BACKGROUND/ OBJECTIVES: To better understand the mechanism of action of deep brain stimulation (DBS) for epilepsy and to investigate implantable device features, it is desirable to have a large animal model to evaluate clinical-grade systems. This study assessed the suitability of an ovine model of epilepsy for this purpose. METHODS: Animals were anesthetized for surgery and 1.5 T MRIs collected. Unilateral anterior thalamic DBS leads, hippocampal depth electrodes and catheters were implanted using a frameless stereotactic system. Evoked responses and local field potentials were collected and stored for off-line analysis. RESULTS: Despite limited neuroanatomic information for this species, it was possible to reliably implant leads into the target structures using MR-guided techniques. Stimulation of these regions produced robust evoked potentials within this circuit that were dependent on stimulus location and parameters. High-frequency thalamic DBS produced a clear inhibition of both spontaneous and penicillin-induced ictal activity in the hippocampus which far outlasted the duration of the stimulation. CONCLUSIONS: These preliminary results suggest that the sheep model may be useful for further investigation of DBS for epilepsy. The demonstration of marked suppression of network excitability with high-frequency stimulation supports a potential therapeutic mechanism for this DBS therapy.
BACKGROUND/ OBJECTIVES: To better understand the mechanism of action of deep brain stimulation (DBS) for epilepsy and to investigate implantable device features, it is desirable to have a large animal model to evaluate clinical-grade systems. This study assessed the suitability of an ovine model of epilepsy for this purpose. METHODS: Animals were anesthetized for surgery and 1.5 T MRIs collected. Unilateral anterior thalamic DBS leads, hippocampal depth electrodes and catheters were implanted using a frameless stereotactic system. Evoked responses and local field potentials were collected and stored for off-line analysis. RESULTS: Despite limited neuroanatomic information for this species, it was possible to reliably implant leads into the target structures using MR-guided techniques. Stimulation of these regions produced robust evoked potentials within this circuit that were dependent on stimulus location and parameters. High-frequency thalamic DBS produced a clear inhibition of both spontaneous and penicillin-induced ictal activity in the hippocampus which far outlasted the duration of the stimulation. CONCLUSIONS: These preliminary results suggest that the sheep model may be useful for further investigation of DBS for epilepsy. The demonstration of marked suppression of network excitability with high-frequency stimulation supports a potential therapeutic mechanism for this DBS therapy.
Authors: Kishan Andre Liyanage; Christopher Steward; Bradford Armstrong Moffat; Nicholas Lachlan Opie; Gil Simon Rind; Sam Emmanuel John; Stephen Ronayne; Clive Newton May; Terence John O'Brien; Marjorie Eileen Milne; Thomas James Oxley Journal: PLoS One Date: 2016-06-10 Impact factor: 3.240
Authors: Pedram Afshar; Ankit Khambhati; Scott Stanslaski; David Carlson; Randy Jensen; Dave Linde; Siddharth Dani; Maciej Lazarewicz; Peng Cong; Jon Giftakis; Paul Stypulkowski; Tim Denison Journal: Front Neural Circuits Date: 2013-01-22 Impact factor: 3.492