bluuebunny/crossref_metadata_2025 huggingface dataset:
Is polar spongioblastoma a tumor entity?
Authors: Schiffer Davide , Cravioto Humberto , Giordana Maria Teresa , Migheli Antonio , Pezzulo Tiziana , Vigliani Maria Claudia
Published: May 2009

✓ The distribution of cells in a parallel fashion with palisades of nuclei is common in neuroepithelial tumors. The authors have selected 16 such tumors from their series for study, as examples of different neuroepithelial oncotypes containing palisades of nuclei: three ependymomas, three hemispheric pilocytic astrocytomas, three oligodendrogliomas, three medulloblastomas, three cerebellar astrocytomas, and one central neuroblastoma. In two additional tumors, affecting a 12-year-old girl and a 51-year-old woman, this feature was present in the entire surgical specimen and the diagnosis was consistent with a polar spongioblastoma. This diagnosis applies in the literature to rare tumors of childhood and adolescence, both malignant and with embryonal features. In one specimen, a clear ependymomatous feature was found in a remote area of the tumor and in the other there were ultrastructural characteristics of neuroblastoma. Nuclear palisades can be found as local architectural features in many neuroepithelial tumors. The rare tumors diagnosed as polar spongioblastoma, according to published criteria, correspond to ependymomas and neuroblastomas. Polar spongioblastoma does not exist as a tumor entity.
Role of histocompatibility antigen gene and proto-oncogene expressions in intracerebral tumorigenicity of mouse neuroblastoma
Authors: Yamasaki Toshiki , Klein George , Ljunggren Hans-Gustaf , Kärre Klas , Moritake Kouzo , Paine Jonathan T. , Kikuchi Haruhiko
Published: May 2009

✓ The role of N-myc, c-src, and major histocompatibility complex (MHC, H-2 in the mouse) class I antigen gene expressions in dimethyl sulfoxide (DMSO)-induced differentiation and intracerebral tumorigenicity was examined using a mouse MNB85 neuroblastoma cell line. A fluorescence-activated cell sorter disclosed cell-surface MHC enhancement by DMSO, causing an increase in cytotoxic T-lymphocyte sensitivity. Southern blot analysis verified a single copy of the proto-oncogenes and MHC deoxyribonucleic acids in both untreated and DMSO-treated MNB85 cells. Northern blot analysis indicated that DMSO treatment induced a decrease in N-myc and an increase in c-src and MHC messenger ribonucleic acids. Nuclear run-off transcription assay revealed down-regulation of N-myc at a posttranscriptional level, contrasted with primary up-regulation of c-src at a transcriptional level. Immunoprecipitation after treatment with enzyme endo-beta-N-acetyl-glycoseamidase H proved that the terminal glycosylation of MHC heavy-chain gene products normally occurs in the Golgi apparatus of MNB85 cells. Intracerebral tumorigenicity assay showed that cells highly MHC-expressed by DMSO were less tumorigenic than untreated cells in association with DMSO-augmented cytotoxic T-lymphocyte susceptibility. These results suggest that proto-oncogenes may be linked to cellular differentiation, while cell-surface MHC gene expression influences intracerebral immunosurveillance.
LINAC radiosurgery: an animal model
Authors: Spiegelmann Roberto , Friedman William A. , Bova Frank J. , Theele Daniel P. , Mickle J. Parker
Published: May 2009

✓ Fifteen cats were irradiated with an animal LINAC (linear accelerator) radiosurgery device. After 6 months, they were studied with gadolinium-enhanced magnetic resonance (MR) imaging, gross pathology after Evans blue perfusion, and histopathology. The lesion size was relatively constant in the cats receiving a dose of 7500, 10,000, 12,500, or 15,000 cGy to the 84% isodose line of a 1-cm collimator. The composition of the lesion correlated with dose: the lower-dose lesions were found histologically to contain areas of edema, demyelination, reactive gliosis, and vascular proliferation; the higher-dose lesions contained increasing amounts of hemorrhage and coagulative necrosis. The borders of the lesions were sharply demarcated from surrounding normal brain. Gadolinium-enhanced MR studies correlated well with areas of blood-brain barrier breakdown, as confirmed by areas of Evans blue staining. This model could serve as the basis for further studies of the biological effects of LINAC radiosurgery.
The radiobiology of human acoustic schwannoma xenografts after stereotactic radiosurgery evaluated in the subrenal capsule of athymic mice
Authors: Linskey Mark E. , Martinez A. Julio , Kondziolka Douglas , Flickinger John C. , Maitz Ann H. , Whiteside Theresa , Lunsford L. Dade
Published: May 2009

✓ An experimental model with xenograft transplantation into the subrenal capsule of athymic (nude) mice was used to evaluate the early response of human acoustic schwannomas to stereotactic radiosurgery. After xenograft placement, 45 mice underwent radiosurgery with single doses of 10, 20, or 40 Gy using a 201-source 60Co gamma unit (4-mm collimator, single isocenter, 80% isodose line). The 45 radiosurgery-treated xenografts were compared with 15 untreated xenografts and 15 xenografts in mice that underwent “sham radiosurgery.” All five study groups were matched for the following pretreatment variables: patient of origin, animal weight, average xenograft diameter, and percentage of xenograft surface vascularity. Immediately prior to sacrifice of the mice all xenografts were evaluated in situ to determine the average tumor diameter, tumor volume, and percentage of surface vascularity. Mice were sacrificed 2 weeks, 1 month, or 3 months after radiosurgery. Blinded histological review was performed by an independent neuropathologist.

Tumor volume was reduced 33.6% after 2 weeks (p = 0.023) and 45% after 3 months (p = 0.018) in the 40-Gy radiosurgery group. Tumor volume was reduced by 46.2% after 1 month (p = 0.0002) and 35.2% after 3 months (p = 0.032) in the 20-Gy radiosurgery group. An average volume reduction of 16.4% was observed after 3 months (p = 0.17) in the 10-Gy radiosurgery group. At 3 months after surgery, tumor surface vascularity was reduced by an average of 19.7% (p = 0.043) in the 40-Gy radiosurgery group and 5.8% (p = 0.12) in the 20-Gy radiosurgery group and was unchanged in the 10-Gy radiosurgery group and both control groups. Histological examination demonstrated a higher incidence of hemosiderin deposits (p = 0.026) and vascular mural hyalinization (p = 0.032) in radiosurgery xenografts versus control.

The subrenal capsule xenograft in nude mice was an excellent model for studying the in vivo radiobiology of acoustic schwannomas after radiosurgery. Both cellular and vascular effects could be assessed serially in situ and the model was stable even 4 months after transplantation. Additional studies investigating radiobiology over periods better approximating the time course of clinical neuroimaging changes (6 to 12 months) are warranted.
Halifax interlaminar clamp for posterior cervical fusion: a long-term follow-up review
Authors: Aldrich E. Francois , Weber Peter B. , Crow Wayne N.
Published: May 2009

✓ Fifty consecutive patients requiring posterior cervical fusion for various pathologies were treated with Halifax interlaminar clamps for internal spinal fixation. Fusion involved the C1–2 level in 17 cases, the C1–3 level in one, and the lower cervical area (C2–7) in 32. No patient was lost to follow-up review, which varied from 6 to 40 months (average 21 months). Fusion failed in five patients, three at the C1–2 level, one at the C1–3 level, and one at the C2–3 level. Screw loosening was the cause of failure in four patients, and in one the arch of C-1 fractured. No other complications occurred. Because of the lack of complications, avoidance of the hazards of sublaminar instrumentation, and an excellent fusion rate, this technique is highly recommended for posterior cervical fusion in the lower cervical spine. Atlantoaxial arthrodesis was achieved in only 14 (82%) of 17 patients, however, which might be due to the higher mobility at this multiaxial level. Improved results in this region may be possible by using a new modified interlaminar clamp, by performing adequate bone fusions, and by postoperative external halo immobilization in high-risk patients.
Clinical and electroneurographic evaluation of sensory/motor-differentiated nerve repair in the hand
Authors: Deutinger Maria , Girsch Werner , Burggasser Georg , Windisch Alfred , Mayr Norbert , Freilinger Gerhard
Published: May 2009

✓ In 17 patients acetylcholinesterase activity was used to differentiate between sensory and motor fascicles in median and ulnar nerve repair of the hand. Eleven patients received follow-up evaluation 1 to 11 years after surgery, and at that time clinical and electroneurographic examinations were performed to evaluate the techniques. Clinical examination showed that four patients had regained on average 71.9% of hand function after median nerve repair, one patient had regained 83.6% of hand function after ulnar nerve repair, four patients had regained on average 53.3% of hand function after median and ulnar nerve repair, and two patients had regained on average 43.5% of hand function after median and partial ulnar nerve repair. The contribution of the ulnar nerve to reinnervation of the thenar muscles was 68.5%, whereas the median nerve did not contribute to reinnervation of the hypothenar muscles. Distal latencies for the median nerve showed a delay of 36% of the upper limit of normal value, and those for the ulnar nerve revealed a delay of 21.5%. This study demonstrated that sensory/motor-differentiated nerve repair of the median and ulnar nerves is possible and can be proven electroneurographically.
The surgical treatment of painful traumatic neuromas
Authors: Burchiel Kim J. , Johans Timothy J. , Ochoa Jose
Published: May 2009

✓ Pain following suspected nerve injury was comprehensively evaluated with detailed examination including history', neurological evaluation, electrodiagnostic studies, quantitative sensory testing, thermography, anesthetic agents, and sympathetic nerve blocks. Forty-two surgically treated patients fell into four discrete groups: Group 1 patients had distal sensory neuromas treated by excision of the neuroma and reimplantation of the proximal nerve into muscle or bone marrow; Group 2 patients had suspected distal sensory neuromas in which the involved nerve was sectioned proximal to the injury site and reimplanted; Group 3 patients had proximal in-continuity neuromas of major sensorimotor nerves treated by external neurolysis; and Group 4 patients had proximal major sensorimotor nerve injuries at points of anatomical entrapment treated by external neurolysis and transposition, if possible. Patient follow-up monitoring from 2 to 32 months (average 11 months) was possible in 40 (95%) of 42 patients. Surgical success was defined as 50% or greater improvement in pain using the Visual Analog Scale or pain relief subjectively rated as either good or excellent, without postoperative narcotic usage. Overall, 16 (40%) of 40 patients met those criteria. Success rates varied as follows: 44% in 18 Group 1 patients, 40% in 10 Group 2 patients, 0% in five Group 3 patients, and 57% in seven Group 4 patients. Twelve (30%) of 40 patients were employed both pre- and postoperatively.

It is concluded that: 1) neuroma excision, neurectomy, and nerve release for injury-related pain of peripheral nerve origin yield substantial subjective improvement in a minority of patients; 2) external neurolysis of proximal mixed nerves is ineffective in relieving pain; 3) surgically proving the existence of a neuroma with confirmed excision may be preferable; 4) traumatic neuroma pain is only partly due to a peripheral source; 5) demographic and neurological variables do not predict success; 6) the presence of a discrete nerve syndrome and mechanical hyperalgesia modestly predict pain relief; 7) ongoing litigation is the strongest predictor of failure; and 8) change in work status is not a likely outcome.
Referral bias in aneurysmal subarachnoid hemorrhage
Authors: Whisnant Jack P. , Sacco Sara E. , O'Fallon W. Michael , Fode Nicolee C. , Sundt Thoralf M.
Published: May 2009

✓ The objective of this study was to assess the effect of referral bias on survival in patients with subarachnoid hemorrhage (SAH). The characteristics of 49 patients with aneurysmal SAH from a single community were compared with those of 328 patients referred from outside the community, all treated in the same medical care setting. In addition, referral patients who received surgery were compared by differential survival analysis with those still awaiting surgery at Days 1 to 3, Days 4 to 10, and Days 11 to 15.

There was a dramatic difference in the 30-day survival rate between referral patients (83%) and community patients (59%), but most of the difference had occurred by the 2nd day after SAH. In the referral patients, the variables present at first medical attention that were found to have an independent effect on survival were clinical grade, presence of coma, number of days from SAH to referral, diastolic blood pressure, and patient age. There was a higher survival rate at 1 year for patients who were surgically treated compared with those awaiting surgery for each of the three time periods. Patients who underwent early surgical treatment had a 1-year survival rate almost identical to that of patients with late surgery.

Referral patients had a better early survival rate than did community patients because the referral group did not include patients who died and some who were in poor clinical condition before the opportunity for referral. The differential survival analysis described provides a new method for estimating survival for treated and untreated patients with SAH.
Optical imaging of bipolar cortical stimulation
Authors: Haglund Michael M. , Ojemann George A. , Blasdel Gary G.
Published: May 2009

✓ In order to better understand the degree of cortical activation that occurs during bipolar surface stimulation, the authors stimulated monkey visual cortex while monitoring the degree of activation with optical imaging. Optical imaging of intrinsic signals in monkey visual cortex during visual stimulation resulted in functional maps of ocular dominance and orientation selectivity. After functional maps of ocular dominance and orientation preference were obtained, bipolar surface stimulation was applied to activate just the cortical areas around the bipolar electrodes. Graded responses to changes in the stimulation intensity and duration were found. These findings demonstrate the reliability of bipolar cortical surface stimulation in localizing functional regions of cortex. The area of activation, at least in the region around the bipolar stimulating electrodes, did not appear to activate nearby ocular dominance columns or orientation patches. Intraoperative bipolar surface stimulation continues to be a consistently reliable technique for localizing rolandic cortex and essential language sites.
Acute obstructive hydrocephalus caused by a migrating intraventricular calculus
Authors: Tan En-Chow , Takagi Takuji , Matsuura Seiji , Mizuno Shiro
Published: May 2009

✓ A 10-year-old boy presented with acute obstructive hydrocephalus caused by the impaction of a calculus on the cerebral aqueduct. The calculus migrated from the third ventricle to the fourth ventricle after ventricular drainage and right ventriculoperitoneal shunt placement had been performed. The nature and origin of the calculus could not be determined, although its release from the choroid plexus in the lateral ventricle is highly possible.
Encapsulated intracerebral hematomas: a defined entity
Authors: Roda José M. , Carceller Fernando , Pérez-Higueras Antonio , Morales Carmen
Published: May 2009

✓ Encapsulated intracerebral hematoma is an interesting and not widely appreciated entity. It can be defined as an intraparenchymal hematoma found in normotensive patients, usually caused by histologically confirmed vascular malformations, characterized by a gradual clinical onset, and presenting a well-defined capsule at operation. One case is presented and 25 previously reported cases are reviewed, all reflecting the above-mentioned characteristics. The hematomas reviewed here occurred in relatively young patients with a mean age of 35 years and a clear male predominance (19 males, seven females).

A ring of contrast enhancement around a lesion of variable density, usually with mass effect and perifocal edema, is the most relevant feature on computerized tomography. Findings on magnetic resonance images are described for the first time in the reported case. A vascular malformation was the most frequent cause found on histological examination (12 of the 26 total cases). No proven cause was found in the remaining 14 cases, although a small vascular malformation, destroyed or thrombosed after rupturing and bleeding, is the most likely etiology in these patients.
Improved transdural exposure and temporary occlusion of the petrous internal carotid artery for cavernous sinus surgery
Authors: Wascher Thomas M. , Spetzler Robert F. , Zabramski Joseph M.
Published: May 2009

✓ Safe surgery for vascular and neoplastic lesions involving the cavernous sinus requires adequate proximal control of the cavernous internal carotid artery (ICA). Classically, control of the cavernous ICA has necessitated dissection and isolation of the cervical vessels. The authors describe an alternative method for obtaining vascular control via transdural exposure of the petrous ICA and the use of the Fogarty balloon embolectomy catheter inserted extra-arterially into the carotid canal to provide temporary occlusion. This method is particularly well suited for proximal ICA occlusion during short-segment petrous-to-paraclinoid ICA bypass procedures as it eliminates the need for a temporary proximal ICA aneurysm clip and increases the available working space for completion of the anastomosis.
Pulsatile increases in aneurysm size determined by cine phase-contrast MR angiography
Authors: Meyer Fredric B. , Huston John , Riederer Stephen S.
Published: May 2009

✓ The internal flow dynamics were assessed in 16 cerebral aneurysms by cine phase-contrast magnetic resonance (MR) angiography. Six of the aneurysms were associated with subarachnoid hemorrhage and 10 were unruptured. The ruptured aneurysms demonstrated a 51% ± 10% increase in volume between systole and diastole, while the increase in volume of the unruptured aneurysms was 17.6% ± 8.9% (p < 0.005). The ruptured aneurysms demonstrated an approximate 1.0- to 1.5-mm increase in diameter in at least one dimension during systole. There was no relationship between aneurysm size and volumetric increases. These findings suggest that cine phase-contrast MR angiography can detect structural weakness in the aneurysmal wall. Imaging techniques that can evaluate aneurysmal wall dynamics may be useful in therapeutic planning.
Computer-derived density spectral array in detection of mild analog electroencephalographic ischemic pattern changes during carotid endarterectomy
Authors: Kearse Lee A. , Martin Dean , McPeck Kathleen , Lopez-Bresnahan Maria
Published: May 2009

✓ The purpose of this prospective study was twofold: 1) to determine the sensitivity and specificity of computer-derived density spectral array in detecting analog electroencephalographic (EEG) ischemic pattern changes during carotid artery cross-clamping in patients undergoing carotid endarterectomy; and 2) to assess the ability of density spectral array to identify such changes in comparison with the degree and type of change seen in the analog EEG ischemic pattern. Sixteen channels of anteroposterior bipolar and two to four channels of referential electroencephalography with four channels of density spectral array were monitored simultaneously during carotid endarterectomy in 103 patients under general anesthesia. Two “observers” interpreted the density spectral array and the analog electroencephalograms, one during and immediately after the operations and the other 6 months after completion of all surgery. Analyses were conducted to establish both the number of patients with analog EEG ischemic changes and the number of ischemia events during carotid artery cross-clamping. Observer A indicated that the density spectral array identified analog EEG ischemic changes in 21 of 29 patients, for a sensitivity of 72% (specificity 99%), whereas Observer B's results showed that the density spectral array identified analog EEG ischemic changes in 16 of 27 patients, for a sensitivity of 59% (specificity 96%). Density spectral array detection of analog EEG ischemic changes based on severity classifications were 61% and 18% in the mild group, 70% and 71% in the moderate group, and 95% in the severe group, indicating a relationship between density spectral array sensitivity and severity of analog EEG ischemic change, with p = 0.02 and p = 0.004 for the two observers. The kappa statistics for observer reproducibility were highly significant, with k = 0.95 for analog EEG ischemic changes and 0.85 for density spectral array changes. It is concluded that density spectral array does not reliably detect mild analog EEG pattern changes of cerebral ischemia and is not a reliable substitute for 16-channel analog EEG monitoring of cerebral ischemia during carotid endarterectomy.
A study of safe entry zones via the floor of the fourth ventricle for brain-stem lesions
Authors: Kyoshima Kazuhiko , Kobayashi Shigeaki , Gibo Hirohiko , Kuroyanagi Takayuki
Published: May 2009

✓ Direct surgery for intra-axial lesions of the brain stem is considered a hazardous procedure, and morbidity of varying degrees cannot be avoided even with partial removal or biopsy. The main causes of morbidity relate to direct damage during removal of the lesion, selection of an entry route into the brain stem, and the direction of brain stem retraction. The authors examined the possibility of making a medullary incision and retracting the brain stem, taking into account the symptomatology and surgical anatomy, and found two safe entry zones into the brain stem through a suboccipital approach via the floor of the fourth ventricle. These safe entry zones are areas where important neural structures are less prominent. One is the “suprafacial triangle,” which is bordered medially by the medial longitudinal fascicle, caudally by the facial nerve (which runs in the brainstem parenchyma), and laterally by the cerebellar peduncle. The second is the “infrafacial triangle,” which is bordered medially by the medial longitudinal fascicle, caudally by the striae medullares, and laterally by the facial nerve. In order to minimize the retraction-related damage to important brain-stem structures, the brain stem should be retracted either laterally or rostrally in the suprafacial triangle approach and only laterally in the infrafacial triangle approach.

Three localized intra-axial brain-stem lesions were treated surgically via the safe entry zones using the suprafacial approach in two and the infrafacial approach in one. The cases are described and the approaches delineated. Both approaches are indicated for focal intra-axial lesions located unilaterally and dorsal to the medial lemniscus in the lower midbrain to the pons. Magnetic resonance imaging is useful in selecting these approaches, and intraoperative ultrasonography is helpful to confirm the exact location of a lesion before a medullary incision is made. These approaches can also be used as routes for aspiration of brain-stem hemorrhage as well as for tumor biopsy.
Biopsy-proven isolated sarcoid meningitis
Authors: Mayer Stephan A. , Yim Gregory K. , Onesti Stephen T. , Lynch Timothy , Faust Phyllis L. , Marder Karen
Published: May 2009

✓ Neurosarcoidosis without systemic involvement is rare and difficult to diagnose. The case of a 27-year-old man with a 6-week history of headache, mental status changes, and polyradiculopathy attributable to hypoglycorrheic lymphocytic meningitis is presented. Extensive testing for occult systemic sarcoidosis was negative. The presence of noncaseating granulomatous inflammation was established by open brain biopsy, and the patient improved clinically with oral steroid therapy. In individuals with undiagnosed chronic meningitis, brain biopsy may be necessary to rule out isolated neurosarcoidosis.
Selective endovascular treatment of 71 intracranial aneurysms with platinum coils
Authors: Casasco Alfredo E. , Aymard Armand , Gobin Y. Pierre , Houdart Emmanuel , Rogopoulos André , George Bernard , Hodes Jonathan E. , Cophignon Jean , Merland Jean Jacques
Published: May 2009

✓ Seventy-one intracranial aneurysms were treated by endovascular techniques, with the placement of minicoils inside the aneurysmal sac. Most aneurysms were manifest by hemorrhage (67 cases), and 43 of these were treated within the first 3 days after presentation. At the 1-year follow-up examination, the outcome was scored as good in 84.5% of cases, but the morbidity and mortality rates were 4.2% and 11.3%, respectively. Twenty-nine aneurysms in the anterior circulation and 42 in the posterior circulation were treated. In this series, 23 patients were classified as Hunt and Hess neurological Grade I, 27 as Grade II, 12 as Grade III, nine as Grade IV, and none as Grade V. Thirty-three aneurysms were less than 10 mm in diameter, 28 were 10 to 25 mm, and 10 were larger than 25 mm. The preliminary results from this study appear to justify the emergency treatment of aneurysms by this approach. Aneurysms in the posterior circulation are particularly well suited for this type of surgery.
Arteriovenous fistulas of the brain and the spinal cord
Authors: Tomlinson Francis H. , Rüfenacht Daniel A. , Sundt Thoralf M. , Nichols Douglas A. , Fode Nicolee C.
Published: May 2009

✓ Arteriovenous (AV) fistulas of cerebral and spinal arteries are characterized angiographically by an immediate AV transition without a capillary bed or “nidus” as occurs in AV malformations (AVM's). The clinical presentation, morphology, radiology, and treatment of 12 patients with cerebral AV fistulas and of 12 patients with spinal AV fistulas are reviewed. In the patients with cerebral lesions, headache and seizure disorders were the most common presentations followed by subarachnoid hemorrhage, cardiac failure, progressive neurological dysfunction, and incidental detection on prenatal ultrasound study. In patients with spinal AV fistulas, weakness and sensory disturbance in the lower extremities were the most frequent clinical presentations followed by back pain, disturbances of micturition, and grand mal seizure. The etiology of the symptom complex produced by AV fistulas in each of these locations differed, with venous hypertension being important in spinal cord lesions.

Of the patients with cerebral lesions, nine had a single AV fistula, one had two fistulas, and two had multiple fistulas. An AVM was observed in five patients with fistulas (two large, three small). Nine patients exhibited extramedullary AV fistulas of the spine, of whom eight had a single fistula and one had three fistulas; three patients had intramedullary spinal AV fistulas. An arterial aneurysm was found in association with two fistulas, one cerebral and one spinal. Venous ectasias or varices, frequently exhibiting mural calcification, were observed to be prominent in all AV fistulas involving cerebral arteries and in two involving spinal arteries. The location and size of the venous complexes reflected the diameter of the fistula. In addition to conventional imaging techniques (cerebral angiography, computerized tomography, and magnetic resonance (MR) imaging), MR angiography was a helpful adjunct in the evaluation of fistulas. Treatment strategies employed for AV fistulas in both locations included open surgical and endovascular procedures, frequently used in combination. A satisfactory outcome was observed in all patients.
Meningiomas induced by high-dose cranial irradiation
Authors: Mack Ellen E. , Wilson Charles B.
Published: May 2009

✓ Although meningiomas are known to be induced by low doses of cranial irradiation, such as those given to treat tinea capitis, little experience has been reported on the induction of meningiomas by high-dose cranial irradiation. The authors describe a series of 10 patients with meningiomas and a previous history of high-dose radiation therapy, usually given for a primary brain tumor. Of the 10 patients, eight were female, three had multiple meningiomas, and the majority had other stigmata of previous radiation therapy. Eight meningiomas were examined pathologically and one-half were classified as either aggressive or atypical, or were noted to have a high bromodeoxyuridine labeling index. The average time from radiation therapy to diagnosis of a meningioma was 24 years (range 5 to 40 years), a shorter interval than that previously reported for meningiomas induced by lower doses of irradiation. Within this series, patient age at irradiation was significantly correlated with tumor latency; individuals who were younger at the time of radiation therapy had a shorter time to meningioma formation. The latency of meningioma formation is therefore influenced by both the radiation dose and the age of the patient at irradiation.
Moyamoya phenomenon after radiation for optic glioma
Authors: Kestle John R. W. , Hoffman Harold J. , Mock Antonio R.
Published: May 2009

✓ The role of radiotherapy in the management of patients with optic pathway glioma is controversial. In a series of patients with optic pathway glioma treated at The Hospital for Sick Children in Toronto, five children were encountered who developed moyamoya phenomenon after radiotherapy. A retrospective review of the medical records was undertaken in order to assess the relationship between optic pathway glioma, neurofibromatosis type 1 (NF1), radiation therapy, and moyamoya disease.

Forty-seven patients with optic pathway glioma were operated on at The Hospital for Sick Children between 1971 and 1990. The moyamoya phenomenon did not occur in any of the 19 patients not receiving radiotherapy. Among the 28 patients who received radiotherapy, five developed moyamoya disease (two of 23 without NF1 and three of five with NF1). There was a statistically significant relationship between radiotherapy and moyamoya disease when the analysis was stratified according to the presence of NF1 (Mantel-Haensel chi-squared test 15.23, p < 0.01). The high incidence of moyamoya disease (three of five cases, or 60%) in patients with NF1 who have undergone radiotherapy suggests a synergistic relationship that should be considered when formulating a treatment plan for NF1 patients with optic pathway glioma.
Results of surgical treatment for growth hormone-secreting pituitary adenomas
Authors: Davis Dudley H. , Laws Edward R. , Ilstrup Duane M. , Speed James K. , Caruso Michela , Shaw Edward G. , Abboud Charles F. , Scheithauer Bernd W. , Root Lynn M. , Schleck Cathy
Published: May 2009

✓ The results of surgical therapy for acromegaly were reviewed in a series of 175 patients treated between 1972 and 1983. Patients with prior surgery or radiation therapy were excluded from the study. Postoperative radiation therapy was given to 54 patients. The criterion of achieving a postoperative basal or glucose-suppressed growth hormone level of 2 ng/ml or less was used to indicate remission. Utilizing the most recently available growth hormone determinations, 90 (51.7%) of 174 patients were in remission. The actuarial probability of remission at 1 and 5 years after surgery was 48.8% and 62.7%, respectively. Tumor size and the preoperative basal growth hormone level were correlated with outcome. Surgical excision of a pituitary adenoma is the most effective therapy currently available for acromegaly.
Reversible dementia due to macroprolactinoma
Authors: Brisman Michael H. , Fetell Michael R. , Post Kalmon D.
Published: May 2009

✓ Subfrontal tumors are an infrequent cause of dementia. Most of those that do cause dementia are meningiomas, and the symptoms may recede when the tumor is resected. A patient with a huge prolactinoma who came to medical attention because of dementia is described. The tumor shrank dramatically after bromocriptine therapy and the patient's mental status returned to normal.
Occipital-axis posterior wiring and fusion for atlantoaxial dislocation associated with occipitalization of the atlas
Authors: Jain Vijendra K. , Takayasu Masakazu , Singh Satnam , Chharbra Devendra K. , Sugita Kenichiro
Published: May 2009

✓ The authors present their technique of occipital-axis posterior wiring and fusion for atlantoaxial dislocation associated with an occipitalized atlas. The technique consists of drilling a 3 × 1-cm horizontal groove in the occipital bone 1 cm posterior to the foramen magnum and building up a bony bridge along the posterior margin of the foramen magnum. This bony bridge is referred to as an “artificial atlas.” Conventional wiring and fusion is performed between the artificial atlas and the C-2 lamina, interposing a strut bone graft. Since the compression force on tightening the wire is vertical, a very high degree of stability for the occipital-C-2 complex is achieved, facilitating early mobilization without postoperative redislocation.
Deliberate basilar or vertebral artery occlusion in the treatment of intracranial aneurysms
Authors: Steinberg Gary K. , Drake Charles G. , Peerless Sydney J.
Published: May 2009

✓ Deliberate occlusion of the basilar or vertebral arteries was performed in 201 patients with intracranial aneurysms, where the aneurysmal neck could not be clipped directly. The aneurysms arose from the basilar apex in 83 cases, the basilar trunk in 46, the vertebrobasilar junction in 35, and the vertebral artery in 37; 87% of the aneurysms were classified as giant lesions (> 2.5 cm). There were 85 upper basilar occlusions, 41 lower basilar occlusions, 29 bilateral vertebral occlusions, and 48 unilateral vertebral artery occlusions. The clinical follow-up period varied from 1 to 23 years, with a mean of 9.5 years. Overall long-term results were excellent in 68% of the patients, good in 5%, and poor in 3%; 24% died. Clinical outcome varied according to aneurysm site; excellent or good results were achieved in 64% of the patients with basilar apex, 76% with basilar trunk, 74% with vertebrobasilar junction, and 87% with vertebral artery aneurysms. Clinical outcome also varied depending on preoperative grade: 86% of the patients with an excellent presenting grade achieved excellent results. The size of the posterior communicating arteries was a good predictor of tolerance to basilar artery occlusion (p < 0.05). Successful aneurysm thrombosis was achieved in 78% of the patients.

The neurological status in 26 patients (13%) deteriorated due to vertebrobasilar ischemia occurring within the 1st postoperative week, and thrombosis or embolism was implicated much more frequently than hemodynamic insufficiency. Subarachnoid hemorrhage (SAH) in 14 patients, vasospasm in five patients, and surgical trauma in seven patients accounted for additional morbidity in the 1st month following operation; however, many of these patients ultimately made an excellent recovery. Late vertebrobasilar ischemic complications or neurological deterioration from persistent mass effect occurred in 4% of patients with successful aneurysm thrombosis 6 weeks to 18 months after arterial ligation. Among the 43 patients with incompletely thrombosed aneurysms, 67% developed early or late neurological deterioration from SAH, progressive brain-stem compression, or brain-stem stroke, with 86% of the complications proving fatal.
Idiopathic hypertrophic cranial pachymeningitis
Authors: Mamelak Adam N. , Kelly William M. , Davis Richard L. , Rosenblum Mark L.
Published: May 2009

✓ Hypertrophic cranial pachymeningitis is a rare, idiopathic form of granulomatous pachymeningitis. This report describes three cases of hypertrophic cranial pachymeningitis and discusses the clinical, radiographic, and pathological findings in these and other reported cases. These lesions typically cause progressive cranial nerve palsies, headaches, and cerebellar dysfunction. They occur in patients of all age groups; the peak incidence is in the sixth decade. Hypertrophic cranial pachymeningitis is best identified by magnetic resonance imaging. The diagnosis is established by excluding all other granulomatous and infectious diseases. A dural biopsy is essential to confirm the diagnosis. Hypertrophic cranial pachymeningitis is initially responsive to steroid therapy, but in most cases it recurs or progresses despite treatment. Surgical excision of granulomas is occasionally necessary to alleviate a mass effect. The long-term outcome remains uncertain for most patients, but progressive disease is usually fatal owing to cranial neuropathies.
A frameless stereotactic approach to neurosurgical planning based on retrospective patient-image registration
Authors: Tan Kim K. , Grzeszczuk Robert , Levin David N. , Pelizzari Charles A. , Chen George T. Y. , Erickson Robert K. , Johnson Douglas , Dohrmann George J.
Published: May 2009

✓ A frameless stereotactic device interfacing an electromagnetic three-dimensional (3-D) digitizer to a computer workstation is described. The patient-image coordinate transformation was found by retrospectively registering a digitizer-derived model of the patient's scalp with a magnetic resonance (MR) imaging-derived model of the same surface. This procedure was performed with routine imaging data, eliminating the need to obtain special-purpose MR images with fiducial markers in place. After patient-image fusion was achieved, a hand-held digitizing stylus was moved over the scalp and tracked in real time on cross-sectional and 3-D brain images on the computer screen. This device was used for presurgical localization of lesions in 10 patients with meningeal and superficial brain tumors. The results suggest that the system is accurate enough (typical error range 3 to 8 mm) to enable the surgeon to reduce the craniotomy to one-half the size advisable with conventional qualitative presurgical planning.
The use of moderate therapeutic hypothermia for patients with severe head injuries: a preliminary report
Authors: Marion Donald W. , Obrist Walter D. , Earlier Patricia M. , Penrod Louis E. , Darby Joseph M.
Published: May 2009

✓ Animal research suggests that moderate therapeutic hypothermia may improve outcome after a severe head injury, but its efficacy has not been established in humans. The authors randomly assigned 40 consecutively treated patients with a severe closed head injury (Glasgow Coma Scale score 3 to 7) to either a hypothermia or a normothermia group. Using cooling blankets and cold saline gastric lavage, patients in the hypothermia group were cooled to 32° to 33°C (brain temperature) within a mean of 10 hours after injury, maintained at that temperature for 24 hours, and rewarmed to 37° to 38°C over 12 hours. Patients in the normothermia group were maintained at 37° to 38°C during this time. Deep-brain temperatures were monitored directly and used for all temperature determinations. Intracranial pressure (ICP), cerebral blood flow (CBF), and cerebral metabolic rate for oxygen (CMRO2) were measured serially for all patients.

Hypothermia significantly reduced ICP (40%) and CBF (26%) during the cooling period, and neither parameter showed a significant rebound increase after patients were rewarmed. Compared to the normothermia group, the mean CMRO2 in the hypothermia group was lower during cooling and higher 5 days after injury. Three months after injury, 12 of the 20 patients in the hypothermia group had moderate, mild, or no disabilities; eight of the 20 patients in the normothermia group had improved to the same degree. Both groups had a similar incidence of systemic complications, including cardiac arrhythmias, coagulopathies, and pulmonary complications. It is concluded that therapeutic moderate hypothermia is safe and has sustained favorable effects on acute derangements of cerebral physiology and metabolism caused by severe closed head injury. The trend toward better outcome with hypothermia may indicate that its beneficial physiological and metabolic effects limit secondary brain injury.
Anterior communicating artery collateral flow protection against ischemic change during carotid endarterectomy
Authors: Lopez-Bresnahan Maria V. , Kearse Lee A. , Yanez Paulino , Young Tina I.
Published: May 2009

✓ The purpose of this study was to determine whether preoperative angiographic patterns of collateral cerebral blood flow correlate with protection against intraoperative electroencephalographic (EEG) evidence of cerebral ischemia caused by carotid artery cross-clamping during carotid endarterectomy. Previous studies have shown that contralateral carotid artery occlusion and intracranial stenoses are associated with cerebral ischemia during carotid endarterectomy; however, the angiographic collateral flow patterns associated with cerebral ischemia have not been identified. This paper reports a retrospective study of 67 patients who underwent two- to four-vessel cerebral angiography followed by carotid endarterectomy with 16-channel EEG monitoring. The angiograms were reviewed for extracranial occlusive disease and collateral flow patterns, and the EEG recordings were analyzed for ischemic changes during carotid artery cross-clamping. Statistical analysis was by Fisher's exact test.

Cross-filling of the anterior and middle cerebral arteries from the contralateral carotid artery through the anterior communicating artery correlated with a decreased incidence of EEG ischemic changes. Only 21% of patients with this collateral flow pattern showed ischemic changes compared to 50% of patients without this pattern (p < 0.03). Three angiographic findings occurring in combination on the side contralateral to surgery correlated with EEG ischemia: 1) occlusion of the contralateral internal carotid artery (five of seven or 71%, p < 0.03); 2) collateral flow from the external carotid circulation to the internal carotid circulation via the ophthalmic artery; and 3) collateral flow from the posterior circulation to the contralateral anterior circulation via the posterior communicating artery. The data presented here corroborate the correlation between contralateral carotid artery occlusion and cerebral ischemia during carotid endarterectomy. They also demonstrate that cross-filling of the anterior and middle cerebral arteries by the contralateral carotid artery protects against such ischemia. This collateral flow may serve as an indicator of tolerance to carotid artery cross-clamping.
Evaluation of pressure changes in feeding arteries during embolization of intracerebral arteriovenous malformations
Authors: Handa Takashi , Negoro Makoto , Miyachi Shigeru , Sugita Kenichiro
Published: May 2009

✓ The pressure in 47 arteries feeding 21 arteriovenous malformations (AVM's) was investigated during transarterial embolization using a Tracker-18 microcatheter. On average, systolic pressure increased by 22 mm Hg. In AVM's with single or few feeders, embolization was usually achieved well; in contrast, giant AVM's with multiple feeders and a large arteriovenous shunt were poorly embolized. However, large AVM's with well-demarcated components may be reduced by embolization to an appropriate size for surgery or stereotactic radiation therapy. It was found that the feeding artery pressure increased significantly more in well-embolized than in poorly embolized cases. Measurement of the feeding artery pressure clarified the hemodynamics of AVM's and facilitated more successful embolization.
Percutaneous lateral cervical cordotomy: target localization with water-soluble contrast medium
Authors: Krol George , Arbit Ehud
Published: May 2009

✓ Water-soluble intrathecal contrast material was used for radiographic identification of the cord target in 13 patients undergoing percutaneous lateral cervical cordotomy. Adequate visualization of the dentate ligament, considered essential for successful placement of the electrode, was achieved in seven cases. In the remaining six patients, four with suboptimal definition and two with nonvisualization of the ligament, an additional injection of contrast medium using a modified coaxial needle system outlined the entire thickness of the cervical cord. This technique improved needle-tip positioning in relation to the cord and resulted in successful surgery in all six patients.
Urinary epidermal growth factor in patients with gliomas: significance of the factor as a glial tumor marker
Authors: Kanno Hiroshi , Chiba Yasuhiro , Kyuma Yoshikazu , Hayashi Akimune , Abe Hiroyuki , Takada Hiroto , Kim Ilu , Yamamoto Isao
Published: May 2009

✓ Epidermal growth factor (EGF) content in urine from patients with glial tumors was examined by radioimmunoassay techniques with labeled human EGF and its rabbit EGF polyclonal antibody. There was no cross-reaction with transforming growth factor-α, which has a common receptor with EGF. Forty glial tumors were divided into three groups according to the clinical stage: Samples from Group A patients were obtained before therapy and/or after biopsy; in these patients a large volume of tumor was apparent on computerized tomography (CT). Group B samples were obtained after gross total removal of the tumor and/or chemo- and radiation therapy; these patients showed a small volume of residual tumor on CT. Samples from Group C patients were obtained after gross tumor total removal and/or chemo- and radiation therapy; no tumor was detected on CT scans in these patients. Urinary EGF levels in Group A samples were statistically significantly higher than in samples from healthy individuals (p < 0.001), Group B patients (p < 0.10), and Group C patients (p < 0.02). In addition, high-grade glial tumors in Group A cases showed a significantly higher level of urinary EGF than low-grade tumors in Group A patients (p < 0.05), or patients with meningioma (p < 0.02), metastatic brain tumor (p < 0.05), and cerebral infarction (p < 0.001). Longitudinal changes of urinary EGF levels in glioma patients mostly synchronized with the clinical course and therapeutic interventions. Therefore, urinary EGF, as a glial tumor marker, may be of practical value for diagnosing a malignant glioma and evaluating for the efficacy of chemo- and radiation therapy.
Clival chordoma associated with pathological laughter
Authors: Matsuoka Shigeaki , Yokota Akira , Yasukouchi Hideoki , Harada Atsukuni , Kadoya Chitoshi , Wada Shin-Ichi , Ishikawa Tadahiro , Okuda Shinya
Published: May 2009

✓ The case of a 40-year-old man with a clival chordoma who presented with symptoms of pathological laughter and left sixth cranial nerve paresis is reported. Laughing and talking during sleep were noted on polygraphic and videotape recordings of nocturnal sleep. Selective disorganization of sleep was observed, with laughing facial expressions and a lack of muscular atonia. The tumor developed in the prepontine cistern, compressing the pontomesencephalic structures backward and involving the upper clivus and the left cavernous sinus. No recurrence of laughter attacks were noted after total removal of the tumor. The sleep patterns observed were similar to those of experimental animals with lesions of the peri-α locus ceruleus. The importance of uncontrolled laughter as a sign of a ventral brain-stem mass is emphasized.