Authors :
Presenting Author: Dorian Kusyk, MD – Allegheny Health Network
Nicholas Blaney, BS – Drexel University School of Medicine; Timothy Quezada, DO – Neurology – Allegheny Health Network; Alexander Whiting, MD – Allegheny Health Network
Rationale:
Responsive neural stimulation (RNS) is a relatively novel procedure performed for drug resistant epilepsy, which involves implantation of a device into the skull and brain. As more patients are implanted with this device, there may increasingly be a need to perform intracranial electrocorticography in implanted patients presenting with inadequate seizure control. Given the location of the device in the skull, imaging difficulties with implanted devices, and other technical hurdles, stereoelectroencephalography (SEEG) could be especially challenging. We describe the first reported SEEG investigation in a patient with a previously implanted RNS device, highlighting the technical challenges and clinical data ascertained
Methods:
A 41-year-old male with drug resistant epilepsy presented to our clinic several years after a local surgeon placed an RNS device with two depth electrodes in the bilateral parieto-occipital lobes. Given inadequate seizure control, the patient was offered a repeat SEEG investigation to better characterize his epilepsy.
Results:
While more technically challenging than a traditional SEEG implantation, the patient underwent successful SEEG investigation with 12 electrodes without complication or damage to the RNS device (Figure 1). His phase 2 evaluation led to a confirmation of left hippocampus seizure onset with rapid spread to the contralateral side (Figure 2). He underwent repositioning of his RNS leads with a significant decrease in his seizure frequency.
Conclusions:
Phase 2 SEEG investigation can be safely and effectively performed in the setting of an implanted RNS implant, directing further epilepsy treatment. Concurrent implantation of SEEG electrodes in a functioning RNS device can augment understanding of how the system is responding to seizures occurring remotely from the electrodes.
Funding: This study was unfunded.