bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrospective long-term follow-up analysis in 21 patients with chordomas of various sites treated at a single institution
Authors: Keisch Martin E. , Garcia Delia M. , Shibuya Robert B.
Published: May 2009

✓ Twenty-one patients with chordoma were treated at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, between 1949 and 1986. Thirteen patients had sacrococcygeal tumors, five had clival tumors, two had nasopharyngeal tumors, and one had a lumbar spine tumor. Nine patients were treated with surgery alone, eight patients with subtotal resection and postoperative irradiation, and four patients with radiotherapy alone after biopsy. The 5- and 10-year actuarial survival rates were 74% and 46%, respectively. The 10-year actuarial survival rate was significantly better in patients treated with surgery alone or surgery and irradiation than in those treated with radiotherapy alone (52%, 32%, and 0%, respectively, p = 0.02). Although all patients ultimately suffered a recurrence, those with lumbosacral tumors treated with surgery and irradiation had a longer mean disease-free survival period (6.6 years) than those treated with surgery alone (4.1 years) (p = 0.08). Disease-free survival times of patients with base of the skull tumors was not significantly different between the treatment groups. Irradiation after resection of chordomas appears to increase the time to first relapse in lumbosacral tumors and should be considered after subtotal resection.
The relationship between intelligence and memory following minor or mild closed head injury: greater impairment in memory than intelligence
Authors: Hall Stuart , Bornstein Robert A.
Published: May 2009

✓ This study investigated the performance of patients with minor or mild closed head injury and age/education-matched normal controls on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Wechsler Memory Scale-Revised (WMS-R). The results demonstrated that the control group had significantly higher scores than the patients with closed head injury on all WAIS-R and WMS-R index scores. Further analysis revealed that the patients with closed head injury showed a greater impairment in delayed memory when directly compared to intellectual performance that was not seen in the control group. These results are discussed in relation to findings in patients with more severe closed head injury, the construction of the WAIS-R and the WMS-R, and the performance patterns of the two groups.
Texas Scottish Rite Hospital rod instrumentation for thoracic and lumbar spine trauma
Authors: Benzel Edward C. , Kesterson Lee , Marchand Erich P.
Published: May 2009

✓ The authors present their experience with 28 patients who had incurred unstable thoracic or lumbar spine fractures and who were intraoperatively stabilized with the Texas Scottish Rite Hospital (TSRH) universal instrumentation system. These patients were treated over a 1-year period and reflect an evolving insight into the treatment of thoracic and lumbar spine trauma with universal instrumentation. The TSRH instrumentation system appears equivalent to the more established Cotrel-Dubousset system in most respects.

The construct design of the TSRH system facilitates the safe application of a rigid spinal implant. No cases of instability or pseudoarthrosis were observed during an average follow-up period of 9 months, (minimum 3 months). As the surgical treatment plan evolved, shorter and more compact constructs were increasingly utilized. There were no cases of instrumentation failure, regardless of the number of spinal levels fused or the number of levels instrumented. The value of using short rods when possible is emphasized: they may decrease the incidence of delayed instability and discomfort related to loosening at the hook/bone interface compared to that observed when long-rod systems are used in association with short spine fusions causing a fusion/instrumentation mismatch.
Etiology of cerebral vasospasm in primates
Authors: Macdonald R. Loch , Weir Bryce K. A. , Runzer Tim D. , Grace Michael G. A. , Findlay J. Max , Saito Kenichi , Cook David A. , Mielke Bruce W. , Kanamaru Kenji
Published: May 2009

✓ A primate model was used to determine whether oxyhemoglobin (OxyHb), methemoglobin (MetHb), or bilirubin is likely to be responsible for cerebral vasospasm following subarachnoid hemorrhage (SAH). Forty cynomolgus monkeys were randomly assigned to one of five groups. On Day 0, each animal underwent angiography followed by right craniectomy and placement of an Ommaya reservoir with its catheter adjacent to the right middle cerebral artery (MCA). The animals received intrathecal injections twice a day for 6 days of one of the following solutions: mock cerebrospinal fluid (CSF); OxyHb; MetHb; bilirubin; or supernatant fluid from an incubated mixture of autologous blood and mock CSF. On Day 7, angiography was repeated and the animals were killed. Comparison of angiograms obtained on Day 0 and Day 7 of the experiment showed significant vasospasm of the right MCA and the right anterior cerebral and internal carotid arteries in the animal groups that had received OxyHb or supernatant fluid. There was a smaller reduction in diameter of the same vessels in the bilirubin group (not statistically significant), while no effects were observed in the groups receiving MetHb or mock CSF. Electron microscopy of the right MCA's gave results consistent with the angiographic findings. One monkey in the OxyHb group developed a delayed-onset right MCA infarction. These data suggest that OxyHb is the cause of cerebral vasospasm following SAH.
Effects of hypothermia and hyperthermia on the reactivity of rat intracerebral arterioles in vitro
Authors: Ogura Koichiro , Takayasu Masakazu , Dacey Ralph G.
Published: May 2009

✓ The effects of hypothermia and hyperthermia on the cerebral microcirculation were studied using isolated perfused intracerebral (parenchymal) arterioles obtained from rats. In a temperature-dependent manner, hypothermia (20.0° to 35.0°C) dilated the spontaneous tone developed by the arterioles and also diminished their contractile response to potassium and prostaglandin F2α. In contrast, hyperthermia (40.0° to 45.0°C) induced a biphasic response consisting of initial vasoconstriction and secondary vasodilation. Exposure of the vessels to 45.0°C for 30 minutes irreversibly abolished the spontaneous tone and responsiveness of the arterioles when the temperature of the preparation was returned to 37.5°C. In calcium-free solutions, however, the arteriolar diameter was not affected within a temperature range of 20.0° to 45°C. Furthermore, arterioles that had been in a calcium-free solution during exposure to 45°C temperature recovered their viability at 37.5°C. These results suggest that changes in ambient temperature alter calcium-induced contraction in arteriolar smooth muscle, and that the irreversible effects of hyperthermia on the arterioles are dependent upon extracellular calcium. These studies indicate that alterations in brain temperature may affect the pathogenesis of cerebral ischemia by mechanisms that are in part independent of parenchymal metabolism.
Electrophysiological studies of various graft lengths and lesion lengths in repair of nerve gaps in primates
Authors: Kim Daniel H. , Connolly Seán E. , Gillespie Joseph T. , Voorhies Rand M. , Kline David G.
Published: May 2009

✓ Electrophysiological studies were used to evaluate neurological recovery in 14 rhesus monkeys with different nerve lesion lengths and graft lengths. After exposure of both sciatic nerves in each animal, baseline evoked nerve action potentials, muscle action potentials, and muscle strength values were determined for the posterior tibial nerves. Each nerve was then crushed over a measured distance. Three weeks later, the crushed segments were resected and the defects repaired with sural nerve grafts. In seven animals, 20-mm resection sites were repaired by 4 × 20-mm grafts in one leg and by 4 × 40-mm grafts contralaterally. In the other seven animals, the lengths of resection sites were 10 mm in one leg and 30 mm contralaterally; both nerve defects in these animals were repaired by 4 × 30-mm grafts. Electrophysiological studies were repeated at one interval of either 4, 7, or 12 months after repair. Postoperative electrophysiological values were compared to baseline values and described by the mean values and by percent recovery.

Muscle strength recovery was significantly better in limbs with short lesions. In animals with identical lesion lengths, lesions repaired with shorter grafts (the same length as the defect) did significantly worse than did lesions repaired with longer grafts. This may suggest that any degree of tension at the graft repair site has a deleterious effect on functional nerve regeneration. Nevertheless, it was generally found that nerve lesion length had the greatest negative effect on functional nerve regeneration.
Excision of cavernous angioma with preservation of coexisting venous angioma
Authors: Sasaki Osamu , Tanaka Ryuichi , Koike Tetsuo , Koide Akira , Koizumi Takayuki , Ogawa Hiroshi
Published: May 2009

✓ The case of a patient presenting with dysphasic seizures due to a cavernous angioma coexisting with a venous malformation is reported. The cavernous angioma was resected with preservation of the venous malformation, as confirmed by postoperative studies. The patient was seizure-free following surgery.
Anomalous rib presenting as cervical myelopathy: a previously unreported variant of Klippel-Feil syndrome
Authors: Rock Jack P. , Spickler Eric M.
Published: May 2009

✓ A patient is reported with an anomalous rib that caused compression of the cervical spinal cord and presented with cervical myelopathy. This appears to be the first reported instance of this particular anomaly. The clinicoanatomical aspects of this case are discussed.
Transoral transclival clipping of anterior inferior cerebellar artery aneurysm using new rotating applier
Authors: Crockard H. Alan , Koksel Turgut , Watkin Nigel
Published: May 2009

✓ A large, partly calcified aneurysm buried in the pons and arising from the junction of the basilar artery and the anterior inferior cerebellar artery was successfully occluded using a variangle aneurysm clip with a new rotating pistol-grip applier which allowed transoral access. The authors believe that the new applier, used in association with the current techniques for dural closure, allows for safe transoral surgery for basilar aneurysms.
Stereotactic suboccipital transcerebellar biopsy under local anesthesia using the Cosman-Roberts-Wells frame
Authors: Spiegelmann Roberto , Friedman William A.
Published: May 2009

✓ Previously reported suboccipital transcerebellar stereotactic biopsy methods, performed with the patient in the prone position, have required general endotracheal anesthesia. A technique is described for performing such biopsies with the patient in the lateral decubitus position, under local anesthesia. Phantom planning and routine computerized tomography graphics allow the selection of a safe entry point and intra-axial trajectory to the lesion. The time required for data acquisition and the operative procedure itself compares well with that of more routine biopsy techniques.
The Sterling Hall of Medicine, Yale University School of Medicine
Authors: Collins William F.
Published: May 2009

✓ A brief history of the Sterling Hall of Medicine at Yale University is presented; this building was erected and dedicated in 1925. This event signified the beginning of a new era for the Yale University School of Medicine, making it possible to attract a caliber of faculty that has enabled the School to attain its present place in medical education.
Stereotactic radiosurgery for arteriovenous malformations of the brain
Authors: Lunsford L. Dade , Kondziolka Douglas , Flickinger John C. , Bissonette David J. , Jungreis Charles A. , Maitz Ann H. , Horton Joseph A. , Coffey Robert J.
Published: May 2009

✓ Stereotactic radiosurgery successfully obliterates carefully selected arteriovenous malformations (AVM's) of the brain. In an initial 3-year experience using the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 227 patients with AVM's were treated. Symptoms at presentation included prior hemorrhage in 143 patients (63%), headache in 104 (46%), and seizures in 70 (31%). Neurological deficits were present in 102 patients (45%). Prior surgical resection (resulting in subtotal removal) had been performed in 36 patients (16%). In 47 selected patients (21%), embolization procedures were performed in an attempt to reduce the AVM size prior to radiosurgery. The lesions were classified according to the Spetzler grading system: 64 (28%) were Grade VI (inoperable), 22 (10%) were Grade IV, 90 (40%) were Grade III, 43 (19%) were Grade II, and eight (4%) were Grade I. With the aid of computer imaging-integrated isodose plans for single-treatment irradiation, total coverage of the AVM nidus was possible in 216 patients (95%). The location and volume of the AVM were the most important factors for the selection of radiation dose. Magnetic resonance (MR) imaging was performed at 6-month intervals in 161 patients. Seventeen patients who had MR evidence of complete obliteration underwent angiography within 3 months of imaging: in 14 (82%) complete obliteration was confirmed. Complete angiographic obliteration was confirmed in 37 (80%) of 46 patients at 2 years, the earliest confirmation being 4 months (mean 17 months) after radiosurgery. The 2-year obliteration rates according to volume were: all eight (100%) AVM's less than 1 cu cm; 22 (85%) of 26 AVM's of 1 to 4 cu cm; and seven (58%) of 12 AVM's greater than 4 cu cm. Magnetic resonance imaging revealed postirradiation changes in 38 (24%) of 161 patients at a mean interval of 10.2 months after radiosurgery; only 10 (26%) of those 38 patients were symptomatic. In the entire series, two patients developed permanent new neurological deficits believed to be treatment-related. Two patients died of repeat hemorrhage at 6 and 23 months after treatment during the latency interval prior to obliteration.

Stereotactic radiosurgery is an important method to obliterate AVM's, especially those previously considered inoperable. Success and complication risks are related to the AVM location and the volume treated.
Aneurysms of the intracavernous carotid artery: a multidisciplinary approach to treatment
Authors: Linskey Mark E. , Sekhar Laligam N. , Horton Joseph A. , Hirsch William L. , Yonas Howard
Published: May 2009

✓ Of 43 cavernous sinus aneurysms diagnosed over 6½ years, 23 fulfilled indications for treatment; of these 19 were treated, eight surgically and 11 with interventional radiological techniques. Six small and two giant aneurysms were treated surgically: four were clipped, two were repaired primarily, and two were trapped with placement of a saphenous-vein bypass graft. Seven large and four giant aneurysms were treated with interventional radiological techniques: in five cases the proximal internal carotid artery (ICA) was sacrificed; one aneurysm was trapped with detachable balloons; and five were embolized with preservation of the ICA lumen. The mean follow-up period was 25 months. At follow-up examination, three patients in the surgical group were asymptomatic, two had improved, and three had worsened. Three of these patients had asymptomatic infarctions apparent on computerized tomography (CT) scans. At follow-up examination, four radiologically treated patients were asymptomatic, five had improved, two were unchanged, and none had worsened. One patient had asymptomatic and one minimally symptomatic infarction apparent on CT scans; both lesions were embolic foci after aneurysm embolization with preservation of the ICA.

It is concluded that treatment risk depends more on the adequacy of collateral circulation than on the size of the aneurysm. A multidisciplinary treatment protocol for these aneurysms is described, dividing patients into high-, moderate-, and low-risk groups based on pretreatment evaluation of the risk of temporary or permanent ICA occlusion using a clinical balloon test occlusion coupled with an ICA-occluded stable xenon/CT cerebral blood flow study. Radiological techniques are suggested for most low-risk patients, while direct surgical techniques are proposed for most moderate- and high-risk patients.
Ventricular cerebrospinal fluid eosinophilia in children with ventriculoperitoneal shunts
Authors: Tung Howard , Raffel Corey , McComb J. Gordon
Published: May 2009

✓ To determine the significance of cerebrospinal fluid (CSF) eosinophilia, the charts of 106 patients treated with shunt-related procedures during the calendar year 1985 were reviewed. Sixty-nine patients presented for a shunt revision; their charts were retrospectively reviewed from the time of shunt insertion until January, 1988. The remaining 37 patients had a ventriculoperitoneal shunt inserted during the study period and were subsequently followed to January, 1988. A total of 558 shunt-related procedures were performed on these patients during the study period, with a mean follow-up period of 6.9 years. The infection rate was 3.8%.

Eosinophilia was diagnosed when eosinophils accounted for 8% or more of the total CSF white blood cell count. Ventricular CSF eosinophilia occurred in 36 patients sometime during their clinical course. These 36 patients required a mean of 8.5 shunt revisions, while the remaining patients required a mean of 2.5 revisions (p < 0.001). Shunt infections were also more frequent in patients with eosinophilia (p < 0.01). In no case was peripheral eosinophilia or a parasitic infection present.

This study demonstrates that CSF eosinophilia is common in children with shunts. Children with this laboratory finding will experience more shunt failures. In addition, the new appearance of eosinophilia in the CSF of a patient with a shunt in place suggests the possibility of a shunt infection.
Hyperglycemia and neurological outcome in patients with head injury
Authors: Lam Arthur M. , Winn H. Richard , Cullen Bruce F. , Sundling Nancy
Published: May 2009

✓ To examine the relationship between serum glucose and the outcome of patients suffering from head injury, the authors retrospectively reviewed the clinical course of 169 patients admitted for treatment to Harborview Medical Center (a regional trauma center). All patients underwent craniotomy for evacuation of intracranial hematoma and/or placement of a subarachnoid bolt for intracranial pressure monitoring under general anesthesia. Patients with a Glasgow Coma Scale (GCS) score of 8 or less had significantly higher serum glucose levels than patients with GCS scores of 12 to 15 (mean ± standard error of the mean 192 ± 7 mg/dl vs. 130 ± 8 mg/dl or 10.7 ± 0.4 mmol/liter vs. 7.2 ± 0.4 mmol/liter) (p < 0.0001). Patients who subsequently remained in a vegetative state or died had significantly higher glucose levels both on admission and postoperatively than patients who had good outcome or moderate disability (217 ± 12 mg/dl vs. 167 ± 6 mg/dl or 12.1 ± 0.7 mmol/liter vs. 9.3 ± 0.3 mmol/liter on admission, and 240 ± 16 mg/dl vs. 156 ± 5 mg/dl or 13.3 ± 0.9 mmol/liter vs. 8.9 ± 0.3 mmol/liter postoperatively) (p < 0.0001). Among the more severely injured patients (GCS score ≤ 8), a serum glucose level greater than 200 mg/dl (11.1 mmol/liter) postoperatively is associated with a significantly worse outcome (p < 0.01). The authors conclude that severely head-injured patients frequently develop hyperglycemia and the elevated serum glucose level may aggravate ischemic insults and worsen the neurological outcome in such patients.
Subarachnoid hemorrhage in sickle-cell disease
Authors: Anson John A. , Koshy Mabel , Ferguson Lawrence , Crowell Robert M.
Published: May 2009

✓ The neurological complications of sickle-cell disease include cerebral infarction and intracerebral hemorrhage; subarachnoid hemorrhage (SAH) has been infrequently reported. Among 325 patients with sickle-cell disease followed at the University of Illinois between 1975 and 1989, 11 cases of SAH were identified. Aneurysms were found in 10 of these patients, three of whom had multiple aneurysms. All of the patients had some degree of anemia and nine underwent craniotomy without hematological or neurological complications. From this review it appears that SAH is not uncommon in sickle-cell disease patients and tends to occur at a younger age and with smaller aneurysm size than in the general population. With proper perioperative management, including exchange transfusions to reduce the proportion of hemoglobin S to less than 30%, these patients can undergo angiography and craniotomy without an increased incidence of complications. The techniques used in managing sickle-cell disease patients with SAH are discussed.
Symptomatic subependymoma: a clinicopathological and flow cytometric study
Authors: Lombardi Daniela , Scheithauer Bernd W. , Meyer Fredric B. , Forbes Glenn S. , Shaw Edward G. , Gibney Donna J. , Katzmann Jerry A.
Published: May 2009

✓ Twenty-one intracranial subependymomas were reviewed with regard to presentation, diagnosis, operative findings, and long-term follow-up data. The histopathological features were critically reviewed, and deoxyribunucleic acid analysis was performed by flow cytometry. The patients' mean age was 48.5 years (range 32 to 72 years). In 14 cases the tumor was located in the fourth ventricle, in six within a lateral ventricle, and in one in the third ventricle with extension into the lateral ventricle. Radiographic characteristics included isodensity with minimal enhancement on computerized tomography, frequent dystrophic calcification, and isointensity on T1-weighted or slight hyperintensity on T2-weighted magnetic resonance images. The predominant histological features in all cases were those of classic subependymoma. Nonetheless, pathological examination showed a minor (< 20%) ependymoma component in five cases, significant cytological atypia in seven, mitoses in 11, endothelial prominence in four, and focal hemorrhage-associated necrosis in two. Flow cytometry revealed a diploid pattern in 12 patients, tetraploidy in two, and aneuploidy in one.

Two patients died in the perioperative period. Of the remaining 19, 12 underwent gross total resection (two of whom received postoperative irradiation) and seven underwent subtotal resection (five of whom received irradiation). None of the 12 non-irradiated patients developed tumor progression or died of direct tumor-related causes. Of the seven irradiated patients, follow-up imaging studies demonstrated their tumors to be radioresponsive, particularly with doses of 5000 cGy or greater. Despite the presence of cytological atypia and mitotic activity in the majority of cases, the prognostic effects of such factors as tumor location and the extent of surgical resection outweighed those of the standard histopathological parameters. Routine postoperative irradiation is not recommended, but should be reserved for cases with a symptomatic residual or recurrent subependymomas following surgery.
Treatment of vasospasm with a 480-nm pulsed-dye laser
Authors: Macfarlane Robert , Teramura Atsushi , Owen Christopher J. , Chase Scott , de la Torre Ralph , Gregory Kenton W. , Peterson John W. , Birngruber Reginald , Parrish John A. , Zervas Nicholas T.
Published: May 2009

✓ Laser energy at a wavelength of 480 nm was applied in 1-µsec pulses of 3 to 10 mJ to two models of vasospasm. Rabbit common carotid arteries (CCA's) were constricted chronically by the application of human blood within a silicone sheath. Peak vasospasm developed 24 to 48 hours later, and persisted for up to 6 days. Endovascular laser treatment was delivered to 40 CCA's via a 200-µm diameter silica quartz fiber introduced through the femoral artery. The CCA caliber increased from 60% of the pre-vasospasm control diameter to a minimum post-laser diameter of 83% of control. No instances of laser-induced perforation or of arterial thrombosis were observed for up to 60 days after treatment. Prophylactic laser application to nine normal vessels was able to attenuate the development of vasospasm if blood was applied immediately thereafter (88% vs. 59% of control diameter, p < 0.02), but not if blood was applied 7 days later. Studies in 16 normal CCA's established that there was a considerable margin between the laser energy required to induce dilatation and that which caused perforation, providing that the fiber remained relatively central within the artery. Morphological examination demonstrated focal loss of endothelial cells immediately after laser application, followed approximately 7 days later by the development of areas of intimal hyperplasia. Only minimal changes were observed in the medial or adventitial layers.

In a second study, the basilar artery of seven dogs was constricted chronically by two intracisternal injections of autologous blood 3 days apart. Five dogs received endovascular laser treatment 7 or 10 days after the first injection, when basilar artery diameter was reduced to a mean of 61% and 77% of control, respectively. Immediately following treatment, basilar artery diameter increased to 104% and 102% of resting diameter, respectively. Both untreated and laser-treated arteries were smaller than the control diameter at 30 days (80% and 82%, respectively), but in each group the vasodilatory response to hypercapnia was preserved.

These findings indicate that 1-µsec laser pulses are well tolerated by systemic and cerebral arteries in two different animal models, and suggest that the 480-nm pulsed-dye laser may have an application for the treatment or prophylaxis of cerebral vasospasm.
Successful excision of a juvenile-type spinal arteriovenous malformation following intraoperative embolization
Authors: Touho Hajime , Karasawa Jun , Shishido Hisashi , Yamada Keisuke , Shibamoto Keiji
Published: May 2009

✓ The case of a 57-year-old woman with a 14-year history of progressive paraparesis is presented. Selective spinal angiography revealed a juvenile-type spinal arteriovenous malformation (AVM) with a typical large size and rapid flow. The AVM was located primarily in the retromedullary space at the cervicothoracic junction. The AVM was successfully obliterated by intraoperative embolization using isobutyl-2-cyanoacrylate and surgical excision.
The use of an intraluminal shunt for bypass grafts of the cavernous internal carotid artery
Authors: Hori Tomokatsu , Ikawa Eishi , Takenobu Atsumi , Anno Yuichi , Taniura Seijiro , Watanabe Takashi , Ueda Yoshiyuki
Published: May 2009

✓ The authors describe an indwelling intraluminal shunt for use during graft bypass procedures of the cavernous internal carotid artery. The clinical use of this shunt in a patient with meningioma invading the right cavernous sinus is described. This shunt has also been found applicable during carotid endarterectomy, and should prove to be a useful addition to the neurosurgical armamentarium for skull-base surgery.
An analysis of the natural history of cavernous angiomas
Authors: Del Curling O. , Kelly David L. , Elster Allen D. , Craven Timothy E.
Published: May 2009

✓ The advent of magnetic resonance (MR) imaging has permitted the recognition of many angiographically occult vascular malformations before the development of complications and subsequent surgical removal. This study reviews all patients at one institution who had radiographically identifiable vascular malformations believed to represent cavernous angiomas in order to obtain information on the natural history of this particular lesion. All 8131 craniospinal MR images performed at our medical center from January 1, 1986, to November 30, 1989, were reviewed, and 32 patients were identified with 76 lesions meeting the MR imaging criteria for cavernous angioma. Medical histories, physical examination records, and other data from these patients were then reviewed to determine the frequency of complications. Their mean age at latest follow-up examination (or at surgical removal of the lesion) was 37.6 years (range 16 to 72 years). Sixteen patients (50%) had a history of seizures, seven (22%) had focal neurological deficits, and three (9%) had clinically significant hemorrhage attributable to the cavernous angioma; six patients (19%) were asymptomatic. The estimated risk of hemorrhage for this population is 0.25%/person-year of exposure; the estimated risk of seizure development is 1.51%/person-year. Eight patients underwent surgical procedures, resulting in improved seizure control and/or lessened neurological deficit. Although these lesions are often excised with relative ease and minimal morbidity, the potential risks and benefits of surgery must be weighed carefully before removal of these relatively benign malformations.
Stereotactic ventrolateralis thalamotomy for medically refractory tremor in post-levodopa era Parkinson's disease patients
Authors: Fox Mark W. , Ahlskog J. Eric , Kelly Patrick J.
Published: May 2009

✓ Thirty-six patients with Parkinson's disease and medically refractory tremor underwent stereotactic ventrolateralis thalamotomy at the Mayo Clinic between 1984 and 1989. All patients had been or were being treated with carbidopa/levodopa but with unsatisfactory tremor control. Modern stereotactic techniques, including microelectrode recording, were used to treat 36 patients, of whom 31 (86%) had complete abolition of tremor and three patients (5%) had significant improvement. Tremor recurred in two patients within 3 months of surgery; however, the remaining patients suffered no recurrence of tremor during follow-up periods ranging from 14 to 68 months (mean 33 months). Persistent complications (arm dyspraxia, dysarthria, dysphasia, or abulia) were noted in five patients but were a source of disability in only two. It is concluded that thalamotomy in carefully selected patients is a beneficial operation for the control of medically refractory parkinsonian resting tremor.
Cerebral vasospasm evaluated by transcranial Doppler ultrasonography at different intracranial pressures
Authors: Klingelhöfer Jürgen , Sander Dirk , Holzgraefe Manfred , Bischoff Christian , Conrad Bastian
Published: May 2009

✓ The present study evaluates the interdependence of clinical stage, cerebral vasospasm, intracranial pressure (ICP), and transcranial Doppler ultrasonographic parameters. The mean flow velocity of blood in the middle cerebral artery and the index of cerebral circulatory resistance as a measure of the peripheral vascular flow resistance were determined in 76 patients with spontaneous subarachnoid hemorrhage. The ICP was measured using an epidural transducer in 41 patients. There was no case in which both high ICP and a high mean flow velocity were observed simultaneously. The investigations led to the following conclusions. 1) In patients with a resistance index of less than 0.5, changes in the mean flow velocity seem to reflect sufficiently the actual severity and time course of vasospasm. 2) During the time course of vasospasm, an increase in the resistance index above values of 0.6 with a simultaneously decreased mean flow velocity indicates a rise in ICP rather than a reduction in vasospasm. 3) With a pronounced increase in ICP, evaluation of the severity and time course of vasospasm by transcranial Doppler ultrasonography based solely upon the mean flow velocity can lead to false-negative results.
Elevated intracranial pressure from cerebral venous obstruction by Masson's vegetant intravascular hemangioendothelioma
Authors: Wen Dennis Y. , Hardten David R. , Wirtschafter Jonathan D. , Sung Joo Ho , Haines Stephen J.
Published: May 2009

✓ The case is described of a 15-year-old girl with papilledema and visual obscurations caused by a rare lesion, Masson's vegetant intravascular hemangioendothelioma, within the venous sinus at the torcular herophili. This lesion impeded cranial venous outflow, leading to intracranial hypertension.
Compulsive polydipsia following meningioma resection: an epileptic phenomenon?
Authors: Rabinowicz Adrian L. , Weiss Martin H. , DeGiorgio Christopher M.
Published: May 2009

✓ The authors report the case of an individual who developed compulsive polydipsia following resection of a left sphenoidal ridge meningioma. The episodic, stereotyped nature of his symptoms, response to treatment, and electroencephalographic and magnetic resonance imaging findings are all highly consistent with temporal lobe-onset epilepsy. The pathophysiology of this underrecognized phenomenon is discussed.
The image of the “brain surgeon” in American culture: the influence of Harvey Cushing
Authors: Greenblatt Samuel H.
Published: May 2009

✓ In contemporary American culture, the term “brain surgeon” conjures up the image of an intensely singleminded professional, who deals with terribly complex matters of life and death. These descriptors find their personification in Harvey Cushing, because they are derived directly from him. This hypothesis was tested by a complete search of the New York Times Index and the Reader's Guide to Periodical Literature for the years 1919 to 1942. All entries for Harvey Cushing were reviewed in the original sources.

In the New York Times, Cushing's first significant exposure was in response to his winning a Pulitzer Prize in 1925. Major editorial coverage began in 1934, and was especially prominent with the publication of From a Surgeon's Journal in 1936. The process of lionizing Cushing by creating an overdrawn caricature reached its apotheosis in Time magazine in 1939. The Time article was actually a report of Cushing's 70th birthday party. It expounded all of the descriptors that are now associated with “brain surgeon.”

Thus, it was Cushing's literary skills that initially brought him recognition from editors who were arbiters of public opinion. This attention seems to have been the conduit to his mythologization by the larger public. Although unnamed, it is really Cushing's image that still persists as the prototypical “brain surgeon” in the collective American consciousness.
Chiari's description of cerebellar ectopy (1891)
Authors: Koehler P. J.
Published: May 2009

✓ One hundred years ago, Chiari published his first paper on cerebellar ectopy. The contribution of his paper and those of Cleland (1883) and Arnold (1894) to the development of the knowledge of craniocervical abnormalities is discussed. Some early contributions (those of Tulp and Ollivier d'Angers) to the subject of neural-tube defects were also studied and it is concluded that Chiari's name should be connected with the different types of cerebellar ectopy.
Combined endovascular embolization and surgery in the management of cerebral arteriovenous malformations: experience with 101 cases
Authors: Viñuela Fernando , Dion Jacques E. , Duckwiler Gary , Martin Neil A. , Lylyk Pedro , Fox Allan , Pelz David , Drake Charles G. , Girvin John J. , Debrun Gerard
Published: May 2009

✓ The authors describe their experience with 101 cerebral arteriovenous malformations (AVM's) treated by endovascular embolization followed by surgical removal. Fifty-three patients presented with intracranial hemorrhage and 35 had seizures. Based on the classification of Spetzler and Martin, two AVM's were Grade I, 13 were Grade II, 26 were Grade III, 43 were Grade IV, and 17 were Grade V, Fifty-six AVM's were in the right hemisphere, 28 were in the left hemisphere, 12 were in the corpus callosum, and five involved the cerebellum. In 50 cases, presurgical obliteration of 50% to 75% of the AVM nidus was achieved by embolization, and in 31 cases this percentage increased to between 75% and 90%. In 97 (96%) patients, complete surgical removal of the AVM was obtained.

Morbidity resulting from preoperative endovascular embolization was classified as mild in 3.9% of the cases, moderate in 6.9%, and severe in 1.98%. The death rate related to embolization was 0.9%. The immediate postsurgical morbidity was classified as mild in 5.9% of the cases, moderate in 10.8%, and severe in 5.9%. The overall long-term morbidity was mild in 5.9% of the cases, moderate in 6.9%, and severe in 1.98%. Two patients (1.98%) died due to intractable intraoperative hemorrhage and two (1.98%) as a result of postsurgical pulmonary complications.
Stereotactic third ventriculostomy in patients with nontumoral adolescent/adult onset aqueductal stenosis and symptomatic hydrocephalus
Authors: Kelly Patrick J.
Published: May 2009

✓ Sixteen consecutive patients with obstructive hydrocephalus due to nontumoral aqueductal stenosis of adolescent or adult onset underwent computerized tomography-guided stereotactic third ventriculostomy. Computer-assisted angiographic target-point cross-registration was used in surgical planning to reduce morbidity. The procedure was used as primary treatment in five previously unshunted patients and in 11 patients who had previously received shunts and who presented when their shunts became obstructed (five patients), became infected (five patients), or required multiple revisions (one patient). At the time of third ventriculostomy, shunt hardware was removed in patients with infected shunts and the distal element of the shunt was ligated in all patients with obstructed shunts except one, who later required repeat third ventriculostomy; the distal shunt was ligated at that time. Follow-up data (range 1 to 5 years, mean 3½ years, after surgery) showed that only one of the 16 patients had undergone a shunting procedure after the third ventriculostomy. The other 15 patients are asymptomatic and shunt-independent. In previously shunt-dependent patients, the peripheral subarachnoid space and cerebrospinal fluid absorption mechanism remained patent in spite of shunts placed earlier. Therefore, in patients with obstructive hydrocephalus due to aqueductal stenosis of adolescent or adult onset, stereotactic third ventriculostomy should be seriously considered as primary surgical management in previously unshunted patients and in shunt-dependent patients with obstructed or infected shunts.
Morphological study of clinically nonsecreting pituitary adenomas in patients under 40 years of age
Authors: Yamada Shozo , Kovacs Kalman , Horvath Eva , Aiba Tadashi
Published: May 2009

✓ Clinically nonsecreting pituitary adenomas removed at surgery from 69 patients under 40 years of age were studied by histological, immunocytochemical, and transmission electron microscopic examination. By morphological analysis. 19 tumors were found to be null-cell adenomas. 17 silent gonadotroph adenomas, 14 silent subtype 3 adenomas of unknown cellular origin, 13 silent subtype 1 or subtype 2 corticotroph adenomas, three oncocytomas, and three silent thyrotroph adenomas. These results indicate that the incidence of null-cell adenomas and oncocytomas, which are known to be the most common types of nonsecreting pituitary adenomas in patients over 40 years of age, is relatively low in younger patients. This trend is even more obvious in patients younger than 30 years of age.

It can be concluded that clinically nonsecreting pituitary adenomas represent a heterogeneous group morphologically, and that the incidence of the different tumor types varies depending on the patient's age. These findings underline the importance of careful morphological studies. It is proposed that, in order for the correct morphological diagnosis to be made, tumors removed surgically from patients with clinically nonsecreting pituitary adenomas (especially younger patients) should be investigated not only by histological means but also by immunocytochemical and electron microscopic examination. The information obtained from such analysis may be useful in assessing prognosis and deciding on the appropriate treatment.
The effect of age on outcome following traumatic brain injury in rats
Authors: Hamm Robert J. , Jenkins Larry W. , Lyeth Bruce G. , White-Gbadebo Daphne M. , Hayes Ronald L.
Published: May 2009

✓ Age of the patient is one of the most important predictors of outcome following human traumatic brain injury. This study employs the fluid-percussion model to investigate the effects of aging on outcome following traumatic brain injury in rats. The results revealed that there was an age-associated increase in mortality rate following both low (1.7 to 1.8 atm) and moderate (2.00 to 2.25 atm) levels of traumatic brain injury. Age-related changes in systemic physiological, neurological, and histopathological indexes of brain injury were also examined following a low level of traumatic brain injury. Traumatic brain injury produced equivalent acute hypertension and increased plasma glucose levels in both young adult and aging rats. Injury produced an acute increase in heart rate in the young adult rat group, while the heart rate decreased in the aged rats. At low levels of brain injury, no significant gross histopathological alterations were produced in either age group. Neurological outcome was assessed by measuring the duration of suppression of a number of nonpostural and postural reflexes and more complex somatomotor functions (righting, escape, head support). Except for head support, there was a significant age-related increase in the duration of the suppression of these reflexes following brain injury. These data demonstrate that aging is associated with an increased mortality rate and greater acute neurological deficits following traumatic brain injury. These data also demonstrate the usefulness of the fluid-percussion model for studying the mechanisms responsible for the age-related increase in vulnerability to brain injury.
Expression and modulation of major histocompatibility antigens on murine primary brain tumor in vitro
Authors: Akbasak Aytac , Oldfield Edward H. , Saris Stephen C.
Published: May 2009

✓ Lysis of tumor cells by activated cytotoxic lymphocytes requires their recognition of antigens associated with major histocompatibility complex molecules. The authors studied the constitutive expression of Class I and Class II major histocompatibility complex antigens on mouse brain-tumor cells and the capacity of different cytokines and cytokine combinations to alter this expression in vitro. Cells from the murine glioma 26 (GL26), glioma 261 (GL261), and ependymoblastoma A (EpA) cell lines were established in monolayer culture and treated for 48 hours with either alpha interferon, gamma interferon, tumor necrosis factor alpha, tumor necrosis factor alpha plus gamma interferon, or interleukin-2. They were then analyzed by flow cytometry for baseline and cytokine-altered major histocompatibility complex expression.

All cell lines had a similar constitutive major histocompatibility complex pattern with low Class I antigen expression and no detectable Class II antigen expression. Alpha interferon substantially induced and up-regulated Class I antigen expression, but had no effect on Class II antigen expression. Gamma interferon also stimulated up-regulation of Class I antigen expression, generally doubling the anti-Class I antigen fluorescence of treated cells. Its effect on Class II antigen expression was more extensive. In the GL26 and GL261 cell lines, the expression of Class II antigen determinants increased to 12 × and 14 × control values and as many as 75% of cells that had no detectable constitutive expression of Class II antigen expressed this antigen after priming with gamma interferon. The addition of tumor necrosis factor alpha to gamma interferon further increased Class II antigen expression on EpA tumor cells only. Interleukin-2 and tumor necrosis factor alpha alone had no effect on Class I or Class II antigen expression of any cell lines.

It is concluded that Class I and Class II antigen expression in mouse glioma cell lines is induced and enhanced after treatment with certain cytokines in vitro. Use of these cell lines to create in situ primary brain tumors in C57BL/6 mice should provide an excellent animal system to study major histocompatibility complex modulation in brain tumor cells and to examine the potential impact of major histocompatibility complex up-regulation on the response of brain tumors to immunotherapy.
Hypersensitivity of rat glioma sublines with acquired ACNU resistance to L-asparaginase
Authors: Saito Yuji , Nakada Yosihiro , Hotta Takuhiro , Mikami Takasi , Kurisu Kaoru , Kiya Katuzou , Kawamoto Keiichi , Uozumi Tohru
Published: May 2009

✓ Cell lines resistant to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) show a high degree of collateral sensitivity to L-asparaginase. The mechanism for this phenomenon was investigated by comparing the nutritional requirements and asparagine synthetase activity of the resistant sublines to those of parent cells. Nine ACNU-resistant sublines were isolated from rat glioma 9L cells after incubation with various concentrations of ACNU in Ham's F-12 medium. The 9L cells grew independently of asparagine, developing well in asparagine-deficient Dulbecco's modified Eagle's medium. In contrast, the growth rates of all nine ACNU-resistant sublines decreased under the same conditions and required the addition of 10−4 M asparagine for maximum growth. Asparagine synthetase activity in the ACNU-resistant cells was much lower than in the 9L cells, suggesting that the requirement for asparagine in the resistant sublines was due to reduced activity of this enzyme. A growth-inhibition assay showed that the ACNU-resistant sublines were more sensitive to L-asparaginase than 9L cells by up to 2 × 105-fold. These results suggest that L-asparaginase therapy has the potential to become a new approach for treating acquired ACNU resistance.
Surgically verified variations in the A1 segment of the anterior cerebral artery
Authors: Mäurer Johannes , Mäurer Elisabeth , Perneczky Axel
Published: May 2009

✓ Two patients with rare variations of the A1 segment of the anterior cerebral artery are presented. One patient had a perforation of the optic tract by an abnormal course of the A1 segment, and the other harbored an aneurysm of the A1 segment running below the optic nerve. The authors present a summary of A1 segment variations described in the literature.
Metastatic juvenile pilocytic astrocytoma
Authors: Obana William G. , Cogen Philip H. , Davis Richard L. , Edwards Michael S. B.
Published: May 2009

✓ The authors report the case of a metastatic juvenile pilocytic astrocytoma of the hypothalamic region in a 10-year-old boy. Eight years after craniotomy and radiation therapy, the tumor spread via cerebrospinal fluid pathways to the left cerebellar tonsil and the lumbosacral region. Histological evaluation of both the original hypothalamic and the new lumbosacral masses showed features of a slow-growing juvenile pilocytic astrocytoma with no evidence of malignant transformation. The clinical implications and possible mechanisms of metastatic spread are discussed.
Anomalous subarcuate loop
Authors: Goel Atul , Sekhar Laligam N.
Published: May 2009

✓ An anomalous subarcuate loop of the anterior inferior cerebellar artery is described in which the artery is adherent to or penetrates the posterior fossa dura in the subarcuate fossa. When encountered during acoustic neurilemoma surgery, the artery should be carefully mobilized along with a sleeve of dura to prevent its injury.
Novel Oversampling Technique for Improving Signal-to-Quantization Noise Ratio on Accelerometer-Based Smart Jerk Sensors in CNC Applications
Authors: Rangel-Magdaleno Jose  J. , Romero-Troncoso Rene  J. , Osornio-Rios Roque  A. , Cabal-Yepez Eduardo
Published: May 2009

Jerk monitoring, defined as the first derivative of acceleration, has become a major issue in computerized numeric controlled (CNC) machines. Several works highlight the necessity of measuring jerk in a reliable way for improving production processes. Nowadays, the computation of jerk is done by finite differences of the acceleration signal, computed at the Nyquist rate, which leads to low signal-to-quantization noise ratio (SQNR) during the estimation. The novelty of this work is the development of a smart sensor for jerk monitoring from a standard accelerometer, which has improved SQNR. The proposal is based on oversampling techniques that give a better estimation of jerk than that produced by a Nyquist-rate differentiator. Simulations and experimental results are presented to show the overall methodology performance.