Seizure Occurrences: Patient Report, Scalp EEG, and RNS Electrocorticography Findings

Eliminating or reducing seizures is a main goal of epilepsy treatment, and clinicians rely mainly on patient self-report regarding seizure frequency. Here, we compare seizure frequency by patient report with responsive neurostimulation (RNS) recordings in two patients, one of whom also had prolonged scalp EEG recording. RNS being more sensitive in detecting seizures than scalp EEG, our cases illustrate that patients may strikingly underreport seizure frequency. In addition, patients may also overreport seizures. Although a negative scalp EEG study does not exclude the possibility of focal aware seizures, RNS can reliably differentiate between nonepileptic events and focal aware seizures if electrodes are properly placed in the seizure-onset zone. Besides its therapeutic benefit, RNS can also play an important role in identifying seizure frequency. Improving seizure monitoring using the device could help to optimize therapy and outcome.