bluuebunny/crossref_metadata_2025 huggingface dataset:
Cigarette smoking as a cause of aneurysmal subarachnoid hemorrhage and risk for vasospasm: a report of the Cooperative Aneurysm Study
Authors: Weir Bryce K. A. , Kongable Gail L. , Kassell Neal F. , Schultz John R. , Truskowski Laura L. , Sigrest Ashley , _ _
Published: June 2009

Object. Cigarette smoking is associated with aneurysmal subarachnoid hemorrhage (SAH) and subsequent vasospasm. The purpose of this study was to quantify this association.

Methods. Nearly 3500 patients with SAH from North America and Europe have been enrolled in five different multicenter, controlled studies coordinated at the Neuroclinical Trials Center of the Virginia Neurological Institute at the University of Virginia. Among the prospective data gathered were whether the patient smoked at the time of their most recent SAH and the evolution of angiographic vasospasm. The rate of smoking in the patients enrolled in the studies was compared with the expected rate by using a chi-square statistic adjusted for age and gender, in the general population in the United States (U.S.) and Europe. In virtually all age and gender subgroups, and for the combined populations in the five clinical trials, patients with SAH reported current smoking rates 2.5 times higher than expected based on U.S. and European national surveys (p < 0.0001). Cigarette smoking was also associated with younger age at onset of SAH (5–10 years, p < 0.0001) and increased incidence of clinically confirmed vasospasm (p < 0.005).

Conclusions. The findings of a significantly increased representation of current cigarette smokers in the study populations and significant association with younger age at the time of SAH and increased incidence of vasospasm concur with recent reports of smoking as a significant risk factor for ruptured aneurysms and subsequent vasospasm.
Late postirradiation occlusive vasculopathy in childhood medulloblastoma
Authors: Grenier Yannick , Tomita Tadanori , Marymont MaryAnne H. , Byrd Sharon , Burrowes Delilah M.
Published: June 2009

✓ The authors report two cases of ischemic stroke secondary to occlusive vasculopathy two decades after radiation therapy (RT) for medulloblastoma. Both patients underwent posterior fossa medulloblastoma partial resection, followed by craniospinal RT in which a cobalt 60 source was used; 40 Gy were given to the whole brain plus a 15-Gy boost to the posterior fossa. Both patients received multiagent chemotherapy, immediately following radiation therapy in the first case and after repeated craniotomy for recurrence 13 years after radiation in the second case. They experienced multiple sequelae from radiation and chemotherapy, including growth retardation and psychomotor delay. However, 20 years after treatment, they remained tumor free and able to work, until they presented with focal neurological deficits and seizures. Computerized tomography and magnetic resonance imaging of the brain in both cases showed no tumor recurrence, but did demonstrate ischemia in a posterior cerebral artery distribution. Cerebral angiography revealed multiple mid-sized arterial wall irregularities as well as focal stenoses consistent with a postirradiation vasculopathy. The pathophysiological mechanisms, radiological appearance, and incidence of this syndrome are reviewed from the literature.
Giant intracranial and extracranial cavernous malformation
Authors: Voelker Joseph L. , Stewart Daniel H. , Schochet Sydney S.
Published: June 2009

✓ Massive enlargement of an extracerebral cavernous malformation and extension across tissue planes is very uncommon. The authors present the case of a 49-year-old woman with a giant cavernous malformation in the left frontotemporal area. It progressively enlarged during several decades, extended through the calvaria to the extradural space, and was surgically treated. The lesion may have originated in the soft tissue or the skull. The locations of cavernous malformations in various parts of the body are reviewed and their mechanisms of growth are discussed. Surgical excision is the treatment of choice.
Giant aneurysms of the middle cerebral artery trifurcation treated with extracranial—intracranial arterial bypass and endovascular occlusion
Authors: Weill Alain , Cognard Christophe , Levy David , Robert Gilles , Moret Jacques
Published: June 2009

✓ Giant middle cerebral artery (MCA) trifurcation aneurysms that cannot be excluded directly can be treated by flow inversion achieved by creation of an extracranial—intracranial bypass distal to the aneurysm, followed by occlusion of the parent vessel proximal to the aneurysm. As opposed to surgical occlusion, endovascular occlusion avoids dissection of the aneurysm area, and the site of occlusion can be chosen according to the flow distribution demonstrated on angiography performed during test occlusions.

Two patients with giant aneurysms of the MCA trifurcation benefited from flow inversion treatment. Forty-eight hours after an MCA—superficial temporal artery bypass had been created, the M1 segment was occluded by inserting a coil in the first patient and the internal carotid artery was occluded with balloons in the second patient (there was no communicating artery in the latter case). Both occlusions were performed immediately after a clinical test of occlusion tolerance.

The patients were clinically intact during the postoperative course. Follow-up angiography performed 11 and 4 months, respectively, after vessel occlusion showed that the aneurysm occlusion was stable.
Arterial aneurysms associated with cerebral arteriovenous malformations: classification, incidence, and risk of hemorrhage
Authors: Redekop Gary , TerBrugge Karel , Montanera Walter , Willinsky Robert
Published: June 2009

Object. The goal of this study was to develop a classification system for aneurysms associated with arteriovenous malformations (AVMs) based on their anatomical and pathophysiological relationships and to determine the incidence and bleeding rates for these aneurysms as well as the effects of AVM treatment on their natural history.

Methods. Of 632 patients with AVMs, intranidal aneurysms were found in 35 (5.5%) and flow-related aneurysms in 71 (11.2%). Patients with intranidal aneurysms presented more frequently with hemorrhage (72% compared with 40%, p < 0.001) and had a 9.8% per year risk rate of bleeding during follow-up review. Twelve (17%) of the patients with flow-related aneurysms associated with an AVM presented with hemorrhage from an aneurysm, whereas 15 (21%) bled from their AVM. Seventeen patients underwent angiography after AVM treatment (mean 2.25 years). Of 23 proximal aneurysms, 18 (78.3%) were unchanged, four (17.4%) were smaller, and one (4.3%) had disappeared, whereas four (80%) of five distal aneurysms regressed completely and one was unchanged. Sixteen patients underwent angiography after partial AVM treatment (mean 3.8 years). In cases with less than a 50% reduction in the AVM, no aneurysms regressed, although two enlarged and bled. In cases with greater than a 50% reduction in the AVM, two of three distal aneurysms disappeared and five proximal aneurysms were unchanged.

Conclusions. Arterial aneurysms associated with cerebral AVMs may be classified as intranidal, flow-related, or unrelated to the AVM nidus. Intranidal aneurysms have a high correlation with hemorrhagic clinical presentation and a risk of bleeding during the follow-up period that considerably exceeds that which would be expected in their absence. Patients with flow-related aneurysms in association with an AVM may present with hemorrhage from either lesion. Aneurysms that arise on distal feeding arteries near the nidus have a high probability of regressing with substantial or curative AVM therapy.
The descriptive epidemiology of craniopharyngioma
Authors: Bunin Greta R. , Surawicz Tanya S. , Witman Philip A. , Preston-Martin Susan , Davis Faith , Bruner Janet M.
Published: June 2009

Object. In this report the authors describe the epidemiology of craniopharyngioma.

Methods. The incidence of craniopharyngioma in the United States was estimated from two population-based cancer registries that include brain tumors of benign and borderline malignancy: the Central Brain Tumor Registry of the United States (CBTRUS) and the Los Angeles county Cancer Surveillance Program. Information on additional pediatric tumors was available from the Greater Delaware Valley Pediatric Tumor Registry (GDVPTR). The overall incidence of craniopharyngioma was 0.13 per 100,000 person years and did not vary by gender or race. A bimodal distribution by age was noted with peak incidence rates in children (aged 5–14 years) and among older adults (aged 65–74 years in CBTRUS and 50–74 years in Los Angeles county). Survival information was available from GDVPTR and the National Cancer Data Base (NCDB), a hospital-based reporting system. In the NCDB, the 5-year survival rate was 80% and decreased with older age at diagnosis. Survival is higher among children and has improved in recent years.

Conclusions. Craniopharyngioma is a rare brain tumor of uncertain behavior that occurs at a rate of 1.3 per million person years. Approximately 338 cases of this disease are expected to occur annually in the United States, with 96 occurring in children from 0 to 14 years of age.
Occlusion of the sigmoid sinus after surgery via the presigmoidal—transpetrosal approach
Authors: Ohata Kenji , Haque Moududul , Morino Michiharu , Nagai Kenji , Nishio Akimasa , Nishijima Yoshihiko , Hakuba Akira
Published: June 2009

Object. In this paper the authors report on sigmoid sinus occlusion as a surgical complication in seven of 143 operations in which a presigmoidal—transpetrosal approach was used.

Methods. Five patients (Cases 1–5) developed occlusion within 40 days after surgery, and in the remaining two (Cases 6 and 7) occlusion was detected 5.4 and 6.4 years postsurgery by means of cerebral venography, which was performed in 40 of the remaining 138 patients. Of the two patients with occlusion of the hypoplastic transverse sinus, one (Case 1) did not develop symptoms and the other (Case 2) developed brain edema with transient aphasia. Of the three patients suffering from occlusion of the dominant sigmoid sinus, one (Case 3) developed severe intracerebral hemorrhages and had a poor prognosis; one (Case 4) developed profuse supra- and infratentorial brain edema with consciousness disturbance; and the other (Case 5) developed hemorrhagic infarction in the temporal lobe accompanied by aphasia. Two patients whose sinus occlusion was detected later (Cases 6 and 7) did not develop symptoms and displayed well-communicated transverse sinuses. In Case 7, a dural arteriovenous malformation formed at the site of the sinus occlusion. Laceration of the sigmoid sinus was suspected as the cause of occlusion in Cases 2, 3, and 7; compression of the sinus in Cases 5 and 6, sinus laceration and postoperative dehydration in Case 4; and laceration and compression of the sinus in Case 1.

Conclusions. Differences in the clinical course among these patients were attributed to anatomical variations in the venous system. Occlusion of the sigmoid sinus should be weighed as a potential complication when selecting candidates for the presigmoidal—transpetrosal approach.
Poststroke pain control by chronic motor cortex stimulation: neurological characteristics predicting a favorable response
Authors: Katayama Yoichi , Fukaya Chikashi , Yamamoto Takamitsu
Published: June 2009

Object. The goal of this study was to identify the neurological characteristics of patients with poststroke pain who show a favorable response to motor cortex (MC) stimulation used to control their pain.

Methods. The neurological characteristics of 31 patients treated by MC stimulation were analyzed. In 15 patients (48%), excellent or good pain control (pain reduction > 60%) was achieved for follow-up periods of more than 2 years by using MC stimulation at intensities below the threshold for muscle contraction. Satisfactory pain control was achieved in 13 (73%) of 18 patients in whom motor weakness in the painful area was virtually absent or mild, but in only two (15%) of the 13 patients who demonstrated moderate or severe weakness in the painful area (p < 0.01). Muscle contraction was inducible in the painful area in 20 patients when stimulated at a higher intensity. No such muscle response was inducible in the remaining 11 patients, no matter how extensively the authors attempted to determine appropriate stimulation sites. Satisfactory pain control was achieved in 14 (70%) of the 20 patients in whom muscle contraction was inducible, but in only one (9%) of the 11 patients in whom muscle contraction was not inducible (p < 0.01). No significant relationship was observed between pain control and various sensory symptoms, including the presence of hypesthesia, spontaneous dysesthesia, hyperpathia, and allodynia, or the disappearance of the N20 component of the median nerve—evoked somatosensory scalp potential. No significant relationship existed between the effect of MC stimulation on the pain and stimulation-induced phenomena, including paresthesia, improvement in motor performance, and attenuation of involuntary movements.

Conclusions. These findings suggest that the pain control afforded by MC stimulation requires neuronal circuits that are maintained by the presence of intact corticospinal tract neurons originating from the MC. Preoperative evaluation of motor weakness of the painful area appears to be useful for predicting a favorable response to MC stimulation in the control of poststroke pain.
Direct convective delivery of macromolecules to the spinal cord
Authors: Lonser Russell R. , Gogate Nitin , Morrison Paul F. , Wood J. David , Oldfield Edward H.
Published: June 2009

Object.Because of the limited penetration of macromolecules across the blood—spinal cord barrier, numerous therapeutic compounds with potential for treating spinal cord disorders cannot be used effectively. The authors have developed a technique to deliver and distribute macromolecules regionally in the spinal cord by using convection in the interstitial space.

Methods.The authors designed a delivery system connected to a “floating” silica cannula (inner diameter 100 µm, outer diameter 170 µm) that provides for constant volumetric inflow to the spinal cord. A solution containing albumin that was either unlabeled or labeled with carbon-14 or gadolinium was infused at various volumes (3, 6, 10, 20, 40, or 50 µl) at a rate of 0.1 µl/minute into the spinal cord dorsal columns of nine swine and into the lateral columns of three primates(Macaca mulatta). Volume of distribution (Vd), concentration homogeneity, and percentage of recovery were determined using scintillation analysis, kurtosis calculation (K), and quantitative autoradiography (six swine), magnetic resonance imaging (one swine and three primates), and histological analysis (all animals). Neurological function was observed for up to 3 days in four of the swine and up to 16 weeks in the three primates.

The Vd of14C-albumin was linearly proportional (R2= 0.97) to the volume of infusion (Vi) (Vd/Vi = 4.4 ± 0.5; [mean ± standard deviation]). The increases in Vd resulting from increases in Vi were primarily in the longitudinal dimension (R2= 0.83 in swine; R2= 0.98 in primates), allowing large segments of spinal cord (up to 4.3 cm; Vi 50 µl) to be perfused with the macromolecule. The concentration across the area of distribution was homogeneous (K = −1.1). The mean recovery of infused albumin from the spinal cord was 85.5 ± 5.6%. Magnetic resonance imaging and histological analysis combined with quantitative autoradiography revealed the albumin infusate to be preferentially distributed along the white matter tracts. No animal exhibited a neurological deficit as a result of the infusion.

Conclusions.Regional convective delivery provides reproducible, safe, region-specific, and homogeneous distribution of macromolecules over large longitudinal segments of the spinal cord. This delivery method overcomes many of the obstacles associated with current delivery techniques and provides for research into new treatments of various conditions of the spinal cord.
Role of transforming growth factor—β1 in the pathogenesis of moyamoya disease
Authors: Hojo Masato , Hoshimaru Minoru , Miyamoto Susumu , Taki Waro , Nagata Izumi , Asahi Minoru , Matsuura Nobuki , Ishizaki Ryuji , Kikuchi Haruhiko , Hashimoto Nobuo
Published: June 2009

Object. Prominent features of moyamoya disease are intimal thickening of the cerebral arterial trunks and abundant angiogenesis for collateral blood supplies, but its pathogenesis is still unknown. The aim of this study was to test the possibility that transforming growth factor—β1 (TGFβ1) may play a role in the pathogenesis of moyamoya disease.

Methods. The authors used reverse transcription—polymerase chain reaction to analyze the expression level of TGFβ1 in smooth-muscle cells cultured from the superficial temporal arteries (STAs) and measured the serum level of TGFβ1 by using enzyme-linked immunosorbent assay. Although the STA is not predominantly involved with moyamoya disease, it has been used in studies of the pathogenesis of this disease. In this report, the STAs from six patients with moyamoya disease and four with arteriosclerotic cerebrovascular disease, along with sera from 14 patients with moyamoya disease and 10 normal healthy volunteers, were studied. The expression of TGFβ1 was significantly higher in cultured smooth-muscle cells derived from the STAs of patients with moyamoya disease than in those derived from the STAs of patients with arteriosclerotic cerebrovascular disease (p < 0.05). The serum level of TGFβ1 was also significantly higher in patients with moyamoya disease than in controls (p < 0.0005).

Conclusions. Taking into account the functional roles of TGFβ1 in the expression of connective tissue genes and angiogenesis, these investigators suggest that TGFβ1 is associated with the pathogenesis of moyamoya disease, including abundant neovascularization, although their findings do not necessarily mean that TGFβ1 is a causative factor in this disease.
Neuroradiological findings in adult cranially conjoined twins
Authors: Jansen Olav , Mehrabi V. A. , Sartor Klaus
Published: June 2009

✓ The authors demonstrate the radiological anatomy and review the accepted embryological theories in a case of total craniopagus. These 24-year-old female cranially conjoined twins were studied with computerized tomography (CT) and CT angiography, magnetic resonance (MR) imaging and MR angiography as well as selective arterial digital subtraction (DS) angiography to clarify whether surgical separation was possible. The neuroradiological findings are discussed, taking into consideration both the embryological and surgical literature.

The malformation was classified as a total parietooccipitotemporal craniopagus. Whereas CT angiography and MR imaging including MR angiography demonstrated a common superior sagittal sinus, only selective arterial DS angiography revealed a significant arterial and venous cross-flow between the two adjacent temporal lobes. Selective intraarterial DS angiography is required in the neuroradiological evaluation of complex malformations, even when the anatomy of brain and skull can be well demonstrated with high-quality MR and CT studies.
Detection of Bartonella henselae by polymerase chain reaction in brain tissue of an immunocompromised patient with multiple enhancing lesions
Authors: George Tracy I. , Manley Geoffrey , Koehler Jane E. , Hung Virginia S. , McDermott Michael , Bollen Andrew
Published: June 2009

✓ The authors report the first DNA-based diagnosis of Bartonella henselae cultured from a brain lesion in a patient with acquired immune deficiency syndrome. This human immunodeficiency virus—infected patient presented with altered mental status, fever, and diabetes insipidus. Magnetic resonance imaging revealed multifocal parenchymal and leptomeningeal involvement, which was confirmed on studies of tissue biopsy samples. Using the polymerase chain reaction and gene sequencing techniques, the authors definitively demonstrated the presence of B. henselae in the brain tissue biopsy specimen.
Continuous hemodialysis for the management of acute renal failure in the presence of cerebellar hemorrhage
Authors: Caruso Daniel M. , Vishteh A. Giancarlo , Greene Karl A. , Matthews Marc R. , Carrion Carlos A.
Published: June 2009

✓ In this report the authors describe the use of continuous venovenous hemodialysis (CVVHD) in a medically unstable patient who suffered from a spontaneous cerebellar hemorrhage.

Conventional dialysis techniques carry the risk of developing the dialysis disequilibrium syndrome (DDS) when performed in the presence of a variety of intracranial diseases. The CVVHD technique was used successfully in a morbidly obese, short-statured woman with a spontaneous hypertensive intraparenchymal cerebellar hemorrhage. The woman experienced acute renal failure several days after her hemorrhage and her general medical condition prevented her from undergoing surgical evacuation. The CVVHD did not result in elevations in intracranial pressure (ICP) and the patient made a full recovery from both acute renal failure and life-threatening posterior fossa hemorrhage.

This case is noteworthy because of the absence of abnormally high ICP elevations or development of DDS in a patient with a large acute posterior fossa intraparenchymal brain hemorrhage and acute renal failure whose case was managed with CVVHD in the acute period.
Death from a malignant cerebellopontine angle triton tumor despite stereotactic radiosurgery
Authors: Comey Christopher H. , McLaughlin Mark R. , Jho Hae Dong , Martinez A. Julio , Lunsford L. Dade
Published: June 2009

✓ Malignant vestibular nerve tumors are rare: to date, only three cases have been reported in the literature. The authors report a case of an eighth cranial nerve tumor that progressed 5 years after stereotactic radiosurgery. The patient was a 44-year-old man who underwent stereotactic radiosurgery for a 27-mm cerebellopontine angle tumor that was discovered on investigation of tinnitus and hearing loss. He developed facial weakness after 5 years, and repeated imaging revealed tumor enlargement. Despite complete microsurgical excision, the tumor rapidly recurred locally and subsequently disseminated within the neuraxis. The patient died 1 year after tumor progression was detected.

Histopathological analysis revealed a malignant spindle cell neoplasm with frequent mitotic figures. The presence of positive rhabdoid elements on immunohistochemical studies confirmed that it was a triton tumor. The authors review the relevant literature concerning the classification and management of malignant vestibular nerve tumors and discuss the implications of tumor progression after stereotactic radiosurgery.
Cavernous sinus syndrome during balloon test occlusion of the cervical internal carotid artery
Authors: Lopes Demetrius K. , Mericle Robert A. , Wakhloo Ajay K. , Guterman Lee R. , Hopkins L. Nelson
Published: June 2009

✓ The authors report the occurrence of ipsilateral transient cavernous sinus syndrome during balloon test occlusion (BTO) of the cervical internal carotid artery (ICA) and discuss the involved pathomechanisms.

The authors reviewed their series of 129 BTOs of the ICA performed between 1989 and 1996. Two patients developed facial paresthesias and transient palsies of the third through sixth cranial nerves during test occlusion of the cervical ICA. The tests were performed prior to planned permanent carotid artery occlusion for the treatment of a neck sarcoma in one patient and a giant cavernous carotid artery aneurysm in the other. The patients' symptoms resolved with deflation of the balloon. When the balloon was subsequently inflated above the inferior cavernous sinus artery (ICSA), one of the patients complained of mild facial discomfort. There was no contralateral weakness or mental status change during test occlusion in either patient. Angiography demonstrated good filling of the ipsilateral intracranial circulation via collateral vessels of the circle of Willis.

In these two cases, the cranial nerves in the cavernous sinus were likely supplied by the ICA via the meningohypophyseal trunk and the ICSA. In each case, there was excellent blood supply to the ipsilateral cerebral hemisphere; however, there was probably inadequate retrograde filling of the cranial nerve collateral vessels located where the meningohypophyseal trunk and ICSA originated. These cases emphasize the importance of a patent external carotid artery—ICA connection for successful cervical carotid artery occlusion. Neurological examination during BTO was critical to interpret the clinical manifestations caused by the hemodynamic changes.
Reconstruction of the vein of Labbé by using a short saphenous vein bypass graft
Authors: Morita Akio , Sekhar Laligam N.
Published: June 2009

✓ Protection of the vein of Labbé is a significant concern during surgery that involves retraction of the temporal lobe. A cranial base surgical approach, especially one via the presigmoid—petrosal route, carries considerable risk to this venous complex. A case is presented in which a large dominant vein of Labbé was injured during resection of a petroclival meningioma. This vein drained all the sylvian venous circulation as well as the lateral temporal surface; no connection to another venous system was noted. The vein was successfully reconstructed using a short saphenous vein bypass graft. Significant complications could have occurred without this reconstruction. The technique and benefits of this type of reconstruction are discussed.
Intracranial vascular anastomosis using the microanastomotic system
Authors: Newell David W. , Dailey Andrew T. , Skirboll Stephen L.
Published: June 2009

✓ The authors describe the use of a microanastomotic device to perform intracranial end-to-end vascular anastomoses. Direct end-to-end anastomosis was performed between the superficial temporal artery and branches of the middle cerebral artery (MCA) in three patients. Two patients had moyamoya disease, with severe proximal MCA disease, and one suffered an internal carotid artery occlusion with poor collateral flow. All patients reported a history of recent ischemic symptoms. Each anastomosis was accomplished in less than 15 minutes with technically satisfactory results. Postoperative angiographic studies demonstrated patency of the bypasses in all patients.
Surgical management of ulnar nerve compression at the elbow: an analysis of the literature
Authors: Bartels Ronald H. M. A. , Menovsky Thomas , Van Overbeeke Jacobus J. , Verhagen Wim I. M.
Published: June 2009

Object.Surgical treatment for cubital ulnar nerve compresson includes medial epicondylectomy, simple decompression, or anterior transposition (subcutaneous, intramuscular, or submuscular). There is a dearth of prospective randomized studies on which to base guidelines for choosing one operative treatment over another. The authors review the literature on this subject and present their findings.

Methods.The authors reviewed the literature from January 1970 to July 1997. Two authors decided independently whether an article should be included for review based on previously formulated inclusion and exclusion criteria. In addition to demographic information, data concerning preoperative status and outcome were extracted. For statistical analyses chi-square and Kruskal—Wallis tests were performed.

Irrespective of their preoperative status, patients with simple decompression had the best outcome, whereas those with anterior subcutaneous and submuscular transposition had the worst. If outcome was related to the patient's preoperative status, a significant difference was not found among the various groups for those patients with a preoperative McGowan Grade 2. However, for those with McGowan Grade 3 (severe) symptoms, patients with anterior intramuscular transposition had the best outcome followed by those with simple decompression and anterior submuscular transposition. Statistical analysis was not possible for patients with McGowan Grade 1 because of the small numbers of patients in several treatment modality groups.

Conclusions.Formulating a uniform guideline for operative treatment is not possible based on the results of this study. However, the authors believe that support is given to their policy, which is primarily to perform a simple decompression. Its surgical simplicity with preservation of the anatomy, especially the vascularization, and the possibility of rapid postoperative rehabilitation are also taken into consideration. If subluxation is found intraoperatively, anterior transposition is proposed.
Falcine sinus and occipital encephalocele: a magnetic resonance venography study
Authors: Bartels Ronald H. M. A. , Merx Johannes L. , van Overbeeke Jacobus J.
Published: June 2009

Object.Occipital encephaloceles are relatively frequently encountered. Many investigators have addressed the embryogenesis of these formations, but the dural system has never before been studied. In this retrospective analysis the authors sought to gain a better understanding of the origins of these defects.

Methods.The charts and radiological examinations, especially the magnetic resonance venography studies, were reviewed in seven patients. In six patients the straight sinus was absent. Drainage of the galenic system took place through a sinus within the falx, also known as a falcine sinus. The tentorium was not seen in five patients.

Conclusions.The combination of an absent straight sinus and dysplastic tentorium is no coincidence: both develop within the same mesenchyme in the mesencephalic flexure. Distortion of the mesenchyme by a neural tube defect, causing an occipital encephalocele, will lead not only to disorders of the tentorium but also of the straight sinus.
Focal dilation and paradoxical collapse of cortical fissures and sulci in patients with normal-pressure hydrocephalus
Authors: Holodny Andrei I. , George Ajax E. , de Leon Mony J. , Golomb James , Kalnin Andrew J. , Cooper Paul R.
Published: June 2009

Object.The authors describe a subgroup of patients with shunt-proven normal-pressure hydrocephalus (NPH) who presented with focal fissural and sulcal dilation on imaging studies. The specific radiological features and methods of differentiating this condition from cortical atrophy are delineated.

Methods.Normal-pressure hydrocephalus has been described as dilation of the ventricles that is out of proportion to the sulci. Sulcal dilation has been taken as evidence of cortical atrophy and has even been used as a criterion to exclude patients from undergoing a shunting procedure. The authors describe five cases of patients with shunt-proven NPH who presented with focal dilation of cortical fissures and sulci. In three of the cases, there was a paradoxical decrease in the size of the dilated fissures and sulci that paralleled the decrease in the size of the lateral ventricles following successful shunting.

Conclusions.This study demonstrates that focal fissural and sulcal dilation may represent reservoirs of cerebrospinal fluid analogous to the ventricular system. Patients should not be denied a shunting procedure solely on the basis of focally dilated fissures of sulci.
Oxidative stress in the human brain after subarachnoid hemorrhage
Authors: Gaetani Paolo , Pasqualin Alberto , Rodriguez y Baena Riccardo , Borasio Elena , Marzatico Fulvio
Published: June 2009

Object. The aim of this study was to verify the patterns of antioxidant enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the human brain after subarachnoid hemorrhage (SAH) to verify whether an “oxidative stress situation” characterizes the brain response to subarachnoid bleeding.

Methods. Forty samples of gyrus rectus or temporal operculum that were obtained during a surgical approach to anterior circulation aneurysms were used for this study. The activity of total SOD, GSH-Px, and the SOD/GSH/Px ratio (which expresses the balance between the production of hydrogen peroxides by dismutation of superoxide radicals and the scavenging potential) were calculated in each case. Twelve samples were obtained from patients who underwent surgery for unruptured aneurysms (control group); 13 samples were obtained during surgical procedures performed within 72 hours of SAH; and 15 samples were obtained during delayed surgical procedures (> 10 days post-SAH). Ten patients presented with clinical deterioration caused by arterial vasospasm. In both SAH groups, the mean total SOD activity was significantly higher than in the control group (p = 0.029). The mean activity of GSH-Px did not differ significantly between the SAH and control groups (p = 0.731). There was a significant increase in the SOD/GSH-Px ratio in both SAH groups, as compared with controls (p < 0.05). There was a significant correlation between the enzymatic activity and the clinical severity of the hemorrhage, with findings of lower values of SOD and, mainly, of the SOD/GSH-Px ratio in the poor-grade patients. The SOD/GSH-Px ratio was 2.14 ± 0.44 in patients who presented with clinical vasospasm and 1.24 ± 0.2 in cases without vasospasm.

Conclusions. The results of this study show an imbalance of the antioxidant enzymatic activities in the human brain after SAH, which is linked to the severity of the initial bleeding and possibly modified by the development of arterial vasospasm.
Dural arteriovenous shunts at the craniocervical junction
Authors: Kinouchi Hiroyuki , Mizoi Kazuo , Takahashi Akira , Nagamine Yoshihide , Koshu Keiji , Yoshimoto Takashi
Published: June 2009

Object. A retrospective analysis was conducted of 10 patients (three women and seven men) who were treated for spinal dural arteriovenous shunts (AVSs) located at the craniocervical junction. This analysis was performed to evaluate the characteristics of this unusual location in contrast with those of the more common thoracic and lumbar AVSs.

Methods. Seven patients presented with subarachnoid hemorrhage (SAH) and one with slowly progressive quadriparesis and dyspnea due to myelopathy. The other two cases were detected incidentally and included a transverse—sigmoid dural AVS and a cerebellar arteriovenous malformation. Angiographic studies revealed that the spinal dural AVSs at the C-1 and/or C-2 levels were fed by the dural branches of the radicular arteries that coursed from the vertebral artery and drained into the medullary veins. Venous drainage was caudally directed in the patient with myelopathy. In contrast, the shunt flow drained mainly into the intracranial venous system in patients with SAH. Furthermore, in four of these patients a varix was found on the draining vein. In all patients, the draining vein was interrupted surgically at the point at which this vessel entered the intradural space, using intraoperative digital subtraction angiography to monitor flow. The postoperative course was uneventful in all patients and no recurrence was confirmed on follow-up angiographic studies obtained in seven patients at 6 months after discharge.

Conclusions. If computerized tomography scanning shows SAH predominantly in the posterior fossa and no abnormalities are found on intracranial four-vessel angiographic study, proximal vertebral angiography should be performed to detect dural AVS at the craniocervical junction. The results of surgical intervention for this disease are quite satisfactory.
Cavernous sinus sampling in patients with adrenocorticotrophic hormone—dependent Cushing's syndrome with emphasis on inter- and intracavernous adrenocorticotrophic hormone gradients
Authors: Teramoto Akira , Yoshida Yoichi , Sanno Naoko , Nemoto Shigeru
Published: June 2009

Object. As an alternative method to inferior petrosal sinus sampling with administration of corticotropin-releasing hormone (CRH), the authors have developed a method of selective venous sampling directly from the cavernous sinus, which is performed using a superselective catheterization technique. The goal of this study is to assess this method.

Methods. Catheterization to the cavernous sinus was performed in 44 patients with clinical and biochemical features of Cushing's syndrome. Forty of these patients in whom there was a definite clinical and/or histological diagnosis were evaluated. In 35 patients, a pituitary microadenoma was detected on magnetic resonance imaging and/or during surgery. Ectopic lesions were suspected in five patients, who later developed nonpituitary tumors.

The central/peripheral (C/P) ratios of adrenocorticotrophic hormone (ACTH) without CRH administration ranged from 5.2 to 448.1 (mean ± standard deviation, 66.7 ± 91.2) in cavernous sinuses and from 1.1 to 52 (mean ± standard deviation, 8.5 ± 9.9) in the inferior petrosal sinuses. The petrosal sinus sampling contained false negative results in eight patients (23%) based on a cutoff point of 2. On the contrary, patients with ectopic lesions did not show any increase in ACTH levels in either sampling portion.

The intercavernous gradients of ACTH, ranging from 1.2 to 506.4, indicated the correct lateralization of microadenoma in the lateral wing in all 30 patients. The interpetrosal gradients, ranging from 1 to 31.4, did not give a sufficient value (≥ 1.4) in four patients (13%) with a lateral lesion. In five cases of midline tumors, the intercavernous and interpetrosal gradients indicated false laterality in three and four cases, respectively.

The intracavernous (posterior—anterior) gradients, ranging from 1.04 to 60.7 (mean 14.9), showed a higher concentration of ACTH in the posterior portion of the sinus in all patients.

Conclusions. These results suggest that 1) cavernous sinus sampling without CRH administration can demonstrate hypersecretion of ACTH from the pitutary gland with a high diagnostic accuracy; 2) intercavernous gradients will indicate the correct lateralization in laterally localized microadenomas; and 3) sampling should be performed from the posterior portion of the cavernous sinus.
Microsurgical anatomy of the artery of Adamkiewicz and its segmental artery
Authors: Alleyne Cargill H. , Cawley C. Michael , Shengelaia George G. , Barrow Daniel L.
Published: June 2009

Object. The blood supply of the lower spinal cord is heavily dependent on the artery of Adamkiewicz, which characteristically originates from one of the thoracolumbar segmental arteries. The aforementioned artery is of enormous clinical, surgical, and radiological importance, and the goal of this study was to elucidate the course and branches of the segmental artery that gives rise to this important vessel.

Methods. In this cadaveric, microsurgical anatomical study, the authors investigate and describe the course and branches of the artery of Adamkiewicz and the segmental branch from which it ultimately originates. A review of the literature is provided.

Conclusions. By documenting the microsurgical anatomy of these important vessels, this study facilitates an understanding of the anatomy that will aid in treatment planning for surgery of various lesions in this area.
Fatal traumatic vertebral artery aneurysm rupture
Authors: Sahjpaul Ramesh L. , Abdulhak Muwaffak M. , Drake Charles G. , Hammond Robert R.
Published: June 2009

✓ The authors present the case of a 34-year-old man struck over the left mastoid region by a hockey puck, who suffered a fatal rupture of a left vertebral artery berry aneurysm. He became apneic within seconds of the injury and had no brainstem reflex within minutes. The postmortem examination showed massive subarachnoid hemorrhage in the posterior fossa and the remnants of a berry aneurysm near the intradural origin of the left vertebral artery, 11 mm proximal to the posterior inferior cerebellar artery. Rupture of a saccular aneurysm as a result of head trauma is rare. This is the first reported case of a posterior circulation aneurysm rupture as a result of head trauma.
Bilateral vocal cord paralysis following anterior cervical discectomy and fusion
Authors: Manski Thomas J. , Wood Michael D. , Dunsker Stewart B.
Published: June 2009

✓ The authors report a rare case of bilateral vocal cord paralysis following anterior cervical discectomy and fusion (ACD/F) in a patient who had a preexisting, clinically silent, and unrecognized unilateral vocal cord paralysis from a remote cardiac surgical procedure. The patient, a 41-year-old woman who developed acute respiratory stridor and respiratory insufficiency at the time of extubation after undergoing a C6–7 ACD/F, required emergency reintubation and ventilation. Otolaryngological evaluation revealed bilateral vocal cord paralysis with one vocal cord showing evidence of acute paralysis and the other showing evidence of chronic paralysis. She eventually required a permanent tracheotomy. The patient had undergone previous cardiac surgical procedures to correct Fallot's tetralogy as a neonate and as a child. At those times, there were no recognized symptoms of transient or permanent vocal cord dysfunction.

This case emphasizes the importance of identifying patients with preexisting unilateral vocal cord paralysis before performing neurosurgical procedures such as ACD/F, which can place the only functioning vocal cord at risk for paralysis. Guidelines for identifying patients with preexisting unilateral vocal cord paralysis and for modifying the surgical procedure for ACD/F to prevent the catastrophic complication of bilateral vocal cord paralysis are discussed.
Vestibular schwannoma management
Authors: Pollock Bruce E. , Lunsford L. Dade , Flickinger John C. , Clyde Brent L. , Kondziolka Douglas
Published: June 2009

Object. The purpose of this study was to analyze patient outcomes and to define the role of radiosurgery in patients who have undergone prior microsurgical resection of their vestibular schwannoma.

Methods. The authors evaluated the pre- and postoperative clinical and neuroimaging characteristics of 76 consecutive patients with 78 vestibular schwannomas who underwent radiosurgery after previous surgical resection. Twenty-nine patients (37% of tumors) had undergone more than one prior resection. Forty-three patients (55% of tumors) had significant impairment of facial nerve function (House—Brackmann Grades III–VI) after their microsurgical procedure; 50% had trigeminal sensory loss, and 96% had poor speech discrimination (< 50%). The median evaluation period following radiosurgery was 43 months (range 12–101 months). Tumor growth control after radiosurgery was achieved in 73 tumors (94%). Six patients underwent additional surgical resection despite radiosurgery (median of 32 months after radiosurgery), and one patient underwent repeated radiosurgery for tumor progression outside the irradiated volume. Eleven (23%) of 47 patients with Grades I to III facial function before radiosurgery developed increased facial weakness after radiosurgery. Eleven patients (14%) developed new trigeminal symptoms.

Conclusions. Radiosurgery proved to be a safe and effective alternative to additional microsurgery in patients in whom the initial microsurgical removal failed. Stereotactic radiosurgery should be considered for all patients who have regrowth or progression of previously surgically treated vestibular schwannomas.
Increase in extracellular glutamate caused by reduced cerebral perfusion pressure and seizures after human traumatic brain injury: a microdialysis study
Authors: Vespa Paul , Prins Mayumi , Ronne-Engstrom Elizabeth , Caron Michael , Shalmon Ehud , Hovda David A. , Martin Neil A. , Becker Donald P.
Published: June 2009

Object. To determine the extent and duration of change in extracellular glutamate levels after human traumatic brain injury (TBI), 17 severely brain injured adults underwent implantation of a cerebral microdialysis probe and systematic sampling was conducted for 1 to 9 days postinjury.

Methods. A total of 772 hourly microdialysis samples were obtained in 17 patients (median Glasgow Coma Scale score 5 ± 2.5, mean age 39.4 ± 20.4 years). The mean (± standard deviation) glutamate levels in the dialysate were evaluated for 9 days, during which the mean peak concentration reached 25.4 ± 13.7 (µM on postinjury Day 3. In each patient transient elevations in glutamate were seen each day. However, these elevations were most commonly seen on Day 3. In all patients there was a mean of 4.5 ± 2.5 transient elevations in glutamate lasting a mean duration of 4.4 ± 4.9 hours. These increases were seen in conjunction with seizure activity. However, in many seizure-free patients the increase in extracellular glutamate occurred when cerebral perfusion pressure was less than 70 mm Hg (p < 0.001). Given the potential injury-induced uncoupling of cerebral blood flow and metabolism after TBI, these increases in extracellular glutamate may reflect a degree of enhanced cellular crisis, which in severe head injury in humans appears to last up to 9 days.

Conclusions. Extracellular neurochemical measurements of excitatory amino acids may provide a marker for secondary insults that can compound human TBI.
Acute ethanol intoxication in a model of traumatic brain injury with hemorrhagic shock: effects on early physiological response
Authors: Zink Brian J. , Sheinberg Michael A. , Wang Xu , Mertz Michelle , Stern Susan A. , Betz A. Lorris
Published: June 2009

Object. Traumatic brain injury (TBI) is exacerbated by hypotension and hypoventilation. Because previous studies have shown a potentiating effect of ethanol (EtOH) on TBI and hemorrhagic shock (HS), the authors investigated the effects of EtOH on the early physiological response to TBI with and without HS.

Methods. Anesthetized swine, weighing approximately 20 kg each, underwent fluid-percussion TBI of 3 atm with or without 30 ml/kg hemorrhage for a period of 30 minutes. The mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure (CPP), cardiac output, cerebral venous oxygen saturation, and metabolic parameters were monitored for 3 hours postinjury. Ventilation and the response to hypercapnia were also measured. Regional cerebral blood flow and renal blood flow were measured using dye-labeled microspheres. Five groups were studied: control, TBI, TBI/EtOH, TBI/HS, and TBI/HS/EtOH. The EtOH (3.5 g) was given intragastrically 100 minutes preinjury.

The TBI/HS/EtOH group demonstrated a 3-hour mortality rate of 56% and postinjury apnea requiring ventilation in 44% of animals compared with 0% in all other groups. Minute ventilation and the hypercapnic ventilatory response were significantly reduced in the postinjury period in the TBI/HS/EtOH group. The animals in this group had significantly lower CPP and cardiac output in the first 60 minutes postinjury, as well as lower renal and cerebral blood flow. Postinjury cerebral venous lactate levels were higher, and cerebral venous pH was lower in the TBI/HS/EtOH group.

Conclusions. In this model of TBI, acute EtOH intoxication in the presence of HS potentiates the physiological and metabolic alterations that may contribute to secondary brain injury.
Microvascular decompression for superior oblique myokymia
Authors: Samii Madjid , Rosahl Steffen K. , Carvalho Gustavo A. , Krzizok Thomas
Published: June 2009

✓ Superior oblique myokymia (SOM) is a rare eye movement disorder presenting as uniocular rotatory microtremor due to intermittent contractions of the superior oblique muscle. Medical treatment usually fails to provide long-term benefit for the patient and has considerable side effects. Surgical alternatives including tenotomy or partial tenectomy of the superior oblique tendon often result in incomplete resolution of the visual symptoms. The authors report a patient who experienced immediate cessation of disabling SOM following microvascular decompression of the fourth nerve at the root exit zone. Temporary double vision at downgaze resolved 5 months after surgery. There was no recurrence of oscillopsia during a follow-up of 22 months to date.

From this single observation it appears likely that vascular compression of the trochlear nerve could be a significant pathophysiological factor contributing to SOM. In the hands of an experienced surgeon, microvascular decompression at the brainstem exit zone of this nerve may evolve as the method of choice for selected cases of disabling SOM.