bluuebunny/crossref_metadata_2025 huggingface dataset:
Prefrontal dysfunction following unilateral posteroventral pallidotomy in Parkinson's disease
Authors: Yokoyama Tetsuo , Imamura Yoko , Sugiyama Kenji , Nishizawa Shigeru , Yokota Naoki , Ohta Seiji , Uemura Kenichi
Published: January 2008

Object

Pre- and postoperative cognitive function were evaluated in 25 patients with Parkinson's disease (PD) who underwent unilateral posteroventral pallidotomy (PVP) to clarify the effects of this operation on cognitive function.

Methods

Cognitive function was assessed before surgery and 1 month and 3 months afterward by using a battery of neuropsychological tests consisting of orientation, digit span (forward and backward), digit learning, 5-minute memory of five words, similarities, serial sevens, animal name listing, and the kana pick-out test, as well as the Japanese version of the Mini-Mental State. Preoperative evaluation revealed that patients experienced difficulties in performing the neuropsychological tasks of reasoning and abstraction, working memory of numerals, word fluency, and concept formation compared with 36 healthy volunteers (p < 0.05). A simple regression analysis showed strong relationships in a negative fashion between preoperative (r = 0.81, p = 0.002) and 1-month (r = 0.79, p = 0.0059) and 3-month (r = 0.85, p = 0.0016) postoperative gross-total scores and Hoehn and Yahr staging. Preoperative and postoperative scores at 1 month and 3 months were analyzed by analysis of variance, but only the Fisher's post hoc test revealed the source of difference. All tasks except orientation (p = 0.0292) were unchanged in the 10 patients who underwent surgery on the right side. The scores for this task at 1 month postsurgery were significantly lower (p = 0.0203) but improved to preoperative values by 3 months. In the 15 patients who underwent surgery on the left side significant differences among tasks were revealed for serial sevens (p = 0.0471) and animal naming (p = 0.0425). The scores for these tasks were significantly lower at 1 month postoperatively (p = 0.0431 for serial sevens and p = 0.0408 for animal naming), but improved by 3 months after the operation.

Conclusions

The present data revealed that cognitive dysfunction in patients with PD relates to advancement of Hoehn and Yahr stage, but PVP is not associated with significant long-lasting cognitive deficits.
Neuroendoscopic third ventriculostomy
Authors: Buxton Neil
Published: January 2008

Neuroendoscopic third ventriculostomy is becoming increasingly popular as the primary mode of therapy for patients with noncommunicating hydrocephalus. In this article the author reviews the procedure and its indications, and highlights its complications. It can, without doubt, be recommended as the first line treatment for hydrocephalus and also in cases in which shunt malfunction or infection occurs.
Endoscopic surgery for intracranial cerebrospinal fluid cyst malformations
Authors: Gangemi M. , Maiuri F. , Colella G. , Sardo L.
Published: January 2008

Endoscopic surgery represents a new and very useful modality of treatment for intracranial cysts. The authors review the cases of 19 patients with intracranial malformative CSF cysts (seven intraventricular, six paraventricular, and six arachnoid) who underwent endoscopic fenestration by using a burr-hole approach. The various endoscopic approaches and techniques of fenestration, according to the type and location of the cyst, and the causes of unsuccessful outcome are critically discussed. The authors recommend endoscopic fenestration as the treatment of choice for patients with para- and intraventricular cysts, in whom the procedure may help to avoid the microsurgical approach and shunt placement in nearly all patients. In patients with arachnoid cysts, the endoscopic procedure, although associated with a lower rate of successful outcome, may be performed as the primary procedure in most cases because it is a minimally invasive procedure; the traditional surgical treatment may be performed without additional risk in which endoscopic surgery has failed.
Increased inspired oxygen concentration as a factor in improved brain tissue oxygenation and tissue lactate levels after severe human head injury
Authors: Menzel Matthias , Doppenberg Egon M. R. , Zauner Alois , Soukup Jens , Reinert Michael M. , Bullock Ross
Published: January 2008

Object

Early impairment of cerebral blood flow in patients with severe head injury correlates with poor brain tissue O2 delivery and may be an important cause of ischemic brain damage. The purpose of this study was to measure cerebral tissue PO2, lactate, and glucose in patients after severe head injury to determine the effect of increased tissue O2 achieved by increasing the fraction of inspired oxygen (FiO2).

Methods

In addition to standard monitoring of intracranial pressure and cerebral perfusion pressure, the authors continuously measured brain tissue PO2, PCO2, pH, and temperature in 22 patients with severe head injury. Microdialysis was performed to analyze lactate and glucose levels. In one cohort of 12 patients, the PaO2) was increased to 441 ± 88 mm Hg over a period of 6 hours by raising the FiO2 from 35 ± 5% to 100% in two stages. The results were analyzed and compared with the findings in a control cohort of 12 patients who received standard respiratory therapy (mean PaO2 136.4 ± 22.1 mm Hg).

The mean brain PO2 levels increased in the O2-treated patients up to 359 ± 39% of the baseline level during the 6-hour FiO2 enhancement period, whereas the mean dialysate lactate levels decreased by 40% (p < 0.05). During this O2 enhancement period, glucose levels in brain tissue demonstrated a heterogeneous course. None of the monitored parameters in the control cohort showed significant variations during the entire observation period.

Conclusions

Markedly elevated lactate levels in brain tissue are common after severe head injury. Increasing PaO2 to higher levels than necessary to saturate hemoglobin, as performed in the O2-treated cohort, appears to improve the O2 supply in brain tissue. During the early period after severe head injury, increased lactate levels in brain tissue were reduced by increasing FiO2. This may imply a shift to aerobic metabolism.
Coexistence of two different intraspinal tumors
Authors: Glasauer Franz E. , Castiglia Gregory J. , Lifeso Robert M.
Published: January 2008

The occurrence of multiple neoplasms in the central nervous system is well documented. In von Recklinghausen's disease, patients frequently present with multiple neurofibromas and/or meningiomas at different sites within the spinal axis. However, the presence of multiple, histologically different spinal tumors in the absence of von Recklinghausen's disease is extremely rare.

The authors describe a patient with progressive paraparesis in whom an extradural, malignant lesion and a separate benign, intradural tumor of the thoracic spine were found. The histological diagnosis of the intradural tumor was a pigmented schwannoma.

On review of the literature, the authors found nine additional cases of coexisting, histologically different tumors of the spine. The majority of these tumors occurred in the thoracic spine and, not unexpectedly, intradural meningiomas and schwannomas prevailed. Except for the presumed same mesenchymal cell origin of neurinomas and meningiomas, no explanation for the coexisting, different spinal tumors could be determined.
Outcome after complex neurosurgery: the caregiver's burden is forgotten
Authors: Lang Dorothy A. , Neil-Dwyer Glenn , Garfield John
Published: January 2008

Object

The goals of this study were twofold: 1) to determine outcome, including quality of life, in patients who have undergone surgery for petroclival meningioma in which a standard skull base approach was used; and 2) to assess the impact of the patients' surgical treatment on their caregivers.

Methods

Seventeen patients (13 women and four men ranging in age from 29 to 63 years) who underwent a transpetrosal approach for a petroclival meningioma during a 5-year period were prospectively included in this study. Pre- and postoperative data including adverse events were noted. The patients were assessed at 3, 6, and 12 months postoperatively, and annually thereafter, and they completed a postoperative SF-36 questionnaire. In addition, each patient's caregiver was interviewed to determine the effect of the patient's illness on the caregiver's life and responsibilities.

Twenty-two operations were performed. A new permanent neurological deficit developed in five patients and in eight a temporary deficit or exacerbation of existing deficits occurred. Two patients underwent surgery to create a facial-hypoglossal nerve communication; five required a temporary percutaneous gastrostomy and/or tracheostomy; three required a shunt; and one underwent successful squint surgery. At 1 year postoperatively 13 patients had made a good or moderate recovery, three were severely disabled, and one had died--outcomes in keeping with other studies. By contrast, responses to the SF-36 questionnaire showed that, in all eight of its categories, between 43% and 75% of surviving patients were functioning below accepted norms. Fifty-six percent of caregivers experienced a major change in lifestyle and 38% experienced a major change with respect to their work.

Conclusions

After transpetrosal excision of a petroclival meningioma, the quality of life for the patient is worse than that indicated in surgeons' reported results. The impact on the patient's caregiver is profound--a burden perhaps not fully appreciated by the surgeon.
Treatment strategies for medulloblastoma and primitive neuroectodermal tumors
Authors: Gold Deborah R. , Packer Roger J. , Cohen Bruce H.
Published: January 2008

Medulloblastoma and primitive neuroectodermal tumors (PNETs) are the most common malignant brain tumors in children. The concern for late sequelae of neuraxis irradiation and the obligation to improve disease-free survival in children who harbor malignant brain tumors has led to the additional provision of systemic chemotherapy to standard- and reduced-dose radiotherapy, as well as to the evaluation of alternate modes of radiotherapy delivery. Analysis of evidence has suggested that chemotherapy has an impact on length of survival in children with medulloblastoma and PNETs. The question remains as to whether chemotherapy combined with reduced-dose radiotherapy provides greater benefit than standard-dose radiotherapy alone, and which subset of children the treatment most benefits. Also unanswered is the question of whether chemotherapy can serve as the primary treatment in infants with these lesions. In an attempt to help answer these questions, the authors review the major chemotherapy and radiotherapy trials for newly diagnosed patients and those with recurrent medulloblastoma and PNETs.
In vivo treatment with anti-CD44 monoclonal antibody disrupts intracerebral progression of C6 glioblastoma
Authors: Breyer Roger , Hussein Sami , Radu Dorel L. , Pütz Klaus-Martin , Gunia Sven , Hecker Hartmut , Samii Madjid , Walter Gerhard F. , Stan Alexandru C.
Published: January 2008

Glioblastoma multiforme (GBM) invasiveness is a complex process that involves recognition and attachment of GBM cells to particular extracellular matrix (ECM) molecules prior to migrating into proteolytically modified matrix and inducing angiogenesis. The CD44, which is a transmembrane adhesion molecule found on a wide variety of cells including GBM, has been suggested as the principal mediator of migration and invasion. The aim of the present study was to demonstrate whether an antibody specific to the standard form of CD44 (CD44s, 85-90 kDa) might prevent invasion and thus disrupt progression of C6 GBM in vivo.

Immunostaining demonstrated homogenous expression of CD44s on the surface of C6 GBM cells and tumors. Flow cytometric analysis demonstrated binding saturation of anti-CD44s mAb to the receptor at 1 μg/5 X 105 cells. Blocking of CD44s in vitro resulted in a dose-dependent progressive (up to 94 ± 2.7%; mean ± standard deviation [SD]) detachment of C6 cells from ECM-coated culture surfaces. Blocking of CD44s in vivo resulted in significantly reduced C6 brain tumors (3.6 ± 0.4% [SD])--measured as the quotient: tumor surface (mm2)/brain surface (mm2) X 100--as compared with untreated (19.9% ± 0.9%) or sham-treated rats (19.2 ± 1.1% to 19.3 ± 2.5% [SD]). Disruption of C6 GBM progression correlated with an improved food intake; treated rats were significantly less cachectic (166.6 ± 16.4 g [SD]) than those that were untreated (83.0 ± 2.7 g [SD]) or sham-treated (83.4 ± 1.1 g to 83.0 ± 2.2 g [SD]) rats.

The authors conclude that CD44s-targeted treatment with specific mAb may represent an effective means for preventing progression of highly invasive GBMs.
Empty sella syndrome: does it exist in children?
Authors: Ammar Ahmed , Al-Sultan Ali , Mulhim Fatma Al , Hassan Abdulla Yousef Al
Published: January 2008

The empty sella syndrome (ESS) is well documented in adults and although the same phenomenon of herniation of the arachnoid space into the enlarged sella turcica has been noted in children, it is not widely known that children suffer from this syndrome. Therefore, the aims of this paper are to increase neurosurgeons' awareness of the existence of this phenomenon in children and to add to the scant body of literature on the subject.

The authors treated 12 children, ranging in age between 2 and 8 years in whom neuroradiological studies demonstrated an enlarged sella turcica filled with cerebrospinal fluid and herniation of suprasellar and arachnoid spaces. The causes of ESS in these children were high intracranial pressure, neglected or improperly treated hydrocephalus, and suprasellar arachnoid cyst. Primary ESS was found as well. Most of the children presented with headache, abnormal body weight (the majority being underweight), and short stature. The results of hormone assays were normal in all children.

If undiagnosed and untreated, ESS in children may lead to serious consequences, including impairment of pituitary and hypothalamic function and damage to the optic chiasm. It is important to raise awareness in the neurosurgical community about the existence of ESS in children so that it can be diagnosed and treated at an early stage. A classification system for the diaphragma sellae is recapitulated.
Increased incidence and impact of nonconvulsive and convulsive seizures after traumatic brain injury as detected by continuous electroencephalographic monitoring
Authors: Vespa Paul M. , Nuwer Marc R. , Nenov Valeriy , Ronne-Engstrom Elisabeth , Hovda David A. , Bergsneider Marvin , Kelly Daniel F. , Martin Neil A. , Becker Donald P.
Published: January 2008

Object

The early pathophysiological features of traumatic brain injury observed in the intensive care unit (ICU) have been described in terms of altered cerebral blood flow, altered brain metabolism, and neurochemical excitotoxicity. Seizures occur in animal models of brain injury and in human brain injury. Previous studies of posttraumatic seizures in humans have been based principally on clinical observations without a systematic approach to electroencephalographic (EEG) recording of seizures. The purpose of this study was to determine prospectively the incidence of convulsive and nonconvulsive seizures by using continuous EEG monitoring in patients in the ICU during the initial 14 days postinjury.

Methods

Ninety-four patients with moderate-to-severe brain injuries underwent continuous EEG monitoring beginning at admission to the ICU (mean delay 9.6 ± 5.4 hours) and extending up to 14 days postinjury. Convulsive and nonconvulsive seizures occurred in 21 (22%) of the 94 patients, with six of them displaying status epilepticus. In more than half of the patients (52%) the seizures were nonconvulsive and were diagnosed on the basis of EEG studies alone. All six patients with status epilepticus died, compared with a mortality rate of 18 (24%) of 73 in the nonseizure group (p < 0.001). The patients with status epilepticus had a shorter mean length of stay (9.14 ± 5.9 days compared with 14 ± 9 days (t-test, p < 0.03). Seizures occurred despite initiation of prophylactic phenytoin on admission to the emergency room, with maintenance at mean levels of 16.6 ± 2.8 mg/dl. No differences in key prognostic factors (such as the Glasgow Coma Scale score, early hypoxemia, early hypotension, or 1-month Glasgow Outcome Scale score) were found between the patients with seizures and those without.

Conclusions

Seizures occur in more than one in five patients during the 1st week after moderate-to-severe brain injury and may play a role in the pathobiological conditions associated with brain injury.
Enhancement of graft survival and sensorimotor behavioral recovery in rats undergoing transplantation with dopaminergic cells exposed to glial cell line-derived neurotrophic factor
Authors: Mehta Vivek , Hong Murray , Spears Julian , Mendez Ivar
Published: January 2008

The goal of this study was to investigate the ability of fetal dopaminergic neurons to improve complex sensorimotor behavior.

The authors obtained ventral mesencephalic tissue from 14-day-old rat fetuses. The cells were exposed to glial cell line-derived neurotrophic factor (GDNF) prior to transplantation into rats with unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal pathway. Animals that received 400,000 cells exposed to GDNF demonstrated significant improvement in contralateral forelimb function and showed improvement in rotational behavior faster than animals that received cells not exposed to GDNF. Increasing the number of implanted cells to 800,000 exposed to GDNF did not result in any additional improvement in functional recovery.

As neural grafting procedures in the nervous system evolve and genetically engineered cells or stem cells replace fetal tissue, crucial questions about cell number and trophic regulation will need to be addressed. This study demonstrates that grafting of 400,000 cells exposed to GDNF before transplantation has a beneficial effect in the restoration of complex sensorimotor behavior.
Localization of hand motor activation in Broca's pli de passage moyen
Authors: Boling Warren , Olivier André , Bittar Richard G. , Reutens David
Published: January 2008

Object

The object of this study was to identify a reliable surface landmark for the hand motor area and to demonstrate that it corresponds to a specific structural component of the precentral gyrus.

Methods

Positron emission tomography (PET) activation studies for hand motor function were reviewed in 12 patients in whom magnetic resonance imaging results were normal. Each patient performed a hand opening and closing task. Using a computer-assisted three-dimensional reconstruction of the surface of each hemisphere studied, the relationship of the hand motor area to cortical surface landmarks was evaluated.

Conclusions

The region of hand motor activation can be reliably identified on the surface of the brain by assessing anatomical relationships to nearby structures. After identification of the central sulcus, the superior and middle frontal gyrus can be seen to arise from the precentral gyrus at a perpendicular angle. A bend or genu in the precentral gyrus is constantly seen between the superior and middle frontal gyrus, which points posteriorly (posteriorly convex). The location of hand motor function, identified using PET activation studies, is within the central sulcus at the apex of this posteriorly pointing genu. The apex of the genu of the precentral gyrus leads to a deep cortical fold connecting the pre- and postcentral gyri and elevating the floor of the central sulcus. This deep fold was described by Paul Broca as the pli de passage fronto-pariétal moyen, and the precentral bank of the pli de passage represents the anatomical substratum of hand motor function. Observers blinded to the results of the activation studies were able to identify the hand motor area reliably after instruction in using these surface landmarks.
Management of patients with normal-pressure hydrocephalus by using lumboperitoneal shunt system with the Codman Hakim programmable valve
Authors: Chang Chia-Cheng , Kuwana Nobumasa , Ito Susumu
Published: January 2008

Thirty-two patients with normal-pressure hydrocephalus were managed using the lumboperitoneal (LP) shunt system in which the Codman Hakim programmable valve was utilized. The initial opening pressure was set at 100 mm H2O in three cases, 80 mm H2O in two, 70 mm H2O in three cases, 50 mm H2O in 23, and 30 mm H2O in one case (mean pressure 57.8 mm H2O). In 12 patients the valve pressure required reprogramming. The final valve pressure was 30 mm H2O in four cases, 50 mm H2O in 19, 70 mm H2O in three, 80 mm H2O in one, 100 mm H2O in two, 130 mm H2O in one, 140 mm H2O in one, and 170 mm H2O in one case (mean 62.5 mm H2O). Lumboperitoneal shuntography was performed in five patients by injection of contrast medium into the prechamber. In two patients a shunt obstruction developed between the valve and the lumbar catheter. Complications occurred in eight patients. Low-pressure symptoms such as headache and vomiting were observed in four patients but disappeared after increasing the valve pressure. One patient, whose shunt pressure was set at 50 mm H2O developed a slight asymptomatic subdural effusion, which resolved after increasing the valve pressure to 100 mm H2O. Convulsions developed in two aged patients but were easily controlled with anticonvulsant medication. Surgery-related wound infection was observed in one patient.

The major advantage in the use of this valve is the ability to modify the pressure noninvasively. Another important advantage of the LP shunt system in which this valve is incorporated is the lower pressure of 30 mm H2O that can improve symptoms caused by underdrainage of cerebrospinal fluid.
Response of cerebral blood flow and cerebrovascular reactivity to acetazolamide in patients with dementia and idiopathic normal-pressure hydrocephalus
Authors: Chang Chia-Cheng , Kuwana Nobumasa , Ito Susumu , Ikegami Tadashi
Published: January 2008

The responses of cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to administration of acetazolamide were investigated in 16 patients with dementia and ventriculomegaly to clarify the cerebral hemodynamics in patients with idiopathic normal-pressure hydrocephalus (NPH).

The mean CBF velocity in the whole brain was measured by the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime single-photon emission computerized tomography. The CVR values were obtained from the response to administration of 500 mg of acetazolamide and calculated as the percentage of change from the baseline mean CBF value. The mean CBF value was significantly reduced (p < 0.01) in six patients with (35.2 ± 5 ml/100 g/minute) and 10 patients without (33.5 ± 2.8 ml/100 g/minute) NPH compared with the age-matched normal controls (40.8 ± 3.2 ml/100 g/minute), showing no significant difference. The CVR was significantly impaired in patients with NPH (0.8 ± 1.7%; p < 0.001), whereas in patients without NPH preserved CVR (11.3 ± 3%) was demonstrated compared with the normal controls (14.7 ± 1.1%). In patients with NPH a significantly lower CVR (p < 0.001) was shown than in those without NPH. The CVR significantly increased (p < 0.001) after placement of a shunt in patients with NPH.

Reductions in both CBF and CVR may be diagnostic indicators of NPH in patients with dementia in whom ventriculomegaly is present. In patients with dementia and idiopathic NPH both reduced CBF and extremely impaired CVR are shown. The results of the present study suggest that ischemia due to the process of NPH is responsible for the reduction of CBF and manifestation of symptoms in patients with idiopathic NPH.
Altered diffusion and perfusion in hydrocephalic rat brain: a magnetic resonance imaging analysis
Authors: Massicotte Eric M. , Buist Richard , Del Bigio Marc R.
Published: January 2008

It can be inferred from data published in the literature that brain compression occurs in the early stages of acute hydrocephalus and that drainage of extracellular waste products is impaired. The authors hypothesized that compression of the cortical extracellular compartment will alter water distribution and retard the diffusion of fluid in the hydrocephalic brain.

Using magnetic resonance imaging proton diffusion, blood perfusion, and T1 and T2 relaxation times were determined in adult rat brain prior to, and 1 and 8 days following induction of hydrocephalus by using kaolin injection. Five anatomical regions of interest were studied. The striatum, dorsal cortex, and lateral cortex were shown to exhibit decreased T2 and apparent diffusion coefficient (ADC) values but no change in perfusion. Examination of white matter demonstrated an initial decrease in ADC followed by a significant increase. The T2 relaxation times increased and perfusion decreased progressively from 1 to 8 days.

Acute experimental hydrocephalus causes compression of gray matter, perhaps associated with reduction in total water, which impairs diffusion of protons in the tissue. White matter compression and hypoperfusion precede the development of edema. These findings have importance for understanding the neurochemical changes that occur in hydrocephalic brains.
Endoscopic management of hydrocephalus secondary to tumors of the posterior third ventricle
Authors: Teo Charles , Young Ronald
Published: January 2008

Management of the obstructive hydrocephalus that accompanies tumors located in the third ventricle has traditionally involved either urgent tumor resection, with resultant ventricular decompression, or cerebrospinal fluid diversion that requires either ventriculostomy or shunt placement prior to tumor removal. Although this approach has worked well for the better part of a century, it has both short- and long-term sequelae that can possibly be avoided. Beacause a number of lesions in this area are benign or are amenable to radiotherapy, a less invasive approach to their treatment is desirable. The advances in both instrumentation and techniques of endoscopic surgery have established alternatives to the traditional treatment of third ventricular tumors and resultant hydrocephalus. The authors review the treatment of 19 patients with posterior third ventricular tumors who presented to Arkansas Children's Hospital over a 5-year period (September 1993–July 1999). In 11 patients signs and/or symptoms of hydrocephalus were demonstrated and were treated with endoscopic third ventriculostomy, additionally, a biopsy procedure, resection, or fenestration of the tumor was performed in a number of patients. Endoscopy was believed to have been of benefit in all patients, despite the eventual failure of the ventriculostomy in one patient. There were no complications in this series. The algorithm thus developed by the authors provides both a diagnostic and therapeutic pathway that may ultimately reduce the morbidity associated with the treatment of patients with posterior third ventricular lesions.
Endosaccular aneurysm occlusion with Guglielmi detachable coils for obstructive hydrocephalus caused by a large basilar tip aneurysm
Authors: Watanabe Akira , Imamura Kazuhiro , Ishii Ryoji
Published: January 2008

The authors present the case of a 60-year-old man with obstructive hydrocephalus caused by a large basilar artery tip aneurysm, in whom direct surgical clipping of the aneurysm neck was considered hazardous. After endosaccular aneurysm occlusion, his symptoms (headache, intellectual impairment, and gait disturbance) and ventricular dilation immediately improved without placement of a ventricular shunt. To the authors' knowledge, this is the first case of its kind treated solely endovascularly.
Expanding lacunae causing triventricular hydrocephalus
Authors: Mascalchi Mario , Salvi Fabrizio , Godano Umberto , Nistri Marco , Taiuti Rosanna , Tosetti Michela , Villari Natale , Calbucci Fabrio
Published: January 2008

Two patients are reported in whom the presence of triventricular hydrocephalus and aqueductal obstruction or stenosis due to multiple expanding lacunae in the mesencephalothalamic region possibly corresponds to abnormally dilated perivascular spaces. Placement of a ventriculoperitoneal cerebrospinal fluid (CSF) shunt in one patient and the performance of a third ventricle cisternotomy in the other reversed the hydrocephalic syndrome, but did not modify the complex neuroophthalmological disturbance and rubral tremor presumably related to the compressive effects of the lacunae on adjacent parenchyma. In one patient the number and size of the lacunae were increased 4 years after CSF shunt placement. A review of the literature revealed two cases in which magnetic resonance imaging demonstrated a similar, poorly understood pathological condition.
Incidence and management of subdural hematoma/hygroma with variable- and fixed-pressure differential valves: a randomized, controlled study of programmable compared with conventional valves
Authors: Carmel Peter W. , Albright A. Leland , Adelson P. David , Canady Alexa , Black Peter , Boydston William , Kneirim David , Kaufman Bruce , Walker Marion , Luciano Mark , Pollack Ian F. , Manwaring Kim , Heilbrun M. Peter , Abbott I. Richmond , Rekate Harold
Published: January 2008

Shunt systems with differential pressure valves are prone to the complications of overdrainage. A programmable valve permits adjustment of the opening pressure of the valve. In this paper the authors report the incidence of subdural fluid collections in a randomized trial of programmable compared with conventional valves, and they describe methodologies used in management of this complication.

A multiinstitutional, prospective, randomized trial of the Codman Hakim programmable valve and conventional fixed-pressure valves was undertaken. Two classes were defined: “new” and “replacement” valves. Randomization of the type of valve in each group was performed at each study site. Clinical and radiological studies were required at fixed intervals over a 104-week period. All complications were reported. The experimental valves were required to be reprogrammed after magnetic resonance imaging studies, but all other decisions regarding pressure setting were left to each investigator.

Three hundred seventy-seven patients were randomized; 194 were treated with a programmable valve and 183 with a fixed-pressure valve. The two groups were statistically similar in demographic composition, as were the “new” and “replacement” categories. The investigators made 540 valve pressure changes (five per patient; range one-41 changes). More than half of the reprogramming adjustments were made in the first 3 months postplacement; 70% were made within 6 months. More than half of all reprogramming adjustments were required in a group of 30 patients.

Four treatment modalities were observed: 1) 30% of the fluid collections resolved spontaneously (25% in the patients with programmable valves and 36.3% in those with conventional valves) and were largely found to be hygromas in infants and children; 2) four subdural fluid collections were unresolved and under observation; 3) the subdural hematoma was drained and the shunt removed (in 8.3% of patients with the programmable valve and 36.3% of those with the control valve); 4) the pressure of programmable valve was raised in 58% of patients (seven of 12), and this increase in opening pressure was a feature used by investigators to affect treatment.

There was no significant difference in the incidence of subdural fluid collections between the programmable and fixed-pressure valve treatment groups. The programmable feature provided a considerable advantage in treatment when subdural collections occurred.
Intracranial hypertension and cerebral perfusion pressure: influence on neurological deterioration and outcome in severe head injury
Authors: Juul Niels , Morris Gabrielle F. , Marshall Sharon B. , _ _ , Marshall Lawrence F.
Published: January 2008

Object

Recently, a renewed emphasis has been placed on managing severe head injury by elevating cerebral perfusion pressure (CPP), which is defined as the mean arterial pressure minus the intracranial pressure (ICP). Some authors have suggested that CPP is more important in influencing outcome than is intracranial hypertension, a hypothesis that this study was designed to investigate.

Methods

The authors examined the relative contribution of these two parameters to outcome in a series of 427 patients prospectively studied in an international, multicenter, randomized, double-blind trial of the N-methyl-D-aspartate antagonist Selfotel. Mortality rates rose from 9.6% in 292 patients who had no clinically defined episodes of neurological deterioration to 56.5% in 117 patients who suffered one or more of these episodes; 18 patients were lost to follow up. Correspondingly, favorable outcome, defined as good or moderate on the Glasgow Outcome Scale at 6 months, fell from 67.8% in patients without neurological deterioration to 29.1% in those with neurological deterioration. In patients who had clinical evidence of neurological deterioration, the relative influence of ICP and CPP on outcome was assessed. The most powerful predictor of neurological worsening was the presence of intracranial hypertension (ICP >/= 20 mm Hg) either initially or during neurological deterioration. There was no correlation with the CPP as long as the CPP was greater than 60 mm Hg.

Conclusions

Treatment protocols for the management of severe head injury should emphasize the immediate reduction of raised ICP to less than 20 mm Hg if possible. A CPP greater than 60 mm Hg appears to have little influence on the outcome of patients with severe head injury.
The importance of shunt valve position in flow characteristics of the Medtronic PS Medical Delta valve
Authors: Francel Paul C. , Stevens F. Alan , Tompkins Paul , Pollay Michael
Published: January 2008

This study was conducted to document the extent to which flow depends on valve position in relation to head-pressure reference.

Medtronic PS Medical Delta valves (contour model, performance levels 0.5, 1.0, 1.5, and 2.0) were studied in a bench test designed to evaluate flow rates with respect to valve position in relation to the head-pressure reference postion. The valves were connected to an “infinite” reservoir by the standard inlet catheter. An initial head (proximal) pressure was selected for each valve based on package insert data. The position of the inlet catheter tip was fixed at this starting head pressure, thus making the inlet catheter tip position the reference for relative head pressures on the valve assembly. When the valve body is positioned above this level, the effective head pressure is lowered, and when the valve body is positioned below this level, the effective head pressure is raised. Flow was established with the siphon control portion of the valve body located on the same horizontal level as the inlet catheter tip (the reference head pressure or “0” position). A standard silastic catheter was attached to the outlet of the valve, and its length was fixed at 50 cm for all valves (-50 cm H20). The distal end of the outlet catheter was connected to a fraction collector, and 1-minute samples (five replicates) were collected for gravimetric determination of flow rate. The valve assembly was then moved in 1-cm increments through the range of 4 cm above to 8 cm below the head-pressure reference position. Samples were collected from each position (4 cm to -8 cm) relative to the inlet catheter tip. Flow rate, in milliliters/hour, was plotted against both relative position (4 cm to -8 cm) and absolute head pressure (in centimeters of water).

Each of the valves tested was shown to have a linear relationship between flow and position relative to the inlet catheter tip (or absolute head pressure). The average increase in flow per centimeter of displacement of valve from catheter tip was 16.5 ml/hr/cm (range 14.4-17.6 ml/hr/cm). Once the inlet catheter tip is fixed in position, it serves as a pressure reference. Movement of the valve above this level results in a net decrease in effective head pressure, and movement below this position results in a net increase in effective head pressure. Thus, the positioning of shunt valves in locations different from this pressure reference position should be performed only with the knowledge that significant increases in outflow rate may occur when the valve body is positioned lower than the inlet catheter tip. This increase in outflow rate is not the result of siphoning or a defect in the antisiphon device but instead the result of a net increase in effective head pressure.
A combined study of tumor-related brain lesions by using magnetoencephalography and 1H magnetic resonance spectroscopic imaging
Authors: Kamada Kyousuke , Möller Martin , Saguer Mark , Ganslandt Oliver , Kaltenhäuser Martin , Kober Helmut , Vieth Jürgen
Published: January 2008

The purpose of this study was to localize pathological magnetic brain activities and to analyze metabolic alterations in functionally abnormal lesions by using magnetoencephalography (MEG) and 1H magnetic resonance (MR) spectroscopy in patients with brain tumors. The authors studied 10 healthy volunteers and seven patients who harbored common brain tumors, namely astrocytic tumors and meningioma. In spontaneous MEG the pathological brain activities (slow waves, fast waves, and spikes) were localized using a single equivalent dipole model. After the results of MEG and 1H MR spectroscopy were superimposed onto the corresponding MR images, the signal intensities of spectroscopically visible metabolites were analyzed in the regions in which the dipoles of the pathological activities were concentrated. Increased slow-wave activity was observed in four cases, and fast-wave or spike activity was significantly increased in one case each, respectively. These pathological activities were localized at almost the same cortical areas adjacent to the bulk of tumors, where mild reduction of N-acetyl aspartate (NAA) and slight accumulation of lactate consistently existed. Preserved and metabolically active cortical areas, which are indicated by residual NAA, might be able to generate pathological magnetic activities under lactic acidosis. Such an area could be understood as a border zone between normal brain tissue and brain tissue that has been seriously damaged by tumors or associated edema, which should be intensively treated. This combination of imaging techniques gives insight into functional as well as metabolic aspects of pathological brain conditions.
Dynamic and three-dimensional transcranial sonography studies of an asymptomatic, cerebral convexity arachnoid cyst
Authors: Schlachetzki Felix , Hölscher Thilo , Ullrich O.W. , Kübber M.D. Sabine , Blersch Wendelin , Götz Birgit , Ocklenburg Katrin , Schalke Berthold , Bogdahn Ulrich
Published: January 2008

Dynamic and three-dimensional transcranial sonography (dTCS and 3D-TCCS) examinations are complementary, noninvasive methods used in the assessment and follow up of patients with cerebrospinal fluid (CSF) circulation disorders.

A 16-year-old female patient who presented with a space-occupying, cerebral convexity arachnoid cyst and recurrent tension-type headache underwent examination for raised intracranial pressure (ICP) by using a standard color-coded duplex sonography system attached to a personal computer–based system for 3D data acquisition. Conventional TCS identified the outer arachnoid membrane of the cyst, which undulated freely after short rotation of the head (“headshake maneuver”). The undulation was documented as a QuickTime movie that is included with this article. A 3D dataset was acquired and, by using a multiplanar reformatting reconstruction algorithm, the authors obtained images with excellent resolution that corresponded to an initial magnetic resonance (MR) imaging study. No differences on dTCS and 3D-TCS were detectable at follow up 9 months later, indicating normal ICP and a stable, benign condition.

The use of 3D-TCCS and dTCS ultrasonography may complement other diagnostic procedures such as MR imaging and, thus, can improve management and therapeutic strategies for patients with CSF circulation disorders. In this report the authors present evidence of the excellent fine resolution and exact reproducibility of reconstructed ultrasound image planes derived from 3D datasets and the additional biomedical information from dynamic imaging.
Chronic Brain Inflammation and Persistent Herpes Simplex Virus 1 Thymidine Kinase Expression in Survivors of Syngeneic Glioma Treated by Adenovirus-Mediated Gene Therapy: Implications for Clinical Trials
Authors: Couldwell William T.
Published: January 2008

The long-term consequences of adenovirus-mediated conditional cytotoxic gene therapy for gliomas remain uncharacterized. We report here detection of active brain inflammation 3 months after successful inhibition of syngeneic glioma growth. The inflammatory infiltrate consisted of activated macrophages/microglia and astrocytes, and T lymphocytes positive for leucosyalin, CD3 and CD8, and included secondary demyelination. We detected strong widespread herpes simplex virus 1 thymidine kinase immunoreactivity and vector genomes throughout large areas of the brain. Thus, patient evaluation and the design of clinical trials in ongoing and future gene therapy for brain glioblastoma must address not only tumor-killing efficiency, but also long-term active brain inflammation, loss of myelin fibers and persistent transgene expression.
Tomita H, Ohbayashi M, Nakahara K, Hasegawa I, Miyashita Y
Authors: Couldwell William T.
Published: January 2008

Knowledge or experience is voluntarily recalled from memory by reactivation of the neural representations in the cerebral association cortex. In inferior temporal cortex, which serves as the storehouse of visual long-term memory, activation of mnemonic engrams through electric stimulation results in imagery recall in humans, and neurons can be dynamically activated by the necessity for memory recall in monkeys. Neuropsychological studies and previous split-brain experiments predicted that prefrontal cortex exerts executive control upon inferior temporal cortex in memory retrieval; however, no neuronal correlate of this process has ever been detected. Here we show evidence of the top-down signal from prefrontal cortex. In the absence of bottom-up visual inputs, single inferior temporal neurons were activated by the top-down signal, which conveyed information on semantic categorization imposed by visual stimulus-stimulus association. Behavioural performance was severely impaired with loss of the top-down signal. Control experiments confirmed that the signal was transmitted not through a subcortical but through a fronto-temporal cortical pathway. Thus, feedback projections from prefrontal cortex to the posterior association cortex appear to serve the executive control of voluntary recall.
Efficacy of variable-angle screws in transpedicular fixation
Authors: Arnold Paul M. , Strang Robert D. , Roussel Danielle
Published: January 2008

The purpose of this study was to evaluate the usefulness and efficacy of variable-angle screws in transpedicular fixation.

Sixteen patients (10 men and six women, age range 44–73 years) underwent a posterior transpedicular fixation procedure in which variable-angle screws were placed at two or more levels. Four patients experienced spinal instability secondary to trauma, 10 patients suffered from degenerative spondylosis requiring fusion, and two patients were treated for spinal metastatic disease. All patients underwent posterior transverse process fusion in which autologous bone was used. In total, 37 vertebral levels were fixed with variable-angle screws placed at 22 levels. Postoperatively all patients were fitted with an external orthosis that was worn for 12 weeks. Serial postoperative plain x-ray films were obtained in all cases. Follow-up periods ranged from 11 to 24 months.

Based on clinical and radiographic data, solid fusion was achieved in 14 of 16 patients. There were two early disconnections of the rod/screw connectors, which were related to errors in technique. With the exception of these disconnections, there were no cases of construct failure. There were no wound infections, and no patient experienced a decline in neurological function as compared with preoperative levels. Both instrumentation systems were easy to use, and the flexibility in trajectory allowed for quicker screw placement and decreased operating room time.

Variable-angle pedicle screws are a safe, useful adjunct to transpedicular fixation, particularly in multisegment fixation and in spines with abnormal alignment.
Analysis of pediatric head injury from falls
Authors: Kim K. Anthony , Wang Michael Y. , Griffith Pamela M. , Summers Susan , Levy Michael L.
Published: January 2008

The authors conducted a study to describe the incidence and types of fall-related head injury observed at a pediatric trauma center.

We performed a retrospective analysis of all patients under 15 years of age treated for fall-related trauma between 1992 and 1998. Falls were classified as low (< 15 feet) and high level (≥ 15 feet).

Seven hundred twenty-nine cases were identified with a mortality rate of 1.7%. A fall of greater than 15 feet (high-level fall) was associated with a higher mortality rate than low-level falls (2.4% compared with 1.0%, respectively). Ninety-eight patients had sustained a calvarial fracture and 93 experienced a basal skull fracture. Twenty-six patients had suffered a cerebral contusion, 25 a sub-arachnoid hemorrhage, 22 a subdural hematoma, and 12 had an epidural hematoma. Forty-nine patients required surgery for traumatic injuries; of these, 10 underwent craniotomy for evacuation of a blood clot. Height was not predictive of the Glasgow Coma Scale (GCS) score. In all four deaths resulting from a low-level fall there was an admission GCS score of 3, and abnormal findings were demonstrated on computerized tomography scanning. Death from high-level falls was attributable to either intracranial injuries (50%) or severe extracranial injuries (50%).

Intracranial injury is the major source of fall-related death in children and, unlike extracranial insults, brain injuries are sustained with equal frequency from low- and high-level falls in this population. The only cause of mortality from low-level falls was intracranial injury. Trauma triage criteria must account for these differences in the pediatric population.
Prognostic factors in the occurrence of posttraumatic epilepsy after penetrating head injury suffered during military service
Authors: Aarabi Bizhan , Taghipour Musa , Haghnegahdar Ali , Farokhi Majidreza , Mobley Lloyd
Published: January 2008

In this retrospective study, the authors evaluated confounding risk factors, which are allegedly influential in causing unprovoked posttraumatic epilepsy, in 489 patients from the frontlines of the Iran–Iraq War.

Four hundred eighty-nine patients were followed for 6 to154 months (mean 39.4 months, median 23 months), and important factors precipitating posttraumatic epilepsy were evaluated using uni- and multivariate regression analysis.

One hundred fifty-seven (32%) of 489 patients became epileptic during the study period. The results of univariate analysis indicated a significant relationship between epilepsy and Glasgow Outcome Scale (GOS) score (X2 = 76.49, p < 0.0001, df = 2), Glasgow Coma Scale score at admission (X2 = 19.48, p < 0.0001, df = 3), motor deficit (X2 = 11.79, p < 0.001, df = 1), mode of injury (X2 = 10.731, p < 0.05), transventricular injury (X2 = 6.9, p < 0.008, df = 1), dysphasia (X2 = 5.3, p < 0.02), central nervous system infections (X2 = 5.3, p < 0.02), and early-onset seizures (X2 = 4.1, p < 0.04, df = 1). The results of multivariate analysis, on the other hand, indicated that the GOS score and motor deficit were of greater statistical importance (X2 = 35.24, p < 0.0001; and X2 = 7.1, p < 0.07, respectively). Factors that did have much statistically significant bearing on posttraumatic epilepsy were the projectile type, site of injury on the skull, patient age, number of affected lobes, related hemorrhagic complications, and retained metallic or bone fragments.

Glasgow Outcome Scale score and focal motor neurological deficit are of particular importance in predicting posttraumatic epilepsy after missile head injury.