scholarly journals P.173 Evaluation of Arterial Spin Labeling (ASL) Perfusion Imaging in Poorly-Defined Focal Epilepsy in Children

2021 ◽  
Vol 48 (s3) ◽  
pp. S69-S69
Author(s):  
J Lam ◽  
P Tomaszewski ◽  
G Gilbert ◽  
JT Moreau ◽  
M Guiot ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Qualitative Analysis ◽  
Arterial Spin Labeling ◽  
Visual Inspection ◽  
Focal Epilepsy ◽  
Spin Labeling ◽  
Epileptogenic Zone ◽  
Imaging Data ◽  
Mri Evaluation

Background: Poorly-defined cases (PDCs) of focal epilepsy are cases with no/subtle MRI abnormalities or have abnormalities extending beyond the lesion visible on MRI. Here, we evaluated the utility of Arterial Spin Labeling (ASL) MRI perfusion in PDCs of pediatric focal epilepsy. Methods: ASL MRI was obtained in 25 consecutive children presenting with poorly-defined focal epilepsy (20 MRI- positive, 5 MRI-negative). Qualitative visual inspection and quantitative analysis with asymmetry and Z-score maps were used to detect perfusion abnormalities. ASL results were compared to the hypothesized epileptogenic zone (EZ) derived from other clinical/imaging data and the resection zone in patients with Engel I/II outcome and >18 month follow-up. Results: Qualitative analysis revealed perfusion abnormalities in 17/25 total cases (68%), 17/20 MRI-positive cases (85%) and none of the MRI-negative cases. Quantitative analysis confirmed all cases with abnormalities on qualitative analysis, but found 1 additional true-positive and 4 false-positives. Concordance with the surgically-proven EZ was found in 10/11 cases qualitatively (sensitivity=91%, specificity=50%), and 11/11 cases quantitatively (sensitivity=100%, specificity=23%). Conclusions: ASL perfusion may support the hypothesized EZ, but has limited localization benefit in MRI-negative cases. Nevertheless, owing to its non-invasiveness and ease of acquisition, ASL could be a useful addition to the pre-surgical MRI evaluation of pediatric focal epilepsy.

Arterial Spin Labeling is a Useful MRI Method for Presurgical Evaluation in MRI-Negative Focal Epilepsy

2021 ◽  
Author(s):  
Martin Kojan ◽  
Martin Gajdoš ◽  
Pavel Říha ◽  
Irena Doležalová ◽  
Zdeněk Řehák ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Focal Epilepsy ◽  
Spin Labeling ◽  
Presurgical Evaluation

scholarly journals The proportion of seizure onset zone contacts resected is not associated with outcome following SEEG-guided resective epilepsy surgery in children

2021 ◽  
Author(s):  
Mehdi Khan ◽  
Aswin Chari ◽  
Kiran Seunarine ◽  
Christin Eltze ◽  
Friederike Moeller ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Univariate Analysis ◽  
Seizure Outcome ◽  
Epileptogenic Zone ◽  
Imaging Data ◽  
Seizure Onset ◽  
Binary Logistic Regression Model ◽  
Primary Analysis ◽  
Seizure Onset Zone

AbstractPurposeChildren undergoing stereoelectroencephalography (SEEG)-guided epilepsy surgery represent a complex cohort. We aimed to determine whether the proportion of putative seizure onset zone (SOZ) contacts resected associates with seizure outcome in a cohort of children undergoing SEEG-guided resective epilepsy surgery.MethodsPatients who underwent SEEG-guided resective surgery over a six-year period were included. The proportion of SOZ contacts resected was determined by co-registration of pre- and post-operative imaging. Seizure outcomes were classified as seizure free (SF, Engel class I) or not seizure-free (NSF, Engel class II-IV) at last clinical follow-up.ResultsOf 94 patients undergoing SEEG, 29 underwent subsequent focal resection of whom 22 had sufficient imaging data to be included in the primary analysis (median age at surgery of 10 years, range 5-18). Fifteen (68.2%) were SF and 7 (31.8%) NSF at median follow-up of 19.5 months (range 12-46). On univariate analysis, histopathology, was the only significant factor associated with SF (p<0.05). The percentage of defined SOZ contacts resected ranged from 25-100% and was not associated with SF (p=0.89). In a binary logistic regression model, it was highly likely that histology was the only independent predictor of outcome, although the interpretation was limited by pseudo-complete separation of the data.ConclusionHistopathology is a significant predictor of surgical outcomes in children undergoing SEEG-guided resective epilepsy surgery. The percentage of SOZ contacts resected was not associated with SF. Factors such as spatial organisation of the epileptogenic zone, neurophysiological biomarkers and the prospective identification of pathological tissue may therefore play an important role.

scholarly journals Stereotactic laser ablation for nonlesional cingulate epilepsy: case report

2018 ◽  
Vol 22 (5) ◽  
pp. 481-488 ◽  
Author(s):  
Ahmad Marashly ◽  
Michelle M. Loman ◽  
Sean M. Lew
Keyword(s):  
Laser Ablation ◽  
Right Hemisphere ◽  
Focal Epilepsy ◽  
Mesial Temporal Lobe Epilepsy ◽  
Epileptogenic Zone ◽  
Seizure Onset Zone ◽  
The Right ◽  
Invasive Evaluation ◽  
Motor Areas

Stereotactic laser ablation (SLA) is being increasingly used to treat refractory focal epilepsy, especially mesial temporal lobe epilepsy. However, emerging evidence suggests it can be used for extratemporal lobe epilepsy as well.The authors report the case of a 17-year-old male who presented with refractory nocturnal seizures characterized by bilateral arms stiffening or rhythmic jerking lasting several seconds. Semiology suggested an epileptogenic zone close to one of the supplementary sensory motor areas. Electroencephalography showed seizures arising from the central region without consistent lateralization. Brain imaging showed no abnormality. An invasive evaluation using bilateral stereoelectroencephalography (SEEG) was utilized in 2 steps, first to establish the laterality of seizures, and second to further cover the mesial cingulate region of the right hemisphere. Seizures arose from the middle portion of the right cingulate gyrus. Extraoperative electrical mapping revealed that the seizure onset zone was adjacent to eloquent motor areas. SLA targeting the right midcingulate gyrus was performed. The patient has remained seizure free since immediately after the procedure with no postoperative deficits (follow-up of 17 months).This case highlights the utility of SEEG in evaluating difficult-to-localize, focal epilepsy. It also demonstrates that the use of SLA can be extended to nonlesional, extratemporal epilepsies.

Stereoelectroencephalography in Children and Adolescents With Difficult-to-Localize Refractory Focal Epilepsy

Neurosurgery ◽  
2014 ◽  
Vol 75 (3) ◽  
pp. 258-268 ◽  
Author(s):  
Jorge Gonzalez-Martinez ◽  
Jeffrey Mullin ◽  
Juan Bulacio ◽  
Ajay Gupta ◽  
Rei Enatsu ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Pediatric Patients ◽  
Focal Epilepsy ◽  
Early Experience ◽  
Morbidity Rate ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Epileptogenic Zone ◽  
Eloquent Cortex

Abstract BACKGROUND: Although stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. OBJECTIVE: To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. METHODS: Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. RESULTS: Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. CONCLUSION: The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.

scholarly journals Arterial spin labeling: Adaptive thresholding for epileptogenic zone detection in MRI-negative epilepsy

2021 ◽  
Author(s):  
Martin Gajdoš ◽  
Pavel Říha ◽  
Martin Kojan ◽  
Irena Doležalová ◽  
Henk-Jan Mutsaerts ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
True Positive Rate ◽  
Spin Labeling ◽  
Asymmetry Index ◽  
Minimal Distance ◽  
Epileptogenic Zone ◽  
Mri Findings ◽  
Unaffected Side ◽  
Positive Rate ◽  
Drug Resistant Epilepsy

Abstract Drug-resistant epilepsy is a diagnostic and therapeutic challenge, mainly in patients with negative MRI findings. State-of-the-art imaging methods complement standard epilepsy protocols with new information and help to epileptologists to increase reliability of their decisions. In this study, we investigate if arterial spin labeling (ASL) perfusion MRI can help localizing the epileptogenic zone (EZ). To that end, we developed an image processing method to detect the EZ as an area with hypoperfusion relative to the contralateral unaffected side, using subject-specific thresholding of the asymmetry index in ASL images. We demonstrated three thresholding criteria (minimal product criterion, minimal distance criterion, and elbow criterion) on 29 patients with MRI-negative epilepsy (age 32.98 ± 10.4 years). The minimal product criterion showed optimal results in terms of positive predictive value (mean 0.12 and 0.22) and true positive rate (mean 0.71 and 1.82). Additionally, we found high accuracy in determining the EZ side (mean 0.86 and 0.73 out of 1.00). In conclusion, the ASL can be easily incorporated to the standard presurgical MR protocol and it provides an additional benefit in EZ localization.

scholarly journals Arterial spin labeling perfusion-weighted MRI for long-term follow-up of a cerebral arteriovenous malformation after stereotactic radiosurgery

2014 ◽  
Vol 3 (1) ◽  
pp. 204798161351016 ◽  
Author(s):  
Kazuhiro Shimizu ◽  
Nobuyuki Kosaka ◽  
Tatsuya Yamamoto ◽  
Hiroki Shioura ◽  
Toshiaki Kodera ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
High Signal ◽  
Non Invasive ◽  
Signal Abnormality ◽  
Complete Obliteration ◽  
Long Term Follow Up

We present a longitudinal series of arterial spin-labeling magnetic resonance imaging (ASL-MRI) in a patient with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS). Pretreatment ASL-MRI showed high signal intensity in both the nidus and draining veins, and the latter signal abnormality gradually moved proximally by 14 months after SRS. At 24 months, the signal abnormalities finally disappeared, indicating complete obliteration of the nidus. The hemodynamic changes in the AVM were clearly visualized in the longitudinal ASL-MRI series, thus this non-invasive MR method may be useful not only for detecting AVMs but also for assessment of their response after SRS.

Arterial spin labeling magnetic resonance imaging: toward noninvasive diagnosis and follow-up of pediatric brain arteriovenous malformations

2015 ◽  
Vol 15 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Thomas Blauwblomme ◽  
Olivier Naggara ◽  
Francis Brunelle ◽  
David Grévent ◽  
Stéphanie Puget ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Arteriovenous Malformations ◽  
Spin Labeling ◽  
Absolute Quantification ◽  
Vascular Abnormalities ◽  
Brain Arteriovenous Malformations ◽  
Brain Avm ◽  
Pediatric Brain ◽  
Normal Cortex

OBJECT Arterial spin labeling (ASL)-MRI is becoming a routinely used sequence for ischemic strokes, as it quantifies cerebral blood flow (CBF) without the need for contrast injection. As brain arteriovenous malformations (AVMs) are highflow vascular abnormalities, increased CBF can be identified inside the nidus or draining veins. The authors aimed to analyze the relevance of ASL-MRI in the diagnosis and follow-up of children with brain AVM. METHODS The authors performed a retrospective analysis of 21 patients who had undergone digital subtraction angiography (DSA) and pseudo-continuous ASL-MRI for the diagnosis or follow-up of brain AVM after radiosurgery or embolization. They compared the AVM nidus location between ASL-MRI and 3D contrast-enhanced T1 MRI, as well as the CBF values obtained in the nidus (CBFnidus) and the normal cortex (CBFcortex) before and after treatment. RESULTS The ASL-MRI correctly demonstrated the nidus location in all cases. Nidal perfusion (mean CBFnidus 137.7 ml/100 mg/min) was significantly higher than perfusion in the contralateral normal cortex (mean CBFcortex 58.6 ml/100 mg/min; p < 0.0001, Mann-Whitney test). Among 3 patients followed up after embolization, a reduction in both AVM size and CBF values was noted. Among 5 patients followed up after radiosurgery, a reduction in the nidus size was observed, whereas CBFnidus remained higher than CBFcortex. CONCLUSIONS In this study, ASL-MRI revealed nidus location and patency after treatment thanks to its ability to demonstrate focal increased CBF values. Absolute quantification of CBF values could be relevant in the follow-up of pediatric brain AVM after partial treatment, although this must be confirmed in larger prospective trials.

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