bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased regional cerebral blood flow in the contralateral thalamus after successful motor cortex stimulation in a patient with poststroke pain
Authors: Saitoh Youichi , Osaki Yasuhiro , Nishimura Hiroshi , Hirano Shun-ichiro , Kato Amami , Hashikawa Kazuo , Hatazawa Jun , Yoshimine Toshiki
Published: May 2009

✓ The mechanisms underlying poststroke pain have not been clearly identified. Although motor cortex stimulation (MCS) sometimes reduces poststroke pain successfully, the exact mechanism is not yet known. For further investigation of the neural pathways involved in the processing of poststroke pain and in pain reduction by MCS, the authors used positron emission tomography (PET) scanning to determine significant changes in regional cerebral blood flow (rCBF).

This 58-year-old right-handed man suffered from right-sided poststroke pain for which he underwent implantation of a stimulation electrode in the right motor cortex. After 30 minutes of stimulation, his pain was remarkably reduced (Visual Analog Scale scores decreased 8 to 1) and he felt warmth in his left arm. The rCBF was studied using PET scanning with 15O-labeled water when the patient was in the following states: before MCS (painful condition, no stimulation) and after successful MCS (painless condition, no stimulation). The images were analyzed using statistical parametric mapping software. State-dependent differences in global blood flow were covaried using analysis of covariance. Comparisons of the patient's rCBF in the painful condition with that in the painless condition revealed significant rCBF increases in the left rectus gyrus (BA11), left superior frontal lobe (BA9), left anterior cingulate gyrus (BA32), and the left thalamus (p < 0.05, corrected). On the other hand, there were significant decreases in rCBF in the right superior temporal gyrus (BA22, p < 0.01, corrected) and the left middle occipital gyrus (BA19, p < 0.05, corrected).

The efficacy of MCS was mainly related to increased synaptic activity in the thalamus, whereas the activations in the rectus gyrus, anterior cingulate gyrus, and superior frontal cortex as well as the inactivation of the superior temporal lobe may be related to emotional processes. This is the first report in which the contralateral thalamus was significantly activated and pain relief was achieved using MCS.
Intrapelvic and thigh-level femoral nerve lesions: management and outcomes in 119 surgically treated cases
Authors: Kim Daniel H. , Murovic Judith A. , Tiel Robert L. , Kline David G.
Published: May 2009

Object.The authors present a retrospective analysis of 119 surgically treated femoral nerve lesions at intrapelvic and thigh levels seen at the Louisiana State University Health Sciences Center.

Methods.Femoral nerve lesions treated between 1967 and 2000, (89 traumatic injuries and 30 tumors and cystic lesions) were evaluated for injury mechanisms, resulting lesions, surgical management, and postoperative functional outcomes by using retrospective chart reviews.

The most common injury mechanism was iatrogenic (52 cases), which occurred after hernia and hip operations (10 each), followed by arterial bypass and gynecological procedures (eight each), angiography (seven), abdominal surgery (five), appendectomy (two), a laparoscopy, and a lumbar sympathectomy. Other injury mechanisms included hip or pelvic fractures (19), gunshot wounds (10), and lacerations (eight). The 30 femoral nerve tumors and cystic lesions consisted of neurofibromas (16), schwannomas (nine), ganglionic cysts (two), neurogenic sarcomas (two), and a leiomyosarcoma.

Forty-four patients underwent neurolysis. Some had recordable nerve action potentials (NAPs) across their lesions in continuity, despite severe distal loss. Others with recordable NAPs had mild loss, but also experienced a pain problem, which was helped in some by neurolysis. In 36 patients, in whom repairs were performed using long sural grafts for mostly proximal pelvic-level injuries, recovery of useful function occurred. Eight of nine thigh-level suture repairs led to improvement to good functional levels. Most of the tumors and cystic lesions were resected, with preservation of preoperative function.

Conclusions.The majority of femoral nerve injuries resulted in lesions in continuity, and intraoperative NAP recordings were essential in evaluating axonal regeneration across these lesions. Despite severe and frequently proximal injury levels requiring repairs with long grafts, femoral nerve lesion repairs resulted in good functional recovery.
Radiation-induced meningiomas: clinical, pathological, cytokinetic, and cytogenetic characteristics
Authors: Al-Mefty Ossama , Topsakal Cahide , Pravdenkova Svetlana , Sawyer Jeffrey R. , Harrison Michael J.
Published: May 2009

Object. Radiation-induced meningiomas are known to occur after high- and low-dose cranial radiation therapy. The goal of this study was to discern the distinguishing findings and characteristics of radiation-induced meningiomas.

Methods. The records of 16 patients (seven men and nine women) who fulfilled the criteria for radiation-induced meningiomas were retrospectively reviewed. Clinical, histopathological, cytokinetic, and cytogenetic findings as well as the patients' outcome were analyzed.

The mean age of the patients was 38.8 years and the mean tumor latency was 26.5 years. Five patients had multiple meningiomas in the irradiated field. The recurrence rate was 100% after the initial resection; 62% of patients had a second recurrence and 17% had a third recurrence. Thirty-eight percent of patients had atypical or malignant histopathological findings. The presence of progesterone receptors and low proliferation indices in these patients did not correlate with benign tumor behavior. Cytogenetic analysis showed multiple clonal aberrations in all tumors studied. The most frequent aberrations were found on chromosomes 1p, 6q, and 22. Derivative, lost, or additional chromosome 1p was found in 89% of cases and loss or deletion on chromosome 6 was found in 67%.

Conclusions. The age of patients at presentation with meningioma and the latency period of radiation-induced meningiomas are dose related. These tumors are more aggressive and are certain to recur, have a higher histopathological grade, and are associated with complex cytogenetic aberrations particularly involving 1p and 6q.
Meningiomas of the posterior petrous bone: functional outcome after microsurgery
Authors: Bassiouni Hischam , Hunold Anja , Asgari Siamak , Stolke Dietmar
Published: May 2009

Object.The aim of this study was to analyze a subgroup of patients harboring cerebellopontine angle meningiomas originating from the posterior petrous bone in regard to clinical presentation, surgical anatomy, complications, and long-term functional postoperative results.

Methods.Data in a series of 51 patients with meningiomas of the posterior petrous bone who had undergone microsurgical treatment at the authors' institution between 1989 and 2002 were retrospectively reviewed. The patient population consisted of 46 women and five men with a mean age of 53 years (range 22–70 years). The main symptom on first admission was impaired hearing in 41%, dizziness in 20%, and tinnitus in 18% of the patients. Results of physical examination and audiological testing revealed hypacusis in 65% of patients, cerebellar ataxia in 31%, and impairment of the fifth cranial nerve in 26%. All patients underwent surgical treatment via a lateral suboccipital approach. Intraoperatively, the tumor was found to be attached to the postmeatal dura in 37%, the premeatal dura in 27.5%, the suprameatal dura in 19.6%, the inframeatal dura in 7.8%, and centered on the porus acusticus in 5.9% of cases. Tumor extension into the internal acoustic meatus was present in seven patients. Tumor resection was categorized as Grade I in 14 patients, Grade II in 29, Grade III in six, and Grade IV in two patients, according to the Simpson classification system. The site of displacement of the cranial nerves was predictable in up to 84% of patients, depending on the dural origin of the tumor as depicted on preoperative magnetic resonance (MR) imaging studies. Postoperatively, a new and permanent facial paresis was observed in five patients (9.8%). In 38 patients in whom both pre- and postoperative audiological data were available, hearing function deteriorated after surgery in 18.4% and improved in 7.9%. Clinical and MR imaging postsurgical data from a mean period of 5.8 years (range 13 months–13 years) were available in all patients. Forty-four patients (86%) resumed normal daily activity. Tumor recurrence was observed in two patients (3.9%), and both underwent a second surgery.

Conclusions.Preoperative detailed analysis of MR imaging data gives the surgeon a clue about the dislocation of critical neurovascular structures, particularly the cranial nerves. Nonetheless, the exact relationship of the cranial nerves to the tumor (dislocation, adherence, infiltration, and splaying of nerves) can only be fully appreciated during surgery.
Successful treatment of a ruptured dissecting basilar artery aneurysm
Authors: Kai Yutaka , Hamada Jun-ichiro , Morioka Motohiro , Yano Shigetoshi , Hamasaki Kiyotoshi , Ushio Yukitaka
Published: May 2009

✓ Dissecting basilar artery (BA) aneurysms in patients presenting with subarachnoid hemorrhage are life threatening, especially in those who experience subsequent bleeding or progressive dissection, and immediate surgical or endovascular intervention may be necessary. The authors report on a 52-year-old woman whose dissecting BA aneurysm was treated successfully with proximal occlusion and flow reversal. Clipping of the proximal BA above the level of the anterior inferior cerebellar arteries facilitated retrograde flow from a radial artery graft placed between the left vertebral artery and the left posterior cerebral artery, thereby providing continuous perfusion of the BA and its branches. Postoperative angiograms obtained 1 year later revealed good retrograde flow through the BA and dilation of the radial arterial graft. There were no episodes of recurrent hemorrhage.
Effect of subthalamic nucleus stimulation on obsessive—compulsive disorder in a patient with Parkinson disease
Authors: Fontaine Denys , Mattei Vianney , Borg Michel , von Langsdorff Daniel , Magnie Marie-Noelle , Chanalet Stéphane , Robert Philippe , Paquis Philippe
Published: May 2009

✓ The authors report on a patient with Parkinson disease (PD) and severe obsessive—compulsive disorder (OCD), in whom bilateral stimulation of the subthalamic nucleus (STN) was used to treat both PD and OCD symptoms.

This 49-year-old man had displayed symptoms of PD for 13 years. Progressively, his motor disability became severe despite optimal medical treatment. In parallel, he suffered severe OCD for 16 years, with obsessions of accumulation and compulsions of gathering and rubbing that lasted more than 8 hours per day. Bilateral high-frequency STN stimulation was performed to treat motor disability. After surgery (at 1-year follow up), motor and OCD symptoms were dramatically improved. The pre- and postoperative Yale—Brown Obsessive—Compulsive Scale scores were 32 and 1, respectively. No additional antiparkinsonian drugs were administered.

This case and other recent reports indicate that OCD symptoms can be improved by deep brain stimulation, a finding that opens new perspectives in the surgical treatment of severe and medically intractable OCD.
Pharmacokinetics of controlled-release polymers in the subarachnoid space after subarachnoid hemorrhage in rabbits
Authors: Pradilla Gustavo , Wang Paul P. , Legnani Federico G. , Frazier James L. , Tamargo Rafael J.
Published: May 2009

Object.Implantation of controlled-release polymers into the subarachnoid space to deliver drugs for treatment of vasospasm after subarachnoid hemorrhage (SAH) is currently of interest. Among the issues regarding local delivery of drugs in the subarachnoid space, however, are the extent of diffusion and the rate of release of the loaded agents. In this study Evans blue dye (EBD) was loaded into controlled-release polymers and its pharmacokinetic properties were determined in vitro and in vivo by using a rabbit model of SAH.

Methods.Ethylene—vinyl acetate copolymer (EVAc) was loaded 40% (w:w) with EBD and its pharmacokinetics were spectrophotometrically determined in vitro by examining three EBD—EVAc polymers. Additional polymers were implanted either into the frontal lobe or into the cisterna magna of 16 New Zealand White rabbits. Subarachnoid hemorrhage was induced in eight of the animals by an injection of 1.5 ml of arterial blood into the cisterna magna. The animals were killed 3 or 14 days postoperatively, their brains and spinal cords were harvested, and samples of each were placed in formamide for dye extraction and quantification. Specimens were examined macroscopically and the concentrations of EBD were determined with the aid of a spectrophotometer.

The EBD—EVAc polymers continuously released EBD over a 133-day period. The controlled release of the dye into the subarachnoid space in either location resulted in staining of the entire central nervous system (CNS) in rabbits when the polymers were placed either on the frontal lobe or in the cisterna magna. The EBD diffusion covered a distance of at least 40 cm. The presence of blood in the subarachnoid space did not interfere with the diffusion.

Conclusions.In this study the authors define the rate and extent of diffusion of EBD from controlled-release polymers placed in the subarachnoid space under conditions of SAH. Evans blue dye diffused through the entire rabbit CNS, covering a distance greater than that of the longest dimension of the hemicircumference of the subarachnoid space around the human brain. The pharmacokinetic properties of EBD—EVAc polymers are comparable to those of antivasospasm agents that are successfully used in animal models of SAH.
Ruptured “blisterlike” aneurysm with a pseudoaneurysm formation requiring delayed intervention with endovascular coil embolization
Authors: Tanoue Shuichi , Kiyosue Hiro , Matsumoto Shunro , Yamashita Masanori , Nagatomi Hirofumi , Mori Hiromu
Published: May 2009

✓ A ruptured blisterlike aneurysm of the supraclinoid ICA rarely occurs. Nevertheless, it is recognized as a dangerous lesion because of the high risk of intraoperative bleeding associated with this lesion's wide fragile neck. There has been only one report of a blisterlike aneurysm treated by endosaccular packing after surgical wrapping. The authors describe the case of a ruptured blisterlike aneurysm with a pseudoaneurysm cavity, which was treated by coil embolization.

This 63-year-old woman suffered a subarachnoid hemorrhage (SAH). Three cerebral aneurysms were identified on cerebral angiograms. A large saccular aneurysm at the ophthalmic portion of the right ICA was embolized with Guglielmi Detachable Coils (GDCs). Two small hemipherically shaped aneurysms on the C-2 and C-3 portions of the left ICA were observed conservatively. Thirteen days later, recurrent SAH was identified on computerized tomography scans. Angiography demonstrated the formation of a pseudoaneurysm from the aneurysm on the C-2 portion of the left ICA. Endosaccular embolization with GDCs was performed 40 days after admission. Disappearance of the pseudoaneurysm cavity and residual dome filling was seen immediately after the procedure. Follow-up angiography performed 9 months after embolization demonstrated complete obliteration of the aneurysm.

This case illustrates that when treatment options for a blisterlike aneurysm with a pseudoaneurysm are unsuitable during the acute phase, coil embolization can be applied following progression of the lesion into a saccular aneurysm during the chronic stage.
Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results
Authors: Coubes Philippe , Cif Laura , El Fertit Hassan , Hemm Simone , Vayssiere Nathalie , Serrat Stephanie , Picot Marie Christine , Tuffery Sylvie , Claustres Mireille , Echenne Bernard , Frerebeau Philippe
Published: May 2009

Object. Primary generalized dystonia (PGD) is a medically refractory disease of the brain causing twisting or spasmodic movements and abnormal postures. In more than 30% of cases it is associated with the autosomal DYT1 mutation. Continuous electrical stimulation of the globus pallidus internus (GPi) has been used successfully in the treatment of PGD. The aim of this study was to examine the long-term efficacy and safety of deep brain stimulation (DBS) in the treatment of PGD in children and adults with and without the DYT1 mutation.

Methods. Thirty-one patients with PGD were selected for surgery. Electrodes were bilaterally implanted under stereotactic guidance and connected to neurostimulators that were inserted subcutaneously. Efficacy was evaluated by comparing scores on the clinical and functional Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) before and after implantation.

The efficacy of stimulation improved with time. After 2 years, compared with preoperative values, the mean (± standard deviation) clinical and functional BFMDRS scores had improved by 79 ± 19% and 65 ± 33%, respectively. At the 2-year follow-up examination the improvement was comparable in patients with and without the DYT1 mutation in both the functional (p = 0.12) and clinical (p = 0.33) scores. Children displayed greater improvements in the clinical score than adult patients (p = 0.04) at 2 years of follow up. In contrast, there was no significant difference in functional scores between children and adults (p = 0.95).

Conclusions. Electrical stimulation of the GPi is an effective, reversible, and adaptable treatment for PGD and should be considered for conditions refractory to pharmaceutical therapies.
The influence of sex and the presence of giant cells on postoperative long-term survival in adult patients with supratentorial glioblastoma multiforme
Authors: Shinojima Naoki , Kochi Masato , Hamada Jun-Ichiro , Nakamura Hideo , Yano Shigetoshi , Makino Keishi , Tsuiki Hiromasa , Tada Kenji , Kuratsu Jun-Ichi , Ishimaru Yasuji , Ushio Yukitaka
Published: May 2009

Object. Glioblastoma multiforme (GBM) remains incurable by conventional treatments, although some patients experience long-term survival. A younger age, a higher Karnofsky Performance Scale (KPS) score, more aggressive treatment, and long progression-free intervals have been reported to be positively associated with long-term postoperative patient survival. The aim of this retrospective study was the identification of additional favorable prognostic factors affecting long-term survival in surgically treated adult patients with supratentorial GBM.

Methods. Of 113 adult patients newly diagnosed with histologically verified supratentorial GBM who were enrolled in Phase III trials during the period between 1987 and 1998, six (5.3%) who survived for longer than 5 years were defined as long-term survivors, whereas the remaining 107 patients served as controls. All six were women and were compared with the controls; they were younger (mean age 44.2 years, range 31–60 years), and their preoperative KPS scores were higher (mean 85, range 60–100). Four of the six patients underwent gross-total resection. In five patients (83.3%) the progression-free interval was longer than 5 years and in three a histopathological diagnosis of giant cell GBM was made. This diagnosis was not made in the other 107 patients.

Conclusions. Among adult patients with supratentorial GBM, female sex and histopathological characteristics consistent with giant cell GBM may be predictive of a better survival rate, as may traditional factors (that is, younger age, good KPS score, more aggressive resection, and a long progression-free interval).
Functional impairment, disability, and quality of life outcome after decompressive hemicraniectomy in malignant middle cerebral artery infarction
Authors: Foerch Christian , Lang Josef M. , Krause Jochen , Raabe Andreas , Sitzer Matthias , Seifert Volker , Steinmetz Helmuth , Kessler Kirn R.
Published: May 2009

Object. Whether decompressive hemicraniectomy is an appropriate treatment for space-occupying middle cerebral artery (MCA) infarction is still a controversial issue. Previous studies are in agreement on a reduction of the mortality rate, but the reported functional outcome was highly variable. The authors sought to determine functional impairment, disability, and health-related quality of life (QOL) outcome in long-term survivors who had undergone this procedure, and tried to identify factors related to functional outcome.

Methods. The study included 36 consecutive patients (mean age 58.8 ± 12.7 years, 20 men and 16 women) who underwent decompressive hemicraniectomy for treatment of malignant MCA infarction (29 on the right and seven on the left side; mean time to surgery 37.8 ± 20 hours). The survival rate was determined at 6 months: 13.7 ± 6.7 months after the stroke, a cross-sectional personal investigation of survivors was performed to assess functional impairment, disability, and health-related QOL.

Survival rates were 78% at 6 months and 64% at the time of the follow-up investigation; one patient was lost to follow up. Sixteen of 22 long-term survivors lived at home. The median Barthel Index (BI) was 45 (25th and 75th percentile 19 and 71) and the BI correlated negatively with patient age (r = −0.58, p = 0.005). Three patients reached a BI of at least 90. Older age, more severe neurological deficit on admission, and longer duration of intensive care treatment and mechanical ventilation were significantly associated with worse disability (BI < 50). The health-related QOL was considerably impaired in the subscales of mobility, household management, and body care.

Conclusions. Decompressive hemicraniectomy improves survival in patients with malignant MCA infarction when compared with earlier reports of conservative treatment alone. Functional outcome and QOL remain markedly impaired, especially among elderly patients and in those with a severe neurological deficit at admission.
Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage
Authors: Reilly Christopher , Amidei Chris , Tolentino Jocelyn , Jahromi Babak S. , Macdonald R. Loch
Published: May 2009

Object. This study was conducted for two purposes. The first was to determine whether a combination of measurements of subarachnoid clot volume, clearance rate, and density could improve prediction of which patients experience vasospasm. The second was to determine if each of these three measures could be used independently to predict vasospasm.

Methods. Digital files of the cranial computerized tomography (CT) scans obtained in 75 consecutive patients admitted within 24 hours of subarachnoid hemorrhage (SAH) were analyzed in a blinded fashion by an observer who used quantitative imaging software to measure the volume of SAH and its density. Clot clearance rates were measured by quantifying SAH volume on subsequent CT scans. Vasospasm was defined as new onset of a focal neurological deficit or altered consciousness 5 to 12 days after SAH in the absence of other causes of deterioration, diagnosed with the aid of or exclusively by confirmatory transcranial Doppler ultrasonography and/or cerebral angiography.

Univariate analysis showed that vasospasm was significantly associated with the SAH grade as classified on the Fisher scale, the initial clot volume, initial clot density, and percentage of clot cleared per day (p < 0.05). In multivariate analysis, initial clot volume and percentage of clot cleared per day were significant predictors of vasospasm (p < 0.05), whereas Fisher grade and initial clot density were not.

Conclusions. Quantitative analysis of subarachnoid clot shows that vasospasm is best predicted by initial subarachnoid clot volume and the percentage of clot cleared per day.
Integration of biochemical images of a tumor into frameless stereotaxy achieved using a magnetic resonance imaging/magnetic resonance spectroscopy hybrid data set
Authors: Stadlbauer Andreas , Moser Ewald , Gruber Stephan , Nimsky Christopher , Fahlbusch Rudolf , Ganslandt Oliver
Published: May 2009

Object. It is often difficult to delineate the extent of invasion of high- and low-grade gliomas into normal brain tissue by using conventional T1- and T2-weighted magnetic resonance (MR) imaging. Knowledge of the relationship between the tumor infiltration zone and normal brain, however, is one of the prerequisites for performing as radical a tumor resection as possible. Proton MR spectroscopy allows noninvasive measurements of the concentrations and spatial distributions of brain metabolites and, therefore, may provide biochemical information in vivo, that is useful in distinguishing pathological from normal areas of the brain.

The authors have developed a method to use the properties of MR spectroscopy to investigate intraoperatively pathological changes in the spatial distribution of choline (Cho)-containing compounds, total creatine, and N-acetylaspartate (NAA) in brain tumors with the aid of frameless stereotaxy.

Methods. Maps of the Cho/NAA ratio were calculated and automatic segmentation of the tumors was performed. Spectroscopic images of the segmented tumor were matched to an anatomical three-dimensional (3D) MR imaging set by applying a fully automated mutual-information algorithm. The resulting 3D MR image can be used subsequently for neurosurgical planning, transfer to a frameless stereotactic system, and display in the navigation microscope during surgery leading to 1H-MR spectroscopy-guided navigation.

Conclusions. This method may allow better intraoperative identification of tumor border zones based on metabolic changes due to tumor infiltration.
A realistic brain tissue phantom for intraparenchymal infusion studies
Authors: Chen Zhi-Jian , Gillies George T. , Broaddus William C. , Prabhu Sujit S. , Fillmore Helen , Mitchell Ryan M. , Corwin Frank D. , Fatouros Panos P.
Published: May 2009

Object. The goal of this study was to validate a simple, inexpensive, and robust model system to be used as an in vitro surrogate for in vivo brain tissues in preclinical and exploratory studies of infusion-based intraparenchymal drug and cell delivery.

Methods. Agarose gels of varying concentrations and porcine brain were tested to determine the infusion characteristics of several different catheters at flow rates of 0.5 and 1 µl per minute by using bromophenol blue (BPB) dye (molecular weight [MW] ∼690) and gadodiamide (MW ∼573). Magnetic resonance (MR) imaging and videomicroscopy were used to measure the distribution of these infusates, with a simultaneous measurement of infusion pressures. In addition, the forces of catheter penetration and movement through gel and brain were measured.

Agarose gel at a 0.6% concentration closely resembles in vivo brain with respect to several critical physical characteristics. The ratio of distribution volume to infusion volume of agarose was 10 compared with 7.1 for brain. The infusion pressure of the gel demonstrated profiles similar in configuration and magnitude to those of the brain (plateau pressures 10–20 mm Hg). Gadodiamide infusion in agarose closely resembled that in the brain, as documented using T1-weighted MR imaging. Gadodiamide distribution in agarose gel was virtually identical to that of BPB dye, as documented by MR imaging and videomicroscopy. The force profile for insertion of a silastic catheter into agarose gel was similar in magnitude and configuration to the force profile for insertion into the brain. Careful insertion of the cannula using a stereotactic guide is critical to minimize irregularity and backflow of infusate distribution.

Conclusions. Agarose gel (0.6%) is a useful surrogate for in vivo brain in exploratory studies of convection-enhanced delivery.
Shunt-dependent hydrocephalus after rupture of intracranial aneurysms: a prospective study of the influence of treatment modality
Authors: Dehdashti Amir R. , Rilliet Bénédict , Rufenacht Daniel A. , de Tribolet Nicolas
Published: May 2009

Object. This study was designed to determine whether the frequency of shunt-dependent hydrocephalus in patients suffering from aneurysmal subarachnoid hemorrhage (SAH) differs when comparing surgical clip application with endovascular obliteration of ruptured aneurysms.

Methods. In this prospective nonrandomized study, 245 patients with aneurysmal SAH treated using either surgical clip application or endovascular coil embolization were studied at our institution between September 1997 and March 2003. One hundred eighty patients underwent clip application and 65 had coil embolization. In those patients who underwent clip application of anterior circulation aneurysms, the lamina terminalis was systematically fenestrated.

The occurrence of acute, asymptomatic, and shunt-dependent hydrocephalus was analyzed in both treatment groups. A subgroup analysis of patients with good clinical grade (World Federation of Neurosurgical Societies [WFNS] Grades I–III) and better Fisher Grade (1–3) and of patients with Fisher Grade 4 hemorrhage was performed.

Acute hydrocephalus was observed in 19% of surgical cases and 46% of endovascular ones. The occurrence of asymptomatic hydrocephalus was similar in both treatment groups (p = 0.4). Shunt-dependent hydrocephalus occurred in 14% of surgical cases and 19% of endovascular cases. This difference did not reach statistical significance (p = 0.53). Logistic regression models controlling for patient age, WFNS grade, Fisher grade, and acute hydrocephalus in patients with good clinical grade and better Fisher grade revealed no significant difference in the rate of shunt-dependent hydrocephalus in both therapy groups (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.2–2.65). Results of similar models indicated that among patients with intraventricular hemorrhage (IVH), surgical clip application carried a lower risk of shunt-dependent hydrocephalus (OR 0.32, 95% CI 0.14–0.75) compared with that for endovascular embolization.

Conclusions. Shunt-dependent hydrocephalus was comparable in the two treatment groups, even in patients with better clinical and radiological grades on admission. Only patients in the endovascular therapy group who had experienced IVH showed a higher likelihood of shunt-dependent hydrocephalus.
Detailed anatomy of the motor and sensory roots of the trigeminal nerve and their neurovascular relationships: a magnetic resonance imaging study
Authors: Yousry Indra , Moriggl Bernhard , Holtmannspoetter Markus , Schmid Urs D. , Naidich Thomas P. , Yousry Tarek A.
Published: May 2009

Object. The trigeminal nerve conducts both sensory and motor impulses. Separate superior and inferior motor roots typically emerge from the pons just anterosuperomedial to the entry point of the sensory root, but to date these two motor roots have not been adequately displayed on magnetic resonance (MR) images. The specific aims of this study, therefore, were to identify the superior and inferior motor roots, to describe their exact relationship to the sensory root, and to assess the neurovascular relationships among all three roots of the trigeminal nerve.

Methods. Thirty-three patients and seven cadaveric specimens (80 sides) were studied using three-dimensional (3D) Fourier transform constructive interference in steady-state (CISS) imaging. The 33 patients were also studied by obtaining complementary time-of-flight (TOF) MR angiography sequences with and without contrast enhancement.

At least one motor root was identified in all sides examined: in 51.2% of the sides a single motor root, in 37.5% two motor roots, and in 11.2% three motor roots. The superior cerebellar artery (SCA) and the anterior inferior cerebellar artery (AICA) contacted the sensory root in 45.5% of patients and 42.9% of specimens. The SCA often contacted the superior motor root (48.5% of patients and 50% of specimens) and less frequently the inferior motor root (26.5% of patients and 20% of specimens).

Conclusions. Three-dimensional CISS and complementary 3D TOF MR angiography sequences reliably display sensory, superior motor, and inferior motor roots of the trigeminal nerve and their relationships to the SCA and AICA.
Normobaric hyperoxia—induced improvement in cerebral metabolism and reduction in intracranial pressure in patients with severe head injury: a prospective historical cohort—matched study
Authors: Tolias Christos M. , Reinert Michael , Seiler Rolf , Gilman Charlotte , Scharf Alexander , Bullock M. Ross
Published: May 2009

Object. The effect of normobaric hyperoxia (fraction of inspired O2 [FIO2] concentration 100%) in the treatment of patients with traumatic brain injury (TBI) remains controversial. The aim of this study was to investigate the effects of normobaric hyperoxia on five cerebral metabolic indices, which have putative prognostic significance following TBI in humans.

Methods. At two independent neurointensive care units, the authors performed a prospective study of 52 patients with severe TBI who were treated for 24 hours with 100% FIO2, starting within 6 hours of admission. Data for these patients were compared with data for a cohort of 112 patients who were treated in the past; patients in the historical control group matched the patients in our study according to their Glasgow Coma Scale scores after resuscitation and their intracranial pressure within the first 8 hours after admission. Patients were monitored with the aid of intracerebral microdialysis and tissue O2 probes.

Normobaric hyperoxia treatment resulted in a significant improvement in biochemical markers in the brain compared with the baseline measures for patients treated in our study (patients acting as their own controls) and also compared with findings from the historical control group. In the dialysate the glucose levels increased (369.02 ± 20.1 µmol/L in the control group and 466.9 ± 20.39 µmol/L in the 100% O2 group, p = 0.001), whereas the glutamate and lactate levels significantly decreased (p < 0.005). There were also reductions in the lactate/glucose and lactate/pyruvate ratios. Intracranial pressure in the treatment group was reduced significantly both during and after hyperoxia treatment compared with the control groups (15.03 ± 0.8 mm Hg in the control group and 12.13 ± 0.75 mm Hg in the 100% O2 group, p < 0.005) with no changes in cerebral perfusion pressure. Outcomes of the patients in the treatment group improved.

Conclusions. The results of the study support the hypothesis that normobaric hyperoxia in patients with severe TBI improves the indices of brain oxidative metabolism. Based on these data further mechanistic studies and a prospective randomized controlled trial are warranted.
Functional separation of languages in the bilingual brain: a comparison of electrical stimulation language mapping in 25 bilingual patients and 117 monolingual control patients
Authors: Lucas Timothy H. , McKhann Guy M. , Ojemann George A.
Published: May 2009

Object. The aim of this investigation was to address three questions in bilingualism research: 1) are multiple languages functionally separated within the bilingual brain; 2) are these languages similarly organized; and 3) does language organization in bilinguals mirror that in monolinguals?

Methods. During awake dominant-hemisphere craniotomy in each of 25 bilingual patients, the authors mapped both languages by using identical object-naming stimuli. Essential sites for primary (L1) and secondary (L2) languages were compared. Sites were photographically recorded and plotted onto an anatomically referenced grid system. Language organization in bilinguals was then compared with that in 117 monolinguals and 11 monolingual children.

Conclusions. The authors found distinct language-specific sites as well as shared sites that support both languages. The L1 and L2 representations were similar in total cortical extent but significantly different in anatomical distribution. The L2-specific sites were located exclusively in the posterior temporal and parietal regions, whereas the L1 and shared sites could be found throughout the mapped regions. Bilinguals possessed seven perisylvian language zones, in which L2 sites were significantly underrepresented when compared with the distribution of language sites in monolinguals. These L2-restricted zones overlapped the primary language areas found in monolingual children, indicating that these zones become dedicated to L1 processing. These findings support three conclusions. First, it is necessary to map both languages in bilinguals because L1 and L2 sites are functionally distinct. Second, differences exist in the organization of L1 and L2 sites, with L2-specific sites located exclusively in the posterior temporal and parietal lobes. Third, language organization comparisons in bilingual and monolingual brains demonstrate the presence of L2-restricted zones, which are dedicated to L1.
Application of p27 gene therapy for human malignant glioma potentiated by using mutant p27
Authors: Park Kyung-Ho , Lee Jaeho , Yoo Chul-Gyu , Kim Young Whan , Han Sung Koo , Shim Young-Soo , Kim Seung-Ki , Wang Kyu-Chang , Cho Byung-Kyu , Lee Choon-Taek
Published: May 2009

Object. Malignant glioma could be an ideal candidate for local gene therapy because its invasion is local and it has little metastatic potential. A low expression level and high degradation activity of p27 are known to constitute an independent poor prognostic factor in patients with malignant glioma. In this study, the authors investigated the roles of wild-type p27 and mutant p27 on the treatment of malignant glioma.

Methods. The authors used two adenoviruses: one expressed wild-type p27 (ad-p27wt) and the other, containing a mutation at the major metabolic site, expressed mutant p27 (ad-p27mt). The antitumor effects of the two adenoviruses were compared with respect to cell growth arrest, cell cycle alteration, apoptosis induction, and in vitro tumorigenicity in three glioblastoma mutiforme (GBM) cell lines and in a primary GBM cell line. Transduction with ad-p27wt or ad-p27mt induced the production of p27 and the dephosphorylation of pRB. The protein level of mutant p27 was significantly higher than that of wild-type p27. The ad-p27wt induced cell cycle arrest at the G1—S transition point, whereas the ad-p27mt induced arrest at the G2—M point. Both ad-p27wt and ad-p27mt induced a growth-inhibiting effect, apoptosis, and suppression of in vitro tumorigenicity; however, ad-p27mt displayed a stronger antitumor effect than ad-p27wt in brain tumor cell lines.

Conclusions. Gene therapy involving p27, especially mutant p27, has the potential to become a novel and powerful therapy for malignant glioma.
Endotracheal tube electrodes to map and monitor activities of the vagus nerve intraoperatively
Authors: Mikuni Nobuhiro , Satow Takeshi , Taki Junya , Nishida Namiko , Enatsu Rei , Hashimoto Nobuo
Published: May 2009

✓ Difficulty swallowing due to damage of the vagus nerve is one of the most devastating complications of surgery in and around the medulla oblongata; therefore, intraoperative anatomical and functional evaluation of this nerve is crucial. The authors applied endotracheal tube surface electrodes to record electromyography (EMG) activity from vocal cords innervated by the vagus nerve. The vagal nucleus or rootlet was electrically stimulated during surgery and vocalis muscle EMG activities were displayed by auditory and visual signals. This technique was used successfully to identify the vagus motor nerve and evaluate its integrity during surgery. The advantages of this method compared with the use of needle electrodes include safe simple electrode placement and stable recording during surgery. In cases involving a pontine cavernoma pressing the nucleus or a jugular foramen tumor encircling the rootlet, this method would be particularly valuable. Additional studies with a larger number of patients are needed to estimate the significance of this method as a means of functional monitoring to predict clinical function.
A quiet hand for microneurosurgery: twiddle your thumb
Authors: Ferguson R. Lawrence , Jobe Kirk
Published: May 2009

✓ Fatigue is both the most tremor-producing factor and the constant companion of a busy neurosurgeon. Because of the difficulty in controlling tremor-generating factors, the authors sought to develop a means of manipulating surgical instruments with minimal muscle movement while allowing accurate and repeatable movements in all conditions. The “quiet hand technique” is an isolation technique that creates a stable platform by forming the four fingers into a salute that thenceforth moves as one. Fine movements are supplied by the thumb. For instruments that open and close, the thumb abducts and adducts. For suture placement using a round needle holder, the thumb flexes and extends.

Because only the thumb moves, the extent of movement is decreased and therefore momentum and inertia are limited as well. Previously, microsurgeons favored ballistic movements. With the quiet hand technique, however, tension movements are easy. The greater control makes tying 10-0 and 11-0 sutures more predictable. Although the quiet hand technique was developed for use in small-vessel anastomosis, the neurophysiological principles on which it is based apply to movement at all levels and are applicable to working a bipolar coagulator, pickups, a vascular clip holder, or other soft-tissue manipulators.
Surgery for Rathke cleft cysts: technical considerations and outcomes
Authors: Benveniste Ronald J. , King Wesley A. , Walsh Jane , Lee Jacob S. , Naidich Thomas P. , Post Kalmon D.
Published: May 2009

Object. The aim of this study was to identify the optimal surgical goals and techniques for managing symptomatic Rathke cleft cysts (RCCs).

Methods. The authors conducted a retrospective study of 62 consecutive patients who had undergone surgery for RCCs. Postoperative follow up was a mean of 28 months. Fifty-six patients underwent transsphenoidal cyst decompression and biopsy procedures, and six underwent cyst wall resection. Postoperatively, symptoms improved in 91% of patients with headaches and 92% of patients with visual deficits. Decompression and biopsy were associated with a 10% incidence of new anterior pituitary hormone deficiencies and a 6% incidence of new permanent diabetes insipidus; the incidence of new hormone deficiencies was significantly higher in the few patients who had undergone cyst wall resection. The incidence of relapse, defined as cyst regrowth with either recurrent symptoms or chiasmal compression, was 16%. Resection of the cyst wall was associated with a trend toward a decreased risk of relapse. Sellar packing, sellar floor reconstruction, and irrigation with absolute ethanol did not affect the likelihood of relapse. Squamous metaplasia and inflammation increased the risk of relapse. Residual cyst demonstrated on postoperative magnetic resonance imaging was associated with an increased risk of subsequent asymptomatic cyst regrowth. Seven patients (11%) underwent repeated operation with symptomatic improvement and minimal morbidity; only one patient relapsed following a second surgery.

Conclusions. Decompression and biopsy procedures in the treatment of RCCs lead to improvement in signs and symptoms, with low morbidity rates. Repeated operations will be required in as many as 16% of patients but are also associated with symptomatic improvement, low morbidity, and durable remission. Decompression and biopsy may represent the optimal surgical management of RCC.
Leksell Gamma Knife coordinate setting slippage: how often, how much?
Authors: Foote Robert L. , Pollock Bruce E. , Link Michael J. , Garces Yolanda I. , Kline Robert W.
Published: May 2009

Object. The aim of this study was to determine the incidence and magnitude of coordinate setting slippage during gamma knife surgery (GKS).

Methods. Thirty-six consecutive patients undergoing GKS with a Leksell unit between June and December 2000 had their coordinates (right and left x-, y-, and z-coordinates; 1548 coordinates; 258 isocenters) and gamma angles checked after the delivery of treatment to each isocenter to determine whether the coordinate settings had slipped and, if so, which settings and the magnitude of the slippage.

Conclusions. Coordinate setting slippage during GKS with a Leksell unit does occur but is rare. The magnitude of such slippage is typically within the error of the stereotactic system and coordinate reading. The authors noted that coordinate setting slippage is significantly correlated with patient weight.
Mesial temporal lobe epilepsy: a proton magnetic resonance spectroscopy study and a histopathological analysis
Authors: Cohen-Gadol Aaron A. , Pan Jullie W. , Kim Jung H. , Spencer Dennis D. , Hetherington Hoby H.
Published: May 2009

Object. Proton magnetic resonance (MR) spectroscopy imaging of the ratio of N-acetylaspartate (NAA) to creatine (Cr) has proved efficacious as a localizing tool in demonstrating the metabolic changes associated with temporal lobe epilepsy. To analyze the significance of these MR spectroscopy findings further, the authors explored the relationship between regional alterations in the NAA/Cr ratio in hippocampi measured preoperatively and histopathological findings in hippocampi resected in patients with intractable mesial temporal lobe epilepsy (MTLE).

Methods. Twelve patients in whom the diagnosis of MTLE had been made and 12 healthy volunteers with no known history of neurological disease underwent high-resolution 1H MR spectroscopy imaging of NAA and Cr (0.64 cm3 nominal voxel resolution) in five voxels spanning the anteroposterior length of the hippocampus. The authors correlated the NAA/Cr ratio with neuropathological findings in resected hippocampi, specifically glial fibrillary acidic protein (GFAP) immunoreactivity and pyramidal neuronal loss. A linear regression analysis of the ipsilateral NAA/Cr ratio revealed a statistically significant relation to the extent of hippocampal neuronal loss in only the CA2 sector (correlation coefficient [r] = −0.66, p < 0.03). The ipsilateral NAA/Cr ratio displayed significant regressions with GFAP immunoreactivity from all the CA sectors (r values ranged from −0.69 and p < 0.01 for the CA4 sector to −0.88 and p < 0.001 for the CA2 sector) except for the CA1. The extent of neuronal cell loss in every hippocampal subfield (r = 0.71−0.74, p < 0.007), except the CA2 (p = 0.08), correlated to the extent of neuronal cell loss in the dentate gyrus. There was no significant relationship between the duration or frequency of seizures and the mean ipsilateral NAA/Cr ratio; however, the mean density of GFAP-immunopositive cells correlated with seizure frequency (p < 0.03).

Conclusions. The NAA/Cr ratio may not measure the full extent of hippocampal neuronal cell loss. The significant association of the NAA/Cr ratio with the GFAP immunoreactivity of most CA sectors indicates that the NAA/Cr ratio may provide a more accurate measurement of recent neuronal injury caused by epileptic activity. The coupling between neuronal impairment and astroglial GFAP expression may indicate the close association between neuronal and glial dysfunction in patients with epilepsy.