bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of Distal Posteroinferior Cerebellar Artery Aneurysms
Authors: Horiuchi Tetsuyoshi , Tanaka Yuichiro , Hongo Kazuhiro , Nitta Junpei , Kusano Yoshikazu , Kobayashi Shigeaki 
Published: August 2004

Abstract

OBJECTIVE
Distal posteroinferior cerebellar artery (PICA) aneurysms are rare and have not been well investigated previously. We report our series of 24 patients with 27 distal PICA aneurysms.

METHODS
All patients with distal PICA aneurysms that were surgically treated at Shinshu University Hospital and its affiliated hospitals between 1983 and 2001 were reviewed retrospectively. Data relating to clinical, radiological, and intraoperative findings were analyzed.

RESULTS
In our series, distal PICA aneurysms reached an incidence of 0.28 and 0.38% of all intracranial aneurysms and ruptured aneurysms, respectively. There were 23 ruptured and 4 unruptured distal PICA aneurysms. Of these, 74.1% were saccular, 7.4% fusiform, and 18.5% dissecting aneurysms. Primarily the telovelotonsillar segment of the PICA was affected. Usually, the surgical outcome was favorable and was influenced by the obstructive hydrocephalus and the preoperative grade. It was sometimes difficult to detect the ruptured distal PICA aneurysm on the initial angiogram, and an extracranial origin of the PICA was sometimes observed.

CONCLUSION
This review summarizes the presentation and outcome of a large series of 24 patients with 27 distal PICA aneurysms, and we conclude that distal PICA aneurysms are benign entities compared with vertebral artery-PICA aneurysms. Characteristics that should be considered in the treatment of distal PICA aneurysms are discussed.
Epithelioid Ependymoma: A New Variant of Ependymoma: Report of Three Cases
Authors: Kleinman George M. , Zagzag David , Miller Douglas C. 
Published: August 2004

Abstract

OBJECTIVE
To describe the pathological features of three very similar and unusual primary central nervous system tumors that are not readily recognized as conventional ependymomas but which, by ultrastructural examination, have an ependymomatous character.

METHODS
Three distinctive tumors were found in a review of our files for cases of ependymoma. In each case, hematoxylin and eosin-stained sections were reviewed, and immunostains for epithelial membrane antigen, cytokeratin, vimentin, and glial fibrillary acidic protein were performed on formalin-fixed, paraffin-embedded sections. Electron microscopy was performed in each case.

RESULTS
The tumors had a diffuse myxoid background, often containing tightly clustered cells that mimicked multinucleated giant cells, but lacking perivascular pseudorosettes or central lumen rosettes. Glial fibrillary acidic protein and vimentin immunostains did not reveal perivascular processes. Epithelial membrane antigen immunostains showed a dot-like cytoplasmic immunoreactivity in some cell clusters in two of the three cases. Cytokeratin was negative in all three cases. However, ultrastructurally, the cells of each tumor had extensive surface microvilli; the giant cell-like clusters had cells with extensive close appositions, some junctions, and, in two cases, lumina with microvilli. Two of the patients were adults (both with temporal lobe tumors), and one patient was 13 years old and had a cervical spinal cord intramedullary tumor. Each tumor was sharply circumscribed from adjacent central nervous system tissue but was not encapsulated. One of the cases in an adult was mitotically highly active; this tumor recurred locally 4 years after initial gross total excision.

CONCLUSION
These tumors are unusual variants of ependymoma. This pattern of ependymoma is sufficiently distinctive to be recognized in hematoxylin and eosin stains once the architecture of the epithelioid clusters is appreciated.
The Predictive Value of Sympathetic Block for the Success of Spinal Cord Stimulation
Authors: Hord E. Daniela , Cohen Steven P. , Cosgrove G. Rees , Ahmed Shihab U. , Vallejo Ricardo , Chang Yuchiao , Stojanovic Milan P. 
Published: August 2004

Abstract

OBJECTIVE
The purpose of this study was to assess the predictive value of response to sympathetic blockade (SB) on the success rate of spinal cord stimulation (SCS) in patients with complex regional pain syndrome.

METHODS
We performed a retrospective study on 23 patients with complex regional pain syndrome who underwent both SB and subsequent SCS trials in the past 3 years at the Massachusetts General Hospital Pain Center, Boston, MA, and Walter Reed Army Medical Center, Washington, DC. Fifteen of these patients underwent permanent placement of an SCS device, and pain relief at 1- and 9-month follow-up was recorded.

RESULTS
Among the 23 patients included in the study, those having transient pain relief with SB were more likely to have a positive SCS trial: all 13 with positive SB had good pain relief during the trial, compared with only 3 of the 10 with negative SB (100% versus 30%, P &lt; 0.001). Among the 10 patients with negative SB, 7 noted poor pain relief during the trial despite adequate coverage, and they did not undergo placement of a permanent device. Among the patients who underwent permanent placement of an SCS device, those who received good pain relief with SB were more likely to have greater than 50% pain relief at 1-month follow-up (100% versus 33%, P = 0.029) and 9-month follow-up (87.5% versus 33.3%, P = 0.15).

CONCLUSION
We conclude that patients with good response to SB before SCS are more likely to have a positive response during their SCS trial and long-term pain relief after placement of permanent SCS device.
Recurrence of a Vertebral Artery Dissecting Pseudoaneurysm after Successful Stent-supported Coil Embolization: Case Report
Authors: MacKay Christopher I. , Han Patrick P. , Albuquerque Felipe C. , McDougall Cameron G. 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Dissecting aneurysms of the intracranial vertebral artery are increasingly recognized as a cause of subarachnoid hemorrhage. We present a case involving technical success of the stent-supported coil embolization but with recurrence of the dissecting pseudoaneurysm of the intracranial vertebral artery. The implications for the endovascular management of ruptured dissecting pseudoaneurysms of the intracranial vertebral artery are discussed.

CLINICAL PRESENTATION
A 36-year-old man with a remote history of head injury had recovered functionally to the point of independent living. He experienced the spontaneous onset of severe head and neck pain, which progressed rapidly to obtundation. A computed tomographic scan of the head revealed subarachnoid hemorrhage centered in the posterior fossa. The patient underwent cerebral angiography, which revealed dilation of the distal left vertebral artery consistent with a dissecting pseudoaneurysm.

INTERVENTION
Transfemoral access was achieved under general anesthesia, and two overlapping stents (3 mm in diameter and 14 mm long) were placed to cover the entire dissected segment. Follow-up angiography of the left vertebral artery showed the placement of the stents across the neck of the aneurysm; coil placement was satisfactory, with no residual aneurysm filling. Approximately 6 weeks after the patient's initial presentation, he developed the sudden onset of severe neck pain. A computed tomographic scan showed no subarachnoid hemorrhage, but computed tomographic angiography revealed that the previously treated left vertebral artery aneurysm had recurred. Angiography confirmed a recurrent pseudoaneurysm around the previously placed Guglielmi detachable coils. A test balloon occlusion was performed for 30 minutes. The patient's neurological examination was stable throughout the test occlusion period. Guglielmi detachable coil embolization of the left vertebral artery was then performed, sacrificing the artery at the level of the dissection. After the procedure was completed, no new neurological deficits occurred. On the second day after the procedure, the patient was discharged from the hospital. He was alert, oriented, and able to walk.

CONCLUSION
We appreciate the value of preserving a parent vessel when a dissecting pseudoaneurysm of the intracranial vertebral artery ruptures in patients with inadequate collateral blood flow, in patients with disease involving the contralateral vertebral artery, or in patients with both. However, our case represents a cautionary note that patients treated in this fashion require close clinical follow-up. We suggest that parent vessel occlusion be considered the first option for treatment in patients who will tolerate sacrifice of the parent vessel along its diseased segment. In the future, covered stent technology may resolve this dilemma for many of these patients.
Presacral Arteriovenous Fistula: Case Report
Authors: Kähärä Veikko , Lehto Ulla , Sajanti Juha 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
We describe a case of arteriovenous fistula in front of the sacrum. Drainage induced epidural venous dilation in the sacral spinal canal. The fistula was embolized endoarterially with n-butyl-2-cyanoacrylate via its iliac arterial feeders. In follow-up digital subtraction angiography 1 month later, the fistula was found to be totally closed. The patient was followed up clinically for 2.5 years. She has remained symptom-free.

CLINICAL PRESENTATION
A previously healthy 43-year-old woman presented with severe gluteal and perineal pain and a local sensation of hyperesthesia. The primary computed tomographic scan of the lumbosacral spine was normal, and emergency laparoscopy showed no signs of any pathological lesions. Magnetic resonance imaging discovered an unidentified mass in the sacral spinal canal, and the patient was hospitalized for neurosurgery. However, surgery on this mass had to be discontinued because of profuse bleeding, and the patient was referred for angiography.

INTERVENTION
Diagnostic catheter angiography revealed a high-flow arteriovenous fistula anterior to the sacrum, and the mass detected earlier by magnetic resonance imaging seemed to be a dilated epidural vein draining the fistula. The feeders of the fistula originated in both internal iliac arteries, and the fistula was occluded via these arteries in two angiographic sessions.

CONCLUSION
A paraspinal arteriovenous fistula may have venous drainage through the epidural venous plexus, and the ectatic veins may induce radicular symptomology. To the best of our knowledge, a paraspinal fistula at such a presacral location has not been documented previously. An unidentified mass in the sacral spinal canal should be suspected of being a dilated vascular structure. Prompt angiographic examinations with an option for embolization should be performed, and open surgical intervention should be avoided.
Coregistration Accuracy and Detection of Brain Shift Using Intraoperative Sononavigation during Resection of Hemispheric Tumors
Authors: Keles G. Evren , Lamborn Kathleen R. , Berger Mitchel S. 
Published: August 2004

Abstract

OBJECTIVE
Sononavigation, which combines real-time anatomic ultrasound data with neuronavigation techniques, is a potentially valuable adjunct during the surgical excision of brain tumors.

METHODS
In this study, we report our preliminary observations using this technology on 58 adult patients harboring hemispheric tumors. Data regarding coregistration accuracy was collected from various landmarks that typically do not shift as well as from tumor boundaries and the cortical surface. In a subset of patients, we evaluated the extent and direction of postresection brain displacement and its relationship with patient age, tumor histology, tumor volume, and use of mannitol.

RESULTS
For all structures excluding the cortex, average coregistration accuracy measurements between ultrasound and preoperatively acquired magnetic resonance imaging scans were within the range of 2 mm. The most accurate alignments were obtained with the choroid plexus and the falx, and the least reliable structure in terms of coregistration accuracy was the cortical surface.

CONCLUSION
Sononavigation provides real-time information during tumor removal in alignment with the preoperative magnetic resonance imaging scans, thus enabling the surgeon to detect intraoperative hemorrhage, cyst drainage, and tumor resection, and it allows for calculation of brain shift during the use of standard navigation techniques.
Stereotactic Radiosurgery as an Alternative to Fractionated Radiotherapy for Patients with Recurrent or Residual Nonfunctioning Pituitary Adenomas
Authors: Pollock Bruce E. , Carpenter Paul C. 
Published: August 2004

Abstract

OBJECTIVE
To evaluate tumor control rates and complications after stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas.

METHODS
Between 1992 and 2000, 33 patients underwent radiosurgery for treatment of nonfunctioning pituitary adenomas. Thirty-two patients (97%) had undergone one or more previous tumor resections. Twenty-two patients (67%) had enlarging tumors before radiosurgery. The median tumor margin dose was 16 Gy (range, 12–20 Gy). The median follow-up period after radiosurgery was 43 months (range, 16–106 mo).

RESULTS
Tumor size decreased for 16 patients, remained unchanged for 16 patients, and increased for 1 patient. The actuarial tumor growth control rates at 2 and 5 years after radiosurgery were 97%. No patient demonstrated any decline in visual function. Five of 18 patients (28%) with anterior pituitary function before radiosurgery developed new deficits, at a median of 24 months after radiosurgery. The actuarial risks of developing new anterior pituitary deficits were 18 and 41% at 2 and 5 years, respectively. No patient developed diabetes insipidus.

CONCLUSION
Stereotactic radiosurgery safely provides a high tumor control rate for patients with recurrent or residual nonfunctioning pituitary adenomas. However, despite encouraging early results, more long-term information is needed to determine whether radiosurgery is associated with lower risks of new endocrine deficits and radiation-induced neoplasms, compared with fractionated radiotherapy.
Hyperperfusion Syndrome: Toward a Stricter Definition
Authors:   For the Calgary Stroke Program, Coutts Shelagh B. , Hill Michael D. , Hu William Y. , Sutherland Garnette R. 
Published: August 2004

AbstractOBJECTIVEHyperperfusion syndrome is a rare and potentially devastating complication of carotid endarterectomy or carotid artery angioplasty and stenting. With the advent of new imaging techniques, we reviewed our experience with this phenomenon.METHODSThis report is a retrospective review of 129 consecutive cases of carotid endarterectomy performed between June 1, 2000, and May 31, 2002, and 44 consecutive cases of carotid artery angioplasty and stenting performed between January 1, 1997, and May 31, 2002. We specifically searched for examples of patients who developed postprocedural nonthrombotic neurological deficits that typified the hyperperfusion syndrome.RESULTSSeven cases of hyperperfusion syndrome occurred, four after endarterectomy (3.1% of carotid endarterectomy cases) and three after stenting (6.8% of stenting cases). The cases of hyperperfusion were classified as presenting with 1) acute focal edema (two cases with stroke-like presentation, attributable to edema immediately after revascularization), 2) acute hemorrhage (two cases of intracerebral hemorrhage immediately after stenting and one case immediately after endarterectomy), or 3) delayed classic presentation (two cases with seizures, focal motor weakness, and/or late intracerebral hemorrhage at least 24 hours after endarterectomy).CONCLUSIONHyperperfusion syndrome may be more common and more variable in clinical presentation than previously appreciated.
Intraoperative Cerebral Angiography: Superficial Temporal Artery Method and Results
Authors: Lee Max C. , Macdonald R. Loch 
Published: August 2004

Abstract

OBJECTIVE
To report the method for and results of intraoperative cerebral angiography performed via the superficial temporal artery, for assessment of cerebral aneurysm surgery.

METHODS
All patients undergoing craniotomies for treatment of intracranial aneurysms were prospectively entered into a database. A policy of performing angiography via the superficial temporal artery in appropriate cases was instituted. This procedure was performed with retrograde catheterization of the superficial temporal artery, as it coursed over the zygomatic arch, with an 18-gauge, 1.88-inch, intravenous catheter and hand injection of contrast material, with intraoperative digital subtraction fluoroscopic guidance.

RESULTS
Thirty-six patients who underwent 38 craniotomies for clipping of 43 aneurysms underwent intraoperative angiography via the superficial temporal artery. There were six unexpected findings (14%), including four unexpected arterial occlusions and two unexpected residual aneurysms. One aneurysm was observed to be patent when it was punctured, after intraoperative angiography had indicated no filling of the aneurysm. Additional clips were placed. Three patients (8%) developed multiple arterial infarctions in the territory of the injected carotid artery, for which multiple causes were possible. Adequate angiographic images could usually be obtained with this method.

CONCLUSION
Intraoperative angiography via the superficial temporal artery is simple and is not associated with substantial complications. It is a reasonable alternative to transfemoral angiography for detection of adverse consequences of intracranial aneurysm clipping.
Management of Acute Cerebellar Infarction: One Institution's Experience
Authors: Raco Antonino , Caroli Emanuela , Isidori Alessandra , Vangelista Tommaso , Salvati Maurizio 
Published: August 2004

Abstract

OBJECTIVE
The management of cerebellar infarctions is controversial. The aim of this study was to determine which patients require surgical treatment and which surgical procedure should be performed when a patient with a cerebellar infarction exhibits progressive neurological deterioration.

METHODS
A total of 44 patients (24 male and 20 female patients; average age, 56 yr) were treated at our institution for cerebellar infarctions in the past 8 years. Twenty-five patients received conservative treatment; two patients who were deeply comatose received no treatment. The remaining 17 patients underwent emergency surgery. Of those 17 patients, 8 underwent external ventricular drainage alone, 5 underwent external ventricular drainage as the first treatment plus secondary suboccipital craniectomy, and 4 underwent suboccipital craniectomy, with removal of necrotic tissue, as the first treatment.

RESULTS
Of the 25 conservatively treated patients, 20 experienced good outcomes, 4 experienced moderate outcomes, and 1 died as a result of pulmonary embolism. Of the 17 surgically treated patients, 10 experienced good functional recoveries (7 treated with external ventricular drainage only and 3 treated with drainage followed by suboccipital craniectomy) and 3 survived with mild neurological deficits (one patient underwent ventriculostomy, one suboccipital craniectomy plus external ventricular drainage, and one suboccipital craniectomy only). The overall mortality rate was 13.6% (6 of 44 patients).

CONCLUSION
For patients with worsening levels of consciousness and radiologically evident ventricular enlargement, we recommend external ventricular drainage. We reserve surgical resection of necrotic tissue for patients whose clinical status worsens despite ventriculostomy, those for whom worsening is accompanied by signs of brainstem compression, and those with tight posterior fossae.
A New Classification for Facial Pain
Authors: Burchiel Kim J. 
Published: August 2004

Abstract

PURPOSE
A patient-oriented classification scheme for facial pains commonly encountered in neurosurgical practice is proposed.

CONCEPT
This classification is driven principally by the patient's history.

RATIONALE
The scheme incorporates descriptions for so-called “atypical” trigeminal neuralgias and facial pains but minimizes the pejorative, accepting that the physiology of neuropathic pains could reasonably encompass a variety of pain sensations, both episodic and constant. Seven diagnostic labels result: trigeminal neuralgia Types 1 and 2 refer to patients with the spontaneous onset of facial pain and either predominant episodic or constant pain, respectively. Trigeminal neuropathic pain results from unintentional injury to the trigeminal nerve from trauma or surgery, whereas trigeminal deafferentation pain results from injury to the nerve by peripheral nerve ablation, gangliolysis, or rhizotomy in an intentional attempt to treat either trigeminal neuralgia or other facial pain. Postherpetic neuralgia follows a cutaneous herpes zoster outbreak (shingles) in the trigeminal distribution, and symptomatic trigeminal neuralgia results from multiple sclerosis. The final category, atypical facial pain, is synonymous with facial pain secondary to a somatoform pain disorder. Atypical facial pain can be suspected but not diagnosed by history and can be diagnosed only with detailed and objective psychological testing.

CONCLUSION
This diagnostic classification would allow more rigorous and objective natural history and outcome studies of facial pain in the future.
Acute Syringomyelia: Case Report
Authors: Milhorat Thomas H. , Bolognese Paolo A. , Black Karen S. , Woldenberg Rona F. 
Published: August 2004

Abstract

OBJECTIVE AND IMPORTANCE
Syringomyelia is generally regarded as a chronic, slowly progressive disorder. We describe a case of acute dilation of the central canal of the spinal cord that presented with rapidly progressive segmental signs.

CLINICAL PRESENTATION
A 29-year-old female patient who had previously undergone surgical treatment for a Chiari I malformation, syringomyelia, and hydrocephalus presented with an 8-day history of headaches, progressive paraparesis, and urinary retention. Magnetic resonance imaging scans demonstrated panventricular hydrocephalus in association with a holocord syrinx that extended to the obex. Magnetic resonance imaging scans that had been coincidentally obtained just 3 days before the onset of symptoms had revealed no evidence of hydrocephalus or syringomyelia.

INTERVENTION
The patient underwent emergency revision of a failed ventriculoperitoneal shunt. Postoperatively, there was prompt resolution of the syringomyelia, hydrocephalus, and associated neurological deficits.

CONCLUSION
Among patients with communicating syringomyelia, the central canal of the spinal cord participates as a “fifth ventricle” and can undergo rapid dilation in association with acute hydrocephalus. Appropriate treatment in such cases involves placement of a ventriculoperitoneal shunt.