bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical outcomes of the Dynesys dynamic neutralization system: 1-year preliminary results
Authors: Welch William C. , Cheng Boyle C. , Awad Tariq E. , Davis Reginald , Maxwell James H. , Delamarter Rick , Wingate Jeffrey K. , Sherman John , Macenski M. Mason
Published: January 2008

Object

In this study the authors present the preliminary clinical outcomes of dynamic stabilization with the Dynesys spinal system as part of a multicenter randomized prospective Food and Drug Administration (FDA) investigational device exemption (IDE) clinical trial.

Methods

This study included 101 patients from six IDE sites (no participants were omitted from the analysis) who underwent dynamic stabilization of the lumbar spine with the Dynesys construct. Patient participation was based on the presence of degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis, and their physician's determination that the patient required decompression and instrumented fusion for one or two contiguous spinal levels between L-1 and S-1. Participants were evaluated preoperatively, postoperatively at 3 weeks, and then at 3-, 6-, and 12-month intervals. The 100-mm visual analog scale was used to score both lower-limb and back pain. Patient functioning was evaluated using the Oswestry Disability Index (ODI), and the participants' general health was assessed using the Short Form-12 questionnaire. Overall patient satisfaction was also reported.

One hundred one patients (53 women and 48 men) with a mean age of 56.3 years (range 27–79 years) were included. The mean pain and function scores improved significantly from the baseline to 12-month follow-up evaluation, as follows: leg pain improved from 80.3 to 25.5, back pain from 54 to 29.4, and ODI score from 55.6 to 26.3%.

Conclusions

The early clinical outcomes of treatment with Dynesys are promising, with lessening of pain and disability found at follow-up review. Dynesys may be preferable to fusion for surgical treatment of degenerative spondylolisthesis and stenosis because it decreases back and leg pain while avoiding the relatively greater tissue destruction and the morbidity of donor site problems encountered in fusion. However, long-term follow-up care is still recommended.
Multiple spinal extradural arachnoid cysts occurring in a child
Authors: Suryaningtyas Wihasto , Arifin Muhammad
Published: January 2008

✓Symptomatic multiple extradural arachnoid cysts of the spine are extremely uncommon in children and have only rarely been reported. The authors report a case of multiple extradural spinal arachnoid cysts in a 14-year-old child who presented with signs of spinal cord compression. The disease affected the thoracic spine and extended from T-5 to T-10 with an underlying defect in the dura of the spinal canal that was predisposed to the formation of cysts. The authors describe the imaging examination, surgical planning, and surgical technique, and they review the literature. They also discuss the possible mechanisms of cyst formation.
Placement of subdural electrode grids for seizure focus localization in patients with a large arachnoid cyst
Authors: Kushen Medina C. , Frim David
Published: January 2008

✓Subdural electrode arrays are placed to localize seizure foci for possible resection. The procedure is usually straightforward when an electrode grid array is placed on the brain convexity but can become complicated if the surface on which the grids are applied is not convex. Arachnoid cysts can be associated with seizures, but their topography presents a challenge to standard techniques for the placement of subdural grids. The authors report on a technique for electrode grid placement that successfully localized seizure foci in the depths of arachnoid cysts in two patients.

Subdural grids were placed to conform to the concave cyst cavity. They were held in place with rolled gelatin foam padding, which filled the arachnoid cyst. The padding was removed before removing the electrode grids and resecting the seizure focus.

Although arachnoid cysts present a technical challenge when seizure foci are located within the cyst cavity, the technique of packing the cyst cavity with gelatin foam provides good electrode contact on the concave cyst wall, allowing adequate seizure focus localization.
Medical management of cerebral edema
Authors: Raslan Ahmed , Bhardwaj Anish
Published: January 2008

✓Cerebral edema is frequently encountered in clinical practice in critically ill patients with acute brain injury from diverse origins and is a major cause of increased morbidity and death in this subset of patients. The consequences of cerebral edema can be lethal and include cerebral ischemia from compromised regional or global cerebral blood flow (CBF) and intracranial compartmental shifts due to intracranial pressure gradients that result in compression of vital brain structures. The overall goal of medical management of cerebral edema is to maintain regional and global CBF to meet the metabolic requirements of the brain and prevent secondary neuronal injury from cerebral ischemia. Medical management of cerebral edema involves using a systematic and algorithmic approach, from general measures (optimal head and neck positioning for facilitating intracranial venous outflow, avoidance of dehydration and systemic hypotension, and maintenance of normothermia) to specific therapeutic interventions (controlled hyperventilation, administration of corticosteroids and diuretics, osmotherapy, and pharmacological cerebral metabolic suppression). This article reviews and highlights the medical management of cerebral edema based on pathophysiological principles in acute brain injury.
A review of progress in understanding the pathophysiology and treatment of brain edema
Authors: Marmarou Anthony
Published: January 2008

Object

Brain edema resulting from traumatic brain injury (TBI) or ischemia if uncontrolled exhausts volume reserve and leads to raised intracranial pressure and brain herniation. The basic types of edema—vasogenic and cytotoxic—were classified 50 years ago, and their definitions remain intact.

Methods

In this paper the author provides a review of progress over the past several decades in understanding the pathophysiology of the edematous process and the success and failures of treatment. Recent progress focused on those manuscripts that were published within the past 5 years.

Results

Perhaps the most exciting new findings that speak to both the control of production and resolution of edema in both trauma and ischemia are the recent studies that have focused on the newly described “water channels” or aquaporins. Other important findings relate to the predominance of cellular edema in TBI.

Conclusions

Significant new findings have been made in understanding the pathophysiology of brain edema; however, less progress has been made in treatment. Aquaporin water channels offer hope for modulating and abating the devastating effects of fulminating brain edema in trauma and stroke.
The role of aquaporin-4 in cerebral water transport and edema
Authors: Bloch Orin , Manley Geoffrey T.
Published: January 2008

✓Despite decades of research into the pathogenesis of cerebral edema, nonsurgical therapy for brain swelling has advanced very little after more than half a century. Recent advancements in our understanding of molecular water transport have generated interest in new targets for edema therapy. Aquaporin-4 (AQP4) is the primary cellular water channel in the brain, localized to astrocytic foot processes along the blood–brain barrier and brain–cerebrospinal fluid interface. Multiple studies of transgenic mice with a complete deficiency or altered expression of AQP4 suggest a prominent role for AQP4 in cerebral water transport. In models of cellular (cytotoxic) edema, AQP4 deletion or alteration has been shown to be protective, reducing edema burden and improving overall survival. In contrast, AQP4 deletion in extra-cellular (vasogenic) edema results in decreased edema clearance and greater progression of disease. The data strongly support the conclusion that AQP4 plays a pivotal role in cerebral water transport and is an essential mediator in the formation and resorption of edema fluid from the brain parenchyma. These findings also suggest that drug therapy targeting AQP4 function and expression may dramatically alter our ability to treat cerebral edema.
Potential mechanisms and clinical significance of global cerebral edema following aneurysmal subarachnoid hemorrhage
Authors: Mocco J , Prickett Carlton S. , Komotar Ricardo J. , Connolly E. Sander , Mayer Stephan A.
Published: January 2008

✓In an attempt to elucidate the pathophysiology and clinical significance of global cerebral edema (GCE) following aneurysmal subarachnoid hemorrhage (SAH), the authors explored potential mechanisms and reviewed findings associated with this phenomenon. Admission computed tomography (CT) scans show GCE in up to 20% of patients experiencing aneurysmal SAH. This edema is likely to have been initiated by transient global ischemia, as indicated by an association between ictal loss of consciousness and the development of edema. A further cascade of events, including a rise in intracranial pressure and compromise of the blood–brain barrier, are also likely contributors. Clinically, GCE on CT after aneurysmal SAH is predictive of a poor outcome. Further investigation is needed to gain a full understanding of edema development following SAH, with the hope that the knowledge can be used to influence treatment positively and improve outcome.
Peroneal intraneural ganglia
Authors: Spinner Robert J. , Desy Nicholas M. , Rock Michael G. , Amrami Kimberly K.
Published: January 2008

✓The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.
A brief history of surgery for peripheral nerve sheath tumors
Authors: Powers Ciaran J. , Friedman Allan H.
Published: January 2008

✓The authors present a brief and selective history of surgery for peripheral nerve tumors to illustrate how the current understanding of the nature of disease influences the choice of surgical intervention. There was very little understanding of the anatomy and function of peripheral nerves in ancient times; consequently, surgical treatments for peripheral nerve tumors were based on the writings of authorities. The confusion between traumatic neuromas and genuine nerve sheath tumors coupled with the belief that manipulation of a peripheral nerve might be lethal to the patient stifled the development of surgical techniques for the management of nerve tumors in the 18th and 19th centuries. It was not until the 20th century, with an increased understanding of the microscopic anatomy of nerve sheath tumors, that efficacious surgical treatments for these diseases were developed. Continued advances in the understanding of the biology of these tumors will continue to impact their surgical management.
Schwannomatosis in a patient with a pelvic mass
Authors: Harbaugh Kimberly , Smith Patricia , Towfighi Javad
Published: January 2008

✓Schwannomatosis is the most recently recognized form of neurofibromatosis in which patients harbor multiple non–vestibular nerve schwannomas. The diagnosis is contingent on excluding neurofibromatosis Type 2 (NF2), to which it is related. The authors present a case of schwannomatosis diagnosed fortuitously when a preoperative magnetic resonance (MR) image of a pelvic schwannoma was suggestive of a lesion in the lower lumbar canal. Definitive studies confirmed the presence of multiple spinal tumors including a thoracic schwannoma, which was removed during a subsequent procedure. This case emphasizes the need to consider the possibility of multiple tumors in every patient presenting with a schwannoma because the follow-up and genetic counseling are vastly different in those with NF2 and schwannomatosis compared with those harboring sporadic tumors. Details of this case and current considerations in the diagnosis and management of schwannomatosis are discussed.
Medical management of Cushing disease
Authors: Gross Bradley A. , Mindea Stefan A. , Pick Anthony J. , Chandler James P. , Batjer H. Hunt
Published: January 2008

✓Although transsphenoidal excision of the adrenocorticotropic hormone (ACTH)–producing neoplasm is often the treatment of choice in patients with Cushing disease, medical management is itself a useful preoperative temporizing measure, an option for long-term management in nonsurgical candidates, and an option for patients in whom surgery and/or radiotherapy have failed. Three pathophysiologically based approaches exist in the research literature—neuro-modulation to limit ACTH levels, adrenal enzyme inhibition, and glucocorticoid receptor antagonism. Unfortunately, the neuromodulatory approach involving agents such as bromocriptine, cyproheptadine, octreotide, and valproate has yielded only suboptimal results. Glucocorticoid receptor antagonism remains in its infancy but may overall be limited by side effects and a resultant increase in ACTH and cortisol levels. Adrenal enzyme inhibitors, however, offer substantial future promise in the management of Cushing disease but are limited by the potential need to use them indefinitely and by dose-tolerance effects.

Although etomidate is a potential intravenous alternative for acute cortisol level control, ketoconazole has shown efficacy in the long-term treatment of patients with the disease. Metyrapone and/or aminoglutethimide can be added to ketoconazole if additional control is needed. If success is still not achieved, the potent adrenolytic agent often used for adrenocortical carcinomas, mitotane, is another alternative.
Nelson syndrome: historical perspectives and current concepts
Authors: Hornyak Mark , Weiss Martin H. , Nelson Don H. , Couldwell William T.
Published: January 2008

✓The appearance of an adrenocorticotropic hormone (ACTH)–producing tumor after bilateral adrenalectomy for Cushing disease was first described by Nelson in 1958. The syndrome that now bears his name was characterized by hyperpigmentation, a sellar mass, and increased plasma ACTH levels. The treatment of Cushing disease has changed drastically since the 1950s, when the choice was adrenalectomy. Thus, the occurrence, diagnosis, and treatment of Nelson syndrome have changed as well. In the modern era of high-resolution neuroimaging, transsphenoidal microneu-rosurgery, and stereotactic radiosurgery, Nelson syndrome has become a rare entity. The authors describe the history of the diagnosis and treatment of Nelson syndrome. In light of the changes described, the authors believe this disease must be reevaluated in the contemporary era and a modern paradigm adopted.
Evaluation and management of Cushing syndrome in cases of negative sellar magnetic resonance imaging
Authors: Jagannathan Jay , Sheehan Jason P. , Jane John A.
Published: January 2008

✓ The treatment of patients with Cushing disease and without magnetic resonance (MR) imaging evidence of Cushing disease (that is, negative MR imaging) is discussed in this paper. Magnetic resonance imaging is the diagnostic modality of choice in Cushing disease, but in up to 40% of these patients negative imaging can be caused by tumor-related factors and limitations in imaging techniques. In cases in which the MR imaging is negative, it is critical to make sure that the diagnosis of Cushing disease is correct. This can be accomplished by performing a complete laboratory and imaging workup, including dexamethasone suppression tests, imaging of the adrenal glands, and inferior petrosal sinus sampling when appropriate. If these evaluations suggest a pituitary source of the hypercortisolemia, then transsphenoidal surgery remains the treatment of choice. The authors favor the endoscopic approach because it gives a wider and more magnified view of the sella and allows inspection of the medial cavernous sinus walls. Radiosurgery is an effective treatment option in patients with persistent Cushing disease. When a target cannot be found on MR imaging, one can target the entire sellar region with radiosurgery.
Relation among aneurysm size, amount of subarachnoid blood, and clinical outcome
Authors: Salary Montell , Quigley Matthew R. , Wilberger Jack E.
Published: January 2008

Object

The authors of recent reports have suggested that smaller aneurysms are associated with more extensive sub-arachnoid hemorrhage (SAH), which could potentially presage poor outcome in patients harboring these lesions. The authors reviewed their clinical experience to determine if this theory has a basis in truth.

Methods

The authors undertook a retrospective review of a consecutive series of patients with aneurysmal SAH. Computed tomography scans and angiograms were studied to establish SAH scores and aneurysm size.

Results

One hundred thirty-three patients were treated during a 2-year period (January 2003–December 2004). There were 101 female and 32 male patients whose mean age was 56.7 years. The location distribution of aneurysms that bled was as follows: anterior communicating artery (56 cases), posterior communicating artery (34 cases), middle cerebral artery (21 cases), posterior circulation (16 cases), and paraclinoid region (six cases). The mean aneurysm size was 6.2 mm (range 2–26 mm). The mean SAH score was 18.3 (not normally distributed, p < 0.01, D'Agostino–Pearson test). One hundred three patients underwent surgical exploration and placement of an aneurysm clip, 21 underwent deployment of a coil, and two underwent both therapies; seven patients died prior to intervention.

No correlation was found between aneurysm size and SAH score (rS = −0.023, p = 0.8) or between small aneurysm size and poor Glasgow Outcome Scale score (p = 0.13). In fact, the trend was the opposite. The SAH score did, however, correspond strongly with the admission Hunt and Hess grade (p < 0.0001), indicating the strong correlation between grade and volume of intracranial blood. Outcome was best explained in the multivariate analysis by the following factors: admission Hunt and Hess grade, age, and clinical vasospasm (p < 0.0001) with the proportion of cases correctly classified as 79.7%.

Conclusions

Evaluation of the results in the present clinical series suggests that there is no relation between aneurysm size and volume of subarachnoid blood. The volume of cisternal blood correlates with Hunt and Hess grade but is not an independent determinant of outcome. Outcome is related to the following triad of well-established clinical factors: Hunt and Hess grade, age, and clinical vasospasm.
Subthalamic nucleus deep brain stimulation for severe idiopathic dystonia: impact on severity, neuropsychological status, and quality of life
Authors: Kleiner-Fisman Galit , Lin Liang Grace S. , Moberg Paul J. , Ruocco Anthony C. , Hurtig Howard I. , Baltuch Gordon H. , Jaggi Jurg L. , Stern Matthew B.
Published: January 2008

Object

Medically refractory dystonia has recently been treated using deep brain stimulation (DBS) targeting the globus pallidus internus (GPI). Outcomes have varied depending on the features of the dystonia. There has been limited literature regarding outcomes for refractory dystonia following DBS of the subthalamic nucleus (STN).

Methods

Four patients with medically refractory, predominantly cervical dystonia underwent STN DBS. Intraoperative assessments with the patients in a state of general anesthesia were performed to determine the extent of fixed deformities that might predict outcome. Patients were rated using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) preoperatively and 3 and 12 months following surgery by a rater blinded to the study. Mean changes and standard errors of the mean in scores were calculated for each subscore of the two scales. Scores were also analyzed using analysis of variance and probability values were generated. Neuropsychological assessments and quality of life ratings using the 36-Item Short Form Health Survey (SF-36) were evaluated longitudinally.

Results

Significant improvements were seen in motor (p = 0.04), disability (p = 0.02), and total TWSTRS scores (p = 0.03). Better outcomes were seen in those patients who did not have fixed deformities. There was marked improvement in the mental component score of the SF-36. Neuropsychological function was not definitively impacted as a result of the surgery.

Conclusions

Deep brain stimulation of the STN is a novel target for dystonia and may be an alternative to GPI DBS. Further studies need to be performed to confirm these conclusions and to determine optimal candidates and stimulation parameters.
Contralateral conjugate eye deviation during deep brain stimulation of the subthalamic nucleus
Authors: Shields Donald C. , Gorgulho Alessandra , Behnke Eric , Malkasian Dennis , Desalles Antonio A. F.
Published: January 2008

Object

Deep brain stimulation of the subthalamic nucleus (STN) in patients with Parkinson disease is often very effective for treatment of debilitating motor symptoms. Nevertheless, the small size of the STN and its proximity to axonal projections results in multiple side effects during high-frequency stimulation. Contralateral eye deviation is produced in a small percentage of patients, but the precise mechanism of this side effect is at present poorly understood.

Methods

Contralateral eye deviation was produced by high-frequency stimulation of 22 contact sites in nine patients undergoing deep brain stimulation of the STN. The precise locations of these contacts were calculated and compiled in order to locate the stimulated structure responsible for eye deviation.

Results

The mean x, y, and z coordinates associated with contralateral eye deviation were found to be 11.57, 2.03, and 3.83 mm lateral, posterior, and inferior to the anterior commissure–posterior commissure midpoint, respectively. The point described by these coordinates is located within the lateral anterosuperior border of the STN.

Conclusions

Given that stimulation of frontal eye field cortical regions produces similar contralateral conjugate eye deviation, these results are best explained by electrical current spread to nearby frontal eye field axons coursing lateral to the STN within the internal capsule. Thus, placement of the implanted electrode in a more medial, posterior, and inferior position may bring resolution of these symptoms by reducing the amount of current spread to internal capsule axons.
Effect of delayed cerebral vasospasm on cerebrovascular endothelin A receptor expression and function
Authors: Vatter Hartmut , Konczalla Juergen , Weidauer Stefan , Preibisch Christine , Zimmermann Michael , Raabe Andreas , Seifert Volker
Published: January 2008

Object

The key role in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) is increasingly assigned to endothelin (ET)-1. Constriction of the cerebrovasculature by ET-1 is mainly mediated by the ETA receptor but is putatively altered during the development of cerebral vasospasm. Therefore, the aim in the present study was to characterize these alterations, with the emphasis on the ETA receptor.

Methods

Cerebral vasospasm was induced using the rat double-hemorrhage model and proven by perfusion weighted magnetic resonance imaging. Rats were killed on Day 5 after SAH, and immunohistochemical staining for ETA receptors was performed. The isometric force of basilar artery ring segments with (E+, control group) and without (E−, SAH group) endothelial function was measured. Concentration effect curves (CECs) for ET-1 were constructed by cumulative application in the absence and presence of the selective ETA receptor antagonist clazosentan (10−8 or 10−7 M).

Results

The CEC for E+ segments was significantly shifted to the left after SAH by a factor of 3.7, whereas maximum contraction was unchanged. In E− segments, the CECs were not shifted during cerebral vasospasm but the maximum contraction was significantly enhanced. The inhibitory potency of clazosentan yielded a pA2 value of 8.6 ± 0.2. Immunohistochemical staining of the smooth-muscle layer showed no significant increase of ETA receptor expression, but positive staining occurred in the endothelial space after SAH.

Conclusions

The present data indicate an enhanced contractile effect of the smooth-muscle ETA receptors in cases of cerebral vasospasm. The inhibitory potency of clazosentan on this contraction is increased. Furthermore, some evidence for an ETA receptor and an endothelium-dependent vasoactive effect after SAH is provided.
Selective differentiation of central nervous system–derived stem cells in response to cues from specific regions of the developing brain
Authors: Vorasubin Bonnie , Weedin John , Saljooque Farid , Wilkes Nathan , U Hoi Sang
Published: January 2008

Object

Each region of the brain is distinguished by specific and distinct markers and functions. The authors hypothesized that each region possesses unique trophic properties that dictate and maintain its development. To test this hypothesis, they isolated central nervous system (CNS) stem cells from fetal rodents, and these rat CNS-derived stem cells (RSCs) were placed in coculture with primary cultures of the developing neonatal hippocampus and hypothalamus to determine whether region-specific primary cells would direct the differentiation of stem cells in a region-specific manner.

Methods

Primary cultures were first established from the neonatal (3–7 days postnatal) hippocampus and hypothalamus. Rodent CNS stem cells, which had been genetically engineered to express green fluorescent protein, were then placed in coculture with the primary CNS cells. The expression of region-specific markers in the RSCs was then evaluated after 2 weeks using immunocytochemistry. Data from previous studies have indicated that primary adult cells lack a differentiation-inducing capacity.

Results

When placed in coculture with primary CNS cells, RSCs began to express both neuronal (MAP2) and glial (glial fibrillary acidic protein) markers. Those that were placed in coculture with hippocampal cells expressed region-specific markers such as γ-aminobutyric acid, whereas those placed in coculture with hypothalamic cells expressed growth hormone–releasing hormone primarily in the hypothalamus.

Conclusions

Pluripotential RSCs were induced to express region-specific phenotypes on coculture with primary cells derived from the developing hippocampus and hypothalamus. The differentiation of RSCs into specific lineages on exposure to specific cell types is likely modulated through direct cell–cell contact. Secreted factors from the primary neural cells may also play a role in this induction. Such a differentiation influence is also likely age dependent.
Anatomy of the falcine venous plexus
Authors: Tubbs R. Shane , Loukas Marios , Louis Robert G. , Shoja Mohammadali M. , Acakpo-Satchivi Leslie , Blount Jeffrey P. , Salter E. George , Oakes W. Jerry , Wellons John C.
Published: January 2008

Object

The superior and inferior sagittal sinuses have been well studied. Interestingly, other venous structures within the falx cerebri have received scant attention in the medical literature. The present study was performed to elucidate the presence and anatomy of these midline structures.

Methods

The authors examined 27 adult latex- or ink-injected cadaveric specimens to observe the morphological features of the sinuses within the falx cerebri (excluding the inferior and superior sagittal sinuses).

Results

All specimens were found to have an extensive network of small tributaries within the falx cerebri that were primarily concentrated in its posterior one third. In this posterior segment, these structures were usually more pronounced in the inferior two thirds. The portion of the falx cerebri not containing significant falcine venous sinus was termed a “safe area.” These vascular channels ranged in size from 0.5 mm to 1.1 cm (mean 0.6 mm); 100% of these vessels communicated with the inferior sagittal sinus. Classification of the structures was then performed based on communication of the falcine venous sinus with the superior sagittal sinus. Type I falcine sinuses had no communication with the superior sagittal sinus, Type II falcine sinuses had limited communication with the superior sagittal sinus, and Type III falcine sinuses had significant communication with the superior sagittal sinus. Seventeen (63%) of 27 specimens communicated with the superior sagittal sinus (Types II and III). Further subdivision revealed 10 Type I, seven Type II, and 10 Type III falcine venous plexuses.

Conclusions

There are other venous sinuses in the falx cerebri in addition to the superior and inferior sagittal sinuses. Neurosurgical procedures that necessitate incising or puncturing the falx cerebri can be done more safely via a described safe area. Given that the majority of specimens in the authors' study were found to have a plexiform venous morphology within the falx cerebri, they propose that these channels be referred to as the falcine venous plexus and not sinus. The falcine venous plexus should be taken into consideration by the neurosurgeon.
Traumatic midbrain hematoma in a patient presenting with an isolated palsy of voluntary facial movements
Authors: Bouras Triantafyllos , Stranjalis George , Sakas Damianos E.
Published: January 2008

✓The authors report on the case of a young man with a mild head injury and an isolated palsy of voluntary facial movements, attributed to a midbrain traumatic hematoma. This exception to the generally accepted conjunction between brainstem contusion and poor prognosis pertains to a special entity of midbrain laceration due to hyperextension of the head, with minimal influence on the level of consciousness. The clinical presentation of this lesion with facial palsy sparing emotion-related movement has rarely been described and offers a clue for exploring the neuroanatomy of facial movement.
Neuromodulation of the cingulum for neuropathic pain after spinal cord injury
Authors: Spooner John , Yu Hong , Kao Chris , Sillay Karl , Konrad Peter
Published: January 2008

✓The authors present a case in which high-frequency electrical stimulation of the cingulum using standard deep brain stimulation (DBS) technology resulted in pain relief similar to that achieved with cingulotomy and superior to that achieved with periventricular gray matter (PVG) stimulation.

This patient had a complete spinal cord injury at the C-4 level and suffered from medically refractory neuropathic pain. He underwent placement of bilateral cingulum and unilateral PVG DBS electrodes and a 1-week blinded stimulation trial prior to permanent implantation of a pulse generator. During the stimulation trial, the patient's pain level was assessed using a visual analog scale, and pain medication usage was recorded. During this period the patient was blinded to stimulation parameters. Stimulation of the cingulum provided better pain control than PVG stimulation or medication alone.

The authors believe that cingulum stimulation can benefit patients with severe neuropathic pain that is refractory to other treatments. Advantages over cingulotomy include reversibility and the ability to adjust stimulation parameters for optimum efficacy.
Real-time image-guided direct convective perfusion of intrinsic brainstem lesions
Authors: Lonser Russell R. , Warren Katherine E. , Butman John A. , Quezado Zenaide , Robison R. Aaron , Walbridge Stuart , Schiffman Raphael , Merrill Marsha , Walker Marion L. , Park Deric M. , Croteau David , Brady Roscoe O. , Oldfield Edward H.
Published: January 2008

✓Recent preclinical studies have demonstrated that convection-enhanced delivery (CED) can be used to perfuse the brain and brainstem with therapeutic agents while simultaneously tracking their distribution using coinfusion of a surrogate magnetic resonance (MR) imaging tracer. The authors describe a technique for the successful clinical application of this drug delivery and monitoring paradigm to the brainstem. Two patients with progressive intrinsic brainstem lesions (one with Type 2 Gaucher disease and one with a diffuse pontine glioma) were treated with CED of putative therapeutic agents mixed with Gd–diethylenetriamene pentaacetic acid (DTPA). Both patients underwent frameless stereotactic placement of MR imaging–compatible outer guide–inner infusion cannulae. Using intraoperative MR imaging, accurate cannula placement was confirmed and real-time imaging during infusion clearly demonstrated progressive filling of the targeted region with the drug and Gd-DTPA infusate. Neither patient had clinical or imaging evidence of short- or long-term infusate-related toxicity. Using this technique, CED can be used to safely perfuse targeted regions of diseased brainstem with therapeutic agents. Coinfused imaging surrogate tracers can be used to monitor and control the distribution of therapeutic agents in vivo. Patients with a variety of intrinsic brainstem and other central nervous system disorders may benefit from a similar treatment paradigm.
Usefulness of 123I-iomazenil single-photon emission computed tomography in discriminating between mesial and lateral temporal lobe epilepsy in patients in whom magnetic resonance imaging demonstrates normal findings
Authors: Umeoka Shuichi , Matsuda Kazumi , Baba Koichi , Usui Naotaka , Tottori Takayasu , Terada Kiyohito , Usui Keiko , Nakamura Fumihiro , Inoue Yushi , Fujiwara Tateki , Mihara Tadahiro
Published: January 2008

Object

To provide greater accuracy in determining the epileptogenic zone during preoperative evaluation, the authors retrospectively examined 123I-iomazenil single-photon emission computed tomography (IMZ SPECT) studies obtained in patients with temporal lobe epilepsy (TLE) in whom there was no evidence of an abnormality on magnetic resonance (MR) images.

Methods

Twelve patients, seven with mesial TLE (MTLE) and five with lateral TLE (LTLE), satisfied the criteria for inclusion in the study. The IMZ SPECT findings in these patients were reviewed retrospectively, and a comparison was made between findings in patients with MTLE and those in patients with LTLE.

Results

The IMZ SPECT studies demonstrated decreased IMZ uptake in the ipsilateral mesial temporal region and the anterobasal temporal lobe in all patients who had MTLE on only one side. On the other hand, IMZ SPECT examinations revealed low IMZ uptake in the ipsilateral lateral temporal lobe in four of five patients with LTLE in whom abnormal findings were restricted to the lateral neocortex. In the remaining patient with LTLE, abnormally low IMZ uptake was found in both mesial and lateral temporal lobes, although pure LTLE was diagnosed by an invasive electroencephalographic evaluation; this patient's habitual seizures continued even after temporal lobectomy, although his mesial structures were spared.

Conclusions

The authors report characteristics of IMZ SPECT findings that differed between patients with MTLE and those with LTLE. The IMZ SPECT examinations proved useful for preoperative evaluation and, to a certain extent, for discrimination between MTLE and LTLE in cases in which MR imaging demonstrated normal findings. The results of this study suggest that IMZ SPECT findings may reflect localization of the epileptogenic zone.
Selection of the donor nerve for end-to-side neurorrhaphy
Authors: Papalia Igor , Cardaci Aurelio , d'Alcontres Francesco Stagno , Lee Jennifer M. , Tos Pierluigi , Geuna Stefano
Published: January 2008

Object

The authors of other studies have reported that the selection of an agonistic donor nerve is required for recovering voluntary motor control after end-to-side nerve repair. In this experimental investigation, the authors' goal was to verify this assumption by performing end-to-side neurorrhaphy of the rat median nerve on its antagonistic radial nerve.

Methods

The left median nerve in 10 adult female rats was repaired by end-to-side neurorrhaphy after epineuriotomy on the radial nerve at the middle of the brachium. The time course of median nerve functional recovery was then assessed using the grasping test until postoperative Week 30. Before removing the nerve, the surgical site was carefully explored to exclude contamination by the proximal nerve stump, and the functional anatomy of median and radial nerves was assessed by electrical stimulation. Repaired nerves were then processed for resin embedding, and semithin sections were obtained for nerve fiber histomorphometry by using the dissector method.

Results

Repaired median nerves were repopulated by nerve fibers regenerating from the radial donor nerve as previously shown. Moreover, voluntary motor control of the flexor muscles innervated by the median nerve was progressively recovered beginning in postoperative Week 10 and reaching 42% of normal by Week 30.

Conclusions

Contrary to previously reported data, recovery of voluntary motor function after end-to-side nerve repair can also be expected when an antagonistic nerve is used as a donor nerve.
Electrocorticography discharge patterns in patients with a cavernous hemangioma and pharmacoresistent epilepsy
Authors: Ferrier Cyrille H. , Aronica Eleonora , Leijten Frans S. S. , Spliet Wim G. M. , Boer Karin , Van Rijen Peter C. , Van Huffelen Alexander C.
Published: January 2008

Object

Neurodevelopmental lesions (NDLs) such as glioneuronal tumors and cortical dysplasia produce characteristic electrocorticography (ECoG) discharge patterns. Because cavernomas, another congenital abnormality, are also associated with pharmacoresistant epilepsy, the authors wondered whether they exhibit discharge patterns similar to those occurring in NDLs.

Methods

Intraoperative ECoG recordings from 19 patients with cavernomas and 54 with NDLs were reviewed for continuous spikes, bursts, or recruiting discharges and to determine whether these patterns were spatially coincident with the lesion. Relative densities of microglia and the intensity of Fe3+ staining in surgical samples were evaluated. Seizure outcome was assessed 1 year after surgery.

Results

The mean ages at seizure onset and surgery were higher in patients in the cavernoma group than in the NDL group (22.5 and 36.4 years compared with 10.0 and 25.2 years, respectively). Neocortical discharge patterns occurred equally in patients with either cavernomas (53%) or NDLs (41%). In the mesiotemporal area coincident bursts occurred more often in patients with cavernomas than patients with NDLs (55% compared with 10%, respectively). Coincident continuous spiking was associated with a longer duration of epilepsy in patients with cavernomas (23.5 years compared with 11.4 years for those without coincident continuous spiking) and with a lower age at seizure onset in those with NDLs (4.1 years compared with 11.8 years for those without coincident continuous spiking). In the cavernoma group the absence of coincident bursts was associated with high microglia density. There were no associations between the intensity of Fe3+ staining and discharge patterns, although the discharge patterns were associated with a worse outcome in patients with NDLs.

Conclusions

In patients with NDLs, continuous spiking patterns may be markers of a widespread epileptogenic zone due to an early insult to the developing brain; in patients with cavernomas, such patterns may indicate secondary epileptogenesis. Microglia may inhibit discharge patterns in patients with cavernomas.
Improved distribution of small molecules and viral vectors in the murine brain using a hollow fiber catheter
Authors: OH Seunguk , Odland Rick , Wilson Scott R. , Kroeger Kurt M. , Liu Chunyan , Lowenstein Pedro R. , Castro Maria G. , Hall Walter A. , Ohlfest John R.
Published: January 2008

Object

A hollow fiber catheter was developed to improve the distribution of drugs administered via direct infusion into the central nervous system (CNS). It is a porous catheter that significantly increases the surface area of brain tissue into which a drug is infused.

Methods

Dye was infused into the mouse brain through convection-enhanced delivery (CED) using a 28-gauge needle compared with a 3-mm-long hollow fiber catheter. To determine whether a hollow fiber catheter could increase the distribution of gene therapy vectors, a recombinant adenovirus expressing the firefly luciferase reporter was injected into the mouse striatum. Gene expression was monitored using in vivo bioluminescent imaging. To assess the distribution of gene transfer, an adenovirus expressing green fluorescent protein was injected into the striatum using a hollow fiber catheter or a needle.

Results

Hollow fiber catheter–mediated infusion increased the volume of brain tissue labeled with dye by 2.7 times relative to needle-mediated infusion. In vivo imaging revealed that catheter-mediated infusion of adenovirus resulted in gene expression that was 10 times greater than that mediated by a needle. The catheter appreciably increased the area of brain transduced with adenovirus relative to a needle, affecting a significant portion of the injected hemisphere.

Conclusions

The miniature hollow fiber catheter used in this study significantly increased the distribution of dye and adenoviral-mediated gene transfer in the mouse brain compared with the levels reached using a 28-gauge needle. Compared with standard single-port clinical catheters, the hollow fiber catheter has the advantage of millions of nanoscale pores to increase surface area and bulk flow in the CNS. Extending the scale of the hollow fiber catheter for the large mammalian brain shows promise in increasing the distribution and efficacy of gene therapy and drug therapy using CED.
Bioluminescence monitoring of intracranial glioblastoma xenograft: response to primary and salvage temozolomide therapy
Authors: Dinca Eduard B. , Sarkaria Jann N. , Schroeder Mark A. , Carlson Brett L. , Voicu Ramona , Gupta Nalin , Berger Mitchel S. , James C. David
Published: January 2008

Object

Bioluminescence imaging (BLI) offers a rapid and accurate means for longitudinal study of tumor cell growth and response to therapy in rodent models. Because this technology has only recently come into use in the field of small animal imaging, applications in this area have been limited. In the current study we have applied BLI to the analysis of clinically relevant issues involving use of the DNA methylating agent temozolomide (TMZ) in a mouse model.

Methods

An invasive glioblastoma multiforme xenograft was modified for BLI via transduction with a luciferase-encoding lentivirus. Supratentorial tumors were established in athymic nude mice that were subsequently assigned randomly to control and TMZ treatment groups, and the extent of intracranial tumor was monitored using BLI.

Results

In an experiment designed to compare the extent of antitumor effect between a single high-dose TMZ treatment and a protracted low-dose TMZ regimen, BLI revealed the protracted regimen as having superior antitumor effect, and this interpretation was consistent with results from a survival comparison between the two TMZ treatment groups. In a second experiment designed to assess the utility of BLI for testing therapies against recurrent glioblastoma multiforme, mice with intracranial tumors were retreated with TMZ at a time when BLI monitoring revealed tumor regrowth following initial TMZ treatment, and retreatment was successful in providing additional survival benefit.

Conclusion

The results of these experiments indicate that BLI monitoring can be used as a surrogate for predicting survival benefit from TMZ treatment, permits early determination of relative survival benefit associated with distinct TMZ therapeutic regimens, and offers a means of investigating secondary/salvage therapy efficacy following tumor regrowth from initial therapy.
Distal aneurysms of basilar perforating and circumferential arteries
Authors: Sanchez-Mejia Rene O. , Lawton Michael T.
Published: January 2008

✓Distal aneurysms of basilar perforating and circumferential arteries are exceedingly rare. The authors encountered one patient with a distal basilar perforating artery aneurysm and two with aneurysms arising from circumferential branches of the basilar artery (BA). The diagnostic features, microsurgical treatment, and outcomes in these three patients are described. The first patient, a 27-year-old man, presented with an angiogram-negative subarachnoid hemorrhage (SAH), and subsequent readmission for a new hemorrhage revealed a centrally thrombosed aneurysm arising from a basilar apex perforating artery. The second patient, a 68-year-old man, presented for follow-up evaluation 2 months after an angio-gram-negative SAH, and an aneurysm was identified on a circumferential artery originating from the BA trunk. The third patient, a 2-year-old boy, presented with blunt head trauma and a pseudoaneurysm arising from a basilar apex circumferential artery.

All three aneurysms were managed microsurgically with aneurysm trapping, via either an orbitozygomatic or an extended retrosigmoid approach. Occlusion of the distal perforating or circumferential artery was well tolerated in all cases, with no neurological sequelae resulting from surgery. Features common to all three aneurysms were dolichoectatic morphology, intraluminal thrombus, and SAH. These aneurysms may be difficult to diagnose given their small size and delayed filling on angiographic studies. Consequently, their presence in cases of angiogram-negative SAH may be underestimated. These aneurysms are not amenable to endovascular treatment, but excellent results can be obtained with microsurgical exposure and trapping.
Transmaxillary exploration of the intracranial portion of the maxillary nerve in malignant perineural disease
Authors: DeMonte Franco , Hanna Ehab
Published: January 2008

Object

Achieving microscopically tumor-free margins during resection of skull base malignancies has consistently been identified as a positive prognostic factor for patient survival. When malignancies extend perineurally into the major nerves traversing the skull base and entering the cavernous sinus, achieving tumor-free margins can be challenging and typically necessitates performing a craniotomy to access the lateral wall of the cavernous sinus. This report describes a novel technique used to access and resect malignancy extending perineurally into the intracranial portion of V2 via the maxillary sinus.

Methods

Seven patients with maxillary sinus tumors and perineural extensions along V2, who underwent resection of the primary tumor and transmaxillary intracranial exposure and dissection of the maxillary nerve to achieve maximal tumor resection, were analyzed. Prospectively collected data, including symptoms, clinical signs, diagnostic imaging data, pathological diagnosis, incidence and nature of complications, adjuvant therapies, and oncological outcomes, were retrospectively analyzed.

Results

All patients in this cohort had trigeminal nerve symptomatology as well as abnormal enhancement in the pterygopalatine fissure as noted on magnetic resonance imaging. The transmaxillary exploration of the maxillary nerve technique was used in all seven patients, resulting in gross-total resection of the tumors in every patient. At the last follow-up (mean 30 months, range 13–58 months, in four of seven patients for > 2 years), six patients were alive without evidence of local disease. One patient with squamous cell carcinoma died of progressive infratemporal fossa and regional neck disease 26 months after resection. No intracranial or cavernous sinus disease was present.

Conclusions

This technique extended the limits of resection without the need for a craniotomy and improved local tumor control in this patient cohort.