Abstracts

Rationale: Self-reported seizure frequencies, particularly in patients with refractory temporal lobe epilepsy, are often unreliable. Responsive neurostimulation systems (RNS, NeuroPace) rely on identification of physician-selected patterns of cortical excitability they wish to stimulate to help stop development or propagation of seizure activity. The RNS system effectively counts detections and stimulations (DSC) which can be used to individualize not just stimulator based therapy, but medical therapy as well. In this report we investigate mirtazapine-induced DSC changes in cortical excitability in a patient with a RNS device recording from bilateral hippocampi Methods: Eighteen days of detection/stimulation counts from an RNS implanted in a patient with bitemporal epilepsy were matched to mirtazapine use to see if that drug altered hippocampal excitability. Results: Mirtazapine decreased nocturnal hippocampal stability. In a six day period average DSC counts were elevated with mirtazapine use. When mirtazapine was held after a washout period, six day average DSC declined, when retrialed again over 6 days, average DSC counts again increased. RNS systems data helped us design a less dangerous and individualized medication regimen for our refractory epilepsy patient. Conclusions: RNS systems showed Mirtazapine worsened hippocampal excitability in a patient with bitemporal epilepsy. In this patient DSC counts during medication trial, washout and retrial stages helped verify specific and important drug effects on cortical instabilities. Individualized therapy decisions using RNS system DSC data matched to medication uses can help identify pro-epileptic drug effects. Similar strategies presumably could be used in surveying how effective conventional anti-epileptic drug controls are. Funding: This study was not funded