bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation between copper/zinc superoxide dismutase and the proliferation of neural stem cells in aging and following focal cerebral ischemia
Authors: Takemura Sunao , Kayama Takamasa , Kuge Atsushi , Ali Hasmat , Kokubo Yasuaki , Sato Shinya , Kamii Hideyuki , Goto Kaoru , Yoshimoto Takashi
Published: January 2008

Object

Neural stem cells (NSCs) have been demonstrated in the subventricular zone (SVZ) of the lateral ventricle and the subgranular zone of the hippocampal dentate gyrus (DG). Although aging rats manifest a decrease in NSCs, rats exposed to stress (for example, ischemia, epilepsy, radiation, and trauma) show an increase in these cells. In transgenic mice, the overexpression of human copper/zinc superoxide dismutase (SOD1), an endogenous antioxidant, has been reported to be a protective enzyme against transient focal cerebral ischemia. The authors investigated the correlation between SOD1 and the proliferation of NSCs in aging as chronic oxidative stress (Experiment 1) and acute oxidative stress induced by transient focal cerebral ischemia (Experiment 2) in mice.

Methods

Bromodeoxyuridine (BrdU) was used in the evaluation of NSCs. In Experiment 1, NSCs in the SVZ significantly increased in 16-month-old transgenic mice compared with wild-type mice (p = 0.0001). In Experiment 2, mice were subjected to 30-minute occlusions of the middle cerebral artery. The increase in NSCs in the DG in transgenic mice was significantly greater than that in wild-type mice (p < 0.05).

Conclusions

Results in this study suggest that chronic and acute oxidative stress may inhibit the proliferation of NSCs and that SOD1 may play a key role in NSC proliferation.
Category-specific cortical mapping: color-naming areas
Authors: Roux Franck-Emmanuel , Lubrano Vincent , Lauwers-Cances Valérie , Mascott Christopher R. , Démonet Jean-François
Published: January 2008

Object

It has been hypothesized that a certain degree of specialization exists within language areas, depending on some specific lexical repertories or categories. To spare hypothetical category-specific cortical areas and to gain a better understanding of their organization, the authors studied patients who had undergone electrical stimulation mapping for brain tumors and they compared an object-naming task with a category-specific task (color naming).

Methods

Thirty-six patients with no significant preoperative language deficit were prospectively studied during a 2-year period. Along with a reading task, both object- and color-naming tasks were used in brain mapping. During color naming, patients were asked to identify 11 visually presented basic colors. The modality specificity of the colornaming sites found was subsequently tested by asking patients to retrieve the color attributes of objects.

High individual variability was observed in language organization among patients and in the tasks performed. Significant interferences in color naming were found in traditional language regions—that is, Broca (p < 0.003) and Wernicke centers (p = 0.05)—although some color-naming areas were occasionally situated outside of these regions. Color-naming interferences were exclusively localized in small cortical areas (< 1 cm2). Anatomical segregation of the different naming categories was apparent in 10 patients; in all, 13 color-specific naming areas (that is, sites evoking no object-naming interference) were detected in the dominant-hemisphere F3 and the supramarginal, angular, and posterior parts of the temporal gyri. Nevertheless, no specific brain region was found to be consistently involved in color naming (p > 0.05). At five sites, although visually presented color-naming tasks were impaired by stimulation, auditory color naming (for example, “What color is grass?”) was performed with no difficulty, showing that modality-specific areas can be found during naming.

Conclusions

Within language areas, a relative specialization of cortical language areas for color naming can be found during electrical stimulation mapping.
Cerebral hemodynamic changes gauged by transcranial Doppler ultrasonography in patients with posttraumatic brain swelling treated by surgical decompression
Authors: Bor-Seng-Shu Edson , Hirsch Roberto , Teixeira Manoel Jacobsen , de Andrade Almir Ferreira , Marino Raul
Published: January 2008

Object

The use of decompressive craniectomy has experienced a revival in the previous decade, although its actual benefit on patients’ neurological outcome remains the subject of debate. A better understanding of the intracranial pressure dynamics, as well as of the metabolic and hemodynamic brain processes, may be useful in assessing the effect of this surgery on the pathophysiology of the swollen brain. The aim of this study was to use transcranial Doppler (TCD) ultrasonography to examine the hemodynamic changes in the brain after decompressive craniectomy in patients with head injury, in addition to examining the relationship between such hemodynamic changes and the patient’s neurological outcome.

Methods

Nineteen patients presenting with traumatic brain swelling and cerebral herniation syndrome who had undergone decompressive craniectomy with dural expansion were studied prospectively. The TCD ultrasonography measurements were performed bilaterally in both the middle cerebral artery (MCA) and in the distal portion of the cervical internal carotid artery (ICA) immediately prior to and after surgical decompression.

After surgery, the mean blood flow velocity (BFV) rose to 175 ± 209% of preoperative values in the MCA of the operated side, while rising to 132 ± 183% in the contralateral side; the difference between the mean BFV increase in in the MCA of both the decompressed and the opposite side reached statistical significance (p < 0.05). The mean BFV of the extracranial ICA increased to 91 ± 119% in the surgical side and 45 ± 60% in the opposite side. Conversely, the MCA pulsatility index (PI) values decreased, on average, to 33 ± 36% of the preoperative value in the operated side and to 30 ± 34% on the opposite side; the MCA PI value reductions were significantly greater in the decompressed side when compared with the contralateral side (p < 0.05). The PI of the extracranial ICA reduced, on average, to 37 ± 23% of the initial values in the operated side and to 24 ± 34%, contralaterally. No correlation was verified between the neurological outcome and cerebral hemodynamic changes seen on TCD ultrasonography.

Conclusions

Decompressive craniectomy results in a significant elevation of cerebral BFV in most patients with traumatic brain swelling and transtentorial herniation syndrome. The increase in cerebral BFV may also occur in the side opposite the decompressed hemisphere; the cerebral BFV increase is significantly greater in the operated hemisphere than contralaterally. Concomitantly, PI values decrease significantly postoperatively, mainly in the decompressed cerebral hemisphere, indicating reduction in cerebrovascular resistance.
Use of a self-expanding stent with balloon angioplasty in the treatment of dural arteriovenous fistulas involving the transverse and/or sigmoid sinus: functional and neuroimaging-based outcome in 10 patients
Authors: Levrier Olivier , Métellus Philippe , Fuentes Stephane , Manera Luis , Dufour Henry , Donnet Anne , Grisoli François , Bartoli Jean-Michel , Girard Nadine
Published: January 2008

Object

The goal of this study was to evaluate the clinical and angiography results in 10 patients with transverse–sigmoid dural arteriovenous fistulas (DAVFs) treated using sinus angioplasty and dural sinus stent insertion.

Methods

Between 2001 and 2003, 10 consecutive patients (six men and four women, age range 54–79 years) who had presented with transverse and/or sigmoid sinus DAVFs with or without sinus thrombosis underwent self-expanding stent placement and balloon angioplasty. Eight fistulas involved the transverse sinus, three the sigmoid sinus, and one the torcular and occipital sinuses. According to the Djindjian-Merland grading system, there were two Type I, five Type IIa, one Type IIb, and two Type IV DAVFs. The mean clinical follow-up period was 21.1 months. At the last follow-up examination, seven patients were asymptomatic and three were dramatically improved. The mean angiography follow-up period was 7.5 months for the available population: four patients had complete DAVF occlusion, four had significant flow reduction, and two who experienced clinical improvement refused conventional angiography control studies. Delayed computerized tomography angiography scans were obtained to evaluate stent permeability in nine of the 10 patients. Stent permeability was demonstrated in eight of the nine patients with available control studies at a mean follow up of 20.8 months. There were two transient neurological deficits but no severe and permanent complications.

Conclusions

In this series, sinus stent insertion resulted in a cure or significant clinical improvement in all patients harboring a DAVF, with no severe or permanent complication. Stent placement for transverse and/or sigmoid sinus DAVFs is a promising technique whose viability should be confirmed in larger series with longer follow-up periods.
Intrinsically radiopaque iodine-containing polyvinyl alcohol as a liquid embolic agent: evaluation in experimental wide-necked aneurysms
Authors: Dudeck Oliver , Jordan Olivier , Hoffmann Karl-Titus , Tesmer Kai , Kreuzer-Nagy Tibor , Podrabsky Petr , Heise Michael , Meyer Rudolf , Okuducu Ali Fuat , Bruhn Harald , Hilborn Jöns , Rüfenacht Daniel A. , Doelker Eric , Felix Roland
Published: January 2008

Object

To evaluate iodine-containing polyvinyl alcohol (I-PVA) as a precipitating liquid embolic agent, implant characteristics—including radiopacity, setting behavior, and biocompatibility—were studied in an aneurysm model in swine.

Methods

Twelve broad-based carotid artery (CA) sidewall aneurysms were surgically constructed in six pigs. Iodine-containing polyvinyl alcohol dissolved in dimethyl sulfoxide (DMSO) was injected during temporary balloon occlusion bridging the aneurysm neck. Control angiography as well as multidetector row computerized tomography (CT) angiography was performed after 4 weeks. Harvested aneurysms were investigated histopathologically and by 3-tesla high-field magnetic resonance (MR) imaging. The mean degree of aneurysm occlusion achieved was 96%. In two aneurysms a minimal protrusion of I-PVA into the CA lumen was observed. During one embolization, leakage of the liquid embolic agent due to DMSO-induced damage of the microcatheter resulted in CA occlusion. Aneurysms embolized with I-PVA could be discriminated clearly from the parent artery on CT angiograms because there was no beam-hardening artifact. High-field MR imaging allowed a detailed depiction of the liquid embolic distribution within the aneurysm. Histologically, a mild to moderate inflammatory response was found in successfully embolized aneurysms, and the polymer mass was frequently covered by a membrane of fibroblasts and endothelial cells.

Conclusions

Iodine-containing polyvinyl alcohol is a ready-to-use liquid embolic agent clearly visible under fluoroscopy; additives are not required. The setting behavior allows for controlled delivery in aneurysm cavities. Histological studies performed 4 weeks after embolization revealed no sign of toxic tissue response to the liquid embolic agent. Overall, I-PVA exhibits interesting implant characteristics in that radiopaque admixtures are not necessary, thus allowing for artifact-free evaluation of treated aneurysms by using CT and MR angiography.
The effect of 17β-estradiol in attenuating experimental subarachnoid hemorrhage–induced cerebral vasospasm
Authors: Lin Chih-Lung , Shih Huei-Chuan , Dumont Aaron S. , Kassell Neal F. , Lieu Ann-Shung , Su Yu-Feng , Hwong Shen-Long , Hsu Chin
Published: January 2008

Object

Sex differences in the outcome of aneurysmal subarachnoid hemorrhage (SAH) are controversial, and the potential influence of estradiol on vasodilation is unclear. In the present study the authors evaluate the effect and possible mechanism of 17β-estradiol (E2) on SAH-induced vasospasm in a two-hemorrhage rodent model of SAH.

Methods

A 30-mm Silastic tube filled with E2 in corn oil (0.3 mg/ml) was subcutaneously implanted in male rats. Serum levels of E2 were measured on Days 0, 1, 2, 3, 4, and 7 postimplantation. The degree of vasospasm was determined by averaging the cross-sectional areas of the basilar artery (BA) 7 days after the first SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) in the BA were also evaluated.

Serum levels of E2 in the E2-treated rats were at physiological levels (56–92 pg/ml) and were significantly higher than those in the control and vehicle-treated groups. Treatment with E2 significantly (p < 0.01) attenuated SAH-induced vasospasm. Induction of iNOS messenger (m)RNA and protein in the BA by SAH was significantly diminished by the E2 treatment but not by vehicle treatment. The SAH-induced suppression of eNOS mRNA and protein was relieved by E2 treatment.

Conclusions

These results suggest that continuous treatment with E2 at physiological levels prevents cerebral vasospasm following SAH. The beneficial effect of E2 may be in part related to the prevention of augmentation of iNOS expression and the preservation of normal eNOS expression after SAH. Treatment with E2 holds therapeutic promise in the treatment of cerebral vasospasm following SAH and merits further investigation.
Cavernous angioma within an olfactory groove meningioma
Authors: Klein Olivier , Freppel Sébastien , Auque Jean , Civit Thierry
Published: January 2008

✓The authors present the case of a 60-year-old woman who was admitted to their institution after suffering a subarachnoid hemorrhage (SAH). Neuroimaging data demonstrated an olfactory groove meningioma surrounded by a slight edema, but there was no evidence of SAH, although results of the lumbar puncture demonstrated xanthochromic cerebrospinal fluid. Angiography confirmed the diagnosis of meningioma, but results of magnetic resonance imaging led the authors to suspect a cavernoma within the meningioma. This diagnosis was established by pathological examination of the resected lesion. The patient did well and was discharged soon after surgery. This very rare association and the propensity of each of these lesions to be revealed by hemorrhage are discussed.
Iatrogenic cerebellar implantation of a vestibular schwannoma
Authors: Patrick Todd A. , Giannini Caterina , Ebersold Michael J. , Link Michael J.
Published: January 2008

✓ Metastatic seeding or iatrogenic implantation of numerous types of primary central nervous system tumors, typically along cerebrospinal fluid pathways, is a frequently described albeit rare phenomenon and has never been reported in association with vestibular schwannoma (VS). The authors present a case of inadvertent surgical implantation of VS into the cerebellar hemisphere during resection of a recurrent VS in the cerebellopontine angle and internal auditory canal. A 42-year-old man presented with a 2.5-cm right VS that was removed without complication via a retrosigmoid approach. Routine imaging performed 5 years later revealed a 1.5-cm recurrence of the VS that was subsequently removed by reopening the retrosigmoid craniotomy. Five years later—10 years after initial presentation—follow-up imaging revealed a 1-cm recurrence of the VS and a separate 2.2-cm tumor in the inferior cerebellar parenchyma with surrounding edema. Both tumors were removed without complication by reopening the previous retrosigmoid craniotomy. Histological evaluation of these tumors revealed features typical of VS and similar to those of the tissue obtained from the two prior resections. Given the similarities among these tumors in pathological appearance and mitotic index, the presence of the intraparenchymal cerebellar schwannoma was probably due to intraoperative iatrogenic implantation.
Outcome following decompressive craniectomy for malignant swelling due to severe head injury
Authors: Aarabi Bizhan , Hesdorffer Dale C. , Ahn Edward S. , Aresco Carla , Scalea Thomas M. , Eisenberg Howard M.
Published: January 2008

Object

The aim of this study was to assess outcome following decompressive craniectomy for malignant brain swelling due to closed traumatic brain injury (TBI).

Methods

During a 48-month period (March 2000–March 2004), 50 of 967 consecutive patients with closed TBI experienced diffuse brain swelling and underwent decompressive craniectomy, without removal of clots or contusion, to control intracranial pressure (ICP) or to reverse dangerous brain shifts. Diffuse injury was demonstrated in 44 patients, an evacuated mass lesion in four in whom decompressive craniectomy had been performed as a separate procedure, and a nonevacuated mass lesion in two. Decompressive craniectomy was performed urgently in 10 patients before ICP monitoring; in 40 patients the procedure was performed after ICP had become unresponsive to conventional medical management as outlined in the American Association of Neurological Surgeons guidelines. Survivors were followed up for at least 3 months posttreatment to determine their Glasgow Outcome Scale (GOS) score.

Decompressive craniectomy lowered ICP to less than 20 mm Hg in 85% of patients. In the 40 patients who had undergone ICP monitoring before decompression, ICP decreased from a mean of 23.9 to 14.4 mm Hg (p < 0.001). Fourteen of 50 patients died, and 16 either remained in a vegetative state (seven patients) or were severely disabled (nine patients). Twenty patients had a good outcome (GOS Score 4–5). Among 30-day survivors, good outcome occurred in 17, 67, and 67% of patients with postresuscitation Glasgow Coma Scale scores of 3 to 5, 6 to 8, and 9 to 15, respectively (p < 0.05). Outcome was unaffected by abnormal pupillary response to light, timing of decompressive craniectomy, brain shift as demonstrated on computerized tomography scanning, and patient age, possibly because of the small number of patients in each of the subsets. Complications included hydrocephalus (five patients), hemorrhagic swelling ipsilateral to the craniectomy site (eight patients), and subdural hygroma (25 patients).

Conclusions

Decompressive craniectomy was associated with a better-than-expected functional outcome in patients with medically uncontrollable ICP and/or brain herniation, compared with outcomes in other control cohorts reported on in the literature.
Surgical treatment and outcomes in 45 cases of posterior interosseous nerve entrapments and injuries
Authors: Kim Daniel H. , Murovic Judith A. , Kim Yong-Yeon , Kline David G.
Published: January 2008

Object

The authors report data in 45 surgically treated posterior interosseous nerve (PIN) entrapments or injuries.

Methods

Forty-five PIN entrapments or injuries were managed surgically between 1967 and 2004 at Louisiana State University Health Sciences Center (LSUHSC) or Stanford University Medical Center. Patient charts were reviewed retrospectively. The LSUHSC grading system was used to assess PIN-innervated muscle function.

Injuries were caused by nontraumatic (21 PIN entrapments and four tumors) and traumatic (nine lacerations, eight fractures, and three contusions) mechanisms. Presentations included weakness in the extensor carpi ulnaris muscle, causing compromised wrist extension and radial drift; extensor digitorum, indicis, and digiti minimi muscles with paretic finger extension; extensor pollicis brevis and longus muscles with weak thumb extension; and abductor pollicis longus muscle with rare decreased thumb abduction due to substitutions of the median nerve–innervated abductor pollicis brevis muscle and, at 90°, the extensor pollicis brevis and longus muscles. Preoperative evaluations consisted of electromyography and nerve conduction studies, elbow and forearm plain x-ray films, and magnetic resonance imaging for tumor detection.

At surgery, in continuity lesions were found in 21 entrapments and three fracture-related and three contusion injuries; all transmitted nerve action potentials (NAPs) and were treated with neurolysis. Five fracture-related PIN injuries, one of which was a lacerating injury, were in continuity and transmitted no NAPs; graft repairs were performed in all of these cases. Among nine lacerations, three PINs appeared in continuity, although intraoperative NAPs were absent. Two of these nerves were treated with secondary end-to-end suture anastomosis repair and one with secondary graft repair. There were six transected lacerations: three were treated with primary suture anastomosis repair, two with secondary suture anastomosis, and one with graft repair. Four tumors involving the PIN were resected. Most muscles innervated by 45 PINs had LSUHSC Grade 3 or better functional outcomes.

Conclusions

Forty-five PIN entrapments or injuries responded well to PIN release and/or repair.
Quantitation of and superficial surgical landmarks for the anterior interosseous nerve
Authors: Tubbs R. Shane , Custis James W. , Salter E. George , Wellons John C. , Blount Jeffrey P. , Oakes W. Jerry
Published: January 2008

Object

There are scant data regarding the anterior interosseous nerve (AIN) in the neurosurgical literature. In the current study the authors attempt to provide easily identifiable superficial osseous landmarks for the identification of the AIN.

Methods

The AIN in 20 upper extremities obtained in adult cadaveric specimens was dissected and quantified. Measurements were obtained between the nerve and surrounding superficial osseous landmarks.

The AIN originated from the median nerve at mean distances of 5.4 cm distal to the medial epicondyle of the humerus and 21 cm proximal to the ulnar styloid process. The distance from the origin of the AIN to its branch leading to the flexor pollicis longus muscle and to the point it travels deep to the pronator quadratus (PQ) muscle measured a mean 4 and 14.4 cm, respectively. The mean distance from the AIN branch leading to the flexor pollicis longus muscle to the proximal PQ muscle was 12.1 cm, and the mean distance between this branch and the ulnar styloid process was 7.2 cm. The mean diameter of the AIN was 1.6 mm at the midforearm.

Conclusions

Additional landmarks for identification of the AIN can aid the neurosurgeon in more precisely isolating this nerve and avoiding complications. Furthermore, after quantitation of this nerve, the AIN branches can be easily used for neurotization of the median and ulnar nerves, and with the aid of a transinterosseous membrane tunneling technique, passed to the posterior interosseous nerve.
Use of an intact sensory nerve to bridge a motor nerve defect: an experimental study
Authors: Tirelioğlu Serçin , Özbek Serhat , Özcan Mesut , Kurt M. Ayberk , Noyan Bezhat
Published: January 2008

Object

End-to-side neurorrhaphy has recently became popular for peripheral nerve repair. Although this method is mainly indicated in nerve defects in which there is an absent proximal nerve stump, bridging a motor nerve defect by coapting the proximal and distal ends of the defect to a neighboring mixed nerve in an end-to-side fashion has been another experimental use of this method. In this situation, however, the source of the regenerating axons is unclear because the axons in both the proximal end of the defect and the bridging intact nerve have the capacity for regeneration. The goal of this study was to identify the source of the regenerating axons.

Methods

In this experimental study, the authors used a sensory nerve to bridge a motor nerve defect so that they could elucidate the source of the regenerating motor axons in the distal part of the motor nerve. One advantage of using a sensory nerve was that it eradicated the risk of damaging another motor nerve. Tests used in the analysis included gait evaluation, electrophysiological tests, and histological assessment.

Conclusions

Results of this study showed that, in the rat model, a sensory nerve can be used to bridge a motor nerve defect, thereby eliminating the need for nerve grafting.
Amplitude and phase of cerebrospinal fluid pulsations: experimental studies and review of the literature
Authors: Wagshul Mark E. , Chen John J. , Egnor Michael R. , McCormack Erin J. , Roche Patricia E.
Published: January 2008

Object

A recently developed model of communicating hydrocephalus suggests that ventricular dilation may be related to the redistribution of pulsations in the cranium from the subarachnoid spaces (SASs) into the ventricles. Based on this model, the authors have developed a method for analyzing flow pulsatility in the brain by using the ratio of aqueductal to cervical subarachnoid stroke volume and the phase of cerebrospinal fluid (CSF) flow, which is obtained at multiple locations throughout the cranium, relative to the phase of arterial flow.

Methods

Flow data were collected in a group of 15 healthy volunteers by using a series of images acquired with cardiac-gated, phase-contrast magnetic resonance imaging.

The stroke volume ratio was 5.1 ± 1.8% (mean ± standard deviation). The phase lag in the aqueduct was −52.5 ± 16.5° and the phase lag in the prepontine cistern was −22.1 ± 8.2°. The flow phase at the level of C-2 was +5.1 ± 10.5°, which was consistent with flow synchronous with the arterial pulse. The subarachnoid phase lag ventral to the pons was shown to decrease progressively to zero at the craniocervical junction. Flow in the posterior cervical SAS preceded the anterior space flow.

Conclusions

Under normal conditions, pulsatile ventricular CSF flow is a small fraction of the net pulsatile CSF flow in the cranium. A thorough review of the literature supports the view that modified intracranial compliance can lead to redistribution of pulsations and increased intraventricular pulsations. The phase of CSF flow may also reflect the local and global compliance of the brain.
Regression of intracranial Rosai–Dorfman disease following corticosteroid therapy
Authors: McPherson Christopher M. , Brown Justin , Kim Angela W. , Demonte Franco
Published: January 2008

✓ Rosai–Dorfman disease (RDD) is an idiopathic histioproliferative disorder usually presenting with massive, painless lymphadenopathy. Extranodal involvement has been reported including at least 50 cases affecting the central nervous system (CNS). The treatment of CNS RDD as reported in the literature has primarily involved a surgical technique. The authors report on the case of a 53-year-old man presenting with multiple skull base lesions mimicking meningiomas. The patient suffered visual deterioration and underwent a right orbitopterional craniotomy as well as optic nerve decompression. Histopathological analysis revealed histiocytic cells and emperipolesis consistent with RDD. Following surgery, corticosteroid agents were administered, leading to marked resolution of both the remaining surgically untreated lesions and the balance of the patient's symptoms. This report represents the first case of the resolution of intracranial RDD following corticosteroid therapy. Corticosteroid agents should be considered an effective option in the treatment of CNS RDD.
Persistent intracranial hypertension caused by superior sagittal sinus stenosis following depressed skull fracture
Authors: Yokota Hiroshi , Eguchi Takahiko , Nobayashi Misato , Nishioka Toshikazu , Nishimura Fumihiko , Nikaido Yuji
Published: January 2008

✓ Intracranial hypertension caused by a compound depressed skull fracture on the posterior part of the superior sagittal sinus is a rare condition, and nonspecific symptoms and signs can delay appropriate diagnosis and treatment. The authors report on a case of intracranial hypertension that persisted despite conservative treatment, including anticoagulation therapy, which did not improve severe flow disturbance related to the venous sinus compression. Management of this rare condition is discussed and the literature is reviewed.
Presurgical treatment with somatostatin analogs in patients with acromegaly: effects on the remission and complication rates
Authors: Losa Marco , Mortini Pietro , Urbaz Laura , Ribotto Paolo , Castrignanò Tristana , Giovanelli Massimo
Published: January 2008

Object

The question of whether preoperative therapy with somatostatin analogs can improve surgical outcome in acromegaly has not been definitively answered. In this paper, the authors report the effects of preoperative treatment with somatostatin analogs in a large sample of patients with acromegaly.

Methods

Between 1990 and 2003, 399 consecutive patients with acromegaly underwent surgery at the Istituto Scientifico San Raffaele. Thirty-three patients who had previously undergone surgery or radiation treatment, 48 patients treated with somatostatin analogs for fewer than 3 months, and patients who had stopped therapy for too long a time before surgery were excluded from the study. One hundred forty-three patients who had received somatostatin analogs prior to surgery (Group 1) were randomly matched to 143 patients who had never been treated with somatostatin analogs (Group 2). Matching criteria were tumor size and invasiveness into the cavernous sinus. Before surgery, Group 1 patients showed reduction of growth hormone levels to less than 50% of baseline in 64% of cases, but insulin-like growth factor–I was normalized in only 19.5%. Surgical remission occurred in 81 Group 1 patients (56.6%) and in 91 Group 2 patients (63.6%; p = 0.28). No significant difference in the remission rate was observed when cases were analyzed according to tumor size or invasiveness. Logistic regression analysis confirmed that pretreatment with somatostatin analogs was not associated with surgical outcome. Surgical morbidity was mild and similar in Group 1 and Group 2 patients (7 and 5.6%, respectively; p = 0.81). Surgical remission and complication rates in patients with acromegaly who received treatment with somatostatin analogs prior to surgery were not significantly different from those of matched patients who did not receive these agents.

Conclusions

At present, the routine use of presurgical therapy with somatostatin analogs for patients with acromegaly cannot be recommended.
Local control of brain metastases by stereotactic radiosurgery in relation to dose to the tumor margin
Authors: Vogelbaum Michael A. , Angelov Lilyana , Lee Shih-Yuan , Li Liang , Barnett Gene H. , Suh John H.
Published: January 2008

Object

The maximal tolerated dose (MTD) for stereotactic radiosurgery (SRS) for brain tumors was established by the Radiation Therapy Oncology Group (RTOG) in protocol 90-05, which defined three dose groups based on the maximal tumor diameter. The goal in this retrospective study was to determine whether differences in doses to the margins of brain metastases affect the ability of SRS to achieve local control.

Methods

Between 1997 and 2003, 202 patients harboring 375 tumors that met study entry criteria underwent SRS for treatment of one or multiple brain metastases. The median overall follow-up duration was 10.7 months (range 3–83 months). A dose of 24 Gy to the tumor margin had a significantly lower risk of local failure than 15 or 18 Gy (p = 0.0005; hazard ratio 0.277, confidence interval [CI] 0.134–0.573), whereas the 15- and 18-Gy groups were not significantly different from each other (p = 0.82) in this regard. The 1-year local control rate was 85% (95% CI 78–92%) in tumors treated with 24 Gy, compared with 49% (CI 30–68%) in tumors treated with 18 Gy and 45% (CI 23–67%) in tumors treated with 15 Gy. Overall patient survival was independent of dose to the tumor margin.

Conclusions

Use of the RTOG 90-05 dosing scheme for brain metastases is associated with a variable local control rate. Tumors larger than 2 cm are less effectively controlled than smaller lesions, which can be safely treated with 24 Gy. Prospective evaluations of the relationship between dose to the tumor margin and local control should be performed to confirm these observations.
Pituitary apoplexy: do histological features influence the clinical presentation and outcome?
Authors: Semple Patrick L. , de Villiers Jacques C. , Bowen Robert M. , Lopes M. Beatriz S. , Laws Edward R.
Published: January 2008

Object

A retrospective analysis of a contemporary series of patients with pituitary apoplexy was performed to ascertain whether the histopathological features influence the clinical presentation or the outcome.

Methods

A retrospective analysis was performed in 59 patients treated for pituitary apoplexy at the University of Virginia Health System, Charlottesville, Virginia, or Groote Schuur Hospital, University of Cape Town, South Africa. The patients were divided into two groups according to the histological features of their disease: one group with infarction alone, comprising 22 patients; and the other with hemorrhagic infarction and/or frank hemorrhage, comprising 37 patients. The presenting symptoms, clinical features, endocrinological status, and outcome were compared between the two groups.

Conclusions

The patients who presented with histological features of pituitary tumor infarction alone had less severe clinical features on presentation, a longer course prior to presentation, and a better outcome than those presenting with hemorrhagic infarction or frank hemorrhage. The endocrine replacement requirements were similar in both groups.
Hemichorea due to hemodynamic ischemia associated with extracranial carotid artery stenosis
Authors: Morigaki Ryoma , Uno Masaaki , Suzue Atsuhiko , Nagahiro Shinji
Published: January 2008

✓ In this paper the authors describe two patients with recurrent hemiparesis and limb shaking that gradually progressed to hemichorea. Cerebral angiography confirmed severe unilateral internal carotid artery stenosis (95%) contra-lateral to the hemichorea. The cerebral blood flow, assessed using N-isopropyl-p-(iodine-123) iodoamphetamine single-photon emission computed tomography (SPECT), disclosed markedly decreased vascular reserves in both patients. After carotid endarterectomy was performed, the hemichorea gradually subsided and SPECT confirmed increased cerebral perfusion. The results in these cases indicate that surgical revascularization is effective for hemichorea due to cerebral ischemia with reduced vascular reserve.
Prospective analysis of prevalence, distribution, and rate of recovery of left ventricular systolic dysfunction in patients with subarachnoid hemorrhage
Authors: Banki Nader , Kopelnik Alexander , Tung Poyee , Lawton Michael T. , Gress Daryl , Drew Barbara , Dae Michael , Foster Elyse , Parmley William , Zaroff Jonathan
Published: January 2008

Object

Subarachnoid hemorrhage (SAH) has been associated with cardiac injury and left ventricular (LV) dysfunction. The incidence and natural history of neurocardiogenic injury after SAH remains poorly understood. The objective of this study was to describe the incidence, time course, recovery rate, and segmental patterns of LV dysfunction after SAH.

Methods

Echocardiography was performed three times over a 7-day period in 173 patients with SAH. The incidence of global (ejection fraction [EF] < 50%) and segmental (any regional wall-motion abnormality [RWMA]) LV dysfunction was measured. The time course of LV dysfunction was determined by comparing the prevalence of LVEF less than 50% and RWMA at 0 to 2, 3 to 5, and 6 to 8 days after SAH. The recovery rate was defined as the proportion of patients with partial or complete normalization of function. The distribution of RWMAs among 16 LV segments was also determined. An LVEF less than 50% was found in 15% of patients, and 13% had an RWMA with a normal LVEF. There was a trend toward increased dysfunction at 0 to 2 days after SAH, compared with 3 to 8 days after SAH. Recovery of LV function was observed in 66% of patients. The most frequently abnormal LV segments were the basal and middle ventricular portions of the anteroseptal and anterior walls. The apex was rarely affected.

Conclusions

Left ventricular systolic dysfunction occurs frequently after SAH and usually improves over time. The observed segmental patterns of LV dysfunction often do not correlate with coronary artery distributions.
Altered expression of connexin subtypes in mesial temporal lobe epilepsy in humans
Authors: Collignon Frederic , Wetjen Nicholas M. , Cohen-Gadol Aaron A. , Cascino Gregory D. , Parisi Joseph , Meyer Fredric B. , Marsh W. Richard , Roche Patrick , Weigand Stephen D.
Published: January 2008

Object

The causes of epileptic events remain unclear. Much in vitro and in vivo experimental evidence suggests that gap junctions formed by connexins (Cxs) between neurons and/or astrocytes contribute to the generation and maintenance of seizures; however, few experiments have been conducted in humans, and those completed have shown controversial data. The authors designed a study to compare the level of expression of Cxs in hippocampi from epileptic and nonepileptic patients to assess whether an alteration of gap junction expression in epileptic tissue plays a role in seizure origin and propagation.

Methods

The expression of Cxs32, -36, and -43 was studied in 47 consecutive samples of hippocampi obtained from epileptic patients who had undergone an amygdalohippocampectomy for the treatment of intractable seizure. These expression levels were compared with those in hippocampi obtained in nonepileptic patients during postmortem dissection. Immunostaining was performed to create one slide for each of the three Cxs. Each slide demonstrated multiple cells from each of six regions (CA1, CA2, CA3, CA4, dentate gyrus, and subiculum). Two independent reviewers rated each Cx–region combination according to an immunoreactive score.

Across all three measures—that is, staining intensity, percentage of positively stained cells, and immunoreactive score—Cx32 appeared to be expressed at a significantly lower level in the epileptic patients compared with controls (p < 0.001 for each measure), whereas Cx43 appeared to be expressed more among the epileptic patients (p < 0.001 for each measure). There was no evidence of any differential expression of Cx36. There was, however, regional variation within each Cx subtype. For Cx36, the staining intensity was higher in the CA2 region in the epilepsy group.

Conclusions

The increase in Cx43, decrease in Cx32, and preservation of Cx36 expression in hippocampi from epileptic persons could play a role in the development of seizures in patients with temporal sclerosis. Additional studies must be completed to understand this mechanism better.
Results of a phase II trial of the GliaSite Radiation Therapy System for the treatment of newly diagnosed, resected single brain metastases
Authors: Rogers Lisa R. , Rock Jack P. , Sills Allen K. , Vogelbaum Michael A. , Suh John H. , Ellis Thomas L. , Stieber Volker W. , Asher Anthony L. , Fraser Robert W. , Billingsley Judith S. , Lewis Paul , Schellingerhout Dawid , _ _ , Shaw Edward G.
Published: January 2008

Object

The aim of this study was to evaluate the effectiveness of brachytherapy using the GliaSite Radiation Therapy System in patients with a newly diagnosed resected single brain metastasis. The primary end point of the study was local tumor control. The secondary end points included patient survival, distant brain recurrence, quality of life, and treatment toxicity.

Methods

The authors conducted a prospective multiinstitutional phase II study of GliaSite brachytherapy prescribed at a 60-Gy dose administered to a 1-cm depth after resection of a single brain metastasis. No whole-brain radiation therapy was given. Patients were assessed at 1 and 3 months after brachytherapy and every 3 months thereafter for up to 2 years.

Seventy-one patients were enrolled at 13 centers. A GliaSite balloon catheter was implanted in 62 patients. Fifty-four patients received brachytherapy. The median patient age was 60 years. The most common tumor (54%) was non–small cell lung cancer. Fifty-seven percent of patients had brain metastasis only, whereas 43% had extracranial metastasis. The median final administered dose was 60 Gy. The magnetic resonance imaging–determined local control rate, based on several different methods, was 82 to 87%. Both the median patient survival time and the median duration of functional independence were 40 weeks. Among the 35 patients who died, the cause of death was neurological in 11%. Thirteen patients underwent reoperation for suspected tumor recurrence or radiation necrosis, and histological diagnoses included radiation necrosis without tumor (nine patients), radiation necrosis mixed with tumor (two patients), and tumor only (two patients). Extracranial metastasis, tumor size, and radiation necrosis were significant factors affecting patient survival.

Conclusions

In patients with a resected single brain metastasis, GliaSite brachytherapy leads to a local control rate, median patient survival time, and duration of functional independence similar to those achieved with resection plus whole-brain radiation therapy.
Lysis of intracerebral hematoma with stereotactically implanted tissue plasminogen activator polymers in a rabbit model
Authors: Thai Quoc-Anh , Pradilla Gustavo , Legnani Federico G. , Kretzer Ryan M. , Hsu Wesley , Tamargo Rafael J.
Published: January 2008

Object

Currently no adequate surgical treatment exists for spontaneous intracerebral hemorrhage (ICH). Implantable polymers can be used effectively to deliver therapeutic agents to the local site of the pathological process, thus reducing adverse systemic effects. The authors report the use of stereotactically implanted polymers loaded with tissue plasminogen activator (tPA) to induce lysis of ICH in a rabbit model.

Methods

Ethylene vinyl acetate (EVAc) polymers were loaded with bovine serum albumin (BSA) only or with BSA plus tPA. In vitro pharmacokinetic (three polymers) and thrombolysis (12 polymers) studies were performed. For the in vivo study, 12 rabbits were fixed in a stereotactic frame, and 0.2 ml of clotted autologous blood was injected into the right frontal lobe parenchyma. After 20 minutes, control BSA polymers were stereotactically implanted at the hemorrhage site in six rabbits, and experimental BSA plus tPA polymers were implanted in six rabbits. Animals were killed at 3 days, and blood clot volume was assessed.

The pharmacokinetic study showed release of 146 ng of tPA over 3 days. The tPA activity correlated with in vitro thrombolysis. In the in vivo study, the six animals treated with tPA polymers had a mean (± standard error of the mean [SEM]) thrombus volume of 1.43 ± 0.29 mm3 at 3 days, whereas the six animals treated with blank (BSA-only) polymers had a mean (± SEM) thrombus volume of 19.99 ± 3.74 mm3 (p < 0.001).

Conclusions

Ethylene vinyl acetate polymers release tPA over the course of 3 days. Stereotactic implantation of tPA-loaded EVAc polymers significantly reduced ICH volume. Polymers loaded with tPA may be useful clinically for lysis of ICH without the side effects of systemic administration of tPA.
Intraoperative ventricular puncture during supraorbital craniotomy via an eyebrow incision
Authors: Menovsky Tomas , de Vries Joost , Wurzer Johannes A. L. , Grotenhuis J. Andre
Published: January 2008

✓ The authors determined the landmarks and coordinates for intraoperative ventricular puncture directly from the supraorbital craniotomy opening via an eyebrow incision.

Fifty magnetic resonance (MR) imaging studies were obtained from patients with no pathological cerebral characteristics or ventricular distortion. The cerebral entry point of the ventriculostomy was located directly under the key bur hole (just behind the zygomatic process of the frontal bone) at the base of the frontal lobe because it represents a stable, reliable point that can be used as the bur hole during supraorbital craniotomy via an eyebrow incision. From this point, the coordinates for lateral ventricular puncture were determined using MR imaging studies and neuronavigational software.

The cerebral entry point of the ventriculostomy was situated directly under the key bur hole at the base of the frontal lobe. The catheter was directed at a 45° angle to the midline and a 20° angle up from an imaginary line parallel to the orbitomeatal line. The catheter will usually be inserted into the ventricle at a point 5 cm deep to the cortex and may be inserted as deep as 6.5 cm. Using this technique, the frontal horn of the lateral ventricle can be easily tapped. The landmark required for this technique is readily available in all patients.
Outcome of carotid endarterectomy and stent insertion based on grading of carotid endarterectomy risk: a 7-year prospective study
Authors: Iihara Koji , Murao Kenichi , Sakai Nobuyuki , Yamada Naoaki , Nagata Izumi , Miyamoto Susumu
Published: January 2008

Object

The authors of this study prospectively compared periprocedural neurological morbidity and the appearance of lesions on diffusion-weighted (DW) magnetic resonance (MR) imaging in patients who had undergone carotid endarterectomy (CEA) or carotid artery stent placement (CASP) with distal balloon protection, based on a CEA risk grading scale.

Methods

Patients undergoing CEA (139 patients) and CASP (92 patients) were classified into Grades I to IV, based on the presence of angiographic (Grade II), medical (Grade III), and neurological (Grade IV) risks. Although not randomized, the CEA and CASP groups were well matched in terms of the graded risk factors except for a greater proportion of neurologically unstable patients in the CEA group (11 compared with 3%, p = 0.037). There were greater proportions of asymptomatic (64 compared with 34%, p = 0.006) and North American Symptomatic Carotid Endarterectomy Trial–ineligible patients (29 compared with 14%, p < 0.0001) in the CASP group. The overall rates of neurological morbidity with ischemic origin and the appearance of lesions on DW MR imaging after CEA were 2.2 and 9.3%, and those after CASP were 7.6 and 35.9% (nondisabling stroke only), respectively. The only disabling stroke was caused by an intracerebral hemorrhage attributable to hyperperfusion in one case (0.7%) of CEA. There were no deaths. There was no significant association between neurological morbidity and the risk grade in patients who had undergone CEA, although the incidence of lesions on DW imaging was significantly greater in the Grade IV risk group compared with that in the other risk groups combined (42.1 compared with 4.2%, p < 0.0001). After CASP, a higher incidence of neurological morbidity and lesions on DW imaging was noted for the Grade II and III risk groups combined as compared with that in the Grade I risk group, regardless of a symptomatic or an asymptomatic presentation (neurological morbidity: 10.5 compared with 3.1%, respectively, p = 0.41; and DW imaging lesions: 47.4 compared with 19.4%, p = 0.01). The incidence of lesions on DW imaging after CEA was significantly lower than that after CASP except for the Grade IV risk groups.

Conclusions

Despite a higher incidence of DW imaging–demonstrated lesions in the Grade IV risk group, there was no significant association between the risk group and neurological morbidity rates after CEA. The presence of vascular and medical risk profiles conferred higher rates of neurological morbidity and an increased incidence of lesions on DW imaging after CASP. Considering that no serious nonneurological complications were noted, CEA and CASP appear to be complementary methods of revascularization for carotid artery stenosis with various risk profiles.