bluuebunny/crossref_metadata_2025 huggingface dataset:
The intriguing encounters of Pavlov and Cushing
Authors: Shahlaie Kiarash , Watson Joseph C. , Benson Daniel R.
Published: May 2009

✓ Ivan Petrovich Pavlov and Harvey William Cushing were two of the most prominent neuroscientists of the early 20th century. Their contributions helped advance the understanding of the brain and its disorders, and propelled neuroscience into a new era of research and treatment. Although separated geographically and culturally, Pavlov and Cushing exchanged letters and followed one another's careers from afar. They met only a few times, during international scientific gatherings in the US and abroad. These encounters were captured in journal entries, letters, and photographs, and provide a glimpse into the lives of these two great men and the history of neuroscience at the turn of the last century.
Microelectrode recording revealing a somatotopic body map in the subthalamic nucleus in humans with Parkinson disease
Authors: Romanelli Pantaleo , Heit Gary , Hill Bruce C. , Kraus Alli , Hastie Trevor , Brontë-Stewart Helen M.
Published: May 2009

Object. The subthalamic nucleus (STN) is a key structure for motor control through the basal ganglia. The aim of this study was to show that the STN in patients with Parkinson disease (PD) has a somatotopic organization similar to that in nonhuman primates.

Methods. A functional map of the STN was obtained using electrophysiological microrecording during placement of deep brain stimulation (DBS) electrodes in patients with PD. Magnetic resonance imaging was combined with ventriculography and intraoperative x-ray film to assess the position of the electrodes and the STN units, which were activated by limb movements to map the sensorimotor region of the STN. Each activated cell was located relative to the anterior commissure—posterior commissure line. Three-dimensional coordinates of the cells were analyzed statistically to determine whether those cells activated by movements of the arm and leg were segregated spatially.

Three hundred seventy-nine microelectrode tracks were created during placement of 71 DBS electrodes in 44 consecutive patients. Somatosensory driving was found in 288 tracks. The authors identified and localized 1213 movement-related cells and recorded responses from 29 orofacial cells, 480 arm-related cells, 558 leg-related cells, and 146 cells responsive to both arm and leg movements. Leg-related cells were localized in medial (p < 0.0001) and ventral (p < 0.0004) positions and tended to be situated anteriorly (p = 0.063) relative to arm-related cells.

Conclusions. Evidence of somatotopic organization in the STN in patients with PD supports the current theory of highly segregated loops integrating cortex—basal ganglia connections. These loops are preserved in chronic degenerative diseases such as PD, but may subserve a distorted body map. This finding also supports the relevance of microelectrode mapping in the optimal placement of DBS electrodes along the subthalamic homunculus.
A rapid noninvasive method to visualize ruptured aneurysms in the emergency room: three-dimensional power Doppler imaging
Authors: Perren Fabienne , Horn Peter , Kern Rolf , Bueltmann Eva , Hennerici Michael , Meairs Stephen
Published: May 2009

Object. Three-dimensional (3D) power Doppler ultrasonography imaging provides a rapid, noninvasive visualization of ruptured intracranial aneurysms, including their relationship to other vascular structures.

Methods. The authors used transcranial 3D power Doppler imaging in the emergency room to examine patients with acute subarachnoid hemorrhage. In all patients, the ruptured aneurysm was rapidly located with 3D power Doppler imaging. Conventional x-ray angiography confirmed both the ultrasonography-based diagnosis and the location of aneurysmal bleeding.

Conclusions. These preliminary results indicate that 3D power Doppler imaging is a rapid, noninvasive screening method for the visualization of ruptured aneurysms.
Progress in cerebral transplantation of expanded neuronal stem cells
Authors: Richardson R. Mark , Fillmore Helen L. , Holloway Kathryn L. , Broaddus William C.
Published: May 2009

Object. Given the success and limitations of human fetal primary neural tissue transplantation, neuronal stem cells (NSCs) that can be adequately expanded in culture have been the focus of numerous attempts to develop a superior source of replacement cells for restorative neurosurgery. To clarify recent progress toward this goal, the transplantation into the adult brain of NSCs, expanded in vitro before grafting, was reviewed.

Methods. Neuronal stem cells can be expanded from a variety of sources, including embryos, fetuses, adult bone marrow, and adult brain tissue. Recent investigations of each of these expanded stem cell types have generated a large body of information along with a great number of unanswered questions regarding the ability of these cells to replace damaged neurons. Expanded NSCs offer many advantages over their primary tissue predecessors, but also may exhibit different functional abilities as grafted cells. Because expanded NSCs will most likely ultimately replace primary tissue grafting in clinical trials, this review was undertaken to focus solely on this distinct body of work and to summarize clearly the existing preclinical data regarding the in vivo successes, limits, and unknowns of using each expanded NSC type when transplanted into the adult brain.

Conclusions. Embryonic stem cell—derived cells have demonstrated appropriate neuronal phenotypes after transplantation into nonneurogenic areas of the adult brain. Understanding the mechanisms responsible for this may lead to similar success with less studied adult neuronal progenitor cells, which offer the potential for autologous NSC transplantation with less risk of tumorigenesis.
Long-term stimulation of the subthalamic nucleus in hemiparkinsonian rats: neuroprotection of dopaminergic neurons
Authors: Maesawa Satoshi , Kaneoke Yoshiki , Kajita Yasukazu , Usui Naotaka , Misawa Nobuaki , Nakayama Atsuo , Yoshida Jun
Published: May 2009

Object. The goal of this study was to evaluate the neuroprotective effects conferred by long-term electrical stimulation of the subthalamic nucleus (STN) against degeneration of dopaminergic neurons by assessing motor functional and immunohistological findings in hemiparkinsonian rats.

Methods. In 13 of 25 rats, a concentric microelectrode was stereotactically implanted into the right STN under the guidance of extracellular microelectrode recording. After this had been done the animals were given an injection of 6-hydroxydopamine (6-OHDA) into the right striatum. Seven of the rats received continuous stimulation (frequency 130 Hz, intensity 80–100 µA) for 2 weeks (Group A); the other six did not receive any stimulation during this period (Group B). Twelve rats did not receive electrode implantation and underwent 6-OHDA injection only; these animals served as a control group (Group C). After 2 weeks, motor function in the rats was evaluated by conducting an amphetamine-induced rotation test. Finally, tyrosine hydroxylase—immunoreactive neurons in the pars compacta of the substantia nigra (SNc) were counted to evaluate the extent of degeneration of dopaminergic neurons. Ipsilateral rotation was significantly decreased in Group A, regardless of the effects of stimulation delivered during the test (p < 0.05). Rats in Group B demonstrated typical circling as did those in Group C, except that on stimulation Group B rats immediately stopped circling or changed direction. Tyrosine hydroxylase—immunoreactive neurons in the SNc were significantly preserved in the animals in Group A, whereas neurons in animals in Groups B and C were moderately depleted (p < 0.01).

Conclusions. Acutely, STN stimulation improved rotation symmetry in rats with moderate SNc degeneration. When STN stimulation had been applied for the preceding 2 weeks, motor function was better and SNc neural degeneration was significantly milder. Subthalamic nucleus stimulation thus appears to protect dopaminergic neurons in this hemiparkinsonian model, in addition to improving motor function in these animals.
Pallidal deep brain stimulation for longstanding severe generalized dystonia in Hallervorden—Spatz syndrome
Authors: Umemura Atsushi , Jaggi Jurg L. , Dolinskas Carol A. , Stern Matthew B. , Baltuch Gordon H.
Published: May 2009

✓ Generalized dystonia is one of the most disabling movement disorders. Ablative stereotactic surgery such as pallidotomy has been performed for medically refractory dystonia. Recently, deep brain stimulation (DBS) has appeared as an alternative to ablative procedures. Nevertheless, there have been few published reports detailing improvement in dystonia with DBS.

This 36-year-old man with Hallervorden—Spatz syndrome suffered from intractable primary generalized dystonia for 28 years. He was completely dependent for activities of daily living and wheelchair bound because of continuous severe dystonic movements in the face, tongue, neck, trunk, and upper and lower extremities while at rest. The Burke-Fahn-Marsden (BFM) Dystonia Rating Scale score was 112 (maximum 120 points). Bilateral DBS of the globus pallidus internus was performed and resulted in marked improvement in motor functioning and dystonic symptoms with a significant reduction in disability. The BFM score improved to 22.5 points (80% improvement) at 3 months postsurgery and the patient's dystonia was still well suppressed 1 year after surgery.

Bilateral pallidal stimulation is an effective and safe treatment for intractable generalized dystonia in Hallervorden—Spatz syndrome, even if the disability is severe and longstanding.
Abnormal coagulation studies associated with levoflaxacin
Authors: Psarros Thomas , Trammell Talmadge , Morrill Kevin , Giller Cole , Morgan Howard , Allen Beth
Published: May 2009

✓ Complications arising from antibiotic use are of interest to neurosurgeons because many neurosurgical patients are treated for infection. In this report, the authors describe three patients with spine disorders who developed coagulopathies after treatment with levofloxacin, an antibiotic commonly used by neurosurgical services.

Three patients with spine disorders developed urinary tract infections (UTIs) for which they received a 3-day course of oral levofloxacin. Subsequently, they demonstrated prolonged prothrombin times and increased international normalized ratios. One of those patients later developed acquired von Willebrand syndrome during surgery.

Coagulopathies were successfully corrected preoperatively with parenteral vitamin K. The patient with acquired von Willebrand syndrome required multiple transfusions.

There seems to be an association between levofloxacin and coagulation abnormalities in neurosurgical patients treated for UTIs. Neurosurgical services prescribing this common antibiotic should be aware of this problem.
Balloon-assisted microvascular clipping of paraclinoid aneurysms
Authors: Thorell William , Rasmussen Peter , Perl John , Masaryk Thomas , Mayberg Marc
Published: May 2009

✓ Paraclinoid aneurysms represent a significant surgical challenge. Multiple techniques have been developed to maximize the effectiveness and safety of excluding these aneurysms from the cerebral circulation. Endovascular balloons have been used for proximal control of parent arteries during the treatment of aneurysms. In this report the authors describe the technique of navigating an endovascular balloon across the neck of paraclinoid aneurysms in four patients to gain proximal control, improve the accuracy of clip placement, and reduce the risk of distal embolization of intraluminal thrombus.

Six consecutive patients with giant or complex aneurysms of the ophthalmic or paraclinoid internal carotid artery that were not amenable to endovascular obliteration were retrospectively analyzed. In all six patients, the aneurysm was exposed and dissected for microsurgical clipping, and attempts were made to navigate a nondetachable, compliant silicone balloon across the neck of the aneurysm. If successfully placed, the balloon was inflated during clip placement. In four patients, the balloon was successfully navigated across the neck of the aneurysm and was inflated during clip application. Internal carotid artery tortuosity precluded navigation of the balloon into the intracranial circulation in two patients. All aneurysms were completely excluded from the parent vessel according to postoperative angiography studies. No complication occurred as a direct result of the endovascular portion of the procedure.

Endovascular balloon stenting of complex paraclinoid aneurysms during microvascular clipping may provide an adjunctive therapy that facilitates safe and accurate clip placement.
Development of a cancer-specific anterior skull base quality-of-life questionnaire
Authors: Gil Ziv , Abergel Avraham , Spektor Sergey , Shabtai Esther , Khafif Avi , Fliss Dan M.
Published: May 2009

Object. The goal of this study was to develop a disease-specific, multidimensional quality of life (QOL) assessment instrument for patients undergoing surgical extirpation of anterior skull base tumors.

Methods. This investigation included 35 patients who had been surgically treated for more than 3 months before the study was begun. Relevant QOL questions were generated from a review of the literature and interviews with health professionals, patients, and their caregivers. The initial multidimensional, 80-item questionnaire was reduced to a 35-item questionnaire by using standard psychometric criteria. Six relevant domains were identified using factor analysis: performance, physical function, vitality, pain, specific symptoms, and influence on emotions. The internal consistency of the instrument had a correlation coefficient of 0.8 and a reliability coefficient (test—retest reliability) of 0.9. The validity of the construct was assessed by testing whether the clinical variable of the patient influenced his QOL domain score as hypothesized. Patients older than 60 years of age had significantly poorer scores in the domains of performance and physical function than younger patients. Patients with malignant tumors had significantly poorer scores in the domains of specific symptoms, influence on emotions, physical function, and performance compared with patients with benign tumors. Radiotherapy was associated with poorer scores in the domains of specific symptoms and influence on emotions. Comorbidity was associated with poor physical function scores. Using the final questionnaire, we prospectively evaluated the QOL of 12 additional patients before they underwent surgery and again between 5 and 6 months postoperatively to test the utility and validity of the instrument further. Again, significantly poorer QOL scores were recorded for patients with malignancy.

Conclusions. The proposed questionnaire appears to be sufficiently reliable and valid in estimating a patient's QOL after extirpation of anterior skull base tumors. The instrument can be used in face-to-face interviews and via electronic or regular mail.
Reliability of clinical guidelines in the detection of patients at risk following mild head injury: results of a prospective study
Authors: Ibañez Javier , Arikan Fuat , Pedraza Salvador , Sánchez Esther , Poca Maria A. , Rodriguez David , Rubio Enrique
Published: May 2009

Object. The aims of this study were to analyze the relevance of risk factors in mild head injury (MHI) by studying the possibility of establishing prediction models based on these factors and to evaluate the reliability of the clinical guidelines proposed for the management of MHI.

Methods. A series of 1101 patients with MHI were prospectively enrolled in this study. In all cases clinical data were collected and a computerized tomography (CT) scan was obtained. The relationship between clinical findings and the presence of intracranial lesions was studied to establish prediction models based on logistic regression and recursive partitioning analysis. Recently proposed guidelines and recommendations for the treatment of MHI were selected, calculating their diagnostic efficiency when applying each of them to our series.

The incidence of acute intracranial lesions was 7.5% (83 patients). A Glasgow Coma Scale score of 14, loss of consciousness, vomiting, headache, signs of basilar skull fracture, neurological deficit, coagulopathies, hydrocephalus treated with shunt insertion, associated extracranial lesions, and patient age greater than 65 years were identified as independent risk factors. Prediction models built on clinical variables were able to indicate patients with clinically important lesions, but failed to achieve 100% sensitivity in the detection of all patients with CT scans positive for intracranial lesions within reasonable specificity limits.

Conclusions. Clinical variables are insufficient to predict all cases of intracranial lesions following MHI, although they can be used to detect patients with relevant injuries. Avoiding systematic CT scan indication implies a rate of misdiagnosis that should be known and assumed when planning treatment in these patients by using guidelines based on clinical parameters.
Involuntary movement induced by cerebral ischemia: pathogenesis and surgical outcome
Authors: Im So-Hyang , Oh Chang Wan , Kwon O-Ki , Cho Byung-Kyu , Chung Young-Seob , Han Dae Hee
Published: May 2009

Object. Involuntary movement is an uncommon manifestation of a transient ischemic attack. It may be induced by cerebral hemodynamic insufficiency, which is associated with several cerebral ischemic diseases. The authors present three cases of limb shaking due to moyamoya disease (MMD) or radiation-induced middle cerebral artery stenosis, and three additional cases of choreic movement due to MMD. Neuroimaging studies and surgical outcomes in these patients were retrospectively analyzed to investigate the pathological mechanism underlying the symptoms and to provide guidance for the management of involuntary movement disorders in cases of ischemic cerebral disease.

Methods. The patient population included two children and four adults with ages at presentation ranging between 7 and 50 years. The initial presenting symptoms were involuntary movements in all six cases. A magnetic resonance imaging finding common in all cases was a small infarct in the frontal corona radiata, which did not extend to the cortex or basal ganglia. A perfusion defect in the frontoparietal cortical and subcortical regions was demonstrated by singlephoton emission computerized tomography in all patients. Improved hemodynamic circulation in the frontoparietal cortical and subcortical regions occurred in parallel with clinical improvement following indirect or direct bypass surgery.

Conclusions. Ischemic dysfunction of the frontal cortical and subcortical motor pathways rather than that of the basal ganglia was suspected to be the cause of the observed contralateral involuntary movements. Direct and indirect bypass surgery can be used effectively to treat involuntary movements in patients with cerebral ischemic diseases such as MMD and in those with stenosis of an intracranial major artery.
Neurosurgical implications of allergic fungal sinusitis
Authors: Liu James K. , Schaefer Steven D. , Moscatello Augustine L. , Couldwell William T.
Published: May 2009

Object. Allergic fungal sinusitis (AFS) is a form of paranasal mycosis that often involves bone destruction and extension into the orbit and anterior skull base. Treatment consists of surgical extirpation and a course of corticosteroids. Despite frequent intracranial involvement, AFS is rarely reported in the neurosurgical literature.

Methods. The records of 21 patients with the histological diagnosis of AFS were reviewed. The histological diagnosis was based on findings of branching septated fungi interspersed with eosinophilic mucin and Charcot—Leyden crystals without fungal invasion of soft tissue.

The average age of the 21 patients in this study was 25 years (range 9–46) and the male/female ratio was 3.75:1. All patients were immunocompetent. All had a history of chronic sinusitis and imaging findings of expansile disease involving multiple sinuses. Fifteen patients had nasal polyposis, eight had erosion of bone, which was observed on computerized tomography (CT) scans, eight had disease extending intracranially, and six had disease that involved the lamina papyracea. All patients underwent transnasal and/or transmaxillary endoscopic approaches for debridement and irrigation, six underwent orbital decompression, and three underwent a bifrontal craniotomy for removal of intracranial extradural disease. No patient had a cerebrospinal fluid leak. Postoperatively, one patient was treated with amphotericin B and the other 20 were treated with a short course of corticosteroids. The follow-up period ranged from 2 to 19 years.

Conclusions. Allergic fungal sinusitis is a unique form of fungal disease that may mimic anterior skull base and paranasal sinus tumors. A cranial base team approach of neurosurgeons and otolaryngologists is recommended. Most cases can be successfully managed with transnasal and/or transmaxillary endoscopic techniques. A craniotomy is rarely indicated unless there is the suspicion of dural invasion or extensive intracranial and/or intraorbital involvement that is inaccessible from below.
Microsurgical anatomy of the insula and the sylvian fissure
Authors: Tanriover Necmettin , Rhoton Albert L. , Kawashima Masatou , Ulm Arthur J. , Yasuda Alexandre
Published: May 2009

Object. The purpose of this study was to define the topographic anatomy, arterial supply, and venous drainage of the insula and sylvian fissure.

Methods. The neural, arterial, and venous anatomy of the insula and sylvian fissure were examined in 43 cerebral hemispheres.

Conclusions. The majority of gyri and sulci of the frontoparietal and temporal opercula had a constant relationship to the insular gyri and sulci and provided landmarks for approaching different parts of the insula. The most lateral lenticulostriate artery, an important landmark in insular surgery, arose 14.6 mm from the apex of the insula and penetrated the anterior perforated substance 15.3 mm medial to the limen insulae. The superior trunk of the middle cerebral artery (MCA) and its branches supplied the anterior, middle, and posterior short gyri; the anterior limiting sulcus; the short sulci; and the insular apex. The inferior trunk supplied the posterior long gyrus, inferior limiting sulcus, and limen area in most hemispheres. Both of these trunks frequently contributed to the supply of the central insular sulcus and the anterior long gyrus. The areas of insular supply of the superior and inferior trunks did not overlap. The most constant insular area of supply by the cortical MCA branches was from the prefrontal and precentral arteries that supplied the anterior and middle short gyri, respectively. The largest insular perforating arteries usually arose from the central and angular arteries and most commonly entered the posterior half of the central insular sulcus and posterior long gyrus. Insular veins drained predominantly to the deep middle cerebral vein, although frequent connections to the superficial venous system were found. Of all the insular veins, the precentral insular vein was the one that most commonly connected to the superficial sylvian vein.
Progressive neurological decline after partial spontaneous thrombosis of a Spetzler—Martin Grade 5 arteriovenous malformation in a patient with Leiden factor V mutation: management and outcome
Authors: Link Michael J. , Schermerhorn Thomas C. , Fulgham Jimmy R. , Nichols Douglas A.
Published: May 2009

✓ The coexistence of a large intracranial arteriovenous malformation (AVM) and a hypercoagulation disorder is rare. The AVM puts the patient at risk for progressive neurological deficit, seizures, and, most importantly, intracranial hemorrhage. The hypercoagulation disorder may result in an increased risk of stroke. The authors describe a 42-year-old man with a Spetzler—Martin Grade 5 AVM who experienced progressive neurological decline. He was subsequently discovered to have partial thrombosis of the AVM, deep cerebral and cortical venous thrombosis, and a hypercoagulation disorder. Hypercoagulation disorders causing neurological deficits are usually treated with anticoagulant medications; however, this approach was not thought to be safe in the presence of a large AVM. Therefore, the AVM nidus was surgically extirpated and a ventriculoperitoneal shunt was placed to treat the increased intracranial pressure caused by the cortical and deep cerebral venous thrombosis. Subsequently, lifelong oral anticoagulation was prescribed. The patient had a progressive neurological recovery and is now living independently at home. The occurrence of partial or complete spontaneous thrombosis of an AVM nidus should raise the possibility of an underlying hypercoagulation disorder.
Association between an aplastic basilar artery, unaccompanied by a primitive carotid—vertebrobasilar anastomosis, and multiple aneurysms on the dominant posterior communicating artery
Authors: Behari Sanjay , Krishna Himanshu , Kiran Kumar Marakani V. , Sawlani Vijay , Phadke Rajendra V. , Jain Vijendra K.
Published: May 2009

✓ Basilar artery (BA) aplasia when unaccompanied by a primitive carotid—vertebrobasilar anastomosis is exceedingly rare. The association of BA aplasia with two aneurysms on the dominant posterior communicating artery (PCoA) has not been previously reported.

This 40-year-old man presented in a state of drowsiness and responded to simple commands only after being coaxed. He had complete left cranial third nerve palsy, right hemiparesis, and persisting signs of meningeal irritation. A computerized tomography (CT) scan revealed subarachnoid and intraventricular hemorrhage. An angiogram revealed BA aplasia. The right PCoA followed a sinuous course with multiple loops and provided the dominant supply to the posterior circulation. This vessel harbored two aneurysms, one at the origin of the PCoA from the internal carotid artery and the other at the looping segment just proximal to the brainstem. The left PCoA was extremely thin. The pterional transsylvian approach was used to clip the two aneurysms on the PCoA.

The hemodynamic changes produced by the BA aplasia may have produced alterations in the cerebral vasculature leading to aneurysm formation and consequent subarachnoid hemorrhage.
Monitoring and preventing blood flow insufficiency due to clip rotation after the treatment of internal carotid artery aneurysms
Authors: Sakuma Jun , Suzuki Kyouichi , Sasaki Tatsuya , Matsumoto Masato , Oinuma Masahiro , Kawakami Masahisa , Itakura Takeshi , Kodama Namio
Published: May 2009

✓ The authors report a case in which anterior choroidal artery (AChA) blood flow insufficiency due to aneurysm clip rotation was detected intraoperatively by motor evoked potential (MEP) monitoring and ischemia was successfully avoided.

The patient had an incidentally discovered aneurysm for which occlusion of its neck was performed through a standard frontotemporal craniotomy without changing the MEP amplitude. After it was confirmed that the surrounding arteries were not stenotic, the brain retractor on the frontal lobe was released; MEP amplitude subsequently decreased. Rotation of the clip toward the frontal base by repositioning of the frontal lobe caused the AChA stenosis at the origin of its branches. On reorienting the clip toward the frontal lobe, the AChA stenosis was released and MEP amplitude recovered. To prevent repeated clip rotation, a large amount of gelatin (Spongel) was inserted between the frontal base and the clip. The authors confirmed that clip rotation did not occur after repositioning of the frontal lobe. Motor evoked potential amplitude was maintained until dural closure. Postoperatively, the patient demonstrated no neurological deficit and there was no newly developed low-density area on computerized tomography scans.
W. James Gardner: pioneer neurosurgeon and inventor
Authors: Nathoo Narendra , Mayberg Marc R. , Barnett Gene H.
Published: May 2009

✓ W. James Gardner, a skillful neurosurgeon and inventor, is best remembered for his cervical tongs and hydrodynamic theory of syringomyelia.

A pioneer of modern neurosurgery, Gardner trained under Charles Frazier in Philadelphia, and in 1929 he moved to Ohio where he became chief of neurosurgery at the Cleveland Clinic, a position he was to hold for the next 33 years. A large surgical practice made it imperative for Gardner to develop surgical methods that were quick, effective, and advantageous for patient and surgeon. He was an early proponent of the sitting position for patients undergoing cranial surgery, which led to the development of a neurosurgical chair with a head fixation device. To reduce the risks of hypotension and air embolism when the patient is in the sitting position, Gardner invented the clinical G suit. He was the first to advocate and use induced arterial hypotension for intracranial surgery and the first neurosurgeon in the US to publish his experiences performing lumbar discography. He converted an operating table so that he could induce hypothermia during aneurysm surgery and then applied pneumatic cuffs to occlude the major arterial supply to the brain. His pioneering work has been documented in many other areas such as hemifacial spasm and trigeminal neuralgia, for which he performed the first vascular decompression, in cervical sympathectomy for treatment of various ailments, and in the use of intrathecally delivered steroid drugs for sciatica. During his career, he authored 256 publications and one book on the dysraphic states. Many of his contributions to the discipline of neurosurgery are now taken for granted.
The mechanism and effect of chronic electrical stimulation of the globus pallidus for treatment of Parkinson disease
Authors: Ogura Mitsuhiro , Nakao Naoyuki , Nakai Ekini , Uematsu Yuji , Itakura Toru
Published: May 2009

Object. Although chronic electrical stimulation of the globus pallidus (GP) has been shown to ameliorate motor disabilities in Parkinson disease (PD), the underlying mechanism remains to be clarified. In this study the authors explored the mechanism for the effects of deep brain stimulation of the GP by investigating the changes in neurotransmitter levels in the cerebrospinal fluid (CSF) during the stimulation.

Methods. Thirty patients received chronic electrical stimulation of the GP internus (GPi). Clinical effects were assessed using the Unified PD Rating Scale (UPDRS) and the Hoehn and Yahr Staging Scale at 1 week before surgery and at 6 and 12 months after surgery. One day after surgery, CSF samples were collected through a ventricular tube before and 1 hour after GPi stimulation. The concentration of neurotransmitters such as γ-aminobutyric acid (GABA), noradrenaline, dopamine, and homovanillic acid (HVA) in the CSF was measured using high-performance liquid chromatography.

The treatment was effective for tremors, rigidity, and drug-induced dyskinesia. The concentration of GABA in the CSF increased significantly during stimulation, although there were no significant changes in the level of noradrenaline, dopamine, and HVA. A comparison between an increased rate of GABA concentration and a lower UPDRS score 6 months postimplantation revealed that the increase in the GABA level correlated with the stimulation-induced clinical effects.

Conclusions. Stimulation of the GPi substantially benefits patients with PD. The underlying mechanism of the treatment may involve activation of GABAergic afferents in the GP.
Three-dimensional visualization of neurovascular relationships in the posterior fossa: technique and clinical application
Authors: Naraghi Ramin , Hastreiter Peter , Tomandl Bernd , Bonk Agatha , Huk Walter , Fahlbusch Rudolf
Published: May 2009

Object. The goal of this study was to describe the authors' technique for three-dimensional (3D) visualization of neurovascular relationships in the posterior fossa at the surface of the brainstem. This technique is based on the processing of high-resolution magnetic resonance (MR) imaging data. The principles and technical details involved in the accurate simultaneous visualization of vessels and cranial nerves as tiny structures are presented using explicit and implicit segmentation as well as volume rendering.

Methods. In this approach 3D MR constructive interference in steady state imaging data served as the source for image processing, which was performed using the Linux-based software tools SegMed for segmentation and Qvis for volume rendering. A sequence of filtering operations (including noise reduction and closing) and other software tools such as volume growing are used for a semiautomatic coarse segmentation. The subsequent 3D visualization in which implicit segmentation is used for the differentiation of cranial nerves, vessels, and brainstem is achieved by allocating opacity and color values and adjusting the related transfer functions. This method was applied to the presurgical evaluation in a consecutive series of 55 patients with neurovascular compression syndromes and the results were correlated to surgical findings. The potential for its use, further developments, and remaining problems are discussed.

Conclusions. This method provides an excellent intraoperative real-time virtual view of difficult anatomical relationships.
Recombinant vesicular stomatitis virus vectors as oncolytic agents in the treatment of high-grade gliomas in an organotypic brain tissue slice—glioma coculture model
Authors: Duntsch Christopher D. , Zhou Qihong , Jayakar Himangi R. , Weimar James D. , Robertson Jon H. , Pfeffer Lawrence M. , Wang Lie , Xiang Zixiu , Whitt Michael A.
Published: May 2009

Object. The purpose of this study was to evaluate both replication-competent and replication-restricted recombinant vesicular stomatitis virus (VSV) vectors as therapeutic agents for high-grade gliomas by using an organotypic brain tissue slice—glioma coculture system.

Methods. The coculture system involved growing different brain structures together to allow neurons from these tissues to develop synaptic connections similar to those found in vivo. Rat C6 or human U87 glioma cells were then introduced into the culture to evaluate VSV as an oncolytic therapy. The authors found that recombinant wild-type VSV (rVSV-wt) rapidly eliminated C6 glioma cells from the coculture, but also caused significant damage to neurons, as measured by a loss of microtubule-associated protein 2 immunoreactivity and a failure in electrophysiological responses from neurons in the tissue slice. Nonetheless, pretreatment with interferon beta (IFNβ) virtually eliminated VSV infection in healthy tissues without impeding any oncolytic effects on tumor cells. Despite the protective effects of the IFNβ pretreatment, the tissue slices still showed signs of cytopathology when exposed to rVSV-wt. In contrast, pretreatment with IFNβ and inoculation with a replication-restricted vector with its glycoprotein gene deleted (rVSV-ΔG) effectively destroyed rat C6 and human U87 glioma cells in the coculture, without causing detectable damage to the neuronal integrity and electrophysiological properties of the healthy tissue in the culture.

Conclusions. Data in this study provide in vitro proof-of-principle that rVSV-ΔG is an effective oncolytic agent that has minimal toxic side effects to neurons compared with rVSV-wt and therefore should be considered for development as an adjuvant to surgery in the treatment of glioma.
Involvement of epidermal growth factor receptor—protein tyrosine kinase transactivation in endothelin-1—induced vascular contraction
Authors: Kawanabe Yoshifumi , Masaki Tomoh , Hashimoto Nobuo
Published: May 2009

Object.Endothelin-1 (ET-1) is one of the major inducers of vasospasm following subarachnoid hemorrhage (SAH). It is generally accepted that extracellular signal—regulated kinase 1 and 2 (ERK1/2) are involved in ET-1—induced vascular contraction. In addition, ET-1 transactivates epidermal growth factor receptor (EGFR) protein tyrosine kinase (PTK), which leads to ERK1/2 stimulation. Therefore, the authors examined whether EGFR—PTK transactivation contributes to ET-1—induced vascular contraction in this study.

Methods.Mitogen-activated protein kinase inhibitor, PD98059, inhibited ET-1—induced ERK1/2 stimulation in rabbit basilar artery (BA) vascular smooth-muscle cells (VSMCs). Moreover, PD98059 inhibited ET-1—induced contraction of rabbit BA rings. A specific inhibitor of EGFR PTK, AG1478, inhibited ET-1—induced EGFR—PTK transactivation, ERK1/2 stimulation, and contraction of BA rings in a concentration-dependent manner. The concentration of AG1478 required for 50% inhibition of the ET-1—induced contraction of BA rings was similar to that for ET-1—induced EGFR—PTK transactivation. Furthermore, AG1478 also inhibited ET-1—induced BA vasospasm in vivo.

Conclusion.The results indicate that EGFR—PTK transactivation pathway plays an important role in ET-1—induced vascular contraction.
Intrinsic brainstem choroid plexus papilloma
Authors: Pillai Ashok , Rajeev Kariyattil , Chandi Sushil , Unnikrishnan Muthukuttiparambil
Published: May 2009

✓ The authors report an intrinsic brainstem lesion that was diagnosed initially as a pontine cavernoma, which finally proved to be a choroid plexus papilloma. Choroid plexus papillomas are rare tumors of the central nervous system and are usually intraventricular in location. The occurrence of this tumor in an intraparenchymal location is extremely rare, and its occurrence within the brainstem is previously unreported. The authors also report a trial of chemotherapy with lomustine in the management of the residual tumor.
Devastating complications from alcohol cauterization of recurrent Rathke cleft cyst
Authors: Hsu Hugo Y. , Piva Alfio , Sadun Alfredo A.
Published: May 2009

✓ Rathke cleft cysts are commonly found on autopsy but are seldom symptomatic. Conventional treatment of these lesions consists of transsphenoidal drainage with partial excision of the cyst, and recurrence is rare. Alternatively, the instillation of absolute alcohol into the cyst has been described in several reports, with no complications. The authors report on a woman with Rathke cleft cyst that recurred three times after the initial treatment; the lesion was treated with alcohol cauterization on the final recurrence with devastating complications.

This 51-year-old woman presented in 1992 with headaches and visual disturbances. Admission magnetic resonance imaging revealed a sellar/suprasellar lesion that was treated with conventional surgery and was subsequently confirmed to be a Rathke cleft cyst. The patient again presented with recurrence of the cyst at 22, 26, and 31 months after the initial presentation. On the final recurrence the cyst was treated with alcohol cauterization. Postoperatively, the patient awoke blind and suffered a seizure from leakage of the alcohol. The patient remains completely blind in both eyes and is also anosmic and has left lid ptosis and exotropia, which signify damage to the first through third cranial nerves.

Rathke cleft cysts have been known to recur after primary surgery; however, this is the first report of a single cyst recurring three times despite conventional surgical treatment. Additionally, this is the first report in which devastating complications from alcohol cauterization of the cyst have been described. The authors therefore advocate caution when attempting alcohol cauterization and advise that meticulous care be taken to ensure the patency of the cyst.
Anterolateral thigh fasciocutaneous flap for simultaneous reconstruction of refractory scalp and dural defects
Authors: Heller Frank , Hsu Chia-Ming , Chuang Chi-Cheng , Wei Kuo-Chen , Wei Fu-Chan
Published: May 2009

✓ Infected full-thickness defects of the calvaria including the scalp, cranial bone, and dura mater, are often refractory to treatment and pose a difficult and urgent therapeutic problem for reconstructive surgeons. The authors report two cases in which successful reconstruction was achieved in one stage by using an anterolateral thigh fasciocutaneous flap. The well-vascularized fascia components were used to repair the infected dural defects. The skin flaps were used for coverage reconstruction.
To everything there is a season and a time to every purpose: retirement and the neurosurgeon
Authors: Rovit Richard L.
Published: May 2009

✓ Neurosurgery has designed a rigid curriculum that must be followed precisely by those who wish to enter the specialty. A similar process at the other end of the practice cycle has never been formalized except for mandatory retirement from certain administrative positions at a particular age. Basic considerations for strategic decision making about voluntary retirement from neurosurgery, especially operative neurosurgery, are investigated.

Statistical data from the US Census Bureau and sources in the medical literature were reviewed regarding life expectancy and retirement ages. Age-related differences in verbal and performance intelligence quotients, attention span, verbal memory recall, and visuospatial facility were surveyed. A questionnaire was sent to 29 recently retired academic neurosurgeons about their age and reasons for retirement along with postretirement activities; 22 responses were received.

Analysis of the data indicates that surgeons are now retiring at the age of approximately 60 years, whereas life expectancy is approximately 80 years. An individual thus may have 15 to 20 productive years after leaving active neurosurgical practice. Reasons for retirement among the 22 responding neurosurgeons included decreasing personal satisfaction and financial rewards, a desire to pursue other activities, local ground rules mandating age-specific retirement, the general sense that enough is enough, and, overall, a strong desire to stop performing surgery while at the top of one's game. The process of age-related competence assessment of commercial airline pilots is outlined, and a similar process of assessment of practicing surgeons may be warranted, with consideration for mandatory retirement from operative neurosurgery.
Selective disconnection of cortical venous reflux as treatment for cranial dural arteriovenous fistulas
Authors: van Dijk J. Marc C. , TerBrugge Karel G. , Willinsky Robert A. , Wallace M. Christopher
Published: May 2009

Object. A single-institution series of 119 consecutive patients with a dural arteriovenous fistula (DAVF) and cortical venous reflux was reviewed to assess the overall clinical outcome of multidisciplinary management after long-term follow up. The selective disconnection of the cortical venous reflux compared with the obliteration of the entire DAVF was evaluated.

Methods. Dural arteriovenous fistulas in patients in this series were diagnosed between 1984 and 2001, and treatment was instituted in 102 of them. The outcome of adequately treated patients was compared with that of a control group consisting of those with persistent cortical venous reflux and with data found in the literature. In cases of combined dural sinus drainage and cortical venous reflux, a novel treatment concept of selective disconnection of the cortical venous reflux that left the sinus drainage intact, and thus converted the aggressive DAVF into a benign lesion, was evaluated.

Endovascular treatment, which was instituted initially in 78 patients, resulted in an obliteration or selective disconnection in 26 (25.5%) of 102 cases. In 70 cases (68.6%) the DAVFs were surgically obliterated or disconnected. In six cases (5.9%), patients were left with persistent cortical venous reflux. No lasting complications were noted in this series. Follow-up angiography confirmed a durable result in 94 (97.9%) of 96 adequately treated cases, at a mean follow up of 27.6 months (range 1.4–138.3 months).

Selective disconnection was performed in 23 DAVFs with combined sinus drainage and cortical venous reflux. These patients' long-term outcomes were equal to those with obliterated DAVFs, and the complication rate was lower.

Conclusions. Considering the ominous course of DAVFs with patent cortical venous reflux, multidisciplinary treatment of these lesions is highly effective and the complication rate is low. Selective disconnection provides a valid treatment option of DAVFs with combined dural sinus drainage and cortical venous reflux, as has been shown in cranial DAVFs with direct cortical venous reflux.
Unilateral stimulation of the subthalamic nucleus in Parkinson disease: a double-blind 12-month evaluation study
Authors: Germano Isabelle M. , Gracies Jean-Michel , Weisz Donald J. , Tse Winona , Koller William C. , Olanow C. Warren
Published: May 2009

Object. Bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been established as an effective treatment for Parkinson disease (PD). Nevertheless, bilateral surgical procedures can be associated with frequent and severe complications. The aim in the present study was to assess the safety and efficacy of unilateral STN stimulation, and the need for a second procedure.

Methods. Twelve patients with PD underwent unilateral DBS of the STN and were followed up for 12 months. Patients were assessed at baseline and at each visit in a double-blind fashion by analyzing the Unified PD Rating Scale (UPDRS), ambulation speed, and home diaries.

Levodopa-off/stimulation-on UPDRS motor scores were improved by 26 ± 8% (p < 0.05, mean ± standard deviation [SD]) compared with the baseline levodopa-off score; there was a 50% improvement in contralateral features, a 17% improvement ipsilaterally, and a 36% improvement in axial features. The mean ambulation speed increased by 83 ± 44% (p < 0.01, mean ± SD). The medication-on time with dyskinesias was significantly reduced (p < 0.01) and the daily levodopa dose was reduced by 19 ± 6% (p < 0.05, mean ± SD). There were no clinically significant side effects.

Conclusions. Unilateral DBS of the STN is safe and well tolerated, and may provide sufficient benefit so that additional surgery is not required.
Diffusion-tensor imaging—guided tracking of fibers of the pyramidal tract combined with intraoperative cortical stimulation mapping in patients with gliomas
Authors: Berman Jeffrey I. , Berger Mitchel S. , Mukherjee Pratik , Henry Roland G.
Published: May 2009

Object. The goal of this study was to use diffusion-tensor (DT) magnetic resonance (MR) imaging to track fibers combined with cortical stimulation mapping to delineate descending motor pathways. Subcortical localization of motor pathways in relation to a glioma may provide critical information to guide tumor resection and prevent surgical morbidity.

Methods. Eleven adult patients harboring gliomas underwent MR imaging 1 day prior to image-guided intraoperative cortical motor mapping and tumor resection. Screens depicting 27 cortical motor sites on a surgical navigation system were saved to launch DT imaging of fiber tracks of descending motor pathways. The position and organization of motor tracts were visualized by fiber tracking. Tracks from 16 motor stimulation sites followed descending pathways from the precentral gyrus, through the corona radiata and internal capsule, and into the cerebral peduncle. These tracks were also observed on DT images to diverge along crossing white matter bundles (four patients) and to terminate or deviate in regions of peritumoral vasogenic edema (five patients).

Conclusions. The use of precise intraoperative cortical mapping information and DT images of fiber tracks can reveal the course of motor pathways beneath the cortex. The subcortical fiber tracks generated are consistent with the known anatomical course and somatotopic organization of the motor tract in relation to its cortical origins. Tracking fibers by using DT imaging in combination with functional localization has the potential to reduce surgical morbidity by revealing subcortical connections of the functional cortex.