bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intra-arterial Third-generation Recombinant Tissue Plasminogen Activator (Reteplase) for Acute Ischemic Stroke
Authors: Qureshi Adnan I. , Ali Zulfiqar , Suri M. Fareed K. , Kim Stanley H. , Shatla Ahmed A. , Ringer Andrew J. , Lopes Demetrius K. , Guterman Lee R. , Hopkins L. Nelson 
Published: July 2004

Abstract

OBJECTIVE
We prospectively evaluated the safety and recanalization efficacy of intra-arterially administered reteplase, a third-generation recombinant tissue plasminogen activator, for treating ischemic stroke in patients considered poor candidates for intravenously administered alteplase therapy.

METHODS
Patients were considered poor candidates for intravenously administered therapy because of severity of neurological deficits, interval from onset of symptoms to presentation of 3 hours or more, or recent major surgery. We administered a maximum total dose of 8 U of reteplase intra-arterially in 1-U increments via superselective catheterization. Adjunctive angioplasty of the occluded artery was performed in seven patients. Angiographic evidence of perfusion and thrombus was graded by use of modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Neurological examinations were performed before and 24 hours and 7 to 10 days after treatment.

RESULTS
Sixteen consecutive patients were treated (mean age, 64.1 ± 16.4 yr; seven were men). Initial National Institutes of Health Stroke Scale scores ranged from 10 to 26. Time from onset of symptoms to treatment ranged from 2 to 9 hours. Occlusion sites were the cervical internal carotid artery (n = 4), intracranial internal carotid artery (n = 4), middle cerebral artery (n = 6), and vertebrobasilar artery (n = 2). Complete or near-complete perfusion (TIMI Grade 3 or 4) was achieved in the arteries in 14 patients (88%), with partial recanalization (TIMI Grade 2) or minimal response (TIMI Grade 1) in the arteries in one patient each. Neurological improvement (defined as decrease of four or more points in National Institutes of Health Stroke Scale score) was observed in 7 (44%) of the 16 patients at 24 hours. Symptomatic intracerebral hemorrhage occurred in one patient; three other patients experienced intracerebral hemorrhages that did not result in neurological worsening. The overall mortality during hospitalization was 56%, related to massive ischemic stroke (n = 7), withdrawal of care at the family's request after the development of aspiration pneumonia and renal failure (n = 1), and a combination of intracerebral hemorrhage and massive ischemic stroke (n = 1).

CONCLUSION
In this study, intra-arterially administered reteplase in doses up to 8 U with or without angioplasty resulted in a high rate of recanalization. This strategy should be considered in treating patients considered poor candidates for intravenous thrombolysis.
C1–C2 Transarticular Screw Fixation: Technical Aspects
Authors: Haid Regis W. 
Published: July 2004

Abstract

OBJECTIVE
I review posterior atlantoaxial fusion with transarticular screw fixation, including indications, complications, and operative technique, emphasizing my experience.

METHODS
The indications for C1–C2 transarticular screw fixation include traumatic injuries to the atlantoaxial complex, instability resulting from inflammatory disease (rheumatoid arthritis), and congenital abnormalities (os odontoideum). All patients underwent stabilization using cannulated C1–C2 transfacetal screws by the method described by Magerl. Supplemental interspinous fusion with bicortical autologous iliac crest graft and titanium cable was used to restore the posterior tension band by use of the method described by Sonntag's group. Preoperatively, all patients underwent imaging with plain radiographs, magnetic resonance imaging, and axial computed tomography. Patients were maintained in a rigid cervical orthosis postoperatively.

RESULTS
Measures used to improve safety and efficacy include patient positioning, fluoroscopic guidance, preoperative magnetic resonance imaging, axial computed tomography, and open reduction of C1–C2 subluxation before screw passage. In this series of 75 patients, fusion was obtained in 72 patients (96%). There were no instances of vertebral artery injury, errant screw placement, instrumentation failure, dural laceration, spinal cord injury, or hypoglossal nerve injury.

CONCLUSION
C1–C2 transarticular screw fixation with a posterior tension band construct provides excellent fusion rates with few perioperative complications. Preoperative imaging and meticulous surgical technique improve outcomes.
Management of Cysts Arising after Radiosurgery to Treat Intracranial Arteriovenous Malformations
Authors: Pollock Bruce E. , Brown Robert D. 
Published: July 2004

Abstract

OBJECTIVE
The proper treatment for patients with cyst formation after arteriovenous malformation radiosurgery is unknown.

METHODS
The treatment of six patients who developed cysts after arteriovenous malformation radiosurgery is described. Four patients had undergone gamma knife radiosurgery (two patients developed cysts after repeat procedures), and two patients had undergone linear accelerator-based radiosurgery. The median prescription isodose volume at the time of the first radiosurgical procedure was 13.2 cm3 (range, 8.0–28.7 cm3).

RESULTS
The cysts were discovered a median of 48 months (range, 24–89 mo) after radiosurgery. Three patients were originally without symptoms, and observation with serial imaging was performed; two of those patients developed symptoms 13 and 40 months later, whereas one patient has remained without symptoms for 51 months. Initial treatments for patients with symptomatic cysts included cyst aspiration (n = 3) and placement of a cystoperitoneal shunt (CPS) (n = 2). The median cyst volume was 14 cm3 (range, 4–63 cm3). Cyst recurrence occurred within 2 months for patients who underwent aspiration alone, necessitating placement of a CPS. Shunt placement eliminated the cysts for four patients, at a median follow-up time of 16 months (range, 9–27 mo). One patient's cyst persisted despite CPS placement, and cyst excision was performed. No morbidity occurred with any of the cyst treatments.

CONCLUSION
Cyst formation after arteriovenous malformation radiosurgery may occur many years after the procedure. Although most symptomatic cysts can be effectively treated with CPSs, cyst excision may be necessary if the mass effect is not relieved with the less invasive approach.
Electrical Stimulation of the Prelemniscal Radiation in the Treatment of Parkinson's Disease: An Old Target Revised with New Techniques
Authors: Velasco Francisco , Jiménez Fiacro , Pérez Martha Luisa , Carrillo-Ruiz José D. , Velasco Ana Luisa , Ceballos Joel , Velasco Marcos 
Published: July 2004

Abstract

OBJECTIVE
In the treatment of tremor and rigidity in patients with Parkinson's disease (PD), the prelemniscal radiation (RAPRL), a subthalamic bundle of fibers, is an exquisite target that can be visualized easily on ventriculograms. We sought to evaluate the effect of electrical stimulation of the RAPRL on symptoms and signs of PD in a long-term trial and to determine the localization of the stimulated area by means of stereotactic magnetic resonance imaging studies.

METHODS
Ten patients with PD predominantly on one side had tetrapolar electrodes stereotactically oriented through a frontal parasagittal approach to the RAPRL contralateral to the most prominent symptoms. Preoperative and postoperative evaluations at 3, 6, 9, and 12 months after surgery were performed using conventional PD scales and quantitative evaluations of tremor amplitude and reaction time. Stereotactic high-resolution magnetic resonance imaging studies with the electrodes in place were used for anatomic localization.

RESULTS
In all patients, temporary suppression of tremor occurred when the electrodes reached the target. The most effective stimulation was obtained when the pair of contacts was placed in the RAPRL. Long-term stimulation at 130 Hz, 0.09 to 0.450 milliseconds, and 1.5 to 3.0 V produced significant improvement in tremor and rigidity and mild improvement in bradykinesia.

CONCLUSION
The RAPRL is an effective target for the alleviation of tremor and rigidity in patients with PD by either lesioning or neuromodulation; however, neuromodulation has the advantage of not inducing an increase in bradykinesia. The stimulated area seems to be independent of the subthalamic nucleus.
Deep Brain Stimulator Electrodes Used for Lesioning: Proof of Principle
Authors: Oh Michael Y. , Hodaie Mojgan , Kim Seong Ho , Alkhani Ahmed , Lang Anthony E. , Lozano Andres M. 
Published: July 2004

Abstract

OBJECTIVE
Patients with chronically implanted deep brain stimulator (DBS) electrodes can encounter complications requiring hardware removal. We assessed the safety and efficacy of using implanted DBS electrodes to create a therapeutic lesion before their removal.

METHODS
Revision or removal of the DBS electrodes was required in two patients who had previously undergone DBS implantation. We conducted a series of in vitro experiments to confirm that the DBS electrodes could be used to generate radiofrequency lesions and to assess the relationship between radiofrequency parameters and lesion size. With this information, and with the approval of the hospital ethical review board, implanted electrodes were used to create incremental radiofrequency lesions in the thalamus in one patient and in the subthalamic nucleus in another. The procedures were performed under local anesthesia with contiguous contacts of the DBS lead connected to the active and reference sites of the RF generator to create a bipolar lesion.

RESULTS
A 51-year-old man with essential tremor and a thalamic DBS required repeated battery changes secondary to tolerance and high voltage demands. Rather than replacing the battery, a radiofrequency thalamotomy was performed by using the existing left DBS electrode. At the 6-month follow-up examination, successful lesioning provided near complete tremor control. A second patient, a 50-year-old man with Parkinson's disease who had undergone bilateral subthalamic deep brain stimulation, developed skin erosion over the DBS hardware. A subthalamic nucleus lesion was made through the right DBS electrode. Lesion position and size were confirmed with magnetic resonance imaging.

CONCLUSION
Lesions can be made through chronically implanted DBS electrodes in a safe, graded fashion and can produce therapeutic benefit.
Surgical Exposure and Resection of the Vertical Portion of the Petrous Internal Carotid Artery: Anatomic Study
Authors: Suhardja Agustinus S. , Cusimano Michael D. , Agur Anne M.R. 
Published: July 2004

AbstractOBJECTIVEThe goals were to determine which surgical approaches, i.e., the preauricular subtemporal infratemporal fossa (PSI), postauricular transtemporal (PAT), and/or subtemporal middle fossa (SMF) approaches, provide optimal exposure of the anterior, posterior, medial, and lateral aspects of the vertical segment of the petrous internal carotid artery (VPCA) and to determine the length of the VPCA that can be resected before a vein graft is necessary.METHODSUsing 22 cadaveric specimens, we compared the length of exposure of the VPCA provided by the PSI, PAT, and SMF approaches. The segment of the VPCA that was exposed with each approach was measured in millimeters and expressed as a percentage of the total length of the VPCA. Resection of the VPCA in 1-mm increments was performed until a graft would be necessary; the total length of the resected segment was recorded in millimeters and was also expressed as a percentage of the total length of the VPCA.RESULTSThe PSI approach provided average exposures of 14.1 mm (95% of the total exposure possible) of the anterior aspect and 14.3 mm (96%) of the lateral aspect of the VPCA; resection of less than 2.3 mm (16%) of the VPCA could be repaired with an end-to-end anastomosis. The PAT approach provided average exposures of 10.5 mm (71%) of the lateral aspect and 10.0 mm (76%) of the posterior aspect of the VPCA; resection of less than 2.8 mm of the VPCA could be repaired with an end-to-end anastomosis. The SMF approach provided average exposures of 6.1 mm (45%) of the anterior aspect and 5.4 mm (41%) of the lateral aspect of the VPCA; resection of less than 2.4 mm (24%) of the VPCA could be repaired with an end-to-end anastomosis.CONCLUSIONLesions on the anterior and lateral aspects of the VPCA can be fully exposed with the PSI approach or partially exposed with the less invasive SMF approach. Lesions on the posterior aspect of the artery are best exposed with the PAT approach. Lesions on the medial aspect of the VPCA cannot be exposed unless the VPCA is mobilized in the PSI approach. Resection of less than approximately 2.5 mm (20%) can be repaired with an end-to-end anastomosis, regardless of the approach used.
Focal Intracranial Infections Due to Propionibacterium acnes: Report of Three Cases
Authors: Chu Ray M. , Tummala Ramachandra P. , Hall Walter A. 
Published: July 2004

Abstract

OBJECTIVE AND IMPORTANCE
Except for its role in shunt infections, Propionibacterium acnes has been of little interest to neurosurgeons. The rarity and indolent nature of focal intracranial infections by P. acnes limit their recognition. Three cases of serious intracranial infection due to this organism are described.

CLINCAL PRESENTATION
Three patients with histories of immunosuppression and neurosurgical procedures developed nonspecific, delayed presentations (5 wk to 5 yr after surgery) of intracranial infections. In two patients, radiological investigations showed enhancing lesions that were later found to be brain abscesses. A subdural empyema was found in the third patient.

INTERVENTION
All three patients underwent surgical drainage of the purulent collections. P. acnes was isolated in each case, and each patient was treated with a 6-week course of intravenous penicillin. All three patients made good recoveries, and subsequent imaging showed no recurrence of the infectious collections.

CONCLUSION
P. acnes is an indolent organism that may rarely cause severe intracranial infections. This organism should be suspected when an intracranial purulent collection is discovered in a patient with a history of neurosurgical procedures. Immunosuppressed patients may be susceptible to this otherwise benign organism. Surgical drainage and treatment with intravenous penicillin should be considered standard therapy.
M2/M2 Side-to-Side Rescue Anastomosis for Accidental M2 Trunk Occlusion during Middle Cerebral Artery Aneurysm Clipping: Technical Note
Authors: Steiger Hans-Jakob , Ito Seiro , Schmid-Elsässer Robert , Uhl Eberhard 
Published: July 2004

Abstract

OBJECTIVE
A technically feasible and rapid technique for revascularizing the main branches of the middle cerebral artery (MCA) is described. This technique is applied mainly when clipping of an MCA aneurysm is complicated and occlusion of the origin of an MCA main branch results.

METHODS
M2/M2 side-to-side anastomosis was applied in two patients in whom unplanned M2 occlusion occurred during the course of complicated MCA aneurysm clipping. The first patient underwent an emergency procedure after temporoparietal intracerebral hemorrhage. Unilateral mydriasis precluded preoperative angiographic workup, and a complex large MCA aneurysm was found as the source of hemorrhage. Shaping of the aneurysm neck by bipolar coagulation and clipping resulted in accidental occlusion of the superior trunk, and patency could not be regained despite multiple clip corrections. The second patient had an unruptured multilobulated aneurysm 8 mm in maximum diameter. Continuity of the inferior trunk was lost during clipping because of a tear at the origin. In both instances, side-to-side anastomosis was placed approximately 15 mm from the bifurcation, where the MCA main trunks ran side by side for a length of approximately 5 mm.

RESULTS
After intracerebral hemorrhage, the first patient recovered to a level of moderate disability within 2 months. Substantial hemiparesis and expressive dysphasia remained as sequelae of the intracerebral hemorrhage. Digital subtraction angiography 2 months after the emergency procedure confirmed patency of the side-to-side anastomosis. The second patient was neurologically intact after recovery from anesthesia. Before discharge from the hospital on postoperative Day 8, digital subtraction angiography confirmed patency of the anastomosis.

CONCLUSION
The MCA main branches usually run in close proximity for a short segment at the bottleneck entrance to the insular cistern. M2/M2 side-to-side anastomosis at this site is a rapid and feasible mode of revascularization of an M2 trunk accidentally occluded during complicated MCA aneurysm clipping.
Quantitative Analysis of the Transcondylar Approach to the Foramen Magnum
Authors: Wanebo John E. , Chicoine Michael R. 
Published: July 2004

Abstract

OBJECTIVE
Condylar resection with suboccipital craniotomy increases foramen magnum exposure, but guidelines for when this is necessary are not defined. Cadaveric and computed tomography evaluations were completed to guide decision-making regarding the use and extent of condylar resection.

METHODS
Quantitative analysis of foramen magnum surgical exposures was performed on 32 skulls (64 sides) and 6 cadaveric dissections (12 sides). Computed tomographic (CT) scans were performed on cadaveric heads before and after condylar resections. Digitized images of dry skulls and CT images of cadaver heads were quantitatively analyzed. Predissection CT measurements of cadaveric heads guided extent of condylar resections, and resection accuracy was assessed with postdissection CT scans.

RESULTS
Skull measurements (means in parentheses) included the foramen magnum area (7.8 cm2), length (3.6 cm), width (3.1 cm), anteroposterior condylar length (2.3 cm), and axial condylar length (2.5 cm). Mean widths of potential surgical exposures for skulls were obtained for A) suboccipital craniotomy (2.3 cm), B) with 25% (2.6 cm), and C) 50% condylar resection (3.0 cm). Mean angles of exposure were as follows: A, 38.4 degrees; B, 49.1 degrees; and C, 54.3 degrees. CT scans of cadaveric heads before and after dissections yielded measurements of exposure equivalent to measurements found on the dry skulls.

CONCLUSION
On average, lateral exposure increases by 3 mm (13%) and 7 mm (30%) for 25 and 50% condylar resection, respectively, compared with suboccipital craniotomy alone. Angles of exposure increase by 10.7 degrees (28%) and 15.9 degrees (41%). Measurements of CT images can be used preoperatively to help analyze the need for condylar resection and intraoperatively to guide the extent of condylar resection.
Association between Intracranial Plasmacytoma and Multiple Myeloma: Clinicopathological Outcome Study
Authors: Schwartz Theodore H. , Rhiew Richard , Isaacson Steven R. , Orazi Attilio , Bruce Jeffrey N. 
Published: July 2004

ABSTRACTOBJECTIVEIntracranial plasmacytomas are rare lesions that can arise from the calvarium, dura, or cranial base and exhibit a benign course unless associated with myeloma. Attention has recently been focused on the role of the cell adhesion molecules CD56 and CD31 in the pathogenesis of myeloma. No such information is available for intracranial plasmacytomas and myeloma-associated lesions.METHODSWe investigated the relationship between CD56 and CD31 expression, intracranial location, and progression to myeloma for a series of nine intracranial plasmacytomas (three dural, one calvarial, and five cranial base lesions). These parameters were also correlated with proliferation indices, as assessed by MIB-1 immunostaining of the histological sections. A single pathologist (AO) performed immunohistochemical analyses and reviewed all slides.RESULTSIntracranial plasmacytomas presented more commonly in female patients (89%). The three dural lesions were CD56- and CD31-negative and exhibited MIB-1 staining of less than 10%; no patient developed myeloma or recurrence. Of the five cranial base lesions, three were CD56-positive, none was CD31-positive, and two exhibited MIB-1 labeling of more than 45%, with plasmablastic morphological features. Compared with other intracranial plasmacytomas, five of five patients with cranial base lesions developed bone marrow biopsy-proven myeloma (P &lt; 0.05) within 8 months. The calvarial lesion was CD56- and CD31-positive, and the patient developed myeloma soon after diagnosis. Both of the two highly proliferative plasmablastic lesions recurred, one after gross total resection without radiotherapy and the other after a biopsy and 2000-cGy radiotherapy.CONCLUSIONAmong intracranial plasmacytomas, cranial base location was the strongest predictor of the development of multiple myeloma. Expression of the cell adhesion molecules CD31 and CD56 was not predictive of outcome. Extramedullary dural-based lesions were CD56-negative and were not associated with myeloma. A high proliferation index and plasmablastic morphological features were predictive of a short time to recurrence and aggressive behavior. We recommend 4050- to 5040-cGy fractionated radiotherapy for all intracranial plasma cell neoplasms and gross total resection for non-cranial base lesions.
Association of Chiari I Malformation, Mental Retardation, Speech Delay, and Epilepsy: A Specific Disorder?
Authors: Grosso Salvatore , Scattolini Roberto , Paolo Galluzzi , Di Bartolo Rosanna Maria , Morgese Guido , Balestri Paolo 
Published: July 2004

ABSTRACT

OBJECTIVE
The Chiari I malformation is defined as tonsillar herniation of at least 3 to 5 mm below the foramen magnum. Although Chiari I malformation is considered to derive from a mesodermal disorder resulting in underdevelopment of the posterior fossa relative to its content, evidence for a possible heterogeneous etiology also has been reported. The aim of the present study is to elucidate the relationship between Chiari I malformation and mental retardation, speech delay, and epilepsy to consider a possible specific pathogenetic background.

METHODS
Thirty-five patients with Chiari I malformations were identified by use of magnetic resonance imaging during a period between 1993 and 1999. The study consisted of nine patients (four boys and five girls) who were affected by mental retardation, speech delay, and epilepsy. All patients underwent electroencephalography and brain and cervical spine magnetic resonance imaging.

RESULTS
All patients were mentally retarded with a mean intelligence quotient of 50. Seven patients had a positive history for speech delay, and five were epileptic. Electroencephalograms demonstrated abnormalities in seven patients. The mean tonsillar displacement was 10.1 mm. A thin corpus callosum and a wide cavum septum pellucidum were present in three patients. Neither hydromyelia nor scoliosis was observed. No correlation between the degree of the ectopia and clinical manifestation was noted.

CONCLUSION
The association of Chiari I malformation with epilepsy, speech delay, and mental retardation may not be a mere incidental finding but may be a marker for a different pathogenetic background.