bluuebunny/crossref_metadata_2025 huggingface dataset:
The radium bomb: Harvey Cushing and the interstitial irradiation of gliomas
Authors: Schulder Michael , Loeffler Jay S. , Howes Anthony E. , Alexander Eben , Black Peter McL.
Published: June 2009

✓ Harvey Cushing performed over 2000 operations on patients with brain tumors, including 832 for gliomas. He implanted radioactive radium needles, known as a “radium bomb,” in a small number of these patients. He was not impressed with the results and did not pursue this method of treatment in a serious way. The authors present here Cushing's little-known experience with brachytherapy and discuss the reasons for his lack of interest in this technique, despite his advocacy of radiotherapy for certain lesions. An interesting perspective is offered for contemporary neurosurgeons involved in the treatment of brain tumors with cranial irradiation.
Cranial chordomas in children and adolescents
Authors: Borba Luis A. B. , Al-Mefty Ossama , Mrak Robert E. , Suen James
Published: June 2009

✓ Chordomas are rare tumors that usually occur in adults. This report describes four cases of intracranial chordomas treated in patients 20 years of age or younger by the senior author (O.A.M.) during a 4-year period. The authors also reviewed the literature on pediatric patients, which revealed that the clinical presentations, histological patterns, and behaviors of these tumors differ considerably depending on whether the patient is younger or older than 5 years of age. The younger population had a wider range of presenting symptoms, a greater prevalence of atypical histological findings with aggressive behavior, a greater range of cellularity than the classic chordomas, and a higher instance of metastasis; it showed no chondroid component compared to a 17.1% instance in the older patients. The prognosis for patients with a chordoma is related directly to the histological pattern of the tumor; the atypical chordoma carries a poor prognosis. The prognoses for children older than 5 years of age with a classic or chondroid tumor were not significantly different (p = 0.788). At follow up, the difference in survival rates between patients undergoing surgery plus radiation therapy and those who had surgery alone was statistically significant (p = 0.00446). No correlation was found between radical resection or radiation therapy and an improved prognosis for patients younger than 5 years of age who had a tumor with an atypical histological pattern. This study identifies and delineates the distinction between these age groups and provides a review of the potential prognostic factors.
Neurochemical monitoring using intracerebral microdialysis in patients with subarachnoid hemorrhage
Authors: Persson Lennart , Valtysson Johann , Enblad Per , Wärme Per-Erik , Cesarini Kristina , Lewén Anders , Hillered Lars
Published: June 2009

✓ The authors have developed a method for routine monitoring of disturbances in brain energy metabolism and extracellular levels of excitatory amino acids using intracerebral microdialysis in 10 patients with subarachnoid hemorrhage. Microdialysis was conducted for periods ranging from 6 to 11 days after ictus. Altogether, 16,054 chemical analyses from 1647 dialysate samples were performed. Concentrations of the energy-related substances lactate, pyruvate, glucose, and hypoxanthine were measured, and the lactate/pyruvate ratio was calculated. The excitatory amino acids glutamate and aspartate were measured. The microdialysis data were matched with computerized tomography findings, clinical course, and outcome. The results support the concepts that microdialysis is a promising tool for chemical monitoring of the human brain and that extracellular fluid levels of lactate, lactate/pyruvate ratio, glucose, hypoxanthine, and glutamate are useful markers of disturbances in brain energy metabolism in neurointensive care patients. These results have generated a working hypothesis that the pattern of these extracellular markers may help differentiate between various causes of energy perturbations, such as hypoxia and different degrees of ischemia. The correlation between the dialysate levels of excitatory amino acids and outcome supports the concept of glutamate receptor overactivation in acute human brain injury.
Comparison of syringopleural and syringosubarachnoid shunting in the treatment of syringomyelia in children
Authors: Vernet Olivier , Farmer Jean-Pierre , Montes José L.
Published: June 2009

✓ Case records from the Montreal Children's Hospital containing the diagnosis of shunted syringomyelia were retrospectively reviewed. From 1984 to 1994, 31 patients had their syrinx treated by either syringopleural (19 cases, Group A) or syringosubarachnoid (13 cases, Group B) shunting. One patient was included in both groups.

Associated diagnoses included: in Group A, two cases of Chiari I and 14 of Chiari II malformations, 14 cases of shunted hydrocephalus, 13 cases of spina bifida aperta, and three cases of spina bifida occulta; Group B, four cases of Chiari I and two of Chiari II malformations, four cases of shunted hydrocephalus, two cases of spina bifida aperta, and five cases of spina bifida occulta. Eight Group A and six Group B patients had undergone prior posterior fossa decompression. Motor deficits predominated in both groups and arachnoiditis was a uniform operative finding.

Neurological follow-up examinations showed 11 Group A patients improved and eight stabilized, whereas on magnetic resonance imaging, 12 cavities appeared to have collapsed, five were markedly reduced, and one had increased. One patient underwent reoperation for pleural effusions and one for shunt displacement. In Group B, one patient improved, eight stabilized, three worsened neurologically, and one was lost to follow-up review. Radiologically, one cavity appeared to have collapsed, six were significantly reduced, two were unchanged, and three had enlarged.

The authors conclude that syringopleural shunting is a valuable option for controlling syringomyelia in patients without Chiari malformation or in patients who have previously undergone a craniovertebral decompression or are otherwise asymptomatic from their Chiari malformation.
Effects of prednisone on ventriculoperitoneal shunt function in hydrocephalus secondary to cysticercosis: a preliminary study
Authors: Suastegui Roman Roberto A. , Soto-Hernández José Luis , Sotelo Julio
Published: June 2009

✓ In a prospective open study, 15 patients with hydrocephalus secondary to cysticercosis who required insertion of a ventriculoperitoneal (VP) shunt were treated with 50 mg of prednisone given orally three times a week. Treatment began in the 1st postoperative week, with isoniazid and pyridoxine administered daily as antituberculous chemoprophylaxis. The drug regimen was continued with close follow up for 24 months. Clinical status, Karnofsky performance status (KPS) scores, and postoperative course in the prednisone-treated group were compared with 30 control patients with hydrocephalus due to cysticercosis. The control patients were matched by age and sex, underwent surgical shunting in the same period, and were followed routinely by the neurosurgery staff. Lumbar cerebrospinal fluid (CSF) was studied at 2, 16, and 32 weeks postoperatively in the prednisone group. At 24-month follow up two (13%) of 15 patients in the prednisone group and 18 (60%) of 30 patients in the control group required surgical shunt revisions for symptomatic shunt obstruction (p = 0.002). Follow-up studies of CSF performed at 32 weeks in the prednisone group revealed improvement of abnormal values with statistically significant differences for glucose (p < 0.02). Serial imaging studies in the prednisone group revealed persistence of cysticercal cysts with no change in size. Mean initial KPS scores were similar in both groups. At the end of the follow-up period, the mean KPS score was significantly higher in the prednisone group (p = 0.003). Prednisone and chemoprophylactic drugs were well tolerated. These results suggest that in selected patients with hydrocephalus secondary to cysticercosis, intermittent long-term prednisone therapy after VP shunting may reduce shunt malfunction and improve the functional status of the patients.
Brain tissue pressure gradients created by expanding frontal epidural mass lesion
Authors: Wolfla Christopher E. , Luerssen Thomas G. , Bowman Robin M. , Putty Timothy K.
Published: June 2009

✓ A porcine model was used to study the regional intracranial pressure (ICP) differences caused by a frontal mass lesion. Intraparenchymal ICP monitors were placed in the right and left frontal lobes, right and left temporal lobes, midbrain, and cerebellum. A frontal epidural mass lesion was created by placing a balloon catheter through a burr hole into the right frontal epidural space. A computer was used to acquire data from all monitors at 50-msec intervals. The balloon was expanded by 1 cc over a period of 1 second every 5 minutes and maximum pressure immediately before and during expansion was determined for each balloon volume at each site. Prior to expansion of the mass, the morphology of the cerebellum pressure tracing was different from that seen in all supratentorial regions. Also, pressures in the midbrain, at baseline, were slightly but significantly lower than pressures in the frontal and temporal regions. During expansion of the mass, a pressure differential that increased as the size of the mass increased developed between intracranial regions. Furthermore, the regional pressures were found to vary in a consistent fashion expressed by the formula RF = LF > RT = LT > MB > CB, in which RF and LF are the right and left frontal lobes, RT and LT are the right and left temporal lobes, MR is the midbrain, and CB is the cerebellum. The study shows that an expanding epidural mass reproducibly results in a gradient of brain parenchymal pressure. This gradient results in parenchymal pressures that are significantly different in each region of the brain depending on the proximity of that region to the epidural mass. The results of this study have implications for clinical ICP monitoring and therapy.
Loss of nitric oxide synthase immunoreactivity in cerebral vasospasm
Authors: Pluta Ryszard M. , Thompson B. Gregory , Dawson Ted M. , Snyder Solomon H. , Boock Robert J. , Oldfield Edward H.
Published: June 2009

✓ To determine the distribution of nitric oxide synthase (NOS) in the primate cerebral artery nervi vasorum and to examine the potential role of NOS in cerebral vasospasm after subarachnoid hemorrhage (SAH) in primates, the distribution of NOS immunoreactivity (NOS-IR) in the major cerebral arteries was examined immunohistochemically in cynomolgus monkeys by the use of whole, mounted preparations of the circle of Willis. In four normal monkeys, NOS-IR was localized to the endothelial and adventitial layers of the large cerebral arteries. On the abluminal side, NOS-IR staining was densely concentrated in perivascular nerve fibers (nervi vasorum) of the anterior circulation. Staining was less prominent in the posterior circulation. In six monkeys with vasospasm on Day 7 after placement of preclotted arterial blood to form an SAH around the right middle cerebral artery (MCA) (42% ± 8.3% decrease of MCA area, mean ± standard deviation), NOS-IR was virtually absent in nerve fibers around the spastic right MCA but was normal on the contralateral side. In five monkeys in which vasospasm resolved by Day 14 after SAH (36% ± 14% decrease of right MCA area on Day 7, and 5% ± 14% decrease on Day 14), NOS-IR was also absent in the right MCA adventitial nerve fibers and remained normal in the left MCA. Adventitial NOS-IR was also normal in cerebral vessels of a sham-operated, nonspastic monkey.

These findings provide further evidence that nitric oxide (NO) functions as a neuronal transmitter to mediate vasodilation in primates and indicate a role for adventitial NO in the pathogenesis of cerebral vasospasm after SAH in humans.
Combined fetal neural transplantation and nerve growth factor infusion: effects on neurological outcome following fluid-percussion brain injury in the rat
Authors: Sinson Grant , Voddi Madhu , McIntosh Tracy K.
Published: June 2009

✓ This study was designed to evaluate the histological and behavioral impact of fetal neural transplantation with and without neurotrophin infusion in rats subjected to traumatic brain injury using a clinically relevant model of lateral fluid-percussion brain injury. Adult male Sprague—Dawley rats received lateral fluid-percussion brain injury of moderate severity (2.1–2.3 atm). Twenty-four hours after injury, minced fetal cortical grafts (E16) were stereotactically transplanted into the site of injury cavity formation (in 32 rats). Ten control animals received injections of saline. A third group of 29 animals that received transplants also underwent placement of a miniosmotic pump (immediately after transplantation) to continuously infuse nerve growth factor (NGF) directly into the region of graft placement for the duration of the experiment. A fourth group of eight animals underwent transplantation of fetal cortical cells that had been dissociated and placed in suspension. Animals were evaluated at 72 hours, 1 week, and 2 weeks after injury for cognitive function (using the Morris water maze), posttraumatic motor dysfunction, and transplant survival and morphology (using Nissl and modified Palmgren's silver staining techniques). Robust survival of whole-tissue transplants was seen in 65.6% of animals and was not increased in animals receiving NGF infusion. Animals receiving transplants of cell suspension had no surviving grafts. Brain-injured animals receiving transplants showed significant cognitive improvements compared with controls at the 2-week evaluation. Significantly improved memory scores were seen at all evaluation times in animals receiving both NGF and transplants compared with injured controls and compared with animals receiving transplants alone at the 72-hour and 1-week evaluations. Neurological motor function scores were significantly improved in animals receiving transplants alone and those receiving transplants with NGF infusion. Histological evaluation demonstrated differentiation of grafted cells, decreased glial scarring around transplants when compared with control animals, and the presence of neuronal fibers bridging the interface between graft and host. This study demonstrates that fetal cortical cells transplanted into the injured cortex of the adult rat can improve both posttraumatic cognitive and motor function and interact with the injured host brain.
Recurrent transient quadriparesis after minor cervical trauma associated with bilateral partial agenesis of the posterior arch of the atlas
Authors: Torreman Martijn , Verhagen Ivo T. H. J. , Sluzewski Menno , Kok Alexander J. M. , van Rooij Willem Jan
Published: June 2009

✓ The case of a 33-year-old woman with bilateral partial agenesis (type D) of the posterior arch of the atlas and recurrent transient quadriparesis due to contusion of the spinal cord after minor cervical trauma is described. At least some patients with type C or D congenital anomalies of the posterior arch of the atlas are prone to transient quadriparesis; thus a more aggressive management is advocated for them. Radiological and surgical findings showing the possible causative mechanism are presented and a review of the literature is given.
Acquired cerebral arteriovenous malformation in a child with moyamoya disease
Authors: Schmit Berndt P. , Burrows Patricia E. , Kuban Karl , Goumnerova Liliana , Scott R. Michael
Published: June 2009

✓ The authors report a unique case involving a 2-year-old child with idiopathic moyamoya disease who presented with cerebral infarctions and seizures. On initial evaluation, computerized tomography (CT) showed a left parietal infarct and angiograms demonstrated early moyamoya disease with no evidence of arteriovenous malformation (AVM). Approximately 9 years later, angiography and magnetic resonance (MR) imaging revealed an AVM centered on the same region of the left parietal lobe. Angiographic, CT, and MR images are presented that demonstrate the progression of moyamoya disease and de novo development of the AVM in the infarct site. The possible role of angiogenesis in the etiology of acquired AVMs and moyamoya disease is discussed.
Chromaffin cell survival and host dopaminergic fiber recovery in a patient with Parkinson's disease treated by cografts of adrenal medulla and pretransected peripheral nerve
Authors: Date Isao , Imaoka Takashi , Miyoshi Yasuyuki , Ono Takeshi , Asari Shoji , Ohmoto Takashi
Published: June 2009

✓ A 55-year-old woman with severe Parkinson's disease was treated by cografting adrenal medulla with pretransected peripheral nerve into the bilateral caudate nuclei. The patient showed modest improvement of her akinesia; this effect persisted for 1 year after transplantation, when she suddenly died from upper gastrointestinal bleeding unrelated to the grafting procedure. At autopsy, a large number of tyrosine hydroxylase—immunoreactive chromaffin cells were observed within the caudate graft sites and a dense network of host dopaminergic fibers was visualized. This autopsy finding is very important for the field of experimental and clinical chromaffin cell grafting because it is the first evidence that cografts using pretransected peripheral nerve might enhance the survival of chromaffin cells and the recovery of host dopaminergic fibers in humans suffering from Parkinson's disease.
Percutaneous endoscopic treatment of suprasellar arachnoid cysts: ventriculocystostomy or ventriculocystocisternostomy?
Authors: Decq Philippe , Brugières Pierre , Le Guerinel Caroline , Djindjian Michel , Kéravel Yves , Nguyen Jean-Paul
Published: June 2009

✓ The use of an endoscope in the treatment of suprasellar arachnoid cysts provides an opening of the upper and lower cyst walls, thereby allowing the surgeon to perform a ventriculocystostomy (VC) or a ventriculocystocysternostomy (VCC). To discover which procedure is appropriate, magnetic resonance (MR)—imaged cerebrospinal fluid (CSF) flow dynamics in two patients were analyzed, one having undergone a VC and the other a VCC using a rigid endoscope. Magnetic resonance imaging studies were performed before and after treatment, with long-term follow-up periods (18 months and 2 years). The two patients were reoperated on during the follow-up period because of slight headache recurrence in one case and MR—imaged CSF flow dynamics modifications in the other. In each case surgery confirmed the CSF flow dynamics modifications appearing on MR imaging.

In both cases, long-term MR imaging follow-up studies showed a secondary closing of the upper wall orifice. After VCC, however, the lower communication between the cyst and the cisterns remained functional.

The secondary closure of the upper orifice may be explained as follows: when opened, the upper wall becomes unnecessary and tends to return to a normal shape, leading to a secondary closure. The patent sylvian aqueduct aids this phenomenon, as observed after ventriculostomy when the aqueduct is secondarily functional.

The simplicity of the VCC performed using endoscopic control, which is the only procedure to allow the opening in the cyst's lower wall to remain patent, leads the authors to advocate this technique in the treatment of suprasellar arachnoid cysts.
Intraoperative ultrasound for monitoring anterior cervical vertebrectomy
Authors: Goodkin Robert , Haynor David R. , Kliot Michel
Published: June 2009

✓ The authors describe the use of intraoperative ultrasonography with a small high-frequency (15 mHz) probe for evaluation of the extent of lateral bone removal during anterior cervical vertebrectomy. The relationship of the bone resection margins to the lateral aspect of the spinal cord was visualized. Postoperative computerized tomography scans revealed the extent of bone removal to be similar to that demonstrated by ultrasound. Intraoperative ultrasonography may be useful during anterior cervical surgery to assure adequate decompression of the spinal canal and spinal cord.
A new method for inserting the atrial end of a ventriculoatrial shunt
Authors: Harrison Michael J. , Welling Blake G. , Dubois Jeffrey J.
Published: June 2009

✓ This technical note describes a simple percutaneous mechanism for placement of the atrial end of ventriculoatrial shunts. The method is fast, efficient, and involves no neck dissection. No special equipment is required. Placement involves the technique of central line insertion familiar to all surgeons. This new method has been used successfully in one adult and one pediatric patient.
Value of postoperative surveillance imaging in the management of children with some common brain tumors
Authors: Steinbok Paul , Hentschel Stephen , Cochrane D. Douglas , Kestle John R. W.
Published: June 2009

✓ The rationale for obtaining surveillance computerized tomography (CT) scans or magnetic resonance (MR) images in pediatric patients with brain tumors is that early detection of recurrence may result in timely treatment and better outcome. The purpose of this study was to investigate the value of surveillance cranial images in a variety of common pediatric brain tumors managed at a tertiary care pediatric hospital.

A retrospective chart review was performed of children with astrocytoma of the cerebral hemisphere, cerebellum, optic chiasm/hypothalamus, or thalamus; cerebellar or supratentorial high-grade glioma; supratentorial ganglioglioma; posterior fossa or supratentorial primitive neuroectodermal tumor (PNET); and posterior fossa ependymoma. Data were analyzed to determine the frequency with which recurrences were identified on a surveillance image and how the type of image at which recurrence was identified related to outcome.

In 159 children, 17 of 44 recurrences were diagnosed by surveillance imaging. The percentage of recurrences identified by surveillance imaging was 64% for ependymoma, 50% for supratentorial PNET, 43% for optic/hypothalamic astrocytoma, and less than 30% for other tumors. The rate of diagnosis of recurrence per surveillance image varied from 0% to 11.8% for different tumor types. Only for ependymomas did there appear to be an improved outcome when recurrence was identified prior to symptoms.

Our results indicate that, using the protocols outlined in this study, surveillance imaging was not valuable in identifying recurrence of cerebellar astrocytoma or supratentorial ganglioglioma during the study period, but was probably worth-while in identifying recurrence of posterior fossa ependymoma and optic/hypothalamic astrocytoma and, possibly, medulloblastoma. Surveillance protocols could be made more effective by individualizing them for each type of tumor, based on current data on the patterns of recurrence.
Adjuvant combined modality therapy for malignant meningiomas
Authors: Chamberlain Marc C.
Published: June 2009

✓ Malignant meningiomas constitute 10% to 15% of all meningiomas and limited information exists regarding adjuvant treatment of these aggressive primary brain tumors. Fourteen patients (eight men, six women), ranging in age from 28 to 61 years (median 51 years), were prospectively treated for primary malignant meningiomas according to an institutional protocol. All patients underwent surgery (gross-total in four and subtotal resection in 10 patients) followed in 2 to 4 weeks by involved-field radiotherapy (range 59–60 Gy, median dose 60 Gy). Two to 4 weeks after radiotherapy all patients were treated with adjuvant chemotherapy that included cyclophosphamide, adriamycin, and vincristine (CAV). Patients who underwent gross-total resection received three cycles, whereas those with subtotal resection received six cycles of CAV.

Four patients required CAV dose reduction due to myelosuppression, and in three patients, myelosuppression prevented administration of the planned course of CAV. Four patients required transfusions (four received red blood cells, three received platelets), and two developed neutropenic fever without bacteriological documentation. Neuroradiographic response included three partial responses and 11 with stable disease. The median time to tumor progression was 4.6 years (range 2.2–7.1 years) and median survival was 5.3 years (range 2.6–7.6 years). The author concludes that combined modality therapy for the treatment of malignant meningiomas is associated with acceptable toxicity and a modest improvement in survival when compared to patients treated with surgery alone.
Medical management in the endovascular treatment of carotid-cavernous aneurysms
Authors: Polin Richard S. , Shaffrey Mark E. , Jensen Mary E. , Braden Lisa , Ferguson Robert D. G. , Dion Jacques E. , Kassell Neal F.
Published: June 2009

✓ Carotid-cavernous aneurysms account for between 1.9% and 9.0% of intracranial aneurysms. Entirely intercavernous aneurysms are believed to have a relatively benign course, with cranial nerve findings or headache being the usual initial symptomatology; however, subarachnoid hemorrhage or carotid-cavernous fistula formation can result from rupture. Over the past 15 years endovascular parent artery occlusion has essentially replaced surgical carotid occlusion as the treatment of choice. The authors describe a series of 39 consecutive patients at the University of Virginia Health Sciences Center who underwent endovascular treatment of a carotid-cavernous aneurysm. Aggressive invasive hemodynamic monitoring and maintenance of a state of normo- to mild hypervolemia in the asymptomatic patient was used throughout the periprocedural period. Rapid institution of hypervolemic—hypertensive therapy can reverse early neurological deficits related to hypoperfusion in these patients. Only one individual managed with this protocol developed neurological deficits not reversible with hypertensive-hypervolemic therapy. Heparin therapy was administered for 48 hours after occlusion, with patients receiving subsequent aspirin therapy for 6 months to combat distal embolism secondary to thrombosis. Long-term complications were not seen in patients receiving aneurysm trapping; however, two individuals with proximal carotid occlusion developed late optic neuropathy and one had recurrent transient ischemic attacks that ceased with supraclinoidal carotid clipping.
Traumatic subarachnoid hemorrhage as a predictable indicator of delayed ischemic symptoms
Authors: Taneda Mamoru , Kataoka Kazuo , Akai Fumiharu , Asai Toshiharu , Sakata Ikuhiro
Published: June 2009

✓ This report provides findings of an investigation of the influence of traumatic subarachnoid hemorrhage on the development of delayed cerebral ischemia caused by vasospasm. The authors prospectively studied 130 patients with closed-head trauma, who exhibited subarachnoid blood on admission computerized tomography (CT) scans. Ten (7.7%) of these patients developed delayed ischemic symptoms between Days 4 and 16 after the head injury. They consisted of three (3.0%) of 101 patients with small amounts of subarachnoid blood and seven (24.1%) of 29 patients with massive quantities of subarachnoid blood on admission CT scans. In each of the 10 patients, severe vasospasm was demonstrated by angiography performed soon after development of ischemic symptoms. There was a close correlation between the main site of the subarachnoid blood and the location of severe vasospasm. In seven of the patients, follow-up CT scans showed development of focal ischemic areas in the cerebral territories corresponding to the vasospastic arteries.

These results demonstrate that traumatic subarachnoid hemorrhage, especially if massive, is a predictable indicator of delayed ischemic symptoms.
Traumatic aneurysms and arteriovenous fistulas of intracranial vessels associated with penetrating head injuries occurring during war: principles and pitfalls in diagnosis and management
Authors: Amirjamshidi Abbass , Rahmat Hamid , Abbassioun Kazem
Published: June 2009

✓ In the early days of the war between Iran and Iraq, reports of the sudden deaths of soldiers who previously had survived a penetrating head injury suggested the possibility that a late complication, traumatic aneurysm (TA), could be the cause of this catastrophe. In response, the authors planned a prospective study to perform cerebral angiography in victims with penetrating head traumas, especially in those who had artillery shells or bone fragments passing through areas of dense vasculature. Thirty-one TAs and arteriovenous fistulas were documented. Not all of the lesions, however, were deemed appropriate for surgical intervention. Six aneurysms (19.4%) healed spontaneously and shrank or disappeared on repeated serial angiograms. The authors present their cases and discuss the incidence of TAs, their natural course and behavior, and the special problems encountered in managing these interesting and potentially fatal complications of penetrating head injuries.
Temporary vessel occlusion for aneurysm surgery: risk factors for stroke in patients protected by induced hypothermia and hypertension and intravenous mannitol administration
Authors: Ogilvy Christopher S. , Carter Bob S. , Kaplan Stuart , Rich Charles , Crowell Robert M.
Published: June 2009

✓ Temporary vessel occlusion is an effective technique used by microvascular surgeons to facilitate dissection and permanent clipping of cerebral aneurysms; however, several questions remain regarding the overall safety of this technique. To identify technical and patient-specific risk factors for perioperative stroke, the authors examined a series of patients in whom induced hypertension and mild hypothermia and intravenous mannitol administration were used as protection during temporary vessel occlusion for aneurysm clipping. The study comprises a nonconcurrent prospective analysis of 132 consecutive aneurysm clippings performed with the aid of temporary vascular occlusion and a specific antiischemic anesthetic protocol at the Massachusetts General Hospital from 1991 to 1993. Factors studied included duration of the temporary clip application, number of occlusive episodes, patient age and neurological status, presence of preoperative subarachnoid hemorrhage (SAH), and intraoperative aneurysm rupture (“forced” temporary clipping), as well as whether proximal vessel occlusion or complete aneurysm trapping was used. In a univariate analysis, patient age, intraoperative aneurysm rupture, temporary clipping lasting more than 20 minutes, clipping between the 4th and 10th day after SAH, and multiple clipping episodes were all significantly associated with stroke outcome. Multivariate logistic regression revealed that intraoperative aneurysm rupture (relative risk 5.6, p = 0.02) and a duration of temporary clip application that lasted more than 20 minutes (relative risk 9.4, p = 0.04) were independently associated with stroke outcome. Overall, 5.2% of the patients had postoperative clinical strokes. Based on their findings the authors conclude that temporary clipping is a safe adjunct to aneurysm surgery, particularly when the duration of clipping is short.
Effects of a hydroxyl radical scavenger on delayed ischemic neurological deficits following aneurysmal subarachnoid hemorrhage: results of a multicenter, placebo-controlled double-blind trial
Authors: Asano Takao , Takakura Kintomo , Sano Keiji , Kikuchi Haruhiko , Nagai Hajime , Saito Isamu , Tamura Akira , Ochiai Chikayuki , Sasaki Tomio
Published: June 2009

✓ A water-soluble, novel synthetic compound, AVS ((±)-N,N′-propylenedinicotinamide; nicaraven) has no demonstrable vasoactive properties but scavenges hydroxyl radicals in aqueous environmental conditions at neutral pH. Based on the results of preceding experimental and clinical studies showing marked ameliorative effects of AVS on cerebral vasospasm and ischemic brain damage, a multicenter, placebo-controlled double-blind clinical trial was undertaken to verify its beneficial effects on delayed ischemic neurological deficits (DINDs) due to vasospasm and on the overall outcome of patients with subarachnoid hemorrhage (SAH). A total of 162 patients with SAH who had Glasgow Coma Scale scores between 7 and 15 on admission were enrolled in the trial. Drug administration (4 g AVS or 4 g glucose as placebo; infused intravenously for 6–8 hours once a day) was begun within 5 days post-SAH and continued for 10 to 14 days. Intent-to-treat analysis of these patients revealed that the overall incidence of DINDs, which was defined as an exacerbation of impaired consciousness and/or focal neurological deficits, was significantly reduced, by 34.5% (placebo 54.2%, AVS 35.5%; p < 0.05, Mann—Whitney U-test). The Glasgow Outcome Scale (GOS) score at 1 month was significantly improved by AVS (p < 0.05, U-test). At 3 months, the difference in the GOS scores between the groups became marginal on U-tests (p < 0.10), but the percentage of good outcome tended to increase, with a relative increase of 20.3% (AVS 76.3%, placebo 63.4%; p < 0.10, chi-square test), and the cumulative incidence of death was significantly reduced (p < 0.05, log-rank test). No significant adverse reaction attributable to treatment was observed. The usefulness of AVS in therapy for SAH is strongly indicated by the fact that the agent significantly ameliorated DINDs, leading to a marked improvement in the GOS scores at 1 month, as well as a reduction in the cumulative incidence of death by 3 months.
Surgical interruption of leptomeningeal drainage as treatment for intracranial dural arteriovenous fistulas without dural sinus drainage
Authors: Collice Massimo , D'Aliberti Giuseppe , Talamonti Giuseppe , Branca Vincenzo , Boccardi Edoardo , Scialfa Giuseppe , Versari Pietro P.
Published: June 2009

✓ Intracranial dural arteriovenous fistulas (AVFs) have been recognized as acquired lesions that can behave aggressively depending on the pattern of venous drainage. Based on the type of venous drainage, they can be classified as fistulas drained only by venous sinuses, those drained by venous sinuses with retrograde flow in arterialized leptomeningeal veins, and fistulas drained solely by arterialized leptomeningeal veins. Serious symptoms, including hemorrhage and focal deficit, are related to the presence of arterialized leptomeningeal veins. In this paper, the authors report a consecutive series treated between 1988 and 1993 of 20 cases of intracranial dural AVFs with “pure leptomeningeal drainage.” All patients underwent surgical interruption of the leptomeningeal draining veins. Based on the arterial supply, nine patients were managed by direct surgery, whereas 11 patients were prepared for surgery by means of preoperative arterial embolization. Radioanatomical cure of the fistula and good neurological recovery were achieved in 18 cases. Complete obliteration of the fistula was documented angiographically in two cases, but fatal hemorrhage occurred, probably due to partial thrombosis of the venous drainage. Based on this experience, the authors believe that surgical interruption of the draining veins is the best treatment option for intracranial dural AVFs. However, surgical results may be affected by the extension of postoperative thrombosis, which in turn may be related to the degree of preoperative venous engorgement.
Long-term outcome after operation for trigeminal neuralgia in patients with posterior fossa tumors
Authors: Barker Fred G. , Jannetta Peter J. , Babu Ramesh P. , Pomonis Spiros , Bissonette David J. , Jho Hae Dong
Published: June 2009

✓ During a 20-year period, 26 patients with typical symptoms of trigeminal neuralgia were found to have posterior fossa tumors at operation. These cases included 14 meningiomas, eight acoustic neurinomas, two epidermoid tumors, one angiolipoma, and one ependymoma. The median patient age was 60 years and 69% of the patients were women. Sixty-five percent of the symptoms were left sided. The median preoperative duration of symptoms was 5 years. The distribution of pain among the three divisions of the trigeminal nerve was similar to that found in patients with trigeminal neuralgia who did not have tumors; however, more divisions tended to be involved in the tumor patients. The mean postoperative follow-up period was 9 years.

At operation, the root entry zone of the trigeminal nerve was examined for vascular cross-compression in 21 patients. Vessels compressing the nerve at the root entry zone were observed in all patients examined. Postoperative pain relief was frequent and long lasting. Using Kaplan—Meier methods the authors estimated excellent relief in 81% of the patients 10 years postoperatively, with partial relief in an additional 4%.
Prevention of cerebrovasospasm following subarachnoid hemorrhage in rabbits by the platelet-activating factor antagonist, E5880
Authors: Hirashima Yutaka , Endo Shunro , Kato Ryoko , Takaku Akira
Published: June 2009

✓ Recently, an important role of platelet-activating factor (PAF), an inflammation mediator, has been demonstrated in the genesis of cerebral vasospasm following subarachnoid hemorrhage (SAH). In the current study, the authors examined whether intravenous administration of the novel PAF antagonist, E5880, can prevent vasospasm following SAH in rabbits.

A vasospasm model was produced in three groups of rabbits using two subarachnoid injections of autologous arterial blood, followed by intravenous administration of distilled water (control), a low dose of E5880 (0.1 mg/kg in distilled water), or a high dose of E5880 (0.5 mg/kg in distilled water). Neurological deterioration was largely prevented in the rabbits that received E5880. Basilar artery constriction was also reduced by both doses of E5880. Histological examination at autopsy predominantly showed ischemic changes in the brain. Animals in each E5880-treated group exhibited ischemic changes less frequently than those in the control group. Plasma thromboxane B2concentrations were reduced in rabbits treated with E5880. Platelet-activating factor was immunolocalized in the intima and media of the basilar artery in the control group. The PAF immunoreactivity demonstrated in the basilar artery was decreased in the E5880 groups in a dose-dependent manner. Thus, this study provides evidence that PAF may play a role in the pathogenesis of vasospasm after SAH and that intravenous administration of E5880 is a promising approach in preventing vasospasm.
Recurrence of a cerebral arteriovenous malformation after surgical excision
Authors: Gabriel Eric M. , Sampson John H. , Wilkins Robert H.
Published: June 2009

✓ Complete excision of a cerebral arteriovenous malformation (AVM) should eliminate the future risk of an associated intracranial hemorrhage. Because total removal of an AVM may be difficult to assess at the time of surgery, postoperative angiography has become the accepted standard for documenting that the removal has been accomplished. However, even angiographically confirmed excision of an AVM does not completely ensure against rebleeding. Regrowth of an AVM with subsequent hemorrhage can occur. This has been documented in children and is attributed to forces acting on the immature vasculature of these younger patients. The authors report the case of an older patient whose AVM recurred when he was 28 years of age, despite an angiographically proven complete excision, and emphasize that, even in adults, angiographic documentation of total removal does not always eliminate the risk of reformation of an AVM.
The risk of hemorrhage after radiosurgery for arteriovenous malformations
Authors: Friedman William A. , Blatt David L. , Bova Frank J. , Buatti John M. , Mendenhall William M. , Kubilis Paul S.
Published: June 2009

✓ Two hundred and one patients with arteriovenous malformations (AVMs) treated radiosurgically between May 1988 and February 1995 are analyzed in this study. Twelve patients sustained a posttreatment hemorrhage during this period. Pretreatment factors associated with increased hemorrhage risk were identified in 11 of these patients and included arterial aneurysms, venous aneurysms, venous outflow obstruction, periventricular location, prior embolization, and prior surgical treatment. A detailed statistical analysis, using both Poisson regression and parametric survival regression techniques, was undertaken to determine whether radiosurgery had any effect on the risk of hemorrhage, when compared to the natural history of the disease, in those patients in whom a complete angiographic cure was not achieved. No evidence was found to support a statistically significant departure from the natural hemorrhage rate at any time period after radiosurgical treatment. Significant risk factors for hemorrhage appeared to correlate with increasing AVM volume.
Trigeminal evoked potential—monitored thermorhizotomy: a novel approach for relief of trigeminal pain
Authors: Leandri Massimo , Gottlieb Alberto
Published: June 2009

✓ This paper presents a complete method for performing trigeminal thermorhizotomy, guided by neurophysiological data, to relieve tic douloureux. The method involves the use of trigeminal evoked potentials (TEPs) produced by stimulation of the supraorbital, infraorbital, and mental nerves and recorded from electrodes at both the scalp and the trigeminal nerve. To perform the thermorhizotomy, a cannula is modified to produce a concentric bipolar electrode that is suitable for both recording and lesion making. The operating procedure is divided into five steps: Step 1, recording of baseline scalp TEPs from the derivation of the cervical vertex to C-7 to ensure that all stimulating electrodes are correctly placed; Step 2, recording of TEPs from the trigeminal electrode after stimulation of the peripheral nerve trunks to ascertain the electrode's position relative to the root bundles; Step 3, fine positioning of the trigeminal electrode by recording the root activity evoked by stimulation of cutaneous trigger points or of the most painful areas; Step 4, assessing the position of the trigeminal electrode relative to the motor root by stimulating the nerve via the electrode and observing the masseter motor responses; and Step 5, recording scalp TEPs immediately before and after each thermolesion. Thermolesions are made until the scalp-recorded wave W2 decreases its amplitude by 20% to 50% of the original value or until it is delayed by 0.30 msec. This procedure has the potential to enable extremely precise monitoring of the position of the trigeminal electrode relative to the activated fibers and provides very effective monitoring of the extent of the lesion. The authors have performed this procedure with very satisfactory results in 30 patients with trigeminal neuralgia in the second branch.
Stereotactic radiosurgery for trigeminal neuralgia: a multiinstitutional study using the gamma unit
Authors: Kondziolka Douglas , Lunsford L. Dade , Flickinger John C. , Young Ronald F. , Vermeulen Sandra , Duma Christopher M. , Jacques Deane B. , Rand Robert W. , Regis Jean , Peragut Jean-Claude , Manera Luis , Epstein Mel H. , Lindquist Christer
Published: June 2009

✓ A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radiosurgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1–7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11–36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%–90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day–6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief.

A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.
Bifrontal basal interhemispheric approach to craniopharyngioma resection with or without division of the anterior communicating artery
Authors: Shibuya Masato , Takayasu Masakazu , Suzuki Yoshio , Saito Kiyoshi , Sugita Kenichiro
Published: June 2009

✓ The authors describe the use of a bifrontal basal interhemispheric approach with or without division of the anterior communicating artery (ACoA) for removal of large craniopharyngiomas. This approach is a more basal modification of the anterior interhemispheric approach, allowing preservation of most bridging veins. Since 1988, 22 patients underwent operations using this approach to achieve total or near-total excision of large craniopharyngiomas. Division of the ACoA was performed in 11 of 17 patients with retrochiasmatic tumors with no early or late complications related to division of the artery. There were no operative mortalities. Visual improvement (59%) and preservation of the pituitary stalk (64%) were achieved in a high percentage of patients. Preservation of the pituitary stalk correlated well with postoperative pituitary function. The bifrontal basal interhemispheric approach allowed a bilateral, wider operative field with better orientation and views of important neural structures and perforating arteries without requiring combination with other approaches. When the ACoA limited operative exposure, the artery could be divided safely. The authors discuss indications for, and advantages of, the bifrontal basal interhemispheric approach with or without division of the ACoA in the removal of large craniopharyngiomas.
Radiographic and clinical follow-up review of Caspar plates in 49 patients
Authors: Paramore Christopher G. , Dickman Curtis A. , Sonntag Volker K. H.
Published: June 2009

✓ Although they are excellent clinical tools, Caspar anterior cervical plates have not been studied closely with regard to their mechanisms of failure. As more extensive operations are contemplated on older, sicker patients, it is imperative to know when a plating system might be prone to failure and what the mechanism of that failure might be. Therefore, the authors reviewed 49 patients undergoing Caspar plate placement in whom sufficient radiographs were obtained to determine if the fate of the hardware was related to the patient's age, type of operation, and the length of construct. Eleven of 49 patients suffered hardware failure, defined as any amount of screw backout or breakage, plate pullout, or pseudarthrosis. Four patients underwent hardware removal; one underwent posterior fusion for pseudarthrosis. Only two required treatment in a halo brace. There was an eventual fusion rate of 100%, including one fibrous union, and one of the patients who underwent repeat surgery was lost to follow-up review. No graft extrusions or new neurological deficits were incurred as a result of hardware failure. Plate length predicted plate failure in a statistically significant manner. Increasing age and reoperation correlated with plate failure but were not statistically significant in this small number of patients. Telescoping of the bone graft and vertebral bodies, with concomitant migration of the plate and slippage of the screws, was common. However, telescoping was more profound in the group in which the plates failed. The authors conclude that Caspar plate failures are more likely to occur in the elderly and in patients who need longer constructs. Bone fusion can be expected even when the hardware loosens.