bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of timing of clot removal on chronic vasospasm in a primate model
Authors: Handa Yuji , Weir Bryce K. A. , Nosko Michael , Mosewich Russ , Tsuji Tsutomu , Grace Michael
Published: May 2009

✓ The effect of complete clot removal at times from 48 to 96 hours after subarachnoid hemorrhage (SAH) on the development of chronic cerebral vasospasm was evaluated to determine whether there is a critical point after which clot removal is ineffective in preventing vasospasm. Thirty cynomolgus monkeys were randomized to one of five groups: sham-operated group, clot removal at 48 hours after SAH (48-hour group), clot removal at 72 hours after SAH (72-hour group), clot removal at 96 hours after SAH (96-hour group), and clot placement only (clot group). Standard microsurgical techniques were used to dissect bilaterally the major cerebral arteries free of arachnoid. An autologous blood clot averaging 4.2 gm was placed around the vessels in the subarachnoid space of the monkeys in the 48-hour, 72-hour, 96-hour, and clot groups. Physiological saline was instilled into the subarachnoid space of the sham-operated animals. Animals in the clot-removal groups underwent surgical clot removal at the determined times for each group. Two animals in each of the sham-operated and clot groups were subjected to reoperation at each of 48, 72, and 96 hours after SAH. The incisions were reopened and then simply reclosed. Neurological status, angiographic cerebral vessel caliber, and physiological status were evaluated before and 7 days after SAH induction. There were no significant neurological deficits in the sham-operated, 48-hour, or 72-hour groups. Two animals in each of the 96-hour and clot groups showed deterioration in level of consciousness developing on Day 4 or 5 after SAH induction. All the major cerebral arteries of the animals in the clot and 96-hour groups showed significant vasospasm (p < 0.01) on Day 7. Animals in the 72-hour group had significant vasospasm (p < 0.05) of the internal carotid and middle cerebral arteries but not the anterior cerebral arteries. There was no significant vasospasm (p > 0.05) in any of the cerebral arteries in the 48-hour group. Severity of vasospasm paralleled the duration of contact between the blood clot and the cerebral vessels. Evacuation of the subarachnoid hematoma later than 48 hours after SAH resulted in no significant reduction in the degree of chronic cerebral vasospasm. It is suggested that clot removal at early operation is likely to be useful only if it is performed within 48 hours of SAH.
Further modifications for the Frazier suction device
Authors: Davidson Robin I. , Rodgers Cyril
Published: May 2009

✓ Two modifications of the Frazier suction device are described: a removable distal retractor that is clipped to a modified suction tip and a coupling device that decreases counter-rotational torque.
AANS Presidential Address: The tradition of Harvey Cushing commemorated by a stamp in the Great American stamp series
Authors: Ojemann Robert G.
Published: May 2009

✓ With the announcement that Harvey Cushing is to be honored by a United States postage stamp in the Great American stamp series, the qualities that this remarkable man possessed are reviewed — artist, author, bibliophile, scientist, soldier, physician, and teacher. The events that led to Cushing becoming a neurosurgeon are summarized. The recognition by the United States Postal Service of physicians and others who have appeared on stamps that had some relationship to Cushing's activities is discussed. Based on the tradition of Harvey Cushing, eight guidelines are presented.
Results of lumbar discectomy in the pediatric patient
Authors: Ebersold Michael J. , Quast Lynn M. , Bianco Anthony J.
Published: May 2009

✓ To determine the results of lumbar discectomy in pediatric patients, a review was conducted of the medical records of 74 consecutive patients (40 males and 34 females) younger than 17 years who underwent lumbar disc surgery between 1950 and 1983. During this period, only 3% of patients younger than 17 years who presented with the chief complaint of low-back pain eventually had lumbar disc operation. In 43 patients it was thought that an injury had precipitated the symptoms. Thirty-seven patients had a nerve deficit at the time of initial evaluation. Water-soluble contrast myelography with repeated postmyelographic computerized tomography is currently used to confirm the diagnosis. The disc operations were performed at the L4–5 level in 47% of patients, the L5–S1 level in 45%, the L3–4 and L4–5 level in 4%, and the L4–5 and L5–S1 level in 4%. Fourteen of the 74 patient underwent spinal fusion with their first operation. At 9 months postoperatively, 95% had good or excellent results. During an extended follow-up period of up to 34 years, 16 of the patients with early successful results required further back procedures. After all medical and surgical treatment in this group of patients, the results were excellent in 57%, good in 38%, and poor in only 4%.
Neurobehavioral functioning and magnetic resonance imaging findings in young boxers
Authors: Levin Harvey S. , Lippold Stephen C. , Goldman Arnold , Handel Stanley , High Walter M. , Eisenberg Howard M. , Zelitt David
Published: May 2009

✓ In a prospective investigation of neurobehavioral functioning in young boxers, 13 pugilists and 13 matched control subjects underwent tests of attention, information-processing rate, memory, and visuomotor coordination and speed. The results disclosed more proficient verbal learning in the control subjects, whereas delayed recall and other measurements of memory did not differ between the two groups. Reaction time was faster in the boxers than in the control subjects, but no other differences were significant. Ten subjects in each group were retested 6 months later and exhibited improvement in their neuropsychological performance as compared to baseline measurements. However, there were no differences in scores between the boxers and the control subjects at the follow-up examination or in the magnitude of improvement from baseline values. Magnetic resonance imaging, which was performed in nine of the boxers, disclosed normal findings.
Magnetic resonance images of chronic subdural hematomas
Authors: Hosoda Kohkichi , Tamaki Norihiko , Masumura Michio , Matsumoto Satoshi , Maeda Fumio
Published: May 2009

✓ Magnetic resonance imaging (MRI) and computerized tomography (CT) scans of 18 patients with 20 chronic subdural hematomas were compared. In many ways, MRI was superior to CT for demonstrating the hematomas. In general, chronic subdural hematomas were hyperintense on both T1- and T2-weighted MRI. The T1 values of chronic subdural hematomas were significantly shorter than gray matter values and significantly longer than white matter values. The T2 values were significantly longer than both gray matter and white matter values. These findings were consistent with previous reports. However, six hematomas (30%) were iso- or hypointense on T1-weighted images. Possible mechanisms responsible for the difference in intensity of chronic subdural hematoma on MRI are discussed, and the important role of methemoglobin formation is emphasized.
Quantitative study of microvessel ultrastructure in human peritumoral brain tissue
Authors: Stewart Patricia A. , Hayakawa Kay , Farrell Catherine L. , Del Maestro Rolando F.
Published: May 2009

✓ The form and function of blood vessels are determined by the cells that constitute their microenvironment. Brain tissue around tumors contains varying numbers of tumor cells that could influence local capillaries to lose their blood-brain barrier (BBB), as they do in the tumor itself. Microvascular permeability cannot be measured directly in humans but can be inferred from a knowledge of vessel ultrastructure. The authors have examined the vascular ultrastructure associated with the BBB in human peritumoral brain tissue for evidence of BBB compromise and to correlate BBB features with the cellular components of the vessel microenvironment.

Light microscopic examination of brain tissue samples in patients with primary brain tumors showed that the tissue lying beyond the visible edge of the tumor ranged from essentially normal to grossly infiltrated with tumor cells. Although some of the vessels were structurally normal, the microvessels as a group had elongated junctional clefts (unfused regions) and an increase in the density of endothelial vesicles. Furthermore, the cleft index (the percentage of the junctional profile that is unfused) varied directly with the local cell density. A subpopulation of vessels enveloped by a layer of tumor cells was grossly abnormal. However, vessels that were not immediately invested by tumor cells also showed some abnormalities. It is concluded that tumor cells infiltrating peritumoral brain tissue cause blood vessels to take on some of the structural characteristics of leaky vessels. Since direct contact is not required, and since the degree of abnormality correlates with the number of tumor cells in the environment, the authors suggest that this inductive influence is exerted over a distance and is dependent on the concentration of the inducing factors.
Experimental chronic subdural hematoma in mice
Authors: Aikawa Hisashi , Suzuki Kinuko
Published: May 2009

✓ A new experimental model of chronic subdural hematoma in mice is described. A single intraperitoneal injection of 6-aminonicotinamide (25 mg/kg body weight) on the 5th postnatal day induced hydrocephalus in mice with almost 100% success. Approximately 60% of the mice spontaneously developed intracranial hemorrhage 20 days after the injection. About 1 week after the hemorrhage, a lens-shaped or spherical subdural hematoma was observed, accompanied by marked dilatation of the lateral ventricles and intraventricular hemorrhage. Histological examination revealed that the hematoma contained well-organized outer and inner membranes. Fresh hemorrhage surrounded by many hemosiderin-laden macrophages was seen at the margin of the hematoma adjacent to the organizing outer membrane, in which many fibroblasts and blood vessels were noted. The inner membrane of the hematoma was made up of several tiers of flattened cells with thin-walled blood vessels. The gross morphology and histology of these hematomas closely resembled those of human chronic subdural hematoma.
Uniformity of intracarotid drug distribution with diastole-phased pulsed infusion
Authors: Shook Daniel R. , Beaudet Lisa M. , Doppman John L.
Published: May 2009

✓ Drug streaming has been implicated in the development of focal necrotic lesions in perfused tissues following intracarotid chemotherapy of brain tumors at low infusion rates. The narrow infusate path characteristic of streaming within laminar blood flow is not observed at high infusion rates such as are typical in contrast injection for angiography. By periodically pulsing the infusate at a high rate, the mechanisms of rapid mixing can be exploited while retaining the practicality of low average infusion rates. This in vitro study demonstrates the effects of the pulse-controlling parameters and the catheter characteristics and placement on mixing effectiveness. An internal carotid artery model including eight cerebral branches was infused with dye through various indwelling catheters, and individual branch effluents were collected and analyzed spectrophotometrically for dye concentration. While catheter placement dominates the factors that control infusate distribution, judicious selection of the pulse parameters can alleviate that dependence. A primary advantage is gained by phasing the pulse to occur during that period of the cardiac cycle when the blood flow is lowest at the injection site. The data clearly showed that diastole-phased pulsed infusions are highly effective in producing a uniform infusate distribution at low average infusion rates.
Pituicytoma (pilocytic astrocytoma)
Authors: Rossi Marco L. , Bevan John S. , Esiri Margaret M. , Hughes John T. , Adams Christopher B. T.
Published: May 2009

✓ Tumors of the posterior pituitary are rare and the previous nomenclature has been confusing. A 40-year-old man presented with visual failure and disconnection hyperprolactinemia (830 mU/liter) due to a large invasive pituitary tumor shown to be a pituicytoma (pilocytic astrocytoma). Its astrocytic nature was confirmed by positive immunostaining for glial fibrillary acidic protein and the finding of cytoplasmic filaments on electron microscopy. This case report contains the pathological description of a pituicytoma and illustrates that a non-adenomatous pituitary lesion may masquerade as a pituitary adenoma. Large pituitary lesions associated with serum prolactin concentrations of less than 3000 mU/liter require early surgical biopsy.
Symptomatic intracranial pneumatocele from mastoid sinus of spontaneous origin
Authors: Stavas Joseph , McGeachie Robert E. , Turner Dennis A. , Nelson Mary Jo
Published: May 2009

✓ A case of a large intracranial pneumatocele arising from mastoid air cells is reported. The patient became symptomatic after multiple coughing spells and required craniotomy for repair of the dural hiatus. The possible etiology of such a large spontaneous pneumatocele is discussed in the context of a review of the pertinent literature.
Spinal arteriovenous malformations: a comparison of dural arteriovenous fistulas and intradural AVM's in 81 patients
Authors: Rosenblum Bruce , Oldfield Edward H. , Doppman John L. , Di Chiro Giovanni
Published: May 2009

✓ The medical records and arteriograms of 81 patients with spinal arteriovenous malformations (AVM's) were reviewed, and the vascular lesions were classified as dural arteriovenous (AV) fistulas or intradural AVM's. Intradural AVM's were further classified as intramedullary AVM's (juvenile and glomus types) and direct AV fistulas, which were extramedullary or intramedullary in location. Dural AV fistulas were defined as being supplied by a dural artery and draining into spinal veins via an AV shunt in the intervertebral foramen. Intramedullary AVM's were defined as having the AV shunt contained at least partially within the cord or pia and receiving arterial supply by medullary arteries.

Of the 81 patients, 27 (33%) had dural AV fistulas and 54 (67%) had intradural AVM's. Several dissimilarities in clinical and radiographic findings of the two subgroups were evident. The patients with intramedullary AVM's were younger; the age at onset of symptoms averaged 27 years compared to 49 years for dural AV fistulas. The most common initial symptom associated with dural AV fistulas was steadily progressive paresis, whereas hemorrhage was the most common presenting symptom in cases of intramedullary lesions. No patients with dural AV fistulas had subarachnoid hemorrhage. Activity exacerbated symptoms more frequently in patients with dural lesions. Associated vascular anomalies occurred only in cases of intradural AVM's. In 96% of the dural lesions the AV nidus was in the low thoracic or lumbar region; in only 15% did the intercostal or lumbar arteries supplying the AVM also provide a medullary artery which supplied the spinal cord. In contrast, most intradural AVM's (84%) were in the cervical or thoracic segments of the spinal cord and all of them were supplied by medullary arteries. Transit of contrast medium through the intradural AVM's was rapid in 80% of cases, suggesting high-flow lesions. Forty-four percent of the patients with AVM's of the spinal cord had associated saccular arterial or venous spinal aneurysms. No dural AV fistulas displayed these characteristics. A good outcome occurred in 88% of patients with dural AV fistulas after nidus obliteration, while 49% of patients with intramedullary AVM's did well after surgery or embolization.

These findings suggest that dural and intradural AVM's differ in etiology (acquired vs. congenital) and that they have different pathophysiology, radiographic findings, clinical presentation, and response to treatment.
Growth rate of human pituitary adenomas
Authors: Landolt Alex M. , Shibata Taichiro , Kleihues Paul
Published: May 2009

✓ The immunohistological detection of a proliferation-associated nuclear antigen by the monoclonal antibody Ki-67 allows the determination of the growth fraction in human cell populations. In this study, biopsy specimens of 31 pituitary adenomas representing all major endocrine types were examined. All adenomas contained proliferating cells and the percentage of nuclei that were immunoreactive to Ki-67 ranged from 0.1% to 3.7%. Low values (0.1% to 1.0%) were present in 11 endocrine-inactive adenomas and higher values (1.1% to 1.5%) were found in six acromegalic patients. The percentages of Ki-67-positive cells in 12 prolactinomas and two adenomas from patients with Cushing's disease covered the entire range (0.1% to 3.7%). Preoperative bromocriptine treatment of prolactinomas did not influence Ki-67 expression. Invasive adenomas, as determined by preoperative computerized tomography, surgical observation, and histological examination of the sella dura demonstrated significantly higher Ki-67 values (average 1.15%) than noninvasive adenomas (average 0.60%). Determination of the incidence of proliferating cells by Ki-67 immunoreactivity represents a new tool for intraoperative quantitative assessment of tumor growth characteristics and may aid in the planning of adjuvant therapy and estimation of prognosis.
A comparison of intraparenchymatous and intraventricular pressure recording in clinical practice
Authors: Sundbärg Göran , Nordström Carl-Henrik , Messeter Kenneth , Söderström Sven
Published: May 2009

✓ A comparison of intraventricular pressure (IVP) and intraparenchymatous pressure was performed in 11 patients with severe traumatic brain lesions. Intraparenchymatous pressure was measured with a Honeywell microtransducer placed intracerebrally. Before the microtransducer was used in clinical practice, basic data on drift and temperature sensitivity were tested in experiments in vitro. Under clinical conditions the correspondence between the measured IVP and intraparenchymatous pressures appeared to be better than previously reported for different devices for epidural or subdural pressure recording. It is concluded that intraparenchymatous pressure monitoring is reliable in clinical practice and that such measurements are valuable in patients with compressed and/or distorted ventricles that preclude possibilities for IVP recording.
Efficacy of irradiation for incompletely excised acoustic neurilemomas
Authors: Wallner Kent E. , Sheline Glenn E. , Pitts Lawrence H. , Wara William M. , Davis Richard L. , Boldrey Edwin B.
Published: May 2009

✓ The records of 124 patients treated for acoustic neurilemoma at the University of California, San Francisco, from 1945 through 1983 were reviewed. Patients were classified by the extent of surgical resection: total, nearly total (90% to 99% resection), subtotal (< 90% resection), or biopsy. Thirty-one patients received irradiation as part of their primary treatment. Total resection of tumor, without irradiation, was associated with a 3% chance of local recurrence. One of 15 patients who had nearly total resection of their tumor and did not receive postoperative irradiation suffered a recurrence, compared with neither of the two patients who received postoperative irradiation (> 45 Gy) following nearly total resection. Postoperative irradiation (> 45 Gy) decreased the recurrence rate after subtotal resection from 46% (six of 13 cases without irradiation) to 6% (one of 17 cases: p = 0.01). All three patients treated by biopsy alone received postoperative irradiation (> 45 Gy), and none had a recurrence. Six patients were treated with preoperative irradiation because of excessive tumor vascularity; four are without evidence of disease 12 to 23 years later. Only three of seven patients treated with irradiation for tumor recurrence after surgical resection survived. It is concluded that postoperative irradiation significantly decreased the chance for local tumor progression following subtotal resection of acoustic neurilemoma, and that postoperative irradiation may be effective therapy following treatment by biopsy. Patients with total or nearly total resection appeared not to benefit from postoperative irradiation.
Glioblastoma developing at the site of a cerebellar medulloblastoma treated 6 years earlier
Authors: Schmidbauer Manfred , Budka Herbert , Bruckner Robert , Vorkapic Peter
Published: May 2009

✓ The authors report the highly unusual development of a glioblastoma multiforme at the site of excision of a medulloblastoma 6 years earlier. The patient was operated on for a cerebellar medulloblastoma at the age of 13 years. Postoperative treatment included irradiation and chemotherapy. Six years later, a glioblastoma multiforme was found at the original site of the medulloblastoma. Intensive multimodality treatment is considered the likely cause for the later tumor development.
Hemodynamic analysis of associated extracranial atraumatic vertebral artery aneurysm and arteriovenous fistula
Authors: Rosenblum Bruce , Rifkinson-Mann Stephanie , Sacher Michael , Gennuso Rosemaria , Rothman Allen
Published: May 2009

✓ A case of atraumatic arteriovenous (AV) fistula of the extracranial vertebral artery associated with an atraumatic aneurysm of the contralateral extracranial vertebral artery is reported. The fistulous lesion was excised after distal and proximal ligation of the vessel. Subsequently, the contralateral aneurysm underwent spontaneous dissolution. Seven cases of extracranial vertebral AV fistulae associated with ipsilateral vertebral artery aneurysms (four traumatic and three as part of vascular dysplastic syndromes) have been reported previously.
Cavernous angiomas of the spinal cord
Authors: Cosgrove G. Rees , Bertrand Gilles , Fontaine Suzanne , Robitaille Yves , Melanson Denis
Published: May 2009

✓ Five cases of histologically verified cavernous angiomas of the spinal cord are reported. Acute lower-extremity sensory disturbance was the initial symptom in four patients, and one presented with weakness of the hand. Progressive neurological deficit occurred in all patients, but the clinical course and outcome were extremely variable. Myelography revealed an intramedullary lesion in two cases but was completely normal in three; magnetic resonance imaging was diagnostic in these patients. Subtotal removal was accomplished in two cases, and myelotomy and biopsy were carried out in three. Four of the cavernous angiomas were located in the cervicothoracic region, whereas one was found in the thoracolumbar cord. All of the patients exhibited characteristic gross and microscopic features as well as hemosiderin-laden macrophages indicating remote hemorrhage. The diagnostic, therapeutic, and prognostic implications of this rare condition are discussed.
Gliomas of the optic nerve or chiasm
Authors: Alvord Ellsworth C. , Lofton Steven
Published: May 2009

✓ A review of the literature revealed 623 cases of optic gliomas with sufficient information to permit actuarial (life-table) analysis concerning the prognosis of this disease by the patients' age, tumor site, treatment, and presence of concomitant neurofibromatosis or extension into the hypothalamus or ventricle. All of these factors are important. The development of mathematical models led to the conclusion that these tumors, generally regarded histologically as low-grade astrocytomas, actually have a very wide but continuous range of growth rates. Some grow rapidly enough to be explained by simple exponential doubling at a constant rate, but most behave as though their growth decelerates. Decelerating growth rates make comparisons of various groups of patients difficult. No support is found for the classical hypothesis that some may be hamartomas.

Inadequately treated gliomas of the optic nerve or chiasm bear about the same poor prognosis. However, tumors of the optic nerve (intracranial as well as intraorbital) have an excellent prognosis following complete surgical excision and only a slightly poorer prognosis following irradiation. About 5% of optic nerve gliomas recur in the chiasm following “complete” intraorbital excision. Patients with neurofibromatosis have about twice the recurrence rate following complete excision of an intraorbital glioma. Optic chiasmal gliomas appear to respond to irradiation with doses above 4500 rads. Patients with neurofibromatosis have about the same prognosis as patients without neurofibromatosis following irradiation of a chiasmal glioma.
The effect of fetal hypothalamus grafts on weight gain resulting from lesions of the ventromedial hypothalamus
Authors: Erickson Robert K. , Brown Frederick D. , Schaible Keith L. , Wollmann Robert L.
Published: May 2009

✓ Bilateral ventromedial hypothalamic lesions in female adult rats which resulted in hyperphagia and rapid weight gain were followed by placement of fetal brain tissue in the anterior third ventricle. The treatment group received fetal hypothalamus grafts, and fetal cortical tissue of identical age was grafted into the control group. A significant reduction in average daily weight gain was noted from 4 to 12 weeks following transplantation in the treatment group. At 12 weeks posttransplantation, the animals were sacrificed for histological analysis. Examination of the hypothalamus grafts revealed neurons, ependymal clusters, and axonal processes which appeared to infiltrate the surrounding hypothalamic parenchyma.
Evaluation of acellular and cellular nerve grafts in repair of rat peripheral nerve
Authors: Gulati Adarsh K.
Published: May 2009

✓ Nerve grafts composed of basal lamina scaffolds and lacking viable Schwann cells have recently been shown to be effective in supporting axonal regeneration. As only short grafts were used in those studies, the present investigation was conducted to evaluate the ability of long acellular basal lamina nerve grafts and equivalent cellular grafts to support axonal regeneration for nerve gap repair. Cellular grafts consisted of nerve segments that had degenerated in situ for 4 weeks. Acellular grafting material consisted of similar segments that were repeatedly frozen and thawed to kill all cells prior to grafting. The results show that host axons can regenerate through the entire 4-cm length of cellular grafts but not through acellular basal lamina grafts. However, in the acellular grafts numerous axons were seen in the proximal 2-cm region. It is concluded that basal lamina grafts possess limited ability to support axonal regeneration. As in cellular grafts, viable Schwann cells appear to be important for regeneration to occur over longer distances.
Odontoid process fracture osteosynthesis with a direct screw fixation technique in nine consecutive cases
Authors: Borne Guy M. , Bedou Gerard L. , Pinaudeau Magloire , Cristino Gerardo , Hussein Ahmad
Published: May 2009

✓ The authors present their experience with surgical treatment of odontoid process fractures using a direct screw fixation technique via an anterolateral retropharyngeal approach. Nine consecutive patients have been operated on with this technique. There were two deaths unrelated to the surgery, and anatomical union with conservation of the craniospinal hinge mobility was achieved in the remaining seven patients. The direct screw fixation technique appears feasible, efficient, and logical.
Use of etomidate, temporary arterial occlusion, and intraoperative angiography in surgical treatment of large and giant cerebral aneurysms
Authors: Batjer H. Hunt , Frankfurt Alan I. , Purdy Phillip D. , Smith Shirley S. , Samson Duke S.
Published: May 2009

✓ The operative management of large and giant aneurysms is complicated by their typically atheromatous and thick walls, frequent intramural thrombosis with calcification, and broad-based necks that often incorporate perforating and other vital vessels. Not infrequently, it is necessary to at least focally arrest the intracranial circulation and open or excise these aneurysms to facilitate vascular reconstruction. This maneuver, in patients whose disease processes have destroyed autoregulatory function or who have inadequate sources of anatomical collateral supply, may cause the threshold for permanent ischemic injury to be exceeded. The authors have recently treated 14 such patients while under electroencephalographic monitoring to document electrical burst suppression induced by the administration of etomidate, followed by temporary clipping to permit vascular repair and intraoperative angiography to document patency of parent arteries. Up to 60 minutes of internal carotid artery occlusion, 35 minutes of middle cerebral artery occlusion, 19 minutes of upper basilar artery occlusion, and 4½ minutes of lower basilar artery occlusion have been well tolerated using this protocol. In such situations, etomidate may be effective in protecting the cerebral circulation without the detrimental cardiotoxicity observed with protective doses of barbiturates.
Physiological support and monitoring of critically ill patients during magnetic resonance imaging
Authors: Barnett Gene H. , Ropper Allan H. , Johnson Keith A.
Published: May 2009

✓ Magnetic resonance (MR) imaging has been largely restricted to patients who are neurologically and hemodynamically stable. The strong magnetic field and radiofrequency transmissions involved in acquiring images are potential sources of interference with monitoring equipment. A method of support and physiological monitoring of critically ill neurosurgical and neurological patients during MR imaging using a 0.6-tesla MR system is reported. This technique has not caused degradation of the MR image due to electrical interference. Adequate preparation and precautions allow many critically ill neurosurgical and neurological patients to safely undergo MR imaging.
The role of vasopressin in acute cerebral vasospasm
Authors: Delgado Tia Juana , Arbab Mohammed Abdul-Rahman , Warberg Jorgen , Svendgaard Niels-Aage
Published: May 2009

✓ An experimental model of subarachnoid hemorrhage (SAH) in the Sprague-Dawley rat induces angiographically demonstrable, reproducible biphasic vasospasm of the vertebrobasilar system. The acute vasospasm is maximum at 10 minutes and the maximum late vasospasm occurs 2 days after the SAH. Brattleboro rats, which are deficient in arginine vasopressin (AVP), do not have acute vasospasm after SAH but exhibit a degree of late vasospasm that is not significantly different from that seen in Sprague-Dawley rats. Cisternal injection of AVP induced acute vasospasm in Sprague-Dawley rats with a duration similar to that seen after cisternal blood injection; however, at 2 days, the vessel diameter was normal. Intravenous AVP antagonist or intracisternal AVP antiserum administered prior to the SAH prevented the development of acute vasospasm without affecting the late phase. The data suggest that an increased release of AVP in the cerebrospinal fluid is involved in the development of acute cerebral vasospasm.
Vein of Galen aneurysm associated with dural AVM and straight sinus thrombosis
Authors: Mayberg Marc R. , Zimmerman Christian
Published: May 2009

✓ A 64-year-old man presented with symptoms of obstructive hydrocephalus secondary to a vein of Galen aneurysm associated with a dural arteriovenous malformation and straight sinus thrombosis. The interrelationship of these lesions and their clinical and radiological features are discussed. It is proposed that in this case sinus thrombosis was the primary event in the subsequent development of the other lesions.
Enterogenous cyst in the cervical spinal canal
Authors: Miyagi Kouichi , Mukawa Jiro , Mekaru Susumu , Ishikawa Yasunari , Kinjo Toshihiko , Nakasone Susumu
Published: May 2009

✓ The case of an 11-year-old Japanese girl with an intradural and extramedullary enterogenous cyst is presented. A mass giving a low-intensity signal in comparison with the spinal cord was demonstrated on magnetic resonance imaging. Histologically, the diagnosis was confirmed on specimens stained with periodic acid-Schiff, alcian blue, mucicarmine, and immunohistochemical staining of carcinoembryonic antigen, and by electron microscopy.
Nerve-cell grafting in Parkinson's disease
Authors: Sladek John R. , Gash Don Marshall
Published: May 2009

✓ The successful utilization of fetal nerve-cell grafts as therapeutic tools in animal models of neurodegenerative disease has prompted the first clinical attempts in parkinsonian patients in at least three countries. The extensive scientific data in rodents coupled with the first successful fetal neural grafts in monkeys with experimental parkinsonism suggest that consideration might now be given to clinical applications. Attention is also directed to the various types of donor cells that might be utilized in clinical trials for the treatment of parkinsonism, including potential benefits, risks, and limitations associated with each type of donor material. This review highlights major developments in this field as they relate to basic principles of neural grafting and discusses potential applications in humans.
The natural history of unruptured intracranial arteriovenous malformations
Authors: Brown Robert D. , Wiebers David O. , Forbes Glenn , O'Fallon W. Michael , Piepgras David G. , Marsh W. Richard , Maciunas Robert J.
Published: May 2009

✓ The authors conducted a long-term follow-up study of 168 patients to define the natural history of clinically unruptured intracranial arteriovenous malformations (AVM's). Charts of patients seen at the Mayo Clinic between 1974 and 1985 were reviewed. Follow-up information was obtained on 166 patients until death, surgery, or other intervention, or for at least 4 years after diagnosis (mean follow-up time 8.2 years). All available cerebral arteriograms and computerized tomography scans of the head were reviewed. Intracranial hemorrhage occurred in 31 patients (18%), due to AVM rupture in 29 and secondary to AVM or aneurysm rupture in two. The mean risk of hemorrhage was 2.2% per year, and the observed annual rates of hemorrhage increased over time. The risk of death from rupture was 29%, and 23% of survivors had significant long-term morbidity. The size of the AVM and the presence of treated or untreated hypertension were of no value in predicting rupture.
Symptomatic low intracranial pressure in shunted hydrocephalus
Authors: Foltz Eldon L. , Blanks Jeff P.
Published: May 2009

✓ Fourteen patients with ventricular cerebrospinal fluid shunts in place for chronic hydrocephalus presented with a history and neurological deficits usually associated with high intracranial pressure (ICP) caused by an obstructed shunt system. However, the symptoms were characteristically present when the patient was upright and active, and were usually relieved by lying down. The symptoms of intermittent headache, nausea, emesis, lethargy, and diplopia were associated with paresis of upward gaze or minimal strabismus. Measurement of ICP showed unexpected dramatically low levels with a marked drop in pressure when the patient was in the upright position, whereas ICP was near normal when the patient was supine. The low ICP was corrected by insertion of a high-pressure Flo-Control valve into the shunt system already in place. Postoperatively, the immediate clinical improvement and more normal ICP measurements were striking.

The important clinical finding in this group of patients was the presence of disabling symptoms which occurred when the patients were up and active and which were relieved by lying down. Measurements of ICP with the patient in the supine and then in the upright position were critical in establishing an accurate diagnosis of symptomatic low ICP in these hydrocephalic patients with indwelling shunts. With the patient in the Trendelenburg position, ICP showed a marked increase, as expected; in some patients this position was prescribed as treatment for several days before surgery.
Cerebral blood flow, vasoreactivity, and oxygen consumption during barbiturate therapy in severe traumatic brain lesions
Authors: Nordström Carl-Henrik , Messeter Kenneth , Sundbärg Göran , Schalén Wilhelm , Werner Mats , Ryding Erik
Published: May 2009

✓ Mean hemispheric cerebral blood flow (CBF) and intracranial pressure (ICP) were measured in 19 severely head-injured patients treated with barbiturate coma. The CBF was calculated from the clearance of tracer substance monitored by extracranial scintillation detectors after intravenous administration of xenon-133. In 11 of the patients cerebral arteriovenous oxygen differences were measured simultaneously. In all patients the effects of pronounced hyperventilation were recorded prior to initiation of barbiturate treatment. A normal CBF response to hyperventilation (ΔCBF/ΔPaCO2 ≥ 1) was obtained in eight patients. In these patients induction of barbiturate coma was accompanied by physiological decreases in CBF and in the calculated cerebral metabolic rate of oxygen (CMRO2); they also exhibited a rapid and lasting decrease in ICP. A decreased or an abolished CO2 reactivity was recorded (ΔCBF/ΔPaCO2 < 1) in 11 patients. In 10 of these 11 patients the physiological decreases in CBF and CMRO2 were not obtained during barbiturate treatment and the decrease in ICP was transitory. This study demonstrates a correlation between cerebral vasoreactivity, physiological effects of barbiturate therapy, and clinical outcome.
Clinical, radiological, and pathological spectrum of angiographically occult intracranial vascular malformations
Authors: Lobato Ramiro D. , Perez Carlos , Rivas Juan J. , Cordobes Francisco
Published: May 2009

✓ The clinical, radiological, and histopathological features of 21 cases of angiographically occult intracranial vascular malformations (AOIVM's) are analyzed, and a review of 241 additional appropriately documented, histologically verified cases collected from the literature is presented. In all, there were 115 (43.8%) arteriovenous malformations, 82 (31.2%) cavernous angiomas, 26 (9.9%) venous angiomas, 10 (3.8%) cases of capillary telangiectasis, and 29 (11%) mixed or unclassified angiomas. The result of the analysis shows that there are no essential differences in the patterns of clinical presentation, the computerized tomography (CT) appearance, or the surgical prognosis among these pathological types of vascular malformations. Certain histological features common to all AOIVM's (such as the small caliber, the more or less complete thrombosis of the malformed vessels, and the changes induced in the surrounding brain tissue by repeated microhemorrhages) seem to determine the biological behavior of the anomaly rather than the predominant type of vessel involved. Thus, subdivision of AOIVM's into the four classical pathological types has little practical value.

Most AOIVM's are visualized by the CT scan and show a rather typical appearance. Surgical removal, which prevents rebleeding and ameliorates or suppresses seizure activity, is usually easy to perform and represents the treatment of choice for patients with clinically symptomatic AOIVM's.
Intradural arachnoid cysts of the spinal canal associated with intramedullary cysts
Authors: Andrews Brian T. , Weinstein Philip R. , Rosenblum Mark L. , Barbaro Nicholas M.
Published: May 2009

✓ Five patients had intradural arachnoid cysts of the thoracic spinal canal associated with syringomyelia or posttraumatic intramedullary spinal cord cysts. Three cases were diagnosed 6 to 18 years after spinal surgery and two 14 to 17 years after spinal cord trauma. In each case, delayed progression of symptoms led to the identification of the lesions. The diagnosis was assisted by the use of myelography and delayed computerized tomography scanning in two cases and by magnetic resonance imaging in all five. In each case, the arachnoid cyst appeared to compress the spinal cord or nerve roots; in three cases, the syrinx cavities appeared to exert a significant mass effect. In the two trauma-related cases, the intramedullary cysts were small and may have represented areas of cystic myelomalacia. In four cases, intraoperative real-time ultrasonography helped to localize the arachnoid and intramedullary cavities. All five patients were treated by fenestration of the arachnoid cyst; additional peritoneal shunting of the cyst was performed in one case and of the intramedullary cavity in three. In one patient, the two lesions appeared to have a balancing effect; after drainage of the arachnoid cyst, the syrinx cavity expanded and had to be treated separately. The neurological deficits were reduced in four patients and stabilized in one. Intradural arachnoid cysts and intramedullary cysts may occur together as a late complication of spinal surgery or spinal cord trauma, and either or both lesions may cause delayed neurological deterioration.
Management of prolactinomas associated with very high serum prolactin levels
Authors: Barrow Daniel L. , Mizuno Junichi , Tindall George T.
Published: May 2009

✓ The authors have reviewed the results of transsphenoidal microsurgical management in 69 patients with prolactin-secreting pituitary adenomas who had preoperative serum prolactin levels over 200 ng/ml. The patients were divided into three groups based on their preoperative serum prolactin levels: over 200 to 500 ng/ml (Group A); over 500 to 1000 ng/ml (Group B); and over 1000 ng/ml (Group C). The percentage of successful treatment (“control rate”) was 68%, 30%, and 14%, respectively, in these three groups of patients. Based on these results, the authors offer guidelines for the management of patients with prolactin-secreting pituitary adenomas associated with exceptionally high serum prolactin levels. The surgical control rate of 68% in Group A seems to justify surgery for these patients, while primary medical care with bromocriptine is recommended for most patients with serum prolactin levels over 500 ng/ml.
Bilateral trigeminal neuralgia: a 14-year experience with microvascular decompression
Authors: Pollack Ian F. , Jannetta Peter J. , Bissonette David J.
Published: May 2009

✓ Thirty-five patients with trigeminal neuralgia (TN) bilaterally underwent posterior fossa microvascular decompression (MVD) between 1971 and 1984. They comprised 5.0% of a larger series of 699 patients with TN who underwent MVD during that interval. Compared to the subgroup of 664 patients with only unilateral symptoms, the population with bilateral TN included a greater percentage of females (74% vs. 58%, p < 0.1), a higher rate of “familial” TN (17% vs. 4.1%, p < 0.001), and an increased incidence of additional cranial nerve dysfunction (17% vs. 6.6%, p < 0.05) and hypertension (34% vs. 19%, p < 0.05).

Of the 35 patients with bilateral TN, 10 underwent bilateral MVD (22 procedures) and 25 underwent unilateral MVD (30 procedures). In the latter patients, pain on the nonoperative side was well controlled with medication alone or had previously been treated by ablative procedures. Good or excellent pain control was achieved after one MVD was performed in 40 of the 45 sides treated (89%), and was maintained 1, 5, and 10 years after surgery in 82%, 66%, and 60%, respectively, based on life-table analysis. Six of 10 patients with recurrent symptoms underwent repeat unilateral MVD. Good or excellent long-term pain control was maintained in all six. With these repeat procedures included, symptom control at 1, 5, and 10 years after initial surgery was maintained in 87%, 78%, and 78% of the treated sides, respectively. Overall, 26 of 35 patients (74%) maintained good or excellent pain relief throughout the duration of the study (mean follow-up period 75 months) without resumption of regular medication usage. Although preoperative neurological deficits resulting from previous ablative procedures were seen in the majority of patients before MVD, no patient developed new major trigeminal sensory loss or masseter weakness after MVD. Operative mortality was zero. The results indicate that posterior fossa MVD is an effective and relatively safe treatment for the majority of patients with bilateral “idiopathic” TN, avoiding the risks of bilateral trigeminal nerve injury seen with other approaches.
Serial changes in acute extradural hematoma size and associated changes in level of consciousness and intracranial pressure
Authors: Sakai Hidemitsu , Takagi Hiroshi , Ohtaka Hirotoshi , Tanabe Takamaru , Ohwada Takashi , Yada Kenzoh
Published: May 2009

✓ The authors report the cases of 37 patients encountered during the past 4 years who exhibited acute extradural hematoma but were initially treated conservatively because no or only small hematomas were observed on admission. The frequency of hematoma enlargement, hematoma size, and changes in the level of consciousness and intracranial pressure (ICP) were examined in these patients. The hematomas enlarged in 24 (64.9%) of the 37 patients, and attained a maximum thickness of 25 mm or greater in 19 patients (51.3%). The level of consciousness could be closely observed during enlargement of the hematomas in 13 patients: the level remained unchanged in eight, deteriorated in two, and improved in three, indicating relative stability in the state of consciousness despite the marked changes in hematoma size. The patients whose hematoma enlarged after the initial examination included three who underwent initial CT examination 5 hours after the injury. In five patients enlargement of extradural hematomas was observed unexpectedly during conservative treatment under ICP monitoring.

The ICP also remained stable in three patients until the follow-up examination, but showed a rapid increase in two after a period of stability. However, there was no difference in the final size of the hematomas between the patients showing an increase in ICP and those who did not. These findings suggest that extradural hematomas enlarge progressively at rates varying with the condition of the source of hemorrhage. Moreover, a period of stability in the level of consciousness, such as the lucid interval seen in patients with extradural hematoma, is considered to be a period during which compensatory mechanisms can maintain the stability of the intracranial condition during progressive enlargement of the hematoma.
Intracranial pressure and outcome in adult encephalitis
Authors: Barnett Gene H. , Ropper Allan H. , Romeo June
Published: May 2009

✓ The relationship between intracranial pressure (ICP) and outcome was studied in 10 adults with encephalitis. Eight had biopsy-proven herpes simplex encephalitis, one had acute hemorrhagic leukoencephalitis, and in one case the cause of encephalitis was unknown. Monitoring of ICP was instituted because of clinical deterioration or computerized tomography evidence of brain swelling, and was begun a mean of 7 days after the orlset of symptoms and continued for a mean of 9 days.

All five survivors, but only one of the five fatalities, had an initial ICP of less than 12 mm Hg (p < 0.05). Four patients with a mean daily ICP of less than 20 mm Hg survived, whereas five of six patients with higher ICP's died (p < 0.05). Peak ICP did not occur until the 12th day of illness on average. The Glasgow Coma Scale score at the time the ICP monitor was inserted did not correlate with outcome. Intracranial pressure monitoring in severe encephalitis may be a useful adjunct for therapy and an indicator of prognosis.