , Narayan Raj K. , Grossman Robert G. , Chance Britton
Published: June 2009

✓ Delayed intracranial hematomas are an important treatable cause of secondary brain injury in patients with head trauma. Early identification and treatment of these lesions, which appear or enlarge after the initial computerized tomography (CT) scan, may improve neurological outcome. Serial examinations using near-infrared spectroscopy (NIRS) to detect the development of delayed hematomas were performed in 167 patients. The difference in absorbance of light (ΔOD) at 760 nm between the normal and the hematoma side was measured serially during the first 3 days after injury. Twenty-seven (16%) of the patients developed a type of late hematoma: intracerebral hematoma in eight, extracerebral hematoma in six, and postoperative hematoma in 13 patients. Eighteen of the delayed hematomas caused significant mass effect and required surgical evacuation. The hematomas appeared between 2 and 72 hours after admission. In 24 of the 27 patients, a significant increase (> 0.3) in the ΔOD occurred prior to an increase in intracranial pressure, a change in the neurological examination, or a change on CT scan. A favorable outcome occurred in 67% of the patients with delayed hematomas, which suggests that early diagnosis using NIRS may allow early treatment and reduce secondary injury caused by delayed hematomas.
Fast spin—echo magnetic resonance imaging for radiological assessment of neonatal brachial plexus injury
Authors: Francel Paul C. , Koby Myles , Park T. S. , Lee Benjamin C. P. , Noetzel Michael J. , Mackinnon Susan E. , Henegar Martin M. , Kaufman Bruce A.
Published: June 2009

✓ Neurosurgical management of birth-related brachial plexus palsy involves observing the patient for a period of several months. Operative intervention is usually undertaken at 3 to 6 months of age or more in infants who have shown little or no improvement in affected muscle groups. Ancillary tests such as electromyography and nerve conduction studies are occasionally useful. No radiological study has been consistently helpful in operative planning, except for contrast computerized tomography (CT) myelography, which requires general anesthesia in infants. This is because the infant's small size exceeds the functional resolution of the imaging modalities.

This report describes the use of a special sequence of magnetic resonance (MR) imaging entitled “fast spin echo” (FSE-MR). Unlike CT myelography, this technique provides high-speed noninvasive imaging that allows clinicians to evaluate preganglionic nerve root injuries without the use of general anesthesia and lumbar puncture. The utility of this technique is illustrated in three cases, two involving either infraclavicular exploration or a combination of infraclavicular and supraclavicular exposure based on FSE-MR findings. The FSE-MR imaging offers an excellent alternative to contrast CT myelography in evaluation of infants with birth-related brachial plexus injuries.
Direct thrombosis of experimental aneurysms with cellulose acetate polymer (CAP): technical aspects, angiographic follow up, and histological study
Authors: Sugiu Kenji , Kinugasa Kazushi , Mandai Shinya , Tokunaga Koji , Ohmoto Takashi
Published: June 2009

✓ Experimental aneurysms were created using a microsurgical technique to produce anastomosed venous pouches in the bilateral common carotid arteries of 12 dogs. The 24 aneurysms were then thrombosed via an endovascular approach with injection of a cellulose acetate polymer (CAP) solution that the authors have developed for use as a liquid thrombotic material. Angiography performed 1 to 4 weeks after CAP injection revealed complete thrombosis of the aneurysm with patency of the parent artery in 16 aneurysms. Histological analysis disclosed that the aneurysmal orifice in these cases was completely covered with newly formed endothelial cells 2 weeks after CAP thrombosis. Three other aneurysms exhibited parent artery occlusion caused by protrusion of the CAP mass through the aneurysmal orifice into the parent artery; this was thought to be caused by over-injection of the CAP solution. Histological analysis of the remaining five aneurysms, initially shown to have incomplete occlusion, revealed that they each possessed a residual neck that was partially covered with endothelial cells. No rupture of the aneurysms or migration of CAP into the distal arteries was observed.

These results suggest that using an endovascular approach, direct thrombosis of cerebral aneurysms with CAP is safe and effective. This technique may prove to be an alternative treatment for such aneurysms. However, there is a potential risk of regrowth or rupture of aneurysms that retain a residual neck and long-term follow-up studies will be required to evaluate this issue.
Spinal cord astrocytoma: pathological and treatment considerations
Authors: Minehan Kern J. , Shaw Edward G. , Scheithauer Bernd W. , Davis Dean L. , Onofrio Burton M.
Published: June 2009

✓ Seventy-nine patients underwent surgery, with or without radiation therapy, for astrocytoma of the spinal cord. There were 43 tumors (54%) classified as pilocytic astrocytoma and 25 (32%) as diffuse fibrillary astrocytoma. Eleven tumors (14%) could not be classified other than as astrocytoma, “type not otherwise specified.” The 10-year overall survival rate for all 79 patients was 50% but significantly differed by histological type: 81% for patients with pilocytic astrocytoma compared to 15% for those with diffuse fibrillary astrocytoma. Tumor grade by the Kernohan, et al., or St. Anne—Mayo methods was also a significant predictor of survival in patients with diffuse fibrillary astrocytoma. The extent of surgical resection (biopsy vs. subtotal resection vs. gross total resection) did not significantly impact survival among patients with pilocytic or nonpilocytic astrocytomas of the spinal cord, although there was a trend toward poorer survival in patients undergoing some degree of resection as opposed to biopsy. Postoperative radiation therapy improved survival but did so more for diffuse fibrillary astrocytoma than pilocytic astrocytoma.

In this series, histological type was the most significant predictor of survival in patients with astrocytoma of the spinal cord. The survival rate was highest in patients who underwent biopsy followed by postoperative radiation therapy.
Posterior cervical spine fusion with tension-band wiring
Authors: Lovely Thomas J. , Carl Allen
Published: June 2009

✓ In this study the authors detail their experience with posterior tension-band wiring for stabilization of the subaxial cervical spine. Fifty-five patients underwent fusion for trauma (41 patients), degenerative disease (13 patients), and tumor (one patient). The fusion rate was 96% (50 of 52 patients) and postoperative immobilization was accomplished by means of a Philadelphia collar in the majority of cases.

Tension-band wiring provides a stable construct that is simple to perform, requires fusion of a minium number of motion segments, and allows early mobilization with only a hard collar needed for support. The details of the technique, which has been modified from preliminary descriptions, are discussed.