bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebral arteriovenous malformations
Authors: Luessenhop Alfred J. , Rosa Louis 
Published: May 2009

✓ To address the problems of surgical risk versus natural risk associated with cerebral arteriovenous malformations (AVM's), and the role of the intravascular operative approach, the authors have assessed a 20-year experience with 450 patients. Results of direct surgery in 90 patients indicate that for the smaller AVM's (Grades I and II), mortality and morbidity rates are lower than a reasonably projected natural risk. Hence, these patients are candidates for surgery in most instances. However, for more extensive AVM's (Grades III and IV), consideration of anticipated future years of exposure to natural risk and the location of the AVM in the brain are necessary for determining operability. In general, neither seizures nor incipient focal neurological dysfunction alone are indications for surgery, and the risks of disability or death from hemorrhage after the fifth decade of life are probably less than the surgical risks by present operative techniques. Considering the usual age of patients at the time of diagnosis, it is estimated that surgical risk is currently less than the natural risk for about 65% to 70% of all AVM patients.
The categories of AVM's in which the angiographic effectiveness of the intravascular approach is the greatest correspond to the same categories of AVM's that can be surgically removed with low risk. The intravascular approach is most useful for management of large AVM's causing progressive neurological dysfunction or as a preliminary step to surgery in selected cases in which access to major feeding arteries is difficult. The authors believe that the future of the intravascular approach should be directed toward transforming large inoperable AVM's into operable ones, but that the overall capability for this with acceptable risk is uncertain at present.
Microsurgical anatomy of the recurrent artery of Heubner
Authors: Gomes Francisco , Dujovny Manuel , Umansky Felix , Ausman James I. , Diaz Fernando G. , Ray William J. , Mirchandani Haresh G. 
Published: May 2009

✓ The recurrent arteries of Heubner were studied in 30 unfixed human brains (60 hemispheres) obtained from routine autopsies of individuals with a mean age of 34 years. The arteries were injected with tinted polyester resin via cannulation of the internal carotid arteries, and dissected under microscopic magnification. The recurrent artery of Heubner was absent in two hemispheres and double in seven hemispheres, either with a separate origin (in two) or from a common stem (in five). The artery of Heubner had a mean outer diameter of 0.8 ± 0.04 mm (range 0.3 to 1.5 mm) and a mean length of 23.4 ± 1.1 mm (range 12 to 38 mm). It originated from the A2 segment of the anterior cerebral artery (ACA) in 57% of the specimens, from the junction of the ACA and the anterior communicating artery in 35%, and from the A1 segment of the ACA in 8%.
Three types of recurrent courses were observed. In the Type I or superior course, seen in 41 (63%) of the 65 arteries, the artery followed the superior wall of the A1 segment of the ACA. In the Type II or anterior course, the arteries found in 22 (34%) of specimens maintained a rostral position in relation to the A1 segment. In the Type III or posterior course, taken by two (3%) arteries, a posterior course of the vessel in the anterior perforated substance was found. The branching pattern was identified down to a range of 100 to 200 µ, and the average number of branches was 6.5 ± 0.4 (range 3 to 12). Four groups of branches were observed. The olfactory group was represented in 91% by a single olfactory branch, with a mean outer diameter of 0.3 ± 0.03 mm. On average, 1.9 ± 0.27 frontal branches were found with a mean diameter of 0.13 ± 0.01 mm. The branches penetrating the anterior perforated substance had a larger outer diameter (mean 0.4 ± 0.03 mm) with an average number of 2.5 ± 0.2 branches. The Sylvian fissure branches were more numerous (mean 3 ± 0.3) with a mean outer diameter of 0.4 ± 0.03 mm. The point of penetration of the main trunk was found to be constant at the level of the lateral perforated substance-medial Sylvian fissure in 85% of the cases.
This report emphasizes the advantages of the intravascular casting resin injection technique in unfixed human brains over other conventional methods. It also describes the application of these anatomic data to the surgical strategy for the anterior circle of Willis, including the possible use of the recurrent artery of Heubner for microvascular reconstructive procedures.
The use of greater omentum vascularized free flaps for neurosurgical disorders requiring reconstruction
Authors: Barrow Daniel L. , Nahai Foad , Tindall George T. 
Published: May 2009

✓ The heterotopic transfer of composite tissue, with microvascular anastomosis of an arterial supply and venous drainage to locally existing vessels, has received considerable attention in the plastic surgical literature. The use of latissimus dorsi musculocutaneous free flaps has been reported in the repair of large defects of the scalp, cranium, and dura following resection of invasive neoplasms or trauma. When the defect involves primarily subcutaneous tissue loss resulting in abnormal contour, omental free flaps provide effective coverage and restoration of contour. In addition, the inherent capability of the omentum to combat infection and form an ideal bed for the establishment of skin or bone grafts provides further indications for its use.
The authors have used omental free flaps in nine cases to reconstruct gunshot wounds of the head, orbit, and face, heal chronic cavitating frontal sinus infections, form a base over exposed dura for reconstruction of the skull with rib grafts, and cover large defects after resection of invasive tumors or infected scalp. These wounds of neurosurgical interest were reconstructed with acceptable structural and aesthetic results. The indications, surgical techniques, results, alternative procedures, and potential complications of this procedure are discussed. The authors believe that omental free flaps should be considered an option in the armamentarium of reconstructive approaches for skull, dural, scalp, orbital, and facial wounds.
Origin and evolution of plateau waves
Authors: Rosner Michael J. , Becker Donald P. 
Published: May 2009

✓ Laboratory observations made in cats with fluid-percussion head injuries have suggested that plateau waves or Lundberg “A-waves” are not independent of systemic circulatory events. Four distinct phases in the evolution of the plateau wave have been identified, and each related to a circulatory change in a causal manner. The first phase is the premonitory drift phase where intracranial pressure (ICP) gradually increases prior to the plateau proper. This phase is caused by a slow gradual decline in systemic arterial blood pressure (SABP) which increases ICP by autoregulatory vasodilation and reduces cerebral perfusion pressure (CPP) to a range of 70 to 80 mm Hg. The second phase is the plateau phase initiated at a CPP of about 70 to 80 mm Hg, and is characterized by a rapid increase in ICP as CPP falls further to 40 to 50 mm Hg. The plateau lasts as long as the CPP remains stable and above ischemic levels. The third phase is the ischemic response, characterized by CPP being returned toward normal by increases in SABP in response to very low CPP's. The fourth phase is the resolution, characterized by a rapid decline in the ICP to baseline levels with stabilization of the SABP and CPP, and is best explained by autoregulatory vasoconstriction.
Plateau waves appear to occur as the result of intact or mostly intact autoregulation responding to changes in CPP. The series of events that follow are best explained by what is known of normal autoregulation; the various properties of plateau waves are viewed and explained as the expected and logical consequences of an unstable CPP acting upon a generally intact cerebrovascular bed in the face of elevated ICP and decreased compliance.
Effect of phenytoin and corticosteroids on seizures and lipid peroxidation in experimental posttraumatic epilepsy
Authors: Willmore L. James , Triggs William J. 
Published: May 2009

✓ Head trauma, intracerebral hematoma formation, and hemorrhagic cerebral infarction cause extravasation of the intravascular contents, red blood cell (RBC) hemolysis, hemosiderin deposition within the neuropil, and an increased incidence of epilepsy. Reports conflict regarding the efficacy of the administration of prophylactic anticonvulsant drugs to head-injured patients to prevent the development of posttraumatic epilepsy. In this study, rats received a 10-µl injection of 100 mM FeCl2 at a depth of 1.8 mm into the isocortex, or an equal volume of saline. Rats were then treated with 30 mg/kg methylprednisolone (MPS), 90 mg/kg MPS, 100 mg/kg phenytoin, or with an equal volume of propylene glycol. Behavioral or electroencephalographic (EEG) seizures occurred in all control-treated iron-injected rats within 93 ± 6 minutes of injection. Brain injury responses as measured by the occurrence of fluorescent product formation from iron-induced lipid peroxidation showed 6.6 ± 0.8 units/gm in the saline-injected animals, and 16.7 ± 2.5 units/gm in the control-treated iron-injected rats. Of the 90-mg/kg MPS-treated rats, 8% had seizures; fluorescence in those animals was 5.7 ± 0.5 units/gm. Phenytoin treatment prevented the occurrence of convulsive and EEG seizures; however, lipid peroxidation was unaffected (16.5 ± 4.1 units/gm).
If posttraumatic epilepsy develops because of RBC extravasation, hemolysis, parenchymal deposition of heme compounds, and initiation of lipid peroxidation, then treatments designed to prevent peroxidation may be more effective for epilepsy prophylaxis than administration of anticonvulsant drugs that mask convulsive seizures while biochemical brain injury continues.
Comparison of sodium thiopental and methohexital for high-dose barbiturate anesthesia
Authors: Boarini David J. , Kassell Neal F. , Coester Hans C. 
Published: May 2009

✓ High-dose sodium thiopental is frequently used in neuroanesthesia. The authors performed a study to compare a shorter-acting barbiturate, methohexital, to sodium thiopental in producing high-dose barbiturate anesthesia. In two groups of five mongrel dogs each, regional cerebral blood flow (CBF) was determined using the radioactive-microsphere technique, and cardiovascular parameters were measured before, during, and 1 hour after a 1½hour period of deep barbiturate anesthesia with either sodium thiopental or methohexital. Doses of the barbiturates were adjusted to produce electroencephalogram burst suppression of greater than 30 seconds.
Both agents produced a similar degree of cardiac depression, reduction in CBF, and decrease in cerebral metabolic rate of oxygen (CMRO2). Changes in cerebral and peripheral vascular resistance indicated that methohexital caused less vasoconstriction than sodium thiopental. When the barbiturate infusions were discontinued, CMRO2 and CBF returned more rapidly toward control values in the methohexital group than in the thiopental group. The more rapid recovery time and decrease in cerebral vascular resistance with methohexital suggest that it may have some advantage over sodium thiopental during certain neurosurgical procedures.
The contribution of brain injury to the overall injury severity of brain-injured patients
Authors: Fife Daniel , Jagger Janine 
Published: May 2009

✓ Several recent population-based studies of the incidence of head injury have identified cases by screening hospitalized patients. This method assumes a close relationship between severity of head injury and overall injury severity, since it is the latter that determines hospital admission. Thus, a patient whose overall injury severity is high will be admitted to the hospital regardless of the degree of his head injury. Similarly, since a patient's outcome status after treatment depends on his response to all his injuries, studies of the prognosis of various types of head injury also assume a close relationship between head injury severity and overall injury severity.
The present study examines the relationship between brain injury severity and overall injury severity in a series of hospitalized head-injured patients with evidence of actual or probable brain trauma. Among these patients, brain injury severity was closely related to overall injury severity. Head injury severity and head and neck injury severity were also closely related to overall injury severity. For all other body regions, injury severity was not closely related to overall injury severity in this group of patients.
Intracranial venous sinus hypertension: cause or consequence of hydrocephalus in infants?
Authors: Sainte-Rose Christian , LaCombe Jacques , Pierre-Kahn Alain , Renier Dominique , Hirsch Jean-François 
Published: May 2009

✓ From a previous study of achondroplasia as well as from the observation of patients with hydrocephalus associated with craniostenosis, the authors have concluded that an increased superior sagittal sinus venous pressure (SSVP) could be the cause of the enlarged ventricles. However, other workers have demonstrated that an increased SSVP could be the consequence of increased intracranial pressure (ICP). Therefore, the authors undertook a study to determine if there was a physiological test that could distinguish between rare instances of increased SSVP caused by structural and irreversible narrowing of the sinus and those caused by increased ICP.
In 20 hydrocephalic infants and children, pressure was simultaneously measured in the lateral ventricle, the superior sagittal sinus, and the jugular vein. Stable baseline pressures were recorded, as well as the variations observed after the withdrawal of an amount of cerebrospinal fluid (CSF) sufficient to lower ICP to zero. Similar recordings were taken after reinjection of an equal quantity of CSF. In all of the patients, SSVP was increased, but not as much as the ICP. In the cases of hydrocephalus without any associated cranial malformation, and therefore without any likely anatomical interruption of the sinus, CSF withdrawal induced a simultaneous decrease of ICP and SSVP. However, whereas ICP could be lowered to zero, SSVP never fell below the jugular venous pressure, which remained stable (around 5 mm Hg) throughout the recording session. Results were different when sinography demonstrated an anatomical interruption of the sinus, as in cases of hydrocephalus associated with achondroplasia or craniostenosis. In these cases, although ICP was normally lowered by CSF withdrawal, SSVP remained nearly unchanged, usually greater than the jugular venous pressure.
The present study demonstrated that SSVP recording during ICP variations induced by CSF withdrawal permits differentiation between a reversible collapse of the sigmoid sinus due to increased ICP and a fixed obstructive lesion of the sinuses. Based upon this test and the results of sinography, the authors inserted a venous bypass between the lateral sinus and a jugular vein in three patients.
Infantile acute subdural hematoma
Authors: Aoki Nobuhiko , Masuzawa Hideaki 
Published: May 2009

✓ Twenty-six cases of infantile acute subdural hematoma treated between 1972 and 1983 were reviewed. The series was limited to infants with acute subdural hematoma apparently due to minor head trauma without loss of consciousness, and not associated with cerebral contusion. Twenty-three of the patients were boys, and three were girls, showing a clear male predominance. The patients ranged in age between 3 and 13 months, with an average age of 8.1 months, the majority of patients being between 7 and 10 months old. Most of the patients were brought to the hospital because of generalized tonic convulsion which developed soon after minor head trauma, and all patients had retinal and preretinal hemorrhage. The cases were graded into mild, intermediate, and fulminant types, mainly on the basis of the level of consciousness and motor weakness. Treatment for fulminant cases was emergency craniotomy, and that for mild cases was subdural tapping alone. For intermediate cases, craniotomy or subdural tapping was selected according to the contents of the hematoma. The follow-up results included death in two cases, mild physical retardation in one case, and epilepsy in one case. The remaining 23 patients showed normal development.
The relationship between computerized tomography (CT) findings and clinical grading was analyzed. Because some mild and intermediate cases could be missed on CT, the importance of noting the characteristic clinical course and of funduscopic examination is stressed.
The Dandy-Walker malformation
Authors: Hirsch Jean-François , Pierre-Kahn Alain , Renier Dominique , Sainte-Rose Christian , Hoppe-Hirsch Elizabeth 
Published: May 2009

✓ Forty cases of Dandy-Walker malformation referred to the Hôpital Necker Enfants-Malades between 1969 and 1982 have been reviewed. The incidence of the malformation in hydrocephalus was 2.4%. There was a slight, statistically insignificant, female prevalence.
Hydrocephalus should not be included in the definition of the syndrome. In 80% of the cases, it was actually a post-natal complication of the malformation and most often developed within 3 months after birth. In 80% of the cases, a communication, although insufficient, was found between the dilated 4th ventricle and the subarachnoid space. Since this communication is probably established through the foramina of Luschka, the definition of the Dandy-Walker malformation should only include atresia of the foramen of Magendie. Associated brain and systemic malformations were numerous. Among facial anomalies, facial angiomas were found in 10% of our cases. The association of facial and cardiovascular anomalies favors the hypothesis that the onset of the malformation occurs between the formation and the migration of the cells of the neural crest (that is, between the 3rd and the 4th post-ovulatory week, earlier than previously thought).
Except in selected patients, membrane excision has a high rate of failure and should be abandoned. Cystperitoneal shunting avoids the risk of an entrapped fourth ventricle and is presently the best surgical procedure. The overall mortality in this series was 12.5%. Intelligence quotients were over 80 in 60% of the patients. Other studies will be necessary to understand why the communication between the fourth ventricle and the subarachnoid spaces, sufficient in utero, usually becomes insufficient for a normal cerebrospinal fluid (CSF) circulation in the first months following birth. Two hypotheses are discussed: a change in CSF circulation, or bleeding in the dilated fourth ventricle during delivery.
Surgical treatment of syringomyelia
Authors: Barbaro Nicholas M. , Wilson Charles B. , Gutin Philip H. , Edwards Michael S. B. 
Published: May 2009

✓ The authors reviewed the clinical findings, radiological evaluation, and operative therapy of 39 patients with syringomyelia. Syringoperitoneal (SP) shunting was used in 15 patients and other procedures were used in 24 patients. Follow-up periods ranged from 1½ to 12 years. During the period of this study, metrizamide myelography in conjunction with early and delayed computerized tomography scanning replaced all other diagnostic procedures in patients with syringomyelia. Preoperative accuracy for the two procedures was 87%.
The most common symptoms were weakness (79%), sensory loss (67%), pain (38%), and leg stiffness (28%). Surgery was most effective in stabilizing or alleviating pain (100%), sensory loss (81%), and weakness (74%); spasticity, headache, and bowel or bladder dysfunction were less likely to be reversed. Approximately 80% of patients with idiopathic and posttraumatic syringomyelia and 70% of those with arachnoiditis improved or stabilized. Better results were obtained in patients with less severe neurological deficits, suggesting the need for early operative intervention. A higher percentage of patients had neurological improvement with SP shunting than with any other procedure, especially when SP shunting was the first operation performed. Patients treated with SP shunts also had the highest complication rate, most often shunt malfunction. These results indicate that SP shunting is effective in reversing or arresting neurological deterioration in patients with syringomyelia.
Pathways for orofacial pain sensation in the trigeminal brain-stem nuclear complex of the Macaque monkey
Authors: Young Ronald F. , Ferryman Kent M. 
Published: May 2009

✓ Eleven Macaque monkeys underwent a variety of lesions in the trigeminal afferent system; namely, tractotomy, rhizotomy, and radiofrequency destruction of various components of the bulbospinal trigeminal nuclear complex. Behavioral responses were evaluated before and after the lesions using a quantitative paradigm which measured lever-pressing in response to electrical stimulation of the dental pulp or facial skin, and by assessing adversive responses to facial cutaneous and intraoral pin-scratch.
Thresholds for lever-pressing in response to cutaneous facial stimulation were elevated by tractotomy, elevated further by a combination of tractotomy and rhizotomy of the seventh, ninth, and 10th cranial nerves and cervical dorsal roots C1–3, and maximally elevated by complete radiofrequency destruction of the trigeminal nucleus caudalis. These lesions also abolished adversive responses to cutaneous facial pin-scratch. None of these lesion combinations, however, altered lever-pressing responses to dental pulp stimulation. Radiofrequency destruction of the trigeminal nuclei principalis, oralis, and interpolaris caused elevations of lever-pressing thresholds in response to dental pulp stimulation, and also smaller but statistically significant elevations on cutaneous electrical stimulation. Mild reductions in adversive responses to cutaneous pin-scratch were also produced by these rostral nuclear lesions, suggesting analgesia.
The experiments suggest that primary afferent fibers for dental pain perception travel only in the trigeminal nerve and that these fibers relay via the trigeminal brain-stem nuclei principalis, oralis, and interpolaris. Primary afferent fibers for cutaneous facial pain perception travel in the trigeminal, facial, glossopharyngeal, and vagus nerves, and the upper cervical dorsal and ventral roots, and these afferents relay mainly in the trigeminal nucleus caudalis.