bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumoral Calcium Pyrophosphate Dihydrate Deposition Disease of the Ligamentum Flavum
Authors: Muthukumar Natarajan , Karuppaswamy Usharani
Published: August 2004

OBJECTIVE

Calcium pyrophosphate dihydrate (CPPD) deposition disease (CPPDD), also known as pseudogout, is rarely known to affect the spine. The purpose of this article is to report our experience with six cases involving massive focal deposition of CPPD crystals in the ligamentum flavum.

METHODS

Between January 1998 and June 2002, we treated six patients with CPPDD involving the ligamentum flavum of the cervical and thoracic spine. Their ages ranged from 45 to 70 years. There were five female patients and one male patient. The cervical spine was involved in two cases and the thoracic spine in four. All except one patient presented with an insidious onset of myelopathy. The remaining patient presented with paraplegia after trauma. None of the patients exhibited any systemic features of CPPDD or other metabolic conditions that can lead to CPPD deposition. Plain x-rays often yielded inconclusive results. Computed tomography and magnetic resonance imaging were useful in confirming the diagnoses. Decompressive laminectomy, with removal of the ossified ligamenta flava, was performed for all patients. Polarized-light microscopic examinations of the excised ligamenta flava revealed the characteristic rod-shaped, birefringent crystals.

RESULTS

Five of the six patients experienced significant improvements in their myelopathic symptoms after surgery. The remaining patient experienced improvements in sensations but no appreciable improvement in motor power. During the follow-up periods, which ranged from 7 months to 3 years, none of the patients presented with a recurrence of CPPD crystal deposition at the previously treated level. However, one patient who exhibited improvement after surgery presented 2 years later with a recurrence of myelopathic features attributable to ossification of the ligamentum flavum at a new level.

CONCLUSION

Tumoral CPPDD of the ligamentum flavum is rare. It commonly occurs among middle-age or elderly female patients and presents with progressive myelopathy. Computed tomography and magnetic resonance imaging are complementary in the diagnosis of this condition. Surgery, if performed early, leads to good improvement. However, long-term follow-up monitoring of these patients is necessary, because surgery provides only symptomatic relief and does not treat the underlying disease. With the increasing availability of magnetic resonance imaging, ossification of the ligamentum flavum is being more frequently recognized. In every case of ossified ligamentum flavum, the excised specimen should be examined with polarized-light microscopy. We think that this simple, inexpensive method will lead to the recognition of more cases of spinal CPPDD.
Quality of Reporting in Evaluations of Surgical Treatment of Trigeminal Neuralgia: Recommendations for Future Reports
Authors: Zakrzewska Joanna M. , Lopez Benjamin C.
Published: August 2004

OBJECTIVE

There are numerous reports on the surgical treatment of trigeminal neuralgia, but the studies do not use uniform outcome measures, which makes it difficult for patients and clinicians to determine which treatment may be most appropriate. The objectives of this study were to set quality criteria and standards for outcome reporting for the surgical treatment of trigeminal neuralgia (on the basis of international expert opinion), to identify and assess all studies of the surgical treatment of trigeminal neuralgia and evaluate the studies against those criteria, and to provide recommendations for submitting reports on the outcomes of surgical treatment of trigeminal neuralgia.

METHODS

The types of data that 11 neurosurgeons and 2 neurologists considered essential for articles reporting the outcomes of surgical treatment of trigeminal neuralgia were the quality criteria used by the two authors. Standards were established in terms of the minimal number and type of criteria that studies should meet to allow their use in a potential systematic review of pain outcomes of surgical treatment of trigeminal neuralgia. Studies were identified in MEDLINE searches and from other sources and were independently scored against those criteria by the two authors. The reproducibility of the method was checked with assessments of inter- and intra-rater reliability. A checklist for the reporting of studies was formulated.

RESULTS

A total of 281 studies were identified, of which 222 were scored. Seventy-one (32%) of the studies reached the minimal set standards, but only 28 (13%) could be used for assessment of pain outcomes, because they included actuarial analyses. There was good agreement between the two authors in the scoring of the studies, although some criteria required stricter definitions. A checklist for the reporting of future studies on the surgical treatment of trigeminal neuralgia was proposed.

CONCLUSION

When assessed against the proposed criteria and standards, the quality of reporting was generally poor. The methods for reporting surgical outcomes for trigeminal neuralgia were not uniform; therefore, the comparability of results and techniques was low. Data should be collected and reported in a standardized way. A protocol for data collection and reporting on the surgical treatment of trigeminal neuralgia has been proposed. Further research is needed to evaluate this tool.
An Alternative Extradural Exposure to the Anterior Clinoid Process: The Superior Orbital Fissure as a Surgical Corridor
Authors: Coscarella Ernesto , Başkaya Mustafa K. , Morcos Jacques J.
Published: August 2004

OBJECTIVE

Dolenc has pioneered the extradural approach to the anterior clinoid process (ACP) in approaching the cavernous sinus, clinoidal space, and orbital apex. A key step is the division of the frontotemporal dural fold (FTDF). Less experienced surgeons may not be as versatile in their three-dimensional understanding of the superior orbital fissure and thus may risk injury to its contents. Through our cadaveric and subsequent clinical experience, we have devised a modification of the approach that permits safer handling of the contents of the superior orbital fissure.

METHODS

In five consecutive injected cadaveric heads (10 sides), we performed on one side a traditional extradural exposure of the ACP. On the other side, we performed our alternative dissection. Instead of exposing the ACP from medial to lateral and dividing the frontotemporal dural fold along the assumed path of safety, we followed the edge of the lesser wing from lateral to medial, uncovered the superior orbital fissure, and peeled the outer layer of the cavernous sinus medial to the foramen rotundum along the greater wing, thus uncovering the inferolateral surface of the ACP. This allowed dural division under full visualization.

RESULTS

The alternative method proved easier and more reliable in every case. We applied this technical modification in seven patients with no complications. Specifically, there was no injury to the oculomotor, lacrimal, frontal, or trigeminal nerves or branches. We present detailed anatomic expositions of the injected specimens.

CONCLUSION

This technical modification of the extradural approach of Dolenc is a simple, safe, and valuable adjunct to the exposure of the ACP. We recommend its use particularly by relatively inexperienced surgeons.
Tentorial Dural Arteriovenous Fistula Presenting with Various Visual Symptoms Related to Anterior and Posterior Visual Pathway Dysfunction: Case Report
Authors: Benndorf Goetz , Schmidt Stefanie , Sollmann Wolf-Peter , Kroppenstedt Stefan-Nikolaus
Published: August 2004

OBJECTIVE AND IMPORTANCE

Dural arteriovenous fistulae (DAVFs) not directly shunting into the cavernous sinus are an infrequent cause of visual dysfunction. An unusual case of a tentorial DAVF associated with visual symptoms related to dysfunction of the anterior and posterior visual pathway is presented.

CLINICAL PRESENTATION

A 38-year-old woman with a history of long-standing bilateral proptosis experienced a sudden onset of headache and visual disturbances. Ocular examination revealed bilateral episcleral and retinal venous congestion, optic disc paleness, right superior homonymous quadrantanopsia in both eyes, and concentric narrowing of the visual field of the right eye. Angiography revealed a DAVF supplied by a falx branch arising from the left vertebral artery and both middle meningeal arteries, which drained directly into the markedly dilated vein of Galen via the basal vein of Rosenthal and the cavernous sinus into both superior ophthalmic veins.

INTERVENTION

Endovascular treatment was performed in two consecutive sessions by transarterial embolization with n-butylcyanoacrylate, which resulted in occlusion of the fistula and complete clinical cure, confirmed at the 6-month follow-up examination.

CONCLUSION

Various neuro-ophthalmological findings may be caused by an arteriovenous lesion remote from the optic organ as a result of rerouting of venous drainage compromising the visual pathway at different locations. Transarterial embolization of a DAVF may result in complete cure if advantageous arterial anatomy allows for flow control and occlusion of the fistulous connection with liquid adhesives.
Melanocytic Colonization of a Meningothelial Meningioma: Histopathological and Ultrastructural Findings with Immunohistochemical and Genetic Correlation: Case Report
Authors: Nestor Scott L. , Perry Arie , Kurtkaya Ozlem , Abell-Aleff Patrice , Rosemblat Aldo M. , Burger Peter C. , Scheithauer Bernd W.
Published: August 2004

OBJECTIVE AND IMPORTANCE

Melanocytic colonization of nonpigmented extracranial tumors has been reported in adenocarcinomas, squamous cell carcinomas, skin appendage tumors, and dermatofibrosarcoma protuberans. To our knowledge, melanocytic colonization of a meningioma has not previously been described.

CLINICAL PRESENTATION

We report an unusual case of a 70-year-old African-American woman who presented with a large frontoparietal meningioma that extended through the calvarium.

INTERVENTION

Craniotomy with gross total resection of the tumor was performed. Histochemistry, immunocytochemistry, ultrastructural analysis, and molecular genetic study via fluorescence in situ hybridization confirmed melanocytic colonization of a meningothelial meningioma.

CONCLUSION

With the inclusion of meningothelial meningioma, the spectrum of tumors affected by melanocytic colonization continues to expand.
Cervical Cord Compression with Myelopathy Caused by Bilateral Persistence of the First Intersegmental Arteries: Case Report
Authors: Takahashi Toshiyuki , Tominaga Teiji , Hassan Tamer , Yoshimoto Takashi
Published: August 2004

OBJECTIVE AND IMPORTANCE

Cervical myelopathy induced by vascular compression is rare. We report a case caused by bilateral persistence of the first intersegmental arteries (a vertebral artery anomaly). Myelopathy was successfully treated with vascular decompression.

CLINICAL PRESENTATION

A 66-year-old woman presented with gradually worsening paroxysmal neck and arm pain. Magnetic resonance imaging and angiography demonstrated anomalous intradural courses of both vertebral arteries, compressing the dorsal aspect of the cervical spinal cord.

INTERVENTION

Microvascular decompression was performed with transposition of the arteries, followed by anchoring of the arteries to the dorsolateral dura mater with Gore-Tex bands (W.L. Gore & Associates, Inc., Flagstaff, AZ).

CONCLUSION

The pain disappeared promptly after surgery. Surgical decompression, with anchoring of an anomalous vertebral artery to the dura, can relieve pain and other symptoms resulting from vascular cord compression.
Shunt Malfunction Caused by Mischievous Twisting of the Valve by the Patient: Case Report
Authors: Nabika Shinya , Oki Shuichi , Sumida Masayuki , Isobe Naoyuki
Published: August 2004

OBJECTIVE AND IMPORTANCE

We report an instructive case of repetitive shunt obstruction caused by mischievous turning of the valve by the patient.

CLINICAL PRESENTATION

A 7-year-old boy underwent shunt replacement for hydrocephalus caused by intraventricular hemorrhage at birth; the shunt had been revised a month earlier. The boy experienced occasional episodes of headache and vomiting after the revision. A shunt survey revealed a twisted tube just proximal to the valve.

INTERVENTION

After the valve was returned to its original position, the symptoms resolved. The patient confessed to a recent habit of turning the valve.

CONCLUSION

Although turning of the valve may be a potential cause of shunt obstruction, the use of craniography and/or a shunt series should be able to reveal these changes.
Pilocytic Astrocytomas in Children: Prognostic Factors—A Retrospective Study of 80 Cases
Authors: Fernandez Carla , Figarella-Branger Dominique , Girard Nadine , Bouvier-Labit Corinne , Gouvernet Joanny , Paredes Armando Paz , Lena Gabriel
Published: August 2004

OBJECTIVE

Pilocytic astrocytomas (PA) are Grade I brain tumors characterized by an excellent prognosis. In some cases, however, the patient has a bad outcome. The aim of our study was to search for the clinicopathological factors underlying the prognosis for patients with this disease.

METHODS

We reviewed the clinical, neuroradiological, and histopathological features of 80 PAs (33 cerebellar, 18 optochiasmatic, 16 brainstem, 7 spinal cord, 3 thalamic, 2 optic nerve, and 1 hemispheric) in pediatric patients.

RESULTS

Pathological examination revealed 58 classic PAs and 20 pilomyxoid astrocytomas, which are a histological variant of PAs. Two cases remained unclassified. The mean overall follow-up period was 58 months, the 5-year progression-free survival rate was 75%, and the 5-year survival rates were 100 and 92% after total and partial removal. Univariate statistical analysis revealed that partial resection, optochiasmatic PA localization, and pilomyxoid variant were associated with a worse prognosis, but the latter two parameters were too closely related to the extent of resection to be independent prognostic factors in multivariate analysis. Among the patients who underwent partial surgical removal, only invasion of the surrounding structures was related to prognosis.

CONCLUSION

PAs are benign tumors, but some clinicopathological factors, such as partial resection, optochiasmatic location, invasion of surrounding structures, and the pilomyxoid variant, have a worse prognosis.
Proton Beam Radiosurgery for Vestibular Schwannoma: Tumor Control and Cranial Nerve Toxicity
Authors: Weber Damien C. , Chan Annie W. , Bussiere Marc R. , Harsh Griffith R. , Ancukiewicz Marek , Barker Fred G. , Thornton Allan T. , Martuza Robert L. , Nadol Joseph B. , Chapman Paul H. , Loeffler Jay S.
Published: August 2004

OBJECTIVE

We sought to determine the tumor control rate and cranial nerve function outcomes in patients with vestibular schwannomas who were treated with proton beam stereotactic radiosurgery.

METHODS

Between November 1992 and August 2000, 88 patients with vestibular schwannomas were treated at the Harvard Cyclotron Laboratory with proton beam stereotactic radiosurgery in which two to four convergent fixed beams of 160-MeV protons were applied. The median transverse diameter was 16 mm (range, 2.5–35 mm), and the median tumor volume was 1.4 cm3 (range, 0.1–15.9 cm3). Surgical resection had been performed previously in 15 patients (17%). Facial nerve function (House-Brackmann Grade 1) and trigeminal nerve function were normal in 79 patients (89.8%). Eight patients (9%) had good or excellent hearing (Gardner-Robertson [GR] Grade 1), and 13 patients (15%) had serviceable hearing (GR Grade 2). A median dose of 12 cobalt Gray equivalents (range, 10–18 cobalt Gray equivalents) was prescribed to the 70 to 108% isodose lines (median, 70%). The median follow-up period was 38.7 months (range, 12–102.6 mo).

RESULTS

The actuarial 2- and 5-year tumor control rates were 95.3% (95% confidence interval [CI], 90.9–99.9%) and 93.6% (95% CI, 88.3–99.3%). Salvage radiosurgery was performed in one patient 32.5 months after treatment, and a craniotomy was required 19.1 months after treatment in another patient with hemorrhage in the vicinity of a stable tumor. Three patients (3.4%) underwent shunting for hydrocephalus, and a subsequent partial resection was performed in one of these patients. The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2–98.3%). Of the 21 patients (24%) with functional hearing (GR Grade 1 or 2), 7 (33.3%) retained serviceable hearing ability (GR Grade 2). Actuarial 5-year normal facial and trigeminal nerve function preservation rates were 91.1% (95% CI, 85–97.6%) and 89.4% (95% CI, 82–96.7%). Univariate analysis revealed that prescribed dose (P = 0.005), maximum dose (P = 0.006), and the inhomogeneity coefficient (P = 0.03) were associated with a significant risk of long-term facial neuropathy. No other cranial nerve deficits or cancer relapses were observed.

CONCLUSION

Proton beam stereotactic radiosurgery has been shown to be an effective means of tumor control. A high radiological response rate was observed. Excellent facial and trigeminal nerve function preservation rates were achieved. A reduced prescribed dose is associated with a significant decrease in facial neuropathy.
Brachial Plexus Variations in Human Fetuses
Authors: Uysal İsmihan İlknur , Şeker Muzaffer , Karabulut Ahmet Kağan , Büyükmumcu Mustafa , Ziylan Taner
Published: August 2004

OBJECTIVE

We examined the anatomic variations of the brachial plexus (BP) in human fetuses.

METHODS

This study was performed with 200 BPs from spontaneously aborted fetuses without detectable malformations. The plexuses were dissected, and the normal position and/or morphological variations of the BP were determined and photographed.

RESULTS

There were no variations in 93 plexuses, and 107 plexuses were observed to have different variations. Morphological variations were observed more frequently among female fetuses and right sides. The BPs were composed mostly of the C5, C6, C7, and C8 nerves and the T1 nerve (71.5%). A prefixed plexus was observed in 25.5% of cases, and a postfixed plexus was observed in 2.5% of cases. In one case (0.5%), the C4 and T2 nerves joined the formation. The inferior trunk was not formed in 9% of cases. The superior trunk was not formed in 1% of cases. In one plexus, the superior trunk was formed by the ventral rami of the C4 and C5 nerves. In one case, the inferior trunk was formed by the ventral rami of the T1 and T2 nerves. Division variations were observed most frequently. There were also variations in the terminal branches, such as the roots of the median nerve joining in the distal part of the arm (8.5%), the axillary nerve being separate from the posterior division of the superior trunk (2.5%), and a connection existing between the median and musculocutaneous nerves (1%).

CONCLUSION

Knowledge of BP variations is important for surgeons who perform surgical procedures in the cervical and axillary regions.
A Reappraisal of Angioplasty and Stenting for the Treatment of Vertebral Origin Stenosis
Authors: Albuquerque Felipe C. , Fiorella David , Han Patrick , Spetzler Robert F. , McDougall Cameron G.
Published: August 2004

OBJECTIVE

To assess the rate of restenosis after vertebral origin angioplasty and stenting (VOAS).

METHODS

We reviewed the records of 33 patients (24 men, 9 women; age range, 49–81 yr; mean, 64.5 yr) who underwent VOAS during a period of 5 years and followed each for the development of adverse sequelae through a prospectively maintained database. A neuroradiologist not involved in the stenting procedures assessed original and follow-up angiograms for evidence of restenosis. Restenosis was quantified as insignificant (0–24%), mild (25–49%), moderate (50–74%), or severe (75–100%).

RESULTS

Of the 33 patients, 30 presented with transient ischemic attacks or stroke. Most (31 of 33 patients) manifested other brachiocephalic stenoses, including 27 patients with occlusion, hypoplasia, or stenosis of the contralateral vertebral artery. Angiographic follow-up (mean, 16.2 mo) was obtained in 30 patients (2 patients died before follow-up, and 1 refused). Restenosis was mild in seven patients, moderate in eight, and severe in five. The combined rate of moderate-to-severe restenosis was 43.3%. No complications resulted in permanent morbidity. One patient died as a result of a stroke in a different vascular distribution 4 months after VOAS. Another patient died as a result of basilar thrombosis in which emergent stenting had been undertaken in an effort to perform thrombolysis.

CONCLUSION

Despite a technical success rate of 97% and a low incidence of complications, VOAS is associated with a high rate of moderate-to-severe restenosis.
Results of Endovascular Treatment of Internal Carotid Artery Stenoses with a Newly Developed Balloon Protection Catheter
Authors: Terada Tomoaki , Tsuura Mitsuharu , Matsumoto Hiroyuki , Masuo Osamu , Yamaga Hiroo , Tsumoto Tomoyuki , Itakura Toru
Published: August 2004

OBJECTIVE

A new balloon protection catheter to prevent distal emboli during internal carotid artery percutaneous transluminal angioplasty and stenting was developed, and its efficacy was evaluated in both an experimental model and clinical cases.

METHODS

The balloon protection catheter was navigated over a steerable 0.014-inch guidewire to negotiate tight stenoses and sharp bends, which would cause difficulties for the passage of a flow-directed balloon catheter. Percutaneous transluminal angioplasty and stenting were performed for 85 consecutive patients with 87 stenotic lesions of the cervical internal carotid artery, with two different methods using this protection system. Distal protection was provided only after dilation for the initial 38 lesions (Group I), but the latter 49 lesions were treated in both the pre- and postdilation periods (Group II). The effects of using the balloon protection catheter with the embolic debris clearance technique were evaluated with pre- and postoperative magnetic resonance imaging for each group.

RESULTS

The balloon protection catheter was introduced beyond the stenosis in all cases. In Group I, one symptomatic embolic stroke was caused by distal embolization resulting from atheromatous plaque, and high-intensity areas appeared on diffusion-weighted magnetic resonance imaging scans in 47% of cases. In contrast, in Group II, there were no strokes related to the procedure, although one patient with multiple risk factors died suddenly on the second day after stenting. Diffusion-weighted imaging scans demonstrated small, high-intensity areas in 19% of cases in Group II. The overall morbidity/mortality rate in our series was 2.3%.

CONCLUSION

Our new balloon protection catheter was reliably navigated across internal carotid artery stenoses and reduced distal embolism in clinical cases.
Meningiomas Involving the Optic Nerve: Technical Aspects and Outcomes for a Series of 50 Patients
Authors: Margalit Nevo S. , Lesser Jonathan B. , Moche Jason , Sen Chandranath
Published: August 2004

OBJECTIVE

Surgical strategies and results for 50 patients with meningiomas involving the optic nerves are discussed and evaluated. Factors affecting the degree of resection and patient outcomes are presented. We emphasize our surgical techniques for resection of these tumors and we discuss the advantages of different approaches, depending on the relationship of the tumor to the optic nerves.

METHODS

Data for 50 patients with meningiomas involving the optic nerves who were surgically treated between 1991 and 2002 were reviewed, by using patient files, operative notes, and pre- and postoperative imaging and ophthalmological examination findings.

RESULTS

Thirty-one female patients and 19 male patients, with a mean age of 53 years, were treated. Thirty-one patients (62%) underwent complete tumor removal (Simpson Grade 1 or 2), and 19 patients underwent subtotal removal (Grade 4). Factors affecting the grade of resection were tumor size (P = 0.01), location (P = 0.007), and internal carotid artery encasement (P = 0.019). Patients who underwent Grade 1 or 2 resection exhibited a mean tumor size of 3.0 cm, and patients who underwent Grade 4 resection exhibited a mean tumor size of 4.1 cm. Only three patients had residual tumor on the optic nerve; all others had tumor in the cavernous sinus or at the orbital apex or exhibited vascular involvement. Visual outcomes were influenced predominantly by tumor size, preoperative visual function, and optic nerve encasement.

CONCLUSION

Meningiomas that involve the optic nerves require special considerations and surgical techniques. Early decompression of the optic nerve within the bony canal allows identification and separation of the tumor from the nerve, permitting removal of the tumor from this area with minimal manipulation of the optic nerve.
Spontaneous Resolution of Syringomyelia: Report of Two Cases and Review of the Literature
Authors: Kyoshima Kazuhiko , Bogdanov Enver I.
Published: August 2004

OBJECTIVE AND IMPORTANCE

The natural history of syringomyelia is highly unpredictable, and some patients experience improvement or stabilization without surgery. However, the mechanisms of the formation and spontaneous resolution of syringomyelia remain controversial. This report concerns two patients with syringomyelia who demonstrated spontaneous reductions in syrinx size, accompanied by symptomatic improvement.

CLINICAL PRESENTATION

One patient was a 10-year-old girl with syringomyelia associated with a tight cisterna magna and basilar impression, who demonstrated a spontaneous decrease in syrinx size, accompanied by symptomatic improvement, in 22 months. The other patient was a 39-year-old man with syringomyelia associated with a Chiari I malformation, who demonstrated a spontaneous reduction in syrinx size and neurological improvement, accompanied by elevation of the cerebellar tonsils, 6 months after diagnosis.

INTERVENTION

The patients were monitored.

CONCLUSION

The mechanisms of spontaneous resolution of syringomyelia, as well as the factors leading to the cerebrospinal fluid flow disturbances that cause syringomyelia, may vary. Resolution of foramen magnum lesion-related syringomyelia may be the result of spontaneous correction of the abnormal cerebrospinal fluid flow, as observed in our cases, or of cavity fluid drainage into the spinal arachnoid space because of spinal cord fissuring.
What Is the Best Method for Reporting Tumor Diameter in Vestibular Schwannoma?
Authors: Tanaka Yuichiro , Hongo Kazuhiro , Tada Tsuyoshi , Kobayashi Shigeaki
Published: August 2004

OBJECTIVE

Various methods have been used to report the tumor diameter of vestibular schwannomas. To clarify the most appropriate method to represent the tumor volume, tumor diameters according to various measuring methods were statistically compared with the actual tumor volume.

METHODS

Tumor volume was measured by three-dimensional constructive interference in steady state images in 52 unselected vestibular schwannomas. Pearson's correlation coefficient was obtained between the tumor volume and various tumor diameters, such as diameter parallel to the petrous edge (a); a pons-to-petrous diameter (b); √ab, a maximum diameter of the portion in the cerebellopontine angle cistern (max CPA); a maximum diameter of the whole tumor (Max); and a diameter through an axis of the internal auditory canal (Axis). The tumors were divided into three groups on the basis of tumor volume, as follows: Group I (small, &3x003C;0.5 cm3), Group II (medium, 0.5–2 cm3), and Group III (large, >2 cm3).

RESULTS

Max and Axis correlated best with the tumor volume in Group I and correlated least with the tumor volume in Group II. Any of these measurements was acceptable in Group III tumors. The max CPA consistently revealed good correlation with the tumor volume in all three tumor groups.

CONCLUSION

The max CPA measurement is the simplest and most appropriate way to represent the tumor volume in unselected tumors. Max or Axis is better only when small tumors (<0.5 cm3 in volume) are being assessed—that is, those with a max CPA of less than 1 cm.
Seeding of a Cavernous Angioma with Mycoplasma hominis: Case Report
Authors: House Paul , Dunn James , Carroll Karen , MacDonald Joel
Published: August 2004

OBJECTIVE AND IMPORTANCE

To describe a unique case of hematogenous seeding of a cavernous angioma with the commensal organism Mycoplasma hominis.

CLINICAL PRESENTATION

A 40-year-old female patient presented with a severe headache and acute left facial nerve palsy. Imaging studies revealed a right frontal mass lesion with characteristics of a cavernous angioma.

INTERVENTION

The patient underwent a craniotomy for cavernous angioma resection. Purulent material was noted at the time of resection, and no hemorrhage was observed. Despite antibiotic therapy, the patient required repeat craniotomies for subsequent abscess treatment. M. hominis was identified as the pathogen.

CONCLUSION

M. hominis is a rare cause of brain abscesses and can be difficult to eradicate. Cavernous angiomas can be seeded hematogenously.
Comparison of the Far Lateral and Extreme Lateral Variants of the Atlanto-occipital Transarticular Approach to Anterior Extradural Lesions of the Craniovertebral Junction
Authors: Kawashima Masatou , Tanriover Necmettin , Rhoton Albert L. , Ulm Arthur J. , Matsushima Toshio
Published: August 2004

OBJECTIVE

Managing lesions situated in the anterior aspect of the craniovertebral junction (CVJ) remains a challenging neurosurgical problem. The purposes of this study were to examine the microsurgical anatomy of the anterior extradural aspect of the CVJ and the differences in the exposure obtained by the far lateral and extreme lateral atlanto-occipital transarticular approaches. The far lateral approach, as originally described, is a lateral suboccipital approach directed behind the sternocleidomastoid muscle and the vertebral artery and just medial to the occipital and atlantal condyles and the atlanto-occipital joint. The extreme lateral approach, as originally described, is a direct lateral approach deep to the anterior part of the sternocleidomastoid muscle and behind the internal jugular vein along the front of the vertebral artery. Both approaches permit drilling of the condyles at the atlanto-occipital joint but provide a different exposure because of the differences in the direction of the approach.

METHODS

Fifteen adult cadaveric specimens were studied using a magnification of ×3 to ×40 after perfusion of the arteries and veins with colored silicone. The microsurgical anatomy of the extradural aspects of the CVJ and the two atlanto-occipital transarticular approaches were examined in stepwise dissections.

RESULTS

The far lateral atlanto-occipital transarticular approach provides excellent exposure of the extradural lesions located in the ipsilateral anterior and anterolateral aspects of the extradural region of the CVJ. The extreme lateral atlanto-occipital transarticular approach provides excellent exposure, not only on the side of the exposure, but also extending across the midline to the medial aspect of the contralateral atlanto-occipital joint and the lower clivus.

CONCLUSION

The far lateral and extreme lateral variants of the atlanto-occipital transarticular approach provide an alternative to the transoral approach to the anterior extradural structures at the CVJ. Compared with the transoral approach, both approaches provide a shorter operative route, avoid the contaminated nasopharynx, reduce the incidence of cerebrospinal fluid leak, and are not limited laterally by the atlanto-occipital joint.
Ventriculosagittal Sinus Shunt Placement: Technical Case Report
Authors: Samadani Uzma , Mattielo Julian A. , Sutton Leslie N.
Published: August 2004

OBJECTIVE AND IMPORTANCE

Determining an appropriate site for distal catheter placement for ventricular shunting for some hydrocephalic patients can be difficult. We describe a simplification of the technique for sagittal sinus shunt placement using a guidewire.

CLINICAL PRESENTATION

A 20-month-old infant with hydrocephalus secondary to Alexander's disease developed erosion of her parieto-occipital ventriculoperitoneal shunt reservoir through an occipital decubitus scalp ulceration. Her hydrocephalus was temporarily treated with a ventriculostomy; however, she developed pneumatosis intestinalis while in the hospital.

TECHNIQUE

The patient underwent placement of a ventriculosagittal sinus shunt. The ventricular catheter and shunt valve were placed through a burr hole at Kocher's point, and the distal end of the catheter was placed in the superior sagittal sinus by using the Seldinger technique.

CONCLUSION

Ventriculosagittal sinus shunting may be used as an alternative to traditional methods for patients for whom distal shunt placement is problematic. Our technique has the theoretical advantage of reducing the risks of blood loss or air embolism by not requiring a scalpel incision into the sinus.
Adjacent Segment Disease: An Uncommon Complication after Cervical Expansile Laminoplasty: Case Report
Authors: Wang Michael Y. , Green Barth A. , Vitarbo Elizabeth , Levi Allan D.O.
Published: August 2004

OBJECTIVE AND IMPORTANCE

Adjacent segment disc disease is a well-described phenomenon that occurs after anterior cervical spinal fusion. One of the advantages of cervical laminoplasty over anterior approaches is that although the treated segments are stiffened, no formal fusion is performed. This is thought to reduce the biomechanical stresses placed on adjacent levels and thus decrease the likelihood of adjacent level degeneration.

CLINICAL PRESENTATION

A 62-year-old man presented with myelopathy attributable to cervical spondylosis and underwent a C3–C7 laminoplasty. Improvements in gait were followed 2 years later by symptomatic disc degeneration and spinal cord compression at T1–T2, which rendered him wheelchair bound.

INTERVENTION

The patient was treated with a laminectomy at the level of stenosis accompanied by posterior instrumentation and fusion from C5 to T3. This resulted in clinical improvement, and the patient was returned to his baseline ambulatory status.

CONCLUSION

Adjacent segment disease is an uncommon complication that occurs after laminoplasty. Careful attention to preserving facet joint motion in the cervical spine may minimize the stresses placed on adjacent motion segments.
Risk of Postoperative Hemorrhage after Intracranial Surgery after Early Nadroparin Administration: Results of a Prospective Study
Authors: Gerlach Rüdiger , Scheuer Timm , Beck Jürgen , Woszczyk Alina , Böhm Martina , Seifert Volker , Raabe Andreas
Published: August 2004

OBJECTIVE

Early postoperative pharmacological prophylaxis of deep vein thrombosis after intracranial surgery is still a matter of debate because of concerns regarding the formation of postoperative hematoma. The objective of this study was to prospectively analyze the rate of postoperative hemorrhage during a 3-year period of early postoperative administration of the low molecular weight heparin nadroparin (Fraxiparin) plus compression stockings in a large cohort of patients undergoing intracranial surgery.

METHODS

A total of 2823 intracranial neurosurgical procedures, performed between June 1999 and 2002, were studied. Of these operations, 1319 (46.7%) were major intracranial surgical procedures (Group 1). Group 2 comprised 1504 operations (53.3%) considered to be minor surgical procedures (e.g., shunt procedures, biopsies). All patients except those with transnasal transsphenoidal removal of pituitary tumors underwent early postoperative imaging (computed tomography or magnetic resonance imaging) to determine postoperative hemorrhage. All significant postoperative hematomas (defined as those requiring surgical evacuation because of relevant space occupation and/or neurological deterioration) were treated surgically. Prophylaxis of venous thromboembolic events included early (<24 h) postoperative administration of 0.3 ml nadroparin subcutaneously plus intra- and postoperative compression stockings until discharge.

RESULTS

Forty-three major postoperative hemorrhages (1.5%) were observed after 2823 intracranial procedures (95% confidence interval, 1.1–2.05). Forty-two (3.2%) of 1319 postoperative hematomas occurred in patients undergoing major intracranial procedures (Group 1). There was only 1 (0.07%) significant hemorrhage after 1504 minor intracranial procedures (Group 2). A subgroup analysis of patients who needed preoperative anticoagulation because of medical comorbidity did not reveal an increased frequency of postoperative hematoma when anticoagulation was stopped 24 hours before surgery P = 0.1, χ2 test; 95% confidence interval, 0.89–3.0).

CONCLUSION

This report describes the largest prospective study conducted to date to determine the hemorrhage rate after early postoperative anticoagulation. The results support the concept of postoperative pharmacological thromboembolic prophylaxis in patients undergoing intracranial surgery.
Hypofractionated Conformal Stereotactic Radiotherapy for Arteriovenous Malformations
Authors: Lindvall Peter , Bergström Per , Löfroth Per-Olov , Hariz Marwan I. , Henriksson Roger , Jonasson Per , Bergenheim A. Tommy
Published: August 2004

OBJECTIVE

Arteriovenous malformations (AVMs) are congenital vascular lesions that are associated with high morbidity and mortality if left untreated. There are several options for treatment, including radiotherapy. Safe and effective single-fraction radiotherapy for patients with large AVMs has been considered difficult.

METHODS

Between December 1986 and June 2001, 36 patients with cerebral AVMs were treated with hypofractionated conformal stereotactic radiotherapy at Umeå University Hospital. Twenty-nine patients have been followed angiographically to date and are reported in this study.

RESULTS

Twenty-four (83%) of 29 patients (mean AVM volume, 11.5 cm3) underwent complete obliteration of their AVMs. The rates of angiographically verified total obliteration at 2 years after treatment were 56% for AVMs 4 to 10 cm3 and 50% for AVMs larger than 10 cm3. The obliteration rate increased considerably with extended follow-up. Five years after treatment, the obliteration rates were 81% for AVMs 4 to 10 cm3 and 70% for AVMs larger than 10 cm3.

CONCLUSION

Hypofractionated conformal stereotactic radiotherapy may be an important alternative to single-fraction radiotherapy in patients with large AVMs or AVMs located in eloquent areas, because it allows the administration of a higher radiation dose than is possible to deliver in single-fraction radiosurgery. With our technique of hypofractionated conformal stereotactic radiotherapy, the rate of obliterating AVMs was comparable to that of single-dose radiosurgery, although the volumes of the irradiated AVMs in our study were larger than those reported previously.
Increases in Cardiac Output Can Reverse Flow Deficits from Vasospasm Independent of Blood Pressure: A Study Using Xenon Computed Tomographic Measurement of Cerebral Blood Flow
Authors: Kim Dong H. , Joseph Mathew , Ziadi Saleem , Nates Joseph , Dannenbaum Mark , Malkoff Marc
Published: August 2004

INTRODUCTION

Vasospasm after subarachnoid hemorrhage remains a management challenge. The accepted treatment involves hypertensive, hypervolemic, hemodilution therapy. However, there is variation in the application of this treatment. Most authors increase mean arterial pressure (MAP), which can be associated with significant morbidity. Others increase cardiac output (CO). In this study, we examined the relationship between volume status, CO, and MAP and cerebral blood flow (CBF) in the setting of vasospasm.

METHODS

A xenon blood flow tomography-based system was used to quantitate CBF. Sixteen patients with vasospasm after subarachnoid hemorrhage were treated with hypervolemia, phenylephrine to increase MAP, or dobutamine to increase CO. Direct CBF measurements were obtained before and after treatment. A strength of this study is that only one variable (central venous pressure, MAP, or CO) was manipulated in each patient, and the effect of this change was measured immediately.

RESULTS

With phenylephrine, mean MAP increased from 102.4 to 132.1 mm Hg. In regions of diminished CBF due to vasospasm, mean CBF increased from 19.2 to 33.7 ml/100 g/min. Similarly, dobutamine increased the cardiac index from a mean of 4.1 to 6.0 L/min/m2 and slightly decreased MAP. CBF increased from a mean of 24.8 to 35.4 ml/100 g/min. Both were statistically significant changes. With hypervolemia, the average central venous pressure increased from a mean of 5.4 to 7.3 cm H2O; no changes in mean CBF were noted.

CONCLUSION

This article reports the first human study that shows with direct measurements the independent influence of CO in the setting of vasospasm. Increases in CO without changes in MAP can elevate CBF. This finding has immediate clinical application because CO manipulation is much safer than increasing MAP. Because both interventions were equally efficacious, our protocol has been changed to augment CO as a first measure. Induced hypertension is reserved for patients in whom this initial treatment fails.
Clinical Characteristics of Silent Corticotrophic Adenomas and Creation of an Internet-accessible Database to Facilitate Their Multi-institutional Study
Authors: Webb K. Michael , Laurent Jeffrey J. , Okonkwo David O. , Lopes M. Beatriz , Vance Mary Lee , Laws Edward R.
Published: August 2004

OBJECTIVE

Silent corticotrophic adenomas (SCAs) of the pituitary gland present as clinically nonfunctioning sellar lesions, with normal serum and urine hormone testing results, but stain positively for adrenocorticotropic hormone in immunohistochemical analyses. These tumors are now more readily recognized, but determination of their natural history and responses to treatment is difficult because of their rarity. We report the diagnoses and outcomes for a series of patients with SCAs, and we describe the creation of an Internet-accessible database (www.hsc.virginia.edu/neuro/neurosurgery/pituitary.html) for collection of multi-institutional data on these lesions.

METHODS

The medical records of patients with documented SCAs who were treated at the University of Virginia between 1991 and 2002 were reviewed. A comprehensive data collection form was then created and posted online.

RESULTS

Twenty-seven patients with SCAs were identified, with a female predominance (70%, P = 0.04). Headache was the most common presenting symptom (70%), followed by visual field deficits (52%), acute or subacute pituitary apoplexy (33%), cavernous sinus syndrome (18.5%), and hypopituitarism (11.1%). Extrasellar extension was noted for 92.6% of patients on preoperative magnetic resonance imaging scans. Transsphenoidal surgery was performed for all patients. Follow-up information was available for all patients (median, 60 mo; range, 3–254 mo). Postoperatively, 33% of patients received radiotherapy. Recurrence was noted for 37% of all patients and 41.7% of patients who did not receive postoperative radiotherapy.

CONCLUSION

SCAs, although clinically nonfunctioning, may behave like aggressive adrenocorticotropic hormone-secreting adenomas and therefore should receive vigorous follow-up monitoring, with consideration being given to the recommendation of radiotherapy in cases with residual tumor.
Stimulation of the Subthalamic Nucleus in Parkinson's Disease Does Not Produce Striatal Dopamine Release
Authors: Abosch Aviva , Kapur Shitij , Lang Anthony E. , Hussey Doug , Sime Elspeth , Miyasaki Janis , Houle Sylvain , Lozano Andres M.
Published: August 2004

OBJECTIVE

The subthalamic nucleus (STN) is a target in the surgical treatment of Parkinson's disease (PD). The mechanism by which electrical stimulation of the STN ameliorates symptoms of PD remains unknown. One consistent aspect of STN stimulation is the ability to reduce the dosage of dopaminergic medications; sometimes they can be eliminated altogether. Furthermore, nigrostriatal projection axons are apposed to the dorsal surface of the STN and are likely affected by the application of current in this region. We sought to determine whether STN stimulation could release endogenous striatal dopamine.

METHODS

Five patients with PD, who had previously undergone surgical implantation of bilateral STN stimulators, underwent [11C]raclopride positron emission tomographic scanning. l-dopa was withheld for 12 hours, and both stimulators were turned off 9 hours before scanning. We assayed for striatal dopamine release by measuring radioligand displacement as a consequence of turning on the right STN stimulator after 45 minutes of a 90-minute [11C]raclopride infusion. Patients were evaluated with the motor section of the Unified Parkinson's Disease Rating Scale before and after the studies.

RESULTS

Comparisons between the right and left striata, before and after right STN stimulation, demonstrated no significant differences in [11C]raclopride binding, despite significant improvements in Unified Parkinson's Disease Rating Scale motor scores with unilateral stimulation (mean improvement, 26.0 ± 16.4%; P < 0.05). This finding was also noted when the striatum was partitioned into dorsal and ventral caudate and putamen and the four regions were analyzed separately.

CONCLUSION

Our results suggest that STN stimulation does not mediate its anti-PD effects via the release of dopamine, as assessed with [11C]raclopride displacement.
Zones of Approach for Craniofacial Resection: Minimizing Facial Incisions for Resection of Anterior Cranial Base and Paranasal Sinus Tumors
Authors: Liu James K. , Decker David , Schaefer Steven D. , Moscatello Augustine L. , Orlandi Richard R. , Weiss Martin H. , Couldwell William T.
Published: August 2004

OBJECTIVE

Anterior cranial base tumors are surgically resected with combined craniofacial approaches that frequently involve disfiguring facial incisions and facial osteotomies. The authors outline three operative zones of the anterior cranial base and paranasal sinuses in which tumors can be resected with three standard surgical approaches that minimize transfacial incisions and extensive facial osteotomies.

METHODS

The zones were defined by performing dissections on 10 cadaveric heads and by evaluating radiographic images of patients with anterior cranial base tumors. The three approaches performed on each cadaver were transbasal, transmaxillary, and extended transsphenoidal.

RESULTS

Three zones of approach were defined for accessing tumors of the anterior cranial base, nasal cavity, and paranasal sinuses. Zone 1 is exposed by the transbasal approach, which is limited anteriorly by the supraorbital rim, posteriorly by the optic chiasm and clivus, inferiorly by the palate, and laterally by the medial orbital walls. This approach allows access to the entire anterior cranial base, nasal cavity, and the majority of maxillary sinuses. The limitation imposed by the orbits results in a blind spot in the superolateral extent of the maxillary sinus. Zone 2 is exposed by a sublabial maxillotomy approach and accesses the entire maxillary sinus, including the superolateral blind spot and the ipsilateral anterior cavernous sinus. However, access to the anterior cranial base is limited. Zone 3 is exposed by the transsphenoidal approach. This approach accesses the midline structures but is limited by the lateral nasal walls and intracavernous carotid arteries. An extended transsphenoidal approach allows further exposure to the anterior cranial base, clivus, or cavernous sinuses. The use of the endoscope facilitates tumor resection in the nasal cavity and paranasal sinuses.

CONCLUSION

The operative zones outlined offer minimally invasive craniofacial approaches to accessing lesions of the anterior cranial base and paranasal sinuses, obviating facial incisions and facial osteotomies. Case illustrations demonstrating the approach selection paradigm are presented.