Dual microelectrode technique for deep brain stereotactic surgery in humans

OBJECTIVE: To improve functional stereotactic microelectrode localization of small deep brain structures by developing and evaluating a recording system with two closely separated independently controlled microelectrodes. METHODS: Data were obtained from 52 patients using this dual microelectrode technique and 38 patients using the standard single microelectrode technique for subthalamic nucleus localization in patients with Parkinson's disease. RESULTS: There was a decrease in the incidence of noncontributory trajectories, defined as a single penetration made by the pair of closely spaced parallel microelectrodes, owing to microelectrode failure (from 7.2% to < 1%), an improved localization and verification of nuclear borders, and a significant decrease in the number of trajectories used to localize the subthalamic nucleus from a median of three to two per initial operative side (P < 0.001). The technique also provides the novel opportunity to examine population activity by correlating the discharge between two closely spaced simultaneously recorded neurons and can be used to monitor the electrophysiological effects of local electrical stimulation or microinjections of pharmacological agents. CONCLUSION: Our experience indicates that the use of two closely spaced microelectrodes improves the utility of microelectrode localization in minimally invasive functional neurosurgery.