Characterization of Spinal Cord Stimulation Electrode for Chronic Implant in Animal Models

• Published in: Engineering proceedings Vol. 35; no. 1; p. 34
• Main Authors: Leila Cavalcanti, Gilberto Filho, Raquel Medeiros, Hudson Diniz, Igor Damasceno, Edgard Morya, Hougelle Simplício
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.05.2023
• Subjects: invasive microelectrode; microelectrode; platinum; roughness; spinal cord stimulation; wettability
• ISSN: 2673-4591
• DOI: 10.3390/IECB2023-14579

Spinal cord electrical (SCS) stimulation alleviates motor deficits in rodent and primate models of Parkinson’s disease due to a suppression of synchronous corticostriatal low-frequency oscillation. Limited epidural space requires resistant biocompatible microelectrodes to deliver efficiently electrical currents through a metal–cellular interface. Platinum (Pt) microelectrodes may lead to material degradation and topography modification under prolonged electrical stimulation. Thus, microstimulation performance over time can deteriorate and affect the functional recovery produced by SCS. To investigate electrodes commonly implanted in the epidural space of rats, Pt microelectrodes immersed in physiological saline underwent 48 h of electrical stimulation (100 Hz; 1.0, 1.3, and 1.6 mA). A wettability test was performed to characterize the interaction of the contact angle before and after stimulation, and it was found that there was an increase in this angle after the stimulation. An electrical impedance test showed that electrochemical interactions caused an increase in impedance after the stimulation. A roughness analysis also showed an increase in roughness after stimulation. Pt electrodes under chronic electric stimulation are susceptible to degradation, and further studies can improve electrode stability and efficacy as new sensor technologies become available.