Rationale:
NeuroPace is an FDA-approved Responsive Neurostimulation System (RNS) for improving real-time seizure detection and optimizing treatment. We admitted a patient to the Epilepsy Monitoring Unit (EMU) to examine whether observable clinical correlates were detected during seizure activity captured by the NeuroPace Patient Data Management System (PDMS) and scalp continuous video electroencephalogram (cEEG).
Our patient requested medical clearance to drive in his rural Virginia town since he endorsed no clinical seizures for over two years. However, cEEG and PDMS data showed multiple electrographic seizures. Current guidelines do not include recommendations for PDMS data, only stating that patients who endorse at least six months of seizure freedom may drive.
Methods:
A 37-year-old male with refractory left temporal epilepsy diagnosed at age three, on three anti-epileptic drugs, and with a Neuropace implant since 2020 was admitted to the EMU. He reported no seizures since 2019. We collected cEEG and PDMS data and conducted a comprehensive neuropsychological evaluation.
Results:
cEEG revealed brief electrographic seizures originating from the left and right anterior temporal regions, occurring mainly on the left side. The seizures were characterized by interictal prominent anterior temporal sharps, with a left-sided predominance. PDMS data showed similar results, but recorded electrographic seizures in excess of cEEG. There were no behavioral observations of clinical seizures during these recorded electrographic seizures. The patient also reported no seizures.
Neuropsychological results showed impaired performance in visual and verbal learning, memory for verbal and complex visuospatial information, confrontation naming, and processing speed. His performance on tasks of executive functions varied. This impaired neurocognitive presentation may be influenced by chronic epilepsy, bitemporal epileptiform activity, and polypharmacy.
Conclusions:
Current practice allows patients who report no clinical seizures for at least six months medical clearance to drive, although this varies by state. No guidelines exist for incorporating PDMS data, raising ethical dilemmas for physicians. More comprehensive guidelines are especially important when information conflicts. In this case, although cEEG and NeuroPace showed seizure activity and neuropsychological testing showed cognitive impairment in multiple domains, there were no clinically perceptible seizures.
This case highlights the need for a more nuanced approach to determining allowable electrographic activity since these thresholds directly impact restrictions on patients with epilepsy. Highly sensitive measurement tools better detect seizures but in isolation cannot fully convey a patient’s condition. Data from emerging technology must be weighed in conjunction with clinical symptoms to optimize patient safety, quality of life, and outcomes.
Funding:
N/A