bluuebunny/crossref_metadata_2025 huggingface dataset:
Tremor control after pallidotomy in patients with Parkinson's disease: correlation with microrecording findings
Authors: Taha Jamal M. , Favre Jacques , Baumann Thomas K. , Burchiel Kim J.
Published: January 2008

The goals of this study were to analyze the effect of pallidotomy on parkinsonian tremor and to ascertain whether an association exists between microrecording findings and tremor outcome.

Forty-four patients with Parkinson's disease (PD) who had drug-induced dyskinesia, bradykinesia, rigidity, and tremor underwent posteroventral pallidotomy. Using a 1-μ-tip tungsten electrode, microrecordings were obtained through one to three tracts, starting 10 mm above the pallidal base. Tremor severity was measured on a patient-rated, 100-mm Visual Analog Scale (VAS), both preoperatively and 3 to 9 months (mean 6 months) postoperatively.

Preoperatively, tremor was rated as 50 mm or greater in 24 patients (55%) and as less than 25 mm in 13 patients (30%). Postoperatively, tremor was rated as 50 mm or greater in five patients (11%) and less than 25 mm in 29 patients (66%). The difference was significant (p = 0.0001). Four patients (9%) had no postoperative tremor. Tremor improved by at least 50% in eight (80%) of 10 patients in whom tremor-synchronous cells were recorded (Group A) and in 12 (35%) of 34 patients in whom tremor-synchronous cells were not recorded (Group B). This difference was significant (p = 0.03). Tremor improved by at least 50 mm in all (100%) of the seven Group A patients with severe (>= 50 mm) preoperative tremor and in nine (53%) of 17 Group B patients with severe preoperative tremor. This difference was also significant (p = 0.05).

The authors proffer two conclusions: 1) after pallidotomy, tremor improves by at least 50% in two-thirds of patients with PD who have severe (>= 50 mm on the VAS) preoperative tremor; and 2) better tremor control is obtained when tremor-synchronous cells are included in the lesion.
Magnetic resonance image evaluation of pallidotomy lesions: a volumetric and shape analysis
Authors: Burns Jeffrey M. , Wilkinson Steve , Overman John , Kieltyka Jennifer , Lundsgaarde Thorsten , Tollefson Travis , Koller William C. , Pahwa Rajesh , Tröster Alexander I. , Lyons Kelly E. , Batnitzky Solomon , Wetzel Louis , Gordon Michael A.
Published: January 2008

Determination of acute pallidotomy-produced lesion volumes, pre- and postpallidotomy globus pallidus (GP) volumes, and assessment of lesion shape using magnetic resonance (MR) imaging-based computerized segmentation (contouring) and three-dimensional rendering was made in 19 patients. Magnetic resonance image slice thickness (1.5 mm or 6 mm) was not found to be a significant factor influencing contour-based pallidotomy lesion volume estimates. Previously reported lesion volumes produced by pallidotomy have often been estimated using the ellipsoid volume formula. Using 1.5-mm-thick MR sections, contour-based pallidotomy-produced lesion volumes were significantly different from those volumes estimated by the ellipsoid formula. Globus pallidus volumes, estimated by contouring T2-weighted MR images, were bilaterally similar (2.4 ± 0.37 ml [right]; 2.2 ± 0.45 ml [left]). Postoperative GP volumes were found on the contralateral, unlesioned side to be 2 ± 0.45 ml and on the lesioned side to be 1.25 ± 0.45 ml. Using the contralateral, unlesioned side as a reference volume, approximately 39 ± 14% of the GP was visibly affected on the lesioned side. Seventeen of 18 patients had a favorable outcome with reduced dyskinesias and "off" time with improvement in parkinsonian symptoms.

Analysis of computerized three-dimensional rendering of pallidotomy-produced lesions based on MR images showed no relationship between lesioning technique and resulting lesion shape. Important factors in the volumetric analysis of pallidotomy lesions are identified and allow reasonable assessment of the pallidotomy lesion volume and shape and the extent of the affected GP.
Contemporaneous bilateral pallidotomy
Authors: Iacono Robert P. , Carlson Jonathan D. , Kuniyoshi Sandra , Mohamed Aymen , Meltzer Christine , Yamada Shokei
Published: January 2008

To investigate the effects of bilateral posteroventral pallidotomy (PVP) for Parkinson's disease (PD), the authors reviewed the technique and neurological outcome in a number of patients who had undergone bilateral pallidotomy. The authors have previously reported the outcome of PVP in 25 bilateral and 25 unilateral surgeries, rating the patient's postural stability, speech, and total Unified Parkinson's Disease Rating Scale scores. A second, separate group of 23 patients who underwent contemporaneous bilateral PVP were evaluated for early onset idiopathic PD, levodopa failure syndrome, and severe bilateral dyskinesia as well as akinetic “off” states. Cognitive and psychological studies were reviewed in 10 patients who demonstrated preoperative impairments in spatial recognition and memory. Following surgery there were significant improvements in these cognitive deficits and no deficits were incurred by surgery.

Published reports regarding bilateral operations for PD have emphasized the risks of speech and cognitive deficits. This study shows bilateral PVP to be effective, particularly in patients with bilateral symptoms, including disabling dyskinesia. Additionally, bilateral PVP does not cause additional cognitive or speech deficits. The techniques and indications as well as outcomes and complications are presented and discussed in this report in light of their controversial nature.
Management of postoperative infections after spinal instrumentation
Authors: Levi Allan D. O. , Dickman Curtis A. , Sonntag Volker K. H.
Published: January 2008

The authors retrospectively reviewed 452 consecutively treated patients who underwent a spinal instrumentation procedure at a single institution to establish which patients and which surgical approaches might be associated with an increased risk of developing deep wound infections and to determine the efficacy with which the institution's current treatment strategy eradicates these infections. Wound infections occurred in 17 patients (10 men and seven women) with spinal instrumentation (incidence 3.8%). All infections occurred after posterior spinal instrumentation procedures (7.2%); there were no infections after anterior instrumentation procedures regardless of the level. Each patient was assigned an infection risk factor (RF) score depending on the number of RFs identified in an individual patient preoperatively. The mean RF score of patients who developed infections was 2.18, whereas the mean RF score for a procedure-matched, infection-free control group was 0.71. The mean number of days from surgery to clinical presentation was 27.6 days (range 4-120 days), and the mean increase in hospitalization time for the subset of patients who developed infections was 16.6 days. The most common organism isolated from wound cultures was Staphylococcus aureus (nine of 17 cases). Of the 17 patients, five had infections involving multiple organisms. All patients were infection free at a minimum of 8 months follow-up review. The current treatment regimen advocated at this institution consists of operative debridement of the infected wound, a course of intravenous followed by oral antibiotic medications, insertion of an antibiotic-containing irrigation-suction system for a mean of 5 days, and maintenance of the instrumentation system within the infected wound.
Hydroxyurea for treatment of unresectable and recurrent meningiomas. I. Inhibition of primary human meningioma cells in culture and in meningioma transplants by induction of the apoptotic pathway
Authors: Schrell Uwe M. H. , Rittig Michael G. , Anders Marc , Kiesewetter Franklin , Marschalek Rolf , Koch Uwe H. , Fahlbusch Rudolf
Published: January 2008

Meningiomas, which invade intracranial bone structures and the adjacent connective tissue, are frequently unresectable because of their aggressive and recalcitrant growth behavior. They have a high recurrence rate, and in approximately 10% of these tumors there is an increased risk of malignancy. Significant morbidity and mortality rates associated with recurrent meningiomas demand nonsurgical approaches. To date, adjuvant hormonal treatment has not proven beneficial. The anticancer drug hydroxyurea was therefore tested for its potential use in the treatment of meningiomas.

Early-passaged cell cultures were established from 20 different meningiomas. The addition of 5 X 10−4 and 10−3 M hydroxyurea over a period of 5 to 9 days resulted in a remarkable decrease in cell proliferation and even blocked tumor cell growth when compared with untreated cells. A significant arrest of meningioma cell growth in the S phase of the cell cycle was revealed on DNA flow cytometry.

Electron micrographs of hydroxyurea-treated tumor cells showed ultrastructural features consistent with apoptosis, and light microscopy demonstrated DNA fragmentation by in situ DNA strand break labeling. Short-term treatment of meningioma cell cultures with hydroxyurea for 24 to 48 hours resulted in discrete oligonucleosomal fragments (DNA ladder), another characteristic sign of apoptosis. In addition to the in vitro studies, tissue from five different meningiomas was transplanted into nude mice followed by treatment with 0.5 mg/g body weight hydroxyurea over 15 days. In situ DNA strand break labeling demonstrated DNA fragmentation in distinct regions with different tumor cell densities in all hydroxyurea-treated meningioma transplants.

These data provide evidence that hydroxyurea is a powerful inhibitor of meningioma cell growth, most likely by causing apoptosis in the tumor cells. Thus, hydroxyurea may be a suitable chemotherapeutic agent for the long-term treatment of unresectable or semi- to malignant meningiomas, or for preventing recurrent growth of meningiomas after resection.
Hydroxyurea for treatment of unresectable and recurrent meningiomas. II. Decrease in the size of meningiomas in patients treated with hydroxyurea
Authors: Schrell Uwe M. H. , Rittig Michael G. , Anders Marc , Koch Uwe H. , Marschalek Rolf , Kiesewetter Franklin , Fahlbusch Rudolf
Published: January 2008

In this paper the authors present the first evidence that meningiomas respond to treatment with hydroxyurea. Hydroxyurea was administered as an adjunct chemotherapeutic treatment in patients with recurrent and unresectable meningiomas. Hydroxyurea was used because experimental data demonstrated that it inhibits growth of cultured human meningioma cells and meningioma transplants in nude mice by inducing apoptosis. The authors therefore treated four selected patients with hydroxyurea. All patients had undergone multiple gross resections and all except one received radiotherapy. Three patients with recurrent Grade I meningiomas assessed according to World Health Organization (WHO) guidelines received hydroxyurea because of an increased tumor growth rate, documented by magnetic resonance (MR) imaging, within a 6- or 12-month interval. A fourth patient with a malignant meningioma (WHO Grade III) began a course of treatment with hydroxyurea immediately after his sixth palliative operation without waiting for another relapse to be demonstrated on MR imaging. Because of their location and invasive growth behavior none of the meningiomas could have been removed completely by surgical intervention.

All patients received hydroxyurea at a dosage level of 1000 to 1500 mg/day (approximately 20 mg/kg/day). In a man with a large sphenoid wing meningioma invading the right cavernous sinus and the temporal base, the intracranial tumor mass was reduced by 60% during 6 months of treatment. A woman with a large ball-shaped meningioma of the right sphenoid wing invading the cavernous sinus exhibited a 74% decrease of the initial tumor volume in 10 months of treatment with oral hydroxyurea. Serial MR images obtained monthly revealed that the process of size reduction was continuous and proportionate. The shrinkage of the tumor was accompanied by a complete remission of symptomatic trigeminal neuralgia after 2 months and by improved abducent paresis after 5 months. The third patient had a slowly growing meningioma that exhibited a 15% reduction in mass when reassessed after 5 months of hydroxyurea treatment. The fourth patient with the malignant meningioma in the left cerebellopontine angle has had no recurrence for 24 months. Long-term treatment with hydroxyurea may result in full remission of tumors in meningioma patients.

The preliminary data indicate that hydroxyurea provides true medical treatment in patients with unresectable and recurrent meningiomas, replacing palliative surgery and radiotherapy in the management of this disease.
Primary reconstruction for spinal infections
Authors: Dietze Donald D. , Fessler Richard G. , Jacob R. Patrick
Published: January 2008

Primary reconstruction using bone grafts and instrumentation for spinal infections remains controversial. Between 1991 and 1993, 27 infections of the spinal column were treated at the Department of Neurosurgery of the University of Florida. Of the 27 cases 20 (six cervical, eight thoracic, and six lumbar spine) required surgical debridement and spinal reconstruction to maximize eradication of the infection and maintenance of spinal alignment. All of the cervical and lumbar cases were caused by bacterial infections, and two of eight thoracic cases were caused by tuberculous infections. Spinal arthrodesis was performed in all cases: interbody grafts were used in 18 procedures and posterolateral onlay grafts in 14. Interbody grafts were autologous in 10 cases (six rib and four iliac crest) and homoplastic in eight (six fibular and two humerus). All of the posterolateral onlay grafts were autologous (three rib and 11 iliac crest). Spinal instrumentation was used in 15 cases: four with Caspar plates and 11 with posterior segmental fixation (five hook/rod constructs and six screw/rod constructs). Seventeen of 20 patients achieved improved clinical status postoperatively and 18 of 20 showed radiographic evidence of bone fusion. Antibiotic drugs were administered parenterally for an average of 6 weeks followed by a 3-month course of oral antibiotic medications. Tuberculous infections were treated for 1 year with antibiotic therapy. The average follow-up period was 37 months from surgery and 31 months after completion of treatment with antibiotic drugs. The authors conclude that primary arthrodesis and instrumentation can be performed in acute spinal infections; however, successful management depends on aggressive debridement of infectious foci and prolonged treatment with parenteral antibiotic drugs.
The importance of pial blood supply to the development of peritumoral brain edema in meningiomas
Authors: Bitzer Michael , Wöckel Lars , Luft Andreas R. , Wakhloo Ajay K. , Petersen Dirk , Opitz Holger , Sievert Theo , Ernemann Ulrike , Voigt Karsten
Published: January 2008

The authors studied the pial and dural blood supplies in 74 intracranial meningiomas and quantified their associated peritumoral brain edema (PTBE). The extent and localization of pial blush in relation to the total tumor volume were determined angiographically. The amount of edema and tumor size were calculated using computerized tomography. The edema-tumor volume ratio was defined as Edema Index (EI). There were 49 meningiomas with PTBE; of those tumors, 46 were supplied by pial vessels, and three were supplied exclusively by dural vessels. Tumors without PTBE showed no pial blush. The mean EI in meningiomas with pial blush was significantly larger (EI = 3.0) than in meningiomas without pial supply (EI = 1.1; p < 0.0001). Meningiomas in which 10% of the whole tumor volume was supplied by pial vessels had only a small mean EI of 2.2, whereas tumors with pial blood supply greater than or equal to 20% had a mean EI of 3.3 (p < 0.026). In 69.9% of cases with pial blood supply, major portions of the edema were located adjacent to the tumor region supplied by pial vessels. Edema index differences among tumors of different subgroups, as defined by size or histology, were significantly related to the pial supply in each subset. Thus, pial blood supply may be causative for the development of PTBE in meningiomas.
Hemostasis activation in patients undergoing brain tumor surgery
Authors: Vukovich Thomas Chr. , Gabriel Adelheid , Schaefer Bruno , Veitl Mario , Matula Christian , Spiss Christian K.
Published: January 2008

Patients undergoing brain tumor surgery are at high risk for the occurrence of a thromboembolic event. To identify a laboratory marker suitable for risk estimation the authors studied the perioperative time pattern of routine coagulation parameters and the specific hemostasis activation marker D-dimer in 28 consecutive patients at high risk (11 patients with glioma and eight patients with menigioma) and low risk (9 patients with metastases) for thromboembolism, as previously reported. As is typical during major surgery, most of the routine parameters declined, probably because of hemodilution, and recovered postoperatively to values higher than baseline, probably because of an acute-phase reaction. On Days 2 and 7 after surgery no difference in the routine parameters was recorded between patients at high (meningioma and glioma) and low risk (metastases). The level of D-dimer was elevated at baseline in patients with metastases, indicating a hemostatic hyperactivity that is usual in cancer patients. During surgery a marked increase in D-dimer levels occurred in patients with meningioma and glioma (pre- and postoperative median 90/2000 and 100/1020 ng/ml, respectively), but the increase was less pronounced in patients with metastases (320/660 ng/ml). Postoperatively, D-dimer declined in patients with metastases to lower levels than preoperatively (Day 7, 270 ng/ml); in patients with meningioma or glioma, however, D-dimer levels remained elevated until Day 7 (450 and 200 ng/ml). These results indicate that levels of D-dimer correlate with the reported high risk for thromboembolism in patients with meningioma and glioma, and D-dimer should be evaluated for its use in estimating individual risk and the efficiency of its use in the control of prophylactic treatment.
Current status of radiation therapy and radiosurgery in the treatment of intracranial meningiomas
Authors: Engelhard Herbert H.
Published: January 2008

Complete surgical removal, including resection of involved bone and dura, is curative of intracranial meningiomas in approximately 90% of cases. However, complete removal may entail unwarranted risk if the tumor involves or is adjacent to critical vascular or neural structures. In addition, it is possible for fragments of tumor to “evade” resection, even with the use of meticulous microsurgical technique. Because of this, clinicians may be faced with the decision of whether to offer or recommend radiation therapy or radiosurgery to a patient with a residual or recurrent meningioma. For many years, it has been recommended that external-beam radiation therapy be considered in the treatment of incompletely resected or malignant meningiomas. More recently, the role of radiosurgery as adjuvant or even primary therapy for meningiomas has attracted considerable attention. This article presents a review of the literature on postoperative radiotherapy of intracranial meningiomas.
Brain tissue acid-base changes during ischemia
Authors: Hoffman William E. , Charbel Fady T. , Edelman Guy , Ausman James I.
Published: January 2008

It is likely that brain tissue acidosis during ischemia is associated with neuronal injury. The authors measured brain extracellular H+, PCO2 and HCO3- concentrations during an ischemic event produced by temporary occlusion of the middle or anterior cerebral arterial distributions, with a 10-minute recovery period. Patients who were to undergo craniotomy for cerebrovascular surgery were recruited for the study. A probe that measures PCO2, pH, and temperature was inserted into tissue at risk for ischemia during temporary arterial occlusion. As a control for this treatment, PaCO2 was increased 10 mm Hg in five patients over a 10-minute period. Under baseline conditions, there was no difference in arterial blood pressure, blood gas levels, or brain temperature between patients who underwent temporary arterial occlusion or those in whom hypercapnia was induced. In patients in whom hypercapnia was induced, H+, PCO2, and HCO3- concentrations increased and all values returned to baseline levels within 10 minutes. In 10 patients who underwent a median 9-minute arterial occlusion, transient ischemia was seen with an increase in tissue H+ and PCO2 levels of 100% and 60%, respectively, and a 20% decrease in HCO3-levels. After a 10-minute postischemic recovery, only PCO2 had returned to baseline levels. These results are consistent with a rapid equilibration of lactic acidosis across the cell membrane during ischemia which decreases HCO3- concentration. After ischemia, extracellular acidosis may be prolonged because of the extrusion of H+ from the cell by membrane ion exchange.
Complications in the treatment of carpal tunnel syndrome
Authors: Henkin Philip , Friedman Allan H.
Published: January 2008

Complications may result from every facet of the management of carpal tunnel syndrome. The authors review the common errors in diagnosis, nonoperative management, and operative treatment, with emphasis on prevention and resolution of complications. In general, surgeons can minimize complications by taking a thorough patient history, performing a comprehensive physical examination, and possessing a precise knowledge of the appropriate anatomy. Endoscopic techniques appear to offer some advantage over conventional open techniques with regard to the patient's postoperative incision pain, preservation of grip strength, and time to return to work; however, these advantages may be potentially negated by the risk of injury to neurovascular structures and tendons.
Microsurgical carpal tunnel release
Authors: Shapiro Scott
Published: January 2008

The author reports on a series of 482 patients who underwent primary carpal tunnel release (CTR) surgery beginning in 1987. Two hundred twenty-five patients underwent CTR in the right hand, 169 patients underwent CTR in the left hand, and 88 patients underwent bilateral CTR surgery, for a total of 570 hands. These surgeries were performed on an outpatient basis. After application of a local anesthetic, a microsurgical technique using a 2-cm longitudinal incision that did not cross the wrist flexion crease was accomplished. In five patients the recurrent thenar branch exited through the middle or ulnar portion of the ligament and this branch was preserved in all five. Perioperative complications included stitch abscesses in nine hands (2%), which were managed on an outpatient basis; deep wound infections occurred in three hands (0.5%) and these patients were admitted for intravenous antibiotic administration and wound care. One steroid-dependent patient suffered wound dehiscence due to a fall and the wound was primarily repaired. One patient required a second minor procedure to remove a retained suture. Two patients developed “trigger finger” 6 months postoperatively. The mean time until return to work for those patients not receiving Workers' Compensation was 3 weeks and for those receiving Workers' Compensation it was 6.5 weeks. Complete disappearance of painful dysesthesias occurred in 431 (89%) of 482 patients. Marked improvement occurred in another 33 (7%) patients, yielding an overall improvement rate of 96%. Motor improvement was noted in 438 (96%) of 454 patients with preoperative motor weakness. Bilateral symptoms resolved on the contralateral side following unilateral surgery in seven patients. Fifteen patients (12 of whom were receiving Workers' Compensation) experienced persistent dysesthesias and/or incision pain and did not return to work. An additional eight procedures were performed in patients who had previously undergone surgery at another institution; four showed no evidence of their transverse carpal ligament being sectioned. Five of the eight patients undergoing reexploration noted postoperative improvement in their symptoms. Finally, 14 (3%) patients presented 1 to 5 years postsurgery with thenar/hypothenar pain. These patients have responded to local steroid injections and are being followed by a hand surgeon.

The reimbursement of the surgeon's fee is $253.00 from Medicaid, $360.00 from Medicare, and $560.00 from preferred provider insurance. The mean total time in the outpatient operating room is 35 to 40 minutes. The outcome and time to return to work are equal, if not superior, to those reported for endoscopic CTR surgery. Microsurgical CTR is thought to be safer and probably more cost-effective.
Acquired lumbar stenosis: topic review and a case series
Authors: Jane John A. , diPierro Charles G. , Helm Gregory A. , Shaffrey Christopher I. , Jane John A.
Published: January 2008

Stenosis of the central and lateral lumbar vertebral canal can be congenital or acquired; the latter is most often caused by a degenerative process. The associated neurogenic claudication and/or radiculopathic symptom complexes are thought to result from compression of the cauda equina and lumbosacral nerve roots by hypertrophy of or encroachment by any combination of the following: canal walls, ligamenta flava, intervertebral discs, posterior longitudinal ligament, or epidural fat.

The authors' technique for the treatment of lumbar stenosis involves extensive unilateral decompression with undercutting of the spinous process and obviates the need for instrumentation by using a contralateral autologous bone fusion. The results in a series of 29 patients in whom the procedure was performed suggest that this decompression method safely and successfully treats not only the radicular symptoms caused by lateral stenosis but also the neurogenic claudication symptoms associated with central stenosis. In addition, the procedure can preserve spinal stability without instrumentation by using contralateral autologous bone fusion along the laminae and spinous processes.
Selective extradural anterior clinoidectomy for supra- and parasellar processes
Authors: Yonekawa Yasuhiro , Ogata Nobuyoshi , Imhof Hans-Georg , Olivecrona Magnus , Strommer Kevin , Kwak Tae Eon , Roth Peter , Groscurth Peter
Published: January 2008

Removal of the anterior clinoid process (ACP) facilitates radical removal of tumors or radical neck clipping of aneurysms in the supra- and parasellar regions by providing a wide operative exposure of the internal carotid artery (ICA) and the optic nerve and by reducing the need for brain retraction.

Over a period of 3 years, anterior clinoidectomy was performed in 40 patients, 30 of whom harbored aneurysms (18 of the ICA and 13 of the basilar artery [one patient had two aneurysms]) and 10 of whom had tumors (four large pituitary tumors, four craniopharyngiomas, and two sphenoid ridge meningiomas). The ACP was removed extradurally in 31 cases and intradurally in nine cases.

Extradural clinoidectomy was performed in all cases of pituitary adenoma and craniopharyngioma and in most cases of basilar artery aneurysm. Intradural clinoidectomy was performed in two cases of ICA-ophthalmic artery aneurysm, two cases of ICA-posterior communicating artery aneurysm, two cases of ICA cavernous aneurysm, one case of basilar artery aneurysm, and two cases of sphenoid ridge meningioma. The outcome was satisfactory in all patients, except for one patient who underwent clipping of a basilar tip aneurysm and suffered a thalamic and midbrain infarction. Three patients who underwent extradural clinoidectomy suffered a postoperative diminution of visual acuity or a visual field defect on the side of the clinoidectomy. These deficits may have been caused either by drilling of the ACP or by other operative manipulation of the optic nerve. Cerebrospinal fluid rhinorrhea, which required reoperation, occurred in one patient.

The authors' experience suggests that the extradural technique of ACP removal is easier and less time consuming than the intradural one and provides better operative exposure. It can be used routinely in treating lesions in the supra- and parasellar regions.
Indications for fusion following decompression for lumbar spinal stenosis
Authors: Fox Mark W. , Onofrio Burton M.
Published: January 2008

Degenerative lumbar spinal stenosis is a common condition affecting middle-aged and elderly people. Significant controversy exists concerning the appropriate indications for fusion following decompressive surgery. The purpose of this report is to compare the clinical outcomes of patients who were and were not treated with fusion following decompressive laminectomy for spinal stenosis and to identify whether fusion was beneficial. The authors conclude that patients in whom concomitant fusion procedures were performed fared better than patients who were treated by means of decompression alone when evidence of radiological instability existed preoperatively.
Lumbar stenosis: indications for fusion with and without instrumentation
Authors: Detwiler Paul W. , Marciano Frederick F. , Porter Randall W. , Sonntag Volker K. H.
Published: January 2008

Although the efficacy of posterior decompression for symptomatic lumbar stenosis that is recalcitrant to conservative therapy is well proven, uniform agreement on the need for simultaneous arthrodesis is lacking. The variability in the rate of lumbar fusion with and without instrumentation has been attributed to a number of factors: advances in surgical technique; rapid development of instrumentation; radiographic advances in the diagnosis of disease entities of the lumbar spine; evolution in our understanding of bone healing; improved pre- and postoperative care; aggressive rehabilitation; patient compensation; hospital and surgeon reimbursement; better education of residents, fellows, and practicing neurosurgeons; and, most important, the lack of clear indications based on defined diagnostic categories. Based on review of the literature and their experience at the Barrow Neurological Institute, the authors have attempted to define indications for lumbar fusion with or without instrumentation based on defined diagnostic categories. Clear indications for fusion include trauma, tumor, or infection with two- or three-column injury, iatrogenic instability, and isthmic spondylolisthesis. Relative indications for fusion include degenerative spondylolisthesis, radiographically proven dynamic instability with pain or neurological findings, adult scoliosis, and mechanical back pain. Fusion is rarely indicated with discectomy, abnormal radiographs without appropriate findings (such as degenerative disc disease), facet joint syndrome, failed back surgery, or stable spinal stenosis.
Total sacrectomy and Galveston L-rod reconstruction for malignant neoplasms
Authors: Gokaslan Ziya L. , Romsdahl Marvin M. , Kroll Stephen S. , Walsh Garrett L. , Gillis Theresa A. , Wildrick David M. , Leavens Milam E.
Published: January 2008

Although radical resection is the best treatment for malignant sacral tumors, total sacrectomy for such tumors has been performed in only a few instances. Total sacral resection requires reconstruction of the pelvic ring plus establishment of a bilateral union between the lumbar spine and iliac bone. This technique is illustrated in two patients harboring large, painful, sacral giant-cell tumors that were unresponsive to prior treatment. These patients were treated with complete en bloc resection of the sacrum and complex iliolumbar reconstruction/stabilization and fusion. Surgery was performed in two stages, the first consisting of a midline celiotomy, dissection of visceral/neural structures, and ligation of internal iliac vessels, followed by an anterior L5-S1 discectomy. The second stage consisted of mobilization of an inferiorly based myocutaneous rectus abdominis pedicle flap for wound closure, followed by an L-5 laminectomy, bilateral L-5 foraminotomy, ligation of the thecal sac, division of sacral nerve roots, and transection of the ilia lateral to the tumor and sacroiliac joints. Placement of the instrumentation required segmental fixation of the lumbar spine from L-3 down by means of pedicle screws and the establishment of a bilateral liaison between the lumbar spine and the ilia by using the Galveston L-rod technique. The pelvic ring was then reestablished by means of a threaded rod connecting left and right ilia. Both autologous (posterior iliac crest) and allograft bone were used for fusion, and a tibial allograft strut was placed between the remaining ilia. The patients were immobilized for 8 weeks postoperatively and underwent progressive rehabilitation. At the 1-year follow-up review, one patient could walk unassisted, and the other ambulated independently using a cane. Both patients controlled bowel function satisfactorily with laxatives and diet and could maintain continence but required self-catheterization for bladder emptying. The authors conclude that in selected patients, total sacrectomy represents an acceptable surgical procedure that can offer not only effective local pain control, but also a potential cure, while preserving satisfactory ambulatory capacity and neurological function.
Cervical cord neurapraxia: classification, pathomechanics, morbidity, and management guidelines
Authors: Torg Joseph S. , Corcoran Thomas A. , Thibault Lawrence E. , Pavlov Helene , Sennett Brian J. , Naranja R. John , Priano Steven
Published: January 2008

One hundred ten cases of the transient neurological phenomenon, cervical cord neurapraxia (CCN), are presented. The authors established a classification system for CCN, developed a new computerized measurement technique for magnetic resonance (MR) imaging, investigated the relationship of the cervical cord to the canal, and analyzed clinical, x-ray, and MR data. One hundred nine males and one female were included in the study; the average age of the participants was 21 years (range 13-33 years). All episodes occurred during sports participation; 87% occurred while the patient was playing football. Follow-up review lasting an average of 3.3 years was available for 105 patients (95%).

Narrowing of the sagittal diameter of the cervical canal in the adult spine was confirmed to be a causative factor. Cervical cord neurapraxia was not associated with permanent neurological injury and no permanent morbidity occurred in patients who returned to contact activities. Of the patients returning to contact activities, 35 (56%) experienced a recurrent episode. The risk of recurrence was increased with smaller spinal canal/vertebral body ratio (p < 0.05), smaller disc-level canal diameter (p < 0.05), and less space available for the cord (p < 0.05). There was no correlation between either the classification of the CCN episode or the disease noted on MR imaging and x-ray films and the risk of recurrence.

The authors conclude that: 1) CCN is a transient neurological phenomenon and individuals with uncomplicated CCN may be permitted to return to their previous activity without an increased risk of permanent neurological injury; 2) congenital or degenerative narrowing of the sagittal diameter of the cervical canal is a causative factor; 3) the overall recurrence rate after return to play is 56%; and 4) the risk of recurrence is strongly and inversely correlated with sagittal canal diameter and it is useful in the prediction of future episodes of CCN (p < 0.001). These data will enable the physician to counsel individuals regarding a predicted risk of recurrence based on canal measurements.
Source and cause of endothelin-1 release to cerebrospinal fluid after subarachnoid hemorrhage
Authors: Pluta Ryszard M. , Boock Robert J. , Afshar John K. , Clouse Kathleen , Bacic Mima , Ehrenreich Hannelore , Oldfield Edward H.
Published: January 2008

Despite years of research, delayed cerebral vasospasm remains a serious complication of subarachnoid hemorrhage (SAH). Recently, it has been proposed that endothelin-1 (ET-1) mediates vasospasm. The authors examined this hypothesis in a series of experiments. In a primate model of SAH, serial ET-1 levels were measured in samples from the perivascular space by using a microdialysis technique and in cerebrospinal fluid (CSF) and plasma during the development and resolution of delayed vasospasm. To determine whether elevated ET-1 production was a direct cause of vasospasm or acted secondary to ischemia, the authors also measured ET-1 levels in plasma and CSF after transient cerebral ischemia. To elucidate the source of ET-1, they measured its production in cultures of endothelial cells and astrocytes exposed to oxyhemoglobin (10 μM), methemoglobin (10 μM), or hypoxia (11% oxygen).

There was no correlation between the perivascular levels of ET-1 and the development of vasospasm or its resolution. Cerebrospinal fluid and plasma levels of ET-1 were not affected by vasospasm (CSF ET-1 levels were 9.3 ± 2.2 pg/ml and ET-1 plasma levels were 1.2 ± 0.6 pg/ml) before SAH and remained unchanged when vasospasm developed (7.1 ± 1.7 pg/ml in CSF and 2.7 ± 1.5 pg/ml in plasma). Transient cerebral ischemia evoked an increase of ET-1 levels in CSF (1 ± 0.4 pg/ml at the occlusion vs. 3.1 ± 0.6 pg/ml 4 hours after reperfusion; p < 0.05), which returned to normal (0.7 ± 0.3 pg/ml) after 24 hours. Endothelial cells and astrocytes in culture showed inhibition of ET-1 production 6 hours after exposure to hemoglobins. Hypoxia inhibited ET-1 release by endothelial cells at 24 hours (6.4 ± 0.8 pg/ml vs. 0.1 ± 0.1 pg/ml, control vs. hypoxic endothelial cells; p < 0.05) and at 48 hours (6.4 ± 0.6 pg/ml vs. 0 ± 0.1 pg/ml, control vs. hypoxic endothelial cells; p < 0.05), but in astrocytes hypoxia induced an increase of ET-1 at 6 hours (1.5 ± 0.6 vs. 6.4 ± 1.1 pg/ml, control vs. hypoxic astrocytes; p < 0.05).

Endothelin-1 is released from astrocytes, but not endothelial cells, during hypoxia and is released from the brain after transient ischemia. There is no relationship between ET-1 and vasospasm in vivo or between ET-1 and oxyhemoglobin, a putative agent of vasospasm, in vitro. The increase in ET-1 levels in CSF after SAH from a ruptured intracranial aneurysm appears to be the result of cerebral ischemia rather than reflecting the cause of cerebral vasospasm.
Comparison of balloon angioplasty and papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage
Authors: Elliott J. Paul , Newell David W. , Lam Derek J. , Eskridge Joseph M. , Douville Colleen M. , LeRoux Peter D. , Lewis David H. , Mayberg Marc R. , Grady M. Sean , Winn H. Richard
Published: January 2008

The authors used daily transcranial Doppler (TCD) evaluation to test the hypothesis that balloon angioplasty is superior to papaverine infusion for the treatment of proximal anterior circulation arterial vasospasm following subarachnoid hemorrhage (SAH). Between 1989 and 1995, 125 vasospastic distal internal carotid artery or proximal middle cerebral artery vessel segments were treated in 52 patients. Blood flow velocities of the involved vessels were assessed using TCD monitoring in relation to the day of treatment with balloon angioplasty or papaverine infusion. Balloon angioplasty and papavarine infusion cohorts were compared based on mean pretreatment velocity and mean posttreatment velocity at 24 and 48 hours using the one-tailed, paired-samples t-test. Balloon angioplasty alone was performed in 101 vessel segments (81%) in 39 patients (75%), whereas papaverine infusion alone was used in 24 vessel segments (19%) in 13 patients (25%). Although repeated treatment following balloon angioplasty was needed in only one vessel segment, repeated treatment following papaverine infusion was required in 10 vessel segments (42%) in six patients because of recurrent vasospasm (p < 0.001). Seven vessel segments (29%) with recurrent spasm following papaverine infusion were treated with balloon angioplasty. Although vessel segments treated with papaverine demonstrated a 20% mean decrease in blood flow velocity (p < 0.009) on posttreatment Day 1, velocities were not significantly lower than pretreatment levels by posttreatment Day 2 (p = 0.133). Balloon angioplasty resulted in a 45% mean decrease in velocity to a normal level following treatment (p < 0.001), which was sustained. The authors conclude that balloon angioplasty is superior to papaverine infusion for the permanent treatment of proximal anterior circulation vasospasm following aneurysmal SAH.
Adenosine triphosphate and hemoglobin in vasospastic monkeys
Authors: Macdonald R. Loch , Weir Bryce , Zhang John , Marton Linda S. , Sajdak Michael , Johns Lydia M.
Published: January 2008

Adenosine triphosphate (ATP) is a vasoactive compound found in high levels inside erythrocytes that may contribute to vasospasm occurring after subarachnoid hemorrhage (SAH). This study was instituted to test whether ATP causes vasospasm in a monkey model.

Thirty-two monkeys were randomized to four groups of eight monkeys each to undergo cerebral angiography at baseline (Day 0) and then at Day 7 after subarachnoid placement of: 1) agarose, 2) ATP in agarose, 3) autologous hemolysate in agarose, or 4) purified human hemoglobin A0 in agarose. Vasospasm was assessed by comparison of Day 0 and Day 7 angiograms between and within groups and by pathological examination of a subset of perfusion-fixed monkeys. Levels of adenine nucleotides were measured on Day 7 in subarachnoid agarose by high-pressure liquid chromatography.

There was significant vasospasm of the right middle cerebral artery in groups given ATP (-28 ± 7% reduction, paired t-test, p < 0.05), hemolysate (-23 ± 7%, p < 0.05), or pure hemoglobin (-15 ± 2%, p < 0.005). Analysis of variance revealed no significant differences between groups in diameters of cerebral arteries on Day 7. Pathological examination showed mild inflammation in the subarachnoid spaces of animals exposed to hemolysate or hemoglobin and less inflammation in those given ATP or agarose. There were no pathological changes in the cerebral arteries of animals in any group. Most of the ATP diffused out of the subarachnoid agarose by Day 7, and levels of adenine nucleotides in subarachnoid agarose were higher on Day 7 in animals exposed to hemoglobin or hemolysate.

It is concluded that ATP could contribute to vasospasm occurring after SAH but that further investigations are necessary to determine if levels of ATP adjacent to vasospastic arteries are sufficient to contribute to vasospasm. In addition, no observation was made of severe vasospasm with histopathological changes in the arteries equivalent to that produced by whole blood clot in the subarachnoid space of monkeys. It should be determined whether this is because a single compound, such as ATP or hemoglobin, causes vasospasm, but that placing the compound in agarose alters its delivery and decreases the amount of vasospasm produced, or whether vasospasm is a more complex, multifactorial process.
Generation of the catalytic fragment of protein kinase C alpha in vasospastic canine basilar artery
Authors: Sato Motohiko , Tani Eiichi , Matsumoto Tsuyoshi , Fujikawa Hirokazu , Imajoh-Ohmi Shinobu
Published: January 2008

In previous studies of topical application of calphostin C, a specific inhibitor of the regulatory domain of protein kinase C (PKC), and calpeptin, a selective inhibitor of calpain, to spastic canine basilar artery (BA) researchers have suggested that the catalytic fragment of PKC (known as PKM) is probably formed by a limited proteolysis of continuously activated μ-calpain, but there has been no direct evidence for PKM formation in vasospasm. The present immunoblot study with anti-PKC-alpha antibody shows a significant decrease in cytosolic 80-kD PKC-alpha and a concomitantly significant increase in membrane PKC-alpha in the spastic canine BA. In addition, an immunoblot study in which cleavage site-directed antibodies were used demonstrated a significant increase in immunoreactive 45-kD PKM. The changes in membrane PKC-alpha and PKM were enhanced with the lapse of time after subarachnoid hemorrhage. The cleavage site-directed antibodies distinguish the proteolyzed from the unproteolyzed forms of PKC for in situ analyses of enzyme regulation mediated by proteolysis. The data indicate that PKC-alpha in spastic canine BA is translocated to the cell membrane, where PKC-alpha is rapidly cleaved into PKM as a result of proteolysis of the isozyme by μ-calpain but not by m-calpain. The authors hypothesize that μ-calpain is continuously activated in spastic canine BA and produces PKM by limited proteolysis of PKC-alpha.
Attenuation of cerebral vasospasm by systemic administration of an endothelin-A receptor antagonist, TBC 11251, in a rabbit model of subarachnoid hemorrhage
Authors: Wanebo John E. , Louis Hunter G. , Arthur Adam S. , Zhou Jie , Kassell Neal F. , Lee Kevin S. , Helm Gregory A.
Published: January 2008

Cerebral vasospasm is a major complication of subarachnoid hemorrhage (SAH) after the rupture of an intracranial aneurysm. Although the cause of cerebral vasospasm has not been fully established, several lines of evidence suggest that the vasoconstrictor peptide endothelin (ET) may play a crucial role. In the present study the potential of TBC 11251 (TBC), a newly developed ETA receptor antagonist, to prevent and/or reverse cerebral vasospasm was examined in a well-established rabbit model of SAH.

Sixty-five New Zealand White rabbits were assigned to one of six groups. Experimental SAH was induced in rabbits comprising five of the groups by injecting autologous arterial blood into the cisterna magna. The treatment groups were as follows: 1) control (no SAH); 2) SAH only; 3) SAH + placebo at 24 and 36 hours (24/36); 4) SAH + TBC (24/36); 5) SAH + placebo twice daily (BID); and 6) SAH + TBC BID. All drug-treated animals received an intravenous dosage of 5 mg/kg TBC. After 48 hours, the animals were killed by intracardiac perfusion with fixative. The brainstems were removed and the basilar arteries (BAs) were prepared for histological examination. The cross-sectional area of each BA was measured using computer-assisted videomicroscopy by an investigator blind to the group from which it came. A one-way analysis of variance and paired group mean comparisons with the post-hoc Fisher least significant difference test were used for analysis of BA diameters and physiological parameters.

The model provided reliable vasospasm, with the mean BA cross-sectional area constricting from 0.388 mm2 in the control group to 0.106 mm2 (27.4% of control) in the SAH only group. Treatment with TBC (24/36) after SAH (reversal protocol) produced a mean BA area of 0.175 mm2 (44.2% of control) which, although larger than the placebo group value of 0.135 mm2 (39.9% of control), was not statistically significant. However, treatment with TBC BID (prevention protocol) produced a mean BA area of 0.303 mm2 (78.1% of control) compared with the placebo BID value of 0.134 mm2 (34.6% of control); this effect was statistically significant (p < 0.01). There were no side effects noted and no differences in the mean arterial pressures between drug and placebo groups.

These findings demonstrate that systemic administration of the ETA receptor antagonist TBC significantly attenuates cerebral vasospasm after SAH when given as a preventative therapy, and they provide additional support for the role of ET in the establishment of vasospasm.
Multiple appearing and vanishing aneurysms: primary angiitis of the central nervous system
Authors: Nishikawa Misao , Sakamoto Hiroaki , Katsuyama Junsuke , Hakuba Akira , Nishimura Shuro
Published: January 2008

The authors present the case of a patient with ischemic episodes and recurrent intracerebral hemorrhages probably caused by primary angiitis of the central nervous system (CNS). An initial angiogram revealed multiple cerebral artery aneurysms as well as vascular wall irregularity; a second angiogram obtained 2 years later, however, did not demonstrate the previous aneurysms but instead showed new ones together with stenosis. Based on the histopathological findings and clinical course in this case, the multiple aneurysms appear to have been induced by vascular wall fragility and subsequent self-repair resulting from primary angiitis of the CNS. The authors present the histological and clinical characteristics of this unusual case of granulomatous, necrotizing CNS vasculitis.