bluuebunny/crossref_metadata_2025 huggingface dataset:
Arachnoid cysts of the Sylvian fissure
Authors: Go K. Gwan , Houthoff Hendrik-Jan , Blaauw Engbert H. , Havinga Piet , Hartsuiker Johannes
Published: May 2009

✓ Morphological and enzyme ultracytochemical evidence is presented to support the contention that the walls of arachnoid cysts secrete fluid. Clinical evidence has already suggested this phenomenon, including intracranial pressure elevation and expansion in some cases, and the observation that arachnoid cysts constitute closed compartments with a fluid content that cannot be derived from other cerebrospinal fluid-containing spaces. Ultrastructurally, the cyst lining showed a similarity to subdural neurothelium and the neurothelial lining of arachnoid granulations in such morphological features as intercellular clefts with sinusoid dilatations, desmosomal intercellular junctions (upon which tonofilaments may be abutting), pinocytotic vesicles, multi-vesicular bodies, lysosomal structures, and the presence of a basal lamina. Some of these features, together with the presence of microvilli on the luminal surface, are consistent with fluid secretion. Moreover, enzyme cytochemistry demonstrated (Na+ + K+)-ATPase in the plasma membranes lining the cavity, either directly (the apical membranes), or via the intercellular clefts (the basolateral membranes), and, with alkaline phosphatase occupying the opposite plasma membranes, this structural organization indicates fluid transport toward the lumen. It may be surmised that arachnoid cysts derive from subdural neurothelium differentiating towards arachnoid villus mesothelium.
Single-beam radiotherapy knife
Authors: Heifetz Milton D. , Wexler Marilyn , Thompson Ronald
Published: May 2009

✓ A feasibility study reveals that a standard linear accelerator, with only slight modification, can function in a manner similar to Leksell's multiple cobalt radiation device. A high radiation dose can be delivered to a 1-cm or 0.5-cm volume target with insignificant radiation effect on the surrounding tissue.
Survival of nerve allografts in sensitized rats treated with cyclosporin A
Authors: Zalewski Andrew A. , Gulati Adarsh K.
Published: May 2009

✓ This study examined the effect of immunosuppressive treatment with cyclosporin A (Cy-A) on the survival of nerve allografts in sensitized rats. Nerve- or skin-sensitized untreated rats rejected a second nerve allograft of the same genotype as the first in an accelerated manner. In this situation, only a few host axons grew into the proximal 1 cm of a 4 cm-long nerve allograft. However, if sensitized rats were given Cy-A (10 mg/kg daily), the second nerve allograft survived, and numerous host axons regenerated through the 4-cm length of the allograft. These results indicated that Cy-A was an effective immunosuppressive agent in sensitized rats. We conclude that, in rats, donor-specific sensitization is not a contraindication to the use of nerve allografts to aid in the repair of injured nerve when Cy-A is used for immunosuppression.
Craniopharyngioma of the cerebellopontine angle
Authors: Altinörs Nur , Şenveli Engin , Erdoğan Ahmet , Arda Nuri , Pak Işin
Published: May 2009

✓ The authors report a case of craniopharyngioma presenting in the right cerebellopontine angle. The tumor was removed totally. The purpose of this report is to record this very unusual localization of a craniopharyngioma.
Chorea as a manifestation of epidural hematoma
Authors: Adler John R. , Winston Ken R.
Published: May 2009

✓ A child with epidural hematoma presented with choreiform movements which promptly resolved following the evacuation of the hematoma.
Cerebral circulation and metabolism
Authors: Siesjö Bo K.
Published: May 2009

✓ Recent developments in the field of cerebral circulation and metabolism are reviewed, with emphasis on circulatory and metabolic events that have a bearing on brain damage incurred in ischemia. The first part of the treatise reviews aspects of cerebral metabolism that provide a link to the coupling of metabolism and blood flow, notably those that lead to a perturbation of cellular energy state, ionic homeostasis, and phospholipid metabolism. In the second part, attention is focused on the derangement of energy metabolism and its effects on ion fluxes, acid-base homeostasis, and lipid metabolism. It is emphasized that gross brain damage, involving edema formation and infarction, is enhanced by tissue acidosis, and that neuronal damage, often showing a pronounced selectivity in localization, appears related to a disturbed Ca2+ homeostasis, and to Ca2+-triggered events such as lipolysis and proteolysis.
Serial measurement of regional cerebral blood flow in patients with SAH using 133Xe inhalation and emission computerized tomography
Authors: Mickey Bruce , Vorstrup Sissel , Voldby Bo , Lindewald Helle , Harmsen Aage , Lassen Niels Alexander
Published: May 2009

✓ A noninvasive three-dimensional method for measuring cerebral blood flow (CBF), xenon-133 inhalation and emission computerized tomography, was used to investigate the CBF changes accompanying delayed neurological deterioration following subarachnoid hemorrhage (SAH). A total of 67 measurements were performed on 20 patients in Hunt and Hess' clinical Grades I to III in the first 21 days post SAH. Five patients with normal CBF tomograms on admission developed delayed neurological deficits in the 2nd week after hemorrhage, at which time repeat CBF tomograms in four patients revealed large areas of well defined regional flow decrease in the vascular territories of the anterior or middle cerebral arteries. Severe vasospasm was noted in three of these patients in whom arteriography was performed in the 2nd week post SAH. Diffuse bihemispheric CBF decreases were noted later in the course of delayed neurological deficits; however, measurements obtained soon after the onset of focal symptoms suggest that the only CBF decreases directly produced by vasospasm in Grade III patients are regional changes.
Assessment of level of consciousness following severe neurological insult
Authors: Stanczak Daniel E. , White James G. , Gouview William D. , Moehle Kurt A. , Daniel Michael , Novack Thomas , Long Charles J.
Published: May 2009

✓ An alternative method of coma assessment is presented and compared with the Glasgow Coma Scale. The merits of the Comprehensive Level of Consciousness Scale as a research tool are presented. An analysis of 101 consecutive consciousness-impaired patients with their short-term outcome is presented.
Spontaneous carotid-cavernous fistulas: clinical, radiological, and therapeutic considerations
Authors: Viñuela Fernando , Fox Allan J. , Debrun Gerard M. , Peerless Sydney J. , Drake Charles G.
Published: May 2009

✓ Sixty-five carotid-cavernous fistulas were studied at University Hospital, London, Canada, from 1978 to 1982, 20 of which fulfilled the clinical and angiographic criteria of a spontaneous carotid-cavernous fistula. Of these 20 fistulas, 17 were unilateral, and three were bilateral. In 18 cases the angiographic findings were typical of an arteriovenous malformation (AVM), and in two a ruptured giant intracavernous aneurysm was found. These patients were treated according to whether they had a nonresolving or progressive cavernous sinus syndrome or deterioration of vision. The cavernous dural AVM's were treated with polyvinyl-alcohol and/or isobutyl-2-cyanoacrylate (IBCA) embolization of the external carotid artery blood supply. Two patients underwent postembolization surgical procedures. The detachable balloon technique was used to occlude the fistulas associated with the two giant ruptured intracavernous aneurysms and a small dural intracavernous AVM. Eight patients received no therapy; in two, spontaneous obliteration of the fistula occurred. Of the nine cavernous AVM's embolized with particles and/or IBCA, successful transvascular embolization was achieved in seven cases, and partial embolization followed by surgery in two cases. Successful balloon obliteration of the giant intracavernous ruptured aneurysm was obtained in two cases. In one patient, right hemiplegia with aphasia resulted from reflux of IBCA emboli through the artery of the foramen rotundum into the left middle cerebral artery.
Estrogen and progesterone receptors in meningiomas
Authors: Cahill David W. , Bashirelahi Nasir , Solomon Louis W. , Dalton Thomas , Salcman Michael , Ducker Thomas B.
Published: May 2009

✓ Two-thirds of all meningiomas and four-fifths of intraspinal and sphenoidal meningiomas occur in women. Meningiomas frequently enlarge or become symptomatic during pregnancy or during the luteal phase of the menstrual cycle. There is an increased incidence of meningiomas in women with breast carcinoma.

In a series of 23 patients with meningiomas, the authors assayed biopsy specimens of the tumor for the presence of estrogen (ER) and progesterone (PR) receptors, using glycerol density gradient centrifugation and dextran-coated charcoal techniques. Significant levels of ER were found in only 17% of the patients, while significant PR levels were detected in 39%. Only one of the 16 tumors from female patients had significant ER levels, whereas three of the seven tumors from men had significant ER levels. Eight of the 16 tumors in women had significant PR levels, whereas only one of the seven tumors in men had a significant PR level. Thus, three out of four tumors with definite ER were from men, whereas eight of nine tumors with definite PR were from women. Of the eight women whose tumors contained PR, three were premenopausal and five postmenopausal. The single tumor with high levels of PR in the male patient was histologically atypical.

The results of this series were compared with six published series of sex steroid assays in meningiomas. These seven series were divided into two groups: one group included two reports from the same laboratories in France, and the other the remaining five reports. Much higher percentages of both ER- and PR-positive tumors were reported from the French group. The authors suggest that this discrepancy may be due to the use of preoperative glucocorticoid therapy in the series from the United States.

Since meningiomas are known to enlarge during periods when levels of circulating progestins are high, the presence of significant quantities of PR in a high percentage of tumors may have therapeutic implications for recurrent, malignant, or incompletely excised tumors, or for medically fragile patients. Conversely, since meningiomas are not known to enlarge during the proliferative phase of the menstrual cycle or with exogenous estrogen therapy, the small number of tumors positive for ER may indicate that ER lacks clinical significance. High levels of PR found in a small group of histologically aggressive tumors in several series may indicate that hormonal therapy may be especially useful in this difficult subset of patients.
The pharmacology of diaziquone given in intravenous or intracarotid infusion to normal and intracranial tumor-bearing puppies
Authors: Egorin Merrill J. , Bellis Edwin H. , Salcman Michael , Collins Jerry M. , Spiegel James F. , Bachur Nicholas R.
Published: May 2009

✓ Diaziquone (also called “aziridinyl benzoquinone,” or AZQ), an antitumor drug designed to penetrate the blood-brain barrier, has demonstrated activity against central nervous system (CNS) neoplasms. Four-hour infusions of carbon-14 (14C)-labeled AZQ (0.8 mg/kg) were given via the left common carotid artery or left brachial vein to two groups of puppies. A third group, harboring a transplantable canine glioma, received 14C-AZQ by intravenous infusion. Levels of chloroform (CHCl3)-extractable 14C (AZQ only) and total 14C (AZQ and metabolites) were determined in serial samples of plasma and cerebrospinal fluid (CSF). At the end of the infusion time, total and CHCl3-extractable 14C levels were determined in brain and tumor. Intra-arterial infusion of AZQ caused no histological abnormalities in the retina or brain. For the intravenous infusion group, the concentrations of CHCl3-extractable 14C (in nmol/ml or nmol/gm) were 0.68, 0.35, and 0.84 for plasma, brain, and CSF, respectively. For the intra-arterial infusion group, the concentrations were 0.25, 0.13, and 0.32 for plasma, brain, and CSF, respectively.

Comparison of right and left hemispheres following intra-arterial infusion showed a slightly higher concentration of 14C in the ipsilateral (left) hemisphere, with concentrations (nmol/gm) of CHCl3-extractable 14C/total 14C of 0.15/0.87 on the left and 0.12/0.65 on the right. Concentrations (nmol/gm) of CHCl3-extractable 14C/total 14C in brain and tumor were 0.60/1.24 and 0.58/1.65, respectively. In tumor-bearing animals, tumor and surrounding brain contained similar concentrations of AZQ, but there were higher concentrations of metabolites in tumor. This may reflect different metabolism of AZQ within brain and tumor or different permeability to metabolites. This study revealed that AZQ enters the CNS and brain-tumor tissue in substantial concentrations and that there is no significant advantage to intracarotid infusion of AZQ.
Repair of spinal dural defects
Authors: Keller Jeffrey T. , Ongkiko Carlos M. , Saunders Mary C. , Mayfield Frank H. , Dunsker Stewart B.
Published: May 2009

✓ The search for an ideal substance for duraplasty has stimulated clinical and experimental investigations. To date a large number of materials have been employed for dural repair, although there is as yet no unanimity regarding the ideal material. Most of these studies have been concerned with cranial dura, and spinal duraplasty has received less attention. This study was designed to examine the repair of spinal dural defects in the dog. The materials chosen for this experiment were autologous fat, a polyester fiber mesh (Mersilene) and siliconecoated Dacron (Dura Film). Nineteen dogs were used in this study. Following lumbar laminectomy and the excision of elliptical pieces of dura (1.0 × 0.5 cm) at three noncontiguous levels, each of the defects was repaired using one of the three materials. Groups of animals were sacrificed at each of 3, 6, 12, and 24 weeks after dural repair. The lumbar region was removed en bloc and prepared for histological examination. Repair of the dural opening was achieved in all cases. The polyester fiber mesh was quite effective for dural repair, serving as a scaffold through which a neomembrane grew and united the dural edges. The results with autologous fat were similarly favorable. On the other hand, results with silicone-coated Dacron showed encapsulation by connective tissue, with the ventral aspect of the graft frequently compressing the underlying cord.
Intradiscal pressure-volume response: a methodological contribution to chemonucleolysis
Authors: Brock Mario , Görge Hans-Hermann , Curio Gabriel
Published: May 2009

✓ A new method is presented to verify whether a lumbar disc is degenerated prior to chemonucleolysis. This consists in rapid injection of a 0.3-ml bolus of saline into the center of the disc (through the needle employed for chemonucleolysis), under continuous recording of the intradiscal pressure changes caused by this volume load. If the intradiscal pressure falls below 600 mm Hg within 2 minutes after the injection, there is a high probability (p < 0.001) that the disc is degenerated. This method has many advantages: it obviates additional injection of contrast medium prior to chemonucleolysis, it prevents inhibition of chymopapain by the contrast medium, it saves time, and it reduces the total amount of fluid injected during chemonucleolysis.
Long-term follow-up review of cases of Parkinson's disease after unilateral or bilateral thalamotomy
Authors: Matsumoto Keizo , Shichijo Fumio , Fukami Tsuneharu
Published: May 2009

✓ Follow-up reviews were carried out on 86 of 103 patients with Parkinson's disease who underwent unilateral or bilateral ventrolateral (VL) thalamotomy in the period from 1964 to 1969. Of these 86 patients, 64 received unilateral surgery, and 22 bilateral surgery. The follow-up periods were at least 10 years from the operation (from the second intervention in cases with bilateral procedures). In the group that received unilateral surgery, no progression after surgery was seen in three of six patients classified preoperatively in Grade I (Hoehn and Yahr's Grade 1), nine of 20 patients in Grade IIa (Hoehn and Yahr's Grade 2), 13 of 23 patients in Grade IIb (Hoehn and Yahr's Grade 3), and six of 15 patients in Grade III (Hoehn and Yahr's Grade 4). In the group that received bilateral surgery, one of three patients in Grade I and one of 11 patients in Grade IIa before the second intervention maintained continuous full social activities for over 10 years after the second surgery without any medication. In addition, eight of 11 patients classified preoperatively in Grade IIa and five of eight patients in Grade IIb seemed to show no progression after the second operation; four of 22 patients stopped taking their medication because of improvement in their symptoms. No patient who received bilateral surgery had progression of the disease to death. Observations suggested the efficacy of thalamic surgery, not only for improvement of motor symptoms but also for reducing progression of the disease, although no control study was made. Thalamotomy is still used to treat Parkinson's disease as an alternative to current medical treatments, such as L-dopa therapy.
Surgical treatment of tentorial arteriovenous malformations draining into the subarachnoid space
Authors: Grisoli François , Vincentelli François , Fuchs Sylvaine , Baldini Mario , Raybaud Charles , Leclercq Toussaint A. , Vigouroux Robert Pierre
Published: May 2009

✓ Four patients with tentorial arteriovenous malformations (AVM's) were treated surgically. The operative findings in the first case suggested that clipping of the draining vein close to the AVM may result in complete cure. The three subsequent cases were treated with this technique. The clinical and radiological implications are discussed.
Dural arteriovenous malformation in the posterior fossa associated with intracerebellar hematoma
Authors: Sakaki Saburo , Fujita Hitoshi , Kohno Kanehisa , Matsuoka Kenzo
Published: May 2009

✓ A case of an infratentorial dural arteriovenous malformation associated with an intracerebellar hematoma is reported. This malformation was fed by meningeal branches of the right vertebral artery and was drained exclusively by pial veins in the posterior fossa.
Catecholamine-secreting malignant schwannoma in a patient with multiple intracranial aneurysms
Authors: Hasegawa Hiroshi , Bitoh Shoji , Otsuki Hideo , Fujiwara Masaaki , Yamamoto Tomio , Kobayashi Yasushi
Published: May 2009

✓ A case is reported of malignant schwannomatosis (malignant transformation of von Recklinghausen's disease) with catecholamine production in a patient with multiple intracranial aneurysms. The patient had a history of episodic hypertension and elevated levels of catecholamines in the serum and 24-hour urinary excretion. Postmortem examination revealed diffuse central nervous sytem (CNS) dissemination of the tumor from the thoracolumbar spinal malignant schwannoma. A high concentration of catecholamines was demonstrated in the tumor tissue, and histochemical and electron microscopy studies suggested the presence of catecholamines in the cytoplasm of some of the tumor cells. This patient's clinical and radiological features, including severe headache, vomiting, stiff neck, ptosis of the eye ipsilateral to the internal carotid-posterior communicating artery aneurysms, and local arterial narrowing, mimicked those of subarachnoid hemorrhage from a ruptured aneurysm. However, the clinical picture was caused by diffuse CNS dissemination of the tumor, another primary malignant schwannoma of the oculomotor nerve, and intimal fibrous thickening of the arterial wall.
Modification of the Richmond subarachnoid screw for monitoring intracranial pressure
Authors: Swann Karl W. , Cosman Eric R.
Published: May 2009

✓ The authors describe a modification of a subarachnoid screw for monitoring intracranial pressure by hydrostatic coupling of the subarachnoid space to an external transducer. The device can be used in both children and adults, and features more assured placement of the distal tip, increased stability, and enhanced safety on insertion.
Experimental anaerobic brain abscess
Authors: Britt Richard H. , Enzmann Dieter R. , Placone Richard C. , Obana William G. , Yeager Anne S.
Published: May 2009

✓ The neuropathological progression of brain abscess formation induced by a mixed anaerobic culture of Bacteroides fragilis and Staphylococcus epidermidis was studied experimentally in dogs. Histological findings were correlated with computerized tomographic (CT) brain scans. The evolution of brain abscess formation could be divided into three stages based on histological criteria: early cerebritis (Days 1 to 3); late cerebritis (Days 4 to 9); and capsule formation (Day 10 and later). Capsule formation could not be divided into early and late stages because encapsulation was delayed compared with a previously reported model of alpha-Streptococcus brain abscess. Histologically, there was evidence for a very virulent infection. Leptomeningitis was significant even in the late stages. Early ventricular rupture occurred in 25% of the animals. A pattern of extensive purulent encephalitis was seen in 25% of the animals. In the early cerebritis stage, blood vessels near the necrotic center were engorged and were surrounded by hemorrhage and/or protein-rich fluid. Cerebral edema was extensive. Although fibroblasts appeared in late cerebritis, there was marked delay of capsule formation. Three-week-old lesions still had areas of incomplete capsule formation and foci of uncontrolled infection. In the cerebritis stages, CT scans showed an area of ring enhancement which was incomplete on early scans (at 5 minutes after injection of contrast material) but partially filled in and thickened on delayed scans (at 20 to 45 minutes). On even later delayed scans there was no decrease in intensity of ring enhancement. Lesions in which capsule formation occurred also showed ring enhancement, but delayed scans showed a decrease in the intensity of enhancement. The lesions that ruptured into the ventricular system showed atypical CT findings, with either lack of contrast enhancement (histologically there was minimal cerebritis adjacent to the abscess cavity) or a marked delay in contrast enhancement (cerebritis was more extensive and corresponded to the width of ring of enhancement). This study suggests that Bacteroides fragilis is a virulent organism in the brain. The developing abscesses enlarged quickly, were prone to early ventricular rupture, and showed incomplete and delayed encapsulation.
A randomized placebo-controlled double-blind trial of nimodipine after SAH in monkeys
Authors: Espinosa Francisco , Weir Bryce , Overton Thomas , Castor William , Grace Michael , Boisvert Donald
Published: May 2009

✓ The authors have developed a method to induce chronic cerebral vasospasm after subarachnoid hemorrhage (SAH) in monkeys. With microsurgical techniques, 33 monkeys had a frontotemporal craniectomy and unilateral opening of the subarachnoid cisterns. Cerebrospinal fluid was drained and a fresh hematoma, obtained from an average of 7 ml of autologous blood, was carefully placed against the major arteries of the anterior circulation on one side. The 30 monkeys studied for 7 to 14 days after the SAH were allocated randomly to two treatment groups of 15: one group received placebo and the other nimodipine, 1 mg/kg every 8 hours. Indices monitored before and after SAH included neurological status, cerebral blood flow, computerized tomography, and angiographic vessel caliber.

In the placebo group, delayed ischemic neurological deficit developed in one monkey 4 days after clot placement and was present at sacrifice on Day 14. No such deficit occurred in the nimodipine group. The effect of nimodipine on vessel caliber at this dosage was equivocal. Significant vasospasm (31% to 100% reduction in vessel caliber) developed in 87% (26 of 30) of the animals. Overall, vasospasm was slightly more common in the placebo group: in this group, on Days 7 and 14, the incidence of vasospasm was significantly higher (p < 0.05) than in the nimodipine group. However, the average percentage reduction in vessel caliber of the maximally constricted vessel in each monkey was not significantly different between the two groups.
A randomized placebo-controlled double-blind trial of nimodipine after SAH in monkeys
Authors: Espinosa Francisco , Weir Bryce , Shnitka Theodor , Overton Thomas , Boisvert Donald
Published: May 2009

✓ Chronic cerebral vasospasm was induced in monkeys by placement of an autologous blood clot after the basal cisterns had been opened over the arteries of the circle of Willis on one side. The experimental protocol was detailed in Part 1 of this paper. Twenty of the 30 monkeys studied from both groups (one receiving placebo and the other nimodipine) underwent cerebral fixation (Day 14) at controlled pressure by intra-arterial perfusion. The arteries at the base of the brain were studied by light microscopy and scanning (SEM) and transmission electron microscopy (TEM). Cerebral angiography on Day 7 showed that vasospasm was significantly more common (p < 0.0001) and more severe (p < 0.01) on the clot side compared to the control or non-clot side. Vasospasm was less severe on Day 14, just before sacrifice. On SEM, 80% of the 20 middle cerebral artery (MCA) specimens that had been in spasm (Day 7) showed marked corrugation, and in some the endothelium had a fish-scale appearance. All of the 10 MCA's on the clot side examined by TEM that had been in spasm (Day 7) showed marked changes such as endothelial swelling, subendothelial proliferation, corrugation of the elastic lamina, and myonecrosis. With few exceptions, none of the basilar arteries or MCA's on the non-clot (control) side showed any abnormalities. The pathological findings of vessels in spasm were considered to be slightly less severe in the nimodipine group; however, the trial drug (1 mg/kg/8 hrs) did not prevent such abnormalities from occurring. The ultrastructural changes in the arterial walls of specimens from both placebo and nimodipine groups in vasospasm are described. Since dramatic changes are present in the vessel walls even after radiologically visible vasospasm has almost completely abated, we believe that vasospasm is due to long-lasting smooth-muscle constriction and not to vessel wall thickening caused by a cellular or subcellular infiltrate.
Nature of the vasoactive substance in CSF from patients with subarachnoid hemorrhage
Authors: Sasaki Tomio , Asano Takao , Takakura Kintomo , Sano Keiji , Kassell Neal F.
Published: May 2009

✓ The purpose of this experiment was to study the nature of vasoactive substance in cerebrospinal fluid (CSF) from patients with aneurysmal subarachnoid hemorrhage. The authors have examined the effects of disulfide bond-reducing agents, a sulfhydryl group oxidizing agent, and specific antagonists of so-called “classical” neurotransmitters on the in vitro isometric contraction of canine basilar arterial strips induced by bloody human CSF. The disulfide bond-reducing agents dithiothreitol (10−4 M) and dithioerythritol (10−4 M) suppressed the contraction induced by bloody CSF by an average of 40.3% and 61.2%, respectively. This suppression was achieved under conditions that did not alter KCl-induced contraction. The sulfhydryl group oxidizing agent, 5,5′-dithiobis-(2-nitrobenzoic acid), 10−4 M, reversed the inhibitory effect of dithioerythritol on the contractile response to bloody CSF. No significant suppression of any response in any preparation was observed with methysergide (10−7 M), mepyramine (10−7 M), phenoxybenzamine (10−5 M), propranolol (10−6 M), or atropine (10−6 M).

These results indicate that disulfide bonds in the arterial smooth-muscle cells are involved in the contractile responses of canine basilar artery to bloody CSF. Prostaglandins, hemoglobin, and lipid hydroperoxides may all be spasmogens in bloody CSF, while serotonin, histamine, norepinephrine, and acetylcholine are probably not involved.
Subdural strip electrodes for localizing epileptogenic foci
Authors: Wyler Allen R. , Ojemann George A. , Lettich Ettore , Ward Arthur A.
Published: May 2009

✓ Surgical removal of epileptogenic brain is indicated for treatment of many medically refractory focal seizure disorders. One of the important factors in providing good results from surgery is the accuracy of identifying the epileptogenic focus. However, accurate localization may be difficult when only standard scalp recordings are used. Many epilepsy centers have used intracranial recording techniques to better define regions of cortical epileptogenicity. Although subdural strip electrodes were first utilized many years ago, the more popular method of intracranial recording has been by intracortical depth electrodes. The authors present their method of placing subdural strip electrodes for extensive recordings from the cortex. To date, this method has been used to provide continuous monitoring of the electrocorticogram in 28 patients for periods up to 3 weeks, with only two minor complications. This procedure is relatively safe and a valuable alternative to placing intracortical depth electrodes.
Brain tissue pressure: physiological observations in anesthetized cats
Authors: Iannotti Fausto , Hoff Julian T. , Schielke Gerald P.
Published: May 2009

✓ This study of direct tissue pressure measurement from brain parenchyma in 25 anesthetized cats focuses on steady-state observations and responses to some common physiological manipulations. Tissue pressure recording by a needle system can be done accurately without significant alterations of the blood-brain barrrier, brain water content, regional cerebral blood flow, and cerebrovascular reactivity to changes in PaCO2 and cerebral perfusion pressure. Methodological details, including in vitro and in vivo validation, are described.
Surgical approaches to the orbit
Authors: Maroon Joseph C. , Kennerdell John S.
Published: May 2009

✓ The authors review their experience with over 300 patients with orbital tumors, and summarize their surgical techniques and indications for each surgical approach. A fronto-orbital approach is described which is used for tumors with intracranial extension and for those located in the orbital apex and deep medial orbital compartment. Lateral micro-orbitotomy is used for tumors located in the superior, temporal, or inferior compartment of the orbit and those in the lateral apex. A medial microsurgical approach is used for tumors located medial to the optic nerve but not deep in the apex. By thus approaching tumors directly, optimal exposure is obtained and functional deficits are minimized. The pertinent surgical anatomy is illustrated and the technique of fine-needle aspiration biopsy is discussed.
Experimental study on the pathogenesis of heat stroke
Authors: Shih Chun-Jen , Lin Mao-Tsun , Tsai Shin-Han
Published: May 2009

✓ A heat-balance study was carried out on conscious rabbits exposed to ambient temperatures (Ta) from 8° to 40°C. At Ta = 40°C, heat gain exceeded heat loss and led to hyperthermia and heat stroke, and the latency for the onset of heat stroke was found to be around 87 minutes. At the onset of heat stroke, the comatose animals showed higher levels of rectal temperature, ear skin blood flow, respiratory evaporative heat loss, metabolic rate, intracranial pressure (ICP), and cerebral water content as compared to those of control animals (kept at an ambient temperature of 24°C). Before the start of heat stress, the animals had an average mean arterial blood pressure (MABP) of 94 mm Hg and cerebral perfusion pressure (CPP) of 80 mm Hg. However, at the onset of heat stroke, the average MABP and CPP decreased to 67 and 19 mm Hg, respectively. The reduction in CPP at the onset of heat stroke was due to both a decrease in MABP and an increase in ICP. In addition, the comatose animals which received an intravenous infusion of 10% glycerol (3 ml/min) had a survival time (interval between onset of heat stroke and death) longer than that of the comatose animals which received the control-vehicle solution. The prolongation of survival time in the glycerol-treated animals may be due to lower rectal temperature, lower cerebral water content, or lower ICP during the development of heat stroke. The present data indicate that not only hyperthermia but also cerebral edema, intracranial hypertension, decreased MABP, and decreased CPP are the main causes of heat stroke. The therapeutic values of glycerol on heat stroke may be related to the depressant action on cerebral edema, intracranial hypertension, and body temperature.
Phenoxybenzamine in the treatment of causalgia
Authors: Ghostine Salim Y. , Comair Youssef G. , Turner Donn M. , Kassell Neal F. , Azar Camille G.
Published: May 2009

✓ Forty consecutive cases of causalgia treated during a 7-year period are presented. The patients ranged in age between 17 and 55 years, and all patients were males who received their nerve injuries from missile or shrapnel wounds. The greater occipital nerve was involved in two cases, median nerve in 10, sciatic nerve in 12, brachial plexus in seven, cauda equina in five, and multiple nerves in four cases. Each patient was treated with phenoxybenzamine, a postsynaptic α1-blocker and presynaptic α2-blocking agent. The drug was given orally in gradually increasing increments until a maximum daily dose of 40 to 120 mg was reached. Duration of treatment was usually 6 to 8 weeks. Total resolution of pain was achieved in all cases. The follow-up period ranged between 6 months and 6 years. Side effects of phenoxybenzamine were minimal and transient, consisting primarily of mild orthostatic hypotension and ejaculatory problems. We conclude that oral phenoxybenzamine is a simple, safe, and effective treatment of causalgia.
Failure of tetracaine to reverse spinal cord injury in the cat
Authors: Ford Ronald W. J. , Malm David N.
Published: May 2009

✓ Beginning 30 minutes after acute spinal cord injury, cats were treated by the administration of continuous spinal anesthesia for 8 hours. This was achieved by the intermittent injection of hyperbaric tetracaine into the subarachnoid space at the site of injury via an indwelling catheter. There were no significant differences in functional recovery or histologically assessed tissue preservation between treated cats and concurrently managed control animals. The indwelling subarachnoid catheter used for drug administration was found to have no significant effect on the spinal cord injury.
Angiographic disappearance of multiple dural arteriovenous malformations
Authors: Kataoka Kazuo , Taneda Mamoru
Published: May 2009

✓ Angiographic disappearance of two dural arteriovenous malformations (AVM's) in different locations in one case is reported. One of the AVM's involved the right transverse sinus, and the other involved the superior sagittal sinus. The patient's presenting symptoms were due to obstructive hydrocephalus resulting from a small intraventricular hemorrhage that was diagnosed by computerized tomography on admission. The symptoms cleared 25 hours after the ictus in conjunction with improvement of hydrocephalus. The AVM involving the right transverse sinus was supplied by the occipital artery, but ligation of that artery was not successful in eliminating the anomaly. One year later, follow-up angiography revealed disappearance of both dural AVM's.
Plasma-cell granuloma of the fourth ventricle
Authors: Maeda Yukio , Tani Eiichi , Nakano Masaru , Matsumoto Tsuyoshi
Published: May 2009

✓ The case is presented of a 36-year-old woman with a plasma-cell granuloma arising in the fourth ventricle. The mass appeared on computerized tomography as a well circumscribed area of slightly high density that was markedly enhanced with contrast medium. Microscopic examination showed a mixed-cell population with a predominance of plasma cells, and the tumor was characterized immunohistochemically by polyclonal plasma-cell proliferation.
Interhemispheric subdural hematoma
Authors: Fruin Alan H. , Juhl Gregory L. , Taylon Charles
Published: May 2009

✓ A case of interhemispheric subdural hematoma (ISH) is presented and discussed. This disorder is a rare form of intracranial hemorrhage, which classically presents as an isolated paresis of one leg or a hemiparesis worse in the leg than the arm. The majority of cases are due to occipital trauma because of the anatomy of the bridging veins. Chronic interhemispheric hematomas are rare since the natural history of these lesions is to spread out over the cerebral convexity. Conservative treatment for ISH may be beneficial unless neurological deterioration necessitates early operative intervention.
Epidermoid tumor presenting as tension pneumocephalus
Authors: Clark Jonathan B. , Six Eric G.
Published: May 2009

✓ The authors report a patient with an epidermoid tumor that eroded through the frontal sinus, causing an acute neurological deficit secondary to tension pneumocephalus. The historical perspective, radiographic features, and pathophysiological mechanisms are discussed.
Peripheral nerve injury by chymopapain injection
Authors: Mackinnon Susan E. , Hudson Alan R. , Llamas Faustino , Dellon A. Lee , Kline David G. , Hunter Dan A.
Published: May 2009

✓ Chymopapain injected into the intervertebral disc space (chemonucleolysis) has been used clinically in patients with disc disease with success. Neurosurgical complications secondary to the procedure have, however, been reported. In this study, the authors have investigated the possible neurotoxic effect of chymopapain on the peripheral nerve in rat and primate models. While the extrafascicular injection caused no nerve fiber damage, the intrafascicular injection caused dose-related nerve fiber damage in both species.
Central nervous system mass lesions in the acquired immunodeficiency syndrome (AIDS)
Authors: Levy Robert M. , Pons Vincent G. , Rosenblum Mark L.
Published: May 2009

✓ The authors present the cases of nine patients with acquired immunodeficiency syndrome (AIDS) and intracerebral mass lesions, who were evaluated at the University of California, San Francisco, between April, 1979, and July, 1983. Eight patients were confirmed homosexual males, and none was Haitian. Their average age was 38.8 years. Tissue diagnosis was made in all patients from brain biopsy or autopsy material. Three patients initially presented for evaluation of their neurological deficits, while the other six already carried the diagnosis of AIDS at admission. Seven patients presented with multiple intracranial lesions and two had polymicrobial infection. In this series, three patients had Toxoplasma gondii brain abscesses, two had primary lymphoma, two had metastatic Kaposi's sarcoma of the central nervous system (CNS), two had focal cytomegalovirus encephalitis and one each had cryptococcal and Candida albicans brain abscesses. The clinical presentation, radiological evaluation, and serodiagnostic study of these patients were not helpful in establishing the nature of the CNS lesions. Brain biopsy is considered by the authors to be critical for the evaluation and appropriate treatment of mass lesions in patients with AIDS.
Obliteration of experimental aneurysms in dogs with isobutyl-cyanoacrylate
Authors: Debrun Gerard M. , Varsos Vassilis , Liszczak Theodore M. , Davis Kenneth R. , Heros Roberto S. , Zervas Nicholas T.
Published: May 2009

✓ Experimental cervical carotid aneurysms in dogs are obliterated with isobutyl-cyanoacrylate (IBCA) injected under direct vision into the aneurysm. Reflux of IBCA into the artery was prevented by inflating either a latex or a Silastic balloon in the carotid artery at the level of the neck of the aneurysm. This balloon was introduced through a catheter advanced into the common carotid artery by femoral catheterization. The Silastic balloon was found to be much more effective than the latex balloon in preventing spillage of IBCA into the lumen.
Intracranial vessels lack vasa vasorum
Authors: Clower Ben R. , Sullivan David M. , Smith Robert R.
Published: May 2009

✓ A micro-corrosion technique was used to demonstrate an extensive vasa vasorum network in extracranial vessels but did not reveal this system in intracranial vessels of comparable size in three species of animals. The absence of a vasa vasorum network in cerebral vessels may result in a higher level of susceptibility to periarterial abnormalities, such as cerebral vasospasm secondary to subarachnoid hemorrhage.
Pre- and postoperative changes in serum myelin basic protein immunoreactivity in neurosurgical patients
Authors: Hoyle Nicholas R. , Seeldrayers Pierrette A. , Moussa Abdel H. , Paul Elizabeth A. , Thomas David G. T.
Published: May 2009

✓ In 44 patients undergoing neurosurgical procedures for intracranial tumors, subarachnoid hemorrhage, or spinal and peripheral nerve lesions, serum myelin basic protein (MBP) immunoreactivity was measured preoperatively and serially in the first 10 postoperative days. The double-antibody radioimmunoassay method was used, with a detection limit of 2.5 ng/ml in serum. Clinical evaluation was carried out at admission and on successive days during the period of neurosurgical management; outcome was assessed later. In the early postoperative phase, there was a fall in MBP immunoreactivity in all groups of patients. In the groups with intracranial tumor and subarachnoid hemorrhage, there was a subsequent rise in MBP immunoreactivity before the end of the 10-day period, which was not found in the group with spinal and peripheral nerve lesions.
Computerized tomography of cranial sutures
Authors: Furuya Yoshimi , Edwards Michael S. B. , Alpers Charles E. , Tress Brian M. , Ousterhout Douglas K. , Norman David
Published: May 2009

✓ Knowledge of normal suture anatomy and development is vital in order to understand abnormal suture development and to be able to distinguish sutures radiographically from normal anatomical structures and possible skull fractures. The anatomy of the sutures and synchrondroses of 150 normal pediatric and adult patients was studied using high-resolution computerized tomography scanning. Sutures of both the calvaria and skull base were most accurately identified in axial and coronal high-resolution thin-section scans when bone window algorithms were used. Developmental changes of the sutures and synchodroses, the inner and outer tables, and the diploic space were all well delineated. Vault sutures could be identified routinely in children, but their presence in adults varied considerably. With increasing age, parasutural sclerosis developed and sutures were more closely apposed.
Mechanical brain injury: the sympathoadrenal response
Authors: Rosner Michael J. , Newsome Heber H. , Becker Donald P.
Published: May 2009

✓ Catecholamine release was studied in cats as a function of injury severity in the fluid-percussion model of brain injury. Hyperglycemia was also studied as a function of catecholamine response and injury severity. Epinephrine (E) and norepinephrine (NE) increased as a function of injury. This increase was maximal at about a 3.0-atmosphere (atm) injury level and amounted to a 500-fold increase for E and 100-fold increase for NE. Both catecholamines increased maximally by 10 seconds postinjury. Glucose increased to about 350% of baseline at 500 seconds postinjury and also increased as a function of injury severity. Results suggested that the sympathoadrenal discharge was capable of a graded response which was maximal at about 3.0 atm. Associated with this increase were hypertension, bradyarrhythmias, tachyarrhythmias, and hyperglycemia.
The kallikrein-kinin system as mediator in vasogenic brain edema
Authors: Unterberg Andreas , Baethmann Alexander J.
Published: May 2009

✓ Plasma and bradykinin were perfused into the ventricular system of mongrel dogs to investigate whether either or both induce brain edema. Formation of cerebral edema was determined by measurement of cerebral water and electrolytes in periventricular white matter, cerebral cortex, and caudate nucleus. The response of cerebral tissue to exposure to bradykinin or to plasma, as a carrier of kininogens, was analyzed by assessment of the perfusate composition after ventricle passage. The authors report that cerebral administration of bradykinin induces cerebral edema. Ventricular perfusion with plasma also led to an increase of cerebral water content which was restricted to the white matter, but involved all brain tissue areas, if bradykinin was used. Ventricular perfusion with plasma was associated with consumption of the kinin precursor (kininogens) indicative of formation of kinins. Significant consumption of the precursor was found in five out of nine animals subjected to plasma perfusion of the ventricular system. In these animals a close correlation between the increase of white matter water content and kininogen-consumption as a measure of kinin-formation was obtained. Marked kinin-degrading activity was observed during ventricular perfusion with bradykinin as concluded from a considerable decrease of bradykinin concentration in the cisternal effluent compared to the inflowing perfusate concentration. Ventricular perfusion with plasma was associated with a decrease of K+ clearance capacity with continued duration, and in two animals with a release of glutamate into the plasma perfusate, suggesting an involvement of cytotoxic mechanisms.

These findings provide support for the hypothesis of a mediator function of the kallikrein-kinin (KK) system in vasogenic brain edema. The next question that needs to be answered to complete the picture — does spontaneous activation of the KK system occur in conditions leading to vasogenic edema? — is studied in a subsequent report.
The kallikrein-kinin system as mediator in vasogenic brain edema
Authors: Maier-Hauff Klaus , Baethmann Alexander J. , Lange Manfred , Schürer Ludwig , Unterberg Andreas
Published: May 2009

✓ Vasogenic edema was induced in mongrel cats by cold injury to study uptake and activation of the plasma-kallikrein-kinin system in central nervous system (CNS) tissue. A method was developed for quantitative assessment of kinin formation in affected brain tissue areas. Gross disruption of the blood-brain barrier by focal trauma causes marked penetration of plasma kininogens into necrotic and edematous brain tissue. Moreover, the kallikrein-kinin (KK) system was activated in both necrotic and perifocal edematous areas, and was markedly enhanced by additional cerebral ischemia. Formation of kinins in necrotic brain tissue led to consumption of approximately 60% to 80% of the amount of kininogens being taken up. In perifocal edematous tissue, formation of kinins was less pronounced, or even absent. However, if cerebral ischemia evolved after severe intracranial hypertension, kinins were also formed in the perifocal edematous brain. The intravascular origin of kininogens found in pathological tissue areas secondary to injury was deduced from the observation that cerebral tissue of the contralateral hemisphere with an intact blood-brain barrier had no measurable quantities of kininogens. Consumption of plasma kininogens or formation of kinins were assessed as the difference of the total amount of plasma kininogens taken up into the tissue minus the amount of kininogens found in the brain at postmortem examination.

The data indicate that uptake and activation of the plasma-KK system might occur under all pathological conditions in which blood-brain barrier damage permits cerebral penetration of plasma proteins, such as with cerebral contusion, focal ischemia, and tumors. The potent pathophysiological mechanisms induced by kinins in CNS tissue, such as formation of brain edema, microcirculatory dysfunction, and enhancement of blood-brain barrier permeability, together with their formation in focal and perifocal pathological brain tissue, provide further support for a mediator function of the KK system. Methods that specifically interfere with the formation of kinins in damaged brain should therefore be expected to attenuate vasogenic edema.