A novel implantable vagus nerve stimulation system (ADNS-300) for combined stimulation and recording of the vagus nerve: Pilot trial at Ghent University Hospital

• Published in: Epilepsy research Vol. 92; no. 2; pp. 231 - 239
• Main Authors: El Tahry, Riëm, Raedt, Robrecht, Mollet, Lies, De Herdt, Veerle, Wyckuys, Tine, Van Dycke, Annelies, Meurs, Alfred, Dewaele, Frank, Van Roost, Dirk, Doguet, Pascal, Delbeke, Jean, Wadman, Wytse, Vonck, Kristl, Boon, Paul
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.12.2010; Elsevier
• Subjects: Action potential; Action Potentials - physiology; Adult; Anticonvulsants. Antiepileptics. Antiparkinson agents; Biological and medical sciences; Compound action potentials; Electrodes, Implanted; Epilepsy; Epilepsy - physiopathology; Epilepsy - therapy; Female; Follow-Up Studies; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Hospitals, University; Humans; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Neuropharmacology; Pharmacology. Drug treatments; Pilot Projects; Treatment Outcome; Vagus Nerve - physiology; Vagus Nerve - physiopathology; Vagus nerve stimulation; Vagus Nerve Stimulation - instrumentation; Vagus Nerve Stimulation - methods; Vagus nerve stimulation; Epilepsy; Compound action potentials; Nervous system diseases; Central nervous system disease; Electrophysiology; Action potential; Vagus nerve; Cerebral disorder
• ISSN: 0920-1211; 1872-6844
• DOI: 10.1016/j.eplepsyres.2010.10.007

Summary Purpose Vagus nerve stimulation (VNS) is an established treatment for refractory epilepsy. The ADNS-300 is a new system for VNS that includes a rechargeable stimulus generator and an electrode for combined stimulation and recording. In this feasibility study, three patients were implanted with ADNS-300 for therapeutic VNS. In addition, compound action potentials (CAPs) were recorded to evaluate activation of the vagus nerve in response to VNS. Methods Three patients were implanted with a cuff-electrode around the left vagus nerve, that was connected to a rechargeable pulse generator under the left clavicula. Two weeks after surgery, therapeutic VNS (0.25–1.25 mA, 500 μs, 30 s on, 10 min off and 30 Hz) was initiated and stimulus-induced CAPs were recorded. Results The ADNS-300 system was successfully implanted in all three patients and patients were appropriately stimulated during six months of follow-up. A reduction in seizure frequency was demonstrated in two patients (43% and 40% in patients 1 and 3, respectively), while in patient 2 seizure frequency remained unchanged. CAPs could be recorded in patients 1 and 2, proving stimulation-induced activation of the vagus nerve. Conclusion This feasibility study demonstrates that the ADNS-300 system can be used for combined therapeutic stimulation (in 3/3 patients) and recording of CAPs in response to VNS (in 2/3 patients) up to three weeks after surgery. Implantation in a larger number of patients will lead to a better understanding of the electrophysiology of the vagus nerve, which in turn could result in more adequate and individualized VNS parameter choice.