scholarly journals Integration of functional neuronavigation and intraoperative MRI in surgery for drug-resistant extratemporal epilepsy close to eloquent brain areas

2013 ◽  
Vol 34 (4) ◽  
pp. E4 ◽  
Author(s):  
Björn Sommer ◽  
Peter Grummich ◽  
Roland Coras ◽  
Burkhard Sebastian Kasper ◽  
Ingmar Blumcke ◽  
...  

Object The authors performed a retrospective study to assess the impact of functional neuronavigation and intraoperative MRI (iMRI) on surgery of extratemporal epileptogenic lesions on postsurgical morbidity and seizure control. Methods Twenty-five patients (14 females and 11 males) underwent extratemporal resections for drug-resistant epilepsy close to speech/motor brain areas or adjacent to white matter tracts. The mean age at surgery was 34 years (range 12–67 years). The preoperative mean disease duration was 13.2 years. To avoid awake craniotomy, cortical motor-sensory representation was mapped during preoperative evaluation in 14 patients and speech representation was mapped in 15 patients using functional MRI. In addition, visualization of the pyramidal tract was performed in 11 patients, of the arcuate fascicle in 7 patients, and of the visual tract in 6 patients using diffusion tensor imaging. The mean minimum distance of tailored resection between the eloquent brain areas was 5.6 mm. During surgery, blood oxygen level–dependent imaging and diffusion tensor imaging data were integrated into neuronavigation and displayed through the operating microscope. The postoperative mean follow-up was 44.2 months. Results In 20% of these patients, further intraoperative resection was performed because of intraoperatively documented residual lesions according to iMRI findings. At the end of resection, the final iMRI scans confirmed achievement of total resection of the putative epileptogenic lesion in all patients. Postoperatively, transient complications and permanent complications were observed in 20% and 12% of patients, respectively. Favorable postoperative seizure control (Engel Classes I and II) was achieved in 84% and seizure freedom in 72% of these consecutive surgical patients. Conclusions By using functional neuronavigation and iMRI for treatment of epileptogenic brain lesions, the authors achieved a maximum extent of resection despite the lesions' proximity to eloquent brain cortex and fiber tracts in all cases. The authors' results underline possible benefits of this technique leading to a favorable seizure outcome with acceptable neurological deficit rates in difficult-to-treat extratemporal epilepsy.

Author(s):  
A Hadjinicolaou ◽  
P Jain ◽  
I Yau ◽  
R Whitney ◽  
JT Rutka ◽  
...  

Background: We aimed to study the proportion of patients with DRE and pre-existing VNS device, who show improvement of at least one class in McHugh seizure outcome classification at last follow up after generator replacement with cardiac based VNS device. Methods: We retrospectively reviewed children with DRE with the older VNS model (102) who underwent battery replacement with the AspireSR®, model 106 since September 2016 at our institution. We assessed the seizure outcomes since the first VNS device insertion till the last follow up after AspireSR® (with cardiac-based seizure detection) using McHugh seizure outcome classification. Results: The study population was comprised of 15 patients. The mean age at seizure onset was 2.7 years old, with mean age of initial VNS1 placement being 10.1 years and mean age of replacement with VNS2 being 14.9 years of age. Three of the fifteen patients had reported status epilepticus prior to initial VNS insertion, and none reported episodes following insertion. Two patients showed at least one class improvement in McHugh seizure outcomes at last follow up after VNS2. Conclusions: Through our preliminary data at the present time, we note that the majority of our patients maintains their seizure control following replacement with VNS2 with a few showing improvement.


Author(s):  
Shawn D’Souza ◽  
Lisa Hirt ◽  
David R Ormond ◽  
John A Thompson

Abstract Gliomas are neoplasms that arise from glial cell origin and represent the largest fraction of primary malignant brain tumours (77%). These highly infiltrative malignant cell clusters modify brain structure and function through expansion, invasion and intratumoral modification. Depending on the growth rate of the tumour, location and degree of expansion, functional reorganization may not lead to overt changes in behaviour despite significant cerebral adaptation. Studies in simulated lesion models and in patients with stroke reveal both local and distal functional disturbances, using measures of anatomical brain networks. Investigations over the last two decades have sought to use diffusion tensor imaging tractography data in the context of intracranial tumours to improve surgical planning, intraoperative functional localization, and post-operative interpretation of functional change. In this study, we used diffusion tensor imaging tractography to assess the impact of tumour location on the white matter structural network. To better understand how various lobe localized gliomas impact the topology underlying efficiency of information transfer between brain regions, we identified the major alterations in brain network connectivity patterns between the ipsilesional versus contralesional hemispheres in patients with gliomas localized to the frontal, parietal or temporal lobe. Results were indicative of altered network efficiency and the role of specific brain regions unique to different lobe localized gliomas. This work draws attention to connections and brain regions which have shared structural susceptibility in frontal, parietal and temporal lobe glioma cases. This study also provides a preliminary anatomical basis for understanding which affected white matter pathways may contribute to preoperative patient symptomology.


2021 ◽  
Author(s):  
Weihong Yuan ◽  
Jonathan Dudley ◽  
Alexis B Slutsky-Ganesh ◽  
James Leach ◽  
Pete Scheifele ◽  
...  

ABSTRACT Introduction Special Weapons and Tactics (SWAT) personnel who practice breaching with blast exposure are at risk for blast-related head trauma. We aimed to investigate the impact of low-level blast exposure on underlying white matter (WM) microstructure based on diffusion tensor imaging (DTI) and neurite orientation and density imaging (NODDI) in SWAT personnel before and after breacher training. Diffusion tensor imaging is an advanced MRI technique sensitive to underlying WM alterations. NODDI is a novel MRI technique emerged recently that acquires diffusion weighted data from multiple shells modeling for different compartments in the microstructural environment in the brain. We also aimed to evaluate the effect of a jugular vein compression collar device in mitigating the alteration of the diffusion properties in the WM as well as its role as a moderator on the association between the diffusion property changes and the blast exposure. Materials and Methods Twenty-one SWAT personnel (10 non-collar and 11 collar) completed the breacher training and underwent MRI at both baseline and after blast exposure. Diffusion weighted data were acquired with two shells (b = 1,000, 2,000 s/mm2) on 3T Phillips scanners. Diffusion tensor imaging metrices, including fractional anisotropy, mean, axial, and radial diffusivity, and NODDI metrics, including neurite density index (NDI), isotropic volume fraction (fiso), and orientation dispersion index, were calculated. Tract-based spatial statistics was used in the voxel-wise statistical analysis. Post hoc analyses were performed for the quantification of the pre- to post-blast exposure diffusion percentage change in the WM regions with significant group difference and for the assessment of the interaction of the relationship between blast exposure and diffusion alteration. Results The non-collar group exhibited significant pre- to post-blast increase in NDI (corrected P < .05) in the WM involving the right internal capsule, the right posterior corona radiation, the right posterior thalamic radiation, and the right sagittal stratum. A subset of these regions showed significantly greater alteration in NDI and fiso in the non-collar group when compared with those in the collar group (corrected P < .05). In addition, collar wearing exhibited a significant moderating effect for the alteration of fiso for its association with average peak pulse pressure. Conclusions Our data provided initial evidence of the impact of blast exposure on WM diffusion alteration based on both DTI and NODDI. The mitigating effect of WM diffusivity changes and the moderating effect of collar wearing suggest that the device may serve as a promising solution to protect WM against blast exposure.


2015 ◽  
Vol 105 ◽  
pp. 20-28 ◽  
Author(s):  
Linda Isaac ◽  
Keith L. Main ◽  
Salil Soman ◽  
Ian H. Gotlib ◽  
Ansgar J. Furst ◽  
...  

2015 ◽  
Vol 38 (1) ◽  
pp. E5 ◽  
Author(s):  
Björn Sommer ◽  
Cornelia Wimmer ◽  
Roland Coras ◽  
Ingmar Blumcke ◽  
Bogdan Lorber ◽  
...  

OBJECT Cerebral gangliogliomas (GGs) are highly associated with intractable epilepsy. Incomplete resection due to proximity to eloquent brain regions or misinterpretation of the resection amount is a strong negative predictor for local tumor recurrence and persisting seizures. A potential method for dealing with this obstacle could be the application of intraoperative high-field MRI (iopMRI) combined with neuronavigation. METHODS Sixty-nine patients (31 female, 38 male; median age 28.5 ± 15.4 years) suffering from cerebral GGs were included in this retrospective study. Five patients received surgery twice in the observation period. In 48 of the 69 patients, 1.5-T iopMRI combined with neuronavigational guidance was used. Lesions close to eloquent brain areas were resected with the implementation of preoperative diffusion tensor imaging tractography and blood oxygenation level–dependent functional MRI (15 patients). RESULTS Overall, complete resection was accomplished in 60 of 69 surgical procedures (87%). Two patients underwent biopsy only, and in 7 patients, subtotal resection was accomplished because of proximity to critical brain areas. Excluding the 2 biopsies, complete resection using neuronavigation/iopMRI was documented in 33 of 46 cases (72%) by intraoperative imaging. Remnant tumor mass was identified intraoperatively in 13 of 46 patients (28%). After intraoperative second-look surgery, the authors improved the total resection rate by 9 patients (up to 91% [42 of 46]). Of 21 patients undergoing conventional surgery, 14 (67%) had complete resection without the use of iopMRI. Regarding epilepsy outcome, 42 of 60 patients with seizures (70%) became completely seizure free (Engel Class IA) after a median follow-up time of 55.5 ± 36.2 months. Neurological deficits were found temporarily in 1 (1.4%) patient and permanently in 4 (5.8%) patients. CONCLUSIONS Using iopMRI combined with neuronavigation in cerebral GG surgery, the authors raised the rate of complete resection in this series by 19%. Given the fact that total resection is a strong predictor of long-term seizure control, this technique may contribute to improved seizure outcome and reduced neurological morbidity.


2021 ◽  
pp. 028418512110582
Author(s):  
Takumi Yokohama ◽  
Motoyuki Iwasaki ◽  
Daisuke Oura ◽  
Sho Furuya ◽  
Yoshimasa Niiya

Background Recent studies have indicated that injuries such as muscle tears modify the microstructural integrity of muscle, leading to substantial alterations in measured diffusion parameters. Therefore, the fractional anisotropy (FA) value decreases. However, we hypothesized that soft tissue, such as muscle tissue, undergoes reversible changes under conditions of compression without fiber injury. Purpose To evaluate the FA change due to compression in muscle tissue without fiber injury. Material and Methods Diffusion tensor imaging (DTI) was performed on both feet of 10 healthy volunteers (mean age = 35.0 ± 10.39 years; age range = 23–52 years) using a 3.0-T magnetic resonance imaging (MRI) scanner with an eight-channel phased array knee coil. An MRI-compatible sphygmomanometer was applied to the individuals’ lower legs and individuals were placed in a compressed state. Then, rest intervals of 5 min were set in re-rest state after compression. The FA value, apparent diffusion coefficient (ADC), and eigenvalues (λ1, λ2, λ3) of the gastrocnemius and soleus muscle were measured at each state. Results The mean FA values increased in all muscles in a compressed state, while the mean λ3 decreased. In all muscles, significant differences were found between the rest and compressed states in terms of mean FA and λ3 ( P < 0.0001). Conclusion We confirmed the reversibility of the DTI metrics, which suggests that there was no muscle injury during this study. In cases of compression without fiber injury, the FA value increases, because fibers are strongly aligned in the longitudinal direction.


Sign in / Sign up

Export Citation Format

Share Document