bluuebunny/crossref_metadata_2025 huggingface dataset:
Complications following chemonucleolysis with collagenase
Authors: Artigas Juan , Brock Mario , Mayer Heinz-Michael
Published: May 2009

✓ Lumbar disc tissue from eight patients previously submitted to unsuccessful chemonucleolysis with collagenase was studied by light and scanning electron microscopy (SEM). Similar material from eight patients subjected to primary disc surgery served as control. The control discs revealed the characteristic signs of degeneration of collagen tissue, microcystic areas, and giant chondromas. However, the anulus fibrosus and the end-plates remained intact. Following chemonucleolysis with collagenase, “digestion” of the nucleus pulposus, the anulus fibrosus, and extensive damage to the end-plates, bone, ligaments, and epidural fat were seen.
An anterior surgical approach to the upper thoracic vertebrae
Authors: Sundaresan Narayan , Shah Jatin , Foley Kathleen M. , Rosen Gerald
Published: May 2009

✓ Of the various anterior surgical approaches to the spine, exposure of the upper two thoracic vertebrae remains the most challenging. An operative approach to this region is described. The major features include resection of a portion of the clavicle and the manubrium sterni. Following resection of the tumor and involved vertebra, anterior fusion is performed using the clavicle as a strut graft. Immediate stabilization may also be achieved with methyl methacrylate replacement of the vertebral bodies. The operation is well tolerated, and requires minimal postoperative immobilization. The clinical presentation, radiological features, and results of treatment in a series of seven patients operated on during a 2-year period are presented.
Effect of mannitol on ICP and CBF and correlation with pressure autoregulation in severely head-injured patients
Authors: Muizelaar J. Paul , Lutz Harry A. , Becker Donald P.
Published: May 2009

✓ In a previous paper, the authors showed that mannitol causes cerebral vasoconstriction in response to blood viscosity decreases in cats. The present paper describes the changes in intracranial pressure (ICP) and cerebral blood flow (CBF) after mannitol administration in a group of severely head-injured patients with intact or defective autoregulation. The xenon-133 inhalation method was used to measure CBF. Autoregulation was tested by slowly increasing or decreasing the blood pressure by 30% and measuring CBF again. Mannitol was administered intravenously in a dose of 0.66 gm/kg; 25 minutes later, CBF and ICP were measured once again. In the group with intact autoregulation, mannitol had decreased ICP by 27.2%, but CBF remained unchanged. In the group with defective autoregulation, ICP had decreased by only 4.7%, but CBF increased 17.9%. One of the possible explanations for these findings is based on strong indications that autoregulation is mediated through alterations in the level of adenosine in response to oxygen availability changes in cerebral tissue. The decrease in blood viscosity after mannitol administration leads to an improved oxygen transport to the brain. When autoregulation is intact, more oxygen leads to decreased adenosine levels, resulting in vasoconstriction. The decrease in resistance to flow from the decreased blood viscosity is balanced by increased resistance from vasoconstriction, so that CBF remains the same. This might be called blood viscosity autoregulation of CBF, analogous to pressure autoregulation. Vasoconstriction also reduces cerebral blood volume, which enhances the effect of mannitol on ICP through dehydration of the brain. When autoregulation is not intact there is no vasoconstriction in response to increased oxygen availability; thus, CBF increases with decreased viscosity. With the lack of vasoconstriction, the effect on ICP through dehydration is not enhanced, so that the resulting decrease in ICP is much smaller. Such a mechanism explains why osmotic agents do not change CBF but decrease ICP in normal animals or patients with intact vasoconstriction, but do (temporarily) increase CBF in the absence of major ICP changes after stroke.
Resolution of brain edema in severe brain injury at controlled high and low intracranial pressures
Authors: Cao Meihong , Lisheng He , Shouzheng Sun
Published: May 2009

✓ A series of 87 patients with severe brain injury were studied. Intracranial pressure (ICP) monitoring and external ventricular drainage were used to control ICP at high and low levels. Clearance of ytterbium-169-labeled diethylenetriaminepentaacetic acid (169Yb-DTPA), Evans blue dye, and ventricular cerebrospinal fluid protein was measured at the two ICP levels over consecutive periods of 4 hours to confirm clearance of brain edema. The results support the hypothesis that brain edema is in part absorbed in the cerebrospinal fluid via transventricular flow.
Intracranial pressure variations associated with activation of the cholinoceptive pontine inhibitory area in the unanesthetized drug-free cat
Authors: Katayama Yoichi , Nakamura Toru , Becker Donald P. , Hayes Ronald L.
Published: May 2009

✓ Intracranial pressure (ICP) was recorded continuously in chronically prepared, unanesthetized cats in order to investigate the effects on ICP of the cholinergic agonist, carbamylcholine (carbachol), injected by microsyringe needles into the dorsal pontine tegmentum. As reported previously, carbachol microinjections into the medial part of the cholinoceptive pontine inhibitory area (CPIA) located ventromedially to the locus coeruleus produced a comatose state characterized by a profound unresponsiveness to external stimuli, desynchronized electroencephalograms (EEG's), and suppression of postural somatomotor and sympathetic visceromotor functions. Four of six ICP records following carbachol microinjections into the CPIA showed small but significant increases which occurred in association with these carbachol effects. Tracings of ICP increases ranged up to 3.2 mm Hg and were similar in shape to plateau waves. The start and resolution of these carbachol-induced ICP variations were closely associated with the onset and termination of EEG desynchronization and signs of reduced cervical sympathetic tone, but not with changes in systemic arterial blood pressure or arterial pCO2. Temporal associations between ICP increases, desynchronized EEG's, and signs of reduced sympathetic tone were repeatedly confirmed during recovery periods associated both with recurrent comatose states following wakefulness produced by various intensities of external stimulation and with spontaneously occurring states resembling rapid eye movement sleep. The authors infer that carbachol-induced ICP variations may be produced by increased cerebral blood volume in response to accelerated cerebral metabolism and reduced vasoconstrictor tone of cervical sympathetic nerves. The simultaneous occurrence of continuously accelerated cerebral metabolism and reduced cervical sympathetic tone can neither be seen in physiologically normal, awake organisms nor produced by other known experimental manipulations of the central nervous system. Such a paradoxical relationship appears to be a unique consequence of activity within the CPIA. These data suggest that episodic activity within the CPIA may provide at least one endogenous neural basis for plateau waves seen during certain pathological conditions such as disturbed cerebrospinal fluid (CSF) absorption or with reduced equilibrium volume of CSF space.
Coronal computerized angiotomography for the diagnosis of isodense chronic subdural hematoma
Authors: Asari Syoji , Kunishio Katsuzo , Suga Masakazu , Satoh Toru , Sunami Norio , Yamamoto Yuji , Sadamoto Kazuhiko
Published: May 2009

✓ The authors demonstrate the value of coronal computerized angiotomography for the diagnosis of and screening for isodense chronic subdural hematoma. Specific features of coronal computerized angiotomograms include 1) thick lines of high density with slight convexity; 2) lines of high density parallel with the inner table of the skull; or 3) high-density dotted lines away from the inner table. These high-density lines or dots represent the superficial cerebral veins and cortical branches of the middle cerebral artery, which have been displaced by the hematoma. When these characteristic features are revealed on noninvasive coronal computerized angiotomography, cerebral angiography may be unnecessary.
Application of the coplanar principle to dynamic epidural pressure measurements
Authors: Beck John , Schettini Alfonso , Salton Rhonda
Published: May 2009

✓ The application of the coplanar principle to dynamic epidural pressure measurements was investigated in vitro. The authors used a coplanar pressure-displacement transducer, commonly employed to measure the viscoelastic properties of brain tissue in vivo. The present studies were performed using canine dura and a specially constructed fluid-filled chamber. The accuracy of the technique was assessed by comparing the pressure in the chamber recorded by the coplanar transducer to the pressure measured by a transducer directly vented to the chamber. The results show that the coplanar principle remained valid for dynamic measurements with the transducer under a variety of conditions.
Saphenous vein patch grafts in carotid endarterectomy
Authors: Little John R. , Bryerton Bernadine S. , Furlan Anthony J.
Published: May 2009

✓ The clinical data and findings on the early postoperative intravenous digital subtraction angiograms (IVDSA's) were studied in 61 patients undergoing 70 consecutive conventional carotid endarterectomies and in 46 patients undergoing 50 consecutive carotid endarterectomies with a saphenous vein patch graft (SVPG). The IVDSA's were considered normal in 50 of 70 conventional carotid endarterectomies and in 46 of 50 carotid endarterectomies with SVPG (p = 0.004). The internal carotid artery (ICA) origin was consistently larger and had a more normal configuration after carotid endarterectomy with SVPG. Ballooning at the endarterectomy site was an uncommon finding and occurred with similar frequency in both groups; that is, after three conventional carotid endarterectomies and two carotid endarterectomies with SVPG. In the conventional group, early symptomatic thrombosis occurred in the ICA in one patient and in the common carotid artery (CCA), ICA, and external carotid artery (ECA) in two patients. Silent ICA occulusion was seen in three patients in the conventional group. There were no occlusions in the SVPG group (p = 0.04). Stenosis at the distal end of the ICA arteriotomy was found after nine conventional carotid endarterectomies, and was mild (≤ 33% reduction in the lumen) in seven patients, moderate (34% to 66%) in one, and severe (≥ 67%) in one. Mild distal ICA stenosis was seen in one case after carotid endarterectomy with a SVPG (p = 0.03). Stenosis of 33% or less was found at the proximal end of the CCA arteriotomy after two carotid endarterectomies in the conventional group and one carotid endarterectomy in the SVPG group. Four patients in the conventional group suffered a postoperative cerebral infarct and one patient in the SVPG group suffered a postoperative brain-stem infarct (p = 0.28). The authors' findings have led them to routinely use a SVPG in carotid endarterectomy.
The arrest of treated hydrocephalus in children
Authors: Johnston Ian H. , Howman-Giles Robert , Whittle Ian R.
Published: May 2009

✓ A prospective study was made of the incidence of arrest of treated non-neoplastic hydrocephalus in 30 neonates and infants over a 5-year period. Radionuclide assessment of shunt function and cerebrospinal fluid (CSF) dynamics was carried out at intervals over this period, using a method that allowed injection of the radionuclide into the ventricular system independent of the shunt apparatus. The radionuclide scanning results were correlated with computerized tomography and clinical findings. Of 24 patients still available for analysis at the end of 5 years, four patients showed restoration of CSF circulation independent of the shunt apparatus and, in three of these, the shunt has either been clipped or clipped and removed without any ill effects. Clinical details of these three patients are provided. Two initially had communicating hydrocephalus, and one had probable aqueduct stenosis.
Preservation of facial function during removal of acoustic neuromas
Authors: Møller Aage R. , Jannetta Peter J.
Published: May 2009

✓ The authors describe a modification in the way the facial nerve is stimulated electrically during operations to remove medium and large-sized (> 2 cm) acoustic tumors. This consists of monopolar stimulation with low internal impedance. Proper use of this modified stimulation technique together with acoustic monitoring of the electromyographic responses of facial muscles helps to preserve facial nerve function in patients undergoing these operations, and also decreases the duration of the operation.
Neurocutaneous melanosis with extensive intracerebral and spinal cord involvement
Authors: Faillace Walter J. , Okawara Shige-Hisa , McDonald Joseph V.
Published: May 2009

✓ Two unusual cases of neurocutaneous melanosis are presented. Both patients had congenital giant hairy nevi and both developed hydrocephalus, seizures, and myelopathy. The first patient displayed multicentric cerebral and spinal cord melanosis, as opposed to the more commonly described basilar leptomeningeal involvement. The second patient had total spinal leptomeningeal involvement, and ventriculoperitoneal shunting for hydrocephalus produced peritoneal metastasis of melanoma. An individual born with a congenital giant hairy nevus or marked generalized cutaneous pigmentation should be closely observed for the development of malignant melanoma of the nervous system.
Aplasia of the cervical internal carotid artery and malformation of the circle of Willis associated with Klippel-Trenaunay syndrome
Authors: Goldstein Steven J. , Lee Charles , Young A. Byron , Guidry George J.
Published: May 2009

✓ The authors describe the radiographic findings in a patient with Klippel-Trenaunay syndrome who also had aplasia of the left internal carotid artery and a very unusual malformation of the circle of Willis. This constellation of clinical and radiographic findings is unique and has not been previously reported in the medical literature.
Failed aneurysm surgery
Authors: Drake Charles G. , Friedman Allen H. , Peerless Sydney J.
Published: May 2009

✓ Failure to obliterate intracranial aneurysms completely during initial surgery still occurs in spite of recent technical advances. Of the 115 reoperations reported in this series, 89% of the aneurysms were obliterated, and 84% of the patients had a satisfactory outcome. Twelve patients had poor results, three (2.6%) of whom were in poor condition before reoperation.
Outcome in 60 consecutive patients treated with early aneurysm operation and intravenous nimodipine
Authors: Ljunggren Bengt , Brandt Lennart , Säveland Hans , Nilsson Per-Erik , Cronqvist Sten , Andersson Karl-Erik , Vinge Ellen
Published: May 2009

✓ Sixty consecutive patients with a ruptured supratentorial aneurysm underwent operation during the acute stage, 56 of them within 72 hours after the first bleed, one on the 4th day, and three on the 5th day. Six patients were classified preoperatively in Hunt and Hess neurological Grade I, 39 in Grade II, 11 in Grade III, and four in Grade IV or V. Nine patients had severe intracerebral hematomas, and one patient had a subdural hematoma. After the aneurysm was clipped, nimodipine was applied to the exposed arterial segments in a 2.5 × 10−5M solution for 10 minutes. Subsequently, all patients received a continuous intravenous nimodipine infusion (2 mg/hr) for 7 to 12 days, followed by oral treatment (270 mg/day). Forty-six patients (77%) made a good neurological recovery; the morbidity rate was 22%, and mortality rate 1.5%. Of the 45 patients in good condition (Grades I to II) preoperatively, 38 (84%) made a good neurological recovery. Two patients (3% of the total series) developed a typical picture of cerebral ischemic dysfunction of delayed onset with subsequent fixed neurological deficits. The results favor the opinion that early operative intervention is beneficial in patients in good condition rather than delaying surgery, and indicate that nimodipine provides an additional anti-ischemic effect. The appearance and severity of late angiographic vasospasm did not seem to be affected by nimodipine.
Sequential morphological and functional changes in kaolin-induced hydrocephalus
Authors: Gonzalez-Darder José , Barbera José , Cerda-Nicolas Miguel , Segura Dolores , Broseta Jaime , Barcia-Salorio Juan Luis
Published: May 2009

✓ An experimental model of kaolin-induced hydrocephalus in the dog was studied in order to evaluate the progress of ventricular dilatation and the communications between the ventricular system and the subarachnoid space. Skull and spine radiological studies were obtained after metrizamide intraventricular injection, and the baseline ventricular pressure and cerebral pulse pressure amplitude were measured in anesthetized animals. Intracranial compliance and resistance to drainage of cerebrospinal fluid were calculated by means of bolus injection test. Light and scanning electron microscope studies were done at different developmental stages of hydrocephalus. With these experimental parameters, two successive phases were seen: an initial acute hypertensive hydrocephalus (H1) with high resistance, low compliance, severe ependymal damage, and subependymal edema; and a late chronic normotensive hydrocephalus (H2) with little resistance increase, normal compliance, epithelial regeneration, and subependymal gliosis. Both the H1 and H2 stages showed an increase in the cerebral pulse pressure amplitude.
Use of intraoperative auditory evoked potentials to preserve hearing in unilateral acoustic neuroma removal
Authors: Ojemann Robert G. , Levine Robert A. , Montgomery William M. , McGaffigan Patricia
Published: May 2009

✓ Twenty-two patients with unilateral acoustic neuromas and preoperative speech discrimination scores of 35% or more had intraoperative monitoring of the electrocochleogram (ECoG) using a transtympanic electrode, and of the brain-stem auditory evoked potentials (BAEP's) using scalp electrodes. Rapid feedback was provided about the status of the cochlear microphonics from the hair cells of the inner ear (CM of the ECoG), the compound action potential of the auditory nerve (N-1 of the ECoG or Wave I of the BAEP's) and the potentials from the lower brain stem (Wave V of the BAEP's). All patients had total removal of the tumor. In 21, the cochlear nerve was anatomically preserved, and 20 had good postoperative facial nerve function. Correlation of tumor size with postoperative hearing was as follows: discrimination scores of more than 35% in three of four patients with 1-cm tumors, two of eight with 1.5-cm tumors, two of six with 2- to 2.5-cm tumors, and one of four with tumors of 3 cm or more. Two other patients with 1.5-cm tumors had discrimination scores of less than 35%, and one patient with a 2-cm tumor had only sound perception. In two patients, the discrimination scores improved. At the end of the operation, all patients with hearing had a detectable N-1, and, when recorded, CM. All but one patient with no hearing had lost N-1, and CM was absent or reduced. Unless Wave V was unchanged, it was a poor predictor of postoperative hearing, and its absence did not preclude preservation of good hearing.

The electrophysiological changes during each stage of the operation were analyzed and correlated with events during surgery. Areas in which there was an increased risk of loss of the potentials were determined. In some patients monitoring was unnecessary, because either there were no significant changes or the changes were abrupt and no recovery occurred. However, in other patients, monitoring alerted the surgeon to a possible problem and the method of dissection was altered. Possible mechanisms of hearing loss were suggested from the changes in the recordings.
Hemangioblastoma presenting with intraparenchymatous hemorrhage
Authors: Wakai Susumu , Inoh Satoshi , Ueda Yasuichi , Nagai Masakatsu
Published: May 2009

✓ The authors report six cases of hemangioblastoma presenting with apoplectic symptoms but with no history related to the tumor. In each case, computerized tomography disclosed an intraparenchymatous hemorrhage, which was located supratentorially in four and in the cerebellum in the remaining two. Angiography revealed an abnormal vascular blush in two cases, but no abnormal vessels or tumor blush in the other four. In all cases, a solid tumor with abnormal vessels, such as red veins and feeding arteries, was found within or adjacent to the hemorrhage at surgery. The possibility of hemangioblastoma should be kept in mind as a cause of intraparenchymatous hemorrhage, particularly subcortical. Evacuation of the hematoma should be carefully carried out, and the whole hematoma wall should be thoroughly investigated for abnormal vessels or a solid mass.
The Keith needle for sharp and blunt microdissection
Authors: Dagi T. Forcht
Published: May 2009

✓ The Keith needle mounted in a suitable handle forms an exquisitely sharp disposable blade of which the haft can easily be shaped for precise microdissection. When reversed, the eye of the needle is suitable for blunt dissection.
Saccular aneurysm associated with segmental duplication of the basilar artery
Authors: Black Samuel P. W. , Ansbacher Linda E.
Published: May 2009

✓ Saccular aneurysm associated with segmental duplication (also called “fenestration”) of the basilar artery is an anomaly that results from an embryonic fault. Reports of the treatment of the aneurysmal component have only recently appeared in the neurosurgical literature, and little has been written on the morphology of this anomaly. This study answers the need for information about its structure to the extent permitted by the examination of a single specimen.

The specimen was obtained at postmortem examination. A cast of its interior features was made with a synthetic rubber. After the cast was removed, the entire anomaly was serially sectioned for histological study. Defects in the wall of the basilar artery were seen microscopically at each end of the fenestration. At the extensive proximal defect, a saccular aneurysm arose that bulged into the window between the two limbs of the segmental duplication and also presented dorsally and ventrally. It had fatally ruptured. The manner in which the fenestration was formed by intraluminal septa was also revealed.
The prognosis in subarachnoid hemorrhage of unknown etiology
Authors: Eskesen Vagn , Sørensen Ebbe B. , Rosenørn Jarl , Schmidt Kaare
Published: May 2009

✓ The mortality rate, risk of rebleeding, relevant subjective and objective symptoms, and daily functional capacity after a verified subarachnoid hemorrhage (SAH) of unknown etiology were evaluated in 44 patients treated during a 5-year period (1978 to 1983). A vascular basis for the SAH had been excluded by bilateral carotid and vertebral angiography and computerized tomography. The patients were interviewed at a follow-up examination from 3 to 64 months (median 36 months) after the bleed. The results revealed a 5% mortality rate and a 7% risk of rebleeding. Persisting headache and fatigue were found in 40% of patients, 29% had mild demential symptoms, and 5% had persisting and severe objective neurological symptoms. None had developed epilepsy. A normal daily functional capacity was enjoyed by 84%, while 14% had a moderate reduction in these functions, but were independent of help from other persons. One patient (2%) was not fully assessed.
Study of the posterior circulation in moyamoya disease
Authors: Miyamoto Susumu , Kikuchi Haruhiko , Karasawa Jun , Nagata Izumi , Ikota Toshio , Takeuchi Shigekazu
Published: May 2009

✓ Eighty-two cases of cerebrovascular moyamoya disease were studied by cerebral angiography and computerized tomography. Occlusive lesions were demonstrated not only in the anterior circulation but also in the posterior circulation, and they were associated with the development of an abnormal vascular network (moyamoya vessels). Although occlusive lesions do occur in the vertebrobasilar system, the vertebrobasilar system also acts as a source of collateral channels to the anterior circulation in this disease.
Phase II evaluation of dibromodulcitol in the treatment of recurrent medulloblastoma, ependymoma, and malignant astrocytoma
Authors: Levin Victor A. , Edwards Michael S. B. , Gutin Philip H. , Vestnys Pamela , Fulton Dorcas , Seager Margaret , Wilson Charles B.
Published: May 2009

✓ The authors have conducted a Phase II trial to evaluate orally administered dibromodulcitol in the treatment of 40 evaluable patients with recurrent medulloblastoma, ependymoma, and malignant astrocytoma. Ten of 20 patients harboring medulloblastoma responded to therapy with a median time to tumor progression (MTP) of 40 weeks, and four of 20 patients had no sign of progression of disease 4 years after treatment was begun. The MTP for all 12 patients with ependymoma was 30 weeks. Nine of these 12 patients had stabilization of their disease with an MTP of 67 weeks; three of these 12 patients had no signs of progression for 1 to 3 years after treatment was begun. Of six patients harboring supratentorial gliomas, none responded to dibromodulcitol. Two patients, one with a primitive neuroectodermal tumor and the other with a metastatic carcinoma of the breast, had stabilization of disease for more than 4 and 2 years, respectively.
Sterile shunt malfunction
Authors: Gower David J. , Lewis Jon C. , Kelly David L.
Published: May 2009

✓ Recently, a delayed hypersensitivity reaction to silicone plastics has been demonstrated in some patients with breast and joint implants and subcutaneously injected silicone. In this study, the authors examined the internal surface of shunting systems to evaluate the cellular response to implanted silicone plastic. The distal peritoneal tubing from 20 patients with ventriculoperitoneal shunts was examined with a scanning electron microscope. Twelve tubes were removed because of documented distal shunt malfunction and eight for an elective lengthening procedure. Cultures of all tubing were negative. The catheters removed for malfunction contained a variety of cells: sometimes in clumps, sometimes associated with platelets and densely adherent to the silicone tubing wall. In several shunts, giant cells were seen with multiple foot processes adherent to the internal silicone surface. The internal surface of the tubing of two malfunctioning shunts was embedded in electron microscopy plastic and studied with transmission electron microscopy. The cells proved to be neutrophils with no evidence of silicone granules inside the cell bodies. The shunts removed for elective revision showed only a few cells, and those were never associated with platelets. There was proteinaceous material scattered on the internal surface of the tubing, but the cellular response was markedly different from that in malfunctioning shunts. The authors postulate that the findings in malfunctioning shunt tubing represent a delayed hypersensitivity to silicone similar to that seen with other types of silicone implants.
Role of surgery in hypertensive intracerebral hematoma
Authors: Kanno Tetsuo , Sano Hirotoshi , Shinomiya Youichi , Katada Kazuhiro , Nagata Junji , Hoshino Masaaki , Mitsuyama Fuyuki
Published: May 2009

✓ The indications for surgery in hypertensive intracerebral hematoma are still controversial. The reason for this may be: 1) lack of adequate and comparable data in conservative and surgical therapy from the same institution; 2) lack of adequate close follow-up monitoring over an extended period of time; or 3) lack of proper classification of hematomas for comparison of results from different institutions. The authors have treated 459 cases of hypertensive intracerebral hematoma between October, 1975, and July, 1983. The hematomas have been classified according to their mode of extension on computerized tomography. The long-term outcome was assessed on the basis of activity of daily living.

Putaminal hematomas were classified as mild, moderate, severe, and very severe. In general, there was no significant difference in outcome between the surgical and nonsurgical cases; however, the outcome in the moderate and severe hematomas was found to be a little better for the surgical cases in some restricted areas. Thalamic and pontine hemorrhages were classified as mild, moderate, or severe. If the hematoma is localized to the thalamus or pons, and if it extends to the midbrain, there is no indication for surgery; however, in patients with moderate hematomas, the prognosis showed a variable outcome, and the indications for surgery were questionable. In cerebellar hematomas, the authors propose that even a hematoma with a diameter greater than 3 cm might show a good outcome with nonsurgical therapy.
Distribution of hematoporphyrin derivative in the rat 9L gliosarcoma brain tumor analyzed by digital video fluorescence microscopy
Authors: Boggan James E. , Walter Robert , Edwards Michael S. B. , Borcich Janis K. , Davis Richard L. , Koonce Michael , Berns Michael W.
Published: May 2009

✓ A digital video fluorescence microscopy technique was used to evaluate the distribution of hematoporphyrin derivative (HPD) in the rat intracerebral 9L gliosarcoma brain-tumor model at 4, 24, 48, and 72 hours after intravenous administration of 10 mg/kg of the drug. Compared to surrounding normal brain, there was significant preferential uptake of HPD into the tumor. In sections surveyed, fluorescence reached a maximum value by 24 hours; however, only 33% to 44% of the tumor was fluorescent. In contrast, fluorescence within the surrounding normal brain was maximum at 4 hours, but was present in less than 1% of the brain tissue evaluated.

The effect of HPD sensitization to a laser light dose (633 nm) of 30 joules/sq cm delivered through the intact skull was evaluated histologically in 10 rats. A patchy coagulation necrosis, possibly corresponding to the distribution of HPD fluorescence seen within the tumor, was observed. There was evidence that photoradiation therapy (PRT) affects defective tumor vasculature and that a direct tumor cell toxicity spared normal brain tissue. Despite these findings, limited uptake of HPD in tumor and the brain adjacent to tumor may decrease the effectiveness of PRT in the 9L gliosarcoma brain-tumor model. Because of the similarity between the capillary system of the 9L tumor and human brain tumors, PRT may have a limited therapeutic effect in patients with malignant brain tumors.
Thoracic disc herniation associated with papilledema
Authors: Michowiz Shalom D. , Rappaport Harry Z. , Shaked Itzchak , Yellin Allon , Sahar Abraham
Published: May 2009

✓ The occurrence of papilledema in a patient with progressive spastic paraparesis due to herniation of the T11–12 intervertebral disc is reported. The papilledema resolved following discectomy. The association and possible pathogenetic mechanisms between spinal cord lesions and signs of raised intracranial pressure are reviewed.
Parailiac ectopic bone after Cloward procedure
Authors: Rossi Eduardo , Vaquero Jesús , Martínez Roberto
Published: May 2009

✓ A rare case of parailiac ectopic bone formation 10 years after a Cloward procedure is presented. Dystrophic calcification of a previous hematoma or deposit of bone dust were considered to be the origin of this unusual complication.
Occlusion of the great vein of Galen associated with a huge meningioma in the pineal region
Authors: Sakaki Saburo , Shiraishi Toshitaka , Takeda Sadanori , Matsuoka Kenzo , Sadamoto Kazuhiko
Published: May 2009

✓ The authors report a case in which the great vein of Galen was occluded during removal of a huge meningioma in the pineal region. The patient recovered satisfactorily without any serious neurological deficits after the operation. Preoperative angiography had shown marked stenosis of the great vein of Galen and anastomoses between the deep and the superficial venous systems. Occlusion of the great vein of Galen may be well tolerated in particular cases if this vein is already compromised.
Multiple fusiform intracranial aneurysms following curative radiation therapy for suprasellar germinoma
Authors: Azzarelli Biagio , Moore Joseph , Gilmor Richard , Muller Jans , Edwards Mary , Mealey John
Published: May 2009

✓ A 17-year-old girl died from the rupture of a large fusiform aneurysm of the terminal internal carotid artery. Autopsy revealed three other fusiform aneurysms originating from major cerebral arteries clearly within the ports of previously administered telecobalt radiation therapy. Five years prior to her death, a suprasellar germinoma was partially removed and the area was treated by radiation therapy via three ports. The original arteriograms showed a normal vascular tree. Repeat arteriograms, 3 years and 8 months before her death, demonstrated the aneurysms. The development of aneurysms following radiation damage of the arteries has been reported previously, but not in intracranial vessels.
Stereotaxic device for polar approaches in orthogonal systems
Authors: Scerrati Massimo , Fiorentino Alessandro , Fiorentino Massimo , Pola Pietro
Published: May 2009

✓ A special stereotaxic device is described which was conceived and built to integrate the peculiar orthogonal approach of the well known Talairach apparatus with a polar approach. The device is useful to reach small and deep-seated brain targets, particularly those located on or close to the midline. Its use in several different stereotaxic operations, such as thalamotomy, brain-tumor biopsy, or radiotherapy, proved its flexibility, safety, and reliability.
Management of lipomyelomeningoceles
Authors: Hoffman Harold J. , Taecholarn Chopeow , Hendrick E. Bruce , Humphreys Robin P.
Published: May 2009

✓ Ninety-seven children with lipomyelomeningoceles were operated on at the Hospital for Sick Children between January, 1960, and December, 1982. The most common factor that caused these patients to seek help was the cosmetic effect of the mass on their back. However, 22 patients had urinary incontinence and 15 patients had a deformed or weak leg. Sixty of the 97 patients were female and 37 were male. The patients presented for treatment between 6 days and 18½ years of age with a median age of 7½ months. Fifty-six patients presented before the age of 6 months and 35 of these were perfectly normal at the time of presentation. On the other hand, of the 41 patients who were brought for treatment after the age of 6 months, only 12 were normal prior to surgery. When patients were appropriately treated at an early age, with their spinal cords untethered and their dura securely closed with a dural graft, then they remained unchanged neurologically or even improved. However, when treatment was delayed or not done appropriately then they were left with significant neurological sequelae. Lipomyelomeningoceles are serious lesions which without appropriate therapy can result in gross impairment of neurological function.
Meningioma: analysis of recurrence and progression following neurosurgical resection
Authors: Mirimanoff René O. , Dosoretz Daniel E. , Linggood Rita M. , Ojemann Robert G. , Martuza Robert L.
Published: May 2009

✓ The rates of survival, tumor recurrence, and tumor progression were analyzed in 225 patients with meningioma who underwent surgery as the only treatment modality between 1962 and 1980. Patients were considered to have a recurrence if their studies verified a mass effect in spite of a complete surgical removal, whereas they were defined as having progression if, after a subtotal excision, there was clear radiological documentation of an increase in the size of their tumor. There were 168 females and 57 males (a ratio of 2.9:1), with a peak incidence of tumor occurrence in the fifth (23%), sixth (29%), and seventh (23%) decades of life. Anatomical locations were the convexity (21%), parasagittal area (17%), sphenoid ridge (16%), posterior fossa (14%), parasellar region (12%), olfactory groove (10%), spine (8%), and orbit (2%). The absolute 5-, 10-, and 15-year survival rates were 83%, 77%, and 69%, respectively.

Following a total resection, the recurrence-free rate at 5, 10, and 15 years was 93%, 80%, and 68%, respectively, at all sites. In contrast, after a subtotal resection, the progression-free rate was only 63%, 45%, and 9% during the same period (p < 0.0001). The probability of having a second operation following a total excision after 5, 10, and 15 years was 6%, 15%, and 20%, whereas after a subtotal excision the probability was 25%, 44%, and 84%, respectively (p < 0.0001). Tumor sites associated with a high percentage of total excisions had a low recurrence/progression rate. For example, 96% of convexity meningiomas were removed in toto, and the recurrence/progression rate at 5 years was only 3%. Parasellar meningiomas, with a 57% total excision rate, had a 5-year probability of recurrence/progression of 19%. Only 28% of sphenoid ridge meningiomas were totally resected, and at 5 years the probability of recurrence/progression was 34%. In patients undergoing a second resection, the probability of a third operation at 5 and 10 years was 42% and 56%, respectively. There was no difference in the recurrence/progression rates according to the patients' age or sex, or the duration of symptoms. Implications for the potential role of adjunctive medical therapy or radiation therapy for meningiomas are discussed.
CBF and time thresholds for the formation of ischemic cerebral edema, and effect of reperfusion in baboons
Authors: Bell B. A. , Symon Lindsay , Branston Neil M.
Published: May 2009

✓ Ischemic cerebral edema has been studied in 41 baboons, with regional cerebral blood flow (CBF) determined by hydrogen clearance, and edema measured by microgravimetry. A threshold of ischemia has been identified for baboon cortex and subcortical white matter, which has to be crossed before edema formation begins. This threshold is 40.5% of normal CBF in cortex, and 34.4% of normal flow in subcortical white matter. A time threshold has also been determined, and the baboon brain can withstand 30 minutes of ischemia of the middle cerebral artery without significant edema formation. Reperfusion of ischemic brain has no effect on tissue water if the ischemic flow and time thresholds have not been crossed. Reperfusion of cortex, where water has begun to accumulate, exacerbates the water accumulation in proportion to the extent of the reperfusion.

If these results are applicable to man, restoration of flow should not be attempted after an ischemic insult that reduces flow to less than 40% of normal unless it can be accomplished within 30 minutes of the insult. Provided CBF can be restored to above the 40% threshold within 30 minutes, reversal of the neurological deficit and prevention of ischemic edema can be expected.
5-Hydroxytryptamine innervation of vessels in the rat cerebral cortex
Authors: Itakura Toru , Yokote Hideyoshi , Kimura Hiroshi , Kamei Ichiro , Nakakita Kazuo , Naka Yutaka , Nakai Kunio , Imai Harumichi , Komai Norihiko
Published: May 2009

✓ The role of the central 5-hydroxytryptamine (5-HT) neuron system in cerebral microcirculation of the rat was examined by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies demonstrated 5-HT-immunoreactive nerve fibers along intraparenchymal blood vessels (arterioles, capillaries, and venules). Ultrastructural observation revealed that 5-HT-immunoreactive terminal boutons (0.3 to 1.0 µm in diameter) made contact with the basement membrane of the capillaries. After an intracerebral injection of 5,7-dihydroxytryptamine (5,7-DHT), a neurotoxin to the 5-HT neuron system, no 5-HT-immunoreactive nerve fibers were found around the injection site with immunohistochemical techniques. With the hydrogen clearance method, the 5,7-DHT-injected cortex showed no significant change in regional cerebral blood flow (rCBF) in the presence of normocapnia, but a significant increase in rCBF with hypercapnia, compared with the untreated cortex. These facts strongly suggest that the central 5-HT neuron system has an important role in carbon dioxide reactivity of the cerebral blood vessels.
Cerebrovascular reactivity in patients with ruptured intracranial aneurysms
Authors: Voldby Bo , Enevoldsen Erna M. , Jensen Finn T.
Published: May 2009

✓ The cerebral vasomotor reactivity to arterial hypotension and hypocapnia was studied in 34 patients between the 3rd and 13th day after rupture of an intracranial saccular aneurysm. Using the intra-arterial xenon-133 injection method, regional cerebral blood flow (rCBF) and cerebral metabolic rate of oxygen (CMRO2) were measured. The intraventricular pressure and cerebrospinal fluid (CSF) lactate and pH levels were determined. The degree of vasospasm was measured on angiograms taken immediately following the rCBF study. The patients were graded clinically according to the system of Hunt and Hess.

Cerebral autoregulation was intact in patients in good clinical condition, but was impaired in patients in poor clinical condition. There was a close correlation between the degree of vasospasm and the degree of autoregulatory impairment, which varied from focal disturbances to global impairment. Intracranial hypertension and CSF lactic acidosis were commonly found in association with vasoparalysis. Cerebrovascular response to hyperventilation was generally preserved, although often reduced. During hyperventilation, the cerebral perfusion pressure became elevated, and increases in CMRO2 were often found, even in patients with severe diffuse spasm and cerebral ischemia. The clinical significance of the results in relation to the treatment of delayed cerebral ischemia and to the use of intraoperative induced hypotension is discussed.
Results of neurosurgical treatment by a transsphenoidal approach in 10 patients with Nelson's syndrome
Authors: Wisławski Jerzy , Kasperlik-Załuska Anna A. , Jeske Wojciech , Migdalska Barbara , Janik Jadwiga , Załuska Jozef , Bonicki Wiesław
Published: May 2009

✓ Ten patients with Nelson's syndrome, nine women and one man, aged 22 to 61 years, were treated neurosurgically by a transsphenoidal approach. In four patients, microadenomas were found, ranging in diameter from 4 to 10 mm. Microscopically, mixed adenoma was diagnosed in six cases, basophilic adenoma in three patients, and chromophobe adenoma in one patient. The presence of argyrophilic nerve fibers in the adenoma tissue was noted in one case. The time of observation after transsphenoidal surgery ranged from 6 months to 10 years. Clinical remission was achieved in eight patients; in two of them, radiation therapy was used to complement surgical treatment. In two patients, recurrence of the pituitary neoplasm was observed; anaplasia was revealed at the second operation in one of them. Radiation therapy might be a useful adjunct to neurosurgery in Nelson's syndrome, especially in patients with anaplastic adenoma.
Anatomic variations of venous sinuses in the region of the torcular Herophili
Authors: Bisaria Krishna Kumar
Published: May 2009

✓ In this study of 110 cranial cavities from adult cadavers, the superior sagittal sinus was found to divide into two channels. In most cases, the division was associated with a dural partition. Essentially, the variations as observed in this study could be grouped into three types: Type 1 includes those specimens in which the sagittal sinus drains into one lateral sinus and the straight sinus into the other, with no connection between the two. Type 2 includes those specimens in which the superior sagittal sinuses and the straight sinus fork, and the forks from both sinuses join to form the lateral sinuses. Type 3 includes those specimens in which a confluence of sinuses exists, varying from a common pool to merely a potential confluence, depending upon the presence of pads, incomplete partitions, and complete partitions of dura mater. Rare findings previously not reported consist of double straight sinuses draining into one transverse sinus; the superior sagittal sinus dividing into three channels with two transverse sinuses on one side; a transverse sinus originating from a tentorial vein; and drainage of a tentorial vein into the confluence of sinuses.
Axonal degeneration induced by experimental noninvasive minor head injury
Authors: Jane John A. , Steward Osward , Gennarelli Thomas
Published: May 2009

✓ Minor head injury or concussion was produced in experimental animals by an acceleration-deceleration non-impact injury. The animals sustained a brief loss of consciousness and no sequelae were observed. The brains were examined at 7 days by means of the Nauta and Fink-Heimer techniques. Degenerating axons were noted in the inferior colliculus, pons, and dorsolateral medulla. Degeneration was not seen in the subcortical white matter, thus suggesting a primary brain-stem locus for concussion. These findings also suggest that, in some instances, minor head injury or concussion can be associated with organic damage to the central nervous system.
Verbal memory deficits after left temporal lobectomy for epilepsy
Authors: Ojemann George A. , Dodrill Carl B.
Published: May 2009

✓ Verbal memory deficits remain a major complication of dominant hemisphere temporal lobectomy for epilepsy. The extent of this deficit was assessed preoperatively and 1 month and 1 year postoperatively with the Wechsler Verbal Memory Scale (WMSV) in 14 adults undergoing left temporal lobectomy. Intraoperative localization of language and verbal memory was also performed by electrical stimulation mapping. The WMSV score decreased an average of 22% at 1 month (13 cases), and 11% at 1 year (10 cases), even though in the majority of cases the medial extent of the resections had been significantly modified as a result of preoperative memory changes in response to intracarotid amobarbital perfusion testing. Memory decline was greater in patients who were not seizure-free, and correlated with the lateral (but not the medial) extent of the resection. The memory deficit could be predicted intraoperatively with 80% accuracy from the relationship of the resection to sites identified by electrical stimulation mapping as essential to naming or input or storage aspects of memory. This technique was applied prospectively in two additional cases with left temporal epileptic foci and complete verbal memory loss with left hemisphere amobarbital inactivation. These resections were tailored to avoid the essential naming and memory sites; the WMSV score increased 1 month postoperatively in both cases. This study identifies a lateral cortical component for verbal memory. Sites essential for that component can be localized intraoperatively with stimulation mapping; when they are spared in a resection, verbal memory deficit following dominant hemisphere temporal lobectomy can be prevented even in high-risk cases.
Spontaneous bilateral extradural hematomas
Authors: Kuwayama Naoya , Takahashi Shinichiro , Sonobe Makoto , Sugita Kyoichi
Published: May 2009

✓ Spontaneous extradural hematomas are rare and may be caused by pericranial infections, bleeding tendencies, or vascular abnormalities of the dura mater. The authors describe a case of spontaneous bilateral extradural hematomas assumed to be caused by a bleeding tendency with hypofibrinogenemia. A brief review of the literature is reported.
Oligodendroglioma and cerebral cavernous angioma
Authors: Chee Chee Pin , Johnston Robin , Doyle David , Macpherson Peter
Published: May 2009

✓ The authors report a case of frontal lobe oligodendroglioma associated with a cavernous angioma. The patient presented with signs and symptoms of raised intracranial pressure. Computerized tomography with contrast enhancement failed to detect the vascular component. The clinical and pathological significance of the presence of this vascular malformation in an oligodendroglioma is discussed.
Neurocutaneous melanosis with hydrocephalus and syringomyelia
Authors: Leaney Barry J. , Rowe Peter W. , Klug Geoffrey L.
Published: May 2009

✓ The authors report the investigation, treatment, and progress of a unique case of neurocutaneous melanosis with syringomyelia. The suspected etiology, the pathology, and the variable clinical manifestations of this rare phakomatosis are recounted. The potential for malignant change and the possible mechanisms of syrinx development in this syndrome are discussed.