Abstracts

Rationale: Epilepsy is a network disease. Both structural and functional network are being investigated with variety of non-invasive neuroimaging technologies. Magnetoencephalography (MEG), electroencephalography (EEG), functional magnetic resonance imaging (functional MRI) have been applied for functional network investigation. MRI is the best tool for investigating structural network non-invasively. We reviewed 2 pediatric epilepsy patients who had MRI 6 and 2 months of age .   Methods: TA and KK's  epilepsy started at 8 days and 3 months. Both patients are medically refractory. During the presurgical evaluation, they underwent MEG study with a whole head system with 148 MEG channel. MRI were acquired on a Siemens 3 Tesla scanner with standard epilepsy protocol, TA also had diffusion tensor imaging (DTI).   Results: TA. 6-month-old female, her seizure started at 3 months of age, multiple seizures daily with left arm tonic extension followed by clonic activity. EEG demonstrates right frontal onset. MEG revealed majority of interitcal epileptiform discharges at right frontal lobe (Figure-B). MRI T1 weighted image demonstrates thickened gray matter, accelerated over-developed myelination (star on Figure-B) and aberrant finber tract (Figure A) on right frontal lobe. Seed in the right frontal lobe, the aberrant fiber projects to left frontal lobe and posteriorly medial to the left caudate nucleus on FA map(Figure C). The patient underwent right frontal lobectomy and anterior corpus callosotomy with intraoperative EEG guidance (Figure-D). She remains seizure free 23 months after surgery.KK is 2 month-old-male, his seizure started 8 days after birth, with jerking of 4 extremities and eye deviation (10-20 seconds, 4-5 per day). EEG demonstrates left posterior quadrant onset. MEG study could not map the somatosensory function of her left hemisphere. MRI revealed left posterior partial hemimegalencephaly. There is significant accelerated myelination associated with the thickened the dysplastic cortex. The patient underwent left functional hemispherectomy. The patient has not had seizure one month after surgery.   Conclusions: Based on our limited data, we confirmed that accelerated myelination and aberrant tracts can be found in patients with cortical developmental disorders, such as partial hemimegalencephaly. The accelerated myelination region and aberrant tract is related to epileptogenic zone and may be part of the epileptic network. Funding: N/A