Abstracts

Rationale: While ictal and peri-ictal arrhythmias have been well-studied and noted to be in increased cause of death in Persons With Epilepsy (PWE), less is known about long-standing interictal arrhythmias in PWE compared to the general population, and even less regarding potential for correction with neuromodulation in PWE if significant reduction in seizure burden is obtained.



This case highlights findings from a young woman with medically refractory left temporal lobe epilepsy (TLE) regarding a long-standing arrhythmia involving frequent Premature Ventricular Contractions (PVCs) and ventricular bigeminy of at least 6 years time, with an observed EKG normalization 1 year after Responsive Neurostimulation (RNS) device implantation and initiation.


Methods: Case Report

Results: A 26-year-old woman with medically-intractable epilepsy underwent admission to an Epilepsy Monitoring Unit (EMU) for surgical candidacy evaluation for the first time in 2017, when incidental finding of ventricular bigeminy was noted interictally, with no significant findings on cardiologic workup. 4 seizures captured on scalp-EEG showed left-temporal localization corresponding with a L temporal pole cavernous malformation, and the patient underwent Laser Interstitial Thermal Therapy (LITT) later that year, which was initially successful, but breakthrough seizures returned approximately 2.5 years later.

She underwent additional EMU admission in 2023, 6 years after her previous admission, and throughout her stay again displayed frequent PVCs interictally, often with complete ventricular bigeminy observed. 3 seizures were captured that correlated with previously-observed left-temporal lobe onset. She underwent RNS implantation with a left hippocampal depth electrode and left lateral subtemporal cortical strip, and neurostimulation was initiated in June 2023.



The patient, now aware of frequent PVCs being a long-standing finding, began occasional monitoring with 30-second EKG recordings using an Apple watch. Most EKGs post-operatively revealed either ventricular bigeminy or frequent PVCs throughout, consistent with EMU-observed findings. As the patient's RNS stimulation was adjusted with algorithm optimization and increasing current over time, however, she showed significant reduction in seizure burden > 90% at the 1-year mark, with no disabling seizures after 5 months of neuromodulation. Interestingly, review of patient’s continued EKG recordings via Apple watch over this 1-year period also eventually showed a gross reduction and eventual elimination of frequent PVCs.


Conclusions: Review of this patient’s EKG data and RNS feedback shows an apparent correlation of decreased seizure burden with reduction and eventual elimination of frequent PVCs that had been present for at least 6 years time, with no other known contributory factors to its potential cause or correction. While decreased seizure burden is the primary goal of neuromodulation, the potential to reduce chronic interictal arrhythmias as seen in this patient remains a great possible benefit that could be seen in other patients in the future, in addition to the ability to support primary neurologic etiology for interictal arrhythmias.


Funding: None