A Case Report of Multitrack Recording of Posterior Subthalamic Nucleus, Caudal Zona Incerta, and Prelemniscal Radiation: Which Is Most Effective for Bradykinesia?

Deep brain stimulation (DBS) of the posterior subthalamic nucleus (pSTN), caudal zona incerta (cZI), and prelemniscal radiation (Raprl) has been shown to improve Parkinsonian motor symptoms. We herein report neurophysiological and functional differences among the cZI, Raprl, and pSTN in a 68-year-old male patient with Parkinson’s disease (PD). The stereotactic implantation of DBS electrodes in the right STN was performed. Thereafter, a transfrontal trajectory for the left cZI was planned for left side implantation, with the expectation that the electrode entered the pSTN in the case of a posterior brain shift. In the implantation of the DBS lead in the cZI, three microelectrodes were simultaneously placed in an array with the central, medial, and anterior positions placed 2 mm apart to delineate the cZI, Raprl, and pSTN, respectively. A maximal reduction in bradykinesia was obtained from the stimulation of the pSTN at the lowest voltage thresholds, and the voltage threshold for abolishing tremors was lower in the Raprl and cZI than in the pSTN. The left DBS lead was implanted in the pSTN because right-sided bradykinesia was more severe than tremor. The multitrack recording of cZI, Raprl, and pSTN might broaden target selection depending on patients’ symptoms.