bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmaxillosphenoidal approach to tumors invading the medial compartment of the cavernous sinus
Authors: Fraioli Bernardo , Esposito Vincenzo , Santoro Antonio , Iannetti Giorgio , Giuffrè Renato , Cantore Gianpaolo
Published: June 2009

✓ A transmaxillosphenoidal approach was used to remove sellar tumors invading the cavernous sinus. This procedure, a widening of the standard transsphenoidal approach to the sella turcica, uses the sublabial or transnasal route in which the medial wall of the maxillary sinus is laterally dislocated. This method provides good exposure of the prominences of bone above the carotid artery which lies on the posterolateral wall of the sphenoid sinus. This bone area is the key to opening the cavernous sinus inferomedially and removing lesions within its medial compartment.

The inferomedial approach takes an entirely extracerebral route so that tumors invading the cavernous sinus through its medial wall are approached inferomedially following the direction of tumor growth. It also allows direct visualization of the intracavernous carotid artery during tumor removal, thus sparing the cranial nerves, which run on the opposite side. Adequate surgical exposure of a pituitary adenoma is achieved with a custom-made sphenoidal retractor with asymmetric blades, the shorter blade holding aside the thin medial wall of the maxillary sinus.

Between October, 1989, and July, 1993, 11 patients with tumors invading the cavernous sinus underwent surgery via this approach; 10 had pituitary adenomas and one had a craniopharyngioma. Eight tumors were treated by primary operation: four tumors were totally and four subtotally (> 80%) removed; one tumor already operated on elsewhere was totally removed; and of two tumors already operated on and irradiated, one was subtotally removed and the other only partially (approximately 40%) removed owing to marked postirradiation scarring. None of the patients suffered permanent cranial nerve deficit and all but one showed marked clinical improvement.
Microvascular anatomy of the anterior surface of the medulla oblongata and olive
Authors: Akar Ziya C. , Dujovny Manuel , Gómez-Tortosa Estrella , Slavin Konstantin V. , Ausman James I.
Published: June 2009

✓ The arterial supply and the microanatomy of the anterior surface of the medulla oblongata and olive were studied in 11 cadaveric specimens, with investigation of the size, course, and length of the arteries. Two distinct anatomical entities divide the vascular supply in this region: 1) the pyramid, which is the anterior surface of the medulla; and 2) the olive, which is adjacent to the lateral aspect of the pyramid. Primary vascularization of the pyramid was via small branches of the anterior spinal artery, a branch of the vertebral artery. Minute perforators from the anterior spinal artery were found in all specimens. Arterial supply to the olive varied by location: its anterior aspect was primarily supplied by the anterior spinal artery; the upper portion of the posterior aspect of the olive was supplied by the vertebral artery, the anterior inferior cerebellar artery, and the basilar artery; and the middle and lower portions of the posterior aspect were fed by the vertebral artery and posterior inferior cerebellar artery. These arteries supplied the medulla through the small branches directed toward the olive.

The authors observed a wide anastomotic net connecting the small arteries in this area. These patterns of microvascular supply of the pyramid and olive may deepen the understanding of clinical and pathological conditions resulting from arterial occlusion. The existence of an anastomotic net may account for the rare incidence of medullary infarction in the olive region.
Congenital cystic supratentorial hemangioblastoma
Authors: Richmond Bryan K. , Schmidt John H.
Published: June 2009

✓ The first documented case of congenital supratentorial hemangioblastoma is presented, occurring in a 3-week-old infant. Extensive review of the literature revealed approximately 83 cases of supratentorial hemangioblastoma; however, only one of these occurred in the first year of life, and that case was not presented in detail.
Linear accelerator radiosurgery for arteriovenous malformations: the relationship of size to outcome
Authors: Friedman William A. , Bova Frank J. , Mendenhall William M.
Published: June 2009

✓ Between May, 1988 and August, 1993, 158 patients with arteriovenous malformations (AVMs) were treated radiosurgically at the University of Florida. A mean dose of 1560 cGy was directed to the periphery of the lesions, which had a mean volume of 9 cc (0.5 to 45.3 cc). One hundred thirty-nine of these individuals were treated with one isocenter. The mean follow-up interval was 33 months with clinical information available on 153 of these patients. Patients were followed until magnetic resonance (MR) studies suggested complete AVM thrombosis. An arteriogram was then performed, if possible, to verify occlusion status. If arteriography revealed any persistent nidus at 36 months posttreatment, the residual nidus was re-treated.

Outcome categories of AVMs analyzed included the following possibilities: 1) angiographic cure; 2) angiographic failure; 3) re-treatment; 4) MR image suggested cure; 5) MR image suggested failure; 6) patient refused follow-up evaluation; 7) patient lost to follow-up study; or 8) patient deceased. The endpoints for success or failure of radiosurgery were as follows: angiographic occlusion (success), re-treatment (failure), and death due to AVM hemorrhage (failure). Fifty-six patients in this series reached one of the endpoints. Successful endpoints were seen in 91% of AVMs between 1 and 4 cc in volume, 100% of AVMs 4 to 10 cc in volume, and 79% of AVMs greater than 10 cc in volume.

The more traditional measure of radiosurgical success, percentage of angiograms showing complete obliteration, was obtained in 81% of AVMs between 1 and 4 cc in volume, 89% of AVMs between 4 and 10 cc in volume, and 69% of AVMs greater than 10 cc in volume. A detailed analysis of the relationship of all outcome categories to size is presented.
Deep central arteriovenous malformations of the brain: the role of endovascular treatment
Authors: Hurst Robert W. , Berenstein Alex , Kupersmith Mark J. , Madrid Mary , Flamm Eugene S.
Published: June 2009

✓ Cerebral deep central arteriovenous malformations (AVMs) are uncommon lesions associated with considerable difficulty in treatment. The authors report a series of 14 deep central AVMs treated by endovascular methods and examine the present role of endovascular treatment. This treatment used alone resulted in complete obliteration of AVMs in approximately 15% of cases and reduction in 50% to a size permitting treatment by means of radiosurgery. Reversal of previous neurological signs and symptoms occurred in 35.7% of embolized patients. Overall, nearly 80% of patients had either complete obliteration of the lesion, reduction to a size allowing radiosurgical treatment, or reversal of previous neurological deficits. There were treatment complications in 14.3% of the cases. Endovascular treatment methods may make a significant contribution to the therapy of AVMs that have a particularly poor course and are difficult to treat by other means.
One-stage internal fixation and anterior fusion in complex cervical spinal disorders
Authors: Johnston Francis G. , Crockard H. Alan
Published: June 2009

✓ The authors describe their experience with the Morscher titanium cervical plate with cancellous locking screws in the management of complex cervical spine disorders. Fifty patients (32 males and 18 females) with a mean age of 54 years (range 10 to 84 years) underwent anterior spinal fixation that extended two to five vertebral bodies, using a titanium cervical plate and autogenous bone graft. Surgeries were performed for a variety of reasons: one for a congenital lesion, five for spinal neoplasms, nine for trauma, and 35 for degenerative arthritides. Ten patients had symptomatic kyphoses due to previous laminectomy, failed anterior surgery, or trauma. Satisfactory fixation and fusion with no neurological deterioration was obtained in all but two cases. Specific complications included six cases of dysphagia, one of sepsis, one of Horner's syndrome, and one case in which the patient had a fatal myocardial infarction the night after surgery. At the end of the follow-up period, fusion was found to have occurred in all remaining cases with no outstanding implant-related problems.
Vertical facet splitting: a special variant of rotary dislocations of the cervical spine
Authors: Sim Ernst
Published: June 2009

✓ A special variant of rotary displacement of the cervical spine with vertical splitting of an inferior articular process by its articulating partner is reviewed. Eighteen patients with unilaterally locked facet joints confirmed by computerized tomography were seen between 1986 and 1991. Five patients presented with vertical split fractures of an inferior articular process by impaction of the superior process of the subjacent vertebra. This specific fracture pattern is not accounted for in current classifications. Four males and one female with a mean age of 31 years (range 16 to 49 years) were affected. Three of the patients showed no neurological deficits. One patient presented with cerebral contusion and paresis of the right upper extremity, and in one patient the posterior funiculus was involved. Three of the injuries had been sustained recently; the other two were of longer duration. Surgical treatment was chosen in the three cases of recent injury. In two cases surgery was prompted by neurological deficits; in the third case impaction was felt to be of inadequate depth. Surgery consisted in fracture reduction and interbody fusion using plates. The two cases of long-term fractures were treated conservatively, and ankylosis of the facet joints eventually provided adequate stability. If radicular or spinal symptoms are absent, this special variant of locked facet joints can successfully be treated conservatively leaving the rotary displacement uncorrected, provided impaction is adequately deep. The author's experience has shown that indications for surgical management are relative rather than absolute in this fracture variant and that use of computerized tomography is essential to establish the fracture pattern.
Nitric oxide synthase and guanylate cyclase levels in canine basilar artery after subarachnoid hemorrhage
Authors: Kasuya Hidetoshi , Weir Bryce K. A. , Nakane Masaki , Pollock Jennifer S. , Johns Lydia , Marton Linda S. , Stefansson Kari
Published: June 2009

✓ Endothelium-dependent vasodilation may be impaired during cerebral vasospasm following subarachnoid hemorrhage. Under normal circumstances nitric oxide (NO) released by endothelial cells induces relaxation of smooth muscle by activating the soluble form of guanylate cyclase within muscle cells. In this study the levels of both endothelial NO synthase, the enzyme that produces NO, and soluble guanylate cyclase were determined in canine basilar arteries in a double-hemorrhage model using Western blot immunoassays. Thirty dogs were assigned to three groups: Group D0, control; Group D2, dogs sacrificed 2 days after cisternal injection of blood; and Group D7, dogs given double cisternal injections of blood and sacrificed 7 days after the first injection. Constriction of the basilar artery was confirmed by arterial angiography. Portions of the affected arteries or the corresponding region in control animals were solubilized for sodium dodecylsulfate—polyacrylamide gel electrophoresis and Western blotting. A specific monoclonal antibody against endothelial NO synthase was used. The extract from basilar arteries showed two bands on the blots: 135 kD, characteristic of endothelial NO synthase, and 120 kD, which may be a degradation product of the enzyme. The densitometer values of the bands were presented as percentages of D0 control values. Although the total signal in the D7 group was less than that of the D0 control group (D2, 97% ± 22%; D7, 78% ± 40%), it was not statistically significant. The proportion of the 135-kD form decreased between Groups D0 and D7, but the difference was not significant. A single major band corresponding to the α-subunit of soluble guanylate cyclase was seen at 70 kD in the basilar artery extracts. The signals of D2 and D7 samples were 69%± 40% and 25% ± 18%, respectively. There was a significant difference between D7 and D0 (p < 0.001). The reduced expression of soluble guanylate cyclase may be related to the impairment of endothelium-dependent vasodilation in vasospasm.
Antagonism of neutrophil adherence in the deteriorating stroke model in rabbits
Authors: Lindsberg Perttu J. , Sirén Anna-Leena , Feuerstein Giora Z. , Hallenbeck John M.
Published: June 2009

✓ Adhesion of leukocytes to the endothelium can occur in a few hours after the onset of ischemia, and the actions of leukocytes have been suggested to aggravate reperfusion injury. Adhesion is a prerequisite for the harmful leukocyte actions. Rapid mediation of leukocyte adhesion and aggravation of reperfusion injury can occur through production of platelet-activating factor (PAF). The authors hypothesized that prevention of leukocyte adhesion during ischemia reperfusion would have beneficial effects and that these effects might be enhanced by a PAF antagonist. To test this hypothesis, rabbits were anesthetized with pentobarbital and subjected to severe spinal cord ischemia (25 minutes) followed by 30 minutes of reperfusion, at which time either vehicle, antibody against the CD11/CD18 (anti-CD) leukocyte adhesion molecule (1 mg/kg), or the anti-CD and PAF antagonist, WEB 2086 (3 mg/kg), was administered intravenously and the animals were monitored for 6.5 hours. Using a score from 0 to 5, recovery of motor function was improved at 5.5 hours by the CD antibody (2.0 ± 0.5 versus 0.4 ± 0.2 in the six animals in the vehicle group, p < 0.05). No further improvement was induced by WEB 2086 in the six anti-CD treated animals (1.6 ± 0.7). Spinal cord blood flow (laser Doppler flowmetry) at 6 hours was at the preischemic level in the control animals (−7% ± 20%), but clearly increased in the anti-CD group (+73% ± 29%, p < 0.5). The severity of blood-brain barrier damage in the spinal cord gray matter was decreased by the treatments. Extravasation of intravenously injected Evans blue albumin (EBA), measured by detection of EBA fluorescence, was reduced by approximately 50% in both treated groups (p < 0.05). The number of morphologically normal motor neurons in the lumbar anterior horns of the infarcted spinal cord showed protection in the seven animals in the anti-CD treated group at 6.5 hours: 12.7 ± 1.7 versus 5.3 ±1.6 (vehicle), p < 0.05 without an additional effect by PAF antagonist 12.2 ± 2.6 (anti-CD + WEB 2086). Our results suggest that ultraacute treatment of reperfusion injury based on special inhibition of leukocyte effects may be beneficial. Platelet-activating factor antagonism failed to enhance this therapeutic effect, which may suggest dependency on a common mechanism.
Monitoring visual evoked potentials during retraction of the canine optic nerve: protective effect of unroofing the optic canal
Authors: Akabane Akira , Saito Kiyoshi , Suzuki Yoshio , Shibuya Masato , Sugita Kenichiro
Published: June 2009

✓ To evaluate the effects of unroofing the optic canal during retraction of the optic nerve, the authors monitored changes in visual evoked potentials (VEPs) stimulated by a light-emitting diode in the canine model. At rest, an early VEP wave was reliably observed with an amplitude of 8.2 ± 0.6 µV and a latency of 51.5 ± 0.7 msec; this wave was named N50. The intracranial optic nerve was retracted using a weight of 5, 10 or 50 g. The earliest change in VEP noted during retraction was a reduction in N50 wave amplitude. The length of time required until N50 amplitude decreased to 50% of the control group (T50) was 10.7 ± 1.8 minutes with a weight of 5 g, 4.9 ± 0.7 minutes with 10 g, and 2.9 ± 0.4 minutes with 50 g, with statistically significant differences between the groups. Retraction of the optic nerve with all weights finally resulted in the disappearance of the N50 wave. The amplitude of the N50 wave recovered fully to control size when retraction was released immediately after the wave disappeared. The time course of amplitude recovery did not differ significantly between groups. Unroofing the optic canal prolonged the T50 during retraction significantly to 20.7 ± 2.9 minutes with a weight of 5 g, 18.9 ± 4.2 with 10 g, and 9.0 ± 2.4 with 50 g. These results demonstrate that unroofing the optic canal can protect the optic nerve from damage during operations that require optic nerve retraction.
The use of intraarterial papaverine in the management of vasospasm complicating arteriovenous malformation resection
Authors: Morgan Michael K. , Day Maurice J. , Little Nicholas , Grinnell Verity , Sorby William
Published: June 2009

✓ The authors report two cases of treatment by intraarterial papaverine of cerebral vasospasm complicating the resection of an arteriovenous malformation (AVM). Both cases had successful reversal of vasospasm documented on angiography. In the first case sustained neurological improvement occurred, resulting in a normal outcome by the time of discharge. In the second case, neurological deterioration occurred with the development of cerebral edema. This complication was thought to be due to normal perfusion pressure breakthrough, on the basis of angiographic arterial vasodilation and increased cerebral blood flow.

These two cases illustrate an unusual complication of surgery for AVMs and demonstrate that vasospasm (along with intracranial hemorrhage, venous occlusion, and normal perfusion pressure breakthrough) should be considered in the differential diagnosis of delayed neurological deterioration following resection of these lesions. Although intraarterial papaverine may be successful in dilating spastic arteries, it may also result in pathologically high flows following AVM resection. However, this complication has not been seen in our experience of treating aneurysmal subarachnoid hemorrhage by this technique.
Cerebrovascular carbon dioxide reactivity assessed by intracranial pressure dynamics in severely head injured patients
Authors: Yoshihara Masaaki , Bandoh Kuniaki , Marmarou Anthony
Published: June 2009

✓ Appropriate management of intracranial pressure (ICP) in severely head injured patients depends in part on the cerebral vessel reactivity to PCO2; loss of CO2 reactivity has been associated with poor outcome. This study describes a new method for evaluating vascular reactivity in head-injured patients by determining the sensitivity of ICP change to alterations in PCO2. This method was combined with measurements of the pressure volume index (PVI), which allowed calculation of blood volume change necessary to alter ICP. The objective of this study was to investigate the ICP response and the blood volume change corresponding to alterations in PCO2 and to examine the correlation of responsivity and outcome as measured on the Glasgow Outcome Scale.

The PVI and ICP at different end-tidal PCO2 levels produced by mild hypo- and hyperventilation were obtained in 49 patients with Glasgow Coma Scale scores of less than 8 and over a wide range of PCO2 (25 to 40 mm Hg) in eight patients. Given the assumption that the PVI remained constant during alteration of PaCO2, the estimated blood volume change per torr change of PCO2 was calculated by the following equation: BVR = PVI × Δlog(ICP)/ΔPCO2, where BVR = blood volume reactivity. The data in this study showed that PVI remained stable with changes in PCO2, thus validating the assumption used in the blood volume estimates. Moreover, the response of ICP to PCO2 alterations followed an exponential curve that could be described in terms of the responsivity indices to capnic stimuli. It was found that responsivity to hypocapnia was reduced by 50% compared to responsivity to hypercapnia measured within 24 hours of injury (p < 0.01). The sensitivity of ICP to estimated blood volume changes in patients with a PVI of less than 15 ml was extremely high with only 4 ml of blood required to raise ICP by 10 mm Hg. The authors conclude from these data that, following traumatic injury, the resistance vessels are in a state of persistent vasoconstriction, possibly due to vasospasm or compression. Furthermore, BVR correlates with outcome on the Glasgow Coma Scale, indicating that assessment of cerebrovascular response within the first 24 hours of injury may be of prognostic value.
Intramedullary spinal cord lipomas
Authors: Lee Mark , Rezai Ali R. , Abbott Rick , Coelho Daniel H. , Epstein Fred J.
Published: June 2009

✓ Spinal cord lipomas are rare lesions, accounting for approximately 1% of all spinal cord tumors. True intramedullary spinal cord lipomas are extremely rare and are represented in the literature as scattered, single case reports. The authors present a series of six patients with intramedullary spinal cord lipomas managed at our institution from July, 1985 to July, 1993. The patients' ages ranged from 8 to 45 years. Four patients presented with newly diagnosed tumors and two had undergone previous surgery. Patients usually presented with long histories of disability followed by rapid progression of their symptoms. Most patients were in poor neurological condition on presentation. Presenting symptoms included spinal pain, dysesthetic sensory changes, gait difficulties, weakness, and incontinence. Three patients had cervical tumors, two had cervicothoracic tumors, and one patient had a thoracic tumor. Diagnostic studies, including magnetic resonance imaging, were obtained in all patients. No patient exhibited any form of spinal dysraphism or had a dural defect. All patients underwent decompressive, subtotal resections of 40% to 70% of their lesions. Follow-up times ranged from 12 to 96 months. All patients had resolution of their pain, but they generally showed no neurological improvement. As of their most recent follow-up visit, none of the patients was neurologically normal; three can function independently, although with neurological deficits. The other three patients cannot function independently and have severe neurological deficits. The authors conclude that patients with intramedullary spinal cord lipoma who present with significant neurological compromise have a very poor prognosis with regard to neurological function and generally show no improvement with surgical resection.
Continuous intraoperative electromyographic recording during spinal surgery
Authors: Beatty Robert M. , McGuire Peggy , Moroney Jean M. , Holladay Frank P.
Published: June 2009

✓ One hundred fifty patients underwent spinal surgery for radiculopathy; of these, 120 underwent lumbar surgery and 30 had cervical operations. All of the surgeries were performed to alleviate symptoms due to disc herniation, spondylosis, or both. During the surgical procedures continuous intraoperative electromyograph recordings were taken from the muscle corresponding to the involved nerve root. In baseline recordings taken in the operating room 10 minutes before lumbar surgery, electrical discharge or firing was recorded from the muscle in 18% (22 of 120 patients) of the cases. Once the nerve was decompressed, muscle firing ceased. Electrical discharges were produced with regularity on nerve root retraction.

This study concludes that continuous electromyograph monitoring can be accomplished easily and yields valuable information that indicates when the nerve root is adequately decompressed or when undue retraction is exerted on the root.
Interstitial radiosurgery of low-grade gliomas
Authors: Kreth Friedrich W. , Faist Michael , Warnke Peter C. , Roβner Reinhard , Volk Benedikt , Ostertag Christoph B.
Published: June 2009

✓ The treatment of patients with low-grade gliomas remains a subject of controversy, especially with respect to new treatment modalities such as interstitial radiosurgery (brachytherapy), radiosurgery, and stereotactic radiotherapy. In a retrospective analysis conducted between 1979 and 1991, the authors studied the results of interstitial radiosurgery in 455 patients with low-grade gliomas (World Health Organization (WHO) Grade I + WHO Grade II) with regard to survival time, quality of life, the risk of malignant transformation, and the risk profile of the treatment concept. Interstitial radiosurgery with iodine-125 was performed using permanent (1979–1985) or temporary implants (after 1985) with low-dose rates (≤ 10 cGy/hr) and a reference dose of 60 to 100 Gy calculated to the outer rim of the tumor.

The 5- and 10-year survival rates in patients with pilocytic astrocytomas (97 patients) were 84.9% and 83%, and in patients with WHO Grade II astrocytomas (250 patients) 61% and 51%, respectively. Five-year survival rates for patients with oligoastrocytomas (60 patients), oligodendrogliomas (27 patients), and gemistocytic astrocytomas (21 patients) were 49%, 50%, and 32%, respectively. In the group with WHO Grade II gliomas, young age and a good performance status were associated with a better prognosis. Unfavorable factors were midline shift, enhancement on computerized tomography (CT) scan, and tumor recurrence after previous radiotherapy or surgery. Tumor location had no influence on the prognosis (247 patients in this series had deep-seated tumors). Malignant transformation was the major cause of death. Important risk factors for malignancy were the patient's age, tumor enhancement in CT scan, and tumor recurrence after previous surgery or radiotherapy. Perioperative mortality was 0.9% and perioperative morbidity was 1.7%. Radiogenic complications were observed in 2.7% of all patients, most often in larger tumors and after using permanent implants. The authors conclude that interstitial radiosurgery represents a specific treatment modality for selected patients with unifocal circumscribed low-grade gliomas with a diameter of less than 4 cm in any location. The efficacy of this treatment lies in the same range as the best results after surgery and radiotherapy.
Diagnostic yield of stereotactic brain biopsy guided by positron emission tomography with [18F]fluorodeoxyglucose
Authors: Levivier Marc , Goldman Serge , Pirotte Benoît , Brucher Jean-Marie , Balériaux Danielle , Luxen André , Hildebrand Jerzy , Brotchi Jacques
Published: June 2009

✓ The aim of the present study was to determine whether routine integration of positron emission tomography (PET) with18F-labeled fluorodeoxyglucose (FDG) in the planning of stereotactic brain biopsy increases the technique's diagnostic yield. Forty-three patients underwent combined FDG-PET— and computerized tomography (CT)-guided stereotactic biopsy of intracranial lesions according to a previously described technique. In 36 patients, an area of abnormal FDG uptake was used to guide at least one stereotactic biopsy trajectory. A total of 90 stereotactic trajectories were performed; among them, 55 were based on FDG-PET—defined targets and 35 were based on CT-defined targets. Histological diagnosis was obtained in all patients, but six of the 90 trajectories were nondiagnostic; all six were based on targets defined by CT only. Differences between the diagnostic yield of trajectories based on FDG-PET—defined targets and those based on CT-defined targets were statistically significant in patients with contrast-enhanced lesions, but not in patients with nonenhancing lesions. These results support the view the FDG-PET may contribute to the successful management of brain tumor patients requiring stereotactic biopsy. Because no significant increase in discomfort or morbidity related to the technique was found, it is suggested that the development of similar techniques integrating PET data in the planning of stereotactic biopsy should be considered by centers performing stereotactic surgery and having access to PET technology.
Radiation-induced meningioma with a 63-year latency period
Authors: Kleinschmidt-DeMasters Bette K. , Lillehei Kevin O.
Published: June 2009

✓ Meningiomas are known to be induced by low-, moderate-, and high-dose radiation therapy, with an average time interval to tumor appearance of 35, 26, and 19 to 24 years, respectively. An inverse relationship is suggested between the dose of radiation given and the time to tumor formation. The authors report a case of a 68-year-old woman who received orthovoltage radiotherapy at 5 years of age for a presumed (nonbiopsy confirmed) right cerebellar tumor and developed multiple meningiomas in the radiation portals 63 years later. Like many radiation-induced meningiomas, the tumor was histologically atypical and multiple in its presentation. This case suggests that previous radiotherapy may confer a low, but life-long, risk for meningioma occurrence.
Isolated toxoplasmosis of the thoracic spinal cord in a patient with acquired immunodeficiency syndrome
Authors: Resnick Daniel K. , Comey Christopher H. , Welch William C. , Martinez A. Julio , Hoover William W. , Jacobs George B.
Published: June 2009

✓ Toxoplasmosis and lymphoma are the two most common causes of intraparenchymal cerebral mass lesions in patients with acquired immunodeficiency syndrome (AIDS). The clinical and radiographic features of the intracranial lesions have been well described. Because of the high frequency of toxoplasmosis in the AIDS population, common therapy for patients presenting with intracranial mass lesions consists of an empirical trial of anti-Toxoplasma chemotherapy, with biopsy reserved for cases demonstrating features considered to be more consistent with lymphoma, or for lesions that do not improve despite adequate anti-Toxoplasma treatment. A similar treatment algorithm does not exist for intramedullary lesions of the spinal cord.

The authors describe a patient who presented with paraparesis resulting from an isolated thoracic intramedullary lesion. An open biopsy of the lesion revealed characteristic structures containing Toxoplasma tachyzoites. The clinical and radiographic presentation of the lesion is discussed, the available literature is reviewed, and a treatment strategy for spinal cord lesions in AIDS patients is proposed.
Phase II trial of tirilazad in aneurysmal subarachnoid hemorrhage
Authors: Haley E. Clarke , Kassell Neal F. , Alves Wayne M. , Weir Bryce K. A. , Hansen Carolyn Apperson , _ _
Published: June 2009

✓ Tirilazad mesylate, a 21-aminosteroid free-radical scavenger, has been shown to ameliorate cerebral vasospasm and reduce infarct size in animal models of subarachnoid hemorrhage (SAH) and focal cerebral ischemia. In preparation for performing large-scale clinical trials in humans with aneurysmal SAH, the safety of varying doses of tirilazad was tested in a randomized, double-blind, vehicle-controlled, sequential dose-escalation study at 12 Canadian neurosurgical centers. Two hundred forty-five patients with an aneurysmal SAH documented by angiography were enrolled in the study sequentially within 72 hours of hemorrhage. The patients were assigned to one of three dosage tiers: receiving 0.6 mg/kg, 2 mg/kg, or 6 mg/kg tirilazad or vehicle per day intravenously in divided doses through Day 10 following the SAH. All patients also received oral nimodipine. No serious side effects of tirilazad treatment were identified at any of the three doses, despite close monitoring of hepatic and cardiac toxicity. A trend toward improvement in overall 3-month patient outcome was seen in the 2 mg/kg per day tirilazad-treated group compared to the outcomes in the vehicle-treated groups. We conclude that tirilazad mesylate is safe in SAH patients at doses up to 6 mg/kg per day for up to 10 days and is a promising drug for the treatment of patients with aneurysmal SAH.
Thrombosed growing giant aneurysms of the vertebral artery: growth mechanism and management
Authors: Nagahiro Shinji , Takada Akira , Goto Satoshi , Kai Yutaka , Ushio Yukitaka
Published: June 2009

✓ Results in three patients with thrombosed giant aneurysms of the vertebral artery are reported. Each of the aneurysms presented as a mass lesion. On postcontrast computerized tomography and magnetic resonance imaging, each aneurysm demonstrated a patent lumen and intrathrombotic vascular channels. Two patients died and were autopsied, and the other patient was successfully treated. Pathological examination revealed that the aneurysms had staged clots, an open lumen, intrathrombotic channels with endothelial lining, and aneurysmal walls with intimal thickening. The authors suggest that the development of the intrathrombotic capillary channels may be an important factor in the growth of thrombosed giant aneurysm of the vertebral artery. Trapping of the aneurysm followed by aneurysmectomy appears to be the best treatment for this type of aneurysm.
Surgical treatment of jugular foramen schwannomas
Authors: Samii Madjid , Babu Ramesh P. , Tatagiba Marcos , Sepehrnia Abolghassem
Published: June 2009

✓ Sixteen patients with schwannomas of the jugular foramen were operated on in the Department of Neurosurgery of the Nordstadt Hospital in Hannover, Germany, between 1986 and 1992. Patients with neurofibromatosis were excluded. The records of the 16 patients were retrospectively reviewed. There were five women and 11 men (mean age 43 years) with a symptom duration ranging from 6 months to 20 years (mean 5 years). The predominant symptoms were hearing loss, hoarseness, and cerebellar symptoms. Computerized tomography (CT), magnetic resonance (MR) imaging, and angiography were performed in all 16 patients. Depending on the radiological and surgical features, the tumors were classified into four types: Type A, a tumor primarily at the cerebellopontine angle with minimal enlargement of the jugular foramen (eight cases); Type B, a tumor primarily at the jugular foramen with intracranial extension (two cases); Type C, a primarily extracranial tumor with extension into the jugular foramen (one case); and Type D, a dumbbell-shaped tumor with both intra- and extracranial components (five cases).

A retromastoid suboccipital craniectomy was performed for Type A tumors, and a combined cervical-mastoidectomy for Types B, C, and D. Total tumor removal was achieved in all cases. There was no operative mortality. Postoperative complications were cerebrospinal fluid leakage in one patient and mastoiditis in two patients. The follow-up period ranged from 12 to 42 months (mean 22 months). All patients were alive at the last follow-up review, and CT and/or MR imaging showed no tumor recurrence.
Validation of transcranial Doppler ultrasound with a stereotactic neurosurgical technique
Authors: Monsein Lee H. , Razumovsky Alex Y. , Ackerman Stacey J. , Nauta Haring J. W. , Hanley Daniel F.
Published: June 2009

✓ Vessel identification during a transcranial Doppler (TCD) ultrasound examination is usually based on well-established inferential criteria without confirmation by imaging. Part of a routine study involves taking measurements from the M1 segment of the middle cerebral artery (MCA) and the A1 segment of the anterior cerebral artery (ACA) at the points of maximum mean linear blood flow velocity (LBFV). The authors tested the hypothesis that insonation is from the midpoints of the M1 and A1 segments during clinical TCD examinations.

Conventional hand-held TCD examinations were performed on five volunteers. The points of maximum mean LBFV of the M1 and A1 segments of the MCA and ACA were located. Measurements were also taken from the midpoints of the M1 and A1 segments using a magnetic resonance (MR) imaging-guided stereotactic TCD technique. Values for depths of insonation and maximum mean LBFV obtained with the two techniques were compared. There was no significant difference between the two techniques for the measured values of depth of insonation of either the individual vessels (p > 0.11) or the aggregate (p = 0.46). There was a significant difference between the aggregate maximum mean LBFV measurements (p = 0.0022). The hand-held technique systematically produced higher maximum mean LBFV than the MR-guided stereotactic technique. The authors conclude that when using traditional criteria for TCD examination of the ACA and MCA, the points of insonation approximate the middle of the A1 and M1 segments.
Trigeminal evoked potentials in somatosensory cortex of the Macaca mulatta
Authors: McCarthy Gregory , Allison Truett
Published: June 2009

✓ Somatosensory evoked potentials (SEPs) obtained in response to stimulation of the median nerve, posterior tibial nerve, lips, tongue, palate, and pharynx were recorded in four monkeys (Macaca mulatta) under light barbiturate anesthesia. In agreement with the results of SEP recordings in humans and single-unit recordings in monkeys, there is a medial-to-lateral representation in somatosensory cortex of the hand, lips, and tongue. There is a discontinuity in the representation of the upper mouth: the tongue representation is interposed between a medial region (near the lip representation), usually representing the lateral hard palate and gum, and a lateral region (near the lateral sulcus), usually representing the central hard palate. For all types of trigeminal stimulation, root mean square (RMS) voltage maps show maxima over somatosensory cortex. Laminar recordings demonstrated that trigeminal SEPs recorded from the cortical surface are generated in somatosensory cortex in areas 1, 2, and 3b.

Median nerve and posterior tibial nerve stimulation did not evoke SEPs in the surface cortex near the lateral sulcus, suggesting that the most lateral portion of the postcentral gyrus is not a part of the second somatosensory area (SII). This lateral region may contain the representation of posterior intraoral structures, but it was not possible to confirm this assumption by stimulation of the soft palate or pharynx.
Mapping of dermatomes of the lower extremities based on an animal model
Authors: Takahashi Yuzuru , Takahashi Kazuhisa , Moriya Hideshige
Published: June 2009

✓ Previous dermatome drawings have been developed on the basis of investigations in humans and thus differ among investigators. The authors recently reported detailed dermatomes of the rat hindlimb that were mapped by electrical stimulation of spinal nerves and observation of plasma extravasation in the corresponding skin. In this paper a new human dermatome chart is proposed that has been reconstructed from rat dermatomes; the accuracy of previously reported dermatomes is also discussed. These newly defined dermatomes are arranged as serial semicircles, not as bands extending spirally from the low back down to the lower extremity as shown by Keegan. The posterior pattern differs markedly from that of any previously described charts in that the S-2 dermatome is “interposed” within the S-1 dermatome. This study clarifies the basic arrangement of lower-extremity dermatomes. Based on the present chart, it is concluded that Bonica's dermatomes are the most accurate among those previously reported.
Differential effects of vincristine and phenytoin on the proliferation, migration, and invasion of human glioma cell lines
Authors: Tonn Jörg-Christian , Haugland Hans Kristian , Saraste Jaakko , Roosen Klaus , Laerum Ole Didrik
Published: June 2009

✓ The aim of this study was to investigate the antimigratory and antiinvasive potential of vincristine sulfate (VCR) on human glioma cells and to analyze whether phenytoin (5,5-diphenylhydantoin; DPH) might act synergistically with VCR. Vincristine affects the cytoplasmic microtubules; DPH has been reported to enhance VCR cytotoxicity in murine cells. In two human glioma cell lines, GaMG and D-37MG, we found VCR to reduce monolayer growth and colony formation in a dose-dependent fashion at concentrations of 10 ng/ml and above. Phenytoin increased the cytotoxic and cystostatic effects of VCR in monolayer cells but not in spheroids.

Multicellular spheroids were used to investigate directional migration. A coculture system of GaMG and D-37MG spheroids with fetal rat brain aggregates was used to analyze and quantify tumor cell invasion. A dose-dependent inhibition of migration and invasion by VCR was observed in both cell lines without further enhancement by DPH. Immunofluorescence microscopy with antibodies against α-tubulin revealed dose-dependent morphological alterations in the microtubules when the cells were exposed to VCR but not after incubation with DPH. Based on the combination of standardizedin vitromodel systems currently in use and the present data, the authors strongly suggest that VCR inhibits migration and invasion of human glioma cells. This is not altered by DPH, which inhibits cell proliferation in combination with VCR.
Current implications for the efficacy of noninvasive screening for occult intracranial aneurysms in patients with a family history of aneurysms
Authors: Obuchowski Nancy A. , Modic Michael T. , Magdinec Michele
Published: June 2009

✓ Although the technology exists for accurate noninvasive screening for intracranial aneurysms, the efficacy of screening depends on several key parameters of the natural history of aneurysms. Recent studies suggest that the prevalence of intracranial aneurysms may reach 20% in the subpopulation of patients with a family history of these lesions; other key parameters are less certain. The authors investigated factors that impact the efficacy of screening to establish interim guidelines. Three plausible models for the natural history of aneurysms were constructed. For each model the monetary cost of screening and the average gain in life expectancy were computed for a range of screening ages and prevalence rates. It is shown that the efficacy of screening depends on the pattern of aneurysm rupture. If aneurysms develop and rupture rapidly, then screening has no benefit. On the other hand, if aneurysms remain at risk for some time after formation, then screening may improve average life expectancy depending on when it occurs. The authors recommend that patients with a positive family history of aneurysms who are 30 years of age or younger be screened. This recommendation is based on the belief that the gains attributable to screening, assuming a constant rupture rate, outweigh the losses attributable to screening using a decreasing rupture rate model.
Histological findings in giant aneurysms treated with Guglielmi detachable coils
Authors: Molyneux Andrew J. , Ellison David W. , Morris James , Byrne James V.
Published: June 2009

✓ The authors report the pathological and histological findings in two patients with giant partially thrombosed aneurysms who were treated by means of Guglielmi detachable coils with subtotal occlusion of the aneurysms. Autopsies of these patients were performed 2 and 6 months after endovascular treatment. The histological findings revealed coils embedded in largely unorganized thrombus in the aneurysms; there was no clear reduction in size of the aneurysms over the period. There was no evidence of endothelialization of the aneurysm neck demonstrated in either case. The significance of these findings is discussed.
Association of venous and true arteriovenous malformation: a rare entity among mixed vascular malformations of the brain
Authors: Meyer Bernhard , Stangl Armin P. , Schramm Johannes
Published: June 2009

✓ In this article the authors report the case of a mixed cerebrovascular malformation in which a true arteriovenous malformation (AVM), harboring a nidus, is associated with a venous malformation that serves as the draining vein for the nidus. Despite the authors' preoperative rationale for exclusive extirpation of the AVM, an inadvertent injury and the obliteration of the venous malformation generated delayed postoperative neurological deterioration, which could clearly be attributed to venous hemorrhagic infarction. Because this is only the second instance of this type of mixed vascular malformation of the brain reported, which also underscores the concept of nonsurgical treatment of venous malformations, the authors discuss the diverse literature regarding mixed vascular malformations and the treatment of venous malformations.
Papillary craniopharyngioma: a clinicopathological study of 48 cases
Authors: Crotty Thomas B. , Scheithauer Bernd W. , Young William F. , Davis Dudley H. , Shaw Edward G. , Miller Gary M. , Burger Peter C.
Published: June 2009

✓ Two distinct clinicopathological variants of craniopharyngioma exist: the classic adamantinomatous type and a recently described papillary form that predominates in adults and reportedly behaves in a less aggressive manner. The present study describes the clinicopathological features of 48 patients with papillary craniopharyngioma treated at the Mayo Clinic between 1910 and 1994. An additional four tumors were found to have histological features of both adamantinomatous and papillary craniopharyngioma. Whereas adamantinomatous tumors typically occur in adolescent patients, the mean age of the 48 patients (23 males and 25 females) with papillary craniopharyngioma was 44.7 years (range 10 to 74 years). Presenting clinical features included visual impairment (84%), headache (68%), and pituitary insufficiency (anterior 42%; posterior 27%). Preoperative computerized tomography (CT) and magnetic resonance (MR) imaging in 17 patients typically revealed a noncalcified, partially cystic mass that enhanced peripherally and contained mural nodules (67%). Many (41%) of the lesions involved or extended into the third ventricle on imaging. At first surgery, gross total tumor removal was achieved in 17 patients (36%) and subtotal resection in 30 patients (64%) in whom tumor resection was attempted. Tumor recurrence was noted in two patients who underwent gross total removal. Tumor-free survival rates of 100% and 78% were obtained in patients who underwent gross total and subtotal resection at initial surgery, respectively. Postoperative radiation therapy was beneficial to patients having undergone a subtotal resection, with an increase in tumor-free survival from 26% to 86%.

Aside from well-documented morphological distinctions, papillary craniopharyngiomas differ from adamantinomatous tumors in several important respects. These include the almost exclusive occurrence of papillary tumors in adulthood and their more uniform appearance on both CT and MR imaging. However, a preliminary analysis of our data suggests there are no significant differences between the two lesions with respect to resectability, efficacy of radiation therapy, and overall survival.