bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term follow-up results of selective VIM-thalamotomy
Authors: Nagaseki Yoshishige , Shibazaki Tohru , Hirai Tatsuo , Kawashima Yasuhiro , Hirato Masafumi , Wada Hirochiyo , Miyazaki Mizuho , Ohye Chihiro
Published: May 2009

✓ The authors report the results of a long-term follow-up study of the effects of the physiologically defined selective VIM (nucleus ventralis intermedius)-thalamotomy on tremor of Parkinson's disease in 27 patients and essential tremor in 16 patients. The follow-up period ranged from 3.25 to 10 years (mean 6.58 years). In 43 patients a total of 50 operations (including four bilateral operations and three reoperations) were carried out. The early (2 to 4 weeks after surgery) and late effects on the tremors were determined clinically and electromyographically. Fourteen parkinsonian cases were treated with minimal lesions (about 40 cu mm). Their late results were very similar to the early results: in 10, the tremors were completely abolished, three had a slight residual tremor, and one underwent reoperation 3 months after the first surgery. Eleven essential tremor cases were treated with minimal lesions. Six of these tremors were completely abolished, four patients had slight residual tremors, and one patient with a recurrence underwent reoperation 2 years after the initial surgery. In these 23 successful operations with minimal lesions (excluding two cases with reoperation), the tremor was abolished without discernible long-lasting side effects. The other 23 operations on 16 patients with Parkinson's disease (including one reoperation) and on seven with essential tremor (one of whom also had a minimal lesion on the other side) involved relatively large lesions. In this group, the surgery was successful in almost every case. It was concluded that radiographically and physiologically monitored selective VIM-thalamotomy for parkinsonian and essential tremor is effective even when lesioning is minimal. Moreover, the beneficial effect is maintained over a long period of time.
Aneurysms protruding from the dorsal wall of the internal carotid artery
Authors: Nakagawa Fukuo , Kobayashi Shigeaki , Takemae Toshiki , Sugita Kenichiro
Published: May 2009

✓ Saccular aneurysms arising at locations other than at arterial divisions are extremely rare. The authors describe eight such aneurysms that protruded from the dorsal wall of the internal carotid artery (ICA) and were unrelated to any arterial junction. Radical surgery was performed in all eight cases. The aneurysms were saccular with a fragile wide or semifusiform neck. Intraoperative rupture occurred in three cases. From this experience, it is emphasized that these unusual protruding aneurysms of the dorsal ICA should be clipped with the clip blade parallel to the parent artery. In addition to clipping, complete wrapping with fascia or Bemsheet (cellulose fabric) is often advisable to prevent slippage of clips or postoperative rupture of residual aneurysm.
Clinical course of acute middle cerebral artery occlusion
Authors: Yoshimoto Takashi , Ogawa Akira , Seki Hirobumi , Kogure Tetsuo , Suzuki Jiro
Published: May 2009

✓ Knowledge of the natural course of stroke patients has become increasingly important since new therapeutic methods have been proposed for patients with cerebral infarction in the acute stage. In order to clarify the acute stage of this disease, 188 patients admitted within 24 hours after onset of middle cerebral artery (MCA) occlusion were followed for 2 months, and data relating to mortality and changes in disturbances of consciousness and motor function were investigated. It was shown that the prognosis for MCA occlusion cases is poor, and about 80% of these patients are unable to return to their previous lifestyle. The level of consciousness in the acute stage is a good index for estimating the patient's quality and time of survival, and motor function in the acute stage is a good indicator of functional recovery. Thus, when evaluating the effectiveness of a new therapy for cerebral infarction, rapid improvement in the acute stage before and after treatment should be carefully noted.
Cell kinetics analysis in a case of teratoma of the thoracic spine
Authors: Murovic Judith A. , De Armond Stephen , Nagashima Tadashi , Edwards Michael S. B. , Hoshino Takao
Published: May 2009

✓ The authors report cell kinetics studies in an infant who had multiple operations for removal of a rare benign thoracic spinal teratoma with retroperitoneal extension. Before the final surgical procedure for recurrent tumor, bromodeoxyuridine (BUdR), 200 mg/sq m, was administered intravenously to label tumor cells in the S (deoxyribonucleic acid (DNA) synthesis) phase of the cell cycle. Histologically, the tumor was a mature teratoma consisting of components derived from all three germ-cell layers. Cells labeled with BUdR were found in the basal layer of stratified squamous epithelia, in respiratory epithelia, in the cartilage and surrounding perichondrial mesenchyme, and in loose mesenchymal tissue throughout the teratoma. In contrast to neuroec-todermal tumors, which show widespread BUdR uptake throughout the tissue and which have different average labeling indices according to their histological type (range < 1 % to 15.2%), the teratoma showed BUdR labeling only in certain areas, indicating fairly organized growth patterns; the labeling indices in these areas ranged from 0.39% to 1.9%.
Muscle basal lamina: a new graft material for peripheral nerve repair
Authors: Fawcett James W. , Keynes Roger J.
Published: May 2009

✓ The suitability of muscle basal lamina as a graft material for the repair of peripheral nerves was investigated. Grafts were prepared by evacuating the myoplasm from muscles excised from rats and rabbits. This produced a material consisting mainly of basal lamina and connective tissue, with the basal lamina arranged as parallel tubes. Rat- and rabbit-derived graft material in 0.5-cm lengths was sutured into rat sciatic nerves, and 4-cm lengths of rabbit-derived graft material were interposed into rabbit sciatic nerves. For controls, 0.5-cm nerve autografts were grafted into rats and 4-cm autografts into rabbits. After 2 to 3 months, the success of the grafts was assessed functionally, electrophysiologically, and anatomically. By all these criteria the basal lamina grafts were as successful as nerve autografts; essentially the same number of axons of the same size grew through both graft types, animals recovered their limb function equally well, and the nerve conduction velocities and relative refractory periods were the same in both groups of animals. In rats, following both basal lamina and nerve autografts, the number of axons distal to the grafts was approximately the same as that proximal to them, but axon diameter and speed of conduction were significantly less than normal. The authors conclude that muscle basal lamina grafts are as effective as nerve autografts for repairing severed rat or rabbit peripheral nerves, and suggest that grafts prepared in this way may prove to be useful for nerve repair in humans.
Distribution of hematoporphyrin derivative in canine glioma following intraneoplastic and intraperitoneal injection
Authors: Steichen John D. , Dashner Kathleen , Martuza Robert L.
Published: May 2009

✓ Hematoporphyrin derivative (HPD) is a photosensitizing agent that has been used to locate and kill tumors. The distribution of tritiated (3H)-HPD was studied in a transplantable canine glioma model following intraperitoneal or direct intraneoplastic injection. Compared to intraperitoneal adminstration of 3H-HPD, direct injection resulted in levels that were more than 2.5 times higher in tumor tissue and approximately 10 times lower in skin. Dose-corrected analysis of the data indicated that outside the central nervous system (CNS) the distribution of 3H-HPD is dose-related, regardless of route of injection. Within the CNS, direct injection leads to more efficient uptake of 3H-HPD, especially at the tumor periphery. Fluorescence microscopy confirmed the selective biodistribution of HPD fluorescence within the cytoplasm of tumor cells.
A role of the central catecholamine neuron in cerebral circulation
Authors: Yokote Hideyoshi , Itakura Toru , Nakai Kunio , Kamei Ichiro , Imai Harumichi , Komai Norihiko
Published: May 2009

✓ The effect of the central catecholaminergic neurons on the cerebral microcirculation was investigated by means of a unilateral intracerebral injection of 6-hydroxydopamine (6-OHDA) which produced the degeneration of catecholamine (CA) nerve terminals. Subsequent observation with CA histofluorescence revealed an absence of CA fibers in the vicinity of the 6-OHDA injection site. A significant increase in regional cerebral blood flow (rCBF), measured by the hydrogen clearance method, was demonstrated in the CA-depleted cortex under normocapnia as compared with rCBF in the control cortex (CA-depleted cortex 47.0 ± 2.8 ml/100 gm/min; control cortex 38.5 ± 3.5 ml/100 gm/min; p < 0.005). The increased rCBF in the cortex treated with 6-OHDA was suppressed by the iontophoretic replacement of noradrenaline (NA) to the CA-depleted cortex. An iontophoretic replacement of 10−5 M dopamine (DA) mildly suppressed the increased rCBF in the 6-OHDA-treated cortex. The CO2 reactivity in the CA-depleted cortex was significantly lower than that of the control cortex (CA-depleted cortex 2.13% ± 0.67%/mm Hg; control cortex 3.53% ± 0.70%/mm Hg). No change was noticeable in the cerebral glucose metabolism in the CA-depleted cortex in an investigation based on tritiated (3H)-deoxyglucose uptake. It is suggested that the 6-OHDA-induced change in cerebral blood flow (CBF) is not secondary to alterations in cerebral metabolic rate, and that the central NA neuron system innervating intraparenchymal blood vessels regulates CBF through a direct vasoconstrictive effect on the cerebral blood vessels. The central DA neuron system may modulate the cerebral circulation as a mild vasoconstrictor.
Neuroepithelial (colloid) cyst of the third ventricle in identical twins
Authors: Ibrahim Abdel Wahab M. , Farag Hisham , Naguib Mohammed , Ibrahim Ezzeldin
Published: May 2009

✓ Colloid cysts of the third ventricle are described in middle-aged twin brothers. One of them presented with recurrent attacks of headache. In this patient the cyst had reached a size large enough to obstruct the cerebrospinal fluid pathway, resulting in hydrocephalus. The twin brother, although asymptomatic, was suspected of the anomaly and investigated because of the similarity of his ocular signs. The diagnosis was confirmed by computerized tomography in both the patient and his brother. The latter proved to have a smaller colloid cyst situated anteriorly in the third ventricle with no obstructive hydrocephalus. The patient was successfully operated on, while the brother is still under observation. Both brothers have had bilateral cataracts, retinal detachments, and left lateral rectus palsies. The familial occurrence of colloid cysts and their association with these ocular findings have apparently not been described before.
Vertebrectomy for treatment of vertebral hemangioma without preoperative embolization
Authors: Feuerman Tony , Dwan Paul S. , Young Ronald F.
Published: May 2009

✓ Vertebral hemangiomas have usually been treated by resection following preoperative arterial embolization. A case is presented in which no feeding tumor vessels were demonstrable angiographically. The tumor was resected by an arterolateral transthoracic approach without preoperative embolization. There was progressive postoperative improvement of the myelopathy.
Computerized tomographic and magnetic resonance imaging of intracranial lipoma
Authors: Friedman Robert B. , Segal Ricardo , Latchaw Richard E.
Published: May 2009

✓ Intracranial lipoma is an uncommon lesion that has been well described in both the neurosurgical and neuroradiological literature for many years. This lesion is usually only an incidental finding, but it may be symptomatic. The authors describe a case of symptomatic intracranial lipoma of the superior medullary velum with emphasis on the correlation between computerized tomography and magnetic resonance imaging in evaluation of the lesion.
MRI demonstration of clot in a small unruptured aneurysm causing stroke
Authors: Eller Theodore W.
Published: May 2009

✓ The case is reported of a 69-year-old woman with an 18-mm unruptured aneurysm of the right middle cerebral artery which caused a moderate stroke. Magnetic resonance imaging revealed a clot inside the aneurysm that was not visible on computerized tomography scans. The danger of embolism from the clot prompted clipping of the aneurysm.
Balloon embolization of a large distal basilar artery aneurysm
Authors: Hieshima Grant B. , Higashida Randall T. , Wapenski Joseph , Halbach Van V. , Cahan Leslie , Bentson John R.
Published: May 2009

✓ Interventional neurovascular techniques have advanced to a level where treatment of intracranial aneurysms by intravascular detachable balloon embolization therapy is now possible. A patient is presented who had a spontaneous subarachnoid hemorrhage from a large aneurysm of the distal basilar artery. The aneurysm arose at the bifurcation of the posterior cerebral arteries and measured 15 × 9 × 9 mm. With the patient fully awake, a detachable silicone balloon was passed into the basilar artery by a transfemoral arterial approach. Stenosis (> 60%) of the mid-section of the basilar artery, secondary to arterial vasospasm from the recent hemorrhage, was present. The stenosis was treated by transluminal angioplasty, after which the balloon was passed into the aneurysm and detached. A follow-up angiogram 3 months later demonstrated complete occlusion of the aneurysm and a widely patent basilar artery at the angioplasty site.
Discrepancies among CT, histological, and blood-brain barrier findings in early cerebral ischemia
Authors: Kuroiwa Toshihiko , Seida Mitsuru , Tomida Shuuichi , Hiratsuka Hideo , Okeda Riki , Inaba Yutaka
Published: May 2009

✓ The development of ischemic edema and blood-brain barrier (BBB) disruption during the 1st day of experimental cerebral infarction induced by transorbital occlusion of the middle cerebral artery (MCA) in cats was evaluated by computerized tomography (CT) scanning and compared to gravimetric and pathological studies. Regional cerebral blood flow was measured using the hydrogen clearance technique or stable xenonenhanced CT scanning. Edema was observed gravimetrically and microscopically as early as 1 hour after the onset of ischemia in the cortex and at 3 hours or later in both the cortex and white matter. However, a significant decrease of Hounsfield numbers on the CT scans was not detectable at 1 or 3 hours and was scarcely visible at 9 hours after occlusion. Disruption of the BBB was detected by leakage of Evans blue dye at 3 hours after the occlusion in two of six animals and at 9 hours in five of five animals. However, CT scanning after infusion of contrast material showed no significant increase in Hounsfield number even 24 hours after MCA occlusion. These discrepancies should be emphasized when the dynamics of ischemic edema and BBB disruption are evaluated for clinical therapy by CT scanning.
Air in acute epidural hematomas
Authors: Aoki Nobuhiko
Published: May 2009

✓ Two pediatric patients with acute epidural hematomas containing air bubble(s) are reported. A skull fracture was observed extending to the mastoid cells of the temporal bone in both patients. In one patient the hematoma and air bubbles subsequently increased in volume, requiring a craniotomy. The clinical significance of air in an acute epidural hematoma is discussed.
Splitting of the optic nerve by a carotid-ophthalmic artery aneurysm
Authors: Beatty Robert A.
Published: May 2009

✓ A patient with splitting of the optic nerve by a carotid-ophthalmic artery aneurysm is presented. Possible explanations for this previously unreported configuration are discussed.
Radiopaque synthetic sponge as a prosthesis for microvascular decompression
Authors: Nagata Kazuya , Sasaki Tomio , Basugi Norihiko
Published: May 2009

✓ A radiopaque synthetic sponge is proposed as a prosthesis for microvascular decompression. Displacement of the prosthesis can be easily detected on a plain x-ray skull film.
Primary malignant lymphoma of the central nervous system
Authors: Murray Kevin , Kun Larry , Cox James
Published: May 2009

✓ Eleven patients with primary malignant lymphoma of the central nervous system (CNS) were treated at the Medical College of Wisconsin Affiliated Hospitals between 1964 and 1984. Three patients had a prior history of immunosuppressive therapy following renal transplantation. All patients had biopsy-proven disease and 10 of the 11 were treated with external radiation therapy. The doses to the primary tumor ranged from 34 to 59.4 Gray (Gy). Actuarial (life-table) survival rate was 82% at 1 year and 43% at 3 years. No recurrence was seen after 13 months.

Eighty-six reports totaling 693 cases of primary malignant lymphoma of the CNS were found in the literature. Of these, 308 cases were treated with a combination of surgery and irradiation. Overall survival at 5 years for those patients who received more than 50 Gy compared with less than 50 Gy to the primary tumor was 42.3% versus 12.8% (p < 0.05). Twenty-one patients survived longer than 5 years. Late relapse was notable, with 10 (47.6%) of 21 tumors recurring between 5 and 12.5 years after diagnosis. Based on this review, a minimum of 50 Gy radiation to the primary tumor is recommended. While no statement regarding the efficacy of craniospinal irradiation or chemotherapy can be made in view of the small numbers, the use of craniospinal irradiation and/or systemic chemotherapy should be considered for future trials.
Chronic expanding intracerebral hematoma
Authors: Pozzati Eugenio , Giuliani Giuliano , Gaist Giulio , Piazza Giancarlo , Vergoni Gilberto
Published: May 2009

✓ The cases of 10 normotensive patients with chronic intracerebral hematomas are reported. The patients' median age at diagnosis was 42 years. The median duration of symptoms was 22 days. Seizures were thepresenting symptom in 50% of the cases. Computerized tomography almost consistently demonstrated ring-shaped lesions with mass effect and perifocal edema. Arteriography revealed that all but one of the lesions were avascular. All patients had superficial white matter lesions, mostly in the frontoparietal region. All patients were treated surgically. Most of the hematomas were encapsulated and contained blood in various stages of organization. The thick capsule consisted of an outer layer of collagenous tissue and an inner layer of granulation tissue. Occult cerebrovascular malformations were detected in two instances.

There were two deaths, both related to recurrent postoperative hemorrhage. This entity can present much like a brain malignancy and should be considered in the differential diagnosis of ring-shaped lesions whatever the clinical presentation. Strategies of treatment are discussed.
Cerebral perfusion pressure, intracranial pressure, and head elevation
Authors: Rosner Michael J. , Coley Irene B.
Published: May 2009

✓ Previous investigations have suggested that intracranial pressure waves may be induced by reduction of cerebral perfusion pressure (CPP). Since pressure waves were noted to be more common in patients with their head elevated at a standard 20° to 30°, CPP was studied as a function of head position and its effect upon intracranial pressure (ICP).

In 18 patients with varying degrees of intracranial hypertension, systemic arterial blood pressure (SABP) was monitored at the level of both the head and the heart. Intracranial pressure and central venous pressure were assessed at every 10° of head elevation from 0° to 50°. For every 10° of head elevation, the average ICP decreased by 1 mm Hg associated with a reduction of 2 to 3 mm Hg CPP. The CPP was not beneficially affected by any degree of head elevation. Maximal CPP (73 ± 3.4 mm Hg (mean ± standard error of the mean)) always occurred with the head in a horizontal position. Cerebrospinal fluid pressure waves occurred in four of the 18 patients studied as a function of reduced CPP caused by head elevation alone. Thus, elevation of the head of the bed was associated with the development of CPP decrements in all cases, and it precipitated pressure waves in some. In 15 of the 18 patients, CPP was maintained by spontaneous 10- to 20-mm Hg increases in SABP, and pressure waves did not occur if CPP was maintained at 70 to 75 mm Hg or above.

It is concluded that 0° head elevation maximizes CPP and reduces the severity and frequency of pressure-wave occurrence. If the head of the bed is to be elevated, then adequate hydration and avoidance of pharmacological agents that reduce SABP or prevent its rise are required to maximize CPP.
Estimation of growth fraction with bromodeoxyuridine in human central nervous system tumors
Authors: Yoshii Yoshihiko , Maki Yutaka , Tsuboi Koji , Tomono Yuji , Nakagawa Kunio , Hoshino Takao
Published: May 2009

✓ Twenty-five patients with tumors of the central nervous system received bromodeoxyuridine (BUdR), 200 mg/sq m, by intravenous infusion every 8 hours for 3 days before surgery. Excised tumor specimens were fixed in chilled 70% ethanol, embedded in paraffin, and cut into 6-µm sections. Each section was reacted with monoclonal antibodies against BUdR and stained with immunoperoxidase to identify nuclei that had incorporated BUdR. The growth fraction of each tumor was estimated by calculating the ratio of BUdR-positive nuclei to the total number of tumor cells in three to six microscopic fields in viable areas of the tumor. In seven cases, the tumor doubling time was measured from the serial computerized tomography scans and an attempt was made to estimate the cell cycle time.

The growth fractions ranged from 9.1% to 46.5% in malignant gliomas, 2.0% to 6.7% in low-grade gliomas, 11.2% to 43.2% in metastatic brain tumors, 0.8% to 1.9% in pituitary adenomas, 3.9% to 4.6% in acoustic neurinomas, and 6.2% to 8.2% in meningiomas and cerebellar hemangioblastomas. The estimated cell cycle time was 5 to 12 days in most malignant gliomas and brain metastases; however, the actual cell cycle time should be substantially shorter because cell loss was not considered in the calculation. Although the growth fraction appeared to correlate with the biological malignancy of each tumor, the tumor doubling time did not reflect growth potential. It is possible that unpredictable cell loss plays an important role in tumor growth at certain sizes. Therefore, the cell cycle times calculated in this study are considerably overestimated and should be interpreted with caution.
Effect of hyperglycemia on brain pH levels in areas of focal incomplete cerebral ischemia in monkeys
Authors: Marsh W. Richard , Anderson Robert E. , Sundt Thoralf M.
Published: May 2009

✓ The adverse effect of a minimal cerebral blood flow (CBF) in models of global ischemia has been noted by many investigators. One factor believed important in this situation is the level of blood glucose, since a continued supply of this metabolite results in increased tissue lactate, decreased brain pH, and increased cell damage. The authors have extended these observations to a model of focal incomplete ischemia. Brain pH was measured in fasted squirrel monkeys in regions of focal incomplete ischemia after transorbital occlusion of the middle cerebral artery (MCA). In both control and hyperglycemic animals, CBF was reduced to less than 30% of baseline. At 3 hours after MCA occlusion, brain pH in the control group was 6.66 ± 0.68 as compared to 6.27 ± 0.26 in the glucose-treated group. This difference was statistically significant by Student's unpaired t-test (p < 0.05). Thus, hyperglycemia results in decreased tissue pH in regions of focal incomplete cerebral ischemia in monkeys.
Early hemodynamic changes in experimental intracerebral hemorrhage
Authors: Nath Fredrik P. , Jenkins Alistair , Mendelow A. David , Graham David I. , Teasdale Graham M.
Published: May 2009

✓ A model of experimental intracerebral hemorrhage is described in which carefully controlled volumes of autologous blood were injected at arterial pressure into the caudate nucleus of the rat. A comparison of intracranial pressure changes and local cerebral blood flow (CBF) was made between three groups of rats, each receiving different injection volumes, and sham-operated control rats by monitoring intraventricular pressure and by obtaining quantitative autoradiographic measurements of CBF within 1 minute of the experimental hemorrhage. Cerebral blood flow was reduced both around the hematoma and in the surrounding brain. This change was strongly volume-dependent and was not accompanied by significant alterations in cerebral perfusion pressure. This finding suggests that the degree of ischemia at the time of an intracerebral bleed depends on the size of the lesion, and implicates local squeezing of the microcirculation by the hematoma, rather than a generalized alteration in perfusion pressure, as the cause of ischemia.
Leptomeningeal cyst of the posterior fossa
Authors: Nemoto Shigeru , Hoffman Harold J.
Published: May 2009

✓ A patient with a posttraumatic leptomeningeal cyst is described. The cyst simulated an occipital encephalocele and communicated with an epidural cerebrospinal fluid collection in the posterior fossa.
Lead encephalopathy presenting as a posterior fossa mass
Authors: Harrington J. Frederick , Mapstone Timothy B. , Selman Warren R. , Galloway Pamela , Bundschuh Carl
Published: May 2009

✓ A case of lead encephalopathy with clinical and computerized tomography evidence of a midline posterior fossa mass is presented. The pathophysiology and the predilection for posterior fossa involvement are discussed.
Prognostic factors in pediatric brain-stem gliomas
Authors: Albright A. Leland , Guthkelch A. Norman , Packer Roger J. , Price Robert A. , Rourke Lucy B.
Published: May 2009

✓ The clinical, computerized tomography (CT), and histological findings from 84 children with brain-stem gliomas were reviewed to determine whether any of these features correlated with outcome. Clinical data were available from all children, CT data from 62 children, and biopsy data from 54 children. Actuarial life tables were constructed for each clinical, CT, and histological feature and the differences between these were analyzed. The period of survival was significantly shorter in children who presented with cranial nerve palsies (p < 0.0001), and such children were more likely to have malignant tumors. Two CT features correlated with a significantly decreased survival time: a hypodense tumor prior to contrast administration and a tumor that involved the entire brain stem. Tumor enhancement was not associated with any alteration in survival times. Children with tumor biopsies that were histologically benign survived significantly longer than those whose tumors were malignant (p < 0.0001). The histological feature associated with the poorest survival time was the presence of mitoses; features associated with the best prognosis were Rosenthal fibers and calcification. The data indicate that brain-stem gliomas are not a homogeneous group of tumors as far as their clinical, CT, and pathological features are concerned. These features may be useful in assessing prognosis and in developing future treatment protocols.
Intraspinal lipomas with spina bifida
Authors: Pierre-Kahn Alain , Lacombe Jacques , Pichon J. , Giudicelli Yves , Renier Dominique , Sainte-Rose Christian , Perrigot M. , Hirsch Jean-François
Published: May 2009

✓ The authors present a series of 73 cases of intraspinal lipomas in the lumbosacral region. Sixty-four patients were operated on, 43 of these under intraoperative monitoring of neural function. The results of this series and of major series published in the past 10 years demonstrate both the potential severity of these lesions (which are responsible for progressive neurological deficits in 56% of affected cases) and the benignity of their surgical treatment. The authors emphasize the usefulness of systematic early surgical treatment of these lesions.
Direct intracavernous obliteration of high-flow carotid-cavernous fistulas
Authors: Isamat Fabian , Ferrer Enrique , Twose Jorge
Published: May 2009

✓ Four cases of high-flow carotid-cavernous sinus fistula (CCF), three of them posttraumatic and one spontaneous, have been treated by a direct surgical approach to the cavernous sinus. The CCF's were obliterated by the introduction into the cavernous sinus of muscle fragments and/or fibrin sealant. In the three cases witha preoperatively patent internal carotid artery (ICA), the CCF was occluded and the ICA flow preserved. One of these also had a posttraumatic false aneurysm that enclosed the two avulsed ends of a transected intracavernous ICA. This was treated by cervical ICA ligation following resolution of the CCF. A fourth patient, who had previously undergone an unsuccessful ICA trapping procedure elsewhere, also obtained a good result. The case histories and the surgical technique are presented. Direct intracavernous obliteration with muscle fragments and fibrin sealant fulfills the criteria for treatment of high-flow CCF's: occlusion of the arteriovenous fistula and preservation of the ICA circulation. While this surgical technique is a therapeutic option in some cases, it appears to have precise indications in others.
Prediction of tumor doubling time in recurrent meningiomas
Authors: Cho Kyung G. , Hoshino Takao , Nagashima Tadashi , Murovic Judith A. , Wilson Charles B.
Published: May 2009

✓ Eight patients with recurrent meningiomas (four malignant, two hemangiopericytic, and two nonmalignant) were given intravenous bromodeoxyuridine (BUdR), 200 mg/sq m, at the time of surgery to label cells in the deoxyribonucleic acid (DNA) synthesis phase; labeled cells were detected in excised tumor specimens by immunoperoxidase staining using anti-BUdR monoclonal antibody. These tumors showed a wide range of BUdR labeling indices (LI's), calculated as the percentage of BUdR-labeled cells divided by the total number of cells scored, from 0.3% to 5.4%. The tumor doubling times (Td's), estimated from serial computerized tomography scans, ranged from 8 to 440 days and showed a close inverse correlation with the BUdR LI's. A semilogarithmic linear regression analysis of these values yielded a correlation coefficient of 0.99. Tumor doubling time (Td) can be estimated using the formula: Td = 500 × Exp (−0.73 × LI), where Exp signifies the natural log base. By predicting the growth rate of meningiomas, the BUdR LI may supplement histopathological diagnosis and improve both the determination of prognosis and the design of treatment modalities in individual patients.
Brain-tumor cell kinetics correlated with survival
Authors: Bookwalter J. William , Selker Robert G. , Schiffer Lewis , Randall Margaret , Iannuzzi Debra , Kristofik Matthew
Published: May 2009

✓ In a review of 38 glioblastoma patients for whom fresh tissue kinetic data were available before any therapy was instituted, no correlation between the labeling index and survival time could be statistically determined. This relationship seems entirely consistent with the published theoretical determinants of tumor behavior: that is, altered ability for growth arrest and differentiation, constantly evolving mutant sublines, genetic instability, and an ever-changing metabolic and vascular environment.
Intraoperative spinal somatosensory evoked potential monitoring
Authors: Dinner Dudley S. , Lüders Hans , Lesser Ronald P. , Morris Harold H. , Barnett Gene , Klem G.
Published: May 2009

✓ The relationship of intraoperative monitoring of spinal cord somatosensory evoked potentials and postoperative deficit in 220 cases (121 with scoliosis, 41 with neoplasms, and 58 others) is reported. Bilateral posterior tibial nerve stimulation was used in 181 cases and unilateral median nerve stimulation in 39. Spinal cord (interspinous ligament needles), subcortical (neck surface), and cortical (scalp surface) SEP's were monitored. Seven patients had worsening of neurological function after surgery, three of whom demonstrated significant changes in SEP's monitored. In an additional four cases, there was more than a 50% decrease in amplitude of subcortical/cortical SEP's during monitoring, but no change in neurological status postoperatively. Combined monitoring of spinal cord, subcortical, and cortical SEP's enhanced the certainty of detecting spinal cord dysfunction even though there was a significant number of false-negative and false-positive results. A marked change in the SEP's indicated a high chance of developing a neurological deficit (three or 43% of seven cases), and if there was no change the chance of any neurological postoperative deficit was extremely low (four or 1.87% of 213 cases). These data justify the use of intraoperative SEP monitoring.
Role of EEG monitoring and cross-clamping duration in carotid endarterectomy
Authors: Collice Massimo , Arena Orazio , Fontana Romero A. , Mola Manuela , Galbiati Nora
Published: May 2009

✓ The usefulness of electroencephalographic (EEG) monitoring as well as the significance of the period of cross clamping in carotid endarterectomy have not been completely defined. In particular, the clinical importance of major EEG changes has not been fully investigated and some recent studies seem to indicate that the method has little value. As to the duration of cross clamping, there is strong evidence that occlusion times of about 15 minutes are tolerated under general anesthesia, but no information is available regarding longer periods of occlusion.

The authors describe a consecutive series of 141 carotid endarterectomies in which the patients with EEG changes were shunted only when occlusion was anticipated to last longer than 30 minutes. Early major EEG changes (during the first 4 minutes) occurred in 14% of the cases. In the absence of EEG changes, long occlusion periods of 40 to 50 minutes were well tolerated. In contrast, the 20 patients with major persistent EEG changes did not tolerate protracted occlusion and three of them had immediate postoperative neurological complications. It seems that, in these circumstances, the incidence of neurological deficit is a function of the duration of cross clamping: these three patients had undergone occlusion for 15 to 30 minutes. Their deficits partially resolved.

On the basis of these results it is concluded that: 1) EEG recording is a reliable monitoring system in carotid artery cross clamping. No major strokes due to temporary carotid artery occlusion occurred in the series. 2) The clinical significance of major persistent EEG changes is not negligible. Cross clamping for longer than 15 minutes in the presence of significant EEG alterations is potentially dangerous.
Comparison of mannitol regimens in patients with severe head injury undergoing intracranial monitoring
Authors: Smith Harold P. , Kelly David L. , McWhorter Joe M. , Armstrong Darlene , Johnson Rayetta , Transou Carole , Howard George
Published: May 2009

✓ Eighty patients sustaining head injuries and presenting with Glasgow Coma Scale scores of 8 or less were entered into a prospective randomized study to assess the benefit of intracranial pressure (ICP) monitoring with two regimens of mannitol administration. Group I was treated with mannitol for ICP elevations greater than 25 mm Hg, while Group II received empirical mannitol therapy irrespective of ICP readings. No statistically significant differences in mortality rate or neurological outcome were demonstrated between the two groups. These results are comparable to those of several published series of head-injured patients receiving similar treatment from 1977 to 1982. However, those series must be reassessed in light of recently published studies with treatment initiated at lower levels of ICP.
Beagle puppy model of perinatal cerebral infarction
Authors: Ment Laura R. , Stewart William B. , Duncan Charles C. , Pitt Bruce R. , Cole Judith S.
Published: May 2009

✓ Perinatal cerebral infarction, or stroke, is a not uncommon finding in newborns who survive after intensive care. Asphyxia, with its component parts hypoxemia and hypotension, represents the most common cause of perinatal cerebral infarction and may result in neuropathological changes in the periventricular white matter. Previous studies have demonstrated regional alterations in cerebral blood flow (CBF) in response to hypoxemic insult. This work examines the effects of hypoxemia on regional cerebral prostaglandin levels in the developing brain, since some observers believe that local CBF is controlled in part by prostaglandins. In this study, newborn beagle pups were anesthetized, subjected to tracheotomy and artificially ventilated to maintain normoxemia and normocarbia. Mean arterial blood pressure (MABP) was continuously monitored by means of an indwelling catheter and transducer, and craniectomies were performed. When the pups were physiologically stabilized, they were randomly assigned to receive acute hypoxemic insult (pO2 14.0 ± 1.55 mm Hg, mean ± standard deviation) accomplished by altering the oxygen concentration in the inspired air) or to receive no insult (mean pO2 84.3 ± 13.0 mm Hg). Fifteen minutes following stable hypoxemic or normoxic conditions, all pups underwent in vivo freezing of the intracranial contents under anesthesia followed by rapid sacrifice.

No significant differences were noted between the MABP, pH, or pCO2 values for the control and hypoxemic pups during the experimental period. Regional cerebral prostaglandin data demonstrated a significant increase in prostaglandin (PG)E2 in the gray matter of hypoxemic pups when compared to the normoxic controls (p < 0.02). No significant differences were noted for 6-keto-PGE1α, the stable metabolite of prostacyclin, or thromboxane (TX)B2, the stable metabolite of TXA2, in the gray matter. In addition, although 6-keto-PGE1α was significantly lower in the periventricular white matter of the hypoxemic pups (p < 0.05), there were no changes in the white matter in either PGE2 or TXA2. This regional differential synthesis of PGE2 in response to hypoxemic insult may explain the relative failure of CBF to the periventricular white matter and thus the neuropathological alterations attributed to it.
Spontaneous cerebellar hematoma associated with chronic cerebellar stimulation
Authors: Zuccarello Mario , Sawaya Raymond , Lukin Robert , deCourten-Myers Gabrielle
Published: May 2009

✓ A 24-year-old man developed a spontaneous cerebellar hematoma 5 years after the implantation of cerebellar electrodes. No vascular malformations were found either intraoperatively or radiographically. The histopathological findings of the cerebellar tissue obtained at biopsy from the region surrounding the electrodes support the hypothesis of a causal relationship between the spontaneous cerebellar hemorrhage and chronic cerebellar stimulation.
Radiation therapy for neoplasms of the brain
Authors: Leibel Steven A. , Sheline Glenn E.
Published: May 2009

✓ The effectiveness and complications of radiation therapy for brain neoplasms are reviewed. While the available data suggest a favorable influence and outcome, randomized studies are needed to further optimize radiation therapy techniques and to integrate new therapeutic modalities.
Use of detachable balloons for proximal artery occlusion in the treatment of unclippable cerebral aneurysms
Authors: Fox Allan J. , Viñuela Fernando , Pelz David M. , Peerless Sydney J. , Ferguson Gary G. , Drake Charles G. , Debrun Gerard
Published: May 2009

✓ Of 68 patients with unclippable aneurysms treated by proximal artery occlusion with detachable balloons, permanent occlusion was achieved in 65; of these patients, 37 had carotid artery aneurysms below the origin of the ophthalmic artery, 21 had aneurysms arising from the supraclinoid portion of the carotid artery, six had basilar trunk aneurysms, and one had a distal vertebral aneurysm. Examination for treatment selection included assessment of the circle of Willis by compression angiography and xenon blood flow studies, with the ultimate evaluation being test occlusion under systemic heparinization with the balloon temporarily placed in the desired position. Of 67 patients who underwent a formal occlusion test, eight with carotid artery aneurysms did not initially tolerate the occlusion test, and ischemic signs disappeared instantaneously with deflation and removal of the balloon. During test occlusion, two additional patients had ischemic events that proved to be embolic; these reversed immediately upon balloon deflation.

Of the 65 patients in whom permanent occlusion was effected by detachable balloon, there were nine instances of delayed cerebral events. One of these was a seizure leading to respiratory arrest and resuscitation 3 days following occlusion in a patient who had presented with seizures. The other eight cases were delayed ischemic events; seven were completely reversed and one patient had residual weakness in one leg (1.5% permanent morbidity). Extracranial-intracranial bypass procedures were performed in 25 of the 65 cases. All aneurysms of the carotid artery below the level of the ophthalmic artery presented angiographic proof of complete thrombosis. Ten of 21 aneurysms arising from the supraclinoid portion of the carotid artery were completely thrombosed by proximal occlusion alone, without additional trapping procedures. Similarly, in three of six basilar trunk aneurysms, proximal occlusion alone initiated complete aneurysm thrombosis without trapping. The conclusion is that proximal balloon occlusion for unclippable cerebral aneurysms is a convenient, safe, and effective way of producing arterial occlusion in these cases.
Temporoparietal craniopagus
Authors: Bucholz Richard D. , Yoon Kong-Woo , Shively Raymond E.
Published: May 2009

✓ A case of craniopagus twins joined in the temporoparietal area is presented, along with a review of the literature on craniopagus. A large area of brain was shared between the neurologically normal infants, with defects in the scalp, skull, and dura. The twins were separated in a three-step procedure. First, areas of shared brain were divided and separated with silicone sheets. The second procedure consisted of the insertion of scalp expanders to allow primary skin closure. In the third procedure complete separation was performed which was complicated by severe hypotension in one infant that was due to dural sinus hemorrhage. Cerebrospinal fluid leak was the most difficult problem encountered in the postoperative period; this was treated with lumboperitoneal and ventriculoperitoneal shunts. After 2 years, one twin is neurologically normal; the other is severely developmentally delayed, possibly related to the severe hypotension experienced during the third procedure. A review of the literature on craniopagus is presented. Analysis of data in the literature suggests that the area involved in the craniopagus as well as the venous connections are closely related to survival following separation of craniopagus twins.
A review of the factors influencing the prognosis of medulloblastoma
Authors: Caputy Anthony J. , McCullough David C. , Manz Herbert J. , Patterson Kathleen , Hammock Mary Kathryn
Published: May 2009

✓ The clinical, therapeutic, and histological features of 54 patients with medulloblastoma were analyzed retrospectively by a multivariate approach with regard to prognosis. The overall 5-year survival rate was 60%, with 48% of patients free of recurrence at 5 years. Cell differentiation, when present, was associated with a significantly longer recurrence-free period. Seventy-two percent of patients with the histological finding of cell differentiation were recurrence-free at 5 years. A marginally significant increase in the 5-year survival rate was also seen in association with differentiation. Only 34% of the patients whose tumor exhibited necrosis were alive at 5 years.

There was no statistically significant difference in 5-year survival for children under 3 years of age or for the group of children aged 5 years or under. However, a significantly larger fraction (72%) of the group aged 5 years or under had a recurrence-free period of 5 years or more. Other factors including sex, extent of surgical resection, Chang tumor stage, posterior fossa radiation dose, and adjuvant chemotherapy did not influence prognosis.
Neurosurgical use of human dura mater sterilized by gamma rays and stored in alcohol: long-term results
Authors: Cantore Giampaolo , Guidetti Beniamino , Delfini Roberto
Published: May 2009

✓ Surgical experience with grafts of human dura mater sterilized by gamma rays and preserved in alcohol is reported in 804 cases. The method of graft preparation is a simple, cheap, and practical technique for making available a plentiful quantity of large and small pieces of dura to use for plastic reconstruction in everyday neurosurgical practice. Annual inspection for sterility and immunogenicity over an 18-year period indicates that this system of preservation is valid for an unlimited period of time.
Transient suppression of event-related evoked potentials produced by mild head injury in the cat
Authors: DeSalles Antonio A. F. , Newlon Pauline G. , Katayama Yoichi , Dixon C. Edward , Becker Donald P. , Stonnington Henry H. , Hayes Ronald L.
Published: May 2009

✓ Studies in humans have shown that sensory stimuli, presented in the context of certain tasks, can elicit a late positive component (LPC), namely P300, in the scalp-recorded evoked potential believed to reflect neural activity related to attentional processes. A similar LPC has been reported in cats and monkeys. In this study, the LPC of the auditory evoked potential (AEP) in the cat was used to detect impairment in attention to a relevant stimulus after low levels of cerebral concussion produced by a fluid percussion device. A hollow screw (for fluid percussion) and stainless steel screws (for AEP recording) were surgically placed in the skull. After recovery from surgery, animals were trained in the paradigm to obtain an LPC. Pupillary dilation was conditioned to tones. A random sequence of two discriminable tones was presented. The lower tone had a probability of 0.1 and was followed by a tail shock (tone-shock). After 400 to 1000 tone-shock presentations, animals attended to the lower tone stimulus as inferred by selective pupillary dilation. In the AEP an early positive component at 50 to 120 msec related to an alerting response was enhanced, and an LPC at 250 to 450 msec appeared in response to the paired tone-shock. Animals were then subjected to cerebral concussion. Complete recovery of normal reflexes, motor coordination, and orienting response was seen within 2 hours after injury. The LPC was suppressed for a period of at least 3 days, suggesting that low magnitudes of brain injury can disrupt higher-order neural activities. This disruption can persist despite recovery of other neurological functions.
Treatment of experimental focal cerebral ischemia with mannitol
Authors: Meyer Fredric B. , Anderson Robert E. , Sundt Thoralf M. , Yaksh Tony L.
Published: May 2009

✓ Intracellular brain pH, cortical blood flow (CBF), and electrocorticograms were recorded in regions of severe and moderate ischemia in 10 control rabbits and 10 rabbits given mannitol, 1 gm/kg, after occlusion of a major branch of the middle cerebral artery. Pooling the data from all 20 animals, preocclusion CBF was 46.4 ±3.6 ml/100 gm/min and intracellular brain pH was 7.01 ± 0.04 (means ± standard error of the means). Although mannitol administration mildly improved CBF in regions of severe ischemia, this increase was not sufficient to prevent metabolic deterioration as assessed by brain pH. However, in regions of moderate ischemia, CBF improved significantly with mannitol and the gradual decline in brain pH observed in control animals was prevented. For example, in the treated moderate ischemia sites 4-hour postocclusion CBF and pH values were 31.8 ml/100 gm/min and 6.89 ± 0.09, respectively, as compared to control values of 14.3 ml/ 100 gm/min and 6.75 ± 0.06. These results suggest that mannitol may be of benefit in stabilizing regions of moderate, but not severe, ischemia after vessel occlusion.