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Results for “Neuronavigation”

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At least 505 records · Page 28Linked to original sources

PubMed2003

Resective surgery for hypothalamic hamartoma.

Hypothalamic hamartoma presents with precocious puberty, epilepsy or both. There are two epileptic syndromes, one presenting initially in infancy with gelastic seizures evolving rapidly into a syndrome with multiple seizures, developmental delay and a moderate to severe behaviour disorder. The other presents later with a milder epileptic syndrome, again usually including gelastic seizures, but with normal intellect and behaviour. Magnetic resonance imaging identifies and gives a detailed anatomical picture of these lesions. Direct surgery, using microsurgical techniques and neuronavigation guidance has been used for these lesions. Three surgical approaches have been used, one lateral pterional, another midline frontal through the lamina terminalis and a third is a transcallosal interforniceal approach. In addition a disconnection procedure, usually pterional, aims to disconnect the lesion without the risks of major resection. The transcallosal interforniceal approach is the most successful with 69% of patients seizure-free. There are complications in about 24% of patients, the same as other approaches, but the complications are milder and include fewer neurological deficits than the other routes. Alternate strategies include stereotactic radiosurgery and radiofrequency ablation under stereotactic control.

Adolescent↗

PubMed2003

[Pituitary adenomas: neurosurgical treatment].

Due to their diversity, pituitary adenomas represent an interdisciplinary therapeutic challenge in regard to endocrinology, radiology and neurosurgery. Advanced radiological methods such as magnetic resonance imaging (MRI) and the possibility of three-dimensional reconstruction have profoundly improved surgical planning and intraoperative neuronavigation. With the application of modern surgical techniques like endoscope-assisted microsurgery or pure endoscopic surgery further improvements in the treatment of pituitary adenomas at difficult locations can be expected. Major prognostic factors predicting surgical outcome are extension of the adenoma and invasivity into adjacent structures. Both may be perfectly visualized by high-resolution MRI. The proliferation marker MIB-1 as a parameter of growth-rate and invasivity of pituitary adenomas provides information for postoperative management in terms of additional treatment and follow-up imaging. The current management of pituitary adenomas is discussed according to the different therapeutic options available and new developments are presented.

Adenoma↗

PubMed2004

Multiple sclerosis and gliomas. Clinical remarks on 10 cases and critical review of the literature.

The association between multiple sclerosis and tumours of the central nervous system is unusual. The authors analyzed the clinico-pathological elements of the correlation. The pertinent literature on this subject is critically reviewed. Ten cases of patients with an history of multiple sclerosis for more than 15 years and a clinical and radiological evidence of brain tumour were submitted to surgery in order to remove the lesion and/or to chemo- and radiotherapy. The various aspects of the association were studied in detail. A patient with multiple sclerosis, particularly with atypical symptoms, should be evaluated by an annual MRI investigation with intravenous paramagnetic contrast medium. The diagnostic work-up should be: clinical and radiological assessment; MRI in the event of atypical symptoms; Sstereotactic or neuronavigation-aided biopsy in any suspected lesions. Patients with multiple sclerosis and glioma present survival times identical to those observed in patients not suffering from multiple sclerosis. The coexistence of multiple sclerosis and brain tumours does not seem to influence the clinical evolution of either of these pathologies. We believe that it is important to achieve an early diagnosis of brain tumour in such patients with a clinical and neuroradiological follow up, so that they can be treated promptly.

Adult↗

PubMed2004

[Hypoglossal neurilemmoma: current experience in diagnosis and treatment].

OBJECTIVE: To improve the diagnosis and treatment of hypoglossal neurilemmoma (HGN). METHODS: The data of 10 patients with HGN were retrospectively reviewed, 5 of 10 patients (early group) had been reported previously. A comparison of treatment strategy between early and latter group was made. RESULTS: Typical hemiatrophy of the tongue presented in all 10 patients, hypoglossal canal could be showed in the bone window of CT, which, however, might not confirm the existence of tumor if it is very small. MRI was the optical choice for diagnosis. Among the early 5 cases with HGN which were all of dumbbell type, the intracranial part and the extracranial part of the tumor in 2 cases were removed by stages, 3 cases were operated via the far-lateral approach, of which 1 was via trans-condylar approach and 2 were via trans-supracondylar approach; the 5 tumors were removed subtotally except 1 totally; CSF leakage and intra-cranial infection after operation occurred in 1 case; the rating of Karnofsky Prognosis Scale was good in 4 cases and dead in 1 case. However, among the latter 5 cases, 4 cases including 2 of dumbbell type, 1 of intra-cranial type and 1 of intracanal type were operated via the modified far-lateral approach, of which 1 was via trans-condylar approach and 3 were via trans-supracondylar approach; and the tumor of extracranial type in the last case was resected twice via transcervical approach, being removed subtotally in the first operation followed by total removal with the aid of neuronavigation and neuroendoscopy in the second operation when it failed to react to the treatment of gamma knife; the 5 tumors were removed totally except 1 subtotally.; all postoperative courses were uneventful.; follow up was performed successfully in 4 cases, the rating of Karnofsky Prognosis Scale was excellent in 3 cases and fair in 1 case. The outcomes of the latter 5 cases resected via modified approach were better than those of the early 5 cases. CONCLUSION: HGN is extremely rare and it is difficult to treat it. To achieve a good operative outcome, it is very important to design the approach individually based on its location and size and operate mini-invasively and resect tumor totally as possible as can in the primary stage.

Adult↗

PubMed2005

[Successful treatment of Cushing disease with the sphenoid sinus of conchal type: usefulness of inferior petrosal sinus sampling and STEALTH navigation system: a case report].

We report a case of Cushing disease whose microadenoma was not identified by MRI with dynamic study and whose sphenoid sinus was conchal in type. Venous sampling test in the bilateral inferior petrosal sinus demonstrated ACTH hypersecretion on the right side. The patient underwent transsphenoidal surgery. A poorly pneumatized sphenoid sinus was drilled effectively, guided by the STEALTH navigation system. After the first operation, the patient's serum ACTH concentration was still high, suggesting that tumor removal was incomplete. Then she underwent the second operation and the residual tumor was completely removed with the assistance of the STEALTH navigation system again. Postoperatively, her serum ACTH concentration dropped below 5 pg/ml. In this case, inferior petrosal sinus sampling was extremely helpful for the diagnosis of Cushing disease, and operations were able to be performed safely using the neuronavigation system in drilling of the incompletely pneumatized sphenoid sinus.

Adenoma↗

PubMedDate not supplied

Iron particles enhance visualization of experimental gliomas with high-resolution sonography.

BACKGROUND AND PURPOSE: Intraoperative MR imaging and sonography are used for navigation during neurosurgical procedures. The purpose of this experimental study was to evaluate the potential of high-resolution sonography using superparamagnetic iron oxide (SPIO) particles as a contrast medium to delineate brain tumors and to relate these findings with those of MR imaging. METHODS: C6 gliomas were implanted in 36 rats. Eleven days after tumor implantation, the animals underwent MR imaging with a 1.5-T MR imaging unit. Twelve animals received gadopentetate dimeglumine immediately before the MR examination, 12 animals were injected with SPIO particles 24 hours before MR imaging, and 12 animals received no contrast agent. Immediately after MR imaging, the animals were sacrificed and their brains were removed and placed in saline. Sonography was performed instantly after brain removal. Brains were embedded in paraffin, and sections were stained for iron with Perl's stain and for macrophages with ED-1 immunohistochemistry. RESULTS: At MR imaging, the tumors appeared hyperintense on T2-weighted and gadolinium-enhanced T1-weighted images. After application of SPIO particles, they became markedly hypointense on T2-weighted images and hypo- to hyperintense on T1-weighted images. On sonograms, gliomas were iso- to slightly hyperechoic to normal brain parenchyma on nonenhanced and on gadolinium-enhanced images. After application of SPIO particles, tumors became markedly hyperechoic and were distinctly demarcated from the surrounding brain tissue. CONCLUSION: SPIO particles improved the detection and demarcation of the experimental gliomas on sonograms, which may improve intraoperative neuronavigation with sonography.

Animals↗

PubMed2005

[A case of high grade astrocytoma arising in the hand area of precentral gyrus].

A 23-year-old man presented with the right upper monoparesis. The right little finger paresis was apparent at first, and ring finger two weeks later, and middle, index, thumb were simultaneously four weeks later. Then the monoparesis gradually progressed to the proximal upper limb. Magnetic resonance imaging showed a small lesion at the knob of the left precentral gyrus. The lesion was low-intensity on T1-, and high-intensity on T2-weighted images, and clearly detected on high-intensity on FLAIR images, but showed no enhancement by gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Angiography and thallium scintigraphy showed no remarkable findings. Proton MR spectroscopy demonstrated lower N-acetylaspartate (NAA) and higher choline (Cho) level compared to the contralateral cortico-subcortical area. Diffusion weighted images demonstrated low apparent diffusion coefficient (ADC) value and high intensity on b = 1,000. To clarify the diagnosis of the lesion, we performed open biopsy by using the neuronavigation system to detect the lesion accurately and minimize the biopsy. Histological examination revealed an high grade astrocytoma with high MlIB-1 index over 30%. The progressive symptoms were due to highly infiltrative and proliferative nature of the tumor arising in the focal hand area of the primary motor cortex, according to the homunculus. We discuss herein the neuroimagings of the case that was considered to be in the initial stage of a malignant tumor.

Adult↗

PubMedDate not supplied

[Motor cortex stimulation in the treatment of the central pain: a case report].

Motor cortex stimulation (MCS) is one of the methods of treatment in chronic pain syndromes. According to recent clinical studies effectiveness of this mode of treatment in the central pain has been proved. This article reports the first case of a patient with the thalamic syndrome treated with MCS in the Clinical Department of Neurosurgery in Military Clinical Hospital in Bydgoszcz. The procedure of implantation was performed with the guidance of a frameless neuronavigation system which served for localization of the precentral gyrus. Correct placement of the electrode was confirmed by intraoperative stimulation. As a result of the treatment a decrease of pain and improvement of psychosocial state has been achieved.

Chronic Disease↗

PubMed2006

[Meningiomas with skull bone involvement].

One of factors responsible for meningioma recurrencies is tumorous involvement of calvarial and basal bone structures. Primary intraosseous meningiomas should be distinguished from secondary involvement in prevailing intracranial tumor and hyperostotic reactive changes. The paper is based on prospective study of 167 patient operated on for intracranial meningioma. Based on clinical investigation, radiological and intraoperative data bone invasion was suspected in 20 patients and histologically confirmed in 17. In 14 patients bone involvement was secondary, meningothelial hamartoma was described in one patient and in 2 patient primary intraosseous meningioma was found. Prevalence of tumors to periorbital area and bone sutures is confirmed. Neuronavigation is used to optimise tumor resection and limit the risk for neurovascular structures. Results were good in 87.5% of patients and poor in 12.5% of patients (extent of tumor and general condition). Discussion provides analysis of intraosseous meningiomas formation, pathological classification (Lang), causes of bone invasion and surgical possibilities. It is necessary to undeline the problems of intraosseous meningiomas both from the aspects of diagnosis and subsequent treatment.

Adult↗

PubMed2006

[History of epilepsy surgery at The Hospital for Sick Children in Toronto, Canada].

OBJECTIVE: To review the development of epilepsy surgery for pediatric patients with intractable epilepsy at The Hospital for Sick Children in Toronto, Canada. METHODS: We retrospectively collected and reviewed published papers regarding pediatric epilepsy surgery since 1930's. RESULTS: First, McKenzie started a hemispherectomy for children. Hendrick established anatomical hemispherectomy for pediatric patients with hemiparesis and intractable seizures since 1964. Hoffman performed anterior temporal lobectomy and neocortical temporal resection for lesional tempolal lobe epilepsy with or without mesial temporal sclerosis since 1974. Thereafter, multimodal neuroimaging studies of CT scan, MRI, and XenonCT, SPECT and PET have been used to identify and remove the epileptogenic lesion and zone. In 1996, magnetoencephalography (MEG) was introduced to localize interictal spike sources and somatosensory evoked fields for children with intractable seizures. Snead and Rutka started subdural grid electrodes that were constructed by scalp video EEG, MRI and MEG findings. The clustered MEG spike source coregistered with the intraoperative neuronavigation system delineated the epileptogenic zone requiring completely excision for neocortical lesional epilepsy from 2000. CONCLUSION: The pediatric epilepsy surgery at the Hospital for Sick Children has been progressing from anatomical hemispherectomy to complete clusterectomy of MEG spikes sources that localized the epileptogenic zone. Cortical excision, lobectomy, hemisphelotomy, corpus callosotomy and vagal nerve stimulation have been applied to appropriate seizure types identified by advanced neurodiagnostic modalities. We furthermore develop non-invasive methods for localizing and understanding the epileptic network in pediatric epilepsy patients with developing brain.

Canada↗

PubMedDate not supplied

[Results of radical removal of malignant cerebral gliomas, by using computer-assisted navigation, followed by adjuvant therapy].

A retrospective cohort analysis of the results of treatment of patients with malignant gliomas was made in 2 groups, each comprising 43 patients. In Group 1, the tumors were radically removed under neuronavigation guidance ("Voyager SX"). In Group 2 where the patients were operated on by the same team of surgeons who did not employ computer-assisted navigation technologies. The results of different adjuvant therapy regimens were analyzed in patients after radical tumor removal under navigation guidance (Group 1). In its first subgroup, 24 patients with anaplastic astrocytes were postoperatively irradiated (60 Gy), followed by treatment with temodal (200 mg/m2 (mean 6 courses). In the second subgroup, 12 patients received chemoradiotherapy (temodal, 75 mg/m2 daily + irradiation), followed by courses (n=6) of temodal, 200 mg/m2). In the third subgroup, 7 patients were treated with fotemustin (200 mg/m2 (induction) + 5 cycles). The computer-assisted technologies substantially improve a postoperative outcome in patients with malignant glionas. Current chemoradiotherapy is relatively safe and prolongs a relapse-free interval with a high quality of life. Further studies call for the efficiency of different adjuvant therapy regimens after radical surgery.

Adult↗

PubMed1991

[Three dimensional CT reconstruction system on a personal computer].

A new computer system to produce three dimensional surface image from CT scan has been invented. Although many similar systems have been already developed and reported, they are too expensive to be set up in routine clinical services because most of these systems are based on high power mini-computer systems. According to the opinion that a practical 3D-CT system should be used in daily clinical activities using only a personal computer, we have transplanted the 3D program into a personal computer working in MS-DOS (16-bit, 12 MHz). We added to the program a routine which simulates surgical dissection on the surface image. The time required to produce the surface image ranges from 40 to 90 seconds. To facilitate the simulation, we connected a 3D system with the neuronavigator. The navigator gives the position of the surgical simulation when the surgeon places the navigator tip on the patient's head thus simulating the surgical excision before the real dissection.

Brain↗

PubMed1990

Computer-guided laser for neurosurgery.

On the basis of over 40 neurosurgical laser operations, including CO2, Nd-YAG and simultaneous CO2/Nd-YAG laser procedures, a computer-guided system for spatial control of the laser beam has been developed. The pilot laser has several modes: it can direct the neurosurgeon along the central axis of the surgical microscope to stereotactically determined point-like targets or outline selected layers of underlying volume targets onto superficial surfaces such as scalp and cortex and onto the tissue at the appropriate depth. The active treatment laser can be guided by preoperative CT/MRI or intraoperative ultrasound image data for layer-by-layer resection of tumor. The laser system can be connected to the surgical field by rigid stereotactic means or by neuronavigator. In the present system, a special brain surgery adapter coordinates the imaging system and laser to the surgical field. Thus, the laser system can be used for image-guided surgical orientation, for demarcation of lesions and for actual layer-by-layer removal of tumor.

Brain Neoplasms↗

PubMed1994

Complex technical methodologies and their applications in the surgery of intracranial meningiomas.

As neurosurgery moves into the twenty-first century, improved visualization/localization techniques, neuromonitoring, and advanced instrumentation will become standards of care for all intracranial procedures. This article has focused on current available technologies that can be used to facilitate operations on intracranial meningiomas. Preoperative anatomic localization with MR imaging, CT, MR angiography, and angiography are standard techniques. Preoperative functional assessments with MR imaging, magnetic source imaging, PET, and functional MR imaging are crucial to recognize and preserve eloquent adjacent cortex. Pathologic correlations with preoperative imaging (i.e., MR imaging) may help to predict the histopathology. Perioperative rehearsal of the operation can be performed. Intraoperative anatomic localization is important to minimize the craniotomy, dural opening, and passage through normal neural structures. An impressive array of new technologies are currently available, including real-time ultrasonography, frame-based stereotaxy (CT, MR imaging PET), frameless stereotaxy (acoustic localization, neuronavigators, real-time visualization), robotics, neuroendoscopy, and intraoperative dye administration. Increased understanding of the function and individual variability of the human cortex underscores the importance of intraoperative functional localization by electrocorticography and optical imaging. Continuous intraoperative neuromonitoring of sensory (SSEPs, BAERs, visual evoked potentials) and motor evoked potentials is now standard during many intracranial procedures. Complex adjunctive instrumentation, such as the ultrasonic aspirator and the laser, are part of the contemporary armamentarium for meningioma surgery. As we have stated in a previous article, "Developmental trends imply realization of three major directions of technical neurosurgery: (1) precise preoperative simulation, (2) minimization or avoidance of transcranial operative corridors, [and] (3) increased refinement of technical adjuvants--both physical and molecular." The end point of these technical advances is to improve precision and safety and will enhance the outcome in each surgical procedure so that one day we will be able to operate on patients with intracranial lesions with minimal morbidity.

Brain↗

PubMed1996

[Stereotaxically guided versus ultrasound guided surgery--a comparative report of experiences].

Localisation and approach are the keys of surgery on brain tumours. Apart from the up and coming neuronavigational devices, stereotactical and ultrasound guidance are well established methods in locating intracranial tumours and in selecting the optimal approach for resection. Nevertheless it is not clear, which guidance tool is more practicable in the daily routine. Both methods have been used in our department since 1989. During the last six and half years we have operated on 1314 patients suffering from intracranial tumours. In 148 cases we have used either stereotactical (n = 37) or ultrasonic (n = 111) intraoperative guidance. The performing surgeon had documented ease of use, accuracy and users acceptance of the chosen guidance tool. The data were summarised together with the patients history and images in to a descriptive report. Since 1992 we noted a steady increase in guiding operations from 4% to 24%, mainly due to the more frequent use of ultrasound guidance. Saving time, easy handling, accuracy and plausible guidance with real time pictures have been the major advantages in favouring ultrasound guidance. Additionally, the freedom in choosing the appropriate approach seems to be essential. To achieve full advantage of all these benefits, experience and individual expertise are necessary. Conversely, the high accuracy of stereotactic guidance is not within the reach of the ultrasound, which is sufficient to guide the operation. According to our experiences, we recommend intraoperative ultrasound as an easy guiding tool. Except a few cases, this guiding tool seems to be superior to the stereotactic localisation of intracranial lesions.

Brain Mapping↗

PubMed1997

[Familial astrocytoma associated with von Recklinghausen's disease: report of two cases].

Two cases of astrocytoma associated with von Recklinghausen's disease (neurofibromatosis type; NF-1) were reported. The first case wes a 60-year-old man who had been diagnosed as von Recklinghausen's disease on the basis of skin findings. Magnetic resonance imaging (MRI) showed a tumor in the left temporal lobe. Partial removal was performed with neuronavigator, and because of the existence of Rosenthal fiber the histological diagnosis was pilocytic astrocytoma. Radiation therapy was performed. The second case was a 6-year-old boy suffering from headache and left hemiparesis including his face. MRI showed a tumor with a cyst in the right thalamus and obstructive hydrocephalus. Initially CT-guided stereotactic biopsy was performed, and the histological diagnosis, on the basis of increased cellularity, pleomorphism and nuclear atypia without necrosis or vascular proliferation, was anaplastic astrocytoma. Radiation and chemo-immuno therapy were carried out after V-P shunt. It is well known that von Recklinghausen's disease (NF-1) is often associated with optic glioma (5-36%). In the literature, the glioma seldom occurs in other parts of the brain, supratentorial glioma especially is rare. Only two familial cases of supratentorial glioma associated with von Recklinghausen's disease have been reported. The prognosis of supratentorial glioma associated with NF-1 was poor in these reports. In this paper, the diagnostic and therapeutic problems are discussed.

Astrocytoma↗

PubMed1996

Molecular neurosurgery using gene therapy to treat malignant glioma.

In the last decade, the prognosis of brain tumor patients has dramatically improved due to recent advances in microsurgical techniques and the development of functioning neuroimaging, computer-assisted neuronavigation, endoscopic surgery, intravascular surgery and radiosurgery. According to a report by the Committee of Brain Tumor Registry of Japan, the ten year survival rate of patients with benign brain tumors (meningioma, neurinoma and pituitary adenoma) is more than 95%. In contrast, patients with glioma (which constitute 33% of primary brain tumor cases) still have a poor prognosis, especially in the case of malignant (anaplastic astrocytoma and glioblastoma). This poor prognosis is related to the fact that malignant glioma cells aggressively infiltrate into normal brain tissues, making total removal of the tumor impossible. The median survival time of glioblastoma patients is less than 2 years, despite multimodality treatment with extensive surgical resection and adjuvant therapies using radiation and immunochemotherapy. In order to overcome this formidable neoplasm, the effectiveness of molecular neurosurgery using gene therapy has been investigated since 1992. In this paper, molecular genetic studies and the current state of gene therapy for malignant brain tumors are described, and the future direction of this fascinating approach is discussed.

Animals↗

PubMed1997

[Computer-assisted orthopedic surgery. From pedicle screw insertion to further applications].

Computer assisted orthopaedic surgery is a new but rapidly evolving field. Based on previous research and development in the area of stereotactic neuronavigation a few groups have adapted these technologies for the image interactive insertion of pedicle screws. The present paper summarizes past and current work in the field of computer assisted orthopaedic surgery and describes the state of the art of research and future innovations, particularly in in vivo applications.

Bone Screws↗