George Nune1, Sharanya Arcot Desai2, Babak Razavi3, Mark A Agostini4, Gregory K Bergey5, Aamr A Herekar6, Lawrence J Hirsch7, Ricky W Lee8, Paul A Rutecki9, Shraddha Srinivasan10, Paul C Van Ness11, Thomas K Tcheng12, Martha J Morrell13. 1. Keck School of Medicine of University of Southern California, Los Angeles, CA, USA. 2. NeuroPace, Inc., Mountain View, CA, USA. Electronic address: sdesai@neuropace.com. 3. Stanford University, Stanford, CA, USA. 4. University of Texas Southwestern Medical Center, Dallas, TX, USA. 5. Johns Hopkins School of Medicine, Baltimore, MD, USA. 6. University of North Texas, Medical City Fort Worth, Fort Worth, TX, USA. 7. Yale University School of Medicine, New Haven, CT, USA. 8. Via Christi Epilepsy Center, Wichita, KS, USA. 9. University of Wisconsin Hospital and Clinics, Madison, WI, USA. 10. Columbia University Medical Center, New York, NY, USA. 11. Baylor College of Medicine, Houston, TX, USA. 12. NeuroPace, Inc., Mountain View, CA, USA. 13. NeuroPace, Inc., Mountain View, CA, USA; Stanford University, Stanford, CA, USA.
Abstract
OBJECTIVES: Describe changes in clinical seizure frequency and electrophysiological data recorded in patients with medically-intractable seizures and periventricular nodular heterotopias (PVNH) treated with the RNS® System (NeuroPace, Inc., Mountain View, CA). METHODS: Clinical seizures from eight patients (mean follow-up of 10.1 years) were analyzed pre- and post-treatment. Chronic ambulatory electrocorticograms (ECoGs) recorded from PVNHs, hippocampus and neocortex were evaluated to identify the earliest electrographic seizure onset type, pattern of spread, and interictal characteristics. RESULTS: Mean reduction in disabling seizures was 85.7 % (n = 8); seven patients had >50% seizure reduction and two were seizure-free in the final year of analysis. Seizure rate showed a progressive reduction over the course of the study with the highest rate of improvement in the first two to three years after implantation. Four of seven patients with one PVNH lead and a second lead in the hippocampus or neocortex had some electrographic seizures first recorded at either lead location, suggesting two foci or seizure propagation patterns. Low voltage fast type activity was the prominent seizure onset pattern. Interictal ECoG power was lower in PVNH than hippocampus. CONCLUSIONS: RNS® System treatment substantially reduced clinical seizure frequency in patients with PVNH. Analysis of ictal ECoG records suggests PVNH may be involved in seizure generation. SIGNIFICANCE: Chronic ECoG recordings suggest PVNH tissue can actively participate in epileptogenic networks. Direct brain-responsive neurostimulation is a safe and effective treatment option in such patients, progressively reducing seizure rate over a period of years.
OBJECTIVES: Describe changes in clinical seizure frequency and electrophysiological data recorded in patients with medically-intractable seizures and periventricular nodular heterotopias (PVNH) treated with the RNS® System (NeuroPace, Inc., Mountain View, CA). METHODS: Clinical seizures from eight patients (mean follow-up of 10.1 years) were analyzed pre- and post-treatment. Chronic ambulatory electrocorticograms (ECoGs) recorded from PVNHs, hippocampus and neocortex were evaluated to identify the earliest electrographic seizure onset type, pattern of spread, and interictal characteristics. RESULTS: Mean reduction in disabling seizures was 85.7 % (n = 8); seven patients had >50% seizure reduction and two were seizure-free in the final year of analysis. Seizure rate showed a progressive reduction over the course of the study with the highest rate of improvement in the first two to three years after implantation. Four of seven patients with one PVNH lead and a second lead in the hippocampus or neocortex had some electrographic seizures first recorded at either lead location, suggesting two foci or seizure propagation patterns. Low voltage fast type activity was the prominent seizure onset pattern. Interictal ECoG power was lower in PVNH than hippocampus. CONCLUSIONS:RNS® System treatment substantially reduced clinical seizure frequency in patients with PVNH. Analysis of ictal ECoG records suggests PVNH may be involved in seizure generation. SIGNIFICANCE: Chronic ECoG recordings suggest PVNH tissue can actively participate in epileptogenic networks. Direct brain-responsive neurostimulation is a safe and effective treatment option in such patients, progressively reducing seizure rate over a period of years.