Abstracts

Rationale: Traditional surgical interventions in non-lesional frontal lobe epilepsy can have low rates of success. There are several predictors of poor surgical outcome including failure to identify focal ictal onset zone (IOZ), bilateral, independent IOZs, and rapid secondary bilateral synchrony1. We report a case of a developmentally normal patient with over 20 year history of uncontrolled frontal lobe seizures causing frequent drop attacks who achieved Engel class II outcome following a combined surgery which included anterior 2/3 callosotomy, tailored left frontal resection and contralateral Neuropace implantation. 1JAMA Neurol. 2013 Aug;70(8):1003-8. Methods: A 34 yo right handed woman was evaluated for medically refractory epilepsy. Epilepsy began at age 12 without risk factors. She tried and failed all available anticonvulsant medications and VNS placement (2005). Seizures occurred daily to weekly, often in clusters, frequently resulting in falls. Seizure semiology was extension of all 4 extremities, some with left arm flexion and longer ones associated with fine clonic activity. Typical duration was 30 ?" 120 sec with minimal post-ictal state. Work up included normal MR imaging of the brain in 1993, 2005, 2008. 3T MRI and PET in 10/14 were normal. Ictal SPECT in 2015 showed increased activity in bilateral parasagittal frontal lobes, slightly more on right. She underwent several EMU admissions for scalp EEG monitoring. In 2005 at Stanford University: 30 to 40 tonic seizures per night with polyspike activity over the vertex. In 2009 at Maine Medical Center: 26 seizures with a generalized electro-decremental pattern. Repeat study in 10/14 recorded 14 events and EEG demonstrated abrupt attenuation of activity with electrodecrement, diffuse low amplitude beta and EMG artifact without localizing features. She underwent anterior 2/3 callosotomy in 11/14 with no obvious benefit. Re-evaluation at DHMC with scalp monitoring in 4/15 recorded 80 seizures. No clear lateralizing findings were seen on EEG. Clinically asymmetric dystonic posturing, with extension of right arm, favored a L SMA focus. At DHMC the patient then had an intra-cranial EEG study with bifrontal strips and an interhemispheric grid. She had a majority of seizures arising from left medial frontal lobe; a smaller number had right medial frontal onset. Both seizure types showed low amplitude fast sharp activity at onset. During surgery it was also evident that the prior callosotomy had left part of the genu intact. On 1/22/16 she underwent left medial frontal resection, completion of the anterior callosotomy and implantation of a NeuroPace device with four 4-contact strip electrodes over the right medial frontal cortex. Results: Outcome: As of 4.5 month post-operative, she has been seizure free with the exception of brief recurrence attributed to medication errors during transition to the rehabilitation hospital. Electrocorticography from NeuroPace interrogation shows bursts of low amplitude fast sharp activity in the right medial frontal region, but no clinical seizures (figure 1). NeuroPace stimulation is being done via 2 of the 4 implanted strip electrodes. She is receiving several hundred stimulations daily. She remains on her pre-operative medical regimen of topiramate, levetiracetam and clobazam. Conclusions: This patient demonstrates that when patients have life-threatening partial seizures, marked improvement is possible with a multi-modal surgical approach, even when they have multiple factors previously associated with poor surgical outcome. Longer follow up is necessary to determine whether or not her benefit is sustained. Funding: None