bluuebunny/crossref_metadata_2025 huggingface dataset:
Meningeal melanocytoma
Authors: Clarke David B. , Leblanc Richard , Bertrand Gilles , Quartey Gilbert R. C. , Snipes G. Jackson
Published: June 2009

✓ Meningeal melanocytomas are rare tumors of the central nervous system that are found almost exclusively in the posterior fossa and spinal cord and whose natural history is poorly defined. In this report, the authors review the clinical presentation, radiological appearance, operative findings, and histological features in two cases of meningeal melanocytoma: one cranial and one spinal.

Two women, aged 21 and 30 years, were admitted to the hospital 60 years apart: the first because of progressive paraplegia and the second because of slowly progressive hearing loss. The first patient had an extradural tumor that was treated by laminectomy, subtotal resection, and postoperative radiotherapy in 1936. Her symptoms recurred 16 years later and she underwent reoperation of the residual tumor, which was found to have an intradural component. The authors' patient, who presented 60 years later, underwent plain and enhanced computerized tomography and magnetic resonance imaging that demonstrated a large posterior fossa lesion indicative of either an acoustic neuroma or a meningioma. She underwent posterior fossa decompression but only partial excision of the tumor could be accomplished because vigorous bleeding limited the extent of the resection. Surgery was followed by radiotherapy. The residual tumor enlarged despite these measures and required repeated resection 6 months later. At the second operation the tumor was much less vascular, perhaps reflecting the effects of radiotherapy, and was removed almost entirely. The patient died 6 months later from an anticoagulant-related cerebellar hemorrhage. In both cases the lesions were jet black, and histological examination revealed melanin-containing hypercellular tumors with rare mitotic figures.

Meningeal melanocytomas are being diagnosed with increased frequency in parallel with improvements in neuroimaging and clarification of histological features. Clinical presentation of patients with these tumors typically occurs in their fifth decade and women are affected twice as often as men. The posterior fossa lesions can mimic acoustic neuromas and meningiomas in location and radiological appearance; however, the internal auditory canal is normal. In the spine, meningeal melanocytomas present with the clinical features of myeloradiculopathy. Diagnosis is made intraoperatively from the gross, jet-black appearance of the tumor and from histological examination. Vascularity, size, and location may render complete resection unfeasible. Because of the tumor's propensity to recur, radiotherapy has been recommended but its role remains to be elucidated.
Intradural neurotropic spread of malignant mesothelioma
Authors: Steel Timothy R. , Allibone James , Revesz Tamas , D'Arrigo Corrado , Crockard H. Alan
Published: June 2009

✓ This 54-year-old man with a history of right-sided malignant mesothelioma presented with signs of a partial spinal cord syndrome. The tumor had invaded the lower trunk of the brachial plexus and spread along the T-1 nerve root beneath the arachnoid onto the spinal cord itself. Mesothelioma, despite its known predilection for local spread, is rarely encountered within the spinal canal. Neurotropism is commonly encountered in facial malignancies; however, it has never been reported to affect the brachial plexus and spinal cord.
Giant lateral sinus pericranii
Authors: Spektor Sergey , Weinberger Gerald , Constantini Shlomo , Gomori John M. , Beni-Adani Liana
Published: June 2009

✓ A case of giant lateral sinus pericranii, which presented in a patient during early childhood as a soft, collapsible mass and gradually grew until it reached 13 × 9 cm when the patient was 36 years of age, is reported. The patient underwent successful surgery and the lesion was totally excised. The results of diagnostic tests (computerized tomography scanning, magnetic resonance imaging, cerebral angiography, and sinusography) and surgery-related problems are presented and discussed.
Disc herniation at T1–2
Authors: Morgan Howard , Abood Christopher
Published: June 2009

✓ In preparing this paper, the authors reviewed their experiences with four cases of T1–2 disc herniation as well as the medical literature on the subject. Intervertebral thoracic disc herniations are uncommon and high thoracic disc herniations are rare. In the upper third of the thoracic spine, T1–2 is the most common level for disc ruptures. Four cases of disc herniation at T1–2 that caused T-1 radiculopathy are reported in this paper. In reviewing the literature on thoracic disc herniation, the authors found 27 cases at the T1–2 level, 23 of which were lateral disc herniations that produced radiculopathy and four of which were central disc herniations that caused myelopathy. The clinical signs and symptoms of T-1 radiculopathy are similar to those of C-8 radiculopathy; however, distinguishing features can frequently be found on neurological examination. The T-1 radiculopathy usually involves weakness of the intrinsic muscles of the hand. The motor deficit of C-8 radiculopathy involves the intrinsic muscles of the hand and most of the flexors and extensors of the fingers and wrist. The T-1 radiculopathy may produce Horner's syndrome (oculosympathetic paralysis) and diminished sensation in the axilla, which are not found with C-8 radiculopathy. In clinical presentation as well as in treatment, the lateral T1–2 disc herniation resembles a cervical disc herniation, whereas the central T1–2 disc herniation displays the usual appearance of a thoracic disc herniation.
Thoracic duct injury during anterior cervical discectomy: a rare complication
Authors: Hart Anna Kristina E. , Greinwald John H. , Shaffrey Christopher I. , Postma Gregory N.
Published: June 2009

✓ Chylous fistula resulting from intraoperative injury to the cervical thoracic duct is well described as a complication of neck dissection. However, injury to the thoracic duct during spinal surgery is rarely reported. The authors present the first case of thoracic duct injury occurring during cervical discectomy and fusion via an anterior approach. The anomalous location of the terminal arch of the thoracic duct in this patient contributed to the complication. The morbidity of chyle leakage is minimized by its early recognition, a thorough understanding of lymphatic system anatomy, and aggressive management of the thoracic duct injury.
Arthur Roland Elvidge (1899–1985): contributions to the diagnosis of brain tumors and cerebrovascular disease
Authors: Preul Mark C. , Feindel William , Dagi T. Forcht , Stratford Joseph , Bertrand Gilles
Published: June 2009

✓ The contributions of Arthur Elvidge (1899–1985), Wilder Penfield's first neurosurgical recruit, to the development of neurosurgery have been relatively neglected, although his work in brain tumors extended the previous work of Percival Bailey and Harvey Cushing. He published rigorous correlations of clinical and histological information and formulated a revised, modern nosology for neuroepithelial tumors, including a modern histological definition of glioblastoma multiforme. Well ahead of his time, he believed that glioblastoma was not strictly localized and was the first to comment that the tumor frequently showed “satellitosis.” He was the first neurosurgeon in North America to use angiography as a radiographic aid in the diagnosis of cerebrovascular disease. Having studied with Egas Moniz, he was the first to detail the use of angiographic examinations specifically for demonstrating cerebrovascular disorders, believing that it would make possible routine surgery of the intracranial blood vessels. Seeking to visualize all phases of angiography, he was the impetus behind the design of one of the first semi-automatic film changers. Elvidge and Egas Moniz made the first observations on thrombosis of the carotid vessels independently of each other. Elvidge elucidated the significance of embolic stroke and commented on the ischemic sequelae of subarachnoid hemorrhage. Besides his contributions to neurosurgery, he codiscovered the mode of transmission of poliomyelitis. Elvidge's soft-spoken manner, his dry wit and candor, mastery of the understatement, love of exotic travel, and consummate dedication to neurosurgery made him a favorite of patients, neurosurgery residents, nurses, and other hospital staff. His accomplishments and example as teacher and physician have become part of neurosurgery's growing legacy.
Magnetic resonance evaluation of ventrolateral medullary compression in essential hypertension
Authors: Colón Gary P. , Quint Douglas J. , Dickinson Lawrence D. , Brunberg James A. , Jamerson Kenneth A. , Hoff Julian T. , Ross Donald A.
Published: June 2009

Object. The authors designed a blinded prospective study comparing patients with essential hypertension to patients without hypertension in which magnetic resonance (MR) imaging was used to evaluate the role of lateral medullary compression by adjacent vascular structures as a cause of neurogenic hypertension.

Methods. Patients with documented essential hypertension were recruited to undergo thin-slice axial brainstem MR imaging evaluation. Nonhypertensive (control) patients scheduled to undergo MR imaging for other reasons also underwent thin-slice MR imaging to form a basis for comparison. Magnetic resonance images obtained in patients from the hypertensive (30 patients) and the control (45 patients) groups were then compared by four independent reviewers (two neuroradiologists and two neurosurgeons) who were blinded to the patients' diagnosis and hypertensive status. Images were reviewed with regard to left versus right vertebral artery (VA) dominance, compression of the medulla on the left and/or right side, and brainstem rotation. Medullary compression was graded as either vessel contact without associated brainstem deformity or vessel contact with associated brainstem deformity.

Conclusions. There was a tendency toward left VA dominance in the hypertensive group compared with the control group, although a significant difference was shown by only one of the four reviewers. There were no differences in brainstem compression or rotation between the hypertensive and nonhypertensive groups.

These results are contrary to those of recently published studies in which MR imaging and/or MR angiography revealed lateral brainstem vascular compression in hypertensive patients but not in nonhypertensive (control) patients. Reasons for this discrepancy are discussed. On the basis of their own experience and that of others, the authors believe that neurogenic hypertension does exist. However, thin-slice MR imaging may not be a reliable method for detecting neurovascularly induced essential hypertension and the prevalence of neurovascular compression as the source of hypertension may be overestimated when using current imaging techniques.
Neurovascular decompression of the eighth cranial nerve in patients with hemifacial spasm and incidental tinnitus: an alternative way to study tinnitus
Authors: Ryu Hiroshi , Yamamoto Seiji , Sugiyama Kenji , Uemura Kenichi , Nozue Michihiko
Published: June 2009

Object.The authors sought to clarify the clinical characteristics of tinnitus resulting from neurovascular compression (NVC) of the eighth cranial nerve.

Methods.The authors explored the eighth cranial nerve in the cerebellopontine cistern during neurovascular decompression (NVD) of the facial nerve in 10 patients with hemifacial spasm who suffered from incidental tinnitus on the same side. The diagnosis of NVC of the eighth cranial nerve was confirmed in all patients. This condition was found in only seven of 114 patients with hemifacial spasm alone, indicating that NVC of the eighth cranial nerve is one of the causes of tinnitus (p < 0.001, chi-square test). The tinnitus resolved or was markedly improved after NVD of the eighth cranial nerve in eight patients (80%). Both pulsatile and continuous tinnitus responded well to NVD. All patients experienced various degrees of sensorineural hearing disturbance, but other neurotological examinations provided poor diagnostic value.

Conclusions.It is the authors' opinion that sensorineural hearing loss and positive findings on magnetic resonance imaging are the most reliable evidence for the presence of tinnitus caused by NVC of the eighth cranial nerve.
Acquired Chiari I malformation secondary to spontaneous spinal cerebrospinal fluid leakage and chronic intracranial hypotension syndrome in seven cases
Authors: Atkinson John L. D. , Weinshenker Brian G. , Miller Gary M. , Piepgras David G. , Mokri Bahram
Published: June 2009

Object. Spontaneous spinal cerebrospinal fluid (CSF) leakage with development of the intracranial hypotension syndrome and acquired Chiari I malformation due to lumbar spinal CSF diversion procedures have both been well described. However, concomitant presentation of both syndromes has rarely been reported. The object of this paper is to present data in seven cases in which both syndromes were present. Three illustrative cases are reported in detail.

Methods. The authors describe seven symptomatic cases of spontaneous spinal CSF leakage with chronic intracranial hypotension syndrome in which magnetic resonance (MR) images depicted dural enhancement, brain sagging, loss of CSF cisterns, and acquired Chiari I malformation.

Conclusions. This subtype of intracranial hypotension syndrome probably results from chronic spinal drainage of CSF or high-flow CSF shunting and subsequent loss of brain buoyancy that results in brain settling and herniation of hindbrain structures through the foramen magnum. Of 35 cases of spontaneous spinal CSF leakage identified in the authors' practice over the last decade, MR imaging evidence of acquired Chiari I malformation has been shown in seven. Not to be confused with idiopathic Chiari I malformation, ideal therapy requires recognition of the syndrome and treatment directed to the site of the spinal CSF leak.
Comparison of balloon angioplasty and papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage
Authors: Elliott J. Paul , Newell David W. , Lam Derek J. , Eskridge Joseph M. , Douville Colleen M. , Le Roux Peter D. , Lewis David H. , Mayberg Marc R. , Grady M. Sean , Winn H. Richard
Published: June 2009

Object. The purpose of this study was to test the hypothesis that balloon angioplasty is superior to papaverine infusion for the treatment of proximal anterior circulation arterial vasospasm following subarachnoid hemorrhage (SAH). Between 1989 and 1995, 125 vasospastic distal internal carotid artery or proximal middle cerebral artery vessel segments were treated in 52 patients.

Methods. Blood flow velocities of the involved vessels were assessed by using transcranial Doppler (TCD) monitoring in relation to the day of treatment with balloon angioplasty or papaverine infusion. Balloon angioplasty and papaverine infusion cohorts were compared based on mean pre- and posttreatment velocity at 24 and 48 hours using the one-tailed, paired-samples t-test. Balloon angioplasty alone was performed in 101 vessel segments (81%) in 39 patients (75%), whereas papaverine infusion alone was used in 24 vessel segments (19%) in 13 patients (25%). Although repeated treatment after balloon angioplasty was needed in only one vessel segment, repeated treatment following papaverine infusion was required in 10 vessel segments (42%) in six patients because of recurrent vasospasm (p < 0.001). Seven vessel segments (29%) with recurrent spasm following papaverine infusion were treated with balloon angioplasty. Although vessel segments treated with papaverine demonstrated a 20% mean decrease in blood flow velocity (p < 0.009) on posttreatment Day 1, velocities were not significantly lower than pretreatment levels by posttreatment Day 2 (p = 0.133). Balloon angioplasty resulted in a 45% mean decrease in velocity to a normal level following treatment (p < 0.001), a decrease that was sustained.

Conclusions. Balloon angioplasty is superior to papaverine infusion for the permanent treatment of proximal anterior circulation vasospasm following aneurysmal SAH.
Radiosurgery for cavernous malformations
Authors: Karlsson Bengt , Kihlström Lars , Lindquist Christer , Ericson Kaj , Steiner Ladislau
Published: June 2009

Object. The authors examined 22 patients with cavernous malformations (CMs) who had undergone gamma knife radiosurgery (GKRS) to assess the value of this procedure in treating these lesions.

Methods. At the Karolinska Hospital, GKRS was used to treat 23 patients with CMs during the period of 1985 through 1996. One of the patients was lost to follow up and the treatment results of the 22 remaining patients were analyzed. In the first half of the series, the CMs were treated with high doses of radiation (> 15-Gy dose to the periphery); in the second half of the series, lower doses were used.

Nine of the 22 patients suffered a post-GKRS hemorrhage and six developed a radiation-induced complication (two of these patients experienced both). Some time after GKRS was performed, surgical removal of the CM had to be undertaken in four patients because of hemorrhage and in two patients because of radiation-induced complications. Four of the nine patients who experienced no post-GKRS hemorrhage or radiation-induced complication were treated before 1990; recent magnetic resonance imaging revealed a decrease in the size of the CM in three of these individuals and no size change in the other.

The annual post-GKRS hemorrhage rate was 8% in this group. There was a trend in the hemorrhage rate to decrease 4 years postsurgery. There was also a trend for higher radiation doses administered to the periphery of the lesion to result in a lower risk of posttreatment hemorrhage. However, it could not be concluded whether GKRS affects the natural course of a CM. The incidence of radiation-induced complications was approximately seven times higher than that expected if the same number of patients had been treated by GKRS with the same radiation dose distributions for arteriovenous malformations instead of CMs.

Conclusions. The high incidence of radiation-induced complications does not seem to justify the limited protection the treatment may afford in only exceptional cases. A prospective randomized study is needed before the role of radiosurgery in the management of these lesions can be defined. Until such a study has proved differently, a caveat must be raised for the treatment of CM with GKRS.
Platelet-activating factor and edema surrounding meningiomas
Authors: Hirashima Yutaka , Hayashi Nakamasa , Fukuda Osamu , Ito Hideki , Endo Shunro , Takaku Akira
Published: June 2009

Object.The purpose of this study was to evaluate the involvement of platelet-activating factor (PAF) in the formation of edema surrounding meningiomas.

Methods.Volumes of tumor and peritumoral edema were calculated based on three-dimensional reconstructed magnetic resonance images in 31 patients with intracranial meningiomas. The authors measured tumor concentrations of PAF and localized PAF and leukocytes in the tumors by using immunohistochemical studies. A significant positive correlation was found between peritumoral edema and PAF concentration. Both PAF and leukocyte common antigen were localized to the interstitial tissue of the tumor. Edema production was related to the degree of leukocyte infiltration in meningiomas.

Conclusions.It appears that PAF, which may arise from infiltrating leukocytes, is important to the development of peritumoral edema in patients with meningioma.
Adult neuronal ceroid lipofuscinosis with clinical findings consistent with a butterfly glioma
Authors: Hammersen Stefanie , Brock Mario , Cervós-Navarro Jorge
Published: June 2009

✓ The authors report a case of neuronal ceroid lipofuscinosis (Kufs' disease) confirmed by stereotactically obtained brain biopsy findings and initially diagnosed as a butterfly glioma. The presenting symptoms in the 64-year-old patient were mental alterations with progressive dementia, followed by muscular atrophy and myoclonia with distal preponderance. The mild initial disturbances of coordination increased, and the patient developed a markedly ataxic gait. Computerized tomography (CT) scanning and magnetic resonance imaging revealed generalized cerebral atrophy and a bifrontal space-occupying lesion involving the callosum. The original “clearcut” diagnosis of glioblastoma multiforme, based on CT scans, was unexpectedly disproved by examination of stereotactically obtained brain biopsy specimens, which revealed a neuronal ceroid lipofuscinosis (Kufs' disease). To the authors' knowledge, this is the first report of a case presenting with both diffuse brain atrophy and localized accumulation of neuronal lipofuscin, mimicking a mass lesion on radiological studies.
Chordoid meningioma in a child
Authors: Kobata Hitoshi , Kondo Akinori , Iwasaki Koichi , Kusaka Hirofumi , Ito Hidefumi , Sawada Shinji
Published: June 2009

✓ A case of chordoid meningioma occurring in a 15-year-old girl is presented. The patient manifested seizures as the initial symptom and subsequently exhibited subclinical microcytic hypochromic anemia. The tumor, located in the falcotentorial region and associated with diffuse edema, was totally resected. On histological examination of the surgical specimen, the clustering pattern of partly vacuolated cells in the mucoid stroma mimicked chordoma; however, positive staining of individual cells for vimentin and epithelial membrane antigen led to a diagnosis of meningioma. Interestingly, the tumor cells were surrounded by a periodic acid—Schiff— and type IV collagen—positive substance. Electron microscopy demonstrated a strikingly dense and thick basal lamina. The patient's microcytic hypochromic anemia disappeared after the tumor was removed. Both the clinical and pathological features of this case resemble those of chordoid meningioma, a rare meningioma variant.
Preoperative treatment with botulinum toxin to facilitate cervical fusion in dystonic cerebral palsy
Authors: Racette Brad A. , Lauryssen Carl , Perlmutter Joel S.
Published: June 2009

✓ The authors report the use of high-dose botulinum toxin A for muscle relaxation prior to surgery for cervical spine fixation in two patients with dystonic cerebral palsy that included severe cervical dystonia. Both patients had recently developed progressive cervical myelopathy and surgery was planned to halt the insidious progressive weakness. However, marked dystonic posturing of the neck would have compromised their tolerance of halo fixation and subsequently impeded postoperative fusion. Preoperative chemodenervation of selected cervical muscles with injections of high-dose botulinum toxin A eliminated all involuntary neck movements, permitting the patients to tolerate halo fixation and facilitating postoperative spinal fusion. It is concluded that botulinum toxin A can be used safely and effectively in the preoperative management of patients with cervical dystonia and cervical spondylitic myelopathy.
Idiopathic spinal cord herniation
Authors: Miyake Shigeru , Tamaki Norihiko , Nagashima Tatsuya , Kurata Hiromitsu , Eguchi Takahiro , Kimura Hidehiko
Published: June 2009

✓ The authors describe two occurrences of idiopathic spinal cord herniation, an entity that has been reported previously in only 11 cases. The patients described in this report presented in midlife with Brown—Séquard syndrome. Computerized tomography myelography and magnetic resonance (MR) imaging showed ventral displacement of the spinal cord with no apparent dorsal mass. Intraspinal cerebrospinal fluid (CSF) flow studies in which phase-contrast pulse sequence cine MR imaging was used displayed a normal pattern dorsal to the spinal cord. Percutaneous intrathecal endoscopic observation did not disclose dorsal intradural cysts, but ventral adhesions were seen between the spinal cord and the dura. Microsurgical intradural exploration revealed ventrolateral herniation of the cord and a ventral root through a dural defect into an epidural arachnoid cyst. The adhesions were released, the cord was repositioned intradurally, and the dural defect was patched. The patients showed gradual improvement postsurgery, as did most of the patients in the previously reported cases. The CSF flow and endoscopic studies were found to be particularly informative, and dural patching with surgical membrane is recommended.
Rapid termination of intraoperative stimulation-evoked seizures with application of cold Ringer's lactate to the cortex
Authors: Sartorius Carl J. , Berger Mitchel S.
Published: June 2009

✓ One major risk of intraoperative stimulation mapping is the production of stimulation-evoked seizures. Cold Ringer's lactate solution was applied directly to the irritated cortex in 22 patients with stimulation-induced seizures that occurred during intraoperative brain mapping procedures. The irrigation rapidly and reliably terminated these simple partial seizures and eliminated the need for intravenously administered short-acting barbiturates with antiepileptic properties. The authors describe a practical and simple method for controlling stimulation-induced seizure activity during brain mapping procedures.
Ruptured giant intracranial aneurysms. Part I. A study of rebleeding
Authors: Khurana Vini G. , Piepgras David G. , Whisnant Jack P.
Published: June 2009

Object. The present study was conducted to estimate the frequency and timing of rebleeding after initial subarachnoid hemorrhage (SAH) from ruptured giant aneurysms.

Methods. The authors reviewed records of 109 patients who suffered an initial SAH from a giant aneurysm and were treated at the Mayo Clinic between 1973 and 1996. They represented 25% of patients with giant intracranial aneurysms seen at this institution during that 23-year period. Seven of the patients were residents of Rochester, Minnesota, and the rest were referred from other institutions. The aneurysms ranged from 25 to 60 mm in diameter, and 74% were located on arteries of the anterior intracranial circulation. The cumulative frequency of rebleeding at 14 days after admission was 18.4%. Cerebrospinal fluid drainage, cerebral angiography, and delayed aneurysm recurrence were implicated in rebleeding in some of the patients. Rebleeding was not precluded by intraaneurysm thrombosis. Among those who suffered recurrent SAH at the Mayo Clinic, 33% died in the hospital.

Conclusions. Rebleeding from giant aneurysms occurs at a rate comparable to that associated with smaller aneurysms, a finding that should be considered in management strategies.
Compound anterior cranial base fractures: classification using computerized tomography scanning as a basis for selection of patients for dural repair
Authors: Sakas Damianos E. , Beale David J. , Ameen Ameen A. , Whitwell Helen L. , Whittaker Karl W. , Krebs Axel J. , Abbasi Khalid H. , Dias Palithe S.
Published: June 2009

Object. A classification is proposed to organize anterior cranial base fractures systematically according to their location and size. The goal of this study was to determine whether these two variables, irrespective of cerebrospinal fluid (CSF) rhinorrhea, are related to the long-term risk of posttraumatic meningitis and, hence, to standardize decision making concerning surgical repair of associated CSF fistulas.

Methods. With the aid of high-resolution thin-section coronal computerized tomography (CT) scanning, anterior cranial base fractures were classified into the following four major types: I, cribriform; II, frontoethmoidal; III, lateral frontal; and IV, complex (any combination of the other three types). Fractures with a maximum bone displacement that extended farther than 1 cm in any plane were classified as “large” and those less than 1 cm as “small.”

The authors used this classification in a study of 48 patients who were treated by conservative (20 patients) or surgical (28 patients) means. The results showed a gradation of risk: the fracture most likely to develop infection was a large cribriform (Type I) and the least likely was a small lateral frontal (Type III). Statistical analysis showed that the trend for an increased infection rate was related to the cumulative effect of three variables in the following order: 1) prolonged duration of rhinorrhea (analysis of variance [ANOVA], p = 0.017); 2) large size of fracture displacement (ANOVA, p = 0.079); and 3) fracture's proximity to the midline (ANOVA, p = 0.015).

Conclusions. In this series, microsurgical repair was accompanied by a minimum complication rate. Hence, the authors recommend that patients with fractures that combine the aforementioned variables should be considered to have a high long-term risk of infection and their injury should be surgically repaired as soon as the posttraumatic edema has subsided. This applies to the following fractures: large cribriform (Type I) with transient rhinorrhea lasting 5 to 8 days and large frontoethmoidal (Type II) with prolonged rhinorrhea lasting longer than 8 days. Furthermore, the authors conclude that this classification can improve the management of posttraumatic CSF fistulas of the anterior cranial base and may provide insights into the mechanisms underlying their spontaneous repair and susceptibility to meningitis.
Dutch Normal-Pressure Hydrocephalus Study: randomized comparison of low- and medium-pressure shunts
Authors: Boon Agnita J. W. , Tans Joseph T. J. , Delwel Ernst J. , Egeler-Peerdeman Saskia M. , Hanlo Patrick W. , Wurzer Hans A. L. , Avezaat Cees J. J. , de Jong Dirk A. , Gooskens Rob H. J. M. , Hermans Jo
Published: June 2009

Object. The goal of this prospective study was to compare outcome after placement of a low- or medium-pressure shunt in patients with normal-pressure hydrocephalus (NPH).

Methods. Ninety-six patients with NPH were randomized to receive a low-pressure ventriculoperitoneal shunt (LPV; 40 ± 10 mm H2O) or medium high—pressure ventriculoperitoneal shunt (MPV; 100 ± 10 mm H2O). The patients' gait disturbance and dementia were quantified by applying an NPH scale, and their level of disability was evaluated by using the modified Rankin scale (mRS). Patients were examined prior to and 1, 3, 6, 9, and 12 months after surgery. Primary outcome measures were determined by differences between preoperative and last NPH scale scores and mRS grades. The LPV and MPV shunt groups were compared by calculating both the differences between mean improvements and the proportions of patients showing improvement.

Intention-to-treat analysis of mRS grades yielded a mean improvement of 1.27 ± 1.41 for patients with LPV shunts and 0.68 ± 1.58 for patients with MPV shunts (p = 0.06). Improvement was found in 74% of patients with LPV shunts and in 53% of patients with MPV shunts (p = 0.06) and a marked-to-excellent improvement in 45% of patients with LPV shunts and 28% of patients with MPV shunts (p = 0.12). All outcome measures indicated trends in favor of the LPV shunt group, with only the dementia scale reaching significance. After exclusion of serious events and deaths unrelated to NPH, efficacy analysis showed the advantage of LPV shunts to be diminished. Reduction in ventricular size was also significantly greater for patients in the LPV shunt group (p = 0.009). Subdural effusions occurred in 71% of patients with an LPV shunt and in 34% with an MPV shunt; however, their influence on patient outcome was limited.

Conclusions. Outcome was better for patients who had an LPV shunt than for those with an MPV shunt, although most differences were not statistically significant. The authors advise that patients with NPH be treated with an LPV shunt.
Neuroendoscopic approach to intraventricular lesions
Authors: Gaab Michael R. , Schroeder Henry W. S.
Published: June 2009

Object. The purpose of this study was to determine the efficacy of endoscopic treatment in patients with intraventricular tumors.

Methods. A series of 30 patients with endoscopically treated intraventricular lesions is reported. The lesions included seven colloid cysts, six astrocytomas, three subependymomas, two ependymomas, and one each of the following: pineoblastoma, pineocytoma/pineoblastoma (intermediate type), epidermoid cyst, pineal cyst, medulloblastoma, arteriovenous hemangioma, cavernoma, choroid plexus papilloma, pituitary adenoma, craniopharyngioma, melanoma, and germinoma. Total tumor resections, partial resections, biopsies, stent implantations, septostomies, and third ventriculostomies were performed. In two cases (two subependymomas > 2 cm in diameter), piecemeal endoscopic resection was ineffective because of the very firm consistency of the tumors. Therefore the endoscopic procedure was discontinued and the tumors were removed microsurgically. In the remaining cases the procedures were completed as planned. Even in the presence of difficulties such as poor orientation or significant bleeding, there was no need to abandon the endoscopic procedure. A total of 28 strictly endoscopic interventions were performed, in which the average duration was 85 minutes (range 35–170 minutes). All colloid cysts and the epidermoid lesion were completely evacuated and the capsules were widely resected. Total extirpation of solid tumors was achieved in five cases, whereas most astrocytomas were partially resected. The hydrocephalus-related symptoms resolved in all of the 22 patients with cerebrospinal fluid pathway obstruction. There were no endoscopy-related deaths. In two cases, major bleeding occurred and was controlled endoscopically. The authors observed one case of meningitis, one of mutism, two of memory loss attributed to forniceal injury, one of transient trochlear palsy after a biopsy specimen of an aqueductal tumor was obtained, and one of transient confusion after a biopsy specimen of a germinoma was obtained.

Conclusions. In the authors' preliminary experience, the endoscopic approach was found to be safe and effective. In this series, it was possible to achieve relief of noncommunicating hydrocephalus, tumor resections, and even complete tumor removals by using endoscopic techniques. Based on the results, the authors believe that endoscopic techniques should be considered in the treatment of selected intraventricular lesions.
Papillomas and carcinomas of the choroid plexus in children
Authors: Pencalet Philippe , Sainte-Rose Christian , Lellouch-Tubiana Arielle , Kalifa Chantal , Brunelle Francis , Sgouros Spiros , Meyer Philippe , Cinalli Giuseppe , Zerah Michel , Pierre-Kahn Alain , Renier Dominique
Published: June 2009

Object. Choroid plexus tumors are rare intraventricular tumors (1% of all intracranial tumors) that occur mainly in children. The pathophysiological characteristics of associated hydrocephalus, surgical management, and oncological issues related to these tumors remain a matter of debate. To understand more about these tumors, the authors have reviewed their experience with the management of 38 children with choroid plexus tumors.

Methods. There were 25 cases of papilloma and 13 of carcinoma. The mean age of the patients at presentation was 22.5 months, and one-half of the patients were younger than 2 years of age. Hydrocephalus was present in 33 patients and poorly correlated with the size, site, and pathological characteristics of the tumor. In nine children, a ventriculoperitoneal shunt was required after tumor excision, calling into question the notion that cerebrospinal fluid oversecretion is the only cause of hydrocephalus.

Complete excision was achieved in 96% of the cases of papilloma and 61.5% of the cases of carcinoma. These surgical procedures were complicated by the risks of intraoperative hemorrhage, which proved to be fatal in two cases, and postoperative brain collapse, which led to subdural fluid collections requiring subdural shunt placement in six patients. Preoperative embolization was partially successful in four cases and significantly assisted surgery. Preoperative controlled drainage of excessively dilated ventricles and intraoperative gluing of the cortical incision have been used to address the problem of postoperative brain collapse.

Patients with carcinomas were treated postoperatively by chemotherapy alone (seven cases), radiotherapy (one case), or chemotherapy plus radiotherapy (one case). The overall 5-year survival rate was 100% for patients with papillomas and 40% for those with carcinomas.

Conclusions. Total surgical excision is curative in cases of papillomas. For carcinomas, the most effective treatment remains total surgical excision; however, adjuvant treatment in the form of chemotherapy in patients younger than age 3 years, supplemented by radiation therapy in older children, can moderately reduce the risk of recurrence.
Temporal changes in perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin after subarachnoid hemorrhage
Authors: Pluta Ryszard M. , Afshar John K. B. , Boock Robert J. , Oldfield Edward H.
Published: June 2009

Hemoglobin released from hemolysed erythrocytes has been postulated to be responsible for delayed cerebral vasospasm after subarachnoid hemorrhage (SAH). However, the evidence is indirect and the mechanisms of action are unclear. Cerebrovascular tone is regulated by a dynamic balance of relaxing and contracting factors. Loss of the endothelium-derived relaxing factor—nitric oxide in the presence of oxyhemoglobin and overproduction of endothelin-1 stimulated by oxyhemoglobin have been postulated as causes of delayed cerebral vasospasm after SAH.

Object.The authors aimed to investigate this hypothesis using in vivo microdialysis to examine time-dependent changes in the perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin in a primate model of SAH.

Methods.Nine cynomolgus monkeys underwent right-sided frontotemporal craniectomy and placement of a semipermeable microdialysis catheter adjacent to the right middle cerebral artery (MCA). Saline (control group, three animals) or an arterial blood clot (SAH group, six animals) was then placed around the MCA and the catheter. Arteriographically confirmed vasospasm had developed in all animals with SAH but in none of the control animals on Day 7. The dialysate was collected daily for 12 days. Levels of oxyhemoglobin, deoxyhemoglobin, and methemoglobin were measured by means of spectrophotometry.

Perivascular concentrations of oxyhemoglobin, deoxyhemoglobin, and methemoglobin peaked on Day 2 in the control monkeys and could not be detected on Days 5 to 12. Perivascular concentrations of oxyhemoglobin and deoxyhemoglobin peaked on Day 7 in the SAH group, at which time the concentrations in the dialysate were 100-fold higher than in any sample obtained from the control animals. Methemoglobin levels increased only slightly, peaking between Days 7 and 12, at which time the concentration in the dialysate was 10-fold higher than in samples from the control animals.

Conclusions.This study provides in vivo evidence that the concentrations of oxyhemoglobin and deoxyhemoglobin increase in the cerebral subarachnoid perivascular space during the development of delayed cerebral vasospasm. The results support the hypothesis that oxyhemoglobin is involved in the pathogenesis of delayed cerebral vasospasm after SAH and implicate deoxyhemoglobin as a possible vasospastic agent.
Multiple choroid plexus papillomas of the lateral ventricle distinct from villous hypertrophy
Authors: Yoshino Atsuo , Katayama Yoichi , Watanabe Takao , Kurihara Jun , Kimura Shigeyoshi
Published: June 2009

✓ Except for villous hypertrophy of the choroid plexus that may not be true tumors, multiple choroid plexus papillomas are extremely rare. The authors report a case involving multiple choroid plexus papillomas that were distinct from villous hypertrophy. These lesions were localized, one in the atrium of the right lateral ventricle and the other in the inferior horn of the left lateral ventricle. A review of the literature revealed that this case represented the first reported case of true multiple choroid plexus papillomas documented by findings on magnetic resonance imaging.
Primary leptomeningeal astrocytoma
Authors: Ng Ho-keung , Poon Wai-sang
Published: June 2009

✓ Gliomas very rarely arise from the leptomeninges. They can be both solitary and diffuse, and histological examination reveals mostly astrocytic tumors. The authors report a case (the 12th reported in the literature) of a solitary primary glioma of the leptomeninges in a 79-year-old man who presented with repeated seizures. A magnetic resonance image revealed an ill-defined enhancing lesion in the cerebral meninges. Autopsy examination showed a poorly demarcated astrocytoma in the sylvian fissure infiltrating the adjacent subarachnoid space. The literature concerning primary leptomeningeal glioma is reviewed.
Hydrothorax after ventriculoperitoneal shunt placement in a premature infant: an iatrogenic postoperative complication
Authors: Faillace Walter J. , Garrison R. Donald
Published: June 2009

✓ The authors describe the case of a prematurely born infant who developed hydrothorax after ventriculoperitoneal (VP) shunt placement for treatment of posthemorrhagic communicating hydrocephalus. Prior to shunt placement a bout of necrotizing enterocolitis created intense abdominal and peritoneal scarring. The authors postulate that the scarring created poor peritoneal absorption capacity of cerebrospinal fluid (CSF), with preferential flow of CSF from the peritoneal to the pleural cavity. A 99mTc-diethylenetriamine pentaacetic acid radionucleotide study enabled the authors to rule out shunt malfunction, and preferential transdiaphragmatic flow of CSF from the abdomen to the thoracic cavity was demonstrated. The hydrothorax resolved after conversion of the VP shunt to a ventriculoatrial shunt. Respiratory distress after VP shunt placement should be considered an unusual but important sentinel symptom in the differential diagnosis of postoperative shunt complications.
Hemifacial spasm caused by vascular compression of the distal portion of the facial nerve
Authors: Ryu Hiroshi , Yamamoto Seiji , Sugiyama Kenji , Uemura Kenichi , Miyamoto Tsunehiko
Published: June 2009

✓ It is generally accepted that hemifacial spasm (HFS) and trigeminal neuralgia are caused by compression of the facial nerve (seventh cranial nerve) or the trigeminal nerve (fifth cranial nerve) at the nerve's root exit (or entry) zone (REZ); thus, neurosurgeons generally perform neurovascular decompression at the REZ. Neurosurgeons tend to ignore vascular compression at distal portions of the seventh cranial nerve, even when found incidentally while performing neurovascular decompression at the REZ of that nerve, because compression of distal portions of the seventh cranial nerve has not been regarded as a cause of HFS. Recently the authors treated seven cases of HFS in which compression of the distal portion of the seventh cranial nerve produced symptoms. The anterior inferior cerebellar artery (AICA) was the offending vessel in five of these cases. Great care must be taken not to stretch the internal auditory arteries during manipulation of the AICA because these small arteries are quite vulnerable to surgical manipulation and the patient may experience hearing loss postoperatively.

It must be kept in mind that compression of distal portions of the seventh cranial nerve may be responsible for HFS in cases in which neurovascular compression at the REZ is not confirmed intraoperatively and in cases in which neurovascular decompression at the nerve's REZ does not cure HFS. Surgical procedures for decompression of the distal portion of the seventh cranial nerve as well as decompression at the REZ should be performed when a deep vascular groove is noticed at the distal site of compression of the nerve.
Repair of carotid endarterectomy with a collagen-impregnated fabric graft
Authors: Meyer Fredric B. , Windschitl Wanda L.
Published: June 2009

Saphenous vein patch closure of carotid endarterectomies may decrease the risk of acute postoperative occlusion and recurrent stenosis. However, the disadvantages of a vein patch include postoperative rupture and pseudoaneurysm formation.

Object. The authors sought to assess the effectiveness of collagen-impregnated fabric grafts as substitutes for saphenous vein grafts.

Methods. In this report the authors prospectively analyzed 290 consecutive carotid endarterectomies in which a secondary closure was accomplished using a knitted double-velour graft. The 30-day major neurological morbidity and mortality rate was 1.7%. There were no postoperative occlusions or wound hematomas. The rate of recurrent carotid artery stenosis was less than 1%, and the graft site in one patient became infected.

Conclusions. For surgeons who prefer a secondary closure of carotid endarterectomies, the synthetic graft may prove to be a viable alternative to a saphenous vein.
Postimaging brain distortion: magnitude, correlates, and impact on neuronavigation
Authors: Dorward Neil L. , Alberti Olaf , Velani Binti , Gerritsen Frans A. , Harkness William F. J. , Kitchen Neil D. , Thomas David G. T.
Published: June 2009

Object. This prospective study was conducted to quantify brain shifts during open cranial surgery, to determine correlations between these shifts and image characteristics, and to assess the impact of postimaging brain distortion on neuronavigation.

Methods. During 48 operations, movements of the cortex on opening, the deep tumor margin, and the cortex at completion were measured relative to the preoperative image position with the aid of an image-guidance system. Bone surface offset was used to assess system accuracy and correct for registration errors. Preoperative images were examined for the presence of edema and to determine tumor volume, midline shift, and depth of the lesion below the skin surface. Results were analyzed for all cases together and separately for four tumor groups: 13 meningiomas, 18 gliomas, 11 nonglial intraaxial lesions, and six skull base lesions.

For all 48 cases the mean shift of the cortex after dural opening was 4.6 mm, shift of the deep tumor margin was 5.1 mm, and shift of the cortex at completion was 6.7 mm. Each tumor group displayed unique patterns of shift, with significantly greater shift at depth in meningiomas than gliomas (p = 0.007) and significantly less shift in skull base cases than other groups (p = 0.003). Whereas the preoperative image characteristics correlating with shift of the cortex on opening were the presence of edema and depth of the tumor below skin surface, predictors of shift at depth were the presence of edema, the lesion volume, midline shift, and magnitude of shift of the cortex on opening.

Conclusions. This study quantified intraoperative brain distortion, determined the different behavior of tumors in four pathological groups, and identified preoperative predictors of shift with which the reliability of neuronavigation may be estimated.