Ismail S. Mohamed

The utility of magnetoencephalography in the presurgical evaluation of refractory insular epilepsy.

To study the utility of magnetoencephalography (MEG) in patients with refractory insular epilepsy. Covered by highly functional temporal, frontal, and parietal opercula, insular‐onset seizures can manifest a variety of ictal symptoms falsely leading to a diagnosis of temporal, frontal, or parietal lobe seizures. Lack of recognition of insular seizures may be responsible for some epilepsy surgery failures.

Is focal cortical dysplasia sporadic? Family evidence for genetic susceptibility

Focal cortical dysplasia is a common cortical malformation and an important cause of epilepsy. There is evidence for shared molecular mechanisms underlying cortical dysplasia, ganglioglioma, hemimegalencephaly, and dysembryoplastic neuroepithelial tumor. However, there are no familial reports of typical cortical dysplasia or co‐occurrence of cortical dysplasia and related lesions within the same pedigree. We report the clinical, imaging, and histologic features of six pedigrees with familial cortical dysplasia and related lesions. Twelve patients from six pedigrees were ascertained from pediatric and adult epilepsy centers, eleven of whom underwent epilepsy surgery. Pedigree data, clinical information, neuroimaging findings, and histopathologic features are presented. The families comprise brothers with focal cortical dysplasia, a male and his sister with focal cortical dysplasia, a female with focal cortical dysplasia and her brother with hemimegalencephaly, a female with focal cortical dysplasia and her female first cousin with ganglioglioma, a female with focal cortical dysplasia and her male cousin with dysembryoplastic neuroepithelial tumor, and a female and her nephew with focal cortical dysplasia. This series shows that focal cortical dysplasia can be familial and provides clinical evidence suggesting that cortical dysplasia, hemimegalencephaly, ganglioglioma, and dysembryoplastic neuroepithelial tumors may share common genetic determinants.

Different localizations underlying cortical gelastic epilepsy: Case series and review of literature

BACKGROUND Gelastic seizures (GS) are classically observed with hypothalamic hamartomas but they can also be associated with cortical epileptogenic foci. OBJECTIVE To study the different cortical localizations associated with GS. METHODS We reviewed the data from all patients with cortical GS investigated in our epilepsy unit from 1974 to 2012 and in the literature from 1956 to 2013. RESULTS Sixteen cases were identified in our database and 77 in the literature. Investigations provided confident focus localization in 9 and 18, respectively. In our series, the identified foci were located in the mesial temporal structures (2 left, 1 right), lateral temporal cortex (1 right), superior frontal gyrus (1 left), and operculoinsular region [3 right (orbitofrontal or frontal operculum extending into the anterior insula) and 1 left (frontal operculum extending into the anterior insula)]. In the literature, the identified foci (13 right/5 left) were located in the temporal lobe of 4 (1 right inferior, 1 right medial and inferior, 1 right posterior middle, inferior extending posteriorly to the lingual gyrus, and 1 left middle, inferior, and medial), in the frontal lobe of 12 [10 (6 right/4 left) medial (i.e., superior, medial frontal, and/or anterior cingulate gyri), 1 lateral (right anterior inferior frontal gyrus), and 1 right medioposterior orbitofrontal cortex] and in the parietal lobe of 2 (1 left superior parietal lobule and 1 right parietal operculum) patients. CONCLUSION Ictal laughter is a poorly lateralizing and localizing feature as it may be encountered in patients with a focus in the left or right frontal, temporal, parietal, or insular lobe.

Does treatment have an impact on incidence and risk factors for autism spectrum disorders in children with infantile spasms

Infantile spasms (IS) are a severe form of childhood epilepsy associated with autism spectrum disorders (ASD) in up to 35% of cases. The objective of this post hoc analysis of our randomized control trial was to determine whether rapid diagnosis and treatment of IS could limit the incidence of ASD while identifying risk factors related to ASD outcome.

Magnetoencephalographic signatures of insular epileptic spikes based on functional connectivity

Failure to recognize insular cortex seizures has recently been identified as a cause of epilepsy surgeries targeting the temporal, parietal, or frontal lobe. Such failures are partly due to the fact that current noninvasive localization techniques fare poorly in recognizing insular epileptic foci. Our group recently demonstrated that magnetoencephalography (MEG) is sensitive to epileptiform spikes generated by the insula. In this study, we assessed the potential of distributed source imaging and functional connectivity analyses to distinguish insular networks underlying the generation of spikes. Nineteen patients with operculo‐insular epilepsy were investigated. Each patient underwent MEG as well as T1‐weighted magnetic resonance imaging (MRI) as part of their standard presurgical evaluation. Cortical sources of MEG spikes were reconstructed with the maximum entropy on the mean algorithm, and their time courses served to analyze source functional connectivity. The results indicate that the anterior and posterior subregions of the insula have specific patterns of functional connectivity mainly involving frontal and parietal regions, respectively. In addition, while their connectivity patterns are qualitatively similar during rest and during spikes, couplings within these networks are much stronger during spikes. These results show that MEG can establish functional connectivity‐based signatures that could help in the diagnosis of different subtypes of insular cortex epilepsy. Hum Brain Mapp 37:3250–3261, 2016.

Reflex operculoinsular seizures

Activation of specific cortical territories by certain stimuli is known to trigger focal seizures. We report three cases of well documented operculo-insular reflex seizures, triggered by somatosensory stimuli in two and loud noises in the third. Limited operculoinsular resection resulted in an excellent outcome for all. We discuss these observations in regard to the literature on reflex epilepsy and known functions of the insula. [Published with video sequences online].

Source localization of interictal spike-locked neuromagnetic oscillations in pediatric neocortical epilepsy

OBJECTIVE To evaluate the utility of an event-related beamforming (ERB) algorithm in source localization of interictal discharges. METHODS We analyzed interictal magnetoencephalography data in 35 children with intractable neocortical epilepsy. We used a spatiotemporal beamforming method to estimate the spatial distribution of source power in individual interictal spikes. We compared ERB results to source localization using the equivalent current dipole model and to the seizure onset zones on intracranial EEG. RESULTS Focal beamformer localization was observed in 66% of patients and multifocal in the remaining 34%. ERB localized within 2 cm of the equivalent current dipole cluster centroid in 77% of the patients. ERB localization was concordant with the seizure onset zone on intracranial EEG at the gyral level in 69% of patients. Focal ERB localization area was included in the resection margin in 22/23 patients. However, focal ERB localization was not statistically associated with better surgical outcome. CONCLUSIONS ERB can be used for source localization of interictal spikes and can be predictive of the ictal onset zone in a subset of patients with neocortical epilepsy. SIGNIFICANCE These results support the utility of beamformer source localization as a fast semi-automated method for source localization of interictal spikes and planning the surgical strategy.

Neuromagnetic cerebellar activation during seizures arising from the motor cortex

We utilized the high temporal resolution, whole head coverage and novel analysis methodology of magnetoencephalography (MEG) to record the dynamics of cerebellar activation during focal motor seizures. We analyzed ictal MEG data from a four-year old using an event-related beamformer to localize and display ictal changes over the motor cortex and cerebellum. Contralateral activation of the cerebellum was seen 14s after MEG ictal onset over the motor cortex. These findings represent the first indication of ictal activity within the cerebellum in humans, measured non-invasively with MEG.

Cost-utility analysis of magnetoencephalography used to inform intracranial electrode placement in patients with drug resistant epilepsy: a model based analysis.

OBJECTIVES We estimated the cost-effectiveness of adding magnetoencephalography to a standard assessment for epilepsy surgery consisting of neuropsychology, magnetic resonance imagining, scalp electroencephalography, video electroencephalography and intracranial electroencephalography, in the capacity of informing intracranial electroencephalography electrode placement. METHODS We used Microsoft Excel (2007) to construct a decision model. Discounted costs and quality adjusted life years are aggregated to calculate incremental cost-effectiveness ratios. Sensitivity analyses are conducted to assess robustness of findings. RESULTS Our base case analysis yielded a result of

What Do Patients and Families Want From a Child Neurology Consultation

14 300 per quality adjusted life year gained. A total of 82.7% of probabilistic sensitivity analysis iterations resulted in incremental cost-effectiveness ratios below