Localization of hand sensory function to the pli de passage moyen of Broca

2004 ◽  
Vol 101 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Warren W. Boling ◽  
André Olivier
Keyword(s):  
Three Dimensional ◽  
Central Area ◽  
Sensory Function ◽  
Content Type ◽  
Positron Emission ◽  
Surface Reconstructions ◽  
Highly Correlated ◽  
Sensory Activation ◽  
Pet Scans ◽  
Fine Print

Object. The goal of this study was to identify a reliable landmark for hand sensory function in the central area. Methods. Hand sensory activation on positron emission tomography (PET) scans was analyzed in 27 patients. Each PET study was coregistered with the patient's magnetic resonance image and analyzed in two-dimensional and three-dimensional cortical surface reconstructions to define anatomicofunctional relationships. Conclusions. The substratum of hand sensory function is a prominent fold of cortex elevating the floor of the central sulcus and connecting the pre- and postcentral gyri. Broca named this cortical fold the pli de passage moyen, and hand motor function has been localized to the precentral component of this structure. In this study the authors demonstrate that hand sensory function is highly correlated with the postcentral component of the pli de passage moyen, and that this structure is a reliable cortical landmark for identifying the aforementioned function.

Functional topography of the low postcentral area

2002 ◽  
Vol 97 (2) ◽  
pp. 388-395 ◽  
Author(s):  
Warren Boling ◽  
David C. Reutens ◽  
André Olivier
Keyword(s):  
Three Dimensional ◽  
Central Area ◽  
Magnetic Resonance Images ◽  
Sensory Function ◽  
Lower Face ◽  
Content Type ◽  
Sensory Area ◽  
Positron Emission ◽  
Postcentral Gyrus ◽  
Fine Print

Object. The goal of this study was to establish a reliable method for identification of face and tongue sensory function in the lower central area. Methods. All positron emission tomography (PET) clinical activation studies performed over a 3-year period at the Montreal Neurological Institute and Hospital were evaluated by coregistering the PET images with three-dimensional reconstructions of magnetic resonance images obtained in the same patients. In addition to stereotactic coordinates and measurements based on distance from the sylvian fissure, gyral and sulcal landmarks were analyzed to determine their reliability in localizing the sensory areas of the tongue and lower face. The convolutional anatomy of the central area is an important guide to the identification of function. The sensory area of the tongue is recognized as a triangular region at the base of the postcentral gyrus; the sensory area of the lower face resides in the narrowed portion of the postcentral gyrus, immediately above the tongue area. Conclusions. Cortical landmarks such as the substrata of tongue and face sensory impressions are more reliable guides than stereotactic coordinates or measurements for localizing function.

Measurement of brain tissue oxygenation performed using positron emission tomography scanning to validate a novel monitoring method

2002 ◽  
Vol 96 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Arun K. Gupta ◽  
Peter J. Hutchinson ◽  
Tim Fryer ◽  
Pippa G. Al-Rawi ◽  
Dot A. Parry ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Injury ◽  
Brain Tissue ◽  
Tissue Oxygenation ◽  
Emission Tomography ◽  
Brain Tissue Oxygenation ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scans ◽  
Fine Print

Object. The benefits of measuring cerebral oxygenation in patients with brain injury are well accepted; however, jugular bulb oximetry, which is currently the most popular monitoring technique used has several shortcomings. The goal of this study was to validate the use of a new multiparameter sensor that measures brain tissue oxygenation and metabolism (Neurotrend) by comparing it with positron emission tomography (PET) scanning. Methods. A Neurotrend sensor was inserted into the frontal region of the brain in 19 patients admitted to the neurointensive care unit. After a period of stabilization, the patients were transferred to the PET scanner suite where C15O, 15O2, and H215O PET scans were obtained to facilitate calculation of regional cerebral blood volume, O2 metabolism, blood flow, and O2 extraction fraction (OEF). Patients were given hyperventilation therapy to decrease arterial CO2 by approximately 1 kPa (7.5 mm Hg) and the same sequence of PET scans was repeated. For each scanning sequence, end-capillary O2 tension (PvO2) was calculated from the OEF and compared with the reading of brain tissue O2 pressure (PbO2) provided by the sensor. In three patients the sensor was inserted into areas of contusion and these patients were eliminated from the analysis. In the subset of 16 patients in whom the sensor was placed in healthy brain, no correlation was found between the absolute values of PbO2 and PvO2 (r = 0.2, p = 0.29); however a significant correlation was obtained between the change in PbO2 (ΔPbO2) and the change in PvO2 (ΔPvO2) produced by hyperventilation in a 20-mm region of interest around the sensor (ρ = 0.78, p = 0.0035). Conclusions. The lack of correlation between the absolute values of PbO2 and PvO2 indicates that PbO2 cannot be used as a substitute for PvO2. Nevertheless, the positive correlation between ΔPbO2 and ΔPvO2 when the sensor had been inserted into healthy brain suggests that tissue PO2 monitoring may provide a useful tool to assess the effect of therapeutic interventions in brain injury.

Use of 18F-choline and 11C-choline as contrast agents in positron emission tomography imaging—guided stereotactic biopsy sampling of gliomas

2003 ◽  
Vol 99 (3) ◽  
pp. 474-479 ◽  
Author(s):  
Toshihiko Hara ◽  
Tatsuya Kondo ◽  
Tetsuo Hara ◽  
Noboru Kosaka
Keyword(s):  
Positron Emission Tomography ◽  
Contrast Agents ◽  
Anaplastic Astrocytoma ◽  
Stereotactic Biopsy ◽  
Emission Tomography ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Pet Scans ◽  
Fine Print

Object. Neuroimaging-guided stereotactic biopsy procedures are commonly used for diagnosis of gliomas. A number of the imaging modalities currently in use are not reliable enough in depicting these tumors. The authors developed 18F-choline and 11C-choline as tumor imaging agents for positron emission tomography (PET) scanning, and used them to visualize gliomas prior to stereotactic biopsy procedures. Methods. The PET studies were performed in 12 patients who were thought to be affected by gliomas observed on computerized tomography and magnetic resonance images. The 18F- and 11C-choline were injected separately, and the PET scanning was started 5 and 20 minutes postinjection. The PET scans gave quantitative information about the distribution of 18F- and 11C-choline in the brain. The tumor uptake was constant between 5 and 20 minutes with both agents. Stereotactic biopsy sampling was performed to obtain tissues from the most radioactive areas on the PET scan; histological diagnoses were made using these tissues. The results were as follows: oligodendroglioma was found in two patients, astrocytoma in one, anaplastic astrocytoma in two, and glioblastoma in seven. Conclusions. The uptake of contrast agents was always low in low-grade gliomas, and the uptake in high-grade glioma was always high. The tumor/normal (T/N) ratio of 18F-choline was 10.5:12 in anaplastic astrocytoma and 13.2:21 in glioblastoma. The 18F-choline yielded slightly superior results compared with 11C-choline with regard to the T/N ratio. In one case of oligodendroglioma the tumor showed no uptake of 18F- and 11C-choline. With this exception, the PET scans of gliomas in which 18F- and 11C-choline contrast agents were added would guide the approach to the most malignant areas for stereotactic biopsy sampling.

Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 90-92 ◽  
Author(s):  
Mark E. Linskey
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Three Dimensional ◽  
Late Recurrence ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Content Type ◽  
Single Fraction ◽  
Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

The integration of metabolic imaging in stereotactic procedures including radiosurgery: a review

2002 ◽  
Vol 97 ◽  
pp. 542-550 ◽  
Author(s):  
Marc Levivier ◽  
David Wikler ◽  
Nicolas Massager ◽  
Philippe David ◽  
Daniel Devriendt ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Tumors ◽  
Treatment Planning ◽  
Target Volume ◽  
Emission Tomography ◽  
Low Grade ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Fine Print

Object. The authors review their experience with the clinical development and routine use of positron emission tomography (PET) during stereotactic procedures, including the use of PET-guided gamma knife radiosurgery (GKS). Methods. Techniques have been developed for the routine use of stereotactic PET, and accumulated experience using PET-guided stereotactic procedures over the past 10 years includes more than 150 stereotactic biopsies, 43 neuronavigation procedures, and 34 cases treated with GKS. Positron emission tomography—guided GKS was performed in 24 patients with primary brain tumors (four pilocytic astrocytomas, five low-grade astrocytomas or oligodendrogliomas, seven anaplastic astrocytomas or ependymomas, five glioblastomas, and three neurocytomas), five patients with metastases (single or multiple lesions), and five patients with pituitary adenomas. Conclusions. Data obtained with PET scanning can be integrated with GKS treatment planning, enabling access to metabolic information with high spatial accuracy. Positron emission tomography data can be successfully combined with magnetic resonance imaging data to provide specific information for defining the target volume for the radiosurgical treatment in patients with recurrent brain tumors, such as glioma, metastasis, and pituitary adenoma. This approach is particularly useful for optimizing target selection for infiltrating or ill-defined brain lesions. The use of PET scanning contributed data in 31 cases (93%) and information that was specifically utilized to adapt the target volume in 25 cases (74%). It would seem that the integration of PET data into GKS treatment planning may represent an important step toward further developments in radiosurgery: this approach provides additional information that may open new perspectives for the optimization of the treatment of brain tumors.

Biomechanical characteristics of C1–2 cable fixations

1996 ◽  
Vol 85 (2) ◽  
pp. 316-322 ◽  
Author(s):  
Curtis A. Dickman ◽  
Neil R. Crawford ◽  
Christopher G. Paramore
Keyword(s):  
Cyclic Loading ◽  
Translational Motion ◽  
Biomechanical Testing ◽  
Three Dimensional ◽  
Constrained Motion ◽  
Content Type ◽  
Physiological Range ◽  
Fixation Techniques ◽  
Cable Fixation ◽  
Fine Print

✓ The biomechanical characteristics of four different methods of C1–2 cable fixation were studied to assess the effectiveness of each technique in restoring atlantoaxial stability. Biomechanical testing was performed on the upper cervical spines of four human cadaveric specimens. Physiological range loading was applied to the atlantoaxial specimens and three-dimensional motion was analyzed with stereophotogrammetry. The load–deformation relationships and kinematics were measured, including the stiffness, the angular ranges of motion, the linear ranges of motion, and the axes of rotation. Specimens were nondestructively tested in the intact state, after surgical destabilization, and after each of four different methods of cable fixation. Cable fixation techniques included the interspinous technique, the Brooks technique, and two variants of the Gallie technique. All specimens were tested immediately after fixation and again after the specimen was fatigued with 6000 cycles of physiological range torsional loading. All four cable fixation methods were moderately flexible immediately; the different cable fixations allowed between 5° and 40° of rotational motion and between 0.6 and 7 mm of translational motion to occur at C1–2. The Brooks and interspinous methods controlled C1–2 motion significantly better than both of the Gallie techniques. The motion allowed by one of the Gallie techniques did not differ significantly from the motion of the unfixed destabilized specimens. All cable fixation techniques loosened after cyclic loading and demonstrated significant increases in C1–2 rotational and translational motions. The bone grafts shifted during cyclic loading, which reduced the effectiveness of the fixation. The locations of the axes of rotation, which were unconstrained and mobile in the destabilized specimens, became altered with cable fixation. The C1–2 cables constrained motion by shifting the axes of rotation so that C-1 rotated around the fixed cable and graft site. After the specimen was fatigued, the axes of rotation became more widely dispersed but were usually still localized near the cable and graft site. Adequate healing requires satisfactory control of C1–2 motion. Therefore, some adjunctive fixation is advocated to supplement the control of motion after C1–2 cable fixation (that is, a cervical collar, a halo brace, or rigid internal fixation with transarticular screws).

Intraoperative angiography in the resection of arteriovenous malformations

1994 ◽  
Vol 80 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Shigetaka Anegawa ◽  
Takashi Hayashi ◽  
Ryuichiro Torigoe ◽  
Katsuhiko Harada ◽  
Shun-ichi Kihara
Keyword(s):  
Surgical Resection ◽  
Arteriovenous Malformations ◽  
Three Dimensional ◽  
Initial Operation ◽  
Total Resection ◽  
Intraoperative Angiography ◽  
Content Type ◽  
Fine Print

✓ Surgical resection of 13 operatively obscure arteriovenous malformations (AVM's) was accomplished with the assistance of intraoperative angiography, which was performed stereographically to provide three-dimensional orientation and was repeated until total resection of the AVM was confirmed. All films obtained were subtracted to improve clarity. The method presented here may be useful for the resection of all types of AVM. Only two patients had residual AVM after the initial operation. No complications attributable to angiography were noted.

Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (±)-N,N′-propylenedinicotinamide: a positron emission tomography study in rats

2000 ◽  
Vol 92 (6) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seiji Yamamoto ◽  
Weiyu Teng ◽  
Shigeru Nishizawa ◽  
Takeharu Kakiuchi ◽  
Hideo Tsukada
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Emission Tomography ◽  
Radical Scavenger ◽  
Content Type ◽  
Prophylactic Administration ◽  
Positron Emission ◽  
Hydroxyl Radical Scavenger ◽  
Fine Print

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.

A positron emission tomography study of cerebrovascular reserve before and after shunt surgery in patients with idiopathic chronic hydrocephalus

1999 ◽  
Vol 91 (4) ◽  
pp. 605-609 ◽  
Author(s):  
Petra M. Klinge ◽  
Georg Berding ◽  
Thomas Brinker ◽  
Wolfram H. Knapp ◽  
Madjid Samii
Keyword(s):  
Positron Emission Tomography ◽  
Emission Tomography ◽  
Chronic Hydrocephalus ◽  
Content Type ◽  
Cerebrovascular Reserve ◽  
Shunt Placement ◽  
Positron Emission ◽  
Group A ◽  
Group B ◽  
Fine Print

Object. In this study the authors use positron emission tomography (PET) to investigate cerebral blood flow (CBF) and cerebrovascular reserve (CVR) in chronic hydrocephalus.Methods. Ten patients whose mean age was 67 ± 10 years (mean ± standard deviation [SD]) were compared with 10 healthy volunteers who were 25 ± 3 years of age. Global CBF and CVR were determined using 15O—H2O and PET prior to shunt placement and 7 days and 7 months thereafter. The CVR was measured using 1 g acetazolamide. Neurological status was assessed based on a score assigned according to the methods of Stein and Langfitt.Seven months after shunt placement, five patients showed clinical improvement (Group A) and five did not (Group B). The average global CBF before shunt deployment was significantly reduced in comparison with the control group (40 ± 8 compared with 61 ± 7 ml/100 ml/minute; mean ± SD, p < 0.01). In Group A the CBF values were significantly lower than in Group B (36 ± 7 compared with 44 ± 8 ml/100 ml/minute; p < 0.05). The CVR before surgery, however, was not significantly different between groups (Group A = 43 ± 21%, Group B = 37 ± 29%). After shunt placement, there was an increase in the CVR in Group A to 52 ± 37% after 7 days and to 68 ± 47% after 7 months (p < 0.05), whereas in Group B the CVR decreased to 14 ± 18% (p < 0.05) after 7 days and returned to the preoperative level (39 ± 6%) 7 months after shunt placement.Conclusions. The preliminary results indicate that a reduced baseline CBF before surgery does not indicate a poor prognosis. Baseline CBF before shunt placement and preoperative CVR are not predictive of clinical outcome. A decrease in the CVR early after shunt placement, however, is related to poor late clinical outcome, whereas early improvement in the CVR after shunt placement indicates a good prognosis.

Fluorine-18—labeled fluorodeoxyglucose—positron emission tomography studies of acute brainstem Lyme neutoborreliosis

2005 ◽  
Vol 102 (5) ◽  
pp. 927-929 ◽  
Author(s):  
Michail Plotkin ◽  
Hubertus Hautzel ◽  
Bernd Joachim Krause ◽  
Stephan Mohr ◽  
Karl Josef Langen ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Magnetic Resonance Images ◽  
Emission Tomography ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Brainstem Tumor ◽  
Content Type ◽  
Positron Emission ◽  
Fluorodeoxyglucose Positron Emission ◽  
Fine Print

✓ The authors report on a patient suffering from acute Lyme borreliosis who underwent two consecutive [18F]fluorodeoxyglucose—positron emission tomography (FDG-PET) studies demonstrating the course of the disease. The first FDG-PET study revealed markedly increased glucose metabolism in the brainstem, matching exactly the signal abnormalities exhibited on magnetic resonance images and indicating a brainstem tumor. A second PET scan demonstrated no abnormality in this region, thus reflecting clinical remission following antibiotic therapy. Data in the present case indicate that hypermetabolic findings on FDG-PET studies in the brainstem region should be regarded with caution and that neuroborreliosis must be considered as a possible differential diagnosis.

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