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Biomedical subjects

E Seigneuret

Publications and source records attributed to E Seigneuret.

13 recordsLinked to original sources
PubMed2006

Robotics in neurosurgery: which tools for what?

Robots are the tools for taking advantage of the skills of computers in achieving complicated tasks. This has been made possible owing to the "numerical image explosion" which allowed us to easily obtain spatial coordinates, three dimensional reconstruction, multimodality imaging including digital subtraction angiography (DSA), computed tomography (CT), magnetic resonance imaging (MRI) and magneto encephalography (MEG), with high resolution in space, time, and tissue density. Neurosurgical robots currently available at the operating level are being described. Future evolutions, indications and ethical aspects are examined.

Humans↗
PubMed2006

Surgical therapy for Parkinson's disease.

High frequency stimulation (HFS) has become the main alternative to medical treatment, due to its reversibility, adaptability, and low morbidity. Initiated in the thalamus (Vim) for the control of tremor, HFS has been applied to the Pallidum (GPi), and then to the subthalamic nucleus (STN), suggested by experiments in MPTP monkeys. STN-HFS is highly efficient on tremor, rigidity and bradykinesia and is now widely applied. Criteria for success are correct patient selection and precise electrode placement. The best outcome predictor is the response to Levodopa. The mechanisms of action might associate inhibition of cell firing, jamming of neuronal message and exhaustion of synaptic neurotransmitter release. The inhibition of glutamate STN release could be neuroprotective on nigral cells. Animal experiments support this hypothesis, not contradicted by the long-term follow up of patients. Neuroprotection might have considerable impact on the management of PD patient and warrants clinical trials.

Animals↗
PubMed2004

[Persistent primitive trigeminal artery associated with brain cavernoma. Case report].

Among cases of embryonic carotid-basilar anastomosis which may persist after birth, persistent trigeminal artery is the most common. It has been associated with a wide variety of intracranial abnormalities. We are unaware of any other reported association with cavernoma. We report a young woman who experienced seizures following spontaneous abortion. A CT scan disclosed a right frontal hematoma. MRI revealed a cavernoma associated with a persistent trigeminal artery. The cavernoma was removed through a frontal approach. The aim of the present case is to report another type of lesion fortuitously associated with a persistent trigeminal artery.

Adult↗
PubMed2004

[Indications and risks of neurosurgical techniques for drug-resistant partial epilepsy in adults].

Many different surgical procedures are performed for medically refractory partial epilepsy. Some surgical therapies are performed to cure the epilepsy (for example unifocal epilepsy), others are palliative procedures. To cure epilepsy, temporal lobectomy is the most common surgical procedure. The different techniques are shortly described, indications and complications are discussed.

Anticonvulsants↗
PubMed2000

A data fusion environment for multimodal and multi-informational neuronavigation.

OBJECTIVE: Part of the planning and performance of neurosurgery consists of determining target areas, areas to be avoided, landmark areas, and trajectories, all of which are components of the surgical script. Nowadays, neurosurgeons have access to multimodal medical imaging to support the definition of the surgical script. The purpose of this paper is to present a software environment developed by the authors that allows full multimodal and multi-informational planning as well as neuronavigation for epilepsy and tumor surgery. MATERIALS AND METHODS: We have developed a data fusion environment dedicated to neuronavigation around the Surgical Microscope Neuronavigator system (Carl Zeiss, Oberkochen, Germany). This environment includes registration, segmentation, 3D visualization, and interaction-applied tools. It provides the neuronavigation system with the multimodal information involved in the definition of the surgical script: lesional areas, sulci, ventricles segmented from magnetic resonance imaging (MRI), vessels segmented from magnetic resonance angiography (MRA), functional areas from magneto-encephalography (MEG), and functional magnetic resonance imaging (fMRI) for somatosensory, motor, or language activation. These data are considered to be relevant for the performance of the surgical procedure. The definition of each entity results from the same procedure: registration to the anatomical MRI data set (defined as the reference data set), segmentation, fused 3D display, selection of the relevant entities for the surgical step, encoding in 3D surface-based representation, and storage of the 3D surfaces in a file recognized by the neuronavigation software (STP 3.4, Leibinger; Freiburg, Germany). RESULTS: Multimodal neuronavigation is illustrated with two clinical cases for which multimodal information was introduced into the neuronavigation system. Lesional areas were used to define and follow the surgical path, sulci and vessels helped identify the anatomical environment of the surgical field, and, finally, MEG and fMRI functional information helped determine the position of functional high-risk areas. CONCLUSION: In this short evaluation, the ability to access preoperative multi-functional and anatomical data within the neuronavigation system was a valuable support for the surgical procedure.

Adult↗
PubMed2000

[Neurological outcome of 152 surgical patients with spinal metastasis].

BACKGROUND AND PURPOSE: The aim of this study is to evaluate retrospectively the benefit of the surgical spinal decompression in 152 patients with spinal metastasis. METHODS: Based on clinical notes and GP inquiry, we determined the actuarial survival curve, and assessed the pain level one month post-operatively and the motor, the sensory and sphincter distrurbances three months after surgery. RESULTS: Thoraco-lumbar lesions were usually treated using a posterior approach, with a laminectomy and if necessary an osteosynthesis. Cervical lesions were treated with an anterior approach, i.e. a corporectomy and a methylmetacrylate stabilization. Sixty eight percent of patients (103/152) had pre or postoperative radiotherapy. After the surgical decompression for a spinal metastasis, our study demonstrated an improvement in sensory status (31 % of the patients), in motor ability (56 %), in sphincter function (51 %), and a decrease in the pain intensity in 47 % of the patients. Among 83 patients who could not walk on admission (grade A, B and C of Frankel), 52 % recovered a gait function 3 months post operatively. The best benefit after surgery concerned grade C patients, of which 71 % recovered the gait function. Two percent of the patients had postoperative worsening of their motor strength. No operative mortality was noted, and the postoperative mortality rate was 3 % at 7 days and 9 % at 30 days. The analysis of the actuarial survival curve demonstrated a mean follow up of 3.7 years. The mean survival time was 12 months with 25 % of patients surviving 2 years. CONCLUSION: Surgical decompression is effective in relieving neurological symptoms from spinal metastasis. In our experience a complete motor deficit does not seem to be a good surgical indication because of the lack of postoperative improvement.

Adult↗
PubMed2000

[Sulcal identification and neuronavigation in supratentorial cavernoma surgery].

We present the use of cortical sulci, segmented from magnetic resonance imaging, in image guided neurosurgery. Sulcal information was transferred to a surgical microscope with enhanced reality features. This assistance was used for the resection of supratentorial cavernomas (7 patients). Sulci were semi-automatically segmented from 3D MRI data sets. Sulci close to the cavernoma were selected and transferred to the neuronavigation system which allows the superimposition of graphics into the right ocular of the microscope. Selected sulci were displayed on the workstation and superimposed into the ocular of the microscope. Cortical sulci proved to be useful for the recognition of the anatomical environment. The superimposed sulci helped to optimize location and size of the skin incision as well as to guide the access to the cavernoma by using the course of a sulcus as indirect trajectory.

Adult↗
PubMed1999

[Neurosurgical multicenter study of cerebral metastases (Neurosurgical departments of Paris Beaujon, Paris Sainte-Anne, Strasbourg)].

We report a multicentric outcome study of cerebral metastases in 174 patients collected consecutively in three neurosurgical centers in France. Age and condition of patients allowed surgical operation; the sex ratio was 1.67. The revelation mode was usual. However tumoral hemorrhage frequency was 3.4%. Primitive cancers were usual cancers as in oncological series with a higher proportion of radioresistant metastases. Mean dimension was 30 mm with mean of 1. 25 metastases per patient. Supratentorial localization was more frequent and the metastasis revealed cancer in 40% of cases. Global median survival was 12.1 months. Factors correlated with the survival in our series of patients with cerebral metastases were: solitary cerebral metastasis, extracerebral extension of cancer, treatment of primitive cancer, complete excision and post operative cerebral radiotherapy.

Adolescent↗
PubMed1993

Chronic VIM thalamic stimulation in Parkinson's disease, essential tremor and extra-pyramidal dyskinesias.

Stereotactic thalamotomy of the VIM (ventral intermediate) nucleus is considered as the best neurosurgical treatment for Parkinsonian and essential tremors. However, this surgery, especially when bilateral, still presents a risk of recurrence and neurological complications. We observed that acute VIM stimulation at frequencies higher than 60 Hz during the mapping phase of the target suppressed the tremor of Parkinson's disease (PD) and essential tremor (ET). This effect was immediately reversible at the end of the stimulation. This was initially proposed as an additional treatment for patients already thalamotomized on the contralateral side, and then extended as a regular procedure for extra-pyramidal dyskinesias. Since January 1987, we implanted 126 thalami in 87 patients (61 PD, 13 ET, 13 dyskinesias of various origins). Deep brain stimulation electrodes were stereotactically implanted under local anaesthesia, using stimulation and micro-recording to delineate the best site of stimulation. Electrodes were subsequently connected to implantable programmable stimulators. The optimal frequency was around 130 to 185 Hz. The results (evaluated by a neurologist from 0 = no effect to 4 = perfect relief) are related to the type of tremor. Altogether, 71% of the 80 patients benefited from the procedure with grade 3 and 4 results. In 88% of the PD cases, the results were good (grade 3) or excellent (grade 4) and stable with time. Rigidity was moderately for a long improved but akinesia was not. The same level of improvement was observed in 68% of the ET patients and only in 18% of the other types of dyskinesias.(ABSTRACT TRUNCATED AT 250 WORDS)

Basal Ganglia Diseases↗