Title : Innovative sEEG based device for neural recordings, ablation and drug delivery into the brain
Abstract:
Stereoelectroencephalography (sEEG) electrodes are routinely used to identify the epileptogenic zone (EZ) in patients with drug resistant epilepsy. The sEEG electrodes are FDA-cleared for temporary (<30 days) neural activity monitoring, recording and stimulation. Here we present bench and in vivo studies for two new clinical functions added to the sEEG electrodes: 1) temperature-controlled radiofrequency ablation (RFA) and 2) convection enhanced drug delivery (CED).
Methods: RFA was tested in ex vivo chicken breast and in vivo swine brain, using a proprietary RF generator. Lesions obtained for different ablation parameters (time and temperature) were evaluated with MRI and histology. CED was tested in 0.6% agarose gel. Concomitant neural recordings and CED were evaluated in rat and swine models. DD-sEEG electrodes were stereotactically implanted into the hippocampus (HC) and putamen (PUT), and penicillin (5000 units/µl) was used to modulate neural activity. MRI with gadolinium (Gd; swine) and histology (rat) were used to evaluate diffusion volume (Vd).
Results: sEEG-guided RFA created reproducible lesions with sizes proportional to temperature and time. In vivo and ex vivo lesions were comparable and varied between 4 and 10 mm in diameter, depending on the RFA parameters. Bench studies demonstrated CED for infusion rates of 0.5-15 µl/min and infused volumes (Vi) of 100-1000 µl, with Vd/Vi ratio of 2.7-3.4. Penicillin elicited seizure-like episodes, consisting of large amplitude bursts of coordinated activity interspaced by quiet periods, in both rat and swine HC. MRI visualization of Gd demonstrated localized infusions in the swine PUT and HC. Histological examination of the rat brain tissue showed confined Vd.
Conclusions: These data demonstrate the ability of a single sEEG-based device platform to perform multiple functions: record brain activity, stimulate, ablate and deliver drugs. This has the potential to increase the accuracy of diagnosis and offer treatment within one surgical procedure. Furthermore, real time monitoring of neural activity during infusion of therapeutic compounds can be used to probe the function of various brain structures, and/or evaluate onset and mechanism of action, dosing, efficacy and safety of therapeutic compounds.
Audience Take Away Notes:
- Learn about available research and clinical tools for probing neural activity using combined pharmacological and surgical approaches.
- Learn about a modular device platform that enables diagnosis and treatment within a single procedure.
- Learn about a new device that monitors neural activity in real-time during therapeutic compound delivery (drugs, gene and stem cell therapies).
