bluuebunny/crossref_metadata_2025 huggingface dataset:
Radial nerve palsy caused by spontaneously occurring nerve torsion
Authors: Fernandez Eduardo , Di Rienzo Alessandro , Marchese Enrico , Massimi Luca , Lauretti Liverana , Pallini Roberto
Published: May 2009

✓ An 18-year-old man presented with a spontaneously occurring radial nerve palsy that spared the triceps muscle. At surgery, the portion of the radial nerve located at the midarm level had an hourglass-like appearance. Under magnification, an external—internal neurolysis of the narrowed portion of the hourglass-shaped portion revealed nerve torsion. Straightening of the twisted nerve and fixation accomplished using epiperineurium—fascia stitches to avoid a new torsion resulted in complete functional recovery of the radial nerve.
Transcrusal approach to the petroclival region with hearing preservation
Authors: Horgan Michael A. , Delashaw Johnny B. , Schwartz Marc S. , Kellogg Jordi X. , Spektor Sergey , McMenomey Sean O.
Published: May 2009

✓ As a term, the “petrosal approach” to the petroclival region has a variety of meanings. The authors define a common nomenclature based on historical contributions and add new terminology to describe a technique of hearing preservation that allows for greater exposure of the petroclival region. The degree of temporal bone dissection defines five stages of operation. The authors used the second or “transcrusal” stage, in which the posterior and superior semicircular canals are sacrificed while preserving hearing, in six consecutive cases. Use of a common terminology ensures better understanding among surgeons. In the authors' hands, hearing has been successfully preserved in six patients after partial labyrinthectomy.
Peritoneal shunt tube placement performed using an endoscopic threaded imaging port
Authors: Kubo Shigeki , Nakata Hiroyuki , Yoshimine Toshiki
Published: May 2009

✓ The authors used an endoscopic threaded imaging port that originally was developed for laparoscopy to access the peritoneal cavity, and applied this device to the placement of a peritoneal shunt tube in patients suffering from hydrocephalus. Using this system, the peritoneum can be opened quickly under direct vision by using an endoscope through a small skin incision. The peritoneal cavity is secured by replacing the cannula with a polyvinyl chloride (PVC) tube. At the end of surgery, the terminal end of the shunt tube is inserted through the PVC tube, which serves as a guiding catheter. Only one or two skin stitches are needed for closure. This method has proved to be safe, quick, and less invasive than conventional minilaparotomy.
Suboptimum hemicraniectomy as a cause of additional cerebral lesions in patients with malignant infarction of the middle cerebral artery
Authors: Wagner Simone , Schnippering Holger , Aschoff Alfred , Koziol James A. , Schwab Stefan , Steiner Thorsten
Published: May 2009

Object. The goal of this study was to determine the frequency of hemicraniectomy-associated lesions and their potential effect on the risk of mortality in patients suffering from malignant infarction of the middle cerebral artery (MCA).

Methods. The authors evaluated serial computerized tomography scans obtained in 60 patients with complete infarction of the right MCA who were treated using hemicraniectomy. The maximum diameter of the hemicraniectomy was determined and the hemicraniectomy-associated lesions were classified as ischemic lesions or hemorrhages. The category of hemorrhages was composed of parenchymal, subdural, or epidural/subgaleal hematomas.

Parenchymal hemorrhages and infarcts associated with hemicraniectomy occurred with frequency rates of 41.6% and 28.4%, respectively. The occurrence of hemicraniectomy-associated bleeding was related to the size of the hemicraniectomy performed; that is, the smaller the hemicraniectomy, the more often lesions occurred (p < 0.05). Hemicraniectomy-associated bleeding was also related to an increased risk of mortality.

Conclusions. Hemicraniectomy is an effective therapy in patients with malignant infarction of the MCA. However, a hemicraniectomy that is too small in diameter may cause the formation of additional lesions and adversely affect the risk of mortality and the quality of survival. In addition, the size and shape of the edges of the bone defect are important factors relating to its efficacy.
Hypophosphatemia and hypomagnesemia induced by cooling in patients with severe head injury
Authors: Polderman Kees H. , Peerdeman Saskia M. , Girbes Armand R. J.
Published: May 2009

Object. Induced hypothermia in patients with severe head injury may prevent additional brain injury and improve outcome. However, this treatment is associated with severe side effects, including life-threatening cardiac tachyarrhythmias. The authors hypothesized that these arrhythmias might be caused by electrolyte disorders and therefore studied the effects of induced hypothermia on urine production and electrolyte levels in patients with severe head injury.

Methods. Urine production, urine electrolyte excretion, and plasma levels of Mg, phosphate, K, Ca, and Na were measured in 41 patients with severe head injury. Twenty-one patients (Group 1, study group) were treated using induced hypothermia and pentobarbital administration, and 20 patients (Group 2, controls) were treated with pentobarbital administration alone. In Group 1, Mg levels decreased from 0.98 ± 0.15 to 0.58 ± 0.13 mmol/L (mean ± standard deviation; p < 0.01), phosphate levels from 1.09 ± 0.19 to 0.51 ± 0.18 mmol/L (p < 0.01), Ca levels from 2.13 ± 0.25 to 1.94 ± 0.14 mmol/L (p < 0.01), and K levels from 4.2 ± 0.59 to 3.6 ± 0.7 mmol/L (p < 0.01) during the first 6 hours of cooling. Electrolyte levels in the control Group 2 remained unchanged. Electrolyte depletion in Group 1 occurred despite the fact that moderate and, in some cases, substantial doses of electrolyte supplementation were given to many patients, and supplementation doses were often increased during the cooling period. Average urine production increased during the cooling period, from 219 ± 70 to 485 ± 209 ml/hour. When the targeted core temperature of 32°C was reached, urine production returned to levels that approximated precooling levels (241 ± 102 ml/hour). Electrolyte levels rose in response to high-dose supplementation. In the control group, urine production and electrolyte excretion remained unchanged throughout the study period.

Conclusions. Induced hypothermia is associated with severe electrolyte depletion, which is at least partly due to increased urinary excretion through hypothermia-induced polyuria. This may be the mechanism through which induced hypothermia can lead to arrhythmias. When using this promising new treatment in patients with severe head injury, stroke, or postanoxic coma following cardiopulmonary resuscitation, prophylactic electrolyte supplementation should be considered and electrolyte levels should be monitored frequently.
Pediatric cerebral aneurysms
Authors: Proust François , Toussaint Patrick , Garniéri José , Hannequin Didier , Legars Daniel , Houtteville Jean-Pierre , Fréger Pierre
Published: May 2009

Object. The exceptional pediatric aneurysm can be distinguished from its adult counterpart by its location and size; however patient outcomes remain difficult to evaluate based on the published literature.

Methods. Twenty-two children, all consecutively treated in three neurosurgery departments, were included in this study. Each patient's preoperative status was determined according to the Hunt and Hess classification. Routine computerized tomography scanning and angiography were performed in all children on the 10th postoperative day. Each patient's clinical status was evaluated 2 to 10 years postoperatively by applying the Glasgow Outcome Scale (GOS).

Twenty-one children presented with a subarachnoid hemorrhage (SAH) and one child harbored an asymptomatic giant aneurysm. Thirteen patients were in good preoperative grade (Hunt and Hess Grades I to III) and eight in poor preoperative grade (Hunt and Hess Grade IV or V). The symptomatic aneurysms were located on the internal carotid artery bifurcation (36.4%); middle cerebral artery (36.4%), half of which were found on the distal portion; anterior communicating artery (18.2%); and within the vertebrobasilar system (9.1%). A giant aneurysm was observed in 14% of patients. Overall outcome was favorable (GOS Score 5) in 14 children (63.6%) and death occurred in five (22.7%). Causes of unfavorable outcome included the initial SAH in four children, a complication in procedure in three children, and edema in one child.

Conclusions. Pediatric aneurysms have a specific distribution unlike that of aneurysms in the adult population. The incidence of giant aneurysms and outcomes were similar to those in the adult population. The major cause of poor outcome was the initial SAH, in particular, the high proportion of rebleeding possibly due to a delay in diagnosis.
Dynamic cranioplasty for brachycephaly in Apert syndrome: long-term follow-up study
Authors: Guimarães-Ferreira José , Gewalli Fredrik , Sahlin Pelle , Friede Hans , Owman-Moll Py , Olsson Robert , Lauritzen Claes G. K.
Published: May 2009

Object. Brachycephaly is a characteristic feature of Apert syndrome. Traditional techniques of cranioplasty often fail to produce an acceptable morphological outcome in patients with this condition. In 1996 a new surgical procedure called “dynamic cranioplasty for brachycephaly” (DCB) was reported. The purpose of the present study was to analyze perioperative data and morphological long-term results in patients with the cranial vault deformity of Apert syndrome who were treated with DCB.

Methods. Twelve patients have undergone surgery performed using this technique since its introduction in 1991 (mean duration of follow-up review 60.2 months). Eleven patients had bicoronal synostosis and one had a combined bicoronal—bilambdoid synostosis. Perioperative data and long-term evolution of skull shape visualized on serial cephalometric radiographs were analyzed and compared with normative data. Changes in mean skull proportions were evaluated using a two-tailed paired-samples t-test, with differences being considered significant for probability values less than 0.01.

The mean operative blood transfusion was 136% of estimated red cell mass (ERCM) and the mean postoperative transfusion was 48% of ERCM. The mean operative time was 218 minutes. The duration of stay in the intensive care unit averaged 1.7 days and the mean hospital stay was 11.8 days. There were no incidences of mortality and few complications. An improvement in skull shape was achieved in all cases, with a change in the mean cephalic index from a preoperative value of 90 to a postoperative value of 78 (p = 0.000254).

Conclusions. Dynamic cranioplasty for brachycephaly is a safe procedure, yielding high-quality morphological results in the treatment of brachycephaly in patients with Apert syndrome.
Glioblastoma multiforme occurring in a patient treated with gamma knife surgery
Authors: Shamisa Abdalla , Bance Manohar , Nag Sukriti , Tator Charles , Wong Shun , Norén Georg , Guha Abhijit
Published: May 2009

✓ Stereotactic radiosurgery is being increasingly advocated as the primary modality for treatment of vestibular schwannomas (VS). This modality has been shown to arrest tumor growth, with few associated short-term morbidities, and with possibly better hearing and facial nerve preservation rates than microsurgery. Radiation-induced oncogenesis has long been recognized, although stereotactic radiosurgery de novo induction of a secondary tumor has never been clearly described. The authors report on a patient with a VS who did not have neurofibromatosis Type 2 and who underwent gamma knife surgery (GKS). This patient required microsurgical removal of the VS within 8 months because of development of a tumor cyst with associated brainstem compression and progressive hydrocephalus. The operation resulted in clinical stabilization and freedom from tumor recurrence.

Seven and a half years after undergoing GKS, the patient presented with symptoms of raised intracranial pressure. Magnetic resonance imaging demonstrated a new ring-enhancing lesion in the inferior temporal lobe adjacent to the area of radiosurgery, which on craniotomy was confirmed to be a glioblastoma multiforme (GBM). Despite additional conventional external-beam radiation to the temporal lobe, the GBM has progressed. Whereas this first reported case of a GBM within the scatter field of GKS does not conclusively prove a direct causal link, it does fulfill all of Cahan's criteria for radiation-induced neoplasia, and demands increased vigilance for the potential long-term complications of stereotactic radiosurgery, and reporting of any similar cases.
Endovascular trapping of giant serpentine aneurysms by using Guglielmi detachable coils. Successful reduction of mass effect
Authors: Otsuka Goro , Miyachi Shigeru , Handa Takashi , Negoro Makoto , Okamoto Takeshi , Suzuki Osamu , Yoshida Jun
Published: May 2009

✓ Giant serpentine aneurysms (GSAs) are defined as partially thrombosed giant aneurysms with persistent serpentine vascular channels. Surgical management of these rare lesions is difficult because of their large size, complex structure, and unique hemodynamics. The authors report two cases of patients harboring GSAs with mass effect, which were managed effectively with endovascular treatment. The first patient was a 48-year-old man who presented with left homonymous hemianopsia caused by a GSA involving the terminal portion of the right internal carotid artery. The second patient, a 10-year-old boy, presented with tetraparesis from compression of the cervicomedullary junction by a GSA of the right vertebral artery. In each case, after confirming collateral flow by temporarily occluding the proximal artery, the aneurysm was trapped by placement of Guglielmi detachable coils at the sites at which the serpentine channels entered and exited the aneurysm. The midportion of each channel was isolated completely without packing, to maximize resorption of the devascularized mass. Mass effect and clinical symptoms rapidly improved in both cases, with no associated morbidity. We recommend endovascular trapping as a safe and effective therapeutic option for GSAs.
Surgical treatment of posterior fossa tumors via the occipital transtentorial approach: evaluation of operative safety and results in 14 patients with anterosuperior cerebellar tumors
Authors: Shirane Reizo , Kumabe Toshihiro , Yoshida Yasuko , Su Ching-chan , Jokura Hidefumi , Umezawa Kunihiko , Yoshimoto Takashi
Published: May 2009

Object. To determine the safety and usefulness of performing surgery via the occipital transtentorial approach to treat anterosuperior cerebellar tumors, evaluation of 14 patients was performed over a 5-year period.

Methods. The study was performed in 14 patients, aged 6 months to 71 years, who harbored anterosuperior cerebellar tumors of the posterior fossa including four hemangioblastomas, three cerebellar astrocytomas, three medulloblastomas, two metastatic tumors, one recurrent astrocytoma, and one rhabdoid cell tumor. All patients underwent surgical treatment by the same surgical team and via the same surgical approach. Endoscopy combined with neuronavigation was used for large, deep-seated tumors extending to the fourth ventricle. Of the 14 patients, total or gross-total removal was achieved in 12 patients and subtotal removal in two patients. There was no incidence of mortality or morbidity in the 14 patients, and all functional outcomes were good to excellent postoperatively. Postoperative magnetic resonance imaging revealed that none of the patients had suffered brain damage or infarction around the cerebellum, brainstem, or occipital lobe.

Conclusions. Although this study was the first in which a specific examination of the efficacy of the occipital transtentorial approach in patients with anterosuperior cerebellar tumors was undertaken, our findings suggest that this surgical approach is very useful, safe, and accurate for removing the primary tumor and evaluating the surrounding anatomy, as well as for determining operative strategy.
Cranial surgery navigation aided by a compact intraoperative magnetic resonance imager
Authors: Schulder Michael , Liang Danny , Carmel Peter W.
Published: May 2009

Object. In this article the authors report on a novel, compact device for magnetic resonance (MR) imaging that has been developed for use in a standard neurosurgical operating room.

Methods. The device includes a permanent magnet with a field strength of 0.12 tesla. The poles of the magnet are vertically aligned, with a gap of 25 cm. When not in use the magnet is stored in a shielded cage in a corner of the operating room; it is easily moved into position and attaches to a regular operating table. The magnet is raised for imaging when needed and may be lowered to allow surgery to proceed unencumbered. Surgical navigation with optical and/or magnetic probes is incorporated into the system.

Twenty-five patients have undergone removal of intracranial lesions with the aid of this device. Operations included craniotomy for tumor or other lesion in 18 patients and transsphenoidal resection of tumor in seven. The number of scans ranged from two to five per surgery (average 3.4); image quality was excellent in 45%, adequate in 43%, and poor in 12%. In four patients MR imaging revealed additional tumor that was then resected; in five others visual examination of the operative field was inconclusive but complete tumor removal was confirmed on MR imaging. In 21 patients early postoperative diagnostic MR studies corroborated the findings on the final intraoperative MR image.

Using a water-covered phantom, the accuracy of the navigational tools was assessed; 120 data points were measured. The accuracy of the magnetic probe averaged 1.3 mm and 2.1 mm in the coronal and axial planes, respectively; the optical probe accuracy was 2.1 mm and 1.8 mm in those planes.

Conclusions. This device provides high-quality intraoperative imaging and accurate surgical navigation with minimal disruption in a standard neurosurgical operating room.
Patterns of functional magnetic resonance imaging activation in association with structural lesions in the rolandic region: a classification system
Authors: Carpentier Alexandre C. , Constable R. Todd , Schlosser Michael J. , de Lotbinière Alain , Piepmeier Joseph M. , Spencer Dennis D. , Awad Issam A.
Published: May 2009

Object. Functional magnetic resonance (fMR) imaging of the motor cortex is a potentially powerful tool in the preoperative planning of surgical procedures in and around the rolandic region. Little is known about the patterns of fMR imaging activation associated with various pathological lesions in that region or their relation to motor skills before surgical intervention.

Methods. Twenty-two control volunteers and 44 patients whose pathologies included arteriovenous malformations (AVMs; 16 patients), congenital cortical abnormalities (11 patients), and tumors (17 patients) were studied using fMR imaging and a hand motor task paradigm. Activation maps were constructed for each participant, and changes in position or amplitude of the motor activation on the lesion side were compared with the activation pattern obtained in the contralateral hemisphere. A classification scheme of plasticity (Grades 1–6) based on interhemispheric pixel asymmetry and displacement of activation was used to compare maps between patients, and relative to hand motor dexterity and/or weakness.

There was 89.4% interobserver agreement on classification of patterns of fMR imaging activation. Displacement of activation by mass effect was more likely with tumors. Cortical malformations offer a much higher functional reorganization than AVMs or tumors. High-grade plasticity is recruited to compensate for severe motor impairment.

Conclusions. Pattern modification of fMR imaging activation can be systematized in a classification of motor cortex plasticity. This classification has shown good correlation among grading, brain lesions, and motor skills. This proposal of a classification scheme, in addition to facilitating data collection and processing from different institutions, is well suited for comparing risks associated with surgical intervention and patterns of functional recovery in relation to preoperative fMR imaging categorization. Such studies are underway at the authors' institution.
Endothelial proliferation, neoangiogenesis, and potential de novo generation of cerebrovascular malformations
Authors: Sure Ulrich , Butz Nick , Schlegel Jürgen , Siegel Adrian M. , Wakat Jörg P. , Mennel Hans D. , Bien Siegfried , Bertalanffy Helmut
Published: May 2009

Object. To date, both arteriovenous malformations (AVMs) and cavernomas have been considered to be congenital malformations. A recent survey of the literature has shown the potential for de novo generation of both familial and sporadic cavernomas as well as AVMs. Therefore, it was of interest to determine the biological behavior of these lesions in detail.

Methods. The proliferative and angiogenic capacities of the endothelium of 13 cavernomas and 25 AVMs obtained in patients recently treated (1997–1998) at one institution were studied. Immunohistochemical staining for proliferating cell nuclear antigen (PCNA), MIB-1, and vascular endothelial growth factor (VEGF) and its receptor Flk-1 was performed using standard staining procedures. Positive immunostaining of the nuclei of endothelial cells was observed in specimens of both AVMs and cavernomas for PCNA (80% of AVMs and 85% of cavernomas), and Flk-1 (80% of AVMs and 31% of cavernomas). Endothelial expression of VEGF in the 18 incompletely embolized AVMs was found in 72% of cases but only in 28% of the seven cases in which patients did not undergo endovascular treatment; it was found in 38% of cavernomas. Endothelial expression of MIB-1 was found in 12% of AVMs but in no cavernomas.

Conclusions. These results indicate that there is endothelial proliferation as well as neoangiogenesis in cerebral cavernomas and AVMs. The increased level of angiogenesis in only partially obliterated AVMs underscores the need for radical and complete occlusion of cerebral AVMs to avoid recurrences and further risks of morbidity.
Computerized brain-surface voltage topographic mapping for localization of intracranial spikes from electrocorticography
Authors: Otsubo Hiroshi , Shirasawa Atsushi , Chitoku Shiro , Rutka James T. , Wilson Scott B. , Snead O. Carter
Published: May 2009

✓ The purpose of this paper is to describe the use of computerized brain-surface voltage topographic mapping to localize and identify epileptic discharges recorded on electrocorticographic (ECoG) studies in which a subdural grid was used during intracranial video electroencephalographic (IVEEG) monitoring. The authors studied 12 children who underwent surgery for intractable extrahippocampal epilepsy. Cortical surfaces and subdural grid electrodes were photographed during the initial surgery to create an electrode map that could be superimposed onto a picture of the brain surface. Spikes were selected from ictal discharges recorded at the beginning of clinically confirmed seizures and from interictal discharges seen on ECoG studies during IVEEG recording. A computer program was used to calculate the sequential amplitude of the spikes by using squared interpolation, and they were then superimposed onto the electrode map. Interictal discharges and high-amplitude spike complexes at seizure onset were plotted on the map. This mapping procedure depicted the ictal zone in nine patients and the interictal zone in 12, and proved to be an accurate and useful source of information for planning corrective surgery.
Interactive magnetic resonance imaging—guided management of intracranial cystic lesions by using an open magnetic resonance imaging system
Authors: Kollias Spyros S. , Bernays René L.
Published: May 2009

Object. The authors present their experience with neurosurgical procedures requiring real-time imaging feedback such as aspiration of a cystic structure or abscess cavity, decompression of hydrocephalic ventricles, management of arachnoid cysts, and installation of permanent or temporary drainage conduits, in which interactive magnetic resonance (MR) imaging guidance was used to monitor structural alterations associated with the procedure.

Methods. Drainage of eight intraparenchymal brain abscesses in seven patients, decompression of space-occupying cystic or necrotic brain tumors in four patients, and endoscopic management of hydrocephalus associated with arachnoid cysts in three patients were performed using MR imaging—guided frameless stereotaxy in an open-configuration 0.5-tesla superconducting MR imaging system.

Intraoperative MR imaging guidance provided accurate information on the course of the surgical procedure and associated intraoperative changes in tissue position, such as the degree of cyst aspiration, the presence or absence of hemorrhage or induced swelling, and changes associated with decompression of adjacent brain parenchyma and the ventricular system. No clinically significant complications were encountered in any patient. There were no targeting errors, and procedural objectives were accomplished in all cases.

Conclusions. Drainage of brain abscesses, punctures of cystic or necrotic intracranial lesions with subsequent aspiration, and management of hydrocephalus can be performed safely and accurately by monitoring the procedure using real-time MR imaging to obtain immediate feedback on associated dynamic tissue changes.
Mapping of receptive language cortex in bilingual volunteers by using magnetic source imaging
Authors: Simos Panagiotis G. , Castillo Eduardo M. , Fletcher Jack M. , Francis David J. , Maestu Fernando , Breier Joshua I. , Maggio William W. , Papanicolaou Andrew C.
Published: May 2009

Object. There are conflicting claims in the functional imaging literature concerning whether different languages are represented by distinct brain mechanisms in individuals who are proficient in more than one language. This interesting theoretical issue has practical implications when functional imaging methods are used for presurgical language mapping. To address this issue the authors compared the location and extent of receptive language cortex specific to English and Spanish in neurologically intact bilingual volunteers by using magnetic source imaging.

Methods. Areas of the cortex that were specialized for receptive language functions were identified separately for each language in 11 healthy adults who were bilingual in English and Spanish. The authors performed exactly the same procedures used routinely for presurgical receptive language mapping. In each bilingual individual, the receptive language—specific map always encompassed the posterior portion of the superior temporal gyrus. In every case, however, substantial differences in the receptive language maps were also observed for the two languages, regardless of whether each participant's first language was English or Spanish.

Conclusions. Although the reasons for such differences and their ultimate significance in identifying the cerebral mechanisms of language are subject to continuing investigation, their presence is noteworthy and has practical implications for the surgical management of patients with lesions in the temporal and parietal regions of the dominant hemisphere.
Acute ventricular hemorrhage in adults with hydrocephalus managed by corpus callosotomy and fenestration of the septum pellucidum
Authors: Holtzman Robert N. N. , Brust John C. M. , Ainyette Ivan G. , Bowers Paola P. , Tikofsky Ronald S. , Lliguin Hilda M. , Hughes James E. O.
Published: May 2009

✓ Three patients with hypertension-induced basal ganglia or thalamic hemorrhage and ventricular rupture underwent corpus callosotomy and fenestration of the septum pellucidum. A patient with a left thalamic hemorrhage underwent surgery on an emergency basis and made a complete physical recovery, although she retained mild psychomotor deficits. Another patient with a large right basal ganglia hemorrhage who also underwent surgery on an emergency basis retained a spastic left hemiparesis without evident psychomotor deficits. The third patient with a left thalamic and basal ganglia hemorrhage, who was initially awake and then lapsed into stupor days later, underwent surgery, but did not recover consciousness. Hydrocephalus was reversed and effectively controlled in all three patients without having to perform a shunt placement procedure.
A multidisciplinary team approach to skull base chordomas
Authors: Crockard H. Alan , Steel Timothy , Plowman Nicholas , Singh Anoushka , Crossman John , Revesz Tamas , Holton Janice L. , Cheeseman Anthony
Published: May 2009

Object. A multidisciplinary team devised a protocol for long-term care of patients with skull base chordomas. In this study they describe their approach.

Methods. Forty-two patients presented between 1986 and 1998 and were treated by maximum surgical cytoreduction and photon radiation therapy. Tumor volume—doubling time determined on the basis of magnetic resonance imaging, immunostaining, and cell proliferation (Ki67 labeling index [LI]) studies indicated growth rates of individual chordomas. The best outlook was associated with the greatest extent of tumor removal achieved during the first operation. There were no deaths associated with patients who underwent first-time surgery, but there was a 7.1% mortality rate associated with those who underwent subsequent operations. Cerebrospinal fluid leaks, additional cranial nerve palsies, and pharyngeal wound problems were the most difficult management problems encountered after second and subsequent surgeries. The time interval between operations was usually between 2 years and 3 years after the first surgery; very few patients required a second surgery, with a quiescent period in excess of 5 years. Life-table 5- and 10-year survival rates were 77% and 69%, respectively.

Conclusions. The authors believe that this series of skull base chordomas provides new insights into the management of these lesions, particularly with regard to techniques that increase survival times and studies that aid in formulating prognoses.
A multidisciplinary team approach to skull base chondrosarcomas
Authors: Crockard H. Alan , Cheeseman Anthony , Steel Timothy , Revesz Tamas , Holton Janice L. , Plowman Nicholas , Singh Anoushka , Crossman John
Published: May 2009

Object. The authors review their experience with treating skull base chondrosarcomas, which are much rarer than skull base chordomas and differ from them in prognosis and treatment.

Methods. Seventeen patients (12 male and five female patients) with histologically verified chondrosarcomas were followed up prospectively over a 12-year period. The mean age at presentation was 35.9 years. Most patients presented with cranial nerve palsies. Seven had undergone surgery prior to referral to the authors' unit. All underwent maximum surgical cytoreduction by the most direct surgical approach; only the two patients harboring the mesenchymal variant underwent radiotherapy.

Conclusions. One patient died of a pulmonary embolus; the patients harboring mesenchymal chondrosarcomas died at 20 and 36 months, respectively, after treatment. Of the remaining patients, 93% were alive 5 years postsurgery and had a projected 10-year survival rate of 84% (mean survival time 9.3 years). These data emphasize the very slow progression of this tumor compared with skull base chordoma.
Surgery for temporal lobe epilepsy in older patients
Authors: Boling Warren , Andermann Frederick , Reutens David , Dubeau François , Caporicci Laetitia , Olivier André
Published: May 2009

Object. The goal of this study was to evaluate the efficacy of surgery for temporal lobe epilepsy (TLE) in older (≥ 50 years of age) patients.

Methods. The authors conducted a review of all patients 50 years of age or older with TLE surgically treated at the Montreal Neurological Institute and Hospital since 1981 by one surgeon (A.O.). Only patients without a mass lesion were included. Outcome parameters were compared with those of younger individuals with TLE, who were stratified by age at operation.

In patients aged 50 years and older, the onset of complex partial seizures occurred 5 to 53 years (mean 35 years) prior to the time of surgery. Postoperatively, over a mean follow-up period of 64 months, 15 patients (83%) obtained a meaningful improvement, becoming either free from seizures or only experiencing a rare seizure. Most surgery outcomes were similar in both older and younger individuals, except for a trend to more freedom from seizures and increased likelihood of returning to work or usual activities in the younger patients. Note that a patient's long-standing seizure disorder did not negatively affect their ability to achieve freedom from seizures following surgery.

Conclusions. Surgery for TLE appears to be effective for older individuals, comparing favorably with results in younger age groups, and carries a small risk of postoperative complications.
Factors in the natural history of chronic subdural hematomas that influence their postoperative recurrence
Authors: Nakaguchi Hiroshi , Tanishima Takeo , Yoshimasu Norio
Published: May 2009

Object. Factors affecting the postoperative recurrence of chronic subdural hematomas (CSDHs) have not been sufficiently investigated. The authors have attempted to determine features of CSDHs that are associated with a high or low recurrence rate on the basis of the natural history of these lesions and their intracranial extension.

Methods. One hundred six patients (82 men and 24 women) harboring 126 CSDHs who were treated at Tokyo Kosei Nenkin Hospital between January 1989 and April 1998 were studied. Types of CSDHs were classified according to hematoma density and internal architecture, and the intracranial extension of the hematomas were investigated. The postoperative recurrence rate was calculated for each factor.

Based on the internal architecture and density of each hematoma, the CSDHs were classified into four types, including homogeneous, laminar, separated, and trabecular types. The recurrence rate associated with the separated type was high, whereas that associated with the trabecular type was low.

Chronic subdural hematomas are believed to develop initially as the homogeneous type, after which they sometimes progress to the laminar type. A mature CSDH is represented by the separated stage and the hematoma eventually passes through the trabecular stage during absorption.

Based on the intracranial extension of each hematoma, CSDHs were classified into three types, including convexity, cranial base, and interhemispheric types. The recurrence rate of cranial base CSDHs was high and that of convexity CSDHs was low.

Conclusions. Classification of CSDHs according to the internal architecture and intracranial extension may be useful for predicting the risk of postoperative recurrence.
Transsphenoidal surgery and adjuvant gamma knife treatment for growth hormone—secreting pituitary adenoma
Authors: Ikeda Hidetoshi , Jokura Hidefumi , Yoshimoto Takashi
Published: May 2009

Object. The results of combined transsphenoidal surgery and adjuvant gamma knife surgery (GKS) for growth hormone (GH)—secreting adenoma were investigated using biochemical cure criteria for surgery and biological cure criteria for adjuvant GKS.

Methods. Ninety patients (42 male and 48 female patients), ranging from 11 to 75 years of age, underwent transsphenoidal surgery for GH-secreting pituitary adenoma. Preoperative and postoperative GH and insulin-like growth factor-I levels were measured, as was the postoperative GH level after the oral glucose tolerance test. Tumor size, cavernous sinus (CS) invasion, and residual tumor were evaluated using magnetic resonance (MR) imaging. Transsphenoidal microsurgery was performed, followed by adjuvant GKS when there was persistent biochemical evidence of GH hypersecretion with residual tumor detectable in the CS on MR imaging. Patients in whom GKS was contraindicated were treated with conventional radiotherapy or by medical means.

Conclusions. The overall surgical cure rate was 57% based on recently accepted biochemical cure criteria. Patients with no CS invasion achieved a 100% cure rate, whereas patients with CS invasion achieved an 82% cure rate (14 of 17 patients) after adjuvant GKS. The combination of transsphenoidal microsurgery and adjuvant GKS is the optimal therapy for patients with GH-secreting adenoma.
A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein—13 adenoviral gene therapy
Authors: Helm Gregory A. , Li Jin Zhong , Alden Tord D. , Hudson Sarah B. , Beres Elisa J. , Cunningham Mary , Mikkelsen Mark M. , Pittman Debra D. , Kerns Kelvin M. , Kallmes David F.
Published: May 2009

Object. Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector.

Methods. Athymic nude rats were injected with 3.75 × 1010 plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-β-galactosidase in the thigh musculature, and the region was examined using light and electron microscopy at various time points between 2 days and 100 days postinjection. As early as 2 days after injection of Ad-BMP-13, progenitor cells were observed infiltrating between the transduced muscle fibers. These cells subsequently proliferated, differentiated, and secreted large amounts of collagenous extracellular matrix. By 100 days postinjection, the treated tissue displayed the histological and ultrastructural appearance of neotendon/neoligament, which was clearly demarcated from the surrounding muscle. Small foci of bone and fibrocartilage were also seen within the treated tissue. A short-term bromodeoxyuridine study also demonstrated rapid mesenchymal cell proliferation at the Ad-BMP-13 injection site as early as 48 hours postinjection. At all time points, the control AD-β-gal injection sites were found to contain only normal muscle, without evidence of inflammation or mesenchymal cell proliferation.

Conclusions. The results of this study indicate that in the future the use of the BMP-13 gene may have therapeutic utility for the healing of tendon and ligament tears and avulsion injuries.
Transplantation of human fetal brain cells into ischemic lesions of adult gerbil hippocampus
Authors: Barami Kaveh , Hao Hsiao-nan , Lotoczky Gregory A. , Diaz Fernando G. , Lyman William D.
Published: May 2009

Object. The goal of this study was to establish whether transplanted cells derived from fetal human brain can survive in an ischemic lesion.

Methods. Sixteen adult male Mongolian gerbils underwent transient bilateral common carotid artery occlusion. One week later, cell suspensions prepared from fetal human brain were injected using stereotactic guidance into the CA1 region of the hippocampus on one side. On the contralateral side injection of the cell suspension medium only was performed. One week after transplantation, the animals were perfusion fixed and their brains were processed for histological studies as well as expression of neuron and glia-specific antigens. Data from ischemic animals were compared with eight nonischemic gerbils that served as sham-operated controls. Last, the in vivo data were correlated with observations made from matching in vitro cultures of the fetal brain cell suspension.

The in vivo data indicated that transplanted human fetus—derived brain cells survived in ischemic lesions of gerbil hippocampus after 1 week, provided that the host animal underwent adequate immunosuppression and the transplanted cells were not incorporated into the scar caused by the transplantation procedure. Unlike their in vivo counterparts, after 1 week, most cultured fetal brain cells expressed either neuron- or astrocyte-specific antigens.

Conclusions. This work demonstrates that xenotransplanted fetal human brain cells are able to survive in an ischemic lesion in a rodent model. These data might be useful for future neural transplantation studies of treatments for cerebrovascular ischemia in humans.
Concomitant occurrence of macroprolactin, exercise-induced amenorrhea, and a pituitary lesion: a diagnostic pitfall
Authors: Cattaneo Fabio A. , Fahie-Wilson Michael N.
Published: May 2009

✓ The authors report the case of a 37-year-old woman who presented with amenorrhea and an increased level of serum prolactin. Magnetic resonance images of the pituitary revealed a lesion with characteristics consistent with those of a microadenoma. Transsphenoidal exploration was performed, but a prolactinoma was not found. After endocrinological review, the patient's hyperprolactinemia was found to be caused by the presence of macroprolactin and her amenorrhea was due to intense exercise and low body weight. Macroprolactin is an isoform of prolactin that is variably reactive in assays for prolactin, but displays minimum bioactivity in vivo. Patients with macroprolactin are mostly asymptomatic. This phenomenon may cause elevated prolactin values, which the authors view as apparent hyperprolactinemia. The presence of macroprolactin is an underrecognized problem, occurring in as many as 15 to 20% of patients with elevated prolactin values and often leading to unnecessary, expensive diagnostic procedures and inappropriate treatment. The presence of macroprolactin should always be suspected when the patient's clinical history or clinical or radiological data are incompatible with the prolactin value. Physicians dealing with diagnosis and treatment of hyperprolactinemia (general practitioners, gynecologists, neurosurgeons, endocrinologists, and biochemists) should be aware of the potentially misleading nature of macroprolactin.
Recurrence of a neurenteric cyst with malignant transformation in the foramen magnum after total resection
Authors: Sahara Yoshiyuki , Nagasaka Tetsuro , Takayasu Masakazu , Takagi Teruhide , Hata Nobuhiro , Yoshida Jun
Published: May 2009

✓ A 53-year-old man presented with recurrence of a neurenteric cyst with malignant transformation in the foramen magnum 3.5 years after total resection of the original tumor had been reported. For 2 years following the initial surgery, the patient had been in good condition, but then underwent ventriculoperitoneal shunt placement for intracranial hypertension. At the time there was no evidence of recurrence of the tumor on magnetic resonance (MR) images. One and one-half years later, he presented with headache and anorexia. A massive recurrent tumor was identified on MR images. The tumor was severely adhesive to the brainstem, cranial nerves, and vessels, allowing only partial resection. Histological examination of tumor specimens obtained during the first and second craniotomies indicated a malignant change from a typical neurenteric cyst with a one-layer epithelium in the first specimen to an adenocarcinoma with papillary proliferation in the second. The results of various immunohistochemical studies of the first specimen were typical of those of a neurenteric cyst. The second specimen displayed stronger staining of carbohydrate 19-9 and carcinoembryonic antigens than the initial specimen. The percentage of Ki-67 antigen (MIB-1)—positive cells increased from 0% in the first specimen to 6.7% in the second. To the authors' knowledge this is the first case in which malignant transformation has been demonstrated after total resection of a neurenteric cyst in the foramen magnum.
Cerebral hemodynamic impairment after aneurysmal subarachnoid hemorrhage as evaluated using transcranial Doppler ultrasonography: relationship to delayed cerebral ischemia and clinical outcome
Authors: Rätsep Tõnu , Asser Toomas
Published: May 2009

Object. In this study the authors evaluated the relative role of cerebral hemodynamic impairment (HDI) in the pathogenesis of delayed cerebral ischemia and poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH).

Methods. Cerebral hemodynamics were assessed daily with transcranial Doppler (TCD) ultrasonography in 55 consecutive patients with verified SAH. Hemodynamic impairment was defined as blood flow velocity (BFV) values consistent with vasospasm in conjunction with impaired autoregulatory vasodilation as evaluated using the transient hyperemic response tests in the middle cerebral arteries. A total of 1344 TCD examinations were performed, in which the evaluation of HDI was feasible during 80.9% and HDI was registered during 12% of the examinations. It was found that HDI occurred in 60% of patients and was frequently recorded in conjunction with severe vasospasm (p < 0.05) and a rapid increase of BFV values (p < 0.05). Detection of HDI was closely associated with the development of delayed ischemic brain damage after SAH (p < 0.05). Furthermore, because delayed ischemia was never observed in cases in which vasospasm had not led to the development of HDI, its occurrence increased significantly the likelihood of subsequent cerebral ischemia among the patients with vasospasm (p < 0.05). Detection of HDI was independently related to unfavorable clinical outcome according to Glasgow Outcome Scale at 6 months after SAH (p < 0.05).

Conclusions. The results showed that HDI is common after SAH and can be evaluated with TCD ultrasonography in routine clinical practice. Detection of HDI could be useful for identifying patients at high or low risk for delayed ischemic complications and unfavorable clinical outcome after SAH.
A method to estimate urinary electrolyte excretion in patients at risk for developing cerebral salt wasting
Authors: Carlotti Ana P. C. P. , Bohn Desmond , Rutka James T. , Singh Sheila , Berry W. A. David , Sharman Asheer , Cusimano Michael , Halperin Mitchell L.
Published: May 2009

Object. Two major criteria are necessary to diagnose cerebral salt wasting (CSW): a cerebral lesion and a large urinary excretion of Na+ and Cl− at a time when the extracellular fluid (ECF) volume is contracted. Nevertheless, it is difficult for the physician to confirm from bedside observation that a patient has a contracted ECF volume. Hyponatremia, although frequently present, should not be a criterion for a diagnosis of salt wasting. A contracted ECF volume is unlikely if there are positive balances of Na+ and Cl−.

The goal of this study was to assess the accuracy of calculating balances for Na+ plus K+ and of Cl− over 1 to 10 days in an intensive care unit (ICU) setting.

Methods. A prospective comparison of measured and estimated quantities of Na+ plus K+ and of Cl− excreted over 1 to 10 days in 10 children and 12 adults who had recently received a traumatic brain injury or undergone recent neurosurgery. Plasma concentrations of electrolytes were recorded at the beginning and end of the study period. The total volumes infused and excreted and the concentrations of Na+, K+, and Cl− in the infusate were obtained from each patient's ICU chart. The electrolytes in the patients' urine were measured and calculated. Correlations between measured and calculated values for excretions of Cl− and of Na+ plus K+ were excellent.

Conclusions. Mass balances for Na+ plus K+ and for Cl− can be accurately estimated. These data provide information to support or refute a clinical diagnosis of CSW. The danger of relying on balances for these electrolytes measured within a single day to diagnose CSW is illustrated.