bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-time control of a prosthetic hand using human electrocorticography signals
Authors: Yanagisawa Takufumi , Hirata Masayuki , Saitoh Youichi , Goto Tetsu , Kishima Haruhiko , Fukuma Ryohei , Yokoi Hiroshi , Kamitani Yukiyasu , Yoshimine Toshiki 
Published: February 2011

Object
A brain-machine interface (BMI) offers patients with severe motor disabilities greater independence by controlling external devices such as prosthetic arms. Among the available signal sources for the BMI, electrocorticography (ECoG) provides a clinically feasible signal with long-term stability and low clinical risk. Although ECoG signals have been used to infer arm movements, no study has examined its use to control a prosthetic arm in real time. The authors present an integrated BMI system for the control of a prosthetic hand using ECoG signals in a patient who had suffered a stroke. This system used the power modulations of the ECoG signal that are characteristic during movements of the patient's hand and enabled control of the prosthetic hand with movements that mimicked the patient's hand movements.

Methods
A poststroke patient with subdural electrodes placed over his sensorimotor cortex performed 3 types of simple hand movements following a sound cue (calibration period). Time-frequency analysis was performed with the ECoG signals to select 3 frequency bands (1–8, 25–40, and 80–150 Hz) that revealed characteristic power modulation during the movements. Using these selected features, 2 classifiers (decoders) were trained to predict the movement state—that is, whether the patient was moving his hand or not—and the movement type based on a linear support vector machine. The decoding accuracy was compared among the 3 frequency bands to identify the most informative features. With the trained decoders, novel ECoG signals were decoded online while the patient performed the same task without cues (free-run period). According to the results of the real-time decoding, the prosthetic hand mimicked the patient's hand movements.

Results
Offline cross-validation analysis of the ECoG data measured during the calibration period revealed that the state and movement type of the patient's hand were predicted with an accuracy of 79.6% (chance 50%) and 68.3% (chance 33.3%), respectively. Using the trained decoders, the onset of the hand movement was detected within 0.37 ± 0.29 seconds of the actual movement. At the detected onset timing, the type of movement was inferred with an accuracy of 69.2%. In the free-run period, the patient's hand movements were faithfully mimicked by the prosthetic hand in real time.

Conclusions
The present integrated BMI system successfully decoded the hand movements of a poststroke patient and controlled a prosthetic hand in real time. This success paves the way for the restoration of the patient's motor function using a prosthetic arm controlled by a BMI using ECoG signals.
Quality of life in patients with intracranial gliomas: the impact of modern image-guided surgery
Authors: Jakola Asgeir S. , Unsgård Geirmund , Solheim Ole 
Published: February 2011

Object
Outcome following brain tumor operations is often assessed by health professionals using various gross function scales. However, surprisingly little is known about how modern glioma surgery affects quality of life (QOL) as reported by the patients themselves. In the present study the authors aimed to assess changes in QOL after glioma surgery, to explore the relationship between QOL and traditional outcome parameters, and to examine possible predictors of change in QOL.

Methods
Eighty-eight patients with glioma were recruited from among those 16 years or older who had been admitted to the authors' department for brain tumor surgery in the period between January 2007 and December 2009. A 3D ultrasonography–based navigation system was utilized in nearly all operations and functional MR imaging data on eloquent lesions were incorporated into the neuronavigation system. Preoperative scores for QOL (EuroQol 5D [EQ-5D]) and functional status (Karnofsky Performance Scale [KPS]) were obtained. The EQ-5D and KPS scores were subsequently recorded 6 weeks postoperatively, as were responses to a structured interview about new deficits and possible complications.

Results
There was no change in the median EQ-5D indexes following surgery, 0.76 versus 0.75 (p = 0.419). The EQ-5D index value was significantly correlated with the KPS score (p < 0.001; rho = 0.769). The EQ-5D index values and KPS scores improved in 35.2% and 24.1% of cases, were equal in 20.5% and 47.2% of cases, and deteriorated in 44.3% and 28.7%, respectively. Thus, both improvement and deterioration were underestimated by the KPS score as compared with the patient-reported QOL assessment. New motor deficits (p = 0.003), new language deficits (p = 0.035), new unsteadiness and/or ataxia (p = 0.001), occipital lesions (p = 0.019), and no use of ultrasonography for resection control (p = 0.021) were independent predictors of worsening QOL in a multivariate model.

Conclusions
The surgical procedures per se may not significantly alter QOL in the average patient with glioma; however, new deficits have a major undesirable effect on QOL. It seems that the active use of intraoperative ultrasonography may be associated with a preservation of QOL. The EQ-5D seems like a good outcome measure with a strong correlation to traditional variables while offering a more detailed description of outcome.
The BION devices: injectable interfaces with peripheral nerves and muscles
Authors: Loeb Gerald E. , Richmond Frances J. R. , Baker Lucinda L. 
Published: February 2011

Object
The purpose of this study was to describe a novel technology for implantable neuromuscular stimulation to treat complications of paralysis and disuse atrophy, including shoulder subluxation, hand contractures, drop foot, and osteoarthritis. The authors review the results so far of several pilot clinical studies of these muscle stimulation devices.

Methods
Miniature wireless stimulators received power and individually addressed command signals from an external radiofrequency transmission coil. One or more implants were injected through a 12-gauge hypodermic insertion tool into muscles or adjacent to motor nerves, where they provided the means to activate the muscles in any desired pattern of intensity and frequency. Randomized controlled studies in small numbers of patients are underway to identify efficacy, acceptability, best methods of practice, and any design changes that may be required to improve the technology.
Fifty patients have been enrolled in five studies; 35 patients have undergone implantation of a total of 79 BION1 devices. Comparisons with surface stimulation in patients who have suffered a stroke with shoulder subluxation and hand contractures show similar improvements in objective measures of efficacy but higher comfort levels for stimulation by implants.

Conclusions
Injected microstimulators represent a promising new class of technology for the rehabilitation of patients with upper motor neuropathies. As the technology evolves, practitioners may be able to use it to facilitate functional reanimation of paralyzed limbs.
Acute microelectrode array implantation into human neocortex: preliminary technique and histological considerations
Authors: House Paul A. , MacDonald Joel D. , Tresco Patrick A. , Normann Richard A. 
Published: February 2011

Object
Researchers at The Center for Neural Interfaces at the University of Utah have designed and produced a silicon-based high-density microelectrode array that has been used successfully in mammalian models. The authors investigate the ability to transfer array insertion techniques to humans and examine the acute response of human cortical tissue to array implantation.

Methods
Six patients who were scheduled to undergo temporal lobectomy surgery were enrolled in an Institutional Review Board–approved protocol. Before the patients underwent lateral temporal cortical resection, one or two high-density microelectrode arrays were implanted in each individual by using a pneumatic insertion device. Cortical tissue was then excised and preserved in formalin. The specimens were sectioned and stained for histological examination.
Pneumatic insertion of a microelectrode array into human cortex in the operating room was feasible. There were no clinical complications associated with implantation and no evidence of significant insertion-related hemorrhage. Tissue responses ranged from mild cortical deformity to small focal hemorrhages several millimeters below the electrode tines. Based on initial results, the insertion device was modified. A footplate that mechanically isolates a small area of cortex and a calibrated micromanipulator were added to improve the reproducibility of insertion.

Conclusions
A high-density microelectrode array designed to function as a direct cortical interface device can be implanted into human cortical tissue without acute clinical complications. Further modifications to the insertion device and array design are ongoing and future work will assess the functional significance of the tissue reactions observed.
Spinal arteriovenous malformations: new classification and surgical treatment
Authors: Zozulya Yuri P. , Slin'ko Eugene I. , Al-Qashqish Iyad I. 
Published: February 2011

Object
Spinal vascular malformations represent rare and insufficiently studied pathological entities characterized by considerable variation. Insufficient study of this disease is connected with the complexity of its diagnosis, which restricts the development of surgical treatments that are differentiated according to the type of malformation. Great difficulties are caused by the lack of a clear structural–hemodynamic classification of spinal arteriovenous malformations (AVMs). At present the classification created between 1991 and 1998 by the combined efforts of different authors is the most widely used one. According to this classification, four categories are distinguishable: Type I, dural arteriovenous fistulas (AVFs); Type II, intramedullary glomus AVMs; Type III, juvenile or combined AVMs; and Type IV, intradural perimedullary AVFs. Vascular tumors are also classified, as follows: hemangiomas, hemangioblastomas, angiosarcomas, hemangiopericytomas, angiofibromas, angiolipomas, and hemangioendotheliomas, as well as cavernous malformations.

Methods
In this study the authors analyze the diagnostic data and results of treatment in 91 patients with AVMs and AVFs who were treated at the Institute of Neurosurgery between 1995 and 2005. The patients' ages ranged from 9 to 83 years; the mean age was 42.9 years. For spinal vascular malformations we devised a classification that took into account the aforementioned features of AVMs: the anatomical characteristics of a malformation and its angiostructural and hemodynamic features. In all patients the neuroimaging modalities used in the investigation of their lesions included magnetic resonance (MR) imaging and selective spinal angiography. Three-dimensional computerized tomography angiography studies were obtained in 14 patients, and MR angiography was used in 17.

Conclusions
For successful surgical treatment of spinal AVMs it is necessary to obtain data about their localization, vascular structure, and hemodynamics that are as complete as possible. This information will promote the use of optimum surgical procedures and the latest methods of microsurgical and endovascular interventions, with treatments differentiated according to the type of malformation. One should try to use the least invasive endovascular approach in these cases,where possible, to occlude the AVM or reduce the intensity of blood flow by means of embolization. To perform an AVM resection or occlusion, one should use a direct approach to the malformation, blocking only the vessels supplying blood to the malformation and preserving the vessels feeding the spinal cord.
Survival after stereotactic biopsy and irradiation of cerebral nonanaplastic, nonpilocytic astrocytoma
Authors: Lunsford L. Dade , Somaza Salvador , Kondziolka Douglas , Flickinger John C. 
Published: February 2011

✓ The authors investigated the outcome of stereotactic biopsy and radiotherapy in 35 consecutive adult patients with nonanaplastic, nonpilocytic astrocytomas who were diagnosed between 1982 and 1992. The median patient age at presentation was 32 years. All received fractionated external-beam radiation therapy (median dose 56 Gy) as the initial management strategy. Additional treatment in two patients included intracavitary irradiation with colloidal phosphorus-32.
Six patients (17%) had documented tumor progression during the follow-up interval and died. Three others died of causes unrelated to their tumor. Median survival after stereotactic biopsy and irradiation was 118 months (9.8 years). Median survival from the time of onset of neurological symptoms was 148 months (12.3 years). Only three patients required delayed cytoreductive surgery.
The outcome of brain astrocytomas, although improved because of earlier diagnosis and therapy, does not substantiate this tumor as having benign behavior; early recognition with neuroimaging, immediate histological diagnosis via stereotactic biopsy, and initial fractionated radiation therapy may provide the potential for longer survival for patients with low-grade astrocytomas. The majority of such surviving patients have a satisfactory quality of life, which is manifested by prolonged normal functional and employment status. The survival data reported in this prospective Phase I–II clinical trial suggest that stereotactic biopsy and radiation therapy are appropriate initial management strategies for astrocytomas.
Preirradiation chemotherapy including “eight drugs in 1 day” regimen and high-dose methotrexate in childhood medulloblastoma: results of the M7 French Cooperative Study
Authors: Gentet J. C. , Bouffet E. , Doz F. , Tron P. , Roche H. , Thyss A. , Plantaz D. , Stephan J. L. , Mottolese C. , Ponvert D. , Carrie C. , Raybaud C. , Brunat-Mentigny M. , Choux M. , Philip T. , Zucker J. M. , Bernard J. L. 
Published: February 2011

✓ The aim of this study was to evaluate the feasibility and efficacy of a protocol that includes “sandwich” chemotherapy, that is, chemotherapy alternated with radiotherapy, and reduced doses of supratentorial irradiation in children with medulloblastoma. Between March 1985 and September 1988, 70 successive children with newly diagnosed medulloblastoma from eight centers were treated in this prospective nonrandomized study. Patients were assigned to two risk groups. Group A included patients with macroscopically complete or subtotal excision, no brainstem involvement, no atypical cells in the cerebrospinal fluid, normal myelography, and who were more than 2 years of age. Group B patients encompassed those who did not fit the criteria for Group A. Two children were excluded from analysis after histological review confirmed ependymoma. Thus, a population of 68 children was selected, with 31 in Group A and 37 in Group B.
Treatment consisted of two courses of the “eight drugs in 1 day” (“8/1”) regimen followed by two courses of high-dose methotrexate (12 g/m2). Radiotherapy was begun during the 7th week after surgery in Group A and during the 5th week in Group B. In patients older than 2 years, the median radiation dose to the posterior fossa, the spinal axis, and the brain was 54 Gy, 36 Gy, and 27 Gy, respectively. Group B patients received postirradiation chemotherapy with four 8/1 courses monthly. The median time from surgery to radiation therapy was 50 days (range 21 to 141 days). One fatality due to chicken pox on Day 102 and one World Health Organization Grade IV infection occurred. The estimated 5- and 7-year disease-free survival (DFS) rates were 62% and 59%, respectively. These were 74% and 62% in Group A and 57% and 57% in Group B. Patient age, extent of resection, and radiation dose to the whole brain had no prognostic value. Patients with metastasis had a nonsignificant trend for a worse prognosis than patients with nonmetastatic disease (7-year DFS 45% vs. 68%, p = 0.11). In Group B, the 7-year DFS rates for children who received more or less than 30 Gy to the brain were 69% and 52% respectively (p = 0.15). There were recurrences in the posterior fossa (37%), spine (20%), and brain (20%). After a review of radiotherapeutic treatments, only one supratentorial failure could be blamed on reduction of the supratentorial radiation dose. This “sandwich” chemotherapy appeared to be feasible and did not show adverse survival data when compared to other series.
The Brigham Diary of Loyal Davis: a portrait of Harvey Cushing and a neurosurgical acolyte
Authors: Davis Richard A. 
Published: February 2011

✓ At 27 years of age, Loyal Davis wrote the Brigham Diary while training as an Associate in Surgery with Dr. Harvey Cushing. The diary is a daily record of the Cushing neurosurgical service between 1923 and 1924. The literary tone of the document is one of youthful enthusiasm and candor. Its contemporary portrayal of Harvard University's third Moseley Professor displays a demanding surgeon and scholar whose primary concern was the care of his patients and who taught the meticulous techniques of neurosurgery by example. In contrast to the experiences offered by current neurosurgical residency programs, Loyal Davis examined 107 patients, observed 81 operations, assisted Dr. Cushing during 23 operations, assisted Dr. Gilbert Horrax in 13 operations, and never performed an operation independently during his year at the Peter Bent Brigham Hospital. Despite these technical constraints, the young assistant learned the Cushing method of surgery and skilled patient care and was encouraged to continue laboratory investigations. Davis also emulated Cushing's exacting method of preparation of medical manuscripts, which were characterized by scientific innovation and an engaging literary style.
The diary shows that Cushing often held inflexible surgical and scientific opinions and was contentious in their defense. These opinions were modified only when he was presented with unequivocal facts. The young surgeon sought Cushing's approval which carried a genuine but restrained benevolence.
Harvey Cushing's impression on Davis was lasting and profound. The diary conveys the philosophy that uncompromised discipline is a necessary virtue and hard work is full satisfaction in itself. In the following years, Loyal Davis systematically patterned his surgical and scholarly endeavors after those of Harvey Cushing, an exemplar whose unstinting resolve was the pursuit of excellence.
Cadaveric study for placement of occipital condyle screws: technique and effects on surrounding anatomic structures
Authors: La Marca Frank , Zubay Geoffrey , Morrison Thomas , Karahalios Dean 
Published: February 2011

ObjectThe occipital condyle has never been studied as a viable structure that could permit bone purchase by fixation devices for occipitocervical fusion. The authors propose occipital condyle screw placement as a possible alternative to conventional occipitocervical fixation techniques.MethodsSix adult cadaver heads (12 total occipital condyles) were studied, and the StealthStation image-guidance system was used for preoperative planning of occipital condyle screw placement. Morphometric studies of the occipital condyle were performed. A 3.5-mm Vertex screw was then placed in the occipital condyle with image-guided assistance in 3 specimens. Operations in the remaining 3 specimens proceeded using anatomical markers and calculated degrees of angulation for screw placement with a free-hand technique. Postoperatively the cadaver heads were rescanned and reanalyzed to determine the success of screw placement and its effect on hypoglossal canal volume.ResultsAll screws were successfully placed with no sign of lateral or medial cortical breach. Two screws had bicortical purchase. There was no change in hypoglossal canal volume in any specimen.ConclusionsOccipital condyle screw placement is a safe and viable option for occipitocervical fixation and could be a preferred procedure in selected cases. However, further biomechanical studies are required to compare its reliability to other more established techniques.
Biomechanical evaluation of different asymmetrical posterior stabilization methods for minimally invasive transforaminal lumbar interbody fusion
Authors: Schleicher Philipp , Beth Paavo , Ottenbacher Andreas , Pflugmacher Robert , Scholz Matti , Schnake Klaus John , Haas Norbert P. , Kandziora Frank 
Published: February 2011

ObjectBeside several other advantages, the transforaminal approach for lumbar interbody fusion offers the possibility of reducing surgical trauma by limiting the approach to only 1 side. This requires posterior stabilization methods, which are applied without the need to damage contralateral muscles and soft tissues. The goal in this study was to compare different posterior stabilization methods for minimally invasive transforaminal lumbar interbody fusion (TLIF) biomechanically.MethodsStiffness testing was performed in 8 fresh-frozen human cadaveric lumbar spine motion segments, including the following sequentially tested configurations: 1) native motion segment; 2) TLIF and bilateral pedicle screw (PS) construct; 3) TLIF and ipsilateral PS construct; 4) TLIF and ipsilateral PSs plus contralateral translaminar facet screws according to the Magerl technique; and 5) TLIF and ipsilateral PSs plus contralateral lumbar facet interference screw (LFIS).ResultsIn extension, the unilateral range of motion (uROM) and elastic zone (EZ) were significantly lower than native motion segments for bilateral PS and LFIS. There were no significant differences among the different stabilization methods. In flexion, uROM and EZ were significantly lower than the native segment in the spines treated with bilateral PSs and translaminar facet screws. The LFIS differed from the native segment in EZ only. Again, there were no significant differences between the different posterior stabilization methods. In lateral bending, the EZ of spines treated with uni- and bilateral PS differed significantly. There were no additional significant differences. In rotation, the stiffness values of bilateral PS were significantly higher than native, unilateral PS, and LFIS. The comparison between ipsi- and bilateral PS showed a tendency, but not a significant difference for uROM and EZ. There was no statistically significant evidence that the TLIF method led to an asymmetrical motion behavior in our study.ConclusionsBilateral PS augmentation offers significantly more stability than unilateral PSs in the majority of the test modes. There was no significant difference between the other tested methods. All tested stabilization methods could achieve at least the stability of the native segment.