Ictal and interictal MEG in pediatric patients with tuberous sclerosis and drug resistant epilepsy (original) (raw)
Related papers
Clinical Neurophysiology, 2008
Objective: The epilepsies associated with the tuberous sclerosis complex (TSC) are very often refractory to medical therapy. Surgery for epilepsy is an effective alternative when the critical link between the localization of seizure onset in the scalp and a particular cortical tuber can be established. In this study we perform analysis of ictal and interictal EEG to improve such link. Methods: The ictal and interictal recordings of four patients with TSC undergoing surgery for epilepsy were submitted to independent component analysis (ICA), followed by source analysis, using the sLORETA algorithm. The localizations obtained for the ictal EEG and for the average interictal spikes were compared. Results: The ICA of ictal EEG produced consistent results in different events, and there was good agreement with the tubers that were successfully removed in three of the four patients (one patient refused surgery). In some patients there was a large discrepancy between the localization of ictal and interictal sources. The interictal activity produced more widespread source localizations. Conclusions: The use of ICA of ictal EEG followed by the use of source analysis methods in four cases of epilepsy and TSC was able to localize the epileptic generators very near the lesions successfully removed in surgery for epilepsy. Significance: The ICA of ictal EEG events may be a useful add-on to the tools used to establish the connection between epileptic scalp activity and the cortical tubers originating it, in patients with TSC considered for surgery of epilepsy.
Magnetic source imaging localizes epileptogenic zone in children with tuberous sclerosis complex
Neurology, 2006
The authors assessed whether magnetoencephalography/magnetic source imaging (MEG/MSI) identified epileptogenic zones in patients with tuberous sclerosis complex (TSC). In six TSC children with focal seizures, ictal video-EEG predicted the region of resection with 56% sensitivity, 80% specificity, and 77% accuracy (p ϭ 0.02), whereas interictal MEG/MSI fared better (100%, 94%, and 95%, respectively; p Ͻ 0.0001). Interictal MEG/MSI seems to identify epileptogenic zones more accurately in children with TSC and focal intractable epilepsy.
DTI of tuber and perituberal tissue can predict epileptogenicity in tuberous sclerosis complex
Neurology, 2015
To evaluate whether diffusion tensor imaging (DTI) can predict epileptogenic tubers by measuring apparent diffusion coefficient (ADC), fractional anisotropy, axial diffusivity, and radial diffusivity in both tubers and perituberal tissue in pediatric patients with tuberous sclerosis complex (TSC) undergoing epilepsy surgery. We retrospectively selected 23 consecutive patients (aged 0.4-19.6 years, mean age of 5.2; 13 female, 10 male) who underwent presurgical DTI and subsequent surgical resection between 2004 and 2013 from the University of California-Los Angeles TSC Clinic. We evaluated presurgical examinations including video-EEG, brain MRI, (18)F-fluorodeoxyglucose-PET, magnetic source imaging, and intraoperative electrocorticography for determining epileptogenic tubers. A total of 545 tubers, 33 epileptogenic and 512 nonepileptogenic, were identified. Two observers generated the regions of interest (ROIs) of tubers (ROI(tuber)), the 4-mm-thick ring-shaped ROIs surrounding the tu...
Local epileptogenic networks in tuberous sclerosis complex: A case review
Epilepsy & Behavior, 2007
Objective. Cortical tubers are a pathognomonic finding in some patients with tuberous sclerosis complex (TSC), and are believed to be epileptogenic foci. Surgery is an effective option in selected patients with TSC who are refractory to medical therapy. This article describes three patients with TSC who underwent three-stage epilepsy surgery at our center, with the intention of examining local electrophysiological changes after each stage of the procedure.
Noninvasive testing, early surgery, and seizure freedom in tuberous sclerosis complex
Neurology, 2010
The unambiguous identification of the epileptogenic tubers in individuals with tuberous sclerosis complex (TSC) can be challenging. We assessed whether magnetic source imaging (MSI) and coregistration of 18 fluorodeoxyglucose PET (FDG-PET) with MRI could improve the identification of the epileptogenic regions noninvasively in children with TSC.
Localization of the Epileptogenic Foci in Tuberous Sclerosis Complex: A Pediatric Case Report
Frontiers in Human Neuroscience, 2014
Tuberous sclerosis complex (TSC) is a rare disorder of tissue growth and differentiation, characterized by benign hamartomas in the brain and other organs. Up to 90% of TSC patients develop epilepsy and 50% become medically intractable requiring resective surgery.The surgical outcome ofTSC patients depends on the accurate identification of the epileptogenic zone consisting of tubers and the surrounding epileptogenic tissue. There is conflicting evidence whether the epileptogenic zone is in the tuber itself or in abnormally developed surrounding cortex. Here, we report the localization of the epileptiform activity among the many cortical tubers in a 4-year-old patient with TSC-related refractory epilepsy undergoing magnetoencephalography (MEG), electroencephalography (EEG), and diffusion tensor imaging (DTI). For MEG, we used a prototype system that offers higher spatial resolution and sensitivity compared to the conventional adult systems. The generators of interictal activity were localized using both EEG and MEG with equivalent current dipole (ECD) and minimum norm estimation (MNE) methods according to the current clinical standards. For DTI, we calculated four diffusion scalar parameters for the fibers passing through four ROIs defined: (i) at a large cortical tuber identified at the right quadrant, (ii) at the normal appearing tissue contralateral to the tuber, (iii) at the cluster formed by ECDs fitted at the peak of interictal spikes, and (iv) at the normal appearing tissue contralateral to the cluster. ECDs were consistently clustered at the vicinity of the large calcified cortical tuber. MNE and ECDs indicated epileptiform activity in the same areas. DTI analysis showed differences between the scalar values of the tracks passing through the tuber and the ECD cluster. In this illustrative case, we provide evidence from different neuroimaging modalities, which support the view that epileptiform activity may derive from abnormally developed tissue surrounding the tuber rather than the tuber itself.
Are cortical tubers epileptogenic? Evidence from electrocorticography
Epilepsia, 2009
The purpose of this study was to characterize the epileptogenicity of tubers and surrounding cortex in patients with tuberous sclerosis complex (TSC). Three pediatric patients with TSC and intractable epilepsy underwent surgical resection of tubers associated with epileptogenic foci. In all patients, presurgical imaging revealed a prominent tuber that correlated on electroencephalography (EEG) with frequent interictal epileptiform discharges and electrographic seizures. Intracranial electrocorticography (ECoG) was performed using subdural grids placed over the tuber and surrounding cortex and depth electrodes positioned directly within the tuber. In all three patients, the depth electrode within the tuber was electrographically silent, whereas the surrounding cortical tissue showed significant epileptiform activity. The tuber and the electrically active adjacent cortex were resected. The patients experienced a drastic reduction in seizure frequency postsurgery. Epileptogenicity of cortical tubers may derive not from the lesion itself, but rather from the perturbation or abnormal development of the surrounding cortex.
Topographical Distribution of Epileptogenic Tubers in Patients With Tuberous Sclerosis Complex
Journal of child neurology, 2015
Tuberous sclerosis complex is a multisystem genetic syndrome often affecting the central nervous system. The purpose of the current study was to identify topographical patterns in the distribution specific to epileptogenic (n = 37) and nonepileptogenic (n = 544) tubers throughout the brain for a cohort of 23 tuberous sclerosis complex patients with a history of seizures. Tubers localized to the inferior parietal lobes, middle frontal lobes, middle temporal lobes, or central sulcus regions were associated with a high frequency of epileptogenic tubers. Epileptogenic tubers occurred statistically more frequently within the inferior parietal lobe and within the central sulcus region in children younger than 1 or between 1 and 3 years old, respectively. Results imply seizure activity in tuberous sclerosis complex patients can be associated with the location of cortical tubers.
Localizing value of ictal MEG in neocortical epilepsy
Biomag, 2002
While MEG mapping of interictal spikes has been found to be useful for presurgical localization of epileptic foci , seizures have rarely been captured in MEG recordings. We have recorded seizures by MEG in 8 patients, 7 to 47 years old, with intractable localization-related epilepsy of presumed neocortical origin. Four of the eight have had resective surgery. Prior to surgery each of the four patients was averaging up to 6-40 seizures per day. Ictal MEG localizations were confirmed by subsequent intracranial EEG monitoring. One patient had a left frontotemporal lobe resection, one had a left temporoparietal resection sparing part of the epileptic focus, which was in language cortex, one had a left paracentral lobule resection, and one had a right frontal operculum resection. All four have had a dramatic improvement in seizures with simple partial seizures but no complex partial or secondarily generalized seizures in two, and only two seizures in the past year in the third. The fourth patient has not had a seizure in the 4 months since her surgery. Two of the four other patients are scheduled for intracranial monitoring, and the third has declined surgery. The fourth had simple partial seizures arising from the primary motor cortex and has had a subdural electrode array implanted for chronic direct neocortical stimulation with subsequent reduction in seizures. Ictal MEG in these patients has accurately predicted the site of ictal onset in those who have had intracranial monitoring. Resection of the MEG ictal zone has been associated with good surgical outcome in those patients. Ictal MEG is useful in determining the site of implantation of intracranial electrodes. Ictal MEG and concordant noninvasive diagnostic studies may some day replace intracranial EEG monitoring in selective patients with neocortical lesions.