bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereotactic Brainstem Biopsy Is Indicated for the Diagnosis of a Vast Array of Brainstem Pathology
Authors: Samadani Uzma , Judy Kevin D.
Published: January 2004

Background/Aims: A meta-analysis of thirteen studies performing stereotactic biopsy of brainstem lesions is combined with our recent series of 12 patients with brainstem lesions comparing MRI findings to biopsy histopathology to determine whether these lesions could have been diagnosed radiographically. Methods: 12 consecutive stereotactic biopsies and literature analysis were performed to analyze clinical, radiographic and histopathologic data. Results: Stereotactic biopsy of lesions in the brainstem was in 96% diagnostic. There was one mortality (3% of cases) and 4% morbidity associated with the procedure. Pathology showed that half of the adult brainstem intrinsic lesions were gliomas, 10% were metastases, and the remainder were hematomas, vascular malformations, lymphomas, demyelination, cysts, radiation necrosis, abscesses, vasculitis, infarcts, leukemia, cryptococcus, or granulomas. Conclusions: Empiric treatment of adult brainstem lesions is not prudent because there is a wide spectrum of diverse pathology in this location. Stereotactic biopsy is a safe and effective method for determining histopathology.
Permanent Iodine-125 Interstitial Radiation Therapy in the Treatment of Non-Glioblastoma multiforme High-Grade Gliomas
Authors: Zamorano Lucia , Li Qinghang , Tekyi-Mensah Samuel , Gaspar Laurie , Fontanesi James , Levin Kenneth
Published: January 2004

Background: This study evaluates prognostic factors influencing survival outcomes for 60 patients with permanent iodine-125 implants in the primary treatment of non-glioblastoma multiforme (GBM) high-grade gliomas. Methods: Stereotactic treatment planning aimed to encompass the contrast-enhancing rim of the tumor visualized by CT, with an initial dose rate of 0.05 Gy/h with 125I, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Survival was evaluated using the Kaplan-Meier method for univariate analysis and the Cox regressional method for multivariate analysis. In addition to the implant, 34 patients received external radiation therapy (5,000–6,000 cGy) before the implant; 13 patients were implanted without additional external beam radiation, and 13 patients underwent external radiation therapy before implant placement. Results: With a mean follow-up of 77.6 months (range 3.5–164 months), 1-, 3-, 5- and 10-year survival were 86.7% (±0.05%), 60% (±0.07%), 50% (±0.07%) and 45.7% (±0.7%), respectively. The median survival time was 57 months. Second surgery was performed following the implant in 19 patients. Findings were tumor recurrence in 11 patients (22.5%), radiation necrosis in 7 patients (14.3%) and brain abscess in 1 patient (2%). Age, sex, tumor location, side of brain, tumor volume, Karnofsky score and neurological status were correlated with survival outcome. Favorable prognostic factors were age younger than 45 years, superficial tumor location and preoperative Karnofsky score greater than 70. RPA classification was used to define this group of patients. In RPA classes I and II (n = 43), 1-year survival was 93%, while 3-, 5- and 10-year survival was 67.4, 60.5 and 55.5%, respectively, and median survival time was 91 months. In RPA class III (n = 7), 1-year survival was 71.4%, while 3- and 5-year survival was 42.9 and 28.6%, respectively, and median survival time was 47 months. In RPA class IV (n = 10), 1-year survival was 60%, while 3-, 5- and 10-year survival was 50, 22.2 and 11.1%, respectively, and median survival time was 37 months. Conclusion: Brachytherapy with permanent implant of 125I appears promising in the treatment of primary non-GBM malignant gliomas. It improved survival time and reduced the incidence of complications and provided good quality of life. In order to further confirm these results, multicenter randomized prospective studies are needed. RPA analysis is a valid tool to define prognostically distinct survival groups. In this study, 2-year survival and median survival time were improved in all prognostic classes. This would suggest that selection bias alone does not account for the survival benefit seen with 125I implants. Further randomized studies with effective stratification are needed.
Posterior Fossa Metastases: Aggressive Treatment Improves Survival
Authors: Kanner Andrew A. , Suh John H. , Siomin Vitaly E. , Lee Shih-Yuan , Barnett Gene H. , Vogelbaum Michael A.
Published: January 2004

Background: Brain metastases are a leading cause of mortality and morbidity in patients with malignancies. Infratentorial location has been considered a negative prognostic factor. Methods: This retrospective study evaluated patients with cerebellar metastasis. Statistical analysis assessed age, extracranial disease, performance status and treatment. Patients were categorized by Radiation Therapy Oncology Group recursive partitioning analysis (RPA). Treatment included surgery, stereotactic radiosurgery (SRS) and whole brain radiotherapy (WBRT) alone or in combination. Results: Of 93 patients, the median survival was 12.9 months for RPA class I, 11 months for class II and 8 months for class III. On multivariate analysis, RPA class was an important predictor for overall survival. However, SRS with WBRT or surgery with WBRT or a combination of SRS, surgery and WBRT, was more favorable than surgery or SRS alone within RPA class II patients. Conclusions: Survival of patients with cerebellar brain metastasis is comparable to that of patients with supratentorial brain metastasis using RPA classification. Aggressive multimodality therapy has a favorable impact on survival.
From Letterbox to Keyhole Approach for Resecting Intracranial Lesions
Authors: Eljamel M. Sam , Hofer Monika
Published: January 2004

Background: Computer-assisted neurosurgery systems (CANS) have the ability to translate preoperative image data sets directly to the operating field and were thought to be very useful in neurosurgery. However, key questions regarding their use remain only partially addressed. Methods: To answer the doubts of the skeptics, we set up a registry of all CANS and any non-CANS procedures in our institution. The results of 354 procedures are presented in this paper. Results: CANS was used in 254 procedures, with a mean accuracy of 1.9 mm and a failure rate of 2.8%. Over time, the accuracy improved to 1.6 mm and failures were abolished. The CANS was most useful in anterior skull approaches and took less time in the operating room, and the patients were discharged earlier than those who underwent non-CANS procedures. Conclusion: We feel that the introduction of CANS has changed our practice for the better, with significant benefits to patients, surgeons and the hospital at large, and we recommend its usage as a standard of care.
Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia
Authors: Brisman Ronald
Published: January 2004

Background: Although gamma knife radiosurgery (GKRS) has been shown to be safe and effective for the treatment of trigeminal neuralgia (TN), there are few studies that report the results of a second GKRS. Method: Between May 22, 1998 and April 1, 2003, we treated 335 primary TN patients with GKRS. All received a maximum dose of 75 Gy to the cisternal trigeminal nerve. 45 patients with recurrent or persistent TN were treated with a maximum dose of 40 Gy at a second GKRS and were available for at least 6 months of follow-up. Results: Final pain relief (mean of 15 months after second GKRS) was 50% or greater in 28 of the 45 patients (62.2%). Patients who had no neurosurgical procedure prior to their first GKRS were more likely to have pain relief of 50% or greater following the second GKRS (p = 0.042). Significant new dysesthesias (score greater than 5 on a scale of 0–10) developed in 2 patients (4.4%). Conclusion: Repeat GKRS has a good chance of relieving TN pain without complications and is more likely to relieve pain in those who did not have any procedure prior to their first GKRS.
Long-Term Outcome of Spinal Cord Stimulation and Hardware Complications
Authors: Quigley D. Gavin , Arnold Jonathan , Eldridge Paul R. , Cameron Heather , McIvor Kate , Miles John B. , Varma T.R.K.
Published: January 2004

Spinal cord stimulation (SCS) is a treatment modality for medically intractable chronic pain. This study reports an 11-year experience with SCS assessing long-term pain relief and specifically evaluating complications and revisions. It took the form of a retrospective review of medical/surgical records with a postal questionnaire. The subjects were 102 patients with medically intractable chronic pain who underwent SCS implantation between 1989 and 2000. There were 64 revision operations carried out on 35 patients. These comprised electrode replacement/repositioning (29), generator replacement (23), cable failure (3) and implant removal (5). Five (4.9%) implants became infected and 2 required removal. Clinician-reported pain relief was substantial in 69 (68%) patients. This study adds to the weight of evidence that patients undergoing SCS derive significant benefits in terms of pain relief. However, revision rates remain high due to technical and biological factors.
Microvascular Decompression for Trigeminal Neuralgia in Patients with Multiple Sclerosis
Authors: Eldridge P.R. , Sinha A.K. , Javadpour M. , Littlechild P. , Varma T.R.K.
Published: January 2004

Aims: To assess whether microvascular decompression (MVD) is a safe and efficacious treatment for patients with trigeminal neuralgia (TGN) and multiple sclerosis (MS). Methods: Case records were reviewed of all patients with TGN and MS who underwent posterior fossa exploration with a view to MVD between 1993 and 2001. In all patients, magnetic resonance tomoangiography (MRTA) demonstrated vascular compression. Results: Nine patients were included in the study. Seven patients underwent MVD alone; in 2 patients a partial sensory rhizotomy of the trigeminal nerve was added to the decompression. All patients had excellent initial pain relief. Recurrence of neuralgia was noted in 5 patients after MVD and in 1 of the 2 patients after partial sensory rhizotomy. Long-term pain relief was obtained in 1 patient who underwent a redo MVD after postoperative MRTA scans demonstrated recurrent vascular compression of the root entry zone (REZ). Thus only 4 out of 9 patients maintained pain relief. In addition, 3 patients experienced transient worsening of their MS. Conclusions: Although MVD provides good initial pain relief, the recurrence rate is much higher than that obtained in ‘idiopathic’ TGN. Although all procedures for the treatment of TGN are worse than those for idiopathic TGN, it is concluded that because of the high recurrence rate together with the morbidity associated with the procedure MVD should not be offered to patients with TGN and MS.
Role of Pituitary Radiosurgery for the Management of Intractable Pain and Potential Future Applications
Authors: Hayashi Motohiro , Taira Takaomi , Chernov Mikhail , Izawa Masahiro , Liscak Roman , Yu Chung Ping , Ho Robert T.K. , Katayama Yoko , Kouyama Nobuo , Kawakami Yoriko , Hori Tomokatsu , Takakura Kintomo
Published: January 2004

Rationale: Two or three decades ago, cancer pain was treated by surgical/chemical hypophysectomy. In one report, the control of central pain (thalamic pain syndrome) was also approached with chemical hypophysectomy. Although in most of the patients these treatments resulted in a decrease in severe pain, concomitantly severe adverse effects (panhypopituitarism, diabetes insipidus and visual dysfunction) occurred in most patients. This historical evidence prompted us to perform Gamma Knife surgery (GKS) for this kind of intractable severe pain using a high irradiation dose to the pituitary stalk/gland. In the majority of patients, marked pain relief was achieved, surprisingly without any of the complications mentioned above. Materials and Methods: A prospective multicenter study was conducted to evaluate the efficacy and safety in patients treated in Prague, Hong Kong and Tokyo. Indications of this treatment were: (1) failure of other effective treatment approaches prior to GKS, (2) good general patient condition (Karnofsky performance status >40%), (3) response to morphine for pain control (cancer pain), and (4) no previous radiotherapy of brain metastases (GKS/conventional radiotherapy). Eight patients with severe cancer pain due to bone metastasis and 12 patients with post-stroke thalamic pain syndrome were treated with GKS. The target was the border between the pituitary stalk and gland. Maximum dose was 160 Gy for cancer pain and 140 Gy for central pain. Follow-up included 6 patients (>1 month) with cancer pain and 8 patients (> 6 months) with thalamic pain syndrome. Results: All patients (6/6) with cancer pain experienced significant pain reduction, and 87.5% (7/8) of the patients with thalamic pain had initially significant pain reduction. In some patients, pain reduction was delayed for several hours. Pain relief was noted within 7 days (median 2 days). No recurrence was observed in the patients with cancer pain. However, in 71.4% (5/7) of the patients with thalamic pain syndrome, disease recurred during the 6-month follow-up. Up to now, other complications have not been observed. Conclusion: Our clinical study protocol is only preliminary. Further clinical results on the management of thalamic pain are required to develop this treatment protocol. However, efficacy and safety have been shown in all our cases. In our opinion, this treatment has a potential to control severe pain, and GKS will play an important role in the management of intractable pain.
Evaluation of CyberKnife Frameless Real-Time Image-Guided Stereotactic Radiosurgery for Spinal Lesions
Authors: Gerszten Peter C. , Ozhasoglu Cihat , Burton Steven A. , Vogel William , Atkins Barbara , Kalnicki Shalom , Welch William C.
Published: January 2004

Background: This study evaluated the CyberKnife frameless image-guided radiosurgery system for the treatment of spinal lesions. Methods: This system utilizes the coupling of an orthogonal pair of X-ray cameras to a dynamically manipulated robot-mounted linear accelerator that guides the therapy beam to the intended target without the use of frame-based fixation. Cervical spine lesions are located and tracked relative to skull bony landmarks; lower spinal lesions are tracked relative to fiducial markers. 125 spinal lesions in 115 consecutive patients were treated with a single-fraction radiosurgery technique. Results: Tumor volume ranged from 0.3 to 232 ml (mean 27.8 ml). Tumor radiation dose was maintained at 12–20 Gy to the 80% isodose line (mean 14 Gy); the spinal cord or canal volume receiving greater than 8 Gy ranged from 0.0 to 1.7 ml (mean 0.2 ml). No acute radiation toxicity or new neurological deficits occurred during the follow-up period (3–24 months). Conclusions: The CyberKnife system was found to be feasible, safe and effective. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and good response.
Bilateral Anterior Capsulotomy for Refractory Obsessive-Compulsive Disorders
Authors: Oliver Bartolomé , Gascón Josep , Aparicio Alberto , Ayats Emilio , Rodriguez Rodrigo , Maestro de León Juan Luis , García-Bach Marcel , Soler Pere Anton
Published: January 2004

A prospective study on the effects of bilateral anterior capsulotomy in patients with refractory obsessive-compulsive disorder (OCD) is presented. A total of 18 procedures were performed in 15 patients. The mean duration of the OCDs was 18.1 ± 5.6 years (range 11–26 years). The mean total Yale-Brown Scale (Y-BOCS) score was 29.67 and mean Global Assessment of Functioning was 43.61. The results throughout the follow-up period remained the same as at 1 month postoperatively. The observed mean recovery on the Y-BOCS was 33.2% (p = 0.017). 52.9% of the patients showed a 33% recovery, 29.4% of the cases showed a 50% recovery and 17% showed a 66% recovery. Global Assessment of Functioning recovered by 19% (p = 0.111). No cognitive deficit was disclosed by neuropsychological screening tests. Complications were observed in 3 cases, 1 with transitory hallucinations, 1 with a single epileptic seizure and 1 case who developed a progressive behavior disorder that became permanent. We conclude that bilateral anterior capsulotomy is a safe and effective procedure.
Clinical Study for Alleviating Opiate Drug Psychological Dependence by a Method of Ablating the Nucleus accumbens with Stereotactic Surgery
Authors: Gao Guodong , Wang Xuelian , He Shiming , Li Weixin , Wang Qingfeng , Liang Qinchuan , Zhao Yaqun , Hou Fang , Chen Ling , Li Aining
Published: January 2004

The aim of this study was to explore a new way of treating drug addiction by ablating the nucleus accumbens (NAC), which has a close relationship with drug-induced psychological dependence, using stereotactic surgery, blocking the mesocorticolimbic dopamine circuit, alleviating craving for drugs and lowering the relapse rate after detoxification. On the basis of animal experiments, stereotactic surgery was performed in 28 patients by making a lesion in the NAC bilaterally to treat opiate drug dependence. Indications, the criterion of therapeutic effect, treatment process and the therapeutic and safety evaluation index of the surgery were formulated particularly. The mean follow-up period was 15 months. Relapse has not occurred in 11 cases up till now. Drug-free time in these patients has been more than half a year in 4 cases (more than a year in 3 cases), and less than half a year in 7 cases. Relapse occurred in 15 cases after surgery. Drug-free time in these patients was more than half a year in 3 cases, between 1 month and half a year in 10 cases and less than 1 month in 2 cases. The therapeutic effect was excellent in 7 cases (26.9%), good in 10 cases (38.5%) and poor in 2 cases (7.7%). Another 7 cases were still under investigation at the time of writing. Relapse rates after surgery were 7.7, 38.5 and 57.5% within 1 month, between 1 month and half a year and after more than half a year, respectively. There were no common complications of surgery such as intracranial hematoma or infection in these patients after operation. Character type was changed slightly in 2 cases, and 4 cases suffered temporary memory loss, which did not affect their daily lives and learning function. They all recovered within 1 month. There were different degrees of effectiveness of treating drug addicts’ psychological dependence by making lesions in the NAC bilaterally with stereotactic surgery. No particular complications occurred. The operation is safe and feasible. The mean follow-up time in this study was 15 months. The effectiveness was satisfactory. The relapse rate of drug addicts after detoxification was clearly reduced.
Cyberknife Radiosurgery for Trigeminal Neuralgia
Authors: Romanelli Pantaleo , Heit Gary , Chang Steven D. , Martin Dave , Pham Christopher , Adler John
Published: January 2004

Background: We present preliminary results using Cyberknife radiosurgery as a noninvasive treatment for trigeminal neuralgia (TN). Methods: Ten patients with medically refractory TN who were deemed unsuitable for conventional surgery underwent Cyberknife radiosurgery using CT cisternography for localization. Results: Pain relief was achieved in 7 patients, in 5 of them within 24–72 h after irradiation. Conclusion: Cyberknife radiosurgery can achieve early-onset pain relief in a subset of TN patients. Improvements using this technique include the absence of a stereotactic ring, potentially improved targeting accuracy produced by CT cisternography and improved dose homogeneity.
Use of a Multichannel Auditory Brainstem Implant for Neurofibromatosis Type 2
Authors: Schwartz Marc S. , Otto Steven R. , Brackmann Derald E. , Hitselberger William E. , Shannon Robert V.
Published: January 2004

Neurofibromatosis type 2 (NF 2) typically results in deafness due to disruption of the cochlear nerves, making peripheral devices such as cochlear implants ineffective. Auditory brainstem implants (ABIs), for direct electrical stimulation of the cochlear nucleus, have been used to provide auditory stimulation in this group of patients. Currently, 141 patients have been implanted in our institution, most recently using an advanced multichannel device. We report results of a recent series of 86 patients who received ABIs. Of this group, 60 had successful implantation, recovered from surgery, responded successfully to stimulation and underwent a full course of device programming and audiologic testing. This group had significant improvement in scores on several audiologic tests compared to baseline. When used to augment lip reading, improvement was also seen. The degree of improvement varied considerably among patients. ABI is a useful device for deaf patients with NF 2. As measured by audiologic testing, many patients receive substantial benefit with regard to sound and speech comprehension.
Vagus Nerve Stimulation Therapy for Patients with Persistent Seizures after Epilepsy Surgery
Authors: Amar Arun Paul , Apuzzo Michael L.J.
Published: January 2004

Background: This study reports the effectiveness of vagus nerve stimulation (VNS) among patients who failed cranial surgery for intractable epilepsy. Methods: Data were obtained from the Cyberonics VNS therapy patient outcome registry. The integrity of the systems for collecting and processing registry data was authenticated by an independent auditing agency. Results: Two nonconsecutive cohorts were compared: patients who had had prior cranial surgery (CS group, n = 921) and those who had not (non-CS group, n = 3,822). For the CS group, the median reduction in seizure frequency was 42.5% after 3 months of VNS therapy, 42.9% at 6 months, 45.7% at 12 months, 52.0% at 18 months and 50.5% at 24 months. For the non-CS group, analogous rates were 47.0, 52.9, 60.0, 62.7 and 66.7%, respectively. Conclusion: The effectiveness of VNS is maintained during prolonged stimulation. Patients who failed prior cranial surgery did not respond quite as favorably as all other patients receiving VNS therapy.
A 10-Year Experience with Magnetic Source Imaging in the Guidance of Epilepsy Surgery
Authors: Smith Joseph R. , King Don W. , Park Yong D. , Murro Anthony M. , Lee Gregory P. , Jenkins Patrick D.
Published: January 2004

Magnetic source imaging (MSI) of interictal epileptiform dipoles was studied in 100 epilepsy surgery candidates. Sixty underwent surgery. MSI epileptiform data were classified as focal, regional, multifocal, scattered or none. Resections of MSI epileptiform foci were classified as extensive (EXT) versus partial or none (P/N). MSI interictal epileptiform dipoles were found in 22 of 27 anterior temporal (ATL) cases, and in 31 of 33 extratemporal (XMT) cases. Of 10 EXT ATL cases, 5 (50%) were seizure free (SF). Of 12 P/N ATL cases, 7 (58%) were SF. Of 10 nonlesional EXT XMT resections, 8 (80%) were SF. Of 10 nonlesional P/N XMT resections, 1 (10%) was SF. Neither focality of MSI data or spatial agreement of electrographic and MSI data significantly affected outcomes.
Subtemporal Amygdalohippocampectomy Prevents Verbal Memory Impairment in the Language-Dominant Hemisphere
Authors: Hori Tomokatsu , Yamane Fumitaka , Ochiai Taku , Hayashi Motohiro , Taira Takaomi
Published: January 2004

Background: In this report, we show the operative and neuropsychological results for 20 patients with medically intractable nonlesional temporal lobe epilepsy treated surgically by subtemporal amygdalohippocampectomy whose mean postoperative follow-up period was more than 6 years. Methods: Pre- and postoperative Wechsler Adult Intelligence Scale-Revised (WAIS/-R) scores, including verbal intelligence quotient (VIQ), performance IQ (PIQ) and full-scale IQ (FIQ) scores, were determined in the 19 adults. The revised Wechsler Intelligent Scale for Children was used in a 9-year-old boy. The verbal paired associates learning test was performed pre- and postoperatively in 15 patients. These data were compared pre- and postoperatively in 10 patients in whom the language-dominant hemisphere side was operated on, and in 5 patients in whom the language-non-dominant side was operated on. Results: Seizure control was achieved in 80% of patients, with improvement into Engel categories I and II without definite permanent complications except for postoperative memory impairment in one patient. VIQ improved after 2 years, and PIQ and FIQ improved after both 2 months and 2 years postoperatively. Conclusion: There was no significant decline in the postoperative verbal memory scores in those patients whose medial temporal structure of the language-dominant side had been removed.
Peri-Insular Hemispherotomy: Potential Pitfalls and Avoidance of Complications
Authors: Daniel Roy Thomas , Villemure Jean Guy
Published: January 2004

Techniques for cerebral hemispherectomy have progressively evolved towards more disconnection and less excision over the last 50 years. Peri-insular hemispherotomy (PIH), as described by the senior author, has the maximal ratio of disconnection to excision among all procedures for hemispheric epilepsy. In this study, we focus on surgical complications and intraoperative anatomical observations during PIH over the last 10 years. Based on this experience, the procedure has undergone some modifications, which we detail herein.
Effect of High-Frequency Stimulation of the Subthalamic Nucleus on Subthalamic Neurons: An Intracellular Study
Authors: Lee Kendall H. , Roberts David W. , Kim Uhnoh
Published: January 2004

Background/Aims: The precise mechanism of action of deep brain stimulation in the subthalamic nucleus (STN) for the treatment of Parkinson’s disease and epilepsy is unknown. In the present study, the intracellular effects on STN neurons following high-frequency stimulation (HFS) of STN were examined to test the hypothesis that HFS results in either an increase or a decrease in neuronal action potential generation. Methods: Intracellular electrophysiological recordings were made in the rat STN neurons in in vitro slice preparations. A concentric bipolar stimulating electrode was placed in the STN, and electrical stimulation (duration, 100–2000 ms; amplitude, 10–500 µA, and frequency, 10–200 Hz) was delivered while simultaneously recording intracellularly from a STN neuron using a sharp electrode. Results: HFS of STN resulted in the generation of excitatory postsynaptic potentials and an increase in action potential firing during the stimulation period followed by a period of poststimulation inhibition of firing in STN neurons. The degree of increase in action potentials from HFS was critically dependent on the frequency of electrical stimulation, i.e. at approximately 100–140 Hz, maximal increase was obtained, but at 200 Hz, the activity was blocked. Interestingly, the duration of poststimulation inhibition of firing was dependent on the duration of stimulation, i.e. the longer the HFS, the longer the inhibition. Conclusions: These results suggest that the mechanism of action of deep brain stimulation involves initial excitation followed by later inhibition of STN neurons at a cellular level rather than primary inhibition, as previously hypothesized.
Subthalamic Nucleus Stimulation in Parkinson’s Disease: Correlation of Active Electrode Contacts with Intraoperative Microrecordings
Authors: Hamel W. , Fietzek U. , Morsnowski A. , Schrader B. , Weinert D. , Müller D. , Deuschl G. , Mehdorn H.M.
Published: January 2004

Background/Aims: The most effective site for subthalamic nucleus (STN) stimulation has remained unclear. The position of active contacts relative to the dorsal margin of the STN was determined. Methods: Electrodes (n = 49) were implanted following STN mapping by microrecording and microstimulation along five tracks (n = 25 patients). The stereotactic position of active contacts was determined and correlated with microrecordings using an algorithm for direct three-dimensional comparisons (n = 37). Results: Most active contacts were detected within ±1.0 mm from the dorsal margin of the STN as defined by microrecording (32.4%) or farther dorsal in the subthalamic area (37.8%), and only 29.7% were localized to the STN proper. This was consistent with the average stereotactic coordinates of the active contacts in these three groups. Conclusion: Our data suggest that the dorsal border area of the STN is the most effective target. Besides the dorsolateral STN (sensorimotor part) this may include projections from/to STN, the zona incerta, and pallidofugal projections in the fields of Forel.
Effect of Motor Improvement on Quality of Life following Subthalamic Stimulation Is Mediated by Changes in Depressive Symptomatology
Authors: Tröster Alexander I. , Fields Julie A. , Wilkinson Steven , Pahwa Rajesh , Koller William C. , Lyons Kelly E.
Published: January 2004

Background/Aims: Subthalamic deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) improves motor symptoms and quality of life (QOL). Because depression is a potent correlate of QOL, and STN-DBS may be associated with changes in mood, this study sought to determine whether QOL improvement is a direct or indirect consequence of motor improvement. Methods: 26 patients with PD, free of dementia and major depression, who consecutively underwent bilateral, microelectrode-guided STN-DBS, underwent preoperative and 3-month postoperative neuropsychological evaluation, including measures of QOL (PD Questionnaire –39) and depressive symptoms (Beck Depression Inventory). Results: Motor score in the Unified Parkinson’s Disease Rating Scale (UPDRS Part III) improved significantly with STN-DBS relative to preoperative ‘on’ and ‘off’ scores, as did QOL and depressive symptoms. Extent of QOL improvement tended to be associated with improvement in motor score from presurgical on to postsurgical on stimulation and on medication state. QOL improvement was significantly related to amelioration of depressive symptoms. Partial correlations revealed that the association between QOL improvement and depression remained significant when influence of motor improvement on QOL and depression was controlled for. The motor-QOL association was no longer significant when effects of depression were controlled for. Conclusions: Significant QOL improvements after STN-DBS are associated with improved motor ‘on’ state and depressive symptoms. The influence of motor improvement on QOL may be largely indirect by reducing depression.
Thalamic Stimulation in Patients with Multiple Sclerosis: Long-Term Follow-Up
Authors: Schulder Michael , Sernas Thomas J. , Karimi Reza
Published: January 2004

Background: We assessed the long-term effect of deep brain stimulation (DBS) in patients with multiple sclerosis (MS). Methods: Nine patients with MS-induced tremor underwent placement of a DBS electrode in the thalamus. All patients were referred from the tertiary MS center at the New Jersey Medical School. Intraoperative macrostimulation was performed under local anesthesia before permanent implantation. Preoperative and postoperative evaluation included magnetic resonance imaging (MRI), the Extended Disability Status Scale (EDSS), the Bain-Finchley tremor scale, neuropsychological testing and patient assessment of the benefit from surgery. Results: There were no surgical complications. Follow-up ranged from 9 to 48 months (mean 32 months). EDSS scores averaged 7.2 before surgery, 6.8 at 6 months after surgery and 7.8 at late follow-up. Tremor scores averaged 5.4 before surgery, 1.7 at 6 months after surgery and 2.1 at late follow-up. Four patients who had significant tremor reduction at 6 months had severe MS progression afterwards, and one was lost to late follow-up. Another patient, in whom excellent tremor control was obtained, developed increasing stimulation-induced fatigue, and the implant was removed at his request. The 3 other patients have maintained a worthwhile benefit from DBS. MRI scans did not show any new MS plaques in relation to the electrode, although imaging was consistent with disease progression in all patients. Neuropsychological testing showed a mild to moderate decline in cognitive function consistent with disease progression. Conclusions: Chronic thalamic stimulation decreases tremor in patients with MS. However, this improvement does not correlate with improvement in objective measures of function. Any actual benefit may be limited in most patients by the progression of underlying disease. DBS for relief of tremor in patients with MS should be considered only in carefully selected patients with relatively stable disease, in whom upper extremity tremor is a disabling symptom.
Longevity of Batteries in Internal Pulse Generators Used for Deep Brain Stimulation
Authors: Bin-Mahfoodh Mohammed , Hamani Clement , Sime Elspeth , Lozano Andres M.
Published: January 2004

The longevity of batteries in internal pulse generators (IPGs) used clinically for deep brain stimulation is not known. We conducted a study to assess the life span of these batteries. From 1993 to 2000, 163 single-channel batteries were surgically implanted in our institution. The electrical settings utilized in patients who had battery failures were assessed and the total electrical energy delivered (TEED) was calculated and correlated with battery longevity. Fourteen IPGs had battery failure requiring replacement. The median life span of the batteries was 45 months. Batteries with high energy consumption as assessed by TEED had a reduced life span (r = –0.82, p ≤ 0.001). Patients with essential tremor who required battery replacement needed higher settings to control their symptoms and therefore presented a shorter battery life when compared to patients with Parkinson’s disease. In our series of patients who needed battery replacement, battery longevity varied with stimulation parameters but was longer than expected from the manufacturer’s specifications.
Variability in Position of the Subthalamic Nucleus Targeted by Magnetic Resonance Imaging and Microelectrode Recordings as Compared to Atlas Co-Ordinates
Authors: Littlechild P. , Varma T.R.K. , Eldridge P.R. , Fox S. , Forster A. , Fletcher N. , Steiger M. , Byrne P. , Tyler K. , Flintham S.
Published: January 2004

Background: Traditional methods for localisation of target nuclei for deep brain stimulation (DBS) have used brain atlas co-ordinates for initial targeting. It is now possible to visualise the subthalamic nucleus (STN) on magnetic resonance imaging (MRI) and determine the individual variability of its position. Methods: The present study was performed in patients undergoing STN DBS for Parkinson’s disease. The STN was directly targeted from axially obtained MRI and verified with microelectrode recordings. Postoperatively, the most effective contact was identified for each patient, and its position was calculated. Results: Fifty electrodes were inserted in 25 patients. The target position varied considerably in relation to the mid-commissural point. The mean effective contact position lies just dorsal to the location of the STN in a standard brain atlas. Conclusion: The STN varies in position, and can be accurately targeted from MRI alone.
Stereotactic Ventrooralis Thalamotomy for Task-Specific Focal Hand Dystonia (Writer’s Cramp)
Authors: Taira Takaomi , Hori Tomokatsu
Published: January 2004

Background: Writer’s cramp is a type of focal dystonia due to dysfunction of the pallido-thalamo-cortical circuit. The symptom is refractory to most conservative treatment, though botulinum toxin injection is generally used for symptomatic relief. As a surgical treatment of dystonia, we performed stereotactic nucleus ventrooralis (Vo) thalamotomy for dystonic cramp of the hand. Methods: Twelve patients (5 men, 3 women; age 26–40 years, mean 32.1 years) with medically intractable task-specific focal dystonia of the hand underwent Vo thalamotomy. The stereotactic target was chosen at the junction of the anterior and posterior Vo nuclei. Results: The mean duration of the symptom ranged from 3 to 6 years (mean 4.5 years.) All patients had complained of difficulty in writing. Seven patients were professionals, such as a comic artist, guitarist and barber, and, because of the dystonic symptoms occurring during their work, they had stopped pursuing their profession. All patients showed immediate postoperative disappearance of dystonic symptoms, and the effect was sustained during the follow-up period (3–33 months, mean 13.1 months), except in one case. Two patients showed partial recurrence of the symptom and underwent second thalamotomy 5 months after the initial surgery with satisfactory results. The score on the writer’s cramp rating scale decreased significantly (p < 0.001) after Vo thalamotomy. There were no permanent operative complications. There was no mortality or permanent morbidity. Conclusion: Although a longer follow-up is needed, stereotactic Vo thalamotomy is a useful and safe therapeutic option for writer’s cramp.
A Novel Denervation Procedure for Idiopathic Cervical Dystonia
Authors: Taira Takaomi , Hori Tomokatsu
Published: January 2004

Background: For idiopathic cervical dystonia, the treatment of choice is botulinum toxin injection or surgical denervation. There are two major procedures of surgical denervation: intradural ventral rhizotomy and extradural peripheral neurotomy (Bertrand procedure). The Bertrand procedure is always accompanied by popstoperative sensory loss in the C2 region. Methods: The authors have modified these procedures to minimize the complications. Our method is unilateral intradural ventral rhizotomy of C1 and C2, extradural denervation of the C3–C6 posterior rami and contralateral peripheral sectioning of the branches of the accessory nerve to the sternocleidomastoid muscle. Forty-four patients underwent this modified operation (‘Taira’s’ method: group A) and the results were compared with those in a matched control group of 38 patients who underwent the traditional Bertrand’s procedure (Bertrand’s method: group B). Results: Three patients in group A showed a sensory deficit in the C2 area, while all of the patients in group B had C2 sensory disturbance. Pre- and postoperative rating scores did not differ between the two groups. The intraoperative blood loss was significantly smaller in group A. Conclusion: Compared with the traditional Bertrand’s operation, our procedure carries a much lower incidence of complications and a significant decrease of intraoperative blood loss.
A Quick and Universal Method for Stereotactic Visualization of the Subthalamic Nucleus before and after Implantation of Deep Brain Stimulation Electrodes
Authors: Hariz Marwan I. , Krack Paul , Melvill Roger , Jorgensen Jan V. , Hamel Wolfgang , Hirabayashi Hidehiro , Lenders Mathieu , Wesslen Nils , Tengvar Magnus , Yousry Tarek A.
Published: January 2004

For deep brain stimulation (DBS) of the subthalamic nucleus (STN), it would be an advantage if the STN could be visualized with fast acquisition of MR images, allowing direct and individual targeting. We present a protocol for T2-weighted, nonvolumetric fast-acquisition MRI, implemented at 8 centers in 6 countries. Acquisition time varied between 3 min 5 s and 7 min 48 s according to the center, and imaging often provided visualization of the STN on axial and coronal scans. Postoperatively, the same imaging protocol permitted visualization of the target area and DBS electrodes with minimum artifacts. This imaging technique may contribute to a decrease in the number of electrode passes at surgery.
The NASA Smart Probe Project for Real-Time Multiple Microsensor Tissue Recognition
Authors: Andrews Russell J. , Mah Robert W.
Published: January 2004

Background: Remote surgery requires automated sensors, effectors and sensor-effector communication. The NASA Smart Probe Project has focused on the sensor aspect. Methods: The NASA Smart Probe uses neural networks and data from multiple microsensors for a unique tissue signature in real time. Animal and human trials use several probe configurations: (1) 8-microsensor probe (2.5 mm in diameter) for rodent studies (normal and subcutaneous mammary tumor tissues), and (2) 21-gauge needle probe with 3 spectroscopic fibers and an impedance microelectrode for breast cancer diagnosis in humans. Multisensor data are collected in real time (update 100 times/s) using PCs. Results: Human data (collected by NASA licensee BioLuminate) from 15 women undergoing breast biopsy distinguished normal tissue from both benign tumors and breast carcinoma. Tumor margins and necrosis are rapidly detected. Conclusion: Real-time tissue identification is achievable. Potential applications, including probes incorporating nanoelectrode arrays, are presented.
Functional Magnetic Resonance Imaging in a Low-Field Intraoperative Scanner
Authors: Schulder Michael , Azmi Hooman , Biswal Bharat
Published: January 2004

Background: Functional magnetic resonance imaging (fMRI) has been used for preoperative planning and intraoperative surgical navigation. However, most experience to date has been with preoperative images acquired on high-field echoplanar MRI units. We explored the feasibility of acquiring fMRI of the motor cortex with a dedicated low-field intraoperative MRI (iMRI). Methods: Five healthy volunteers were scanned with the 0.12-tesla PoleStar N-10 iMRI (Odin Medical Technologies, Israel). A finger-tapping motor paradigm was performed with sequential scans, acquired alternately at rest and during activity. In addition, scans were obtained during breath holding alternating with normal breathing. The same paradigms were repeated using a 3-tesla MRI (Siemens Corp., Allandale, N.J., USA). Statistical analysis was performed offline using cross-correlation and cluster techniques. Data were resampled using the ‘jackknife’ process. The location, number of activated voxels and degrees of statistical significance between the two scanners were compared. Results: With both the 0.12- and 3-tesla imagers, motor cortex activation was seen in all subjects to a significance of p < 0.02 or greater. No clustered pixels were seen outside the sensorimotor cortex. The resampled correlation coefficients were normally distributed, with a mean of 0.56 for both the 0.12- and 3-tesla scanners (standard deviations 0.11 and 0.08, respectively). The breath holding paradigm confirmed that the expected diffuse activation was seen on 0.12- and 3-tesla scans. Conclusions: Accurate fMRI with a low-field iMRI is feasible. Such data could be acquired immediately before or even during surgery. This would increase the utility of iMRI and allow for updated intraoperative functional imaging, free of the limitations of brain shift.
Use of the NeuroMate Stereotactic Robot in a Frameless Mode for Movement Disorder Surgery
Authors: Varma T.R.K. , Eldridge P.R. , Forster A. , Fox S. , Fletcher N. , Steiger M. , Littlechild P. , Byrne P. , Sinnott A. , Tyler K. , Flintham S.
Published: January 2004

Background/Aims: To evaluate the use of the NeuroMate stereotactic robot with a novel ultrasound registration system for movement disorder surgery (MDS). Methods: Using the robot in a frameless mode, 51 patients underwent MDS. Surgical planning was carried out using MRI data obtained more than 24 h before surgery. Results: 37 out of 50 targets in the subthalamic nucleus were satisfactorily identified with a single microelectrode trajectory and the final electrode positions were at a mean distance of 1.7 mm from the calculated target. There was a significant improvement in motor scores of the Unified Parkinson’s Disease Rating Scale III (off medication) at 6 (43%) and 18 months (51.7%) compared to pre-operative scores (p < 0.05). Conclusions: The frameless robot using only MRI data can be used for MDS. The temporal separation of imaging from the surgical procedure provides additional time for detailed image analysis and planning.
Integration of Neurosurgical Image Guidance and an Intraoperative Magnetic Resonance Scanner
Authors: Maciunas Robert J. , Dean David , Lewin Jonathan , Selman Warren R. , Ratcheson Robert A.
Published: January 2004

Background: Intraoperative magnetic resonance (MR) imaging has been employed as an alternative to image guidance using preoperative images. We integrated both systems to evaluate their clinical use. Methods: The BrainLAB VectorVisionTM system was integrated in an intraoperative Siemens Open Viva 0.2-tesla MR system. Clinical experience was assessed. Results: Patterns of intraoperative imaging emerged, and benefit was seen in registering preoperative and intraoperative images. Conclusions: This integrated system has clinically observed effects on imaging, navigation, and surgery.
Proteome Analysis for the Identification of Tumor-Associated Biomarkers in Gastrointestinal Cancer
Authors: Fels Lüder M. , Buschmann Thomas , Meuer Jörn , Reymond Marc A. , Lamer Stephanie , Röcken Christoph , Ebert Matthias P.A.
Published: January 2004

Gastrointestinal cancers are usually diagnosed at advanced stages, making a curative treatment difficult. Biomarkers can help to overcome this problem by allowing earlier diagnosis, and thus better therapy. Proteomics tools are novel technologies to identify such biomarkers. This review summarizes advances in biomarker detection using two-dimensional gel electrophoresis (2D-PAGE), chromatography and mass spectrometry technologies. 2D-PAGE combined with mass spectrometry has led to the identification of several differentially expressed proteins in cancer tissue. However, for serum analysis, 2D-PAGE has severe limitations. For serum-based cancer diagnosis, surface-enhanced laser desorption-ionization time-of-flight (SELDI-TOFTM) mass spectrometry is a promising new technology. The potential of proteins identified with this technology as novel cancer biomarkers still needs to be confirmed in clinical trials.
DNA Methylation Markers in Patients with Gastrointestinal Cancers
Authors: Lofton-Day Catherine , Lesche Ralf
Published: January 2004

DNA methylation, the modification of a cytosine nucleotide immediately preceding a guanine base in a stretch of DNA, is rapidly gaining strength in the diagnostic field as a powerful tool to be utilized for the discrimination of neoplastic tissue from its healthy counterpart. This epigenetic modification occurs often in the promoter region of genes and is associated with transcriptional silencing of tumor suppressors or other genes important for normal cellular function. These changes have been found to occur at very early stages in the progression of healthy to malignant phenotype in many cancer types. We are taking a targeted approach to finding methylation-based markers that can be used not only for the early detection of cancer but also for determining risk, monitoring patient response to therapy and even determining the degree of aggressiveness of a tumor. In this paper, we review the progress in our understanding of methylation in gastrointestinal tumors, the potential clinical applications of methylation-based markers and our process for the discovery and validation of highly specific and sensitive markers for the use in these applications.
Application of DNA Array Analyses in the Management of Gastrointestinal Cancer Patients
Authors: Buchholz Malte , Gress Thomas M.
Published: January 2004

Cancer is a polygenic disease arising from the accumulation of multiple genetic and epigenetic defects in the affected cells. For the majority of cancers, including many malignancies of the gastrointestinal tract, our current means of diagnosis and treatment of the tumors are grossly insufficient. DNA arrays offer the possibility to monitor the expression levels of thousands of mRNA transcripts simultaneously in a single assay, making them ideal tools to study the complex network of transcriptional changes that are associated with the malignant transformation of normal cells. Expression profiling analyses are rapidly expanding our knowledge of tumor cell biology, laying the basis for the development of more sophisticated diagnostic procedures and more effective treatment modalities. This review will discuss current applications and future perspectives of DNA array technology in oncological research and tumor patient management.