bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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

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

OBJECTIVE

Hyperperfusion 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.

METHODS

This 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.

RESULTS

Seven 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).

CONCLUSION

Hyperperfusion 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

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

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

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

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.
Surgical Outcomes of 111 Spinal Accessory Nerve Injuries
Authors: Kim Daniel H. , Cho Yong-Jun , Tiel Robert L. , Kline David G.
Published: August 2004

OBJECTIVE

Iatrogenic injury to the spinal accessory nerve is not uncommon during neck surgery involving the posterior cervical triangle, because its superficial course here makes it susceptible. We review injury mechanisms, operative techniques, and surgical outcomes of 111 surgical repairs of the spinal accessory nerve.

METHODS

This retrospective study examines clinical and surgical experience with spinal accessory nerve injuries at the Louisiana State University Health Sciences Center during a period of 23 years (1978–2000). Surgery was performed on the basis of anatomic and electrophysiological findings at the time of operation. Patients were followed up for an average of 25.6 months.

RESULTS

The most frequent injury mechanism was iatrogenic (103 patients, 93%), and 82 (80%) of these injuries involved lymph node biopsies. Eight injuries were caused by stretch (five patients) and laceration (three patients). The most common procedures were graft repairs in 58 patients. End-to-end repair was used in 26 patients and neurolysis in 19 patients if the nerve was found in continuity with intraoperative electrical evidence of regeneration. Five neurotizations, two burials into muscle, and one removal of ligature material were also performed. More than 95% of patients treated by neurolysis supported by positive nerve action potential recordings improved to Grade 4 or higher. Of 84 patients with lesions repaired by graft or suture, 65 patients (77%) recovered to Grade 3 or higher. The average graft length was 1.5 inches.

CONCLUSION

Surgical exploration and repair of spinal accessory nerve injuries is difficult. With perseverance, however, these patients with complete or severe deficits achieved favorable functional outcomes through operative exploration and repair.
Microsurgical Keyhole Approach for Middle Fossa Arachnoid Cyst Fenestration
Authors: Levy Michael L. , Wang Michael , Aryan Henry E. , Yoo Kevin , Meltzer Hal
Published: August 2004

OBJECTIVE

The optimal surgical treatment for symptomatic temporal arachnoid cysts is controversial. Therapeutic options include cyst shunting, endoscopic fenestration, and craniotomy for fenestration. We reviewed the results for patients who were treated primarily with craniotomy and fenestration at our institution, to provide a baseline for comparisons of the efficacies of other treatment modalities.

METHODS

A retrospective review of data for 50 children who underwent keyhole craniotomy for fenestration of temporal arachnoid cysts between 1994 and 2001 was performed after institutional review board approval. During that period, the first-line treatment for all symptomatic middle fossa arachnoid cysts was microcraniotomy for fenestration. Microsurgical dissection to create communications between the cyst cavity and basal cisterns was the goal. All patient records were reviewed and numerous variables related to presentation, cyst size and classification, treatment, cyst resolution, symptom resolution, follow-up periods, and cyst outcomes were recorded.

RESULTS

Fifty temporal arachnoid cysts in 50 treated patients were identified. The average age at the time of surgery was 68 ± 57.2 months. The follow-up periods averaged 36 months. There were 34 male and 16 female patients in the series. Twenty-six cysts were on the left side. Indications for surgery included intractable headaches (45%), increasing cyst size (21%), seizures (25%), and hemiparesis (8%). The symptoms most likely to improve were hemiparesis (100%) and abducens nerve palsies. Headaches (67%) and seizure disorders (50%) were less likely to improve. Nine patients exhibited progressive increases in cyst size in serial imaging studies. Those patients were monitored for a mean of 40 ± 23 months before intervention. In the entire series, 82% of patients demonstrated decreases in cyst size in serial imaging studies. Of those patients, 18% demonstrated complete cyst effacement. Overall, 83% of patients with Grade II cysts and 75% of patients with Grade III cysts exhibited evidence of decreases in cyst size in long-term monitoring. Two patients required shunting after craniotomy (4%). Hospital stays averaged 3.4 days. Total surgical times averaged 115 minutes. No significant blood loss occurred (5–50 ml). Complications included spontaneously resolving pseudomeningocele (10%), transient Cranial Nerve III palsy (6%), cerebrospinal fluid leak (6%), subdural hematoma (4%), and wound infection (2%).

CONCLUSION

A microsurgical keyhole approach to arachnoid cyst fenestration is a safe effective method for treating middle fossa cysts. This procedure can be performed with minimal morbidity via a minicraniotomy. Compared with an endoscopic approach, better control of hemostasis can be obtained, because of the ability to use bipolar forceps and other standard instruments. The operative time and length of hospital stay were not excessively increased.
Implantation of Laminotomy Electrodes for Spinal Cord Stimulation in Spinal Anesthesia with Intraoperative Dorsal Column Activation
Authors: Lind Göran , Meyerson Björn A. , Winter Jaleh , Linderoth Bengt
Published: August 2004

OBJECTIVE

To optimize the technique of implanting laminotomy plate electrodes for spinal cord stimulation and to minimize the discomfort of the patients during surgery. This operation is often performed while the patient is under local anesthesia, which is very stressful for the patient, or under general anesthesia, which precludes the use of test stimulation. An alternative approach is to perform the implantation with a spinal anesthetic and to examine whether stimulation-induced paresthesiae can still be evoked to guide the positioning of the electrode.

METHODS

Spinal anesthesia was induced by bupivacaine (12.5–20 mg), which produced complete motor block and anesthesia up to a midthoracic level. After a single-level laminotomy (thoracic vertebrae 9–11) a four-pole plate electrode was inserted into the epidural space. Stimulation was applied with commonly used parameters, and the electrode was positioned so that the paresthesiae covered the painful region.

RESULTS

In 19 patients (20 procedures) with different forms of neuropathic pain, implantation of laminotomy plate electrodes could be performed under spinal anesthesia without problems. In all patients, it was possible to evoke paresthesiae, the distribution of which could be reproduced postoperatively. The paresthesia thresholds during surgery were only moderately higher than those recorded after implantation (mean, 3.1 versus 2.1 V, respectively). During an interview after the intervention, no patient reported that he or she had experienced surgery as painful or uncomfortable.

CONCLUSION

Implantation of laminotomy electrodes can be performed conveniently with spinal anesthesia because it minimizes discomfort for the patient and enables the use of intraoperative test stimulation to guide the positioning of the electrode. In spite of the total motor block and anesthesia, paresthesiae representing the activation of the dorsal columns can be evoked and are well perceived, and the thresholds are not abnormally high. This observation supports the notion that the subarachnoidal anesthetic agent acts predominantly on the spinal rootlets rather than on the spinal afferent pathways.
Recurrent Spontaneous Spinal Cerebrospinal Fluid Leak Associated with “Nude Nerve Root” Syndrome: Case Report
Authors: Schievink Wouter I. , Jacques Line
Published: August 2004

OBJECTIVE AND IMPORTANCE

Spontaneous spinal cerebrospinal fluid (CSF) leaks have been noted occasionally at multiple sites in the same patient, but recurrent spontaneous spinal CSF leaks have not been documented. We describe a patient with a recurrent CSF leak who was found at surgery to have an absence of the entire nerve root sleeve at multiple thoracic levels.

CLINICAL PRESENTATION

A 29-year-old woman bodybuilder noted an excruciating orthostatic headache associated with nausea. The neurological examination was unremarkable, and a magnetic resonance imaging examination showed the typical changes of intracranial hypotension. Computed tomographic myelography showed an extensive bilateral lower cervical CSF leak.

INTERVENTION

The patient underwent bilateral lower cervical nerve root explorations, and several small dural holes were found. The CSF leaks were repaired, but 3 months later, computed tomographic myelography showed a new CSF leak in the midthoracic area. A thoracic laminectomy was performed, and several nerve roots were found to be completely devoid of dura. After the CSF leaks were repaired, there was significant improvement in her headaches.

CONCLUSION

A recurrent spontaneous spinal CSF leak may occur in patients with intracranial hypotension at a site previously documented not to be associated with a CSF leak. Absent nerve root sleeves may be found in patients with spontaneous spinal CSF leaks (“nude nerve root” syndrome), and these patients may be at increased risk of developing a recurrent CSF leak.
The CyberKnife Stereotactic Radiosurgery System: Description, Installation, and an Initial Evaluation of Use and Functionality
Authors: Kuo John S. , Yu Cheng , Petrovich Zbigniew , Apuzzo Michael L.J.
Published: August 2004

The CyberKnife Stereotactic Radiosurgery System is manufactured by Accuray, Inc. (570 Del Rey Avenue, Sunnyvale, CA 94085; telephone 1-888/522-3740 or 1-408/522-3740; http://www.accuray.com). It is currently available for purchase (capital cost of US $3.2 million plus US $0.5 to 0.75 million for site setup), or in a revenue-sharing plan (US $0.5 to 0.75 million setup cost). FIGURE
Treatment of Thoracolumbar Burst Fractures with Polymethyl Methacrylate Vertebroplasty and Short-segment Pedicle Screw Fixation
Authors: Cho Der-Yang , Lee Wuen-Yen , Sheu Pon-Chun
Published: August 2004

OBJECTIVES

We aimed to evaluate the efficacy of reinforcing short-segment pedicle screw fixation with polymethyl methacrylate (PMMA) vertebroplasty in patients with thoracolumbar burst fractures.

METHODS

We enrolled 70 patients with thoracolumbar burst fractures for treatment with short-segment pedicle screw fixation. Fractures in Group A (n = 20) were reinforced with PMMA vertebroplasty during surgery. Group B patients (n = 50) were not treated with PMMA vertebroplasty. Kyphotic deformity, anterior vertebral height, instrument failure rates, and neurological function outcomes were compared between the two groups.

RESULTS

Kyphosis correction was achieved in Group A (PMMA vertebroplasty) and Group B (Group A, 6.4 degrees; Group B, 5.4 degrees). At the end of the follow-up period, kyphosis correction was maintained in Group A but lost in Group B (Group A, 0.33-degree loss; Group B, 6.20-degree loss) (P = 0.0001). After surgery, greater anterior vertebral height was achieved in Group A than in Group B (Group A, 12.9%; Group B, 2.3%) (P < 0.001). During follow-up, anterior vertebral height was maintained only in Group A (Group A, 0.13 ± 4.06%; Group B, −6.17 ± 1.21%) (P < 0.001). Patients in both Groups A and B demonstrated good postoperative Denis Pain Scale grades (P1 and P2), but Group A had better results than Group B in terms of the control of severe and constant pain (P4 and P5) (P < 0.001). The Frankel Performance Scale scores increased by nearly 1 in both Groups A and B. Group B was subdivided into Group B1 and B2. Group B1 consisted of patients who experienced instrument failure, including screw pullout, breakage, disconnection, and dislodgement (n = 11). Group B2 comprised patients from Group B who did not experience instrument failure (n = 39). There were no instrument failures among patients in Group A. Preoperative kyphotic deformity was greater in Group B1 (23.5 ± 7.9 degrees) than in Group B2 (16.8 ± 8.40 degrees), P < 0.05. Severe and constant pain (P4 and P5) was noted in 36% of Group B1 patients (P < 0.001), and three of these patients required removal of their implants.

CONCLUSION

Reinforcement of short-segment pedicle fixation with PMMA vertebroplasty for the treatment of patients with thoracolumbar burst fracture may achieve and maintain kyphosis correction, and it may also increase and maintain anterior vertebral height. Good Denis Pain Scale grades and improvement in Frankel Performance Scale scores were found in patients without instrument failure (Groups A and B2). Patients with greater preoperative kyphotic deformity had a higher risk of instrument failure if they did not undergo reinforcement with vertebroplasty. PMMA vertebroplasty offers immediate spinal stability in patients with thoracolumbar burst fractures, decreases the instrument failure rate, and provides better postoperative pain control than without vertebroplasty.
Failure of Intraoperative Jugular Bulb S-100B and Neuron-Specific Enolase Sampling to Predict Cognitive Injury after Carotid Endarterectomy
Authors: Sahlein Daniel H. , Heyer Eric J. , Rampersad Anita , Winfree Christopher J. , Solomon Robert A. , Benvenisty Alan I. , Quest Donald O. , Du Evelyn , Connolly E. Sander
Published: August 2004

OBJECTIVE

Cognitive decline occurs in 25% of patients after carotid endarterectomy (CEA). Elevated serum concentrations of S-100B and neuron-specific enolase (NSE) occur after stroke, and serum S-100B levels at 24 hours are associated with clinical outcome after both stroke and CEA. We hypothesized that we could detect acute elevations in serum levels of these markers obtained intraoperatively from the jugular bulb (JB) and that these elevations would predict cognitive dysfunction postoperatively as measured by neuropsychometric test performance.

METHODS

Forty-three patients scheduled for elective CEA were assessed with a battery of neuropsychometric tests before and 1 day after surgery. Before the carotid artery was clamped, a 6-French Fogarty catheter was inserted into the facial vein and threaded 6 cm rostrally into the JB. Serum samples were withdrawn from this catheter and simultaneously from a radial arterial catheter (A-line) at three time points: before clamping, 15 minutes into clamping, and after unclamping the carotid artery. Concentrations between groups were compared by analysis of variance and paired t tests.

RESULTS

Total deficit scores were significantly worse in 13 (30%) of the 43 patients 1 day after surgery. There was a trend toward elevations in JB concentrations of S-100B relative to A-line levels 15 minutes after cross-clamping (11% elevation, P = 0.079, paired t test). In addition, 15 minutes after clamping of the carotid artery, levels of S-100B from the JB were significantly elevated compared with levels at baseline (P = 0.040, one-way analysis of variance). No significant changes were found between any time point in levels of S-100B from the A-line blood or of NSE from either the JB or the A-line. Subtle cognitive decline after CEA was not correlated with intraoperative levels of S-100B or NSE, but there was a weak, statistically nonsignificant, association between a rise in 15-minute S-100B levels and cognitive injury that was not seen with JB samples.

CONCLUSION

Although intraoperative levels of S-100B and NSE from the JB failed to predict cognitive injury, carotid cross-clamping, independent of injury, seems to be associated with early elevations in S-100B.
Image-guided Transsylvian, Transinsular Approach for Insular Cavernous Angiomas
Authors: Tirakotai Wuttipong , Sure Ulrich , Benes Ludwig , Krischek Boris , Bien Siegfried , Bertalanffy Helmut
Published: August 2004

OBJECTIVE

Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness.

METHODS

Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient.

RESULTS

The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients.

CONCLUSION

Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.
Treatment of Intramedullary Hemangioblastomas, with Special Attention to von Hippel-Lindau Disease
Authors: Van Velthoven Vera , Reinacher Peter C. , Klisch Joachim , Neumann Hartmut P.H. , Gläsker Sven
Published: August 2004

OBJECTIVE

Hemangioblastomas of the central nervous system are rare vascular tumors that can occur as sporadic lesions or as component tumors of autosomal dominant von Hippel-Lindau disease. With the availability of magnetic resonance imaging, asymptomatic tumors are detected more frequently, especially among patients with von Hippel-Lindau disease, and the questions of whether and when these lesions should be treated arise. To identify surgical outcomes and the timing of surgery for intramedullary hemangioblastomas, we retrospectively analyzed data for a series of 28 consecutive patients whom we surgically treated for intramedullary hemangioblastomas in the past 10 years.

METHODS

All tumors were completely removed. Functional grades, according to the McCormick scale, were determined before and after surgery and in follow-up assessments. Several clinical characteristics were correlated with changes in functional grades in follow-up assessments, compared with preoperative grades.

RESULTS

Functional grades in follow-up assessments improved for 28.6% of the patients and remained unchanged for 71.4%. No patient was in worse condition, compared with preoperative status. Peritumoral edema on preoperative magnetic resonance imaging scans was correlated with significantly higher surgical morbidity rates. Four asymptomatic patients were surgically treated because of tumor or pseudocyst progression on serial magnetic resonance imaging scans. All of those patients remained asymptomatic postoperatively.

CONCLUSION

Intramedullary hemangioblastomas can be removed with low surgical morbidity rates and excellent long-term prognoses. The timing of surgery for patients with von Hippel-Lindau disease and multiple lesions remains a matter of debate. On the basis of our data, we established the strategy of operating also on asymptomatic lesions that exhibit radiological progression, before significant neurological deficits occur, which are often not reversible.
Pseudohypoxic Brain Swelling: A Newly Defined Complication after Uneventful Brain Surgery, Probably Related to Suction Drainage
Authors: Van Roost Dirk , Thees Christof , Brenke Christopher , Oppel Falk , Winkler Peter A. , Schramm Johannes
Published: August 2004

OBJECTIVE

This is the first description of a severe and sometimes fatal complication after uneventful intracranial surgery. The clinical presentation and imaging features mimic those of global cerebral hypoxia. Extensive investigations were performed to discover the pathogenesis.

METHODS

Seventeen cases of pseudohypoxic brain swelling (PHBS) were collected from our institution and from various other neurosurgical departments and were studied for common features. PHBS can occur in a mild, moderate, or severe degree. It is characterized by a very early postoperative onset of clinical deterioration (clouded or lost consciousness and pupillary abnormalities), in association with typical bilateral computed tomographic or magnetic resonance imaging changes (hypodensities or altered intensities in the basal ganglia and/or thalamus). The following variables were considered: age, primary pathological lesion and intracranial location, previous cranial surgery, anesthetic risk, type of anesthesia, approach and duration of surgery, intraoperative observations, technical monitoring results, and blood gas analyses. The results of postoperative computed tomography and various other imaging studies, intracranial pressure measurements, transcranial Doppler sonography, toxicological analyses, brain and muscle biopsies, and autopsies were also considered in the investigation. Several countermeasures were instituted and evaluated.

RESULTS

Anoxemic and ischemic hypoxia was excluded as a cause of PHBS. No evidence was found for inhibition of the respiratory chain, mitochondriopathy, poisoning, or adverse effects of drugs.

CONCLUSION

Indications of intracranial hypotension, induced by suction drainage, being the main pathomechanism of PHBS are discussed. A serious warning is issued regarding the use of suction drainage after intracranial surgery.
Suprasellar Displacement of Intracavernous Internal Carotid Artery: Case Report
Authors: Gottfried Oren N. , Soleau Scott W. , Couldwell William T.
Published: August 2004

OBJECTIVE AND IMPORTANCE

We present a previously undescribed variant of the cavernous internal carotid artery (ICA) and review the literature concerning other variants of the cavernous ICA.

CLINICAL PRESENTATION

The patient, a 53-year-old woman with fibromuscular dysplasia and multiple intracranial aneurysms, underwent cerebral angiography in preparation for clipping of a terminal ICA bifurcation aneurysm that demonstrated a redundant loop of the cavernous ICA abutting the supraclinoid carotid artery.

INTERVENTION

The patient underwent a pterional craniotomy to approach a terminal ICA bifurcation aneurysm. During the procedure, an unexpected vascular anomaly was discovered. On further dissection, we confirmed that the vascular abnormality was a segment of the ICA that had herniated through the superomedial cavernous sinus wall.

CONCLUSION

This case demonstrates that the cavernous ICA may become dehiscent from the cavernous sinus wall and herniate into the suprasellar space. Knowledge and anticipation of anatomic variants of the cavernous carotid artery are essential to avoid inadvertent vascular injury during surgery.
Microsurgical Treatment of Basilar Apex Aneurysms: Perioperative and Long-term Clinical Outcome
Authors: Lozier Alan P. , Kim Grace H. , Sciacca Robert R. , Connolly E. Sander , Solomon Robert A.
Published: August 2004

OBJECTIVE

We sought to analyze the perioperative and long-term clinical outcome data for patients with microsurgically treated basilar apex aneurysms.

METHODS

We identified 98 consecutively treated basilar apex aneurysms in patients prospectively enrolled in a cerebral aneurysm database.

RESULTS

Fifty patients presented with subarachnoid hemorrhage, and 19 aneurysms were giant. Eighty-four of 98 aneurysms were directly clipped. Surgical morbidity was 19.4% for the entire cohort and 8.8% for the unruptured, nongiant subgroup. The most common complication resulting in long-term morbidity was perforator injury. Sixty-seven percent of patients with clipped aneurysms were independent at discharge; this fraction increased to 79.0% at the 3-month follow-up examination. Good long-term outcomes (modified Rankin Scale score ≤2) were achieved in 56 (70%) of 80 cases. The mean Barthel Index of surviving patients was 95.8 ± 15.0 (median = 100, n = 66). Patients with unruptured, nongiant lesions fared considerably better than patients in other cohorts. Ninety-three percent of this subgroup was independent at discharge; this fraction increased to 100% at the 3-month follow-up examination (n = 27). In univariate analyses, poor clinical grade, giant aneurysm size, major operative complications, and operations performed early in the series were associated with worse outcomes. In the multivariate analysis, unruptured giant aneurysm status was found to confer a tremendous risk for poor outcome (risk ratio, 80.0; 95% confidence interval, 8.0–800.7; P < 0.01). Surviving patients were observed for a mean clinical follow-up period of 7.4 ± 3.7 years. The annual rate of postoperative subarachnoid hemorrhage was 0.18% for all clipped aneurysms and 0% for completely clipped lesions.

CONCLUSION

In comparison to data from the existing literature regarding Guglielmi detachable coil embolization of basilar apex aneurysms, the data presented suggest that surgical clipping should be an important component of a multimodality approach to the treatment of patients with basilar apex aneurysms.
Safety of High-dose Intravenous Eptifibatide as an Adjunct to Internal Carotid Artery Angioplasty and Stent Placement: A Prospective Registry
Authors: Qureshi Adnan I. , Siddiqui Amir M. , Hanel Ricardo A. , Xavier Andrew R. , Kim Stanley H. , Kirmani Jawad F. , Boulos Alan S. , Hopkins L. Nelson
Published: August 2004

OBJECTIVE

Eptifibatide, a competitive platelet glycoprotein IIb-IIIa receptor inhibitor with high selectivity for platelet glycoprotein IIb-IIIa receptors and a short half-life, has been shown to reduce the risk of ischemic events associated with coronary interventions, particularly when used in high doses. However, its role in conjunction with neurointerventional procedures needs to be determined. We report the results of an open-label prospective registry to evaluate the safety (in terms of avoiding hemorrhagic complications) and effectiveness (in terms of preventing ischemic complications such as stroke) of administering high-dose eptifibatide during internal carotid artery angioplasty and stent placement (CAS) for extracranial carotid artery stenosis.

METHODS

After femoral artery access was established and intravenous heparin (30 U/kg bolus) was administered, each patient was administered intravenous eptifibatide (two 180-μg/kg single-dose boluses before CAS, then a 2.0-μg/kg/min infusion for 20–24 hours thereafter). The primary end point was the 30-day composite occurrence of death, cerebral infarction, and unplanned or urgent endovascular or surgical intervention. The primary safety end point was bleeding, for which complications were classified according to the Thrombolysis in Myocardial Infarction scheme as major (hemoglobin decrease of more than 5 g/dl), minor (hemoglobin decrease of 3–5 g/dl), or insignificant. Platelet aggregation was measured in 13 consecutive patients with a rapid platelet-function analyzer.

RESULTS

Twenty-six patients (mean age, 68.1 ± 9.4 yr; 16 men) underwent treatment. The infusion and the CAS procedure were discontinued in one patient who developed angioneurotic edema after being administered intravenous heparin and the first bolus dose of eptifibatide. Among the 25 patients who underwent the procedure, no intracerebral hemorrhages and one minor ischemic stroke occurred during the 1-month follow-up period. The minor stroke was observed on postprocedure Day 7 in a patient for whom antiplatelet therapy was discontinued before a coronary artery bypass graft operation was performed. Another patient was discharged after an uncomplicated hospitalization but died as a result of urinary sepsis 12 days after CAS. One episode of major bleeding from the femoral insertion site required surgical repair and blood transfusions. Minor bleeding occurred in one patient. Platelet aggregation measurements obtained in 13 patients revealed a high degree (mean, 96%; range, 86–100%) of platelet inhibition after the administration of the second bolus dose of intravenous eptifibatide.

CONCLUSION

High-dose eptifibatide administered as an adjunct to CAS seems to be safe. Further studies are required to analyze its effectiveness and role in neurointerventional procedures.
Functional Anatomy of the Human Cochlear Nerve and Its Role in Microvascular Decompressions for Tinnitus
Authors: De Ridder Dirk , Ryu Hiroshi , Møller Aage R. , Nowé Vicky , Van de Heyning Paul , Verlooy Jan
Published: August 2004

OBJECTIVE

The functional anatomy (i.e., tonotopy) of the human cochlear nerve is unknown. A better understanding of the tonotopy of the central nervous system segment of the cochlear nerve and of the pathophysiology of tinnitus might help to ameliorate the disappointing results obtained with microvascular decompressions in patients with tinnitus.

METHODS

We assume that vascular compression of the cochlear nerve can induce a frequency-specific form of hearing loss and that when the nerve is successfully decompressed, this hearing loss can recuperate. Thirty-one patients underwent a microvascular decompression of the vestibulocochlear nerve for vertigo or tinnitus. Preoperative audiograms were subtracted from postoperative audiograms, regardless of the surgical result with regard to the tinnitus and vertigo, because the hearing improvement could be the only sign of the vascular compression. The frequency of maximal improvement was then correlated to the site of vascular compression. A tonotopy of the cochlear nerve was thus obtained.

RESULTS

A total of 18 correlations can be made between the site of compression and postoperative maximal hearing improvement frequency when 5-dB hearing improvement is used as threshold, 13 when 10-dB improvement is used as threshold. A clear distribution can be seen, with clustering of low frequencies at the posterior and inferior side of the cochlear nerve, close to the brainstem, and close to the root exit zone of the facial nerve. High frequencies are distributed closer to the internal acoustic meatus and more superiorly along the posterior aspect of the cochlear nerve.

CONCLUSION

The tonotopic organization of the cisternal segment of the cochlear nerve has an oblique rotatory structure as a result of the rotatory course of the cochlear nerve in the posterior fossa. Knowledge of this tonotopic organization of the auditory nerve in its cisternal course might benefit surgeons who perform microvascular decompression operations for the vestibulocochlear compression syndrome, especially in the treatment of unilateral severe tinnitus.
Gene Microarray Analysis of Human Brain Arteriovenous Malformations
Authors: Hashimoto Tomoki , Lawton Michael T. , Wen Gen , Yang Guo-Yuan , Chaly Thomas , Stewart Campbell L. , Dressman Holly K. , Barbaro Nicholas M. , Marchuk Douglas A. , Young William L.
Published: August 2004

OBJECTIVE

Human brain arteriovenous malformations (BAVMs) display abnormal expression of various angiogenesis-related genes and their products. We examined gene expression patterns in BAVMs by the gene microarray technique.

METHODS

We analyzed BAVM and control brain samples obtained by temporal lobectomy for medically intractable seizure by Affymetrix Human Gene Set U95Av2 (Affymetrix, Inc., Santa Clara, CA). The gene microarray data were compared with new and previously published data that used conventional molecular biology techniques.

RESULTS

We analyzed six BAVM and five control brain samples. From 12,625 gene probes assayed, 1781 gene probes showed differential expression between BAVMs and controls. BAVM samples had a gene expression pattern that was distinct from those of control brain samples. Increased messenger ribonucleic acid expression of vascular endothelial growth factor A was accompanied by increased expression of its protein product. A majority of the gene data was in agreement with previously published data. The gene microarray data generated a new testable hypothesis regarding integrin, and we found increased expression of integrin αvβ3 protein in BAVMs.

CONCLUSION

The gene expression pattern of BAVMs was distinct from those of control brain samples. We verified the gene microarray data by demonstrating that increased gene expression levels for angiogenesis-related molecules were accompanied by increased levels of their protein product expression. The gene microarray technique may be a useful tool to study multiple pathways simultaneously in BAVM specimens.
Correlation between Promoter Hypermethylation of the O6-Methylguanine-Deoxyribonucleic Acid Methyltransferase Gene and Prognosis in Patients with High-grade Astrocytic Tumors Treated with Surgery, Radiotherapy, and 1-(4-Amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based Chemotherapy
Authors: Kamiryo Takanori , Tada Kenji , Shiraishi Shoji , Shinojima Naoki , Kochi Masato , Ushio Yukitaka
Published: August 2004

OBJECTIVE

O 6-Methylguanine-deoxyribonucleic acid methyltransferase (MGMT) is a deoxyribonucleic acid repair protein associated with the chemoresistance of chloroethylnitrosoureas. We investigated whether MGMT promoter hypermethylation is associated with prognosis in patients with high-grade astrocytic tumors treated uniformly with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU)-based chemotherapy.

METHODS

Using the methylation-specific polymerase chain reaction, we assayed promoter hypermethylation of the MGMT gene in tumor deoxyribonucleic acid from 116 adult patients with supratentorial high-grade astrocytic tumors (42 anaplastic astrocytomas [AAs] and 74 glioblastomas multiforme [GBMs]). The Cox proportional hazards model was used in forward stepwise regression to assess the relative role of prognostic factors (i.e., age at surgery, sex, Karnofsky Performance Scale score, extent of surgical resection, methylation status of the MGMT promoter, and association between MGMT promoter methylation and survival).

RESULTS

MGMT promoter hypermethylation was confirmed in 19 (45.2%) of 42 AA patients and 33 (44.6%) of 74 GBM patients. It was significantly associated with both longer overall and progression-free survival time in AA but not GBM patients.

CONCLUSION

Our results demonstrate that MGMT promoter hypermethylation is associated with longer survival time in patients with AA who were treated with surgery, radiotherapy, and ACNU-based chemotherapy but not in patients with GBM.