bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebral protection by intermittent reperfusion during temporary focal ischemia in the rat
Authors: David Carlos A. , Prado Ricardo , Dietrich W. Dalton 
Published: June 2009

✓ Temporary arterial occlusion has been routinely used as an adjunct in intracranial aneurysm surgery. This has commonly been performed using a protocol of multiple short periods of occlusion alternating with periods of restoration of normal circulation. Recently, the logical basis of this method has come under scrutiny. There is extensive experimental evidence to suggest that repetitive, brief periods of global ischemia may cause more severe cerebral injury than an equivalent single period of global ischemia. Only recently has this issue begun to be addressed with regard to focal ischemia. Hence, despite the common use of temporary clipping, little experimental data are available regarding the ischemic consequences of temporary arterial occlusion with periods of reperfusion versus uninterrupted temporary occlusion.
To investigate this issue, a protocol of occlusion/reperfusion that simulates the temporal profile that occurs during surgery was performed in a rat model of focal ischemia. Sixteen anesthetized Sprague—Dawley rats were divided into two groups. The animals in Group I underwent 60 minutes of uninterrupted middle cerebral artery occlusion and the animals in Group II were subjected to six separate 10-minute occlusion periods with 5 minutes of reperfusion between occlusions. Histopathological analysis was performed 72 hours postischemia. Group I had significantly increased mean infarction volumes (50.0 ± 12.1 mm3) compared to Group II (8.7 ± 3.1 mm3) (p = 0.008). Injuries in Group I occurred in both the cortex and striatum, whereas Group II showed only striatal injuries. Furthermore, the extent of the injuries in Group II was less severe, characterized by ischemic neuronal injury rather than frank infarction.
The results indicate that intermittent reperfusion is neuroprotective during temporary focal ischemia and support the hypothesis that intermittent reperfusion is beneficial if temporary clipping is required during aneurysm repair.
Preliminary results of linear accelerator radiosurgery for acoustic schwannomas
Authors: Mendenhall William M. , Friedman William A. , Buatti John M. , Bova Francis J. 
Published: June 2009

✓ In this paper the authors evaluate the results of linear accelerator (LINAC)—based stereotactic radiosurgery for acoustic schwannomas.Fifty-six patients underwent LINAC-based stereotactic radiosurgery for acoustic schwannomas at the University of Florida between July 1988 and November 1994. Each patient was followed for a minimum of 1 year or until death; no patient was lost to follow up. One or more follow-up magnetic resonance images or computerized tomography scans were obtained in 52 of the 56 patients. Doses ranged between 10 and 22.5 Gy with 69.6% of patients receiving 12.5 to 15 Gy. Thirty-eight patients (68%) were treated with one isocenter and the dose was specified to the 80% isodose line in 71% of patients.Fifty-five patients (98%) achieved local control after treatment. The 5-year actuarial local control rate was 95%. At the time of analysis, 48 patients were alive and free of disease, seven had died of intercurrent disease, and one was alive with disease. Complications developed in 13 patients (23%). The likelihood of complications was related to the dose and treatment volume: 10 to 12.5 Gy to all volumes, three (13%) of 23 patients; 15 to 17.5 Gy to 5.5 cm3 or less, two (9%) of 23 patients; 15 to 17.5 Gy to more than 5.5 cm3, five (71%) of seven patients; and 20 to 22.5 Gy to all volumes, three (100%) of three patients.Linear accelerator—based stereotactic radiosurgery results in a high rate of local control at 5 years. The risk of complications is related to the dose and treatment volume.
Cerebral sparganosis: clinical manifestations, treatment, and outcome
Authors: Kim Dong Gyu , Paek Sun Ha , Chang Kee-Hyun , Wang Kyu-Chang , Jung Hee-Won , Kim Hyun Jib , Chi Je G. , Choi Kil Soo , Han Dae Hee 
Published: June 2009

✓ Cerebral sparganosis is a rare parasitic disease caused by infestation by the plerocercoid larva of Spirometra mansoni. The authors retrospectively analyzed 17 cases of cerebral sparganosis treated at Seoul National University Hospital between 1986 and 1994. The patients' ages at diagnosis ranged from ± to 57 years (median 32 years) and the male/female ratio was 13:4. Diagnosis was based on radiological findings, serological test results, operative findings, and histopathological examinations. Characteristic magnetic resonance (MR) findings consisted of widespread white matter degeneration and cortical atrophy, mixed-signal lesion (low in the central and high in the peripheral regions on T2-weighted images) with irregular dense enhancement of central foci and changes in the location and shape of the enhancing lesion in follow-up studies. Ten patients underwent surgical removal of the parasitic lesion, six received medical treatment alone (five with praziquantel and one with antiepileptic drugs), and one underwent insertion of a ventriculoperitoneal shunt and a course of praziquantel. Follow-up periods ranged from 13 to 111 months (mean 49 months). Seven patients who underwent complete removal of the lesion, live worm, or degenerative worm with surrounding granuloma showed a favorable course. Patients who received medical treatment alone or incomplete removal exhibited progression in their neurological deficits and their seizures could not be controlled. Medication with praziquantel seemed to have no killing effect on live worms.
The authors conclude that MR imaging is the most valuable modality for the early detection of cerebral sparganosis and that complete surgical removal of granuloma together with worms, whether they are alive or degenerative, is the treatment of choice.
Observer reliability in histological grading of astrocytoma stereotactic biopsies
Authors: Mittler Mark A. , Walters Beverly C. , Stopa Edward G. 
Published: June 2009

✓ This study provides an objective assessment of the reliability of histological grading of astrocytoma specimens obtained using stereotactic biopsy. Pathological diagnosis of brain tumors provides an index of disease severity and guides clinical practice in their treatment. It also functions as the gold standard in assessing the validity of diagnostic tests such as magnetic resonance imaging. Often diagnoses are made from biopsy material obtained using stereotactic technique. The current study was designed to evaluate this gold standard with regard to interobserver and intraobserver variability.
Four certified neuropathologists from academic centers in the United States and Canada were asked to grade 30 brain biopsy specimens obtained stereotactically in patients with astrocytomas. Intraobserver agreement was analyzed in individual observers by comparing their first and second readings, separated by 5 to 14 weeks. Interobserver data were analyzed by comparing initial readings across all observers for individual diagnoses. Kappa analysis was used to measure agreement beyond chance.
Intraobserver agreement was 74.73% for glioblastomas multiforme, 51.43% for anaplastic astrocytomas, and 65.22% for low-grade astrocytomas. The most common disagreements were between anaplastic astrocytomas and glioblastomas multiforme, followed by disagreements between anaplastic and low-grade astrocytomas. Interobserver agreement on initial readings was 62.41% (κ 0.39) for glioblastomas, 36.04% (κ 0.06) for anaplastic astrocytomas, and 57.14% (κ 0.48) for low-grade astrocytomas.
A significantly greater degree of reliability was seen in histopathological diagnoses of low- or high-grade astrocytomas than in those of intermediate-grade astrocytomas. Therefore, the highest variability occurs at the point of clinical decision making—namely, intermediate-grade tumors that may or may not be selected to receive adjuvant therapy. This considerable variability is an issue that needs to be recognized and further addressed by analysis of current and proposed astrocytoma grading schemes.
External hydrocephalus in adults
Authors: Cardoso érico R. , Schubert Romaine 
Published: June 2009

✓ The authors report three adult patients who developed a symptomatic extraaxial collection of cerebrospinal fluid (CSF) after an intracranial hemorrhage. The fluid shifted from the extraaxial into the ventricular space as the patients' symptoms progressed. The symptoms resolved after placement of a ventriculoperitoneal shunt.External hydrocephalus, which is frequently observed in children, had not yet been described in adults. It is important to differentiate chronic subdural collections from external hydrocephalus, because ventricular CSF shunting increases the former while it is the treatment for the latter. The authors believe that symptomatic extraaxial fluid collections developed in these three adults during the early phase of posthemorrhagic hydrocephalus because the ventricles presented great resistance to distention at the onset of hydrocephalus. Animal experiments have led to the same result.
Continuous intraoperative electromyographic monitoring of cranial nerves during resection of fourth ventricular tumors in children
Authors: Grabb Paul A. , Albright A. Leland , Sclabassi Robert J. , Pollack Ian F. 
Published: June 2009

✓ The authors reviewed the results of continuous intraoperative electromyographic (EMG) monitoring of muscles innervated by cranial nerves in 17 children whose preoperative imaging studies showed compression or infiltration of the fourth ventricular floor by tumor to determine how intraoperative EMG activity correlated with postoperative cranial nerve morbidity. Bilateral lateral rectus (sixth) and facial (seventh) nerve musculatures were monitored in all children. Cranial nerve function was documented immediately postoperatively and at 1 year.
Of the 68 nerves monitored, nine new neuropathies occurred in six children (sixth nerve in four children and seventh nerve in five). In five new neuropathies, intraoperative EMG activity could be correlated in one of four sixth nerve injuries and four of five seventh nerve injuries. Electromyographic activity could not be correlated in four children with new neuropathies. Of 59 cranial nerves monitored that remained unchanged, 47 had no EMG activity. Twelve cranial nerves (three sixth nerves and nine seventh nerves) had EMG activity but no deficit. Of four children with lateral rectus EMG activity, three had new seventh nerve injuries.
Lateral rectus EMG activity did not predict postoperative abducens injury. The absence of lateral rectus EMG activity did not assure preserved abducens function postoperatively. Likely because of the close apposition of the intrapontine facial nerve to the abducens nucleus, lateral rectus EMG activity was highly predictive of seventh nerve injury. Although facial muscle EMG activity was not an absolute predictor of postoperative facial nerve dysfunction, the presence of facial muscle EMG activity was associated statistically with postoperative facial paresis. The absence of facial muscle EMG activity was rarely associated with facial nerve injury. The authors speculate that EMG activity in the facial muscles may have provided important intraoperative information to the surgeon so as to avoid facial nerve injury.
Outcome analysis for adults with spondylolisthesis treated with posterolateral fusion and transpedicular screw fixation
Authors: Schnee Charles L. , Freese Andrew , Ansell Lee V. 
Published: June 2009

✓ The outcomes of 52 adult patients with symptomatic low-grade spondylolisthesis treated with autologous posterolateral arthrodesis and pedicle screw fixation were retrospectively reviewed.Although a 90% rate of successful fusion was obtained using this technique, only 60% of patients were considered to have good outcomes. Treatment failures consisted mostly of back pain and were not predicted by preoperative symptoms. Compensation claims and smoking had very significant adverse impacts on both employment and pain results despite high fusion rates, particularly in patients under the age of 55 years. Overall, patients who required more than one operation demonstrated poor outcomes compared to those who only needed one. However, patients with at least two prior operations or preoperative pseudoarthrosis fared particularly poorly, whereas those who had undergone only one prior surgery and had no attendant compensation issue reported good results. A trend toward poor outcome was observed in patients with postlaminectomy spondylolisthesis, versus those with isthmic or degenerative etiologies. Gender did not exert an impact on outcome.The authors conclude that autologous posterolateral arthrodesis combined with pedicle screw fixation resulted in a high fusion rate, and contributed to successful outcomes in the treatment of certain subgroups of adults with spondylolisthesis. In the absence of other risk factors, patients may obtain significant benefit from surgery despite older age and a single failed operation. Careful patient selection appears critical in predicting the maximum benefit from this technique.
Reducing the risk of rebleeding before early aneurysm surgery: a possible role for antifibrinolytic therapy
Authors: Leipzig Thomas J. , Redelman Kathleen , Horner Terry G. 
Published: June 2009

✓ Previous studies on the initial nonoperative management of aneurysmal subarachnoid hemorrhage (SAH) demonstrated that antifibrinolytic therapy reduced the risk of rebleeding by approximately 50%; however, prolonged antifibrinolytic treatment was associated with an increase in the incidence of hydrocephalus and delayed ischemic deficit. When early surgical intervention became routine for ruptured aneurysms, the use of antifibrinolytic therapy diminished. However, early surgery is generally performed in the first several days after SAH and the risk of rebleeding remains until the aneurysm is obliterated. Based on a review of the literature, the authors formed two hypotheses: 1) the high-dose intravenous administration of epsilon-aminocaproic acid (EACA), an antifibrinolytic agent, might reduce the risk of recurrent hemorrhage in the interval between SAH and early surgical intervention, and 2) a short course of EACA might not produce the increase in complications previously associated with its prolonged administration.
The use of preoperative high-dose EACA therapy was evaluated in 307 patients to determine its safety and efficacy in reducing the incidence of rebleeding before early aneurysm surgery. All patients were admitted within 3 days of their SAH and were classified as Hunt and Hess Grades I to III. Only four patients (1.3%) suffered a recurrent hemorrhage. This compares favorably to the rebleeding rate of 5.7% reported for the early surgery group in the International Cooperative Study on the Timing of Aneurysm Surgery.
The incidence of hydrocephalus or symptomatic vasospasm was not unduly elevated in patients receiving preoperative EACA. Thirty-five patients (11.4%) needed temporary cerebrospinal fluid drainage during their hospitalization and, overall, 8.8% required a ventriculoperitoneal shunt. The mean age of the patients who required a shunt was nearly 10 years older than the general study population. Seventy-one patients (23%) developed symptomatic vasospasm and 8.1% suffered a stroke.
This study indicates that a brief course of high-dose EACA is safe and may be beneficial in diminishing the risk of rebleeding in good-grade patients prior to early surgical intervention. Further investigation is planned based on these promising results.
Development of anterior cranial fossa dural arteriovenous malformation following head trauma
Authors: Ishikawa Tatsuya , Houkin Kiyohiro , Tokuda Kouichi , Kawaguchi Susumu , Kashiwaba Takeshi 
Published: June 2009

✓ Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital.
The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier.
This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.
Guglielmi detachable coil embolization of acute intracranial aneurysm: perioperative anatomical and clinical outcome in 403 patients
Authors: Viñuela Fernando , Duckwiler Gary , Mawad Michel 
Published: June 2009

✓ From December 1990 to July 1995, the investigators participated in a prospective clinical study to evaluate the safety of the Guglielmi detachable coil (GDC) system for the treatment of aneurysms. This report summarizes the perioperative results from eight initial interventional neuroradiology centers in the United States. The report focuses on 403 patients who presented with acute subarachnoid hemorrhage from a ruptured intracranial aneurysm. These patients were treated within 15 days of the primary intracranial hemorrhage and were followed until they were discharged from the hospital or died.
Seventy percent of the patients were female and 30% were male. The patients' mean age was 58 years old. Aneurysm size was categorized as small (60.8%), large (34.7%), and giant (4.5%); and neck size was categorized as small (53.6%), wide (36.2%), fusiform (6%), and undetermined (4.2%). Fifty-seven percent of the aneurysms were located in the posterior circulation and 43% in the anterior circulation.
Eighty-two patients were classified as Hunt and Hess Grade I (20.3%), 105 Grade II (26.1%), 121 Grade III (30%), 69 Grade IV (17.1%), and 26 Grade V (6.5%). All patients in this study were excluded from surgical treatment either because of anticipated surgical difficulty (69.2%), attempted and failed surgery (12.7%), the patient's poor neurological (12.2%) or medical (4.7%) status, and/or refusal of surgery (1.2%).
The GDC embolization was performed within 48 hours of primary hemorrhage in 147 patients (36.5%), within 3 to 6 days in 156 patients (38.7%), 7 to 10 days in 71 patients (17.6%), and 11 to 15 days in 29 patients (7.2%). Complete aneurysm occlusion was observed in 70.8% of small aneurysms with a small neck, 35% of large aneurysms, and 50% of giant aneurysms. A small neck remnant was observed in 21.4% of small aneurysms with a small neck, 57.1% of large aneurysms, and 50% of giant aneurysms. Technical complications included aneurysm perforation (2.7%), unintentional parent artery occlusion (3%), and untoward cerebral embolization (2.48%). There was a 8.9% immediate morbidity rate related to the GDC technique. Seven deaths were related to technical complications (1.74%) and 18 (4.47%) to the severity of the primary hemorrhage.
The findings of this study demonstrate the safety of the GDC system for the treatment of ruptured intracranial aneurysms in anterior and posterior circulations. The authors believe additional randomized studies will further identify the role of this technique in the management of acutely ruptured incranial aneurysms.
Results of surgery for head and neck tumors that involve the carotid artery at the skull base
Authors: Brisman Michael H. , Sen Chandranath , Catalano Peter 
Published: June 2009

✓ To evaluate the results of surgery in patients with head and neck cancers that involved the internal carotid artery at the skull base the authors retrospectively reviewed a consecutive series of 17 patients who underwent surgery at Mount Sinai Hospital over a 4-year period. In general, patients who underwent tumor resection with carotid preservation had less advanced disease (two of seven tumors were recurrences) than patients who underwent tumor resection with carotid sacrifice (seven of 10 tumors were recurrences).
Of seven patients who underwent resection with carotid preservation, six had good outcomes (five patients alive in good condition, one dead at 2.2 years) and none had strokes. Of seven patients who underwent resection with carotid sacrifice and bypass, five had good outcomes (four alive in good condition, one dead at 2.5 years with no local recurrence) and two suffered graft occlusions that led to strokes, one of which was major and permanently disabling. Of three patients who underwent resection with carotid sacrifice and ligation without revascularization, there were no good outcomes: all three patients died within 6 months of surgery, two having suffered major permanently disabling strokes. The overall results (11 [65%] of 17 with good outcomes at an average follow-up period of 2.1 years) compared very favorably with historical nonsurgical controls.
The authors conclude that tumor resection with carotid perservation carries the lowest risk of stroke and should usually be the treatment of choice. For patients with more advanced and recurrent disease, in whom it is believed that carotid preservation would prevent a safe and oncologically meaningful resection, carotid sacrifice with carotid bypass may be a useful treatment option. Carotid sacrifice without revascularization seems to be the treatment option with the least favorable results.
Selective excision of adenomas originating in or extending into the pituitary stalk with preservation of pituitary function
Authors: Mason R. Bryan , Nieman Lynnette K. , Doppman John L. , Oldfield Edward H. 
Published: June 2009

✓ When the surgeon identifies an adenoma within the gland and selectively excises it, endocrine-active pituitary tumors are usually cured and pituitary function is preserved. Occasionally ectopic adenomas arise primarily in the pituitary stalk or arise superiorly in the midportion of the anterior lobe and extend upward within the stalk. To determine if these tumors can be selectively excised with preservation of pituitary function, the authors examined the outcome of selective adenomectomy in 10 patients with Cushing's disease with an ectopic adenoma originating in, and confined to, the stalk (four microadenomas) or an adenoma extending superiorly through the diaphragma sella and into the stalk (five microadenomas and one macroadenoma) from an operative series of 516 patients with Cushing's disease.
To reach the adenoma transsphenoidally in these patients, the diaphragma sella was incised anteroposteriorly in the midline to the anterior edge of the stalk, the suprasellar cistern was entered, and the adenoma was selectively excised using care to limit injury to the infundibulum. After selective adenomectomy, Cushing's disease remitted in all patients. All patients were hypocortisolemic immediately after surgery and required hydrocortisone for up to 21 months. Apart from the adrenal axis, pituitary function was normal in five patients in the immediate postoperative period, including two patients with tumors confined to the stalk and three patients with preoperative hypothyroidism (one patient) and/or hypogonadism (three patients). Three others with transient postoperative hypothyroidism (one patient) or diabetes insipidus (two patients) had normal pituitary function within 7 months of surgery. One patient with hypothyroidism and one with hypogonadism before surgery had panhypopituitarism postoperatively. A patient with a microadenoma located high in the stalk next to the optic chiasm had bitemporal hemianopsia postoperatively.
These results demonstrate the feasibility of achieving curative transsphenoidal resection and preservation of pituitary function in cases of pituitary adenomas that are confined to the pituitary stalk or tumors that extend superiorly within the stalk from an intrasellar origin.